Electrostatic air filter

FIELD: treatment facilities.

SUBSTANCE: invention is related to filtering materials for cleaning of gaseous medium, in which nanosize first fibres of aluminium oxide and second fibres are arranged in the form of matrix with formation of asymmetric pores, at the same time each of specified second fibres has diametre in the range from approximately 0.6 mcm to approximately 3.5 mcm, at the same time asymmetric pores have average size of more than approximately 10 mcm and less then approximately 38 mcm, material may retain particles, size of which is many times less than specified pore size.

EFFECT: according to invention, filter has high efficiency of filtration and high absorbing property.

47 cl, 7 tbl, 14 dwg, 10 ex

 

Cross-reference to related application

This application claims priority on provisional application for U.S. patent No. 60/716218 called "Electrostatic Air Filter", filed September 12, 2005

The public interest

This invention was created in connection with the execution of a research project supported by the Air Forces of the United States, contract # FA8650-05-M-5822, the period from 2 may 2005 to 15 November 2005, Respectively, the U.S. government has certain rights to this invention.

The technical field to which the invention relates.

This invention relates to nanofibers and, in particular, to the use of nanofibers aluminum oxide in mixtures used in air and gas filters.

The level of technology

Air quality inside and outside has become in the last two decades, an important subject of discussion in the aspect of occupational health, political and scientific aspects in connection with the fight against environmental pollution. Air and gas streams carry different particles. The removal of these particles improves air quality and reduces the risk of infection or other diseases resulting from air pollution, which is caused by these aerosol particles. Good air quality is especially important for those who suffer from respiratory diseases, t is such as asthma.

One of the main sources of infection are the microorganisms present in the air when removed from the state of rest the soil, water, dust and decaying organic matter. They can be transported inside the premises by many media, including people, air flow, water, equipment, or construction materials. Once in the room, accompanying microorganisms can multiply rapidly in various environmental compartments inside and then later released into the air can be a source of airborne infections.

In addition, pathogens such as influenza virus, rhinoviruses, adenoviruses, respiratory syncytial virus (RSV), tuberculosis, and measles virus can be spread in aerosol form of oral and nasal secretions. Often these pathogens are contained in the droplets or nuclei droplet size in the range from 1 μm to 5 μm. These droplets remain suspended indefinitely in the air and can travel long distances. Spreading viruses in the air may get worse when you cough or sneeze, when the cloud of pathogens spread in the air.

In addition, many industries form a significant amount of liquid aerosols, which contribute to air pollution within the esani. Examples of such liquid aerosols are: mists formed by fluids for metal working in industries related to machining; the mists of paint materials from the automotive industry; pesticides used in agricultural production; the mists of ink from the printing industry; and acid mists formed in the chemical industry. Not only the negative impact of these liquid aerosols on health workers, but also standards for the protection of the environment, which are becoming more stringent, require the use of more efficient filters to reduce air pollution and improve its quality.

Transfer by air substances in the form of microparticles, including the transfer in the form of liquid aerosols is also a particular problem in health care, contributing about 103000 deaths each year caused by infections in U.S. hospitals. Susceptibility to these pathogens carried by air, is greatest among immunocompromised patients such as the elderly, patients with burns and patients subjected to implantation or chemotherapy. Surgeons and other medical workers are also exposed to pathogenic ICRI the organisms, portable liquid aerosols in operating, and are at risk of infection with these pathogens reaching the nasal mucosa. For example, the air may be polluted by such viruses and bacteria, as the human papilloma virus (HPV), human immunodeficiency virus (HIV) and staphylococci (Staphylococcus), which are released into the plume from the laser surgical instrument used in the sections of bones. As another example, in the distribution systems of warm water usually are varieties of Legionella (Legionella), which can propagate in the air space above them. Distilled water is collected in the field, creates an environment in which Legionella can multiply. In the case of some disease outbreaks in hospitals, health workers were identified that patients were infected by exposure to contaminated aerosols generated by cooling towers, showers, water taps, equipment for respiratory therapy and respiratory therapy, and moisturizers room air.

Air filters are a means by which consumers, industry and health care institutions equally expect to improve air quality. For example, many consumers use home voozduhoochistitel filters in vacuum cleaners to improve air quality at home. Health care workers and workers of industrial enterprises often rely on facial masks to protect themselves from substances in the form of particles and pathogens, airborne. The most commonly used form of air and gas filter is a filter that contains a HEPA filter medium (air filtration with high latency particles). Filter media HEPA able to hold >99.97% of particles 0.3 microns and consist of a sheet of non-woven material formed of glass and/or polymer fibers with a diameter in the range of from about 0.5 to about 10 microns. These filters are mainly used in filtration systems of collective security (premises), although they can also be used in respirators. Filter medium for air filter with a low pass particles (ULPA) is able to delay 99.99% of particles of a certain size at a given speed, the noise environment. SULPA filters (Super ULPA) suitable for use in cases when you want maximum purity. These filters have an efficiency of 99,9999% under the same conditions as the ULPA filters.

Despite the extremely high capacity air filters HEPA delay substances in the air or gas flows, these conventional filter media HEPA allow the transmission fluid that is radicial their effectiveness against capture or delay of pathogenic microorganisms from liquid aerosols. Clogging liquid aerosol occurs when the particles of a liquid, in particular water aerosols accumulate on the fibers and form a thin film on each of the fibers. When this film brings together several of the fibers, the liquid layers are formed, or bridges that restrict the flow and quickly increase the differential pressure, which ultimately leads to reduced efficiency of the filter. Essentially, those who rely on filters to protect against pathogens and other particles present in a liquid aerosols remain susceptible to infection, because the functionality of the filter media available at the present time, less effective under such circumstances.

In the art it is known the use of nanofibers that are distributed over the glass microfibers, for filtering submicron particles from the water. However, such filters have a high differential pressure, which negatively affects their effectiveness when used as an air or gas filters. For example, in U.S. Patent No. 6838005 described filter based on nano-sized aluminum oxide, which is effective to filter out viruses from water. Until the present invention generally believed that any attempt to reduce the pressure drop of the filters of nanoscale aluminum oxide would require pore size, that would be too large to filter fine particles from the air. In addition, it was suggested that should the water environment, to implement the electrokinetic potential of nanoscale aluminum oxide and, respectively, its electrostatic advantages that prevents its use as an air filter.

In addition, the energy spent to overcome the pressure drop in the filter, often costs more than the filter itself. In systems with HEPA filter, the cost of energy consumed may be four to five times the initial cost of the filter. Therefore, a filter that provides reduced pressure drop over the entire service life of the filter, would provide significant savings. In addition, in cases where the filter material is used in medicine or wherever it may contain bacteria, the cost of waste disposal increases significantly, since the filter material is considered as dangerous biologically waste. Accordingly, extended life filter minimizes the frequency of elimination of hazardous biologically filters and thereby reduces costs.

In accordance with the foregoing consumers, health care institutions and in various industries has the needs of the ü in cost-effective high-performance filter, which retains the particles at the level of at least the same high that HEPA filters, but which is also capable of keeping the bacteria in the water spray, and which is superior to conventional HEPA filters for air purification. Such filters would be particularly useful for purification of air in such environments, both in hospitals and health care facilities, pharmaceutical companies, for example, in the preparation of medicines, ensuring biological safety and for the total removal of mold spores, fungi, and mildew from the air and liquid aerosols. Such filters would also be useful for collective protection and personal respirators, such as to protect soldiers from biological attacks, to protect against terrorist acts with the use of bacteria or viruses and/or when cleaning attacked places, such as the world Trade Center.

The invention

This invention represents a new filter or filter medium for the removal of substances in the form of particles in gaseous media that meets the needs in the high-performance filter with a high absorption capacity for the removal of substances in the form of microparticles, which inhibits pathogens and other substances in the form of microparticles air is a gas or threads including substances in the form of microparticles liquid aerosol, while maintaining low pressure drop. In accordance with this purpose of this invention is the provision of a filter which has at least the same high filtration efficiency that conventional HEPA filters, and which is resistant to clogging liquid aerosol.

Another goal in the exemplary embodiment of the present invention is the provision of a filter medium, which retains bacteria and viruses in the form of liquid aerosol.

Another goal in the embodiment of this invention is the production of air filter, which has a high porosity and is therefore more resistant to the adsorption of water mist compared to conventional filter media.

Another goal in the exemplary embodiment of the present invention is the provision of a filter medium, which has a filtration efficiency of at least as high as regular or Super ULPA ULPA filters.

Another goal in the exemplary embodiment of the present invention is the provision of a filter medium, which has a lower pressure drop compared to conventional filters.

Another goal in the exemplary embodiment of the present invention is predostavlyayutsya environment, which has the greater magnitude of pore size and higher porosity compared with HEPA filters, thus providing a higher absorption capacity for water droplets before flooding.

Another goal in the exemplary embodiment of the present invention is the provision of a filter medium, which has a low energy consumption.

Another goal in the exemplary embodiment of the present invention is the provision of a filter medium, which has a longer service life compared to conventional filters.

Another goal in the exemplary embodiment of the present invention is the provision of a filter medium, which ensures low operating costs.

Another goal in the exemplary embodiment of the present invention is the provision of a filter medium, which retains hazardous waste with minimal associated costs.

Another goal in the exemplary embodiment of the present invention is the provision of a filter medium that has sufficient strength so that it could be formed corrugated element.

Another goal in the exemplary embodiment of the present invention is the provision of a method of manufacturing a filter or filter medium, which filter the gaseous environment on the effectiveness Phil is ation, at least as high as that of conventional HEPA filters, and which is resistant to clogging liquid aerosol.

Another goal in the exemplary embodiment of the present invention is the provision of a method of using a filter or filter medium to remove substances in the form of solid particles and aerosols from gaseous media.

In General, this invention is a filter or filter medium for gases or gas mixtures. This filter medium contains nano-sized fibers of aluminum oxide, which absorb particles from the air or gas flow, and a variety of other fibers that are arranged in a matrix with nanoscale fibers of aluminum oxide with the formation of asymmetric pores. In one of the examples, the fibers include fibers, the minimum size of which is no longer small (smallest) size of nanoscale fibers of aluminum oxide is about an order of magnitude. Data other fibers included in nanoscale fibers of aluminum oxide to provide a basis for the formation of large pores or spaces between the fibers, in which or on which are dispersed nanosized fibers of aluminum oxide. In the examples of asymmetric pores have an average size greater than about 5 microns. In a preferred example, the average size of the pores extending t is more than about 10 microns. In a more preferred example, the average pore size is more than about 20 microns. In one example of this environment removes substances in the form of microparticles from the air or gas stream. In another example, this environment removes liquid aerosols from the air or gas stream.

Coarse fibers provide or form pores of larger size, in which or on which are dispersed nanosized fibers of aluminum oxide. However, coarse fibers have a smaller surface area per unit volume or mass, and therefore, the number of nano-sized aluminum oxide dispersed on or in the pores is significantly reduced. Therefore, in another embodiment, other fibers consist of coarse and fine fibers. The inclusion of thin fibers provides additional surface area, so more nano-fibers of aluminum oxide may be within a particular environment or on it.

In another embodiment, this invention is directed to a method of manufacturing a filter medium. This manufacturing method includes the following stages: formation of nano-sized fibers of aluminum oxide in the presence of many other fibers. Data other fibers are arranged with the formation of multiple asymmetric pores. In one example of the filter medium from nanolasers the first aluminum oxide to form a homogeneous filter medium as a typical surround filter. In another example, the filter medium of nanoscale aluminum oxide corrugate. In another example, the filter medium of nanoscale aluminum oxide is formed as multiple layers.

In another embodiment, this invention is directed to a method of use of the filter medium of nanoscale aluminum oxide to remove substances in the form of microparticles suspended in air or gas streams. In one example of the filter medium used to remove liquid and, in particular, water spray from a substance in the form of microparticles are suspended in pairs. This method of use includes the following steps: passing a gaseous medium through the filter medium, containing many nanofibers aluminum oxide, mixed with other fibers arranged in a matrix with the formation of multiple asymmetric pores between them; and the removal of substances in the form of particulate matter from a gaseous environment.

These and other features, objectives and advantages of this invention will be better understood or will become more apparent from the following description, examples and figures representing variations in its implementation.

Brief description of drawings

Figure 1 is a graphical representation of the velocity of flow of air through the filters of this invention and the nano-sized aluminum oxide and HEPA filter depending on the pressure drop across the filters.

Figure 2 is a graphical representation of the turbidity depending on the volume during filtration of latex spheres with a size of 0.2 μm, suspended in water, through the filters of this invention of nano-sized aluminum oxide and HEPA filter.

Figure 3 is a graphical representation of the magnitude of the transmission filter according to this invention of nano-sized aluminum oxide and HEPA filter with continuous passage through them of aerosols with NaCl particles 0.3 microns.

Figure 4 is a graphical representation of the resistance to flow of air filters for this invention of nano-sized aluminum oxide and HEPA filter during continuous passage through them of aerosols with NaCl particles 0.3 microns.

Figure 5 is a graphical representation of the flow speed of the air depending on the pressure drop through the filters of this invention of nano-sized aluminum oxide after pre-treatment of spherical latex particles of size 0.5 and 1 micron.

6 is a graphical representation of the magnitude of the transmission filter according to this invention of nano-sized aluminum oxide, pre-treated latex beads, as compared with the filter of nanoscale aluminum oxide without pre-treatment and HEPA filter by passing the aerosol NaCl 0.3 microns.

Fig.7 is grafy is a mini representation of the resistance to the flow of air filter according to this invention of nano-sized aluminum oxide, pretreated latex beads, as compared with the filter of nanoscale aluminum oxide without pre-treatment and HEPA filter.

Fig is a graphical representation of the transmittance of aerosols of NaCl 0.3 microns through the filters of this invention of nano-sized aluminum oxide and HEPA filter.

Figure 9 is a graphical representation of the resistance to flow of air filters for this invention of nano-sized aluminum oxide and HEPA filter when tested on absorptive capacity using NaCl aerosol.

Figure 10 is a graphical representation of the efficiency of the separation filter according to this invention of nano-sized aluminum oxide depending on the size of aerosol particles with KCl.

11 is a graphical representation of the antimicrobial action of filters according to this invention of nano-sized aluminum oxide impregnated with silver on bacterial proliferation.

Fig is a schematic depiction of the device used for testing filters according to this invention of nano-sized aluminum oxide using aerosols of bacteria that are transmitted through water.

Fig is a graphical representation of the relationship between differential pressure and pore size depending on the diameter of the fibers.

Fig PR is dstanley a comparison of pressure drop for filter media according to this invention of nano-sized aluminum oxide and sub-HEPA filter.

Detailed description

To the disclosure of the claimed invention was properly understood, described below, some used herein, the terms. Despite the fact that the applicants describe the following terms, they do not intend to abandon the ordinary and usual meaning of these terms.

The term "electrostatic", as used here, is defined as associated with electrical charges or related to them.

The term "aspect ratio", as used here, is defined as the ratio of fiber length and fiber diameter in cross section.

The term "nanoscale aluminum oxide", as used here, is defined as fibers with aspect ratio larger than about 5, for which the smallest dimension is less than about 50 nm. Cross-section of the fiber may be circular (cylindrical fiber) or rectangular (plate). Fibers formed from aluminum oxide with different content of bound water to form a composition predominantly formula AlOOH with different amount of Al(OH)3along with possible impurities gamma - and alpha-alumina.

The term " Lyocell", as used here, refers to fibers fibrillated cellulose precipitated from an organic solution in which no substitution hydroxylgroups, and not formed intermediate chemical compounds (Courtaulds, Ltd.).

The term "air filtration with high latency particle (HEPA) belongs to the class of filter medium, which can delay >99.97% of particles 0.3 microns.

The term "air filtering with a low pass particles" (ULPA) belongs to the class of filter medium, which can delay >99.99% of particles of a certain size at a given flow rate of the filtered substance.

The term "Super ULPA" belongs to the class of filter medium, which can delay >99.9999% particles of a certain size at a given flow rate of the filtered substance.

This invention provides a filter medium to remove particles, including liquid and, in particular, the particles of water in the form of an aerosol spray from an air or gas stream or other gaseous substances through a given filter medium to reduce air pollution and improve its quality. Examples of these particles are pathogens, such as bacteria, viruses, mold, fungi, mildew, organic matter, inorganic matter, microorganisms, carbon particles, fog fluids for metal working, mists of paints, pesticides, fogs paint or acid fog. In the examples of air or gas is the first stream contains micro-particles of a liquid spray, such as microparticles of a water spray. In one example of the filter medium is a non-woven electrisave environment. This filter medium contains nano-sized fibers of aluminum oxide, mixed with other fibers. In one of the examples of nano-sized particles of aluminum oxide are non-spherical. Data other fibers are arranged in a matrix with the formation of asymmetric pores. In one example of the fine powder of aluminum metal reacts with other fibers to form elektrischem environment. The reaction is carried out by adding ammonia to the mixture of aluminum and other fibers. The mixture is heated to the boiling point of water. In another example, trihydroxide aluminum is heated under high temperature and pressure in the presence of other fibers to form elektrischem environment. This reaction is carried out at about 175°C and about 5 bar for about thirty minutes.

Other fibers may be fibers that are durable enough to withstand shirring, including glass fibers, fibrillated cellulose or cellulose. In one of the examples of other fibers have a minimum size, which is larger than the small size of nanoscale fibers of aluminum oxide at least about an order of magnitude. In the examples, the average pore size is in the interval for the Les from about 4 to about 48 microns. Preferably the average pore size is more than about 10 microns. More preferably, the average pore size is more than about 20 microns. Typically, the pore size is correlated with the diameter of the other fibers. So many other fibers having a small diameter, will create many asymmetric pores having small dimensions, while many other fibers having a larger diameter, will create many asymmetric pores having a size relatively larger magnitudes. See, for example, Table 1 and Fig. However, when increasing the diameter of the other fibers, the amount of surface area per unit volume decreases, and as a result less of nanoscale fibers of aluminum oxide dispersed on other fibers and/or in the pores. Therefore, in preferred examples, many other fibers includes a combination of a variety of coarse and many fine fibers. Thin fibers can have all basically the same average diameter, or some thin fibers can have other diameters. The inclusion of thin fibers leads to a corresponding reduction of pore size. See, for example, Table 1 and Fig.

The pore size determines the pressure drop across the filter medium. In a preferred example, the differential pressure is less than about 35 mm H2O for the composite filter of thin cleaning cloth and or filter node at a flow rate of approximately 3.2 m/min

In one example of the filtering medium according to this invention also contains granular sorbent, preferably colloidal particles, which added to the filter medium. For adsorption of volatile organic compounds, nerve gas or mustard add granulated activated carbon in the form of fine powder (for example, in the form of coal dust with a particle size of from 3 to 5 microns)to ensure faster absorption compared to conventional granular carbon with particles of larger size. In another example, may be added to the granular oxide or hydroxide of iron, preferably of colloidal size, in order to improve the adsorption of dissolved Arseniev and Arsenates. Also to the nanoscale aluminum oxide can be added such granular material, as fine silica or iron oxide to further improve the performance of filter media for General applications in order to remove substances in the form of particles.

In one example of the filtering medium according to this invention also contains a binder. A binder may be in the form of fibers (Invista T 104) or may be a resin such as Rohm or Haas Rhoplex HA-16. The inclusion of binder increases the strength of the fibrous medium and/or its ability to shirring.

In one example filtrowa the environment may also contain an antimicrobial agent, which is mixed with many nanoscale fibers of aluminum oxide and other fibers. In the manufacturing process after the preparation of the suspension before filtration of the mixture on a sieve add an antimicrobial agent and adsorb it on nanoscale fibers of aluminum oxide to ensure its action as antimicrobial agents. In one of the examples of the antimicrobial agent is silver. In other examples, ions, e.g. copper and zinc act in a synergistic manner with the silver as an antimicrobial agent. In another example, ions of, for example, copper and zinc are separate way as an antimicrobial agent.

In one of the examples of the present invention the filter medium is electrostatically charged, so that the nano-fibers of aluminum oxide capture particles such as pathogens and other substances. In one example of the filter medium is a filter from a uniform non-woven material. In other examples, the filter medium Gavrilovna to increase the surface area of the filter medium at about 7-10 times than not filtering medium. The increased surface area of the filter medium reduces the flow rate through the filter, which greatly improves the efficiency of the awn filtering. The increased surface area also provides a higher absorptive capacity to filter particles, resulting in an increasing period of time to increase the differential pressure.

In another example, the filter medium layer or stack in the foot, for example, by winding the environment around a perforated support, to improve latency. The need for the formation of multilayer structures may occur when the pore size is more than about 25 microns.

In one example of the filter medium pre-treated or pre-prepare the transmission through it of many particles. The particles can have a diameter in the range of from about 0.3 to about 1.5 microns. The inclusion of these particles will block at least some of the pores of the maximum value from the set of asymmetric pores to reduce the initial leakage through the filter medium. In addition, pre-treatment facilitates the provision of, or the potential of HEPA or ULPA when using the filter. In one example of the multitude of particles is a set of latex spheres, although this many particles can be made of any substance that is capable of blocking at least part of the pores of the maximum value.

In Odemis examples of filter medium according to this invention of nano-sized aluminum oxide has at least the same efficiency delay, as HEPA. In another example, the filter medium according to this invention has at least the same high efficiency delay that and ULPA.

In another embodiment, the invention is a method of manufacturing a filter of nanoscale aluminum oxide to gaseous media. This manufacturing method includes a stage of formation of nanoscale fibers of aluminum oxide in the presence of many other fibers. Data other fibers are arranged with the formation of multiple asymmetric pores. In one example of the filter medium of nanoscale aluminum oxide to form a homogeneous single sheet. In another example, the filter medium of nanoscale aluminum oxide is formed as multiple layers. In another example, the filter medium of nanoscale aluminum oxide corrugate.

This filter medium can be used in a filtration system. When using air or gas stream is passed through the filter medium and removed from the material in the form of microparticles by delaying particulate filtering medium. In one of the examples of the gaseous medium contains a suspension of fine droplets of water. Examples of the use of such a filter include, but are not limited to, use to filter the air in the room, used the e in respirators or face masks, use in automotive air filters, use in clean rooms, operating or use in an industrial environment, for example, removal of paint and varnish materials or other substances in the form of microparticles contained in the industrial fog. In one example of the filter medium used in an environment that has a relative humidity of more than about 75%.

Examples of the present invention

The examples below illustrate several embodiments of the present invention. These examples should not be construed as limitations. All values are percentages stated by weight. Calculations to determine the size of the pores provided in the discussion following Examples 1-10.

Example 1

The goal of the experiments described below were receiving environment of nanoscale aluminum oxide, which provides basically the same pressure drop for the environment HEPA, and the filtration efficiency is higher than compared to HEPA. The aim of the experiments was also the establishment of the balance characteristics of the adsorption of water between the filtering medium of nanoscale aluminum oxide and known filter media HEPA (hereinafter "HEPA filter Donaldson"), to optimize the air filtration when using the AI data on adsorption from water.

Twenty-four suspensions of mixtures of nanosized aluminum oxide microparticles glass reaction produced by the interaction of aluminum powder with a particle diameter of 5 μm (Valimet Corp. # H-5) in water at 100°C in the presence of fibers made of borosilicate glass disordered length (Lauscha). Environment of non-woven fibres, containing nanosized alumina, was formed on the sheet-shaped 1x1 ft and was secured by adding 17-23% bicomponent fibers (Invista T104, with a diameter of 20 μm, a length of 1/2 inch), which served as a binder. Also added binder Rhoplex in an amount of about 2% by weight in liquid form. The obtained sheets were designated as AFl - AF24.

The filters were tested as single layers when using the air flow speed in the range of from about 5.6 to about 23 m/min, the filters were compared with water filter NanoCeram® and HEPA filter Donaldson, in order to compare the characteristics of air or gas filter according to this invention of nano-sized aluminum oxide with a water filter and a conventional HEPA filter.

Table 1 presents the composition, porosity, pressure drop and average pore size for each of the manufactured sheets and environments NanoCeram and HEPA. Fig also shows the pore size and the pressure drop for some filters, nano-alumina, which have been tested. Ka is the Mae of the filter media, presented in Table 1 and Fig was tested in the environment of a single layer. However, when using operating characteristics can be improved by layering multiple layers as described above and as shown in the examples below.

As shown in Table 1, the filters AF1-AF12 included nanofibres aluminum oxide, mixed with glass microfibers, the diameter of which was for different filters about 0.6 μm, about 1.5 μm, or about 2.5 μm. Filters AF13-AF24 included nanofibres aluminum oxide, mixed with the following combinations of coarse and fine glass microfibers: about 0.6 μm + about 1.5 μm, about 0.6 μm + about 2.5 microns, or about 1.5 μm + about 2.5 μm. The percentage of fibers of each size in the respective filter medium of nanoscale aluminum oxide are listed in Table 1.

13,0
Table 1
The composition and properties of the test filters
of nano-sized aluminum oxide
Table of contents
nano-sized-
those fibers
oxide
aluminum
%
Table of contents
DoCoMo-
being input
fibers/a-
lulose,
%/%
Table of contents
glass
microfono-
Kohn, %
Diameter
glass
microfono-
con, mcm
The main mass, g/m2Paris-
lead,
share
ΔP air at 3.2 m/min mm H2OThe average pore size (EQ. [3]), microns
NanoCeram3513/21310,61600,88130the 3.8
AF1the 3.824/072,21,51560,9310,419
AF211,722/0to 66.31,51700,9212,317
AF32020/0601,51780,9116
AF4the 3.824/072,22,51550,954,135
AF57,723/069,32,51500,964,037
AF611,722/0to 66.32,51600,964,338
AF77,723/069,30,61640,921255,2
AF82020/0600,61980,90/td> 1514,8
AF933,316,7/0500,62400,882044,2
AF1011,722/13,3531,51640,9310,421
AF117,723/13,955,42,51440,943,437
AF122020/12480,61780,901345,1
AF1311,722/016,6
49,7
0,6
1,5
1620,9234,010
AF1411,722/033,2
33,1
0,6
1,5
1680,9195the 5.7
AF1511,722/049,7
16,6
0,6
1,5
1720,90105of 5.4
AF167,723/017,3
52
1,5
2,5
1600,94the 5.728
AF177,723/034,6
34,6
1,5
2,5
1540,947,624
AF187,723/0 52
the 17.3
1,5
2,5
1600,949,222
AF197,723/017,3
52
0,6
2,5
1680,9216,614
AF207,723/034,6
34,6
0,6
2,5
1580,9046,68,7
AF217,723/052
the 17.3
0,6
2,5
1580,9175,56,4
AF2211,722/13,326,5
26,5
0,6
1,5
1680,9248,28,8
AF23 7,723/13,927,7
27,7
1,5
2,5
1460,936,725
AF247,723/13,926,5
26,5
0,6
2,5
1560,9043,38,5
NERANANANANA480,8415,56,0
Note: NA - not applicable

The ratio between the diameter of the glass microfibers and

the porosity of the environment

The data presented in Table 1 show that the environment containing glass fibers of small diameter, also had a more low porosity and small pore size. These ratios are also illustrated in Fig. For example, the environment containing glass microfiber size of 0.6 μm, had a porosity of about 90% and a pore size in the range from 2 to 10 μm. Environment containing glass microfiber size of 1.5 μm, had a porosity of about 92.3% and a pore size in the range of from about 16 to about 21 microns. In conclusion, the environment containing glass microfiber size 2.5 μm, had a porosity of about 95.3 per cent and the pore size in the range of from about 35 to 38 microns.

The data presented in Table 1 and Fig also show that environment, having the largest pore size or porosity, also had the lowest pressure drop. For example, environment, having a porosity of approximately 95%had a pressure from about 3.4 to about 4.3 mm H2O, unlike the pressure drops from about 125 to about 204 mm H2O for a porosity of about 90%.

In the examples, in which the filter medium contained a combination of coarse and fine fibers, the pore size has not increased in such a significant way as it took place in the presence of only one coarse fibers. See, for example, Table 1 and Fig. For example, fiber size 2.5 μm, combined with a fiber size of 1.5 μm, have a pore size in the range of from about 22-28 μm and a porosity of about 94% with a corresponding pressure drop of from about 5.7 to about 9.2 mm H2O.

It is noticeable that most of the samples AF1-AF24 had a pore size greater than the HEPA filter Donaldson. For example, AF6 had a pore size which is more than six times previsualizar then HEPA filter Donaldson.

Filtering characteristics of the air flow

Filters from the group of test filters AF1-AF24 divided on the basis of their ability to the passing air stream. Data for filters with a pressure drop less than 10 mm H2O at 3.2 m/min is shown in figure 1. The solid line corresponds to the flow velocity of 3.2 m/min These results indicate that there are several variations of material composition according to this invention of the fibers on the basis of nano-sized aluminum oxide, which have a lower pressure drop compared with HEPA filters. These results are believed to be caused by the greater magnitude of the pore size data of new filter media.

Evaluation of filter substances in the form of microparticles at

using tests with monodisperse latex

Usually for modeling liquid aerosols used oil aerosols, for example, dioctylphthalate (DOP), and aerosols of sodium chloride (NaCl) or potassium (KCl) is used for simulation of solid particles in evaluating materials for air filtration. Applicants have compared the adsorption of ultrathin monodisperse latex spheres in water with their adsorption HEPA filters and then tried to establish a correlation with the data obtained in tests with DOP and NaCl. Namely, air filters AF3 (average pore size of 16 μm, see Table 1), AF6 (average pore size of 38 μm, see Tables is 1) and HEPA filter Donaldson, having a diameter of about 25 mm and an effective surface area of approximately 3.7 cm2experienced in the use of the fluid flow from the pure (RO) water with latex spheres with a size of 1 μm at a constant flow rate of about 0.1 m/min Despite the fact that Table 1 presents the filter medium placed in a single layer, in this experiment consisted of the foot from one to four layers in order to optimize operating characteristics of the filter media in applications for air and water. The turbidity of the input and output flows (in NTU values or units turbidity) of water was measured using turbidimetry LaMotte model 2020.

Figure 2 shows a plot of turbidity flow at the output of filters containing nanoscale fibers of aluminum oxide and glass microfiber, compared to conventional HEPA filter. As can be seen from Figure 2, the filters according to this invention, containing nanosized fibers of aluminum oxide and glass microfiber, provide almost undetectable turbidity output compared with HEPA filter.

The results of this experiment are unexpected, because the filters according to this invention were detained particle size of 0.2 μm even in the case of filters, AF3 and AF16 having an average pore size of about 16 and 38 μm, respectively. Expected covertry with such a large average pore size will not be able to hold particles of much smaller size. Very bad delay HEPA filter in aqueous media was also unexpected, indicating that HEPA filters have much less delay in water compared to air and, therefore, behave differently in these two environments.

The objective correlation data on adsorption from water characteristics for air was not successfully achieved, and therefore, subsequent experiments were conducted to obtain data when testing air filters.

Examples 2-10

In examples 2-10 filtering medium of nanoscale aluminum oxide, denoted as AF3, AF6, AF11 and AF16 used for further characterization of filter media according to this invention of nano-sized aluminum oxide in comparison with HEPA filter Donaldson. As shown in Table 1, AF3 contained glass microfiber size of 1.5 μm, AF6 and AF11 contained glass microfiber size 2.5 μm, and AF16 contain a combination of glass microfibers 1.5 and 2.5 microns.

Example 2

The initial transmission of particles DOP and NaCl

Filters AF3 (average pore size 16 μm), AF6 (average pore size 38 μm), AF11 (average pore size of 37 μm) and AF16 (average pore size of 28 μm)manufactured in Example 1, and the HEPA filter was sent to Nelson Laboratories in salt lake city, Utah, for testing with the use of aerosol particles DOP and neutralized monodisperse what's the NaCl particles. Concentration in the tests was 1.5·106particles/cm3at a flow rate of 32 l/min through the filter area of 100 cm2. Aerosols had an average particle size of 0.3 μm, which was regarded as being in the range of sizes, the most capable of transmission. Test samples were prepared in the form of squares 10x10 cm or discs with a diameter of about 4-5 inches. Three layers of flat sheets or three-layer flat sheets pinched on the test device and felt a stream of air at a flow rate of 32 l/min the Results are presented in Table 2.

Table 2
The initial transmission DOP and NaCl
SampleThe number of layersDOP/NaClInitial resistance to the flow of air
(mm H2O)
Transmission of particles
%
HEPA1DOP32,80,02
NaCl32,80,025
AF163DOP 29,10,513
NaCl32,10,323
AF64DOP23,41,27
NaCl23,60,755
AF114DOP19,52,72
NaCl19,41,60
AF31DOPof 21.24,12
NaCl21,32,61

Filter AF 16 had the lowest initial transmittance of aerosol NaCl and DOP, even though this transmission was incomparable with the transmission of HEPA filter. This sample was formed from a mixture of glass microfibers 1.5 and 2.5 microns and contained only 7.7% of nano-sized aluminum oxide. He had a pore size of about 28 microns. These results show that most of the structures of nanoscale OK the IDA aluminum had the original transmission is higher than in the technical requirements for HEPA.

Example 3

Testing absorptive capacity for NaCl aerosol

Filters AF3, AF6, AF11 and AF16 and HEPA filter (test area of 100 cm2experienced with the use of NaCl aerosol at a flow rate of 32 liters/min for about 3 hours each. About 0,0067 mg/min/cm2NaCl was applied to each filter, which is equivalent to about 40 mg/h As described above, you usually had three layers AF16 (1.2 mm each, a total of 3.6 mm)to achieve the same pressure drop as for HEPA, so the testing was performed using three layers in comparison with HEPA.

Figure 3 shows the graphs of the transmission values of each of the filters used in the test aerosols of NaCl, depending on time. It is seen that the filter AF16 had the lowest initial transmission of NaCl aerosol, but it was still significantly higher than for HEPA. AF16 had the lowest initial transmission and was therefore used for subsequent evaluations performance.

Absorption

Figure 4 shows the graphs of the resistance to flow of air filters depending on time. Absorption capacity (or the life of the filter in this example was defined as the time (minutes)required to reach a pressure drop (ΔP) in 50 mm H2O. As shown in figure 4,all the filters according to this invention of nano-sized aluminum oxide, used for testing had the absorptive capacity, which is at least ten times higher than its value for the HEPA filter. Filters AF6 and AF11 had a value of absorptive capacity, which exceeded the absorptive capacity HEPA approximately 30 times. These results are important because the life of the filter is usually determined in accordance with a given limiting magnitude of the pressure drop across the filter. The increasing pressure to achieve a given level limits the service life for this type of application or design. Due to the fact that the increased pressure is caused by clogging of the filter, for systems with equal efficiency, longer service life is usually associated directly with higher absorptive capacity. Efficiency represents the tendency of the environment to a greater extent to the capture substance in the form of particles, than to his passing. Usually, the more effective filtering medium to remove substances in the form of particles from the gas stream, however, as a rule, faster filter medium reaches a pressure difference corresponding to the end-of-life, assuming that other parameters are kept at a constant level.

Filter having a high absorptive capacity, much more profitable, as it allows to decrease the giving of the cost of frequent replacement of the filter. In addition, many filters, including those that trap bacteria and viruses or materials for nuclear reactors, should be eliminated as hazardous waste. Therefore, reducing the frequency with which the filters are hazardous waste and must be replaced and eliminated an additional economic advantage.

Table 3 presents the results of the tests with NaCl aerosol at speeds of flow of the air flow approximately 3.2 m/min for the filters disclosed in U.S. Patent No. 6872431, Kohlbaugh, ("patent '431"), and fibers according to this invention, containing nanosized fibers of aluminum oxide and glass microfibre level "pre-HEPA filter to remove particles of 0.3, while the "pre-HEPA" is defined as the effectiveness of the medium in the range of from about 98.9 per cent to about 99.6 percent. Table 3 also presents the test results of one of the filters according to this invention (single-layer filter AF16) when the particle size neutralized KCl corresponding to the largest penetration and average of 0.33-0.40 micron, when the velocity of flow of about 4.6 m/min

Table 3
Transmission of NaCl aerosol (0.3 microns)
for the test sample level "pre-HEPA"b
Wednesday The initial
transmission of particles
%
The number of layersThe effectiveness of
one layer
%
Thickness,
mm
Time to 125 mm H2O
min
Time to 50 mm H2O
min
US 68724310,6and10400,54b<170c<80c
US 68724310,4d14280,75b<230c<125c
US 68724310,4a25201,4b,e<260c<170c
AF60,76480f1,8320f160
AF16 1,1g198,9g1,2170f100f
Notes: (a) this is an estimated value based on the equations presented in the description of the patent '431, pages 23 -24; (b) it estimates, based on data presented in the patent '431, page 35, lines 1-10; (c) this is an estimated value based on the data presented in the patent '431, page 43; (d) this is an estimated value based on the data presented in the patent '431, page 39; (e) the estimated thickness exceeds the limit for the structure of the filter medium (see item 14 of the patent claims '431); (f) this is an estimated value; (g) this filter was tested using particles neutralized KCl, the size of which corresponds to the greatest penetration and ranges from about 0.33 to about 0.40 micron when the velocity of flow of about 4.6 m/min

The results presented in Table 3 show that at the level of "pre-HEPA":

1. Wednesday AF6, which is capable of shirring, has a higher absorptive capacity before reaching the pressure drop of approximately 125 mm H2O and about 50 mm H2O compared with the medium as disclosed in patent '431 containing 10, 14 or 25 layers life expectancy at 125 and 50 mm H 2O increased by approximately 40%, 28% and 20%, respectively.

2. Single layer environment AF16 has an expected service life and the efficiency of removal of particles with the highest penetration (KCl, 0,33-0.4 µm)that exceed their value to filter disclosed in patent '431, in the form of structures of 10 and 14 layers.

These data are important because they show that fibrous environment of nanoscale aluminum oxide have increased life expectancy compared to filter by patent '431, and the removal efficiency of particles is higher than that of the filter patent '431. Thus, the filters according to this invention of nano-sized aluminum oxide not only more profitable, but they also have superior performance. In addition, it is much cheaper to make the environment one type than the environment 10-14 different layers, and, in addition, in the latter case, attention should be given to prevent delamination.

Table 4 presents the results of the tests with NaCl aerosol with air velocity of about 3.2 m/min for filter disclosed in patent '431, and fibers according to this invention, containing nanosized fibers of aluminum oxide and glass microfibre level "pre-HEPA" in the case of removing particles 0.3 microns.

Table 4
Results the ATA test with NaCl aerosol at the level of HEPA
WednesdayThe effectiveness of patterns,
%
The number of layersThe efficiency of a single layer,
%
Thickness,
mm
Time to 125 mm H2O,
min
Time to 50 mm H2O,
min
US 687243199,97a16400,89b<170c<80c
US 687243199,97a25281,4b<230c<125c
AF699,97d580d1,8300d140d
AF1199,976d675d2,5310d120
Donaldson
HEPA
99,975199,9750,2243,5
Notes: (a) these estimates are based on equations presented in the description of the patent '431, pages 23-24; (b) it estimates, based on data presented in the patent '431, page 35, lines 1-10 (it should be noted that this estimated thickness exceeds the limit for the structure of the filter medium, see paragraph 14 of the claims of the patent '431); (c) this is an estimated value based on the data presented in the patent '431, page 39, lines 39-45; (d) this is an estimated value.

The data presented in Table 4 show that the environment AF6 and AF11 have higher values of absorptive capacity before reaching the differential pressure of 125 or 50 mm H2O compared with the medium as disclosed in patent '431, which has 16 or 25 layers. Environment in this invention increase the expected service life of the filter by at least 80% before reaching the boundary pressure 125 mm H2O compared to the environment in patent '431, although the environment in patent '431, including 25 layers, has a comparable life expectancy to a pressure drop in 50 mm H2O.

Note the p 4

Pre-processing

The purpose of this example was the removal of the initial leakage when tested according to the conditions for HEPA. It was assumed that the initial infiltration is associated with the largest pore size in the filter media (which contain pores in a wide range of sizes due to the asymmetric arrangement of fibers). It was also assumed that the injection of foreign particles in the filter, to prepare the filter before use, would cause the flowing particles in the pores of the longest dimension, blocking them, thereby reducing the initial infiltration with a corresponding improvement in the efficiency of the filter.

To test this assumption in the filters previously filed modifying agent so that these pores were plugged before use. In this test used the sample AF16 (filter diameter 25 mm). For the preparation of filters used monodisperse latex spheres (Duke Scientific), because these areas are stable in air and does not change in a wet air stream. The experiments were conducted using latex spheres with a diameter of 0.2, 0.5 or 1 μm. Areas served in the filter and measured the resistance to flow of air.

Resistance to air flow was measured as described above. Pre-feed areas of 0.2 μm was provided mini is material effect on the pressure drop in the filters of this invention (data not shown), and after some preliminary feed turbidity output had measurable value.

Figure 5 presents a graphical view of the flow velocity of air and the change of pressure drop after pretreatment in filters according to this invention of latex spheres (0.5 or 1 μm. During the introduction it was noted that the turbidity of the output stream was below the limit of sensitivity of 0.01 NTU, which involves quantitative adsorption of these particles increased the size of the filtering medium. These data indicate that latex spheres with a size of 0.5 and 1 μm are suitable for pre-treatment filters spheres.

Thus, the results of Example 4 show the following.

1. Foreign particles, such as monodisperse particles can be used to prepare the filter medium of nanoscale aluminum oxide.

2. The turbidity measurement during the preliminary injection is an effective method of monitoring and controlling the process of pre-injection.

3. In the samples can be pre-introduced latex beads (0.5 and 1 μm to display the differential pressure (ΔP), which takes place during testing of NaCl aerosol.

4. Latex particle size of 0.2 μm are too small to achieve the desired ΔP.

As al is ternative expensive latex particles for pre-processing filters can be used cheaper particles, preferably submicron dimensions, including, for example, ultrathin granular carbon agglomerates of finely dispersed silica (Cab-O-Sil) or metal oxides.

Example 5

Testing pretreated samples AF16

transmission and absorptive capacity in relation to NaCl

Test samples were prepared prior to submission of latex spheres with a size of 0.5 μm on one side of the filter, consisting of 3 layers of protection AF16. This environment was used in the form of a circular disk size 175 cm2. Samples (test area of 100 cm2experienced (Nelson Laboratories) using a NaCl aerosol at a flow rate of 32 liters/min for about 3 hours each. The approximate weight of NaCl, which was supplied to the filter was 0,0067 mg/min/cm2or 40 mg/h or 0.5%/h in the calculation of the mass of the open part of the filter. At a flow rate of 32 liters/min speed was 3.2 m/min, the thickness of the filter of three layers AF16 was about to 0.36 cm, which resulted in a calculated residence time of approximately 0,07 C.

Figure 6 presents a graphical view of the resistance to the flow of air filters with nano-sized aluminum oxide, pre-treated latex spheres, when applying NaCl. It is seen that during the 3 hours of testing the resistance to the flow of air all tested samples of nano-sized, the second aluminum oxide was much lower than HEPA. The HEPA filter has reached ΔP 50 mm H2O about 4 minutes, while the samples of nano-sized aluminum oxide was required about 40 minutes to reach the same value ΔP (one of the filters of nanoscale aluminum oxide, which contained 9 wt.% latex, reached ΔP 50 mm H2O approximately 30 minutes). This increase service life of the filter, which is about 7-10 times greater than for HEPA is an advantage for applications that use high-efficiency filters, including hospitals, collective protection equipment for military purposes, the funds relating to national security, cars and respirators.

Figure 7 presents a graphical view of the transmission filters with nano-sized aluminum oxide, pre-treated latex beads. Although the original transmission was not reduced to 0.03%, the delay is increased when the continuous supply of NaCl particles. All pretreated samples AF16 had lower initial transmission NaCl compared to the original AF16. There is a trend of improved performance with increased pre-filing latex spheres with a size of 0.5 μm, with the least amount of bandwidth 0,047% to 9 wt.% latex in comparison with the transmission of 0.03%set for HEPA.

Example 6

Filter among the s experienced in relation to delay of NaCl aerosol at Nelson Laboratories, analogously to Example 2. On Fig presents graphically the transmission of NaCl aerosol with a particle size of 0.3 microns through the subjects environment. In this example, compare the following examples: HEPA; single layer AF16 without prior introduction, which was used as a pre-filter for HEPA filter; and three layer AF16, pretreated latex particles. As can be seen from Fig, only one HEPA filter cannot function as a ULPA. In contrast, pre-treated filter AF16 had initial and ongoing delay >to 99.99%, which allowed it to carry ULPA filter. In addition, as shown in Fig, add a single layer AF16 (without preprocessing) as a pre-filter for HEPA also leads to achievement level ULPA. These data show that the filtering medium according to this invention of nano-sized aluminum oxide has a delay greater than its value to conventional HEPA filters, such as HEPA filter Donaldson, and use of nano-sized aluminum oxide as a pre-filter improves the characteristics of HEPA to the level of the ULPA.

Figure 9 presents a graphical view of the resistance to the flow of air test filters in testing the ability to absorb NaCl aerosol samples described above. Adding single the layer AF16 without pre-treatment increases the life of the HEPA filter by about 700%, before reaching the threshold ΔP 50 mm, which leads to considerable savings in practical use.

Thus, the filters according to this invention are more effective in delaying particles and have a longer expected service life than conventional HEPA filters, and therefore, these filter media according to this invention of nano-sized aluminum oxide are more profitable.

Example 7

Examples of environment AF16 was tested by LMS Technologies, Inc. (Edina, Minnesota) according to the norm 319 protection Agency U.S. environmental protection Agency (EPA), which determines the measurement of characteristics of filtration systems to remove excess powder paint material in the aerospace industry. In the United States in the finishing operations performed in industry, 30% of the sprayed paint material, what is the value of 90 million gallons sprayed into surplus, much of which is dissipated in the atmosphere.

One layer environment AF16 felt when the velocity of 15 ft/min Initial pressure drop was 22 mm H2O. figure 10 presents in graphical form the delay or separation efficiency test filter depending on the particle size. These same data are presented in Table 5.

This filter also compared with available the sale of sub-HEPA filter (Trinitex K903-70, production Ahlstrom). On Fig compares the pressure drop across the filter Trinitex and filter AF16. As you can see, the differential pressure on both filters are very similar. It is essential that the delay for AF16 was significantly higher compared with the technical requirements of the EPA, as well as compared with the medium Ahlstrom for all particle sizes in the comparison interval. The results show that this new environment can significantly improve the performance characteristics of the media sub-HEPA without the need for pre-processing.

Table 5
Delay KCl aerosols based
the size of the particles
Size range, micronsInitial delay for a single layer of filtering medium aluminum oxide AF16, %Technical requirements EPA 319Ahlstrom Trinitex
0,33-0,4098,92352%
0,40-0,5099,365>75%59%
0,50-0,6099,74363%
0,60-0,8099,989>85%68%
0,80-1,0099,95574%
1,00-1,5099,98390%
1,50-2,0099,995>95%95%

Example 8

Simultaneously examined patent application directed to the use of silver to control bacterial proliferation. So, there was tested the inclusion of silver in the environment for air filtration. Three sheets of nano-sized aluminum oxide were prepared from powder of aluminum, as described for sample HF0404 in Example 1, except that the silver nitrate with 0.1%, 0.3% and 1 wt.% based on the silver content in the solids of the suspension) was added to the suspension. Samples (25 mm diameter) were placed in the filter holder and introduced into 10 ml suspension of Klebsiella terrigena at a concentration of 8·107CFU/ml (colony forming units per ml) in buffered aqueous solution. Bacteria were suirable of the filters in the opposite direction when using 3 ml of a solution containing 3% matnog the extract and 0.35% solution of glycine at pH 7.5, immediately after injection and then after exposure for 1, 5 and 18 hours. Figure 11 presents in graphical form the antimicrobial action of ionic silver, included in nanoscale fibers of aluminum oxide, depending on the time spent on the filter. You can see that the filters of nanosized alumina, impregnated with silver, control bacterial proliferation with increasing degree of control by increasing the content of silver nitrate.

The tests also showed that when the content of 1% silver no noticeable effect on the filtration of the virus MS2; this indicates that the efficiency of the filter medium against viruses does not change after adsorption of 1% silver.

These results show that the addition of silver nitrate in the filter minimizes any secondary entrainment of bacteria or viruses from the filter, because it acts as an antimicrobial agent. Leaching of silver from the impregnated filters was approximately 30 µg/l, which is significantly below the value of 100 µg/l, required in accordance with EPA for drinking water. After use, the filter may be disposed of as household waste, rather than as hazardous waste with the high cost of liquidation.

Example 9

Testing of samples of the environment bacterial aerosol

E. Coli

D. the I tests were collecting device, originally developed by Henderson [1], and have tested using E. coli bacteria. In this device, scheme is presented on Fig, 5 ml suspension of E. coli in 1,4·109CFU/ml in buffer solution was sprayed by a spray gun DeVilbiss PulmoMate (model SR4650D). The second spray was driven with an equal amount of buffer solution. Educated aerosols have injectively in a pipe with a diameter of 5 cm and a length of 90 cm Relative humidity was regulated by the mixing of the air, which passed through the hydrating and moisture-absorbing branches of conditioning, before the introduction of the spray pipe. Relative humidity and temperature of the air near the end of the pipe was measured by a moisture meter. About 1/3 of the flow from the outlet of the aerosol tube was passed through impinger AGI-30. The rest of the thread was passed through a pipeline with an inner diameter of 12 mm and then was merged with the air, passed through impinger. The air flow then passes through the HEPA filter (Whatman, PolyVent-1000 Cat #6713-1075).

Total consumption was 38 liters of air per minute. Two spray created the air flow 12 l/min (6 l/min each) and air flow with a flow rate 26 l/min was applied by an air compressor. The flow of air through impinger was 12 l/min

Filter efficiency was calculated as:

Efficiency, % = [(Concentration the walkie-talkie E. coli in the upper reaches of the Concentration of E. coli in the lower reaches) x 100%]/Concentration of E. coli in the upper reaches [1],

where the concentration of E. coli in the upper reaches was determined without a filter in the air flow with the included E. coli, and the concentration of E. coli in the lower reaches were determined with the filter in the air flow with the included E. coli at a relative humidity equal to or close to 100%.

In the first experiment, three layers of filter media, AF16 (without pre-treatment particles) were placed in the filter holder with a diameter of 90 mm In the second experiment, a single layer Donaldson HEPA placed in the same filter holder. As shown in Table 6, the filter medium AF16 had a latency of bacteria, which was about 50 times greater than that of the HEPA filter.

Table 6
Efficiency (%) filter with nano-sized aluminum oxide when tested with bacterial aerosol E. coli (Conditions:
32 l/min, relative humidity 100%, temperature of 23.9°C)
Filter mediumThickness, mm (the number of layers x thickness)The average pore size *, mmFilter/
Without filter
The number of E. coli bacteria are defined in the buffer solution AGI-30, CFU/td> The effective delay of E. coli,
%
AF163,6
(=3 x 1.2)
28Filter<1>99,9998
Without filter5,9·105
AF67,2
(=4 x 1.8)
38Filter<4>99,9992
Without filter5.2 x 105
AF30,9
(=1 x 0,9)
16Filter<4>99,9992
Without filter5.2 x 105
AF111,3
(=1 x 1.3)
37Filter499,994
Without filter6,7·10 4
Donaldson HEPA0,4
(=1 x 0,4)
6Filter4099,992
Without filter5·105
* Data from Table 1

Each sample AF had a pore size substantially greater than the pore size of conventional air HEPA filter. As is known, a filter with a larger pore size of the environment is less prone to clogging. This clogging resistance may also be able to filter by this invention to be less resistant to ponding water droplets.

Demonstrated ability nanofiber alumina to remove bacteria at high levels of delay was an unexpected result and is a major advantage, particularly where the filter is used for collective protection, for example, in the hospital, which treats patients with a weakened immune system, or for protection when hostilities with the use of biological weapons. Such an environment would also be useful in improved respiratory filters to improve the delay of bacteria. Other mainly what westom is lower differential pressure according to this invention in comparison with HEPA, especially as the filling of the filter. Finally, another advantage is that the pore size of the filtering medium of nanoscale aluminum oxide is much larger, which leads to significantly increased porosity of the filter, providing hold much more water when the continuous supply of water droplets or mist.

Example 10

Two experiments were performed as described in Example 9, except that the aerosol contained a virus MS2 (25 nm), and the test was carried out at two different values of relative humidity. In this case, the tested samples had a small pore size (~2 μm) and had a thickness of 0.4 mm

/tr>
Table 7
Efficiency (%) filter with nano
aluminum oxide relative to the aerosol virus MS2
Relatively
Naya RH
ness, %
Test
the oxygen-
the acidity,
PFU/mla
Filter/
without filter
Number
viruses MS2,
a certain
in the buffer
the solution AGI-30,
PFU
Limit
detection
of PFU/ml
The effectiveness of
collection MS2
impingere, %
The effectiveness of
delay MS2,
%
942,6·107Filterb<150100Not applicable>of 99.96
Without filterc4,2·1051002,1
601,3·107Filterd<11Not applicable>99,999
Without filtere1,1·1051001,3
Notes: a) 2 ml of MS2 test solution was converted into an aerosol;
b) the test Time is 6 minutes; the collected amount of a solution of virus - 1.5 ml;
c) the test Time is 10 minutes; the collected amount of a solution of virus - 2.2 ml;
d) the test Time is 6 minutes; the collected amount of a solution of virus - 1.0 ml;
e) the test Time is 6 minutes; the collected volume of virus solution and 1.5 ml

The data of Table 7 show that the filter has a high EF is aktivnosti collection of aerosols, containing the virus. These results are important because the viruses that typically one or two orders of magnitude smaller than bacteria, it is very difficult linger volumetric filtering medium. The latency of the virus through a HEPA is, accordingly, is problematic because many pathogenic viruses less than 0.1 μm in size, which is considerably smaller than 0.3 μm of test particles used for characterization of HEPA. Effective filtering of monodisperse viruses would have been nearly impossible. If viruses are enclosed in a water spray, HEPA filters, which are typically hydrophobic, lose their effectiveness when the accumulation of water. Filter medium according to this invention of nano-sized aluminum oxide provides higher efficiency and absorptive capacity, and therefore would be useful in the filtration masks and collective protection systems, for example, in hospitals and for protection against biological weapons.

Calculations

Based on the data presented in Table 1, the permeability B (m2for the examples is defined as:

B = vμz/ΔP [2],

where:

v - flow velocity, m/s, at a given ΔP;

μ is the viscosity of air. For air μ = 18,6·10-6PA·s;

z is the thickness of the environment;

ΔP is the differential pressure on the environment, PA.

Equation 2 assumes that the flow through the filter has a viscosity of finding the I in a given interval. In addition, in the case of measurement of gas flow requires two additional conditions [2]: (i) the pore diameter of greater than 1 micron, and (ii) the absolute pressure at the upstream side is not more than 1.1 times its value on the downstream side, that is, excessive pressure on the upstream side should not be more than 40 inches H2O when excessive pressure on the side of the lower reaches zero (i.e. 400 inches H2O absolute pressure). If these two conditions are met, then Equation 2 can be used to calculate permeability.

From Equation [2] and Figure 1 were determined by the permeability of the filter medium. The value of permeability and porosity were determined by the average diameter of the flow, d, as follows:

d2= 32B/ε2[3],

where ε is the porosity.

The diameters of the flow d is presented in Table 1. The average pore size of nano alumina medium was in the range of from 4.2 to 38 microns.

From Figure 1 as well as from similar graphs for the other samples, we determined the dependence of the linear velocity of air through the medium of the applied differential pressure; the obtained results are presented in Table 1. From these equations the value ΔP of the air (in mm of water column, excess.) in a linear course with a speed of 3.2 m/min compared with their values for HEPA.

Although the above description set forth in detail, it should be borne in mind that the examples and detailed descriptions of embodiments are for explanation and not for any restrictions. Can be made structural changes, especially in terms of shape, size and locations, however, in the framework of the principles of the present invention. Specialists in the art will understand that such changes or modifications to this invention or combinations of elements, variations, equivalents or improvements, however, are within the scope of the present invention, which is defined by the attached claims, and that the invention can be suitably used in practice in the absence of any restrictions that are not described clearly in this document.

Links

1. Henderson D. W., "An apparatus for the study of airborne infections", J. Hyg. Camb., vol. 50, 53-67 (1952).

2. Johnston, P. R., "Whadaya mean?", Filtration News, vol. 20, No 5, 10-ke (2002).

1. Filter for gaseous environment containing:
(a) nanoscale fibers oxide aluminia and
(b) a second fiber, mixed with these nano-fibers of aluminum oxide and selected from the group consisting of a glass micro-fibres, polymer fibres, cellulose or fibrillated cellulose, and each of these second fibers has a diameter in the range from about 0.6 μm to about 3.5 μm, while the second fiber is located with the formation of multiple asymmetric long which have an average size greater than about 10 microns and less than about 38 microns, the filter is able to filter particles whose size is at least an order of magnitude less than the specified average pore size.

2. The filter according to claim 1 which includes the second fibers include fibers, the smallest size larger than the small size of these nano-fibers of aluminum oxide is approximately one order of magnitude.

3. The filter according to claim 1 which includes the second fibers include a combination of coarse and fine fibers.

4. The filter according to claim 3, in which these thin fibers include fibers of more than one dimension.

5. The filter according to claim 1, wherein said filter is capable of removing more than 99.97% of particles 0.3 microns from humid air or gas stream.

6. The filter according to claim 1, in which the specified filter medium capable of removing more than 99.995% of a large number of penetrating particles from liquid or water spray.

7. The filter according to claim 1, in which the above asymmetric pores have an average size greater than about 5 microns.

8. The filter according to claim 1, in which the above asymmetric pores have an average size greater than about 10 microns.

9. The filter according to claim 1, in which the above asymmetric pores have an average size greater than about 20 microns.

10. The filter according to claim 1, in which the above asymmetric pores have an average size of b is than about 30 microns.

11. The filter according to claim 1, in which these nano-fibers of aluminum oxide have a size ratio of more than about 5, and the smallest size which is less than about 50 nm.

12. The filter according to claim 1 which includes the second fibers include glass fibers, fibrillated cellulose or cellulose.

13. The filter according to claim 3 which includes the coarse fibers selected from the group consisting of glass microfibers, cellulose or fibrillated cellulose, and these thin fibers selected from the group consisting of a glass micro-fibres, polymer fibres, cellulose and fibrillated cellulose.

14. The filter according to claim 1, also containing granular solid material.

15. The filter 14, wherein said granular solid material selected from the group consisting of fine silica, activated carbon and colloidal iron oxide.

16. The filter according to claim 1, also containing a binder.

17. The filter according to claim 1, also containing an antimicrobial agent.

18. The filter according to claim 11, in which specified an antimicrobial agent selected from the group consisting of silver, copper, zinc and their combinations.

19. The filter according to claim 1, in which the filter preprocessed with a multitude of particles having a diameter in the range of from about 0.3 to about 1.5 microns and selected from the group comprising ataxia particles, particles of granulated carbon particles are agglomerates of finely dispersed silica (Cab-O-Sil) and particles of metal oxides.

20. The filter according to item 21, in which the said particles have a size less than about 1.5 microns.

21. The filter according to claim 1, wherein said filter contains more than one layer.

22. The filter according to claim 1, wherein said filter is made in the form of a pile.

23. The filter according to claim 1, wherein said filter Gavrilova.

24. The filter according to claim 1, wherein said filter is combined with a filtration system for filtering specified gaseous environment.

25. The filter according to claim 1, in which the specified gaseous environment includes a suspension of water droplets.

26. The filter according to claim 1, wherein said filter is combined with a filter that is capable of removing more than 99.97% of particles 0.3 microns from the specified gaseous environment.

27. The filter according to claim 1, wherein said filter is capable of removing more than 99.97% of particles 0.3 microns from the specified gaseous environment.

28. The filter according to claim 1, wherein said filter is capable of removing more than 99.995% of a large number of penetrating particles.

29. A method of manufacturing a filter comprising the following stages:
a) mixing nanofiber alumina with an aqueous suspension containing the second fiber selected from the group consisting of a glass micro-fibres, polymer fibres, cellulose or febrile vannoy cellulose, each of these second fibers has a diameter in the range of from about 0.6 microns to about 3.5 microns; and
b) drying the specified suspension to form the specified filter containing many asymmetric pores have an average size greater than about 10 microns and less than about 38 microns, the filter is able to filter particles, whose diameter is at least an order of magnitude less than the specified average pore size.

30. The method according to clause 29, in which these latter fibers contain a combination of coarse and fine fibers.

31. The method according to item 30, in which these thin fibers have a diameter in the range from about 0.2 μm to 2.5 μm.

32. The method according to clause 29, also comprising a stage of forming the specified filter in the form of a single homogeneous layer.

33. The method according to clause 29, also comprising a stage of corrugating the specified filter.

34. The method according to clause 29, wherein said filter is made reactive by the interaction of aluminium powder with glass fibers in water at about 100°C.

35. Method of filtering gas environment, comprising the following stages:
a) passing a gaseous medium through a filter containing multiple nanofibers from aluminum oxide, mixed with lots of second fibers selected from the group consisting of a glass micro-fibres, polymer fibres, cellulose or fibrillarin the th cellulose, each of these second fibers has a diameter in the range from about 0.6 μm to about 3.5 μm, while the second fibers are arranged with the formation of multiple asymmetric pores have an average size greater than about 10 microns and less than about 38 microns; and
b) a delay in the specified filter basic number of particles of a specified gaseous environment, and the particles have a size which is approximately an order of magnitude less than the specified average pore size.

36. The filtering method according p, wherein said filter is used in the air filtration system of the premises.

37. The filtering method according p, wherein said filter is used to remove particles of paint material from the air or gas stream.

38. The filtering method according p, wherein said filter is used in a respirator.

39. The filtering method according p, wherein said filter is used in automotive air filter.

40. The filtering method according p in which the specified room is clean location.

41. The filtering method according p, in which the indicated location is operating.

42. The filtering method according p, which in the specified premises, at least one patient with a weakened immune system.

43. A method of manufacturing a filter comprising the following stages:
a) fo is the formation of nanoscale fibers of alumina and
b) the location of many other fibers selected from the group consisting of a glass micro-fibres, polymer fibres, cellulose or fibrillated cellulose, and each of these second fibers has a diameter in the range from about 0.6 μm to about 3.5 μm, in the form of a matrix with the specified nanoscale fibers of aluminum oxide to form a variety of asymmetric pores in which these dispersed nanosized fibers of aluminum oxide, each of these has an average pore size greater than about 10 microns and less than about 38 microns.

44. The method according to clause 29, in which the specified suspension is dried in the form.

45. The method according to clause 29, which to this suspension add-component fibers to increase the strength of the specified filter.

46. The method according to clause 29, in which the specified suspension contains a binder additive.

47. The method according to item 30, in which these coarse fibers selected from the group consisting of glass microfibers, cellulose or fibrillated cellulose, and these thin fibers selected from the group consisting of a glass micro-fibres, polymer fibres, cellulose and fibrillated cellulose.



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to making filtering materials for respirators. Filtering fibre material is proposed, as well as a method of making said material by electrostatic moulding microfibres from a polymer solution in an organic solvent. The material contains fibre of diametre 1-10 mcm from chlorinated polyethylene, characterised by mass content of chlorine of 60-70%, has surface density of 20-60 g/m and is used as the working layer of the respirator.

EFFECT: high mechanical strength of the material with high retention potential.

4 cl

Filtering element // 2375103

FIELD: textile fabrics, paper.

SUBSTANCE: invention is related to the field of water treatment. Filtering element for drinking water treatment is made in the form of bobbin wound at the angle of 12°-15° onto porous cylinder by two parallel cords with thickness of 1-2 mm from polymer ion-exchange fibre in mixture with activated carbon particles, besides one cord is arranged with the right twist, and the second one - with the left twist.

EFFECT: full use of filtering material components.

1 dwg

FIELD: textile fabrics, paper.

SUBSTANCE: invention is related to multilayer filtering materials. Suggested nonwoven material consists of inlet and outlet layers. Outlet layer consists of main and additional sublayers previously attached to each other. Inlet layer and main sublayer of outlet laye consist of mixture of hollow silicone fibre with linear density of 0.68 tex and polypropylene fibre with linear density of 2 tex, and additional sublayer of outlet layer consists of polypropylene fibre with linear density of 0.68 tex. Ratio of surface densities of inlet and outlet layers makes 1:1÷1:1.5.

EFFECT: improved operational properties.

2 dwg

FIELD: means of protection.

SUBSTANCE: invention relates to production of a filtering and sorbing material used in the means of personal respiratory protective equipment to cleanse the air form fumes and aerosols of hazardous substances. The filtering and sorbing material containing polypropylene fibers filled with microatomised carbon, fibers of sulfate unbleached cellulose and fibers of mercerised cellulose is obtained by adding the polypropylene fibers in the amount 5-10% of the total mass at the stage of grinding the sulfate unbleached cellulose after which combined grinding of the mixture is continued until the grinding degree of 28±2°SHR is reached, the mixture is then mixed with the fibers of mercerised cellulose and carbon, paper web is poured dried and treated with an impregnating solution containing nickel chloride (II) - 10%, ferrous chloride (III) - 10%, copper chloride (II) - 10%.

EFFECT: production of elestic well draped filtering and sorbing material with high mechanical and adsorbtion characteristics and a low aerodynamic resistance to respiration.

1 tbl, 1 dwg

FIELD: medicine.

SUBSTANCE: method involves as follows. Electroformed nonwoven fibrous polymer fabric is impregnated with aqueous or aqueous-alcoholic suspension of aluminium material particles then hydrolysed by heating the suspension impregnated fabric that is impregnated by suspension spraying over its surface. The heating process in performed in the open air at relative humidity at least 70%, preferentially 95-100% of at least two stacked suspension impregnated fabrics. Upon termination of hydrolysis process, plane parallel wringing of the fabrics follows.

EFFECT: improved performance of a sorbent owing to formation of the composite sheet sorbent involving uniform distribution of porous particles of oxide-hydroxide aluminium phases over the entire volume of the fabric, formation of the sheet sorbent fabric of uniform thickness and density.

7 cl, 2 ex, 1 tbl

FIELD: technological processes.

SUBSTANCE: invention is related to the field of fibrous filtering materials. Filtering material is suggested for respirators, which contains working layer of fibres with diametre of 1-10 mcm produced by method of electrostatic moulding from solution containing 6-16 wt % of polycarbonate in mixture of dissolvents that consists of dichloroethane and methylene chloride with their mass ratio of (1-5):(9-5), accordingly, and having surface density of 30-60 g/m2. Respirator is made with application of produced material.

EFFECT: improved mechanical strength of material and products on its basis.

4 cl, 1 dwg, 2 tbl

FIELD: technological processes.

SUBSTANCE: electret article comprising polymer material, which has electret charge given to it, besides, polymer material includes one or several types of heteroatoms, and coefficient of saturation with fluorine that represents ratio of atomic percentage ratio of fluorine relative to amount of saturated and unsaturated fluorine-containing groups, does not exceed approximately 200, moreover, atomic percentage content of fluorine makes at least approximately 40%. Article is used as filtering material in respirators, filters and face masks.

EFFECT: provision of high quality of material.

22 cl, 5 dwg, 8 tbl

FIELD: textile, paper.

SUBSTANCE: invention relates to fibrous filtering materials. Filtering fibrous material is proposed which is produced by electrostatic formation from a solution of polymer mixture - sterol copolymer with acrylonitrile and polyurethane with their weight relation of (50-95):(50-5) respectively, diametre of 1-10 mcm; the material is characterized by the unit area weight of 2070 g/m2 and aerodynamic resistance of 3-30 Pa under the air flow speed of 1 cm/s. Method of the material production and respiratory personal protective gear made from it are proposed as well.

EFFECT: providing for effective filtering material with improved physical and chemical parametres.

5 cl, 1 dwg, 2 tbl, 4 ex

FIELD: chemistry.

SUBSTANCE: filter is made of nonwoven fabric and/or injected filter structures or sheets, i.e. produced after processing the synthetic artificial fibres. At first fibres are processed with antibacterial compounds and sliced to monothreads. Natural, artificial, synthetic, metal fibres or their mixtures are used. Web and felt are formed from these threads. Required number of nonwoven fabric layers is connected, thereafter processed, sliced and rolled.

EFFECT: extended application of aforesaid filters, improved wetting and filtering ability ensured.

31 cl, 16 dwg, 11 ex

FIELD: technological processes.

SUBSTANCE: invention is related to the field of fibrous filtering materials production. Materials are suggested from polystyrene and polymethyl methacrylate with fiber diameter of 1.5-3 mcm. Materials are produced by means of electrostatic moulding of fibres from polystyrene or polymethyl methacrylate solution in organic dissolvent, which is ethyl acetate or dichloroethane that have been previously purified till content of admixtures is not more than 0.001 wt %, at that polystyrene and polymethyl methacrylate prior to dissolution are purified till content of admixtures is not more than 0.01%, and electric moulding is realised in air medium, which is dust-free till particles content is not more than 0.01 mg/m3 and relative humidity of not more than 35%.

EFFECT: invention makes it possible to produce filtering easily-cindered materials that are efficient in analysis of gas mediums for inorganic aerosol admixtures.

3 cl, 1 tbl, 2 ex

FIELD: methods of production of electret items, electret filters and respirators.

SUBSTANCE: the invention presents a method of production of electret items, electret filters and respirators with heightened resistivity to the oil mist. The invention falls into production processes of electret items, electret packed beds and respirators, and may be used for removal of corpuscles from gases, especially for removal of aerosols from air. The method provides for: formation of a melted material consisting of a mixture of a polymer composed of a mixture of a polymer representing a non-current-conducting thermoplastic resin with a specific resistivity exceeding 1014 Ohms·cm with a fluorine compound as an additive compound; shaping it to the required form and quenching it up to the temperature lower than the melting point of the polymer. The material is calcined and treated with an electric charge to give it electret properties. The invention improves the capability of filtering oily aerosols.

EFFECT: the invention improves the capability of filtering oily aerosols.

19 cl, 16 tbl, 19 dwg, 23 ex

FIELD: methods for imparting charge to fibrous webs by means of non-aqueous liquid for usage of said webs as filters in filtering face masks for protection of user's mouth and nose.

SUBSTANCE: method involves wetting web formed from non-conductive fibers with non-aqueous polar liquid; substantially drying web for producing fibrous electronic web. Method differs from known methods of imparting charge to web in that it requires less energy for drying of web than methods using aqueous liquids. Also, many kinds of filaments poorly wetted with aqueous liquids are immediately wetted with non-aqueous liquids.

EFFECT: increased efficiency and simplified method.

12 cl, 2 dwg, 6 tbl, 26 ex

FIELD: fine-fiber filtering materials.

SUBSTANCE: the invention is pertinent to fine-fiber filtering materials used for individual means of protection of respiratory organs. The invention offers a protection material, a means of protection containing the offered material and a method of production of the fibrous material providing for electrostatic forming of the fibrous material from a solution of styrene copolymer with acrylonitrile in an organic solvent at the presence of electrostatic additives of bromide or iodide salts of tetraethyl- or tetrabutyl-ammonium. At that a solution containing an additive of a high-molecular methylmethacrylate in amount of 0.001-0.01 mass % in the capacity of dissolvent is used a mixture of ethyl acetate with butyl acetate at their mass ratio in the solution from 1/9 up to 9/1 accordingly. The invention allows to produce a material with improved mechanical characteristics and to provide stability of the production process.

EFFECT: the invention ensures production of the material with improved mechanical characteristics and stability of the production process.

5 cl, 2 tbl, 1 ex

FIELD: fine filtration of air; cleaning ventilation emissions from oil mist; cleaning air in venting pipe lines of gas-transfer unit oil tanks.

SUBSTANCE: proposed filter includes filter element with filter medium made from coarse and fine fibers laid in between outer and inner cylinders, cover and bottom. Filter medium is made from longitudinal and transversal oil-resistant synthetic (polypropylene) fibers; ratio of mass of longitudinal and transversal fibers is equal to (6-8) : 1 and ratio of diameters of thin and coarse fibers is equal to (0.5-1) : 10.

EFFECT: enhanced efficiency of cleaning at considerable increase of service life, oil return coefficient; enhanced ecological safety around compressor stations.

2 cl, 2 dwg

FIELD: filtering materials for liquid and gaseous fluids.

SUBSTANCE: filtering material is made of thermoplastic polymeric fibers. The density of material increases downstream, whereas the diameter of fibers decreases downstream. The inner layer of the material has areas the density of fibers in which is lower than the averaged density of upper layers by a factor of 2-6.

EFFECT: enhanced strength.

1 dwg, 1 tbl

FIELD: polymer materials and gas treatment.

SUBSTANCE: invention relates to polymeric fibrous filter materials designed for effective cleaning of air stream due to realization of mechanical and electrostatic filtration. Material suitable for use in respiratory masks contains (i) a layer in the form of cloth 1 mm thick made from polypropylene fibers with diameter 0.5-1.5 μm, packaging density 0.25-0.30 g/cm3, and electric charge with surface density 17-21 nCl/cm2, the layer being made by aerodynamic atomization of melt and electrization of fibers in corona discharge field during their formation, and (ii) an additional layer in the form of non-electrized cloth 1 mm thick made from polypropylene fibers with diameter 10-20 μm and packaging density 0.25-0.30 g/cm3, which is placed on the side directly facing air stream to be cleaned, the two layers being attached to each other by spot weld. Presence of two layers results in separate but complementary realization of mechanical and electrostatic filtration.

EFFECT: enhanced air cleaning efficiency and prolonged lifetime of filter material.

1 tbl

FIELD: methods and devices used for production of fibrous electret linen.

SUBSTANCE: the invention is pertaining to methods and devices used for production of fibrous electret linen. The method of giving of an electrostatic charge to the fibrous non-woven linen provides that the fibrous linen is soaked with a wetting liquid, then it is saturated with a water polar liquid and dried. The gained dry product represents an electret, which may be efficiently used in the air filters, for example, in respirators.

EFFECT: the invention ensures production of a fibrous electret linen, which may be efficiently used in the air filters, for example, in respirators.

13 cl, 3 ex, 5 tbl, 4 dwg

FIELD: chemical industry; oil refining industry and other industries.

SUBSTANCE: the invention is pertaining to production of materials for the filtering water-separating elements used in devices for purification of organic fluids, predominantly, hydrocarbon fuels, oils, oil products from the emulsified water and mechanical impurities, and may be used for purification of aircraft and car fuels in chemical industry, oil refining industry and other industries. The porous reinforced material is produced out of a permeable in all directions polymeric material with a side-porous deep structure having a total porosity of no less than 50 % with the sizes of the elementary pores, predominantly, of 10 - 200 microns. At that the porous reinforced material is formed out of a framed material having filaments or fibers with a diameter, predominantly, of 5 - 400 microns, and an arranged between the above mentioned filaments or fibers filler manufactured out of a porous polyvinyl formal produced by the method of a dew-point structurization with the thermal treatment of a homogenized in water composition containing at least polyvinyl alcohol and aldehyde. The element for the screen-water-separator contains a filtering-coagulating septum embraced by a perforated shell rings and limiting from above and from below covers. At that the septum is made multilayered out of a sheet manufactured out of the above porous reinforced material. The technical result consists in an increased effectiveness of purification of fuels (jet engine fuels and diesel fuels) and the gaseous oil products from water, and also asphalt-resinous and sulfur-containing materials, an increased service life and productivity of the filtering screens based on the indicated filtering-coagulating material.

EFFECT: the invention ensures an increased effectiveness of purification of jet engine fuels, diesel fuels, gaseous oil products from water and also asphalt-resinous and sulfur-containing materials, service life and productivity of the filtering screens based on the filtering-coagulating material.

13 cl, 3 dwg

FIELD: methods of production of filtering materials.

SUBSTANCE: the invention is pertaining to the methods of production of filtering materials, in particular, to the method of production of the filtering fibrous materials, which may be used in a means of individual protection. The filtering fibrous material is produced by an electrostatic formation of a non-woven fibrous material from a working polymeric fiber-forming solution with dynamic viscosity of 1-30P, electrical conduction of 10-4-10-7 ohm-1 cm-1 in an electrostatic field at a potential difference from 10 up to 150 kV. The solution contains in the capacity of the polymer from 8.9 up to 24.6 mass % of styrene copolymer with 5.2-30.4 mass of acrylonitrile or triple styrene copolymer with 5.2-30.4 mass of acrylonitrile and 3.7-42.1 mass % of methyl methacrylate. As a dissolvent they use ethyl acetate, or butyl acetate either their mixture. The solution in addition contains high-molecular polymethyl methacrylate, a distilled water, the lowest alcohol taken from the group ethyl alcohol, methyl alcohol or isopropyl alcohol, at the following contents of ingredients of the polymeric fiber-forming solution, in mass %: polymeric compound - 8.9-24.6; high-molecular polymethyl methacrylate - 0.011-0.02; distilled water - 0.01-0.1; the lowest alcohol - 17-28; dissolvent - the rest. The efflux of the working polymeric fiber-forming solution is exercised at the volumetric speed of 0.1 up to 6 cm3 /minute. Feeding of the working polymeric fiber-forming solution is conducted from the space interval of 12-42 cm beginning from the point of its coming out from the batching device up to the settling surface. The produced filtering fibrous material contains a technological and a working layers made out of the polymeric fibrous material produced by the above described method. The technological layer material has the surface density of 1-3 g/m2 and is made out of fibers of 3-5 microns diameter. The working layer material is made out of fibers of 1.5-3 microns diameter. The double-layer material has the surface density of 32-38 g/m2, the standard resistance of 0.8-1.2 mm of the water column and the skip coefficient of no less than 95 %. The invention ensures an improved quality of the filtering material due to an increase of efficiency of penetration of fragments with a diameter of 0.3 microns at the standard resistance of 1.0 mm of the water column.

EFFECT: the invention ensures an improved quality of the filtering material, an increased efficiency of penetration of fragments with a diameter of parts of microns at the standard resistance of 1 mm of the water column.

4 cl, 2 ex

FIELD: natural gas industry; petrochemical industry; oil-producing industry; other branches of industry; methods of production of filtering materials and the filters for purification of gases and aerosols.

SUBSTANCE: the invention offers the filtering material made out of the polysulfone fibers with different diameter of the fibers produced by electromolding from the solution in the organic solvent with addition of an electrolyte; and the frame design filter supplied with the produced material having the density of 30 - 50 g/m2. The invention ensures the effective filtration of the aerosol particles at the high thermostability of the filter.

EFFECT: the invention ensures the effective filtration of the aerosol particles at the high thermostability of the filter.

5 cl, 1 tbl, 1 dwg

Up!