Method of ultrasonic cavitation processing of fluids and objects placed therein
FIELD: process engineering.
SUBSTANCE: invention relates to treatment of fluids by cavitation. Oscillatory system with fluid and objects consists of walls each being made up of membrane secured on its edges that features intrinsic frequency equal to first harmonic, allowing for oscillator weight. Ultrasound waves are emitted by all membranes at a time to produce superposition of waves with generation of standing acoustic waves or several waves with different frequencies. Amplitude of resonance oscillation of every membrane exceeds the threshold of acoustic cavitation for fluid and objects therein. Membrane frequencies and phase characteristics are selected to mate or to differ to produce cavitation effects with due allowance for medium characteristics. Oscillatory system may have arbitrary shape, flow or stationary mode of fluid motion.
EFFECT: higher efficiency of cavitation effects.
The invention relates to the field of cavitation treatment of liquid media, as well as environments where specific content of water or other liquid phase exceeds 65-70% of the total mass of the treatment of items in the treated liquid medium. It is known that the acoustic ultrasonic cavitation can be effectively applied to various areas of the economy, which implements the following processes /1-6/:
- Homogenization and emulsification;
In practice, this covers the processes for multicomponent fluids (emulsions, suspensions, aqueous solutions and systems), ultrasonic sterilization (disinfection) of water, milk, other products, cleaning tools and medical supplies, etc.
The method of processing liquid media, which is implemented in the circuit of the ultrasonic reactor, can be adopted for the prototype /1/. It lies in the fact that the ultrasonic wave in the fluid volume created with the help of core radiator, at the end of which is a source of oscillations, as a rule, piezoelectricity emitter. There are many variants of calculations form the core of the radiator and mounting on his butt several pietistically, but they are all aimed at increasing the amplitude of oscillation of the rod on ignem end and side walls /8/. This is due to the fact that the zone of developed cavitation in practice is measured by the size of a few centimetres from the surface oscillations. Thus, the bottom part of the rod is considered the most effective area, as between the flat end face of the emitter and the flat bottom is formed by a standing wave in the treated fluid. It is noted that the diameter of the end is harder to do with larger 50-70 mm Radiation from the cylindrical surface of the rod has a substantially smaller amplitude and a cylindrical divergence. Taking into account the reflected acoustic waves from the walls of the outer cylinder of a glass can be estimated that the optimal regime of stable standing flat coherent ultrasonic waves in the treated liquid medium, by analogy with minor area between the end face of the radiator and the bottom of the cylinder-glass, to obtain almost impossible. A complex picture is transmitted and reflected ultrasonic waves in the medium, the lack of coherence of the wave and the concentration of energy at the same frequency leads to the fact that to obtain emulsions with the size of the dispersed phase of less than 0.8 to 1.0 μm is practically impossible, the level of homogeneity does not exceed 20% of the main fashion. The volume of the treated fluid is limited.
Another alternative method of ultrasonic cavitation treatment of liquid media implemented in rotary pulse the ion homogenizers /2/.
The camera sound, due to the intermittent alternating fluid flow from the rotating system of the stator-rotor occurs ultrasonic wave with cavitation effects. This is an intermediate option between acoustic and hydrodynamic cavitation. Such homogenizers got currently most popular. They are quite simple, allow the handling of large volumes of liquid, substantially cheaper than ultrasonic counterparts. Good speed homogenizers allow the emulsion to the size of the dispersed phase of ~1.5 μm on the main fashion, the level of homogeneity does not exceed 12-15%. Nevertheless, this method has some fundamental limitations.
This is due to the low efficiency of Electromechanical systems (up to 10%), which limits the power of the ultrasonic waves up to 1.5-2 watts/cm2not allows you to work with viscous media, with the processing of static volumes of fluid (in the volume of the stator-rotor) and imposes a number of other major restrictions.
The closest is essentially the way the cavitation treatment of liquid flow and the reactor for its implementation in patent No. 2246347 from 25.08.2003 LLC Astor-C".
The fluid flow is passed through the resonance cell cavitation reactor, where the liquid set a standing acoustic wave with specified which one is the volumetric power density. Resonance cell is a diaphragm with a hole in the housing, and the diaphragm is placed in a plane parallel to the oscillatory movement of the walls of the resonance cell.
Due to the undulating motion of the liquid medium within the reactor having one or more stationary cavitation fields.
However, this technology has a number of restrictions on use. This is due to the fact that the liquid medium inside the reactor has limited cavitation effects, which will vary depending on the hydraulic regime of the flow and its properties. In the process, circular flow of the treated fluid through the reactor, its properties, such as viscosity emulsions, suspensions, can vary within wide limits. Difficult is the use of this method for processing objects that are placed into the liquid medium from the outside. In addition, it was repeatedly noted that cavitation effects significantly increase if the liquid to be treated at two different frequencies. At 5, p.60/ States that "while ultrasonic waves of two different frequencies (22-44 kHz) observed a significant increase in the efficiency of cavitation, much more than in a linear summation of the effects of each of the fields of different frequencies".
In the prototype of the processing fluid at different frequencies is problematic.
The aim of the invention is to increase the efficiency (power and amplitude of the acoustic waves, coherence) cavitation effects on the treated liquid medium and placed in an environment objects while limiting the power of ultrasonic emitters.
This goal is achieved by the fact that the vibrational system with liquid medium and objects consists of wall-surfaces, each surface is fixed on the contour of the membrane, for example on a rigid frame, having a natural frequency with regard to added masses of pathogen variation of the first harmonic, the radiation of the ultrasonic waves in the liquid medium is carried out simultaneously from all membranes vibrating system, providing the processed volume effect of superposition of waves with the formation of a standing acoustic wave or multiple waves with different frequencies, the amplitude of the resonant oscillation of each of the membrane exceeds the threshold of acoustic cavitation for liquid medium placed in her objects, the oscillation frequency and phase characteristics of vibrations of the membrane are selected so that they can match or be different to obtain the maximum required cavitation effects, taking into account the characteristics of the treated environment, while oscillatory system can the be of arbitrary shape, flowing or stationary mode of motion of a liquid medium.
In the proposed method uses the principle of sequential resonant amplification of acoustic waves at a given frequency, or multiple waves at a given frequency.
The first amplification oscillation amplitude is resonant characteristic of the membrane oscillations which are excited by an external source, for example the system.
It is known that membrane, in contrast to the plates do not have Flexural rigidity and have a higher frequency of natural oscillations. The frequency of oscillation of the membrane does not depend on its thickness, in contrast to the plates. The specific mode of operation of the membrane-plate depends on several factors such as the conditions attaching to the edges (tension), the amount of deflection, frequency of exposure, etc. /8/.
For a rectangular membrane with fixed edges, the solution of the wave equation in the set of frequencies of natural oscillations in the Cartesian coordinate system has the form /7/:
where C is the speed of wave propagation on vinyl;
kx, kywave numbers whose values are determined by the boundary conditions;
Lxthe side length of the plate is directed along the axis ox;
Lythe side length of the plate is directed along the axis of the Shelter;
jxI , jyis an integer equal to the number of antinodes of the wave along the respective sides of the plate.
To obtain maximum benefit from the membrane it is necessary to implement the resonant mode at the first fashion, when the number of antinodes is equal to 1 on both axes. In this case, all points of the membrane vibrate on the same frequency and phase with the maximum deflection in the center of the membrane. Figure 1 presents a typical resonant characteristics of the membrane with a size of 250×145 mm, 1.2 mm thick, made of nerjaveyuschei steel AISI 316 (similar HT)with the speed of longitudinal waves ~5800 m/s it is Seen that the resonant frequency ~23,2 kHz q of the vibrating system-cascade is ~7. This allows to significantly increase the amplitude of the acoustic wave in the fluid in contact with this surface, with limited powers applied to the system.
The second amplification stage charactistic acoustic waves is the formation of standing waves in the liquid or in the area of object processing due to the superposition of the reflected and incident waves from the walls-surfaces.
For example, if the oscillating system has the form of a rectangular tank that is open on one side, it may contain five radiating surfaces of the membranes. Figure 2 presents the reactor 4 radiating surfaces (5 side - supply pipes for liquids). The frequency of oscillations of membranes for 23.2 kHz and 46 kHz.
Dunn is the first method can be applied in various industries.
Figure 3 and Figure 4 shows the result of ultrasonic steps to the sand and concrete mix (frequency of 23.8 kHz). The cavitation effect reduces the size of the solid phase, end strength increasing by 20-25% while reducing the time of solidification by ~15% at the same temperature.
Figure 4 shows the result of dispersion of milk fat content of 1.5% at a frequency of 46 kHz. The obtained stable ultrafine milk emulsion (~500 nm, calibration 7) allows to produce products with extended shelf life and high nutritional value.
Figure 5 shows the effect of ultrasonic treatment (frequency of 24.8 kHz) paraffin oil. Experiments conducted with oil, where paraffin was 10%, 17%, 26% and 50% (optional paraffin was dissolved). It is shown that ultrasonic treatment leads to partial destruction of paraffins, rheological properties of paraffin oil significantly improved the crystallization temperature of the wax is reduced by ~15 degrees (43-45 degrees), the viscosity decreases in 2.5-3 times at the same temperature, time delay, taking into account thixotropic properties of paraffin becomes unlimited.
Figure Fig shows the effect of cavitation on the objects that can be processed in liquid medium. When the superposition of acoustic waves from all membranes is nabludaetsa significant strengthening of cavitation exposure. To evaluate the relative cavitation effects were used metal foil.
Thus, the proposed method cavitation treatment of liquid media and located in the environment of objects implementing and allows you to raise the efficiency with minimum energy consumption with the possibility of simultaneous processing at different frequencies.
1. Bronin FA Study cavitation destruction and dispersion of solids in the ultrasonic field of high intensity. Author's abstract on competition of a scientific degree of candidate of technical Sciences, MISA, 1967.
2. Worms VM, Odnako VG hydrodynamic and cavitation phenomena in rotary machines. - M.: Publishing house engineering, 2008.
3. Bergman L. Ultrasound and its application in science and technology. - M.: Foreign literature, 1956.
4. Sirotyuk MG Experimental study of ultrasonic cavitation. In kN. Powerful ultrasonic fields. Ed. by L.D. Rosenberg, 1968.
5. Margulis M.A. fundamentals of zvuchanie. Chemical reactions in acoustic fields. - M.: Higher school, 1984.
6. Khmelev V.N., Popova O.V. Multifunctional ultrasonic devices and their application in small industries, agriculture and at home: research monograph, Alt. GOS. Technology. Univ them I.I.Polzunov. - Barnaul: Publishing house of the Altai state technical University.
7. The top NS, the liner AB, Smirnov M.M. partial differential Equations of mathematical physics. M., publishing house of the Higher school, 1970.
8. Vibrations in engineering. The reference in 6 volumes, edited by V.N. Chelomei., M., engineering, 1979.
The method of ultrasonic cavitation treatment of liquid media and located in the environment of objects by placing them inside a mechanical oscillatory system, where the implemented mode acoustic cavitation due to resonance vibrations of the walls of the channel of rectangular cross-section and the addition of standing waves in the processing environment, characterized in that the oscillatory system with the liquid environment and the objects may have any shape, flowing or stationary, the driving mode of a liquid medium, each surface is fixed on the contour of the membrane, for example, on a rigid frame, having a natural frequency with regard to added masses of pathogen variation of the first harmonic, the radiation of ultrasonic waves in the liquid medium is carried out simultaneously from all membranes vibrating system, providing the processed volume effect of superposition of waves with the formation of a standing acoustic wave or multiple waves with different frequencies, the amplitude of the resonant oscillation of each of the membrane exceeds the threshold of acoustic cavitation for liquid placed in it the objects is, the oscillation frequency and phase characteristics of vibrations of the membrane are selected so that they can match or be different to obtain the maximum required cavitation effects, taking into account the characteristics of the treated environment.
FIELD: process engineering.
SUBSTANCE: invention relates to cleaning of dispersed materials of impurities in fluid flow. Proposed apparatus comprises cylindrical casing with reagent feed branch pipes arranged at different height, conical part arranged under cylindrical casing and discharge branch pipe. Cylindrical section with initial material feed branch pipe is arranged above cylindrical casing and provided with slime discharge cavities arranged concentrically over its height. Additionally, reagent feed branch pipes are arranged in said conical part. Perforated nozzles are arranged inside cylindrical casing distributed over its height while ultrasound transmitters are secured on its outer surface. Conical an cylindrical sections are acoustically isolated from cylindrical casing that makes resonant cavity of ultrasonic oscillations. Reagent feed branch pipes and perforated nozzles are arranged inside cylindrical casing so that, at preset reagent feed pressure, reagents are fed in counter-current with flow of material being cleaned.
EFFECT: higher efficiency, reduced consumption of reagents.
2 cl, 1 dwg
SUBSTANCE: invention refers to the device and method of engine details cleaning. The detail includes igniter plug of gas turbine engine. The engine includes internal channel of flowing medium. To create hydraulic seal the cap is installed. The cap includes ultrasonic transmitter. Cleaning flowing medium is fed to contact with the detail through supply channel. Cleaning flowing medium is mixed by ultrasonic transmitter. The cleaning washing medium is then deleted through discharge channel.
EFFECT: increased effectiveness of engine details cleaning.
3 cl, 3 dwg
FIELD: machine building.
SUBSTANCE: procedure consists in components washing in three baths of ultra-sonic process complex: in first bath - in water solution of alkali detergent of concentration 100-150 g/l and temperature of solution 80-90°C and with superposition of ultrasound, in second bath - in water with implementation of compressed air bubbling, in third bath - in water solution of acid technical detergent "MUK-K" of concentration 100-150 g/l and temperature 20-70°C with superposition of ultrasound, and in successive components drain in second bath.
EFFECT: ecological safety of process, reduced prime cost and labour input, raised efficiency and quality of components drain.
1 dwg, 1 ex
SUBSTANCE: procedure for cleaning steel sheet and system of continuous steel sheet cleaning consists in supply of cleaning solution activated with ultra-sonic vibrations of 0.8-3.0 MHz frequency to surface of steel sheet at angle of 1 - 80° relative to line perpendicular to surface of steel sheet in direction opposite to direction of transfer.
EFFECT: development of procedure for steel sheet cleaning and system of continuous steel sheet cleaning with usage of mega-sound vibrations to facilitate efficient removal of scale generated during fabrication of steel sheet.
6 cl, 8 dwg, 3 tbl, 3 ex
SUBSTANCE: method of cleaning wire in aqueous solutions of detergents in form of one or more flat-elastic waves which give rise to cavitation through oscillations at ultrasonic frequency, involves moving the cleaned wire and the detergent solution along a beam which is common for said waves, as well as moving the wire and the detergent solution in opposite directions. The device has one or more acoustic cells. The volumes of the cells are cylindrical cavities lying on the axis of symmetry of a solid waveguide with coaxially connected coherent sources of ultrasonic oscillations. The radiating surfaces are surfaces of their bases which belong to partitions which have openings for free passage of the cleaned wire and detergent solution between volumes of the cells, as well as caps on both ends of the waveguide. The waveguide has outlet and inlet nozzles of that solution.
EFFECT: invention increases efficiency of cleaning without increasing dimensions and power consumption of the cleaning device by exciting elastic oscillations using one acoustic waveguide and non-parametric amplification of cavitation and provides rectilinearity of the path of motion of the wire.
6 cl, 11 dwg, 1 tbl
FIELD: process engineering.
SUBSTANCE: invention relates to surface cleaning by continuous swirling fluid flow that tears off dirt particles from surface. Proposed method consists in that surface is scanned by continuous fluid flow wherein ultrasound oscillations are generated (injected). Fluid flow is swirled along its axis. Inertial forces generated thereby create hydrodynamic abrasive effect.
EFFECT: higher efficiency.
FIELD: process engineering.
SUBSTANCE: invention relates to in-line sonochemical cleaning of roller bearing elements and to method of its readjustment. Proposed device comprises one or several sources of equal-frequency ultrasound oscillations with flat equal-size radiating surfaces and gravity conveyor chutes replaced depending upon element type size to make elements roll by gravity parallel with radiating surfaces. Distance from conveyor trajectory plane to radiating surfaces along normal line does not exceed one-and-a-half wave length of ultrasound oscillations in solution. Conveyor trajectory nearby chute for outer races is located at the distance from normal lines running from geometrical centers of radiating surfaces not exceeding 15% of maximum size of radiating surface perpendicular to conveyor trajectory. Conveyor trajectory nearby chute for inner races and balls is located at the distance of 1/2…3/4 of said size. Proposed method consists in replacing the chute to suit type size of cleaned bearing, setting acoustic power of ultrasound oscillation sources and conveyor stroke. Conveyor stroke cycle required for cleaning in seconds is determined mathematically.
EFFECT: higher efficiency of cleaning.
2 cl, 7 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to systems designed to clean long elements of surface contamination, particularly heat-releasing system elements of nuclear power stations. Proposed module comprises chamber, washing appliance, part attachment, drain pipeline, working agent feed system and safety valve. Washing chamber represents branch pipes-resonators flanged together to produce ultrasound oscillations of various or identical frequency and acoustically decoupled by elastoplastic spacers arranged between flanges. Ultrasound radiators are secured to said resonators from outer side.
EFFECT: higher efficiency.
2 cl, 2 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to ultrasound cleaning of process and operating impurities. Proposed method consists in the following. Article placed in vessel with detergent is subjected to ultrasound oscillations generated by the main high-amplitude radiation source that provides 15 to 20 mcm amplitude of oscillatory displacements and 20 to 30 kHz frequency, and generates fluid flow with cavitation properties directed onto article. Note that additional power flux is directed to said article. Note also that low-amplitude ultrasound radiation power is used that creates, together with the main source radiation, a common zone distant from the latter which brings about a stable cavitation effect on the article due to interaction of two acoustic flows. Said common zone extends for L=(4-5) l, where l is the distance from the main source active acoustic effect length.
EFFECT: additional zone of erosion effects in detergent wherein no destruction of impurities occurs.
FIELD: technological processes.
SUBSTANCE: invention is related to devices for ultrasonic cleaning of small-size, mostly, metal items from various types of contaminants. Device is intended for ultrasonic cleaning of small-size items in aqueous washing detergents and comprises one or several resonant cells as sources of ultrasonic oscillations. Size of each of these cells in direction of beam of still flat-elastic wave in process of operation in washing detergent, expressed in millimetres, is selected from the row of (732±32)·N·n, where N is number equal to value of ultrasonic oscillations period, expressed in milliseconds; n is actual integer number.
EFFECT: device is simple and universal in relation to aqueous washing detergents, since it is not required to change spatial position of ultrasonic devices and control of their power.
SUBSTANCE: mixer includes the body with connections for input of the viscous and low-viscous raw material components. The connection for output of the ready mixture is designed as knee-shaped branch pipe located along the vertical body axis. The tubular device provided with nozzles and intended for input of the low-viscous raw materials component is positioned in the lower part of the body The said tubular device is connected by the pipe-line with head piece positioned in the upper part of the body and provided with tubes which are able to direct the crossed jets tangentially to the inner surface of the body.
EFFECT: efficiency enhancing of the mixing and exclusion of the ingress to the ready raw materials of the mechanical admixtures containing in the raw materials flow mixture.
3 cl, 2 dwg
FIELD: petrochemical industry; methods and devices of the superlight fuel oil production.
SUBSTANCE: the invention is pertaining to the field of petrochemical industry, in particular, to the method and the device for production of the superlight fuel oil. The superlight fuel oil is used as the technological fuel at the industrial enterprises, at heat supply enterprises, and also by the sea and river fleet ships. The superlight fuel oil contains 25-50% of the stabilized gaseous condensate with the contents in it of the fractions C1-C4 in the amount of no more than 0.3-1.0 % and the rest is the fuel oil of the furnace brand М100 and-or М40. The method of production of the fuel oil provides for mixing of the heated up to 50°C fuel oil of the furnace brand Ml00 and-or М40 with the stabilized gaseous condensate with the temperature of 20°C under pressure up to 3 atm in the given ratio in the chamber of the components mixing. Then the produced mixture is fed into the emulsification device, where it is subjected to the ultrasonic treatment for production from the fuel oil mixture of the finely dispersed emulsion. The subsequent remixing of two and more streams of the finely dispersed emulsion of the fuel oil mixture with the permanently maintained temperature pf 50-60°C is conducted in the chamber of the intensive mixing due to organization of intermixing by the counter currents under pressure and transportation of the target product into the containers of the accumulators integrated by the system of circulation, subjecting the end product to the constant circulation under the pressure of up to 2 atm and to passing through the emulsification device. The invention also presents the installation of production of the superlight fuel oil, which contains the components supply systems and the mixing chamber. The supply system of the gaseous condensate and the supply system of the fuel oil each contains: the pump; the leak valve and the consumption indicator for the components feeding into the mixing chamber; the ultrasonic emulsification device; the chamber of intensive mixing with the preheating; the accumulator consisting of the container, the leak valve of an end product with the consumption indicator and the leak valve of the feeding of the superlight fuel oil to the customer. The system is integrated with the circulating system. The circulating system includes additional container, the pump, the leak valve, the consumption indicator. The technical result of the invention is the increase of the flowability and the service life of the produced product, improvement of the ecological indexes of the fuel oil per a unit of the heat capacity due to application of the simple production equipment and the optimal composition of the fuel oil.
EFFECT: the invention ensures the increased flowability and the service life of the produced fuel oil product, improvement of ecological indexes of the fuel oil per a unit of the heat capacity.
3 dwg, 1 tbl
SUBSTANCE: invention relates to medical equipment, particularly to ultrasonic therapy device. Device includes medical tank housing medium, ultrasonic elements, ultrasonic element excitation system, work zone and ultrasonic vibrators. Ultrasonic elements generate ultrasonic waves in medical tank and decompose water in the medium, generating hydroxyl radicals. Ultrasonic vibrators are positioned on the bottom wall of medical tank and serve for ultrasonic wave distribution. Additionally, all ultrasonic elements feature air layer on rear surface of ultrasonic element. Work zone serves for setup of ultrasonic radiation time, ultrasonic wave frequency, medium temperature and ultrasonic wave output.
EFFECT: increased aseptic effect of treatment not involving drugs.
4 cl, 6 dwg
SUBSTANCE: invention relates to field of purification and protection of environment inside inhabited orbital stations from destroying influence of microorganisms. Method of destroying microorganisms-biodestructors on surface of objects in dwelling modules of space station includes periodic irradiation of mentioned zones with ultrasound with frequency more than 29 kHz and level of irradiation more than 150 dB during time period necessary for conversion of condensate with microorganisms into dispersion aerosol, removal of formed aerosol from air medium of irradiated zones by suction of air of irradiated zone medium trough filter, after which filter with collected dispersion aerosol is destroyed. Periodic irradiation is carried out after time intervals equal to duration of microorganisms development. Note that temperature and relative humidity of air medium in immediate vicinity from surface of elements of dwelling modules of space stations are preliminary measured, zones of elements surfaces with temperature not exceeding temperature of drop point are fixed, map of such zones for all standard orientations of space station with respect to Sun is composed.
EFFECT: invention allows to ensure reliable protection of space station module constructions against biocorrosion.
1 dwg, 6 tbl
FIELD: medical equipment.
SUBSTANCE: probe comprises a flexible plastic cylinder with an internal channel through which an acoustic wave guide passes freely, a globe-shaped joint tip, and a piezoelectric transducer. The globe-shaped tip is mounted on the tapered distal end of the flexible cylinder. The globe diametre is less than that of the flexible plastic cylinder. The piezoelectric transducer is connected to an electric oscillator.
EFFECT: cleaning and disinfection of flexible endoscopes.
SUBSTANCE: material which is used in the form of a detail, executed by formation by moulding is described, and it represents the biocompatible binding, containing one or several bonds providing addition of calcium or phosphorus, differing that it is exposed to operations of superficial clearing intended for deducing on a surface. This material is preferably used for manufacturing of ventplants or osteal prostheses.
EFFECT: providion of availability on a surface added to binding calcium and phosphorus.
20 cl, 1 ex
FIELD: medical equipment.
SUBSTANCE: device include bath with disinfection solution, in which flexible endoscope is submerged, the working part being immersed into disinfection solution, as well as disinfection solution feed system for washing tool channel of flexible endoscope inner cavity. The disinfection solution feed system has detachable socket, which is put on distal end of flexible endoscope, its outlet tube is fastened on pump suction inlet, and pump discharge outlet leads through a filter to nozzles, fixed on the bath side walls. Coil spring, freely disposed all along inside the tool channel, is joined by its distal end to piezoelectric cell, which is electrically connected to generator.
EFFECT: increase in quality of flexible endoscopes cleaning and disinfection.
5 cl, 1 dwg
FIELD: disinfecting of products.
SUBSTANCE: disinfecting and/or warming device has vapor unit for eliminating microorganisms at surface of solid product, in particular, solid food product. Vapor unit has at least one passage for vapor and opening being adjacent to cavity where water vapor jet is applied under pressure through passage for vapor. Water vapor released from opening, is driven into oscillation at frequency, preferably sonic frequency, determined by cavity. Vapor unit has external part, internal wall of which par defines external wall to let vapor in, and internal part, which forms external wall of passage for vapor and limits opening. Mentioned cavity is made adjacent to mentioned opening.
EFFECT: efficient elimination of microorganisms at surface of product without usage of too high warmth.
14 cl, 6 dwg