Method of producing granular sodium percarbonate
SUBSTANCE: invention can be used in production of detergents and bleaching agents. Granular sodium percarbonate is obtained through granulation in a fluidised bed which contains sodium percarbonate particles, into which aqueous hydrogen peroxide solution and aqueous sodium carbonate solution are sprayed through at least one multi-component nozzle with external mixing, with simultaneous evaporation of water. The sodium carbonate solution additionally contains sodium carbonate and/or sodium percarbonate in suspended form. Before feeding into the multi-component nozzle, the sodium carbonate solution is passed through a mechanical disperser to disperse solid substances using shearing force created between the stator and the rotor.
EFFECT: invention enables to avoid clogging of multi-component nozzles and return dust-like sodium percarbonate, separated from the stream going out of the fluidised gas layer, into the granulation process.
5 cl, 2 ex
The present invention relates to a method for producing granulated percarbonate sodium by (durastically) granulation in the fluidized bed with a possibility of sodium carbonate and/or percarbonate sodium in suspended form in the spray nozzle without the risk of clogging.
Percarbonate sodium finds wide application as having bleaching action of the component in detergents and cleaning agents. To apply for these purposes, percarbonate sodium must have in the composition of detergents sufficient stability (resistance) during storage, because otherwise, when the storage containing detergents can result in the loss of active oxygen loss as a result percarbonate sodium its bleaching action. Percarbonate sodium sensitive to contact with moisture under the influence of which it decomposes in the composition of the detergents with the loss of active oxygen. Therefore, for the manufacture of detergents or cleaning agents percarbonate sodium is usually used in the form of particles in the shell, which protects covered with it particles of percarbonate sodium from moisture. The use of granulated percarbonate sodium can cover its particles are effective shell already when the flow rate is considerable quantities forming its material.
Granulated percarbonate sodium with a smooth surface of the granules, especially suitable for coating the shell, you can get known from WO 95/06615 way granulation in the fluidized bed. Upon receipt of the granulated percarbonate sodium this way, an aqueous solution of hydrogen peroxide and aqueous sodium carbonate solution is sprayed through a multicomponent nozzle with external mixing in containing particles of percarbonate sodium fluidized bed with simultaneous evaporation of water. In sputtered multicomponent nozzle jet conical mixing of the hydrogen peroxide solution and sodium carbonate solution are formed droplets of the solution percarbonate sodium, usually saturated. In the fluidized bed these droplets collide with particles of percarbonate sodium, which precipitates from solution percarbonate sodium and with the surfaces of which are made with these aqueous solutions of the water evaporates under the effect of siraudeau gas fed to create a fluidized bed. However, the disadvantage of this known method consists in the necessity of evaporation of relatively large quantities of water. In addition, due to the abrasion of the particles in the fluidized bed, and also because of the undesirable drying of the droplets prior to their collision with the particles percarbonate sodium is formed is Lavigny percarbonate sodium, out of the fluidized bed siraudin gas.
Formed with the exhaust from the fluidized bed gas pulverized percarbonate sodium does not meet the requirements for its application in the detergent composition, and for this reason it far back in the production cycle, adding in the process of preparation of a solution of sodium carbonate. Similarly to the process cycle can be returned and pulverized percarbonate sodium with other stages of the technological process, for example, from the stage of the coating or from the pneumatic supply system of particles percarbonate sodium. However, a significant part associated pulverized percarbonate sodium peroxide is lost through decomposition in alkaline solution of sodium carbonate.
In EP 0787682 A1 to reduce the amount of water evaporated was asked to serve in a multicomponent nozzle is not the solution, and a suspension of sodium carbonate. Together with a suspension of sodium carbonate or spray air additionally you can also submit crystalline percarbonate sodium. However, the disadvantage described in EP 0787682 A1 method is a rapid clogging of nozzles already after a short time of their work, as it was established in experiments in connection with the filing in EB is Pascoe patent office of opposition to grant of patent EP 0787682 B1.
Given the above, in this area there remains a need to develop a method of producing granulated percarbonate sodium by granulation in the fluidized bed with the possibility of filing herewith sodium carbonate and in suspended form in the spray nozzle without the risk of clogging. Equally there is also a need return pulverized percarbonate sodium in the production cycle without loss thus associated in percarbonate sodium peroxide for use in the process of obtaining the desired granulated percarbonate sodium.
With the invention it was found that the above problems can be solved using the method of producing granulated percarbonate sodium by granulation in containing particles of percarbonate sodium fluidized bed, in which via at least one multi-component nozzle with external mixing spray an aqueous solution of hydrogen peroxide and an aqueous solution of sodium carbonate with simultaneous evaporation of water, and the solution of sodium carbonate, optionally containing sodium carbonate and/or percarbonate sodium in suspended form, before serving in multi-component nozzle is passed through a dispersant for dispersing solids.
Upon receipt of the pellet is consistent of percarbonate sodium proposed in the invention method using an aqueous solution of hydrogen peroxide, preferably the hydrogen peroxide is from 30 to 75 wt.%, particularly preferably from 40 to 70 wt.%. Additionally, the hydrogen peroxide solution may also contain a stabilizing percarbonate sodium, respectively, the content of active oxygen supplements. As such enhance the stability of percarbonate sodium additives, it is preferable to use the alkali metal silicates, primarily silicate, magnesium salts, stannate, pyrophosphates, polyphosphates, and chelating agents from the group hydroxycarbonic acids, aminocarbonyl acids, aminophosphonic acids, phosphonocarboxylate acids and hydroxyphosphonic acids, as well as their salts with alkali metals, ammonium and magnesium salts.
Upon receipt of the granulated percarbonate sodium proposed in the invention method is used, in addition, an aqueous solution of sodium carbonate, optionally containing sodium carbonate, percarbonate sodium or both of these substances in suspended form. The number of suspended sodium carbonate, respectively percarbonate sodium, you can choose within a wide range, provided that the slurry remains fluid and retains the ability to pumping. Additionally aqueous solution of sodium carbonate may also contain stabilizing percarbonate sodium additives is, preferably one of these in the previous paragraph additives. In the sodium carbonate solution containing the suspended percarbonate sodium coming from the next stage of the coating or from the pneumatic supply system coated particles percarbonate sodium, in this case, there may be some amount submitted with this percarbonate sodium forming the shell material.
Upon receipt of the granulated percarbonate sodium proposed in the invention by way of an aqueous solution of sodium carbonate, optionally containing sodium carbonate, percarbonate sodium or both of these substances in suspended form, prior to being fed into the spray nozzle is passed through a dispersant for dispersing solids. For use as a dispersant suitable for all devices that provide uniform distribution of particles of sodium carbonate, respectively percarbonate sodium in the sodium carbonate solution with the simultaneous destruction of agglomerates of particles of sodium carbonate or particles percarbonate sodium. As an example, suitable for use in these purposes, the dispersant can be called ultrasonic dispersers. Preferably, however, use dispersers mechanical action, based on, for example, on the impact of the var is girugamesh materials or the creation of shear forces. Particularly preferred dispersant in which the shear force applied to the suspension, is created between the rotor and stator. As examples of the dispersing agents of this type that can be used to obtain granulated percarbonate sodium proposed in the invention method can be called stream dispersant (dispersant continuous action) constructive series Ultra-Turrax®and Dispax®manufactured by IKA.
The parameters of the dispersant and his work should preferably be such that it ensures the destruction or fragmentation present in the slurry of agglomerates, the diameter of which more than a third higher than the minimum pipe size used in the multi-component nozzle. When the flow of the suspension through the Central channel of the multi-component nozzles specified minimum pipe size corresponds to the minimum diameter of the Central channel. When applying the same suspension through the annular channel multi-component nozzles specified minimum pipe size corresponds to the minimum width of the annular gap that forms this annular channel.
The sodium carbonate solution with suspended particles of sodium carbonate and/or percarbonate sodium preferably continuously pass through the disperser and immediately after exit and who to serve in multi-component nozzle. Filtered through the dispersant slurry can simultaneously serve several multicomponent nozzles.
In one of the preferred embodiments of the invention, the dispersant is dispersed solid sodium carbonate and/or solid percarbonate sodium in an aqueous solution of sodium carbonate. This solid material is fed into the sodium carbonate solution and was dispersed in this solution in the same apparatus. As examples of the dispersing agents suitable for use in this embodiment of the invention, can be called inline dispersers constructive series MHD manufactured by IKA.
The sodium carbonate solution may further comprise a stabilizing percarbonate sodium supplements, which you can use the same additives as in the hydrogen peroxide solution.
Both of the solution, i.e. the hydrogen peroxide solution and passed through a disperser of the sodium carbonate solution with suspended particles of sodium carbonate and/or percarbonate sodium, served in one or more multi-component nozzles passing through separate channels, the output of which is an external mixture of both of these solutions in a spray nozzle jet is conical. In the spray nozzle, respectively, in each spray nozzle predpochtitelnei this additionally fed through another it provided for the channel of the spray gas. The corresponding multi-component nozzle with one or two channels for the spray gas is known from WO 95/06615 and EP 0787682 A1. As a sputtering gas, it is preferable to use the air.
Quantitative consumption of hydrogen peroxide solution and quantitative consumption of the sodium carbonate solution with suspended particles of sodium carbonate and/or percarbonate sodium is preferable to choose such that the molar ratio between sodium carbonate and hydrogen peroxide was preferably from 1:1.4 to 1:1,7, particularly preferably from 1:1.5 to 1:1,65. The specified molar ratio refers to the total number of dissolved and suspended sodium carbonate, but excluding suspended percarbonate sodium. The temperature of both solutions should preferably be from 20 to 70°C.
The hydrogen peroxide solution and sodium carbonate solution with suspended particles of sodium carbonate and/or percarbonate sodium multicomponent spray nozzle in containing particles of percarbonate sodium fluidized bed. The commonly used multi-component nozzles can be placed at this over the fluidized bed or within the fluidized bed. To shorten the way that the formed droplets must pass to particle fluidized bed, and in beanie spray drying droplets of multicomponent nozzles preferably within the fluidized bed.
Fluidized bed create and maintain in the fluidized state by filing siraudeau gas, which also intensifies the evaporation of water. Siaosi gas preferably be submitted in a fluidized bed temperature in the range from 120 to 500°C., particularly preferably from 200 to 500°C., especially from 300 to 500°C. Temperature and flow siraudeau gas is chosen so as to allow evaporation of a predominant part of all made with solutions of water. Temperature and flow siraudeau gas is preferable to choose those which allow to maintain the temperature in the fluidized bed in the range from 40 to 95°C., particularly preferably from 50 to 80°C., especially from 60 to 80°C.
Upon receipt of the granulated percarbonate sodium proposed in the invention method, the above solutions can be sprayed in a fluidized bed in a continuous or periodic mode. Preferably also continuously spraying two solutions in a fluidized bed and continuously to take away from him the obtained granulate. The obtained granulate is preferably selected from the fluidized bed sorting through the discharge device, which allows you to return the granule diameter is too small back in the fluidized bed.
In the initial phase of granulation in pseudowire the second layer of the first form of small particles, employees centres granulometry, which are then sprayed with the above solutions. As such centers granulometry it is preferable to use particles percarbonate sodium that are smaller in size, which must be obtained granulate. Continuous granulation in the fluidized bed therein to form granules should always be new centers of granulometry. Such centers granulometry can be formed within the fluidized bed as a result of abrasion of the formed granules or crushing. More preferably, however, feeding centers granulometry in solid form in a fluidized bed from the outside to control the rate of formation of centers granulometry and thus particle size distribution of the obtained granules.
In the process of granulation in the fluidized bed from him siraudin gas are ejected fine, dust-like particles percarbonate sodium. Such particles can be separated from the exhaust flow of the fluidized bed gas with suitable for this purpose device or separators, such as scrubbers, filters or cyclones. Such particles after their separation in solid form in the form of dust from the exhaust of the fluidized bed gas is preferably fully or partially podawa the ü in the dispersant and dispersing in a solution of sodium carbonate, supplied in multi-component nozzle.
The advantage of the invention method before known from EP 0787682 A1 method lies in the possibility of continuous receipt of granulated percarbonate sodium for a long period of time without danger of clogging of the multi-component nozzle. In addition, we offer in the invention, the solution enables more uniform in comparison with the known from EP 0787682 A1 way to spray containing solids solution of sodium carbonate, as these particles do not get stuck in the hole of the spray nozzle, the spray of which jet is conical eliminated thereby the uneven distribution of solid particles. The associated positive effect is the ability to achieve nearly complete conversion of hydrogen peroxide in percarbonate sodium when using hydrogen peroxide in a smaller excess.
In the variant with return pulverized particles percarbonate sodium, separated from the flow of exhaust from the fluidized bed gas disperser proposed in the invention method allows you to return this pulverized percarbonate sodium in the production cycle without loss contained in the bound form of hydrogen peroxide. This enables you to convert large quantities use the th of hydrogen peroxide in the product granulated percarbonate sodium homogeneous quality. Return pulverized percarbonate sodium in the production cycle is not detrimental to the quality of the obtained granulated percarbonate sodium.
Example 1: the Dispersion of the sodium carbonate solution with suspended particles percarbonate sodium with and without the use of dispersant
30%by weight soda solution was applied with a flow rate of 300 l/h through a flow disperser type MHD 2000/5 company IKA in the three-component jet model 0/56 S3 firm Schlick and sprayed without spraying gas. In the dispersant double row dispersing the working body of the rotor-stator type with width of the gap between the teeth 3 mm soda solution was dispersively pulverized percarbonate sodium with an average particle size of 45 μm in the amount of 80-150 kg/h Spray nozzle worked during 4 h without clogging and formed uniformly sprayed a jet of conical shape.
In a comparative experiment, instead of dispersing the working body used to not having a dispersing effect suspendisse working body. After a short period of time due to partial clogging of the gap junction channel injector was beginning to form irregular, intermittent spray jet conical shape.
Example 2: Return pulverized percarbonate in the process Gras is ulali in the fluidized bed
Powdered percarbonate sodium with an average particle size of 45 μm, separated from the stream of exhaust gas of an industrial plant for producing granulated percarbonate sodium, dispersively with a flow rate of 100 kg/h as described in example 1, the equipment 30%by weight soda solution, supplied with a flow rate of 280 l/h, and then filed in a three-component nozzle of the industrial installation. Through this three-component nozzle using air as the spray gas in a fluidized bed created in the industrial setting, was spraying the resulting suspension, and 44%by mass hydrogen peroxide solution with a flow rate of 90 l/h after a 3-day period three-component nozzle no its clogging was not observed. According to the results of the analysis of quantitative (material) balance setup it was found that more than 50% returned to the process cycle pulverized percarbonate sodium joined the obtained granulated percarbonate sodium.
Return pulverized percarbonate sodium cycle had no effect on the particle size of the obtained granulated percarbonate sodium and abrasion resistance.
1. A method of obtaining a granulated percarbonate sodium by granulation in containing particles Parker is onata sodium fluidized bed, in which via at least one multi-component nozzle with external mixing spray an aqueous solution of hydrogen peroxide and an aqueous solution of sodium carbonate with simultaneous evaporation of water, characterized in that the sodium carbonate solution, optionally containing sodium carbonate and/or percarbonate sodium in suspended form, before serving in multi-component nozzle is passed through a dispersant for dispersing solids.
2. The method according to claim 1, characterized in that the dispersant use mechanical action.
3. The method according to claim 2, characterized in that the dispersant to the slurry applied shear force generated between the rotor and stator.
4. The method according to one of claims 1 to 3, characterized in that the dispersant is dispersed solid sodium carbonate and/or solid percarbonate sodium in an aqueous solution of sodium carbonate.
5. The method according to claim 4, characterized in that the exhaust flow from the fluidized bed gas separating percarbonate sodium in the form of dust and separated pulverized percarbonate sodium fully or partially served in the disperser.
SUBSTANCE: sodium percarbonate particles covered by a cladding have a core of sodium percarbonate obtained via fluidised bed granulation. The cladding contains sodium sulphate and sodium carbonate in weight ratio ranging from 95:5 to 75:25 in relative amount of at least 80 wt %.
EFFECT: improved detergent action of sodium percarbonate when used as detergent component with simultaneous increase in stability when stored with detergents.
12 cl, 5 tbl
SUBSTANCE: sodium percarbonate particles are covered by a cladding which contains sodium sulphate in form of a high-temperature phase of sodium sulphate and/or in form of a high-temperature phase of a double salt of formula Na4(SO4)1+n(CO3)1-n, where n is a number ranging from 0 to 0.5.
EFFECT: high stability during storage.
8 cl, 4 tbl, 3 ex
SUBSTANCE: sodium percarbonate particles are covered by a cladding which contains anhydrous sodium sulphate in amount of 70-99.8 wt % and sodium borate in amount of 0.2-20 wt % and where said cladding accounts for 1-10% of the total weight of one particle of sodium percarbonate.
EFFECT: high stability during storage when using sodium percarbonate particles as a component of detergent and cleaning agents.
9 cl, 2 tbl, 2 ex
SUBSTANCE: invention relates to sodium percarbonate particles. Essence of invention: described are particles of sodium percarbonate, provided with coating and consisting of main particles of sodium percarbonate, surrounded with at least one layer of coating, possessing long storage stability, expressed as amount of released heat at 40°C, measured after 12-week long storage at temperature 40°C, which constitutes less than 5 mcW/g. Subject of invention also are sodium percarbonate particles, provide with coating and consisting of main particles of sodium percarbonate, surrounded with at least, one layer of coating, possessing long storage stability, expressed as preservation of available oxygen content after 8-week long storage at temperature 55°C, which constitutes at least 70%. Also subject of invention are method of said sodium percarbonate particles production and application of said particles in detergent compositions as bleach, and detergent compositions, containing described sodium percarbonate paprticles.
EFFECT: creation of sodium percarbonate particles possessing increased long storage stability.
14 cl, 2 ex, 4 dwg
SUBSTANCE: invention refers to sodium percarbonate particles. According to the invention the coated sodium percarbonate particles possessing the inner shell layer including as basic component at least one inorganic hydrate-forming salt and outer shell layer including alkali metal thiosulphate, alkali-earth metal thiosulphate and/or ammonium thiosulphate are described. The method of such sodium percarbonate particles preparation and application of these particles as bleaching agent in detergents and cleansers are also the subjects of an invention.
EFFECT: increasing of stability of sodium percarbonate particles in detergents and cleansers during storage.
23 cl, 4 dwg, 4 tbl
SUBSTANCE: invention concerns chemical bleaches applied in cleansers and detergents. Invention claims sodium percarbonate granules with coating of high storage endurance, including a) core obtained by dispersion granulation in pseudoliquefied layer with sodium percarbonate as main component, b) internal coating layer with non-organic hydrate-forming salt as main component, selected out of group including sodium sulfate, sodium carbonate, sodium bicarbonate, magnesium sulfate and mixes or mixed salts of these compounds, and c) outer coating layer with surfactant containing sulfate or sulfonate groups in the form of alkaline metal, alkaline-earth of ammonium salt, as main component.
EFFECT: enhanced storage endurance, high stability and active oxygen content in percarbonate granules.
22 cl, 1 ex
FIELD: technological process.
SUBSTANCE: invention may be used in all fields of engineering, in which application of disinfectant solutions is required, in particular, in medicine, food industry and others. Method of disinfectant preparation includes supply of water solution of alkaline metal carbonate in anode chamber of diaphragm electrochemical cell with cylindrical coaxial electrodes and coaxial ceramic ultra-filtering diaphragm, supply of fresh water in cathode chamber of the same cell and disinfectant drain from anode chamber. Solution of alkaline metal carbonate and water are supplied in anode and cathode chambers of cell with counter-flow. Process is carried out during current conduction via diaphragm mainly with alkaline metal ions. Disinfectant prepared by treatment of water solution of alkaline metal carbonate with concentration of 0.2-2 g/l in anode chamber of electrochemical diaphragm cell with coaxial electrodes and coaxial ultra-filtering ceramic diaphragm, contains peroxide compounds that are in metastable condition and has pH of 6-7.
EFFECT: invention allows to prepare efficient disinfectant that does not contain chlorine, in required quantity at site of consumption with reduction of costs for its manufacturing and usage.
6 cl, 1 dwg, 4 ex
FIELD: chemical industry; production of sodium percarbonate and other chemical products.
SUBSTANCE: the invention is pertaining to the field of chemical industry and may be used in production of sodium percarbonate (SPC) and other chemical products, where the synthesis process is combined with the synthesized product granulation. The granulated sodium percarbonate is produced by the steady growing-up of the products of interaction of the stabilized water solutions of the soda and hydrogen dioxide on the inoculation particles-granules. To chokes give torrents of The streams of the stabilized water solutions of soda and hydrogen dioxide are fed into the reactors at keeping the time of their interaction from 5 up to 21 sec and concentration of the sodium carbonate and the hydrogen dioxide in the ratio of 1 : 1.45-1.57. The produced reaction mass in the form of a solution is fed into the mixers-granulators, where it is distributed along the surface of the inoculation particles of sodium percarbonate, moisten and saturate them within 12-25 seconds up to achieving the average humidity of 6-12 mass %. Then the wet granules are brought out into the drying room on the gas-distributing grate, on which there is a slotted clearance with the gas-feeding channel, formed as a semi-circled groove on the gas-distribution grate and the upper end of the inclined chute. The feeding of the heated flue-gases is exercised under the gas-distribution grate through the gas duct, in which there is an erected septum being the prolongation of the upper wall of the channel and separating up to 6 % of total volume of the fed flue-gases, which are coming in through the channel with adjustment of the speed of their passage through the slotted clearance into the drying room, where they form a gas curtain in the form of the semi-tabernacle, in which the dried granules are classified according to their flying speeds in such a manner, that granules with the diameter less than the preset dimension, for example 500 microns, are carried out by the two equivolumetric streams formed by splitter made in the form of a triangular prism, to the windows and are def into the mixers-granulators as the recycle for a following cycle of granularity, and the granules with the diameter exceeding the preset lower limit, for example - 500 microns and above, fall through the gaseous curtain and on the inclined chute through the outlet window get into the classifier for the final classification according to the high limit of the preset fractionized composition of the final product, for example 800 microns. From the intermediate part of the classifier the granules the preset fraction are delivered for storage. The production output of the granules of the preset fraction, for example, 500-800 microns, is up to 99 %, the bulk weight is 1093-1138 kg/m3, the contents of the active oxygen is - 13.94-14.1 %, stability is 55.91-56.83 %. The invention allows production of sodium percarbonate with the preset range of the composition of the granules without reduction of productivity of the installation.
EFFECT: the invention ensures production of sodium percarbonate with the preset range of the composition of the granules without reduction of productivity of the installation.
9 cl, 2 tbl, 4 dwg
FIELD: chemical industry; methods and devices for production of sodium percarbonate with a stabilizing coating.
SUBSTANCE: the invention is pertinent to the field of chemical industry, in particular, to the method and the device for production of sodium percarbonate with a stabilizing coating and may be used in the production of the oxygen-containing bleaches made on the basis of sodium percarbonate (SPC), which is also applied as a component of synthetic washing agents (SWA). The initial solutions of hydrogen peroxide and sodium are brought in contact with the recycle made in the form of the SPC granules in the mixer, dry in the boiling layer in the driers, a part of the granules are fed into the classifier for separation by the granules size for separation of the granules of the target fraction, the remaining part of the granules are directed back in the mixer in the capacity of the recycle. The target fraction of the SPC granules is in series collected in the storage containers and subjected to vacuumization. Simultaneously the stabilizing agent is subjected to the vacuumization in the measuring containers. The so treated SPC granules and the solution of the stabilizing agent are brought in contact in the additional mixer first at the residual pressure of no more than 25 kPa with the following heighten of the pressure up to no less than 95 kPa or to the atmospheric pressure and dry in the additional drying machine of the boiling layer. At that the finish product stability achieves to 66.0-72.0 %, consumption of the coating material - to 0.9-2.8 weight/weight %, the contents of the active oxygen - 13.8-14.1 mass %. The technical result is the increased stability of the granulated sodium percarbonate with the stabilizing coating.
EFFECT: the invention ensures the increased stability of the granulated sodium percarbonate with the stabilizing coating.
8 cl, 2 tbl, 2 dwg
FIELD: chemical industry.
SUBSTANCE: proposed method includes delivery of aqueous solution of hydrogen peroxide and soda from reservoirs of 1 and 2 to reactor 3. Reaction mass thus obtained is delivered to double-screw mixer 6 communicated with drier 7. Part of dried granules is returned from drier 7 to mixer 6 and other part is directed to classifier 8; fraction at size of particles from 0.1 to 1.00 mm is directed from intermediate part of said classifier to storage reservoir 9 for target fraction granules. Then, granules are fed to vacuum drier in the scope of no more than 50% of its inner volume. Solution preparation unit 37 is used for preparation of aqueous solution of stabilizing agent- sodium, sodium sulfate, sodium carbonate, sodium silicate or their mixtures. Concentration of stabilizing agent solution is 5-15 mass-% and volume is 0.215-0.235 of volume of granules. Vacuum drier 11 and measuring reservoir 10 are evacuated simultaneously to residual pressure not exceeding 13.33 kPa. Granules are evacuated at heating to 55°C and are mixed with stabilizing agent solution first in vacuum followed by jumpwise rise of pressure to atmospheric level or to excessive pressure of 10 kPa; procedure is continued for 0.5-1.0 min. Then vacuum drying is performed at constant or periodic mixing. Moisture content of finished product doe not exceed 1.05% at stability of 59.93-65.74%.
EFFECT: enhanced efficiency.
12 cl, 1 dwg, 1 tbl
FIELD: process engineering.
SUBSTANCE: invention relates to production of carbamide granules with sphericity of over 75% and residual moisture content equal to or lower that 0.5% in jet layer apparatus. Fluid containing carbamide is fed into carbamide solid particle flow in apparatus with jet layer. Said carbamide solid particle flow is supported by gas flow fed from behind. Gas flow is fed into apparatus working chamber 8 approximately horizontally and turned therein. Carbamide particle-gas flow 15 is fed to jets 2 in working chamber 8 from lateral side. Note here that carbamide particle-gas flow rate between has jet entry at working chamber 8 and injection zone is increased by adjustable gas nozzles. Fluid containing carbamide is injected in area of higher density 22 on carbamide particle surfaces, dried and separated and granulated in gas flow.
EFFECT: dust-free granules, good flowability, soft surface.
16 cl, 4 ex, 1 dwg
FIELD: machine building.
SUBSTANCE: installation for production of granulated products consists of vertical cylinder case, of gas distributing grid, of grid of boiling layer, of vertical gas supplying branch coaxially installed in this grid, of branch supplying air under grid, of sprayer for sputtering pulp or melt, of branches for supply of disperse material, of branch for granules unloading and of axial gas withdrawing branch. Also, the installation includes coaxial truncated cones, the internal of which is secured on the vertical gas supplying branch and grid of boiling layer, while the external one is attached to the grid of the boiling layer and cylinder case. In an upper part of the installation there is installed a separation zone consisting of three parts: two conic ones and one - cylinder; a stop is installed inside the separating zone; the stop corresponds to two cones; the upper cone has bigger height, while the lower one has lower height; the bases of cones are interconnected.
EFFECT: intensified process of drying, reduced dust carry over, and upgraded quality of product.
FIELD: technological processes.
SUBSTANCE: invention relates to the field of chemical technology and may be used to produce granulated sodium arsenite in processing of reaction mass produced at the stage of alkaline hydrolysis of lewisite. Liquid reaction mass is exposed to continuous convective spraying drying in fluidised bed. Process is carried out at the temperature of layer 70÷150°C and at underpressure of 10÷200 mbar, and nitrogen is used as fluidised and spraying agent.
EFFECT: invention provides for hardware and structurally simple, technologically and ecologically safe process applicable for large-capacity production of granulated sodium arsenite suitable for long-term storage.
3 cl, 1 dwg
FIELD: process engineering.
SUBSTANCE: invention relates to device (10) intended for processing powder materials that incorporates work chamber (16) to process material therein. Device bottom (18) is formed by several overlapping circular guide plates (22-24) arranged one above the other. Circular slots (25, 26) formed there between allow work air to flow there through. At the center of said bottom (18) there is circular-slot-like nozzle (30) with its sprayer can spray fluid in the form of flat jet (44), approximately, parallel to bottom plane.
EFFECT: optimum transfer of powder material particles and material processing.
9 cl, 2 dwg
FIELD: production processes.
SUBSTANCE: invention refers to method of substance granulation in fluidised layer and granulator for its implementation. Method consists in the following: by means of fluidising air fluidised layer of granules of granulated substance which is supplied to fluidised layer in the form of inoculating seeds is formed and substance or liquid for granules growing are continuously supplied to fluidised layer. Fluidising air flow is divided into many flows which are supplied to various zones of fluidised layer with different rate within limits from minimum in first zone, enough for maintaining fluidised layer, to maximum in second zone, required for formation of circular motion, actually, eddy motion of granules of granulated substance in fluidised layer and its maintaining around horizontal axis.
EFFECT: method of granulation in fluidised layer and granulator for its implementation (versions) is described.
10 cl, 6 dwg
SUBSTANCE: invention relates to production of granular calcium chloride, which can be used in communal and road facilities. The method of producing granular calcium chloride involves preparation of a concentrated solution of calcium chloride from evaporated clarified still waste liquid from ammonia-soda production and subsequent dehydration and crystallisation. Non-ionic surfactant is added to the clarified still waste liquid and then evaporated to concentration of calcium chloride of 35-45%, after which it is taken for dehydration and crystallisation in a boiling-spouting drier-granulator. The spouting bed in the drier-granulator is created by a stream of furnace gases, fed through a central inlet at a rate of 50-55 m/s at temperature 700-750°C, and the boiling bed is created by an air stream at temperature 20-60°C, which is fed at a rate of 3-5 m/s.
EFFECT: intensification of the drying process, recycling still waste liquid, obtaining granular calcium chloride.
6 cl, 1 dwg, 1 tbl
SUBSTANCE: invention refers to granulation process in fluid bed of various substances, e.g., carbamide, ammonium nitrate, ammonium chloride and other similar granulated substances. Substance granulation process in fluid bed (F1) involves cooling finishing granules in the second fluid bed (F2). Herewith the same cooling air flow is used consistently for continuous generation and maintenance of cooling (F2) and granulating (F1) fluid beds arranged in tandem relative to the specified running cooling air flow. Granulator for fluid bed granulation includes container-shaped self-supporting structure limiting internal cavity wherein granulation process takes place and there is a partition mounted as a support for granulating fluid bed (F1). Granulator is provided with a plate arranged in the internal cavity of self-supporting structure, spaced under the partition and forming the base being a support for cooling fluid bed (F2), consisting of hot granules produced in granulating fluid bed (F1). The beds are connected through perforated, latticed, mesh or otherwise gas-permeable partition. The internal cavity is equipped with vertical downpipe to pour finished granules from granulating fluid bed (F1) to cooling fluid bed (F2). Under base-forming plate sheet, there are fluidising air feeder and deliverer to the internal cavity of self-supporting structure and cooling and granulating fluid beds forming and maintenance units.
EFFECT: reduced air consumption required to complete granulation process.
7 cl, 2 dwg
FIELD: technological processes.
SUBSTANCE: invention concerns granulation method in fluidised layer for various substances, such as carbamide, ammonium nitrate, ammonium chloride and similar substances viable to granulation. Particularly invention concerns method of granulation in fluidised layer with temperature adjusted by hot air feed, and to granulation plant for implementation of the method. During granulation of a certain substance in fluidised layer at adjustable temperature, finished hot granules are selected from fluidised granulation layer and cooled down in fluidised cooling layer continuously formed and sustained by fluidising air flow. At least a part of fluidising air leaving cooling fluidised layer of finished granules is fed to fluidised granulation layer. Cooling and granulation fluidised layers are positioned in sequence against air flow passing through them. Granulation plant used in the described method includes self-carrying construction with partition serving as support for fluidised granulation layer. Under the partition a step away from it, a base-forming sheet serving as support for fluidised cooling layer is located. Fluidised granulation and cooling layers interface over a perforated, grid, mesh or other gas-permeable partition. Finished granules are poured from fluidised granulation layer into fluidised cooling layer over transition stack. Devices of fluidised air feed and distribution in internal cavity of self-carrying construction are located under base-forming sheet.
EFFECT: reduced total energy expenditure required to maintain fluidised layer temperature at specified level sufficient for optimal granulation process finish.
10 cl, 2 dwg
SUBSTANCE: application contains the description of method of granulating in fluidised bed and obtaining the final granules of certain substance in the so called vertically growing granulating fluidised bed which is formed and maintained by the appropriate flow of fluidising air from which the final granules are poured into the collector under excess pressure and then unloaded from it.
EFFECT: simplification and cost reduction of maintenance of unloading final granules from collector; secure preparation and preservation of monodisperse final granules of specified size.
7 cl, 3 dwg
FIELD: granulating engineering.
SUBSTANCE: device comprises vertical cylindrical housing, gas-distributing grate, vertical gas-supplying branch pipe coaxially secured inside it, tangential gas-supplying branch pipe mounted in the top section of the housing, branch pipe for supplying of dispersed material, and branch pipe for discharging granules. The vertical gas-supplying branch pipe receives the nozzle for spraying pulp or melt. The top section of the housing receives the axial gas-discharging branch pipe provided with a conical funnel and deflector. The tangential gas-supplying branch pipe is connected with the branch pipe for supplying dispersed material. The plane of the exit section of the branch pipe for supplying dispersed material is perpendicular to the axis of the tangential gas-supplying branch pipe. The deflector is made of a rotation body defined by two coaxial conical surfaces, inner surface and outer surface. The device is provided with valve gates to control the process. The valve gates are mounted in the gas-supplying pipe lines.
EFFECT: enhanced efficiency.
FIELD: production of powdery materials.
SUBSTANCE: the invention presents an installation with a fluidized layer and with a complex spray drying and a method of production of the powdery materials dried with the help of a spray drying, whose properties can be varied purposively depending on the application. The installation contains a spraying column, a fluidized layer, a module of a spray drying, one or several of additional spraying or pulverizing nozzles for a liquid component located in a fluidized layer, a batching gear for a powder and a powder returning gear with a fan. The module of a spray drying includes a spraying system consisting of a heated doublet spraying nozzle in which a liquid) component and sputtering air are merged. The installation contains also a dynamic filter integrated in it used for clearing of the gas of from a part of a powder. The spraying column is located above the fluidized layer. The latter for giving direction of motion of the stream of a powder it is supplied with a perforation in Conidur base. The module of a spray drying is located in the spraying column above a fluidized layer. The doublet spraying nozzle is supplied with the coaxially located powder returning gear and an enveloping stream of hot air. The spraying system is made in the form of an integrated module. In the method of production of a powdery material at the first stage the following components are combined: a liquid component, a spraying gas, a powdery material and hot air. The formed powdery product falls on a fluidized later, is caught up, fluidized and transported further. At one or more stages of granulation it is pulverized with an additional liquid component, dried and transported with the fluidized layer to the powder batching gear, from which a part of the powdery material is returned in the process. The invention ensures fast removal of surface moisture, prevention of granules adhesion and production of particles of the given size.
EFFECT: the invention ensures fast removal of surface moisture, prevention of granules adhesion and production of particles of the given size.
14 cl, 2 dwg