Continuous method of production of granulated sodium percarbonate with stabilizing coating and the device for its realization

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

 

The invention relates to the chemical industry and can be used to obtain oxygen-containing bleaching products on the basis of percarbonate sodium, used also as a component of synthetic detergents (CMC).

Percarbonate sodium (hereinafter CRC) connection milestone both during storage and when using it as a component of the CMC, especially in conditions of high temperature, humidity and in the presence of aluminosilicate CMC components.

The main factors causing the loss of active oxygen in peroxisome are, along with high temperature and humidity, primarily the presence of heavy metals (in the form of salts and oxides), falling into particles peroxysalts of feedstock in the synthesis process or components of the CMC. Therefore, the main criterion for chemical stability of PKN and other peroxisome is maintaining the highest possible content of active oxygen (AK) during storage in the form of an individual product, and the composition of the CMC.

Use in detergent compositions of peroxisome coated, especially PKN, has acquired great importance in recent years, from the point of view of environmental safety in connection with the increased use in detergents more aggressive components such as silicates (zeal the t and others), the effects of which are generally compensated for by applying to the surface of the particles peroxisome covering reagent (encapsulation) from 5 to 12% weight/weight.

It should be noted that the chemical stability is not the only requirement for bleaching means on the basis of peroxisome. For example, they should also have good solubility in cold water, sufficient mechanical strength, compatibility with the basic components of CMC on a bulk mass, ensuring the homogeneity of the composition, excluding its delamination and clumping during storage and transport.

Sources of information on the synthesis of stable peroxisome (especially PKN) indicate that the main ways of solving this problem is to stabilize the product of various technological methods and using various chemical products (organic and/or polymeric compounds, aqueous solutions of neutral salts of alkaline or alkaline earth metals, acids and the like) depending on the requirements of consumer properties of the final product.

Known continuous way to obtain granulated oxygenated bleach on the basis of the CRC, namely that the product of the interaction of aqueous solutions of hydrogen peroxide and soda with an Addendum is receiving stabilizers are mixed with Securom in the form of granules PKN, followed by drying in a fluidized bed, part of the dried granules separated by particle size, are selected as the target product granules with a size of 0.1-1.0 mm to obtain the target product, and the rest returned to the process as rature (RU # 2164215, CL 01 In 15/10, publ. 20.03.2001,).

It is also known a device for implementing this method, contains one United system reagent supply, mixer, dryer, fluidized bed, and means for separating particles into fractions, line removal of one of the factions which is the drain line of the target product, and the mixer is in communication with the fluidized bed dryer in the zone of entry of the wet granules and in the zone of the conclusion of dry granules in the classifier (RU # 2164215, CL 01 In 15/10, publ. 20.03.2001,).

The specified method and the device allow you to get granular PKN with a high initial content of AK, but with a lack of stability.

Known method of stabilizing PKN applying the coating material sprayed onto the particles of the aqueous solution covering the reagent mixing in the mixer and subsequent drying in a fluidized layer, and the coating is applied during the many aisles of processed particles through the mixer and separate dryer (RU # 2137704, IPC 01 15/10, publ. 1999).

Closest to the proposed invention is a continuous method of obtaining granulated PC is with a stabilizing coating, namely, that the product of the interaction of aqueous solutions of hydrogen peroxide and baking soda are mixed simultaneously with Securom in the form of granules PKN and with a solution of a stabilizing agent, followed by drying in a fluidized bed, a portion of the dried granules separated by particle size selected particles, the average fraction (mostly 0.1-1.0 mm)as the target product, and the rest returned to the process as rature (utility model RU # 27586, CL 01 In 15/10, publ. 2002)

Closest to the proposed invention is also a device for implementing the described method, containing the delivery system of the original reactants, the reactor, a screw mixer, a fluidized bed dryer provided with a mixer in the zone of entry of the wet granules and in the zone of the conclusion of dry granules, means for separating granules into fractions, line removal of one of the factions which is the drain line of the target product, the delivery system stabilizing agent is provided with a mixer in the zone of entry of the wet granules in the dryer (see ibid.).

Known methods and devices do not deliver the desired quality of product (sufficient stability during storage due to the imperfections of the technology of applying a stabilizing coating material on the particles of peroxisome. The original particles or granules of proxool who represent a capillary-porous body, which contain in their volume up to 65% of the free space in the form of channels, capillaries and cavities filled with atmospheric air, flue gases used in the formation of particles, and moisture, which amount in capillary-porous body is characterized as the specific moisture content. When applying the coating material by known methods and with known devices covering material does not form a strong and solid layer (shell) of applying to the original product fine particles, and create the same in essence and structure of the capillary-porous coating. Therefore, to achieve air-tightness of the coating layer must reach a 5.0-12% weight/weight, which in turn leads to an increase in the total volume of pores and capillaries of the particles, the expansion of the range of granulometric composition and the change in the direction of increasing the bulk density of the obtained product. Because the resulting coating layer is non-uniform moisture through the pores of the coating material supplied to the inside of the particles (granules), is connected with the capillary moisture and together with the oxygen present in the ambient air and flue gases, triggers and accelerates the decomposition of particles peroxysalts. If the coating material forms part of a continuous homogeneous layer, when the temperature of the air and combustion gases inside the kernel, expand, the destruction of the granules and rupture of the coating layer and formed through the cracks is contact with the external moisture, which in result leads to decomposition of the product.

The objective of the invention is to increase the stability of the granulated PKN with a stabilizing coating.

This task is solved in that in a method of producing granulated PKN with a stabilizing coating, which consists in the fact that the product of the interaction of aqueous solutions of hydrogen peroxide and soda is brought into contact with Securom in the form of granules PKN, followed by drying in a fluidized bed, a portion of the dried granules are divided by the size of the particles for separation of the granules of the target fraction, and the rest returned to the process as reture, according to the invention a solution of a stabilizing agent is brought into contact with the granules of the target fraction, the process is carried out in vacuum with subsequent stepwise pressure increasing to excess negative not less than 95 kPa or naturally, after then the obtained product is dried in a fluidized bed, and the granules of the target fraction and a solution of a stabilizing agent previously subjected to separate the vacuum. In addition, the vacuum on all operations is carried out at a residual pressure of not more than 25 kPa. In addition, the vacuum pellet target fraction and solution article is militaryuse agent shall exercise at least 40 minutes. In addition, the concentration of the original solution of the stabilizing agent is 3-20 wt.%. In addition, a solution of a stabilizing agent is used in an amount of 0.09-0,265 volume of the processed granules of the target fraction.

This technical result is also achieved by the fact that the known device for obtaining granulated PKN with a stabilizing coating containing connected in series with the supply system of reagents, one or two mixer directly connected to the fluidized bed dryer, a means for separating the particles into fractions, line removal of one of the factions which is the drain line of the target product, and the delivery system solution of a stabilizing agent, mixers communicated with the dryer in the zone of introduction of the wet granules and in the zone of the conclusion of dry granules in a classifier, according to the invention contains an additional mixer and fluidized bed dryer, vacuum system and at least three storage capacity for pellet target faction, communicated with the drain line of the target fraction from the classifier, and the solution supply stabilizing agent includes at least two measuring containers for the solution of a stabilizing agent, an additional mixer inlet communicated with the storage tanks for the pellet target fraction and the volumetric capacities for the of astora stabilizing agent and is connected to the vacuum system, and the output is communicated with an additional fluidized bed dryer, storage capacity for pellet target fraction, volumetric capacity for the solution of the stabilizing agent is connected to the vacuum system and with the atmosphere, and the additional mixer includes three functional camera: the mixing chamber, compression chamber and the transport chamber, the mixing chamber has inlet channels for feeding pellets and solution of a stabilizing agent and through an outlet passage in the form of a confuser, and sealed spring-loaded valve connected to the compression chamber and contains a screw conveyor, consisting of an equal length sections, the first section includes a screw with a uniform pitch, the middle section includes screw with a uniform pitch and may have notches on each blade, located on a circle through 90°the last section includes a screw with differential decreasing step, the transport chamber is under compression chamber and contains a screw conveyor consisting of two sections, the first section occupies most of the length of the screw conveyor and includes a screw with a uniform pitch, the second section is located in front of the input window for the dryer and includes a rectangular blade, the length of which is not more than 0.8 width of the input window for more with the Shilka. In addition, the gas distribution grid for more dryer is installed with a slope of up to 8° to the horizontal.

Figure 1 shows the General setup diagram; figure 2 - scheme of an additional mixer.

The device has connected in series: the delivery system initial reagents, including capacity 1 for hydrogen peroxide solution, the container 2 to a solution of baking soda and two reactor 3 (one shown)connected by lines 4 and 5 with tanks 1 and 2, two mixer 6 (one shown)adjacent to the opposite walls of the dryer 7 and communicated with her every two Windows: to enter reture and enter the wet granules in the dryer. The reactor 3 is installed directly on the mixer 6, which represent the two screw conveyors are equipped with engines with an adjustable number of revolutions of the screws rotating in opposite directions. Dryer 7 has a rectangular cross-section, equipped with a gas grill neprovalnoy type, cross-section which decreases as the promotion of the product to the discharge area of the granules. The dryer 7 is connected through line 8 with means for separating granules size classifier 9, the middle line is the line of withdrawal of the granules of the target fraction and is connected with the storage tanks 10, 11 and 12. The device also includes a measuring vessel 13 and 14 for a solution of a hundred is ilizarova agent and additional dryer 15 fluidized bed of cylindrical shape, installed vertically and equipped with a gas grill neprovalnoy type, cross-section which decreases as the promotion of the product to the discharge area through the pipe 16 and which is installed with an inclination of up to 8° to the horizontal. Dryer 15 through line 17 is connected to the generator 18. Directly to the dryer 15 is adjacent to an additional mixer 19 which is connected with it through the entrance window 20. The mixer 19 includes a horizontal mixing chamber 21 from the inlet 22 to the input of the granules of the target fraction and 23 for feeding a solution of a stabilizing agent and gradually tapering in the form of a confusor output channel 24, sealed spring-loaded valve 25, is made with possibility, with a little effort, the release of wet granules through the channel 24 in the compression chamber 26. The mixing chamber 21 is equipped with a screw conveyor 27, which consists of three equal length sections, the first section is located under the input channels 22 and 23 and provided with a screw with a uniform pitch; the second (middle) section provided with a screw with a uniform pitch, which may have recesses in the shape of a square or circle on each pass made half the height from the top of the axis of the screw to the top edge of the screw and located on a circle through 90°; the third and final section contains a screw with decreasing differential W is d each subsequent round, and under compression chamber 26 posted by transport chamber 28, provided with a screw conveyor 29, and the greatest part of its length provided with a screw with a uniform pitch, which is output from the chamber 28 moves in a rectangular horizontally oriented vanes in the amount of 4-6 pieces, arranged around the axis, the length of which is equal to not more than 0.8 the width of the entrance window 20 of the dryer 15. Screw conveyors 27 and 29 are equipped with engines with an adjustable number of revolutions of the screw. The dryer 7 is equipped with a host of dust collection, including the cascade AIDS cleaning of flue gases from dust - cyclones 30 and 31 connected to the dryer 7 through line 32 and lines 33 and 34 to return the captured dust from PKN to the mixer 6; furnace gases from the loops 30 and 31 are passed through a wet scrubbing system 35 and released into the atmosphere. Dryer 15 is connected to the node of the dust along the line 36 through line 32. The classifier 9 is a two-stage vibrating screen, the average fraction of which on line 37 is directed into the storage tank 10, 11 and 12 through the shut-off valves 38, 39 and 40, the large fraction of granules on line 41 is fed to the mill 42 and after grinding through the hopper 43 through line 44 and 32 through the cyclones 30 and 31, further along the line 33 and 34 is returned to the mixer 6; the small fraction of granules on line 45 collected in the hopper 46 and line 47 returns in Esteli 6 in the same way, as the grinding. Storage tanks 10, 11 and 12 through the dispensers 48, 49 and 50 by line 51 is connected to the input 22 of the mixer 19; a measuring vessel 13 and 14 through the feeders 52 and 53 to line 54 is connected to the input 23 of the mixer 19 and through the shutoff valves 55 and 56 on line 57 - host-preparation of a solution of a stabilizing agent 58. In addition, storage tanks 10, 11, 12, a measuring vessel 13, 14 and the mixing chamber 21 of the mixer 19 through shut-off valves 59, 60, 61, 62, 63 and 64 through line 65 is connected to the vacuum system 66 and the storage capacitor 10, 11, 12 and the measuring vessel 13 and 14 through the shutoff valves 67, 68, 69, 70, 71, line 72 connected to the atmosphere. The device is also equipped with measuring instruments: aquametro 73, mounted on the line 65; vacuumation 74 installed in the mixing chamber 21 of the mixer 19; gauges 75, 76, 77 mounted on the storage containers 10, 11 and 12, which are also equipped with weighing devices 78, 79 and 80; gauges 81 and 82 mounted on the measuring tank 13 and 14, which are also equipped with sensors for liquid media 83 and 84. Management measurement and control is carried out from a control panel (not shown).

The initial position of the device before you begin:

On line 37 shut-off valve 38 is open and the shut-off valves 39 and 40 are closed.

On line 51 dispensers 48, 49 and 50 are closed.

On line 54 dispensers 52 and 53 are closed./p>

On line 65 shut-off valves 59, 60, 61, 62, 63 and 64 are closed.

On line 72 shutoff valves 67, 68, 69, 70 and 71 are open.

On node 58 begin the process of preparing a stabilizing solution.

Granulated PKN with the specified fractional composition and external stabilization was obtained as follows: in the reactor 3 through line 4 and 5 are served prepared in accordance with the technological requirements of the aqueous solutions of hydrogen peroxide and soda. Obtained by mixing the reaction mass is fed to the mixer 6 via the fill-valve film. In the mixers 6 reaction mass is distributed over the surface of the seed particles (Remora) and wets on the surface of the crushed and pulverized particles PKN. The mixing process takes no more than about 45 seconds, after which the wet granules through the inlet are shown in the dryer 7 and get on the gas grill, pre-filled granules PKN to a height estimated weighted layer and blown hot flue gases supplied from the heat source. In the dehydration process in a fluidized bed granules are transported by a stream of hot flue gas to the zone of production of dried pellets, one of which from the dryer 7 is returned to the mixer 6, and the other part on line 8 enters the classifier 9. From the intermediate part of classific the Torah 9 average fraction of granules on line 37 is sent to the holding tank 10, the content of which is controlled by the weight measuring device 78. When the preset volume filling capacity 10 granules of the target fraction of the flow of granules is directed to the following cumulative container 11 by opening shut-off valve 39. After closing the shut-off valve 38 to the supply line 37 and 67 on the message line with the atmosphere 72 filled with a solution of a stabilizing agent selected concentration (3-20 wt.%, mostly 8-15 wt.%) alternately or simultaneously measuring vessel 13 and/or 14 to line 57 of site preparation 58, controlling the filling of tanks with gauges 83 and/or 84. When the preset amount of filling of the measuring containers with a solution of a stabilizing agent cease its supply and shut off valves 55, 56, 70 and 71. Include a vacuum system 66, opened on line 65 shut-off valves 59, 62, 63 and 64 for carrying out preparation phase (vacuum) pellets in the storage capacitor 10 and a solution of a stabilizing agent in a volumetric tank 13 and/or 14. In the process of vacuum at a residual pressure of not more than 25,0 kPa, mainly when a 4.0 to 8.0 kPa, from the inner core cavity of the treated granules are derived flue gases, air, a portion of capillary moisture and impurities of heavy metals (in the form of salts and oxides), got into granules PKN feedstock in the synthesis process, and the stabilizing solution is Ghent escaped with simultaneous partial evaporation of moisture in the range of 1.0 to 3.0% of the total volume of the solution for the whole cycle phase of training. The duration of the phase of preparation of granules and solution of a stabilizing agent lasts until the complete evacuation of the cumulative and measured capacities. Start dosing pellets from the storage tank 10, or 11, or 12 and a solution of the stabilizing agent from the measuring tank 13 and/or 14 into the mixing chamber 21 of the mixer 19 is carried out not less than 40 minutes after the beginning of the preparation phase (vacuum). The flow components in the mixer 19 are in the ratio of 0.09-0,265 volume of a solution of a stabilizing agent to the volume of the granules LTU.

In the period of time between the beginning of the preparation phase and the beginning of the dosing of the components in the mixer 19 is prepared to work the dryer 15, the filling gas grill granules PKN or balls of another inert material, such as ceramics and the like, with a diameter of 1.5-2.5 mm in height estimated weighted layer with filler as capillary-porous system for uniform distribution over the entire area of the grating heated air coming from under-grid space and discharged by the fan through the pipe 17 through the heat source 18, and as an additional movable gas distribution grid to sever the links between clumps of wet granules PKN coming from the mixer 19. Include actuators screw conveyors 27 and 29 in the mixer 19. In a given the time begin simultaneous feeding of pellets PKN, the last phase of preparation, for example, from the storage tank 10 through the spout 48 through line 51 to the input 22 and a solution of the stabilizing agent from the measuring vessel 13 through the spout 52 through line 54 to the input 23 of the mixing chamber 21 of the mixer 19. When hit granules PKN into the mixing chamber 21 together with a solution of a stabilizing agent to the mass of the granules becomes heavily impregnated with the solution. The very mass of granules is capillary-porous system model of capillary-porous body consisting of spherical particles of sufficiently small diameter and representing the body, riddled with capillaries and capillary tubes with the curve axis, which coincides with the progress of spherical particles (granules), where capillaries have a triangular cross-section, and the area of their cross section is experiencing the correct alternate changes from a maximum to a minimum. Each granule is a capillary-porous body and also absorbs any wetting her fluid, regardless of its chemical composition. When this occurs swelling of the surface layer of the granules and its partial dissolution, and the dissolution rate of the humidified PKN is controlled by the specified time granules PKN in the mixing chamber 21, which is the application of a stabilizing agent in the process of mechanical mixing mA is si in vacuum, and the notches made on the blades in the middle section of the screw 27, promote better mixing due to the repayment of part of the weight of the wet granules through the notches in the area of the previous turn of the screw.

Next, the wet granules are transported to the output channel 24, in front of which are concentrated in the confused space and then removed in the form of a cylindrically shaped mass from the channel 24, pressing the spring-loaded valve 25, without depressurization of the mixing chamber 21, and hence the system as a whole, because the densified mass of wet granules itself is a sealing element in the output channel 24. Then the mass of the pellet passes through the compression chamber 26, where, after its withdrawal from the zone of the vacuum there is a sharp jump of external pressure over the entire area of the surface of each pellet, because the pressure in the compression chamber 26 is always equal to the pressure in the dryer 15, which is atmospheric or excessive negative not less than 95 kPa. A pressure surge promotes uniform distribution of the solution of a stabilizing agent not only on the surface of the granules, but also the introduction of a solution into the depths of the surface layer to a depth of swelling and its fixation at the expense of the mutual adsorption between the core material granules and solution of a stabilizing agent, with simultaneous preservation of capillary channels under vacuo the Ohm, that allows to avoid internal stress granules under sharp fluctuations of temperature and humidity, and also leads to a drastic reduction of its hygroscopicity, which in turn contributes to the preservation for a long time of active oxygen on the source level in the compositions of the CMC.

Further, the weight of the wet pellet hits the screw conveyor 29, which delivers it to the input window 20 and a horizontally oriented blades throws on the gas grill for more dryer 15, dehydrated in a fluidized bed, and due to the flow of hot air from under-grid space and the inclination of the lattice up to 8° horizontal dehydrated granules are moved to the unloading area and through the pipe 16 is poured into the prepared packing containers. Moreover, the increase of the tilt angle distribution of the lattice more than 8° not advisable, as this will increase the velocity of the granules to the discharge area and the residence time of the granules in the dryer will be insufficient to achieve a desired moisture content in the granules of the final product.

At the initial emptying of the storage tank 10 ends the filling of the storage tank 11 and through line 37 to the flow of pellets are directed into the accumulation tank 12. Then close the shutoff valve 39 in line 37 and 68 on line 72, after h is th accumulation tank 11 is connected to the vacuum system 66 by opening shut-off valve 60 on line 65 for holding the phase of preparation of the granules in the storage tank 11. After emptying of the storage tank 10 open the dispenser 49, then close the dispenser 48 and the valve 59.

Then open the shutoff valve 67 to relieve vacuum in the internal cavity of the vessel 10, which is left in the reserve mode.

The same procedure is performed when emptying one of the measured capacities, for example, 13. As the filling in a volumetric tank 13 and 14 in the initial stages occurred, either alternately or simultaneously on the prepare phase (vacuum) solution of a stabilizing agent they were delivered at the same time, after emptying the measuring vessel 13 first open the dispenser 53 to line 54, then close the dispenser 52 and the valve 62 on lines 65 and then open the shutoff valve 70 to relieve vacuum in the inner cavity of the measuring vessel 13 through the line 72 and the valve 55 on line 57. Then, from site preparation 58 again fill the tank 13 through line 57, after filling closes the shutoff valves 55 and 70, again connected to the vacuum system 66 by opening shut-off valve 62 on lines 65 and for a solution of the stabilizing agent in the vessel 13 begins the prepare phase.

Thus, the cycle of operation of storage tanks 10, 11 and 12 and the measuring tank 13 and 14 with the performance of technological operations in each of them is repeated, i.e. the continuity of the process of the external article is stabilizing the solution of granules PKN solution of a stabilizing agent by using a minimal set of components and discrete techniques, with the deletion of the synchronous execution of parallel and identical cyclic operations, using the dynamics of a process with elements of positional adjustment.

The stability of the samples was estimated by the method of EATING 10005 by comparing the content of AK in the original and stabilized materials before and after the test in the climatic chamber, by mixing with the zeolite in a ratio of 50/50 and aging at a temperature of 32°C and a relative humidity of 80% within 48 hours.

The content of AK in the samples was determined by the method EAT 07278.

Table 1 presents the test results of samples PKN obtained using the proposed method and devices using various stabilizing agents, and in each example the average test result of 10 samples.

Table 2 presents comparative qualitative characteristics of PKN stabilized according to the invention and a known manner by spraying a solution of coating material in a fluidized bed. As a coating material was used a solution of sodium sulfate.

Table 1
№ p/pThe stabilizing agentThe concentration of the camera is liter. solution, %The volumetric ratio of the particles PKN and solution of a stabilizing agentThe residual pressure in the vacuum, kPaWt. the share of AK prior to coating, %Wt. the share of AK in the product after exposure to the climate. the camera, %.Stability after coating, %Bulk density, g/DM3
The source materialAfter coating
12345678910
1.Na2SO430,18413,9113,7666,812151203
2.Na2SO4100,215813,9113,8869,9212151210
3.Na2[B(OH)4]100,1651514,1014,0069,0012101206
4.Na2SO4200,2016 at 13.8413,7870,3812151265
5.Na2SO4150,2658at 13.8413,7671,8312151248
6.Na2SO4+MgSO45+0,50,175513,9113,9070,1612151205
7.Na2SO4+MgSO410+0,50,09813,88at 13.8468,7312151211
8.Na2SO4200,14813,8613,6167,712151308
9.Na2SO4+MgSO415+0,50,2251013,9113,8271,1412151252
10.Na2[B(OH)4]50,1502514,1013,9568,312101208

The table is 2


Indicators


Source PKN
PKN coated
According to the inventionAccording to the method
The Mac. the share of active oxygen, % (average)of 13.8 to 14.113,61-14,011,8-12,3
The average particle size, microns650-950660-980670-1100
Wt. the proportion of sodium sulfate, %-0,9-2,73,6-4,5
Wt. fraction of moisture, %≈3,00,8-1,00,8-1,0
Bulk density, g/DM312141200-12101210-1310
Stability, %56-6166-7253-56

1. A method of obtaining a granulated percarbonate sodium with a stabilizing coating, which consists in the fact that the product of the interaction of aqueous solutions of hydrogen peroxide and soda is brought into contact with Securom in the form of granules PKN, followed by drying in a fluidized bed, a portion of the dried granules are divided by the size of the particles for separation of the granules of the target fraction, and the rest returned to the process as reture, characterized in that the solution of the stabilizing agent is brought into contact with the gra is Olami target fraction, the process is carried out in vacuum with subsequent stepwise pressure increasing to excess negative not less than 95 kPa or atmospheric, after which the obtained product is dried in a fluidized bed, and the granules of the target fraction and a solution of a stabilizing agent previously subjected to separate the vacuum.

2. The method according to claim 1, characterized in that the vacuum at all operations is carried out at a residual pressure of not more than 25 kPa.

3. The method according to claim 2, characterized in that the degassing of the granules of the target fraction and a solution of a stabilizing agent to carry out at least 40 minutes

4. The method according to claim 1, characterized in that the concentration of the original solution of the stabilizing agent is 3-20 wt.%.

5. The method according to claim 1, characterized in that the solution of a stabilizing agent is used in an amount of 0.09-0,265 volume of the processed granules of the target fraction.

6. Apparatus for producing granulated percarbonate sodium with a stabilizing coating containing connected in series with the supply system of reagents, one or two mixer directly connected to the fluidized bed dryer, a means for separating the particles into fractions, line removal of one of the factions which is the drain line of the target product, and the delivery system solution of a stabilizing agent, mixers communicated with boot the zone input moist granules and in the zone of the conclusion of dry granules in the classifier, characterized in that it contains an additional mixer and fluidized bed dryer, vacuum system and at least three of the storage tank communicated with the drain line of the target fraction from the classifier, and the solution supply stabilizing agent includes at least two measuring capacity with additional mixer inlet communicated with the storage tank and measuring tank for a solution of the stabilizing agent and is connected to the vacuum system, and the output with additional fluidized bed dryer, tank and measuring tank connected to the vacuum system and with the atmosphere, and the additional mixer includes three functional camera: the mixing chamber, compression chamber and the transport chamber, the mixing chamber has two input channels for the supply of granules and solution of a stabilizing agent and via the output channel in the form of a confuser, sealed spring-loaded valve, is connected with the compression chamber and contains a screw conveyor, consisting of three equal length sections, the first and the middle section includes a screw with a uniform pitch, the last section includes a screw with differential decreasing step, the transport chamber is under compression chamber and contains a screw conveyor consisting of two sections, the first is s is s occupies a major part of the length of the conveyor and includes screw with a uniform pitch, the second section is located opposite the entrance window to the dryer and includes a rectangular blade, the length of which is not more than 0.8 width of the input window for the dryers.

7. The device according to claim 6, characterized in that the mixing chamber screw the middle section of the screw conveyor has on each blade in the notch located on a circle through 90°.

8. The device according to claim 6, characterized in that the gas distribution grid for more dryer is installed with a slope of up to 8° to the horizontal.



 

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4 cl, 2 tbl, 6 ex

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The invention relates to a method of stabilizing insoluble colorant containing hypochlorite compositions intended for bleaching fabrics and hard surfaces

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: food industry; production of oxygen-containing bleaching agents and synthetic detergents.

SUBSTANCE: the invention is intended for a chemical industry and may be used at production of oxygen-containing bleaching agents and synthetic detergents. The method provides, that solid particles of the paroxysmal are exposed to vacuumizing at a residual pressure of no more than 13.33 kPa, mainly at 0.67÷8.5 kPa with simultaneous heating up to 55°C, up to 40÷50° C. Then it is treated with a noble gas at atmospheric or excessive pressure of no more than 10 kPa. The mass share of active oxygen (in mass %) is no less than 14.00, stability of the finished product is no less than 59,92 %.

EFFECT: the invention ensures a high stability of alkali metals peroxisalts.

4 cl, 1 dwg, 1 tbl

FIELD: chemical industry; a method and a device of alkali metals peroxysalts stabilization.

SUBSTANCE: the invention is intended for a chemical industry and may be used at production of oxygen-containing bleaching agents and synthetic detergents. In the vacuum drier 3 supplied with a rake-type rabble 10 and a weight-measuring device 12, the main original material is supplied from a reserve tank 1. Then it is vacuumized simultaneously with the solution of a coating material located in a measuring container 17, connected by lines 21, 22 and 13 with the device of a dryer 3 vacuumizing. Then mix the main original material with the solute of the coating material at a residual pressure of no more than 13.33 kPa. Increase the pressure in the vacuum drier 3 up to the atmospheric pressure or exceeding it by no more than 10 kPa spasmodically by an air supply from a source 28. The produced product is exposed to a vacuum drying up to the required moisture, making control of the moisture content by a change of the weight of the dryer 3 contents with the help of the weight-measuring device 12. Stability of the finished product is 59.0-69.0 %, consumption of the coating material - 0.9-1.8 mass %, the share of the active oxygen - 13.8-14.4 mass %.

EFFECT: the invention ensures production of oxygen-containing bleaching agents and synthetic detergents.

10 cl, 1 dwg, 2 tbl

FIELD: chemical industry.

SUBSTANCE: the invention is intended for a chemical industry and may be used in production of bleaching agents and washing agent, household chemical goods. The reactor (1) is fed with soda ash, for example in the form of a solution, through sleeves(5) and a link (7) and hydrogen peroxide solution through a link (6). The sleeves (5)allow to move the reactor (1) along the auger of the mixer (2). Humid granules of sodium percarbonate produced in the mixer (2) are removed through a connecting pipe (9) into a dryer (3) supplied with a gas-distributing lattice (10). One part of the dried granules through a connecting pipe (8) is fed back into the mixer (2), and other part through link (15) is fed into the qualifier (4). A commercial fraction of sodium percarbonate is removed through link (16) into a pneumatic classifier (20). The fine fraction through link (22) and through the cyclone separator (13) and link (14) is fed back into the mixer. The coarse fractions of sodium percarbonate from the qualifier (4) is fed through link (17) into the grinding machine (18). Crushed sodium percarbonate is mixed with the fine fractions and through the cyclone separator (13) and through link (14) is fed back into the mixer (2). The invention allows to decrease the share of a dust faction down to 0.10 - 0.63 % and losses at drying, to increase the share of active oxygen up to 13.91-14.01 % and stability of the finished product.

EFFECT: the invention ensures reduction of the share of a dust faction up to 0.10 - 0.63 % and losses at drying, an increase of the share of active oxygen up to 13.91-14.01 % and stability of the finished product.

4 cl, 1 dwg, 1 tbl

The invention relates to the chemical industry, in particular to household chemicals, and can be used in the manufacture of percarbonate sodium and other chemical products, where the process of synthesis is combined with granulation synthesized product

The invention relates to a method for nadali and more specifically to percarbonate sodium and thus obtained the sodium percarbonate

The invention relates to percarbonate sodium-containing detergent compositions

The invention relates to a method of synthesis of peroxocarbonates alkali metals, which are a valuable, environmentally friendly oxidants with a wide range of practical applications

Granulator // 2271246

FIELD: wood-working industry.

SUBSTANCE: granulator comprises housing with the charging hopper, rotating surface with grooves, matrix, and knives. The grooves are made by the multi-entrance winding. The cross-section of the grooves decreases in the direction of movement of the material to be granulated. The matrix is secured to the end of the winding, and its outer side is in a contact with the knives secured to the housing. The number of openings in the matrix is equal to that of the grooves.

EFFECT: simplified structure.

2 dwg

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