SU1110497A1 - Apparatus for applying coatings on particles in fluidized bed - Google Patents

Abstract

APPARATUS FOR DRAWING COATINGS ON PARTICLES IN THE BOILER LAYER, containing a vertically installed hollow body with a pipe for supplying a liquefying gas, a tool, a tasopacial distributor grid and a gas flow separator tube above it, which is designed with a design for a gas flow device, which is designed to create a gas distributor with a gas flow separator, which is designed to create a gas diffuser and a gas flow separator located above it in order to create a gas diffuser with a purpose gas dispenser with a gas distributor and a gas flow separator located above it, with the aim of drawing a grid, with a gas flow separator, with the aim of drawing a grid, with a gas flow separator, in a design, with a view to drawing a gas flow, there is a pattern for the flow of gas, which is designed with a design to create a grille and a gas flow separator gas flow, which is located in the housing, with the aim of drawing a grille and a gas flow separator above it, which is designed to create a gas flow device, with the aim of drawing a grid, and a design for the flow of the liquefying gas; coating and intensifying the deposition process; a gas flow separator tube is made in the form of a truncated cone-diffuser facing the gas distribution grid with a smaller base, the diameter of which is which is equal to or greater than 1-10% of the diameter of the pipe for supplying the fluidizing gas, and the angle of taper of the truncated cone-diffu (Lzor is 10-25 °. co .1

Description

one

FIELD OF THE INVENTION The invention relates to the medical, food and chemical industry, namely to devices designed for coating particles in a fluidized bed.

A fluidized bed apparatus is known, comprising a housing, a gas distribution grill, a coating nozzle (3.

The design of the apparatus due to the introduction into the working chamber of the apparatus of various separators of the flow-reducing agent allows to significantly intensify the mixing of the tablets in the nozzle area, however, it does not provide a smooth, focused tablet and, moreover, requires the use of enhanced-strength tablets, since in the area of the nozzle the translation mc into flowing mode, which negatively affects the quality of the coating and the integrity of the tablets themselves,

Closest to the invention is an apparatus for coating particles in a fluidized bed, containing a vertically mounted hollow body with a pipe for supplying a fluidizing gas, a spraying device located in the body, a gas distribution grid and a gas flow separator tube 2 located above it,

However, insufficiently effective boiling of the layer of tablets, leading to local emissions of tablets over the entire cross section of the apparatus and the absence of intensive mixing of the tablets in the whole volume of the apparatus, does not allow to obtain a high-quality and uniform coating. In addition, a jamming effect occurs in the lower part of the working chamber of the apparatus, since the cross-sectional area of the peripheral part of the apparatus in the lower part of the working chamber is much smaller than the area at the periphery of the upper part. The occurrence of this effect is promoted by the backwater of the waiting agent entering from below through the gas distribution grid. This unit is sophisticated in production: a separator tube consists of two hollow cones connected by lower bases. It is possible that the coating solution and tablets adhere to the heated surface of the separator tube, which leads to a decrease in the yield of the Il.ri-oHoro product. Have agggchrgtt

10497g

low efficiency and productivity due to deficiencies in the hydrodynamics of the particle layer, as well as poor quality of the coating obtained, 5 due to the agglomeration of tablets. The purpose of the invention is to improve the quality of the coating and intensify the coating process.

This goal is achieved by the fact that in an apparatus for coating particles in a fluidized bed containing a vertically installed hollow body with a pipe for supplying a liquefying gas, a spraying device located in a housing, a gas distribution grid and a gas flow separator located above it, the latter is made in the form of a truncated cone-diffuser, 20 facing the gas distribution grid with a smaller base, the diameter of which is equal to or greater by 1-10% of the diameter of the pipe for supplying the liquefying gas, and l conicity of the truncated cone-diffuser is 10-25. The drawing shows an apparatus for coating particles in a fluidized bed, a profile axial section.

The apparatus contains a vertically installed hollow body 1 with a cylindrical tube 2 for supplying a fluidizing gas, an atomizing device 3 placed in the body 1, a gas distribution grid 4 and a separator 6 of a gas flow 6 arranged in the form of a truncated cone diffuser facing the holders 5 to the gas distribution grid 4 with a smaller base | diameter, whose diameter is equal to or greater than 1-10% of the diameter of pipe 2 for supplying a fluidizing gas, and the angle of taper c of a truncated cone-diffuser is 10-25 °.

The hollow body I consists of a cylindrical shell 7 and a console chamber 8, fastened with a flange connection 9.

The conical chamber 8 is made of two conical shells 10 and 11 connected by a weld seam.

The upper shell 10 has a taper knot & 5, and the bottom shell 10 is an angle of 50 °.

The distance between the lower cooling cone-diffuser and the gas distribution grid A is 110-180 mm and is adjustable with screws 12.

An apparatus for coating particles in a fluidized bed operates as follows.

Particles to be coated with polymer are loaded into the conical chamber 8. Include fan and calorie-. fer (not shown to supply heated liquefying times. The velocity flow of the liquefying gas passes through the cylindrical tube 2 from below, penetrates the gas distribution grid 4 and enters the layer of particles. The gas flow lifts the fixed layer of particles into suspension and carries away the separator 6 Due to the expansion of the cross section of the cone-diffuser, the particles lose their initial velocity and, deviating from the center of the flow, are carried into the peripheral zone of the apparatus, the passage of the annular channel between the conical chamber 8 and the distribution tube Ithel 6. The exhaust gas rises Ipokidaet apparatus.

Particles of material located in the peripheral zone of the apparatus, between the xnussm diffuser and conical shells 10 and 11 of the apparatus, under the influence of gravity and suction ejection effect move down to the grate 4. At the interface of the dense layer of particles and the ascending gas flow a cylindrical surface under the separator tube 6, due to the intense ejection effect, the particles are sucked in by the gas flow and the cycle of motion is repeated. After establishing a targeted circulation of particles in the working volume of the apparatus and deciding the desired temperature in the layer, the dosing pump (not shown) is supplied with a film-forming composition (usually a polymer solution), which enters the layer through the distributor 3. The particles are irrigated in a film-forming composition an upward flow of gas and particles, where intense heat and mass transfer takes place between the gas and the solid phase. The process of film formation on the particles occurs simultaneously with the removal of the polymer solvent from their surface. The final drying of the coating on the particles occurs in the peripheral zone - between the cone-diffuser and the conical shell of the apparatus body. The particle coating operation proceeds continuously and ends when a predetermined amount of coating material is supplied. The coating process is completed by drying the particles.

and their unloading.

In the proposed apparatus, a uniform and targeted movement of particles in the fluidized bed occurs both in the nozzle zone and in the

periphery of the apparatus, which allows to obtain a high-quality coating with a high yield of the finished product. Intensification of the process for nystatin tablets) coating is reduced with

3.3 hours to 2 hours

The proposed apparatus is simple. By design and its metal content is reduced.

Ability to coat

on particles, for example tablets, of lower strength than in the apparatus according to Wurster.

The application of the proposed apparatus allows to obtain protective coatings.

high quality from aqueous solutions of polymers. In tab. 1 shows comparative data on the performance of the apparatus, the outputs and the quality of the finished product obtained in the known and proposed apparatus.

The performance of the proposed apparatus exceeds the performance of the known apparatus by 12 kg / h. This is due to the slow movement of the tablets in the known apparatus by the formation of stagnant zones in it and the sticking of tablets wetted to the heated separator tube, which prevents an increase in the supply of swelling solution. These factors significantly affect the quality of the finished product (multiple disruption of the shell from the tablets, uneven coating, and lack of presentation. The use of the proposed apparatus allows obtaining a high-quality coating. The comparative characteristics of the fluidized bed apparatus and the coatings of the tablets obtained in them)

93.1

60

Famous

99.6

60

Proposed

Annual operating costs of the consumer when using the basic (well-known) and new means of labor (the proposed apparatus per 500 Statenatin FS tablets of 500 thousand U, covered with a shell

8.2 Bad 3.3 18.2

Poor movement of the tablets and along the jerking of the solution onto the separator tube, as well as the formation of agglomerates of tablets was noted. As a result, the destruction of the agglomerates on the tablets is chipped.

99.5 Good 2.0 30.0

Table 2 production loan

493.2

14795

870

15828

524-72 651, 2 № 25 3581.6 3847

1 173-81 5000 No. 50 32223 30000

Continued table. 2

120

3596

211.4

1004

30120 1617.2

Claims (1)

PARTICLE COATING APPARATUS IN A BOILING LAYER, comprising a vertically mounted hollow body with a pipe for supplying a fluidizing gas, a sawing device located in the body, a Distribution grating and a gas flow separator tube located above it, characterized in that, in order to improve the quality of the coating and intensification of the application process, the gas flow separator tube is made in the form of a truncated '.. cone-diffuser facing the gas distribution grid with a smaller base, the diameter of which equal to or greater by 1-10% of the diameter of the pipe for supplying a fluidizing gas, and the angle § of the conicity of the truncated diffuser cone is 10–25 °. > I