RU2426576C1 - Solids desublimator - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to desublimation and may be used in chemistry and pharmaceutics to make fine- and ultra-dispersed materials in minor volumes of products. Proposed solids desublimator comprises two desublimators with openings to feed vapor of product to be desublimator and cold carrier gas that are provided with vapor and gas distributing chambers with grids and sublimators, horizontal mixing chamber and finished product separation units. Mixing chamber is divided into sections by horizontal baffles with height not exceeding half the height of the chamber. Odd baffles are arranged at chamber bottom while even baffles are mounted atop the chamber. All walls and baffles of said chamber are perforated. Chamber bottom perforation represents alternating zones confined by baffle arranged at the bottom and having even number of zones while that confined by baffle made atop the chamber has odd number of zones. Odd zones have clear area of (0.25-10)% while that of even zones is one and a half or two times greater.

EFFECT: reduced sticking to desublimator walls, higher yield of finished product.

3 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to desublimation technology and can be used in the chemical and pharmaceutical industries to obtain a mixture of fine and ultrafine materials in small volumes of the product.

BACKGROUND

A device for fractional desublimation of solids from a mixture of gas with vapors [application Germany 3730747, B01D 10011, publ. in BI No. 20 dated 03.30.1989]. The device is a cylinder-conical apparatus, in the lower part of which there are nozzles for supplying steam of a freeze-dried product. These nozzles are located parallel to the axis of the apparatus. There is another row of nozzles for supplying cold gas mounted on the side wall of the apparatus. Nozzles placed on the side wall of the device are inclined to the axis of the device at an angle (0.17-0.75) π radians. The device is equipped with an additional apparatus or unit for separating solid desublimated particles and gas flow.

The disadvantage of this device is the inability to obtain a mixture of finely and ultrafine materials in small volumes of the product.

Closest to the alleged invention in technical essence and the achieved result, i.e. the prototype is a device for desublimation of solids [RF patent No. 2368414, publ. in BI No. 27 dated 09/27/2009], which includes two desublimators with openings for supplying steam of a desublimated product and cold carrier gas, equipped with steam and gas distribution chambers with gratings and sublimators, units for separating the finished product and a horizontal mixing chamber, while the lower part of the chamber is the truncated part of the cylinder or cone, and the upper one is made in the form of a box of variable section, and the ratio of the areas of maximum and minimum sections is 1.25-2.

The disadvantage of the prototype is the possibility of sticking desublimated product on the walls of the apparatus, which leads to a decrease in the yield of the finished product to 85%.

SUMMARY OF THE INVENTION

The inventive task was to create a device for desublimation of solids, which would reduce the sticking of the desublimated product on the walls of the apparatus and thereby increase the yield of the finished product to 95%.

The problem is achieved in that in a device for desublimation of solids, including two desublimators with holes for supplying steam of a desublimated product and cold carrier gas, equipped with steam and gas distribution chambers with gratings and sublimators, including a horizontal mixing chamber and knots for separating the finished product, the mixing chamber is divided on the section with vertical partitions not exceeding half the height of the chamber, while the odd partitions are installed at the bottom of the chamber, and the even ones at the top and The chamber’s membranes and partitions are perforated, while the bottom of the chamber is perforated in the form of successive zones, and the section ending with a partition located at the bottom has an even number of zones, and the section ending with a partition located at the top has an odd number of zones, with odd zones have a living cross section (0.25 ÷ 10)%, and even ones - one and a half to two times larger.

DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION

Figure 1 presents a front view of a device for desublimation of solids.

Figure 2 presents the side view of the device and the separation device of the finished product, including a filter and a collector of the finished product.

Figure 3 presents a horizontal section of the mixing chamber BB and a vertical section of the mixing chamber BB.

The device for desublimation of solids contains two sublimators 1, 2, two steam and gas distribution chambers with gratings 3, 4 and two desublimators 5, 6, connected tangentially by their upper parts to the lower part of the mixing chamber 7, located horizontally, as well as a device for separating the finished product, including filter 12 and the finished product collector 13. The mixing chamber is divided into sections by vertical partitions 8, 9, not exceeding half the height of the section, the walls of the mixing chamber and partitions are perforated, and perforation days and the camera is made in the form of successive zones, and the section ending with a partition located at the bottom has an even number of zones, and the section ending with a partition located at the top has an odd number of zones, and the odd zones 10 have a live section (0.25 ÷ 10)%, and even 11 - one and a half to two times more.

The device operates as follows.

For example, phthalic anhydride and benzoic acid, respectively, are loaded into sublimators 1, 2. The resulting vapor of phthalic anhydride and benzoic acid enters the gas distribution chambers 3 and 4. Next, the vapor of the corresponding substances enters the desublimators 5, 6. The vapor of phthalic anhydride and benzoic acid is mixed with a cooling agent (air). As a result, phthalic anhydride is obtained at the exit from the desublimator 5, and benzoic acid is obtained at the exit from the desublimator 6.

The consumption of cold air is 3.2 m ³ / h. The particle size of phthalic anhydride and benzoic acid at the outlet of the corresponding desublimators was (5-12) microns and (10-27) microns, respectively. The temperature of the gas-solid particle flows at the outlet of the desublimators 5, 6 is about 31 ° C. Next, the flows of gas-solid particles are introduced tangentially into the lower part of the mixing chamber 7. There is a preliminary mixing of desublimated products. The final mixing is carried out when the gas-solid particles flow in the horizontal section of the mixing chamber due to the turbulization of the flow obtained by moving along surfaces having successively alternating zones 10, 11, with different perforations. The flow of gas-solid particles goes around the baffles 8, 9. The resulting mixture is discharged from the mixing chamber and enters the filter 12 and the finished product collector 13.

The yield of the finished product was determined as follows.

The product was removed from the collection of the finished product and weighed, the material was collected from the walls of the mixing chamber and also weighed. The fraction of material remaining in the mixing chamber was (4-5)% of the total mass of the obtained product. Thus, the yield of the finished product was not lower than 95%.

Claims (1)

A device for desublimation of solids, including two desublimators with openings for supplying steam of a desublimated product and cold carrier gas, equipped with steam and gas distribution chambers with gratings and sublimators, a horizontal mixing chamber and units for separating the finished product, characterized in that the mixing chamber is divided into sections by vertical partitions not exceeding half the height of the chamber, while the odd partitions are installed at the bottom of the chamber, and the even ones are installed at the top, all the walls of the chamber and partitions are per oriented, the perforation of the bottom of the chamber is made in the form of successive zones, and the section ending with a partition located at the bottom has an even number of zones, and the section ending with a partition located at the top has an odd number of zones, odd zones have a living cross section of 0.25 ÷ 10%, and even - one and a half to two times more.

Images