RU2229918C2 - Method of desublimation of solid substances and a device for its realization - Google Patents

Abstract

FIELD: chemical and pharmaceutical industries. SUBSTANCE: the invention presents a method of desublimation of solid substances and a device for its realization. The group of inventions is pertinent to desublimation engineering and may be used in chemical and a pharmaceutical industries for production of mixtures of the fine- and ultra-dispersed materials in small volumes of products. Technical result is production of the fine- and ultra-dispersed materials in small volumes of products. Desublimation of solid substances is realized by interaction of a cool gas-carrier with vapors of a desublimated product. At that the separate interaction of the gas-carrier is exercised with vapors of no less than two kinds of desublimated substances till achieving a condition of a supersaturation of vapor-gas mixtures in two desublimators. Then the mixtures are kept in the zone of desublimation till the required particle sizes are reached, and then streams of the gases - solid particles are fed in counter direction to each other and into a mixing chamber, in the lower part of which there are the slit type apertures with guide grooves, where a layer-by-layer mixing of the streams takes place. At that the layers of one stream are directed counter to the layers of another stream at the similar angles to the vertical because on one wall of the mixing chamber the guides are located at the similar angles to an axis of the device in the interval of their values of 30^o-75^o, and the layers of the second stream are directed at variable angles and for the purpose on the opposite wall of the mixing chamber the guides are located at the different angles with their increasing values varying from 30^o up to 75^o. After that the produced mixture is separated for the fine- and ultra-dispersed materials. EFFECT: the invention allows to produce the fine- and ultra-dispersed materials in small volumes of products. 2 cl, 3 dwg, 1 tbl

Description

Technical field

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

State of the art

A known method for producing ultrafine material. The method consists in the following: active gas B is fed into the flow of active gas A through a porous septum and ultrafine particles of reaction products are obtained as a result of the reaction. A device for implementing the analogue method is a cylindrical body with an inner cylinder placed coaxially therein. Between the outer and inner cylinders are annular porous partitions. The walls of the inner cylinder are also porous [Japanese Application 63-23734, 5 B 01 J 12/02. // Inventions of the world, 1994, issue 11, No. 2].

The disadvantage of this method and device for producing ultrafine material is the inability to obtain mixtures of finely and ultrafine materials in small volumes of the product.

Closest to the proposed invention in technical essence and the achieved result, that is, the prototype, is a method for fractional desublimation of solids from a mixture of gas with vapors [Application Germany 3730747, 4 B 01 D 7/00. // Inventions, 1989, 18, No. 20]. The method consists in the fact that cold gas, which comes at a very high speed from the nozzles, collides with a gas mixture with vapor of a desublimated product, which also comes with acceleration from the nozzles. The mixing temperature of the resulting gas mixture with a solid is set by adjusting the amount and temperature of the cold gas so that it lies below the sublimation temperature of the desired solid and above the sublimation temperature of the by-products. To achieve effective mixing, cold gas concentrically collides with a mixture of gas with vapors. The angle between the direction with which the cold gas intersects with the flow of the gas-vapor mixture is (0.17-0.75) π radians. The resulting gas-solid mixture leaves the displacement zone. Moreover, further separation of solid particles from the flow of non-sublimated impurities and gas occurs. A device for implementing the prototype method is a cylindrical apparatus, in the lower part of which are placed nozzles for supplying steam of a desublimated 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 of (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 the prototype method and device for its implementation is the inability to obtain a mixture of finely and ultrafine materials in small volumes of the product.

SUMMARY OF THE INVENTION

The inventive task was to create a method and device for desublimation of solids, which would allow to obtain a mixture of finely and ultrafine materials in small volumes of the product.

The task is achieved in that the desublimation of solids is carried out by the interaction of a cold carrier gas with vapors of a desublimated product, while the gas is separately interacted by carriers with vapors of at least two types of desublimated substances to a state of saturation of gas-vapor mixtures in two desublimators, the mixtures are kept in the zone of desublimation until the required particle sizes are reached, and then gas-solid particles flows, directing the layers towards each other, into the mixing chamber, in the lower part to slotted holes with guides are located, where layer-by-layer mixing of flows takes place, and the layers of one stream are directed to the layers of the oncoming stream at the same angles to the vertical due to the fact that on one wall of the mixing chamber the guides are located at the same angles to the axis of the apparatus in the range of their values 30-75 °, and the layers of the second stream are directed at variable angles, for which the guides on the opposite wall of the mixing chamber are located at different angles increasing from 30 to 75 °, after which they are separated by a radiated mixture of finely and ultrafine materials.

List of drawings

Figure 1 presents a General view of a device for sublimation of solids. Figure 2 presents a view a of the gas distribution chamber of figure 1. Figure 3 presents a diagram of the node input counter flows of gas - solid particles into the mixing chamber.

Information confirming the possibility of carrying out the invention

The device for desublimation of solids contains two desublimators 1, 2, connected by their upper parts to the lower part of the mixing chamber 3. In the lower part of the mixing chamber on the opposite sides, which are connected to the desublimators, there are slotted holes with guides 4 and 5, and on one wall of the chamber, the guides 4 are located at the same constant angles to the axis of the apparatus, in the range of 30-75 °, and on the other wall the guides 5 are located at angles increasing from 30 to 75 ° (see figure 3). Below, the desublimators are connected to steam and gas distribution chambers 6, 7, having cold gas supply fittings 8, 9. Inside the steam and gas distribution chambers, steam supply channels from sublimators 10 and 11 pass through. These channels, as well as the bottom of the steam and gas distribution chamber, are covered with insulation 12.13. In the upper part of the gas distribution chambers there are lattices 14, 15 with holes 16 (Fig. 2). Sublimators 17, 18 are attached to the lower part of the gas and gas distribution chambers, which are equipped with tubes 19, 20 for supplying inert gas to them. Sublimators have electric heating 21, 22 and thermal insulation 23, 24.

The device also contains a filter 25 with a fitting 26 for the exit of the carrier gas and a collector of the finished product 27.

For example, phthalic anhydride and benzoic acid, respectively, are loaded into sublimators 17, 18. Electric heating 21, 22 is turned on and phthalic anhydride and benzoic acid are melted. The temperature in the sublimators is brought to the required level. Inert gas is supplied through the tubes 19, 20 to the sublimators, at the same time cold gas is supplied to the nozzles 8, 9 in the amount of 1.6 m ³ / h, which, passing through the gas-vapor distribution chambers 6, 7, is mixed with the gas-vapor mixture leaving the channels 10, 11 . The temperature of the periodontium mixture is -165 ° C, the temperature of the cold gas is -30 ° C. The vapor flow rate of phthalic anhydride is 8.5 g / h, the vapor flow rate of benzoic acid is 7.2 g / h. The concentration of vapors of phthalic anhydride and benzoic acid at the outlet of channels 10, 11 of the gas distribution chambers is 37.5 and 33.7%, respectively.

As a result of cooling the vapors of desublimated substances, they are saturated and desublimation of fine particles of phthalic anhydride and benzoic acid in desublimators 1, 2. 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 particles flows at the outlet of the desublimators 1, 2 is about 31 ° C. Further, through the guides 4, 5, the gas-solid particles are separated into layers and mixed in the counter mode in the mixing chamber 3. Due to the fact that the inclination of the guides 4, 5 is different, the flows are further twisted, as a result of which the mixing improves. The resulting mixture is discharged into the filter 25, in which solid particles are separated and sent to the finished product collector 27, and the carrier gas is removed through the nozzle 26.

The table shows the results of the analysis of individual samples taken from various sections of the filter surface.

The weight of the sample is 10 mg. The analysis was carried out on a SPECORD - M 40 spectrophotometer.

The proposed method and device for its implementation allow to obtain finely and ultrafine mixtures of high quality, because The effect of high-quality mixing is achieved at a sample level of 10 mg. The effectiveness of the method is also confirmed by the fact that the production of finely and ultrafine particles occurs from stable nuclei of particles with their subsequent growth to the desired size.

Claims (2)

1. The method of desublimation of solids by reacting a cold carrier gas with desublimated vapors and separating the finished product, characterized in that they conduct separate interaction with the cold gas vapors of at least two types of desublimated substances to a state of supersaturation of vapor-gas mixtures, maintain the mixture in the zone of desublimation until the required particle sizes, then the gas-solid particles flows are mixed layer by layer, directing the layers towards each other, and the layers of one stream are directed at the same angles to the vertical and the layers of the second stream is directed at varying angles. 2. A device for desublimation of solids, comprising a desublimator with holes for supplying steam of a desublimated product and cold carrier gas and nodes for separating the finished product, characterized in that the device further comprises another desublimator and a mixing chamber, in the lower part of which there are slotted openings with guides, and on one wall of the chamber they are located at equal angles to the axis of the apparatus in the range of 30-75 °, and on the opposite wall - at different angles, increasing from 30 to 75 °, while both desublimators are equipped with steam and gas distribution chambers with gratings and sublimators.

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