RU2200057C1 - Reactor for direct synthesis of organochlorosilanes in fluidized bed - Google Patents

Abstract

FIELD: heat- and mass-exchange reactors for conducting processes in fluidized bed; silicoorganic industry for production of organochlorosilanes by direct synthesis from silicon-containing contact mass under action of alkyl chloride in fluidized bed. SUBSTANCE: proposed reactor includes housing, heat exchanger, contact mass loading and unloading units, gaseous component supply unit and finished product discharge unit, as well as gas distributors which are mounted coaxially inside housing. Each distributor is made in form of unit from vertical blades interconnected by means of inner fins dividing the reactor cavity into isolated sectors; units are turned relative to each other by half angle formed by adjacent blades. Distance between units shall not exceed height required for forming gas bubbles exceeding average width of reactor segments. EFFECT: enhanced conversion of gaseous component of reaction; reduction of entrapping of contact mass; reduced dynamic loads. 2 dwg

Description

 The present invention relates to heat transfer reactors for carrying out processes in a fluidized bed and can be used in the organosilicon industry for the production of organochlorosilanes by direct synthesis from a silicon-containing contact mass under the influence of alkyl chloride in a fluidized bed, as well as in other industries for carrying out processes using a fluidized bed.

 Alkylchlorosilanes are prepared by reacting a finely divided contact mass consisting of silicon and copper-based catalysts with a gaseous component - chloralkyl in a fluidized bed.

 Developments in the hardware design of this process, as a rule, were aimed at equalizing the gas-dynamic and thermal conditions throughout the reactor volume to optimize its use.

 A known reactor for the direct synthesis of organochlorosilanes in a fluidized bed, including a housing, a tubular heat exchanger, means for loading and unloading the contact mass, supplying a gaseous component and removing the finished product, as well as a gas distributor made in the form of a package of distribution elements installed along the apparatus axis, each of which represents two cylinders of larger and smaller diameters, interconnected by a ring, while at the free ends of the cylinders of larger and smaller diameters from the ends are made slots (US Pat. RF 2162735, 01 J 8/18, C 01 B 33/02, 2001).

 The disadvantage of the reactor is that when carrying out processes in the fluidized bed it is not possible to ensure uniform fluidization over the entire height of the dispersed layer. Even with perfect gas distribution, the gas phase tends to the axis of the apparatus, forming large bubbles, the diameter of which can reach 0.6-0.8 m ("Calculations of fluidized bed apparatus." Ed. IP Mukhlenova, BS Sazhin, V F. Frolova. L. "Chemistry", 1986, p.64). This reduces the conversion of the gas reagent in the reactors, increases the entrainment of the dispersed material, and also creates an alternating dynamic load on the structural elements installed inside the reactor, which leads to their failure.

 Closest to the proposed invention in technical essence, the achieved result and adopted by us as a prototype is a reactor for the direct synthesis of organochlorosilanes in a fluidized bed (US Pat. RF 1774550, 01 J 8/18, 1997). The known reactor contains a cylindrical body equipped with an external heat exchanger, means for loading and unloading the contact mass, supplying a gaseous component and removing the finished product, a gas distribution grid and an auxiliary gas distribution unit installed in the neck of the heat exchanger in the middle part of the reactor. The auxiliary gas distributor is made in the form of a hemispherical glass.

 The disadvantage of the prototype reactor is that the auxiliary gas distributor is located in it in the middle part in height in the transverse direction with respect to the gas stream.

 With a sufficient height of the reactor, large bubbles of the gaseous component are formed in its lower part, and the purpose of the auxiliary gas distributor is to destroy these bubbles, while the gas distributor experiences high alternating dynamic loads, which reduces the durability of its operation, as well as the durability of the internal parts of the reactor. In addition, the formation of large bubbles of a gaseous component is also possible in the upper part of the reactor.

 These disadvantages lead to a decrease in the conversion of the gaseous component of the reaction, an increase in the entrainment of fine particles of the contact mass.

 The objective of the invention is to increase the conversion of the gaseous component of the reaction, reduce the entrainment of the contact mass, reduce dynamic loads in the reactor.

 This problem is solved by the proposed reactor for the direct synthesis of organochlorosilanes in a fluidized bed, comprising a housing, a heat exchanger, means for loading and unloading the contact mass, supplying a gaseous component and exhausting the finished product, as well as gas distributors, in which, according to the invention, it is aligned with the height of the inside of the housing gas distributors are installed, each of which is made in the form of a block of vertical blades interconnected by internal ribs and dividing the reactor cavity into insulated dr g from another sector successively installed units are rotated relative to one another by half the angle formed by the adjacent blades. In this case, the distance between the blocks should be no more than the height necessary for the formation of gas bubbles that exceed the average width of the reactor segments.

 Figure 1 presents a General view of the reactor.

 Figure 2 presents a General view of the auxiliary gas distributors.

 The reactor includes a housing 1, inside of which a heat exchanger 2 is placed. The reactor is equipped with means (fittings) 3, 4 for loading the reaction mass and unloading the spent contact mass. At the bottom of the reactor there is a gas chamber and a gas distribution grid 5. The reactor has means (fittings) 6, 7 for introducing a gaseous component and outputting reaction products.

 Auxiliary gas distributors 8 are installed inside the reactor in the form of blocks of vertical blades 9, interconnected by internal ribs.

 The reactor operates as follows. Chloralkyl vapor, which, passing through the holes of the gas distributor, is introduced into the contact mass layer, creating a fluidized bed, is fed into the pre-loaded contact mass and heated reactor for the direct synthesis of organochlorosilanes through a gas distributor 6. Then the gaseous component bubbles formed along the height of the reactor meet on their way auxiliary gas distributors 8 installed in the reactor, and the bubbles are crushed and the gas flow is equalized. The resulting pairs of organochlorosilanes through the nozzle 7 are removed from the reactor.

 Compared with the prototype of the proposed reactor has the following advantages. The presence of auxiliary gas distributors in the reactor ensures a uniform distribution of the gaseous component of the reaction over its entire volume, which leads to an increase in the conversion of chloralkyl, a decrease in the entrainment of the contact mass, and a decrease in dynamic loads in the reactor.

Claims (1)

 A reactor for the direct synthesis of organochlorosilanes in a fluidized bed, including a housing, a heat exchanger, means for loading and unloading the contact mass, supplying a gaseous component and removing the finished product, as well as gas distributors, characterized in that auxiliary gas distributors are installed coaxially to the height of each other, each of which which is made in the form of a block of vertical blades interconnected by internal ribs and dividing the reactor cavity into sectors isolated from each other, and the last carefully installed blocks are rotated relative to each other by half the value of the angle formed by adjacent blades.

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