RU2188067C2 - Box type pulsating reactor - Google Patents

Abstract

FIELD: chemical technology apparatus; chemical deposition of substances from solutions. SUBSTANCE: proposed reactor has housing with branch pipes for delivery of reagents and discharge of final products; housing is divided by partitions to ensure upper overflow of solutions to sections; they are provided with pulsating mixing units fitted with nozzles. Each section is provided with additional vertical partition which is so positioned that nozzles of pulsating mixing unit are located on both sides and reagent supply branch pipe is mounted in way of motion of flow behind additional partition. Reactor may be provided with settling chamber. Additional vertical partition may be detachable. EFFECT: facilitated procedure of obtaining sediments at preset properties; reduced outlays and power requirements. 3 cl, 2 dwg, 1 tbl

Description

 The invention relates to apparatuses of chemical, hydrometallurgical technology, namely to box-type reactors with pulsating mixing, and is intended for continuous chemical deposition of substances from solutions.

 Upon receipt of substances by chemical deposition, the following requirements are imposed on their sediments: first of all, according to the density of particles, their size and structure. Precipitation after deposition should be easily filtered, washed from impurities, calcined, have low dusting when working with them.

Known reactor for continuous chemical deposition of substances, containing a tubular body with nozzles for supplying solutions and issuing the resulting products. In the reactor, a supply pipe for the initial solution is located above the precipitation supply pipe (ed. St. 1494915 B 01 D 9/02, 1989)
When the initial solution and precipitation solution are fed into the reactor, they mix due to diffusion, while the precipitate formed, as the heaviest, falls into the bottom of the reactor, from where it is discharged from the reactor periodically, and the mother liquor is continuously above.

 The disadvantages of this reactor include the absence of a stirrer in it, which leads to the deposition and removal of both large and small particles of sediment from it, the deposition of substances without stirring does not create physical and chemical conditions for the gradual formation of crystallization centers and their growth, conditions are created in the deposition zone supersaturation of one chemical compound in another, which leads to mass formation of centers and the absence of conditions for their growth.

 Precipitation after deposition is colloidal, they are poorly filtered and separated, which increases the filtration time, reduces the productivity of equipment, increases material and energy costs.

 A box-type pulsation reactor is known that contains nozzles for supplying reagents and dispensing the products obtained, divided by partitions to provide an overflow of solution into sections with pulsating mixing devices with nozzles installed in them (in the book edited by S. Karpacheva, M. Fundamentals of the theory and calculation of horizontal pulsation apparatuses and pulsators.M.: Atomizdat, 1961, p. 13. Fig. 2 (c)).

 This reactor is structurally the closest to the claimed invention and is adopted as a prototype.

 This reactor can provide two-stage chemical deposition of substances, however, two-stage deposition also does not provide the formation of crystallization centers and does not exclude mass deposition, which leads to colloid-like precipitation, to reduce the productivity of equipment in subsequent processes, to increase material and energy costs.

 The technical problem solved by the present invention is to obtain precipitation with desired properties, reducing material and energy costs in subsequent processes of working with precipitation of the obtained substances.

 The solution to this problem is achieved by the fact that in a pulsed box reactor containing a housing with nozzles for supplying reagents and dispensing the resulting products, it is divided by partitions to provide an overflow of solutions into sections with pulsating mixing devices with nozzles installed in them, each mixing section is equipped with an additional partition, placed with ensuring the location of the nozzles of the pulsating mixing device on both sides of it, and the reagent supply pipe, are installed m in the direction of flow beyond the additional partition. In this case, one of the sections performs the purpose of the precipitation chamber, an additional vertical partition is removable.

 The reactor is shown in the drawings, where in Fig. 1 is a sectional perspective view, in Fig. 2 is a section along AA in Fig. 1.

 The box-type pulsation reactor comprises a housing 1, nozzles for supplying the initial solution 2, for discharging the reaction products 3, for precipitating 4, and blowing off 5. The housing is divided by partitions 6 and 7 into mixing sections 8 and 9 and sludge 10, providing an overflow of the solution. Each section of the deposition (mixing) contains a mixing device 11 with nozzles 12 and an additional vertical partition 13 with the placement of nozzles on both sides. The nozzle 14 of the input precipitator is installed under the level of the mixture and in the direction of flow beyond the additional partition.

 The pulsating mixing devices have nozzles 15 for supplying pressure pulses. An additional partition is removable with a guide device 16 and is installed relative to the bottom of the housing with a gap. To release the deposition sections from solutions in their lower part made pipes 17.

 The operation of the reactor is as follows. The initial solution is continuously fed into the deposition section 8 through the pipe 2 to the additional partition 13, and the precipitant is continuously introduced into each section under the mixture level through the pipe 14 after the additional partition. Pressure pulses are continuously fed into the mixing device 11 through the nozzles 15 with a frequency of 40-80 count / min, and the purge from the reactor is carried out through the nozzle 5. During the operation of the mixing device, solutions having different concentrations are averaged over it in the flow.

 The first portions of the averaged solution have no seed centers. As a precipitate forms, its dissolution decreases and then single crystallization centers are formed, the number of which then rapidly increases, which contributes to the crystallization process and crystal growth under conditions of increasing precipitant concentration. The process of formation of seed centers increases gradually along the flow from section to section, while the redistribution of the concentrations of precipitant and sediment in the mixture gradually occurs, which eliminates mass deposition, supersaturation of solutions in each other, the formation of seed centers and sediment in a short period of time.

 The concentration adjustment process is carried out from the beginning to the end of the deposition process in both sections of the reactor, then the mixture of solution through the baffle 7 is poured into section 10, where the sediment falls under its own weight and the mother liquor is discharged from the reactor by gravity through the pipe 3. Sediment from the bottom through the pipe 4 is issued periodically.

 The above scheme of chemical deposition of substances from solutions in the claimed reactor allows, when selecting the section volumes and their shape (height, cross section, volume of the mixing device), to configure it to precipitate any substances without the use of additional devices, substances to create seed or crystallization substances.

 The reactor was tested under production conditions at a technological installation during the deposition of ammonia salts of uranium. The results, taken as a unit, are given in the table in comparison with the results of the deposition of the same salts in a two-stage process in a two-section reactor under similar parameters and conditions.

 As can be seen from the table, the claimed reactor provides for the production of chemical precipitation of substances from solutions of precipitation with desired properties, which significantly increases the productivity of equipment in subsequent technological operations, reduces material and energy production costs.

Claims (3)

 1. A pulsating box-type reactor for carrying out chemical deposition processes, comprising a housing with nozzles for supplying reagents and dispensing the obtained products, separated by partitions to provide an overflow of solutions into sections with pulsating mixing devices with nozzles installed in them, characterized in that each mixing section is equipped additional vertical partition placed to ensure the location of the nozzles of the pulsating mixing device on both sides, and the pipe m for input of reagent set in the direction of flow of the additional partition.  2. The pulsation reactor according to claim 1, characterized in that it contains a settling chamber.  3. The pulsation reactor according to claim 1, characterized in that the additional vertical partition is removable.

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