SU1379969A1 - Multistage vacuum-crystallization installation - Google Patents

Abstract

The acquisition relates to the chemical industry and reduces energy costs and increases reliability. The installation includes after-flow connected pipes, pipes 10 and 9, respectively, for the suspension and the mother liquor, crystallizers (K) A, B, B. Each K contains a central pipe 2, a settling chamber (OK) A and an outer shell.

Description

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Circulation of the mother liquor with the circulation pump 6, the connected suction line 7 with the OK 6, and the discharge one with the lower part K. The overflow pipes 10 for the suspension are equipped with jet pumps 11 connected with the discharge line of the circulation pump 6. Each It is equipped with a vessel 15 and a vertical stand 20 with an overflow fitting 21 connected to the OK A, one hundred to 20 capable of vertical movement and installation of the fitting 21 and

height lb (0.6-1.2) 0 from the upper end of the central tube 2, where B is the diameter of the central tube 2. The initial solution is fed to the worm fitting 28. The mother liquor is transferred to the stage by the upper stage by | In part 4 of the OK 4. through a hundred to 20 gravity tubes through the transfer pipes TM 9, and through the suspension, through vessels 15, transfer pipes 10 and jet pumps 11. The finished product is discharged through pipes 10 last K. . 1 j, n, f-ly, 5 ill.

The invention relates to multistage vacuum crystallization plants used to obtain various crystalline products from solutions in large-scale chemical, metallurgical industries, in fertilizer production from other fields.

The aim of the invention is to reduce energy consumption and increase operational reliability.

FIG. 1 shows a scheme of a multistage vacuum crystallization unit (solution pipes are indicated by solid lines, pipes for suspension and an air-steam mixture are dotted and 1 and 3 are lines; Y4, respectively); in fig. 2 - degree of crystallization; in fig. 3 shows the node I in FIG. one; in fig. 4 is a variant of the constructive execution of the node I on

FIG. one; in fig. 5 - node II in figure 1 I

The multistage vacuum crystallization unit (see Fig. 1) includes the stages L, B, C crystallization. The number of crystallization stages can be any, but not less than two, and is determined by technical and economic calculations or technological requirements. Each stage of crystallization is made in the form of a mold, having a housing 1, a central tube 2, an internal cylindrical conic partition 3, which forms a settling chamber A. in the mold housing.

the steps are equipped with a jet pump 5 built into the central tube 2, which creates an internal circulation of the suspension in the housing 1. Instead of the jet

A pump for this purpose can also be used with an axial pump. The crystallizers of each stage A, B ... B also have an external circuit for the circulation of the mother liquor containing

circulation pump b, which is connected by the suction line 7 to the settling chamber 4, and the discharge line 8 to the lower part of the body 1 of the crystallizers. Every step A,

 B, C crystallization is connected one. on to another separate transfer pipes 9 and 10 for separate supply of the clarified mother liquor and the suspension, respectively. Downstream

 suspension tubes 10 are provided with

jet pumps 11 (in Fig. 1, this section of the flow pipes is conventionally shown enlarged), connected by means of pipelines 12 with the discharge lines 8 of circulation pumps of 6 subsequent stages. So, . A transfer pipe 10, through which the suspension is fed from the crystallization stage 1 of the crystallization body A to the crystallization stage 1 B, co-holds the jet pump 11 connected via pipeline 12 to the crystallization stage B of the crystallization pump . AT

5 turn transfer pipe 10, in. which feeds the sunslene and the body of the 1st stage of crystallization and the case of the first stage of crystallization, contains a jet pump t1 connected by a pipe 12 with the hygienic line 8 of the circulation pump of the 6th stage of crystallization B, etc. The jet pump 11 has a conical nozzle 13, which is placed coaxially with the overflow pipe 10 and faces the smaller base C toward the side of the suspension movement (the direction of suspension movement is shown by the arrow), i.e. aside, the next crystallization stage. Refilling pipes 10 for suspension are connected to vessels 15, which, when repaired, pipelines 16 are connected to the lower part of the settling chambers A. Vessels 15 are equipped with overflow pipes 17, the upper edges of which are located 100-300 mm above the upper end 18 of the central pipe 2. Overflowing nozzles 17 are provided with locking and regulating devices 19. The suspension of production crystals is withdrawn from the last stage of crystallization B through pipe 10.

Each stage A, B ... In the crystallization it is equipped with a rotary cage 20, which is connected to the upper part of the settling chamber A (the zone of the clarified mother liquor). Stokes 20 contain lateral rotary nipples 21, which are located at a height of 8 from the upper ends of the central pipes 2. The height of the left side of the overflow pipe 2 determines the optimum working level in the crystallizer of each stage, which depends on the concentration of crystals in circulating suspension, as well as the physicochemical properties of the solution, and is chosen empirically during the commissioning process. The height of the side overflow fittings 21 is determined by the ratio i, h (0.6-1.2) 0, where D is the diameter of the central pipes 2. The vertical stand 20 and the side overflow fittings 21 are made with the possibility of perforation. verticals The vertical legs 20 and the side overflow fittings 21 contain anium connectors 22, in which interchangeable tubes 23 of the required length can be inserted. The lateral overflow fittings of 21 steps L, B, C crystallization are connected by flow pipes 9 for illuminating

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The uterine uterine plant with all the remaining lii and 7 circulating nlososoo 6 subsequent stages of crystallization. The lateral overflow fitting 21 at the end of the crystallization stage B is connected to pipe 9, along which; The clarified mother liquor is removed from the device.

Vertical posts 20 and vessels 15 of crystallizers of each stage A, B ... B are connected by pipelines 2 and 25 with separators 26. Pa of the upper part of separators 26 are clampers 27 for removing the secondary section. The crystallization step A has a suction pump 28 placed on the suction line 7 of the circulation pump 6 pcs. To supply the initial hot solution.

The multistage vacuum crystallization unit is prepared for launch and operates as follows.

in a way.

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All stages A, B ... B are filled with the initial hot solution or cooled suspension to the required level. Then, pumping pumps 6 are included to create circulation of the solution, as well as condensation-Sch1I systems (not shown) of the secondary steam and create a vacuum in the stages L, B, C crystallization. When the required vacuum in the separators 26, which is set to varying from stage A to stage B with the minimum value in stage A and maximum in the last stage B, is reached, the initial hot solution starts to be continuously fed through nozzle 28 with shut-off and control devices closed 19 on the vessels 15. The transfer of the solution from the stage to the stage is carried out from the upper part of the settling chambers 4, where the clarified mother solution is located, the chambers 20 and through the lateral fittings 21 by gravity flow through the pipes 9 in the suction lintsh 7 each-: next stage of crystallization. By mixing the verticals of the legs 20 and lateral nepej. In particular, fittings 21 (for example, by selecting the required length of interchangeable nozzles 23) select the optimum working level in each stage of the crystal. The overheated solution supplied by the pump 6 to the lower part of the housing 1 is mixed in the central pipes 2 with

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pacTDOpoM, circulating in each case). A mixture of aa overheating boils up 0 separators 26 at the outlet of the pipe 2, ceMOHcnapR- 5, with the formation of supersaturation. The secondary vapor produced by the self-evaporation of the solution is removed through fittings 27, and the supersaturated solution H9 occurs. The formation and growth of crystals occurs. This mode of operation of a multi-stage vacuum crystallizer is maintained until accumulation of each stage A | in the circulating suspension. B ... In a given, the concentration of crystals necessary to obtain a large-crystalline product and eliminate the formation of incrustations. After the required mass of crystals in vessels 15 has been accumulated in vessels 1, the valve 19 is opened shut-off, devices 19 and the отTIMAL flow of suspension from the crystallizer of stage A to the crystallizer is established

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Intensive circulation of the suspension, which excludes the possibility of incrustation on the inner surfaces of the mold casing 1, the central tubes 2, cylindrical conic partitions E and in the outer circuits of the mother liquor. During this period, the flow pipes, 9 for the clarified mother liquor are also self-contained, since they are connected to the suction lines 7 of the circulation pumps 6, operating under a deeper vacuum and, as it were, sucking the solution from the flow pipes, 9 connecting the adjacent stages. tubes 10 for slurry, they are continuously flushed with a Circulating solution coming from the injection lines B of the coolant pumps 6.

The use of multistage va 1 of the cum-installation system with

Using a multistage in 1 wum-crystallization installation with

the last stage of the Century. Flow suspended. 35 bicarbonate suspension allows

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from step A to step, the suspension of liquid-proof crystals and stage B are withdrawn through pipelines 16 through vessels 15 and re-flow pipes 10. Supply of each stage of crystallization Q with vertical sewers connected to settling chambers 4 and suction lines 7 of circulation pumps 6 subsequent stages of crystallization allows to ensure a constant flow of the clarified mother liquor and to maintain an optimal working level of the circulating suspension in the crystallizers of the stages A, B ... C. The overflow pipes 10 are continuously fed at high speed with a stream of clarified mother liquor, which is an additional stimulator of the suspension movement and constantly runs through the pipes 10, excluding their blockage with crystals.

In case of emergency supply of power through fitting 28, the supply of the initial superheated solution to the suction line 7 of the circulating pump 6 is interrupted, gradually the solution level in the molds of stages A, B ... C decreases to the mark determined by the position of the overflow pipes 17, in vessels 15, i.e. crystal) 1eators of steps A, B ... B remain a wave of suspension above the upper end 18 of the central 45

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reduce energy costs during operation of the device for. by eliminating pumps for transferring between the stages of the slurry and the clarified mother liquor, to simplify the procedure for binding and adjusting the crystallizer, to increase the reliability of operation of the apparatus,

Claims (2)

1. Multiple vacuum crystallization unit, including at least two successively connected transfer pipes for the suspension and the mother liquor of the crystallizers, each of which contains a central pipe, a settling tank, a chamber and an external circuit for circulating the mother solution with a circulation pump, connected to the suction line with a settling chamber, and the discharge. - with the lower part of the crystallizer, detachment with the tem, 4TOi g, the goal is to reduce energy costs and increased operational reliability, T1: each flow pipe of the suspension is equipped with a jet pump connected to the discharge line of the subsequent pump, followed by a crystallizer. with a settling chamber. vertical stand with gshrelyivn (m fitting, connected, the intensive circulation of the suspension, which excludes the possibility of incrustations on the inner surfaces of the mold bodies 1, the central tubes 2, the cylindrical cone partitions E, and in the outer circuits of the mother liquor. During this period, the overflow pipes, 9 for the clarified mother liquor, also self-contain, since they are connected to the suction lines 7 of the circulation pumps 6, operating under deeper vacuum and, as it were, sucking the solution from the overflow pipes, 9, which connect adjacent stages. As for the flow pipes 10 for the suspension, they are constantly flushed by a Circulating solution coming from the injection lines to the pumping circuits 6. The use of a multi-stage one-UMC-installation with the booster suspension allows five 0 Q five 0 five reduce energy costs during operation of the device for. by eliminating pumps for transferring between the stages of the suspension and the clarified mother liquor, simplify the procedure for binding and adjusting the crystallisation system, increase the reliability of operation of the apparatus, Invention Formula 1. Multiple vacuum crystallization unit, including at least two successively connected flow pipes for suspension and mother solution of crystallizers, each of which contains a central pipe, a settling tank, a cam and an external circuit for circulation of the mother solution with a circulation pump connected by a suction line with a settling chamber, and the discharge. - with the lower part of the crystallizer, detachment with the tem, 4TOi g, the goal is to reduce energy costs and increase operational reliability, T1: each recharge pipe of the suspension is equipped with a jet pump, connected to the discharge line of the circulation pump of the subsequent crystallizer, connected with a settling chamber; a vertical stand with drainage (with a fitting, connected with a reflux pipe from the mother liquor to the suction side of the circulating pump and the subsequent cristipplector. 2. Installation under item 1, о t and h а-ш ш I with the fact that the vertical RST with overflow fitting is made Fam.g with a volvo-spindle vertical plremenich, while the overflow nozzle of flax is harvested at a height of & h is from the upper end of the Pipes pipe, defined by the ratio & h (0.6-1.2) 0, where D is the diameter of the central pipe. 1 {$ 1) 8.4 to IS tt Fil9