Sodium carbonate crystallization and separation device

Abstract

The utility model discloses a sodium carbonate crystallization separation device which is characterized in that an outlet of a feeding pump is connected with a tube pass inlet of a first-effect evaporator through a preheating unit, and a tube pass outlet of the first-effect evaporator is connected with a circulating inlet of a first-effect crystallizer; a salt leg outlet of the first-effect crystallizer is connected with a second-effect circulating pipe, and the second-effect circulating pipe is connected with a circulating liquid outlet of the second-effect crystallizer; a salt leg outlet of the second-effect crystallizer is connected with a settling section inlet of the third-effect crystallizer through a second-effect transfer pump; a salt leg outlet of the triple-effect evaporator is connected with a triple-effect thickening tank through a triple-effect discharging pump, a bottom outlet of the triple-effect thickening tank is connected with a triple-effect centrifugal machine, and a solid phase outlet of the triple-effect centrifugal machine is connected with a feeding port of a sodium carbonate belt filter through a sodium carbonate slurrying tank and a sodium carbonate slurrying pump; a solid discharge hole of the sodium carbonate belt filter is connected with a second-stage centrifugal machine through a second-stage centrifugal tank and a second-stage centrifugal pump; and a solid-phase outlet of the second-stage centrifugal machine is connected with a sodium carbonate monohydrate articulated chute. The sodium carbonate product obtained by the device is high in purity and low in energy consumption.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of evaporation crystallization separation devices, especially a kind of sodium carbonate crystallization separation device, belong to evaporation crystallization technical field. BACKGROUND

[0002] Sodium carbonate is a commonly used chemical raw material, widely used in all aspects of life, at present in the production process of many chemical by-products, sodium carbonate is generally removed as impurities, or converted into other inorganic salts to remove, and the hindering effect of sodium carbonate on the evaporation crystallization process of chemical by-products is very obvious, affects the continuous operation of system, affects the purity of product, the processing cost of waste salt produced in production is high, and economic benefit is poor.

[0003] The Chinese patent with publication number CN 118005121A discloses a sodium carbonate sodium bromide salt separation system and salt separation method, including a primary evaporation system, a secondary evaporation system and a tertiary evaporation system. This technical solution adopts a three-stage evaporation crystallization method, separating sodium carbonate by primary evaporation and secondary evaporation, and crystallizing sodium bromide by tertiary evaporation. The system has high energy consumption, low energy utilization rate, fine crystalline particles, large mother liquor circulation amount, and low sodium carbonate purity.

[0004] The Chinese patent with publication number CN 112811444B discloses a PTA incineration boiler ash solution salt separation and crystallization process, including sodium carbonate evaporation crystallization and sodium bromide evaporation crystallization, and using a displacement method in between. In this technical solution, a large amount of live steam is used for heating, the system has high energy consumption, low energy utilization rate, fine sodium carbonate crystalline particles, low sodium carbonate purity, high evaporation temperature, strong equipment corrosion, and large investment. SUMMARY

[0005] This section aims to outline some aspects of the embodiments of the present utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract of the specification and the utility model name, and such simplifications or omissions cannot be used to limit the scope of the present utility model.

[0006] In view of the above and / or problems existing in the prior art, the present utility model is proposed.

[0007] The purpose of the present utility model is to overcome the problems existing in the prior art, provide a sodium carbonate crystallization separation device, which improves the heat utilization efficiency in the evaporation process, effectively purifies the purity of sodium carbonate product, reduces energy consumption, separates sodium carbonate product, obtains high-concentration sodium bromide mother liquor containing a small amount of sodium carbonate, and realizes the growth of economic benefit.

[0008] To solve the above technical problems, the utility model discloses a sodium carbonate crystallization separation device, including feed tank, the outlet of feed tank is connected with the pipe course entrance of one effect evaporator through feed pump and preheating unit, the pipe course outlet of one effect evaporator is connected with the circulating liquid entrance of one effect crystallizer, the circulating liquid outlet of one effect crystallizer is connected with the pipe course entrance of one effect evaporator through one effect circulating pipe and the entrance of one effect circulating pump,

[0009] The salt leg outlet of one effect crystallizer is connected with the middle part of two effect circulating pipe, and the upper end of two effect circulating pipe is connected with the circulating liquid outlet of two effect crystallizer, and the lower end of two effect circulating pipe is connected with the circulating liquid entrance of two effect crystallizer through two effect circulating pump and the pipe course of two effect evaporator in proper order.

[0010] The salt leg outlet of two effect crystallizer is connected with the lower part settlement section entrance of three effect crystallizer through two effect material transfer pump, and the circulating liquid outlet of three effect crystallizer is connected with the circulating liquid entrance of three effect crystallizer through three effect circulating pipe, three effect circulating pump and the pipe course of three effect evaporator in proper order.

[0011] The salt leg outlet of three effect evaporator is connected with three effect thick tank through three effect material outlet pump, and the bottom outlet of three effect thick tank is connected with the entrance of three effect centrifugal machine, and the solid phase outlet of three effect centrifugal machine is connected with the feed inlet of sodium carbonate slurrying tank, and the bottom outlet of sodium carbonate slurrying tank is connected with the feed inlet of sodium carbonate belt filter through sodium carbonate slurrying pump, and the solid material outlet of sodium carbonate belt filter is connected with the feed inlet of secondary centrifugal tank, and the outlet of secondary centrifugal tank is connected with the entrance of secondary centrifugal machine through secondary centrifugal pump, and the solid phase outlet of secondary centrifugal machine is connected with sodium carbonate monohydrate chute.

[0012] As the improvement of the utility model, the outlet of feed pump is connected with the cold side entrance of primary preheater, the cold side outlet of primary preheater is connected with the cold side entrance of secondary preheater, the cold side outlet of secondary preheater is connected with the cold side entrance of tertiary preheater, the cold side outlet of tertiary preheater is connected with the cold side entrance of quaternary preheater, and the cold side outlet of quaternary preheater is connected with the pipe course entrance of one effect evaporator.

[0013] As the further improvement of the utility model, live steam pipe is connected with the shell course entrance of one effect evaporator, the shell course condensate outlet of one effect evaporator is connected with the entrance of one effect condensate tank, the outlet of one effect condensate tank is connected with the hot side entrance of quaternary preheater through one effect condensate pump, and the hot side outlet of quaternary preheater is connected with live steam condensate pipe.

[0014] As a further improvement of the present application, the secondary steam outlet of the one-effect crystallizer is connected with the shell side inlet of the evaporator, the secondary steam outlet of the two-effect crystallizer is connected with the shell side inlet of the three-effect evaporator and the three-stage preheater, and the shell side condensate outlets of the two-effect evaporator, the three-effect evaporator and the three-stage preheater are respectively connected with the inlets of the three-effect condensate tanks; the outlet of the three-effect condensate tank is connected with the hot side inlet of the two-stage preheater through a three-effect condensate pump, and the hot side outlet of the two-stage preheater is connected with a condenser condensate tank.

[0015] As a further improvement of the present application, the secondary steam outlet of the three-effect crystallizer is connected with the shell side inlet of the one-stage preheater and the three-effect condenser, the shell side outlet of the three-effect condenser is connected with the suction port of a three-effect vacuum pump, the shell side condensate outlets of the one-stage preheater and the three-effect condenser are connected with the condenser condensate tank, and the bottom outlet of the condenser condensate tank is connected with a condenser condensate pump and an evaporation condensate pipe to the condensate recycling system.

[0016] As a further improvement of the present application, the sodium carbonate belt filter is provided with multi-stage filtration, the current-stage filtration liquid outlet is connected with the inlet of a current-stage elution liquid tank, the discharge outlet of the current-stage elution liquid tank is connected with the inlet of a current-stage elution filter pump, the outlet of the first-stage elution filter pump is connected with the water inlet of a sodium carbonate slurry tank and the bottom elution port of a three-effect thick tank, and the outlet of the second-stage elution filter pump is connected with the inlet of a three-effect thick tank.

[0017] From the second-stage filtration liquid outlet, the current-stage elution filter pump is connected with the elution interface of the previous-stage filter, the outlet of the pure water pipe is connected with the pure water inlet of the second-stage centrifugal tank, the overflow port of the second-stage centrifugal tank is connected with the inlet of an overflow washing liquid tank, and the discharge outlet of the overflow washing liquid tank is connected with the final-stage filter elution interface of the sodium carbonate belt filter through an overflow washing liquid pump.

[0018] As a further improvement of the present application, the overflow port of the three-effect thick tank is connected with the inlet of a discharge buffer tank, the sidewall outlet of the discharge buffer tank is connected with the inlet of a filter through a sodium carbonate discharge pump, the filtered outlet of the filter is connected with a sodium bromide crystallization unit through a system discharge pipe, and the filter residue outlet of the filter is connected with the inlet of the sodium carbonate belt filter.

[0019] As a further improvement of the present application, the bottom outlet of the discharge buffer tank and the liquid phase outlet of the three-effect centrifugal machine are respectively connected with the inlets of a three-effect mother liquor tank, and the bottom outlet of the three-effect mother liquor tank is connected with the three-effect circulation pipe through a three-effect mother liquor pump.

[0020] With respect to the prior art, the utility model has obtained the following beneficial effects: 1, sodium carbonate evaporation crystallization feed adopts multistage preheating, gradient utilization heat of evaporation system, according to the temperature of feed and the temperature of each level including three effect evaporation secondary steam, evaporation condensate, two effect evaporation secondary steam, live steam condensate, gradient utilization heat of each level heat source, improve the temperature of feed, reduce three effect circulating cooling water total consumption, reduce system energy consumption.

[0021] 2, adopt the low temperature section evaporation crystallization of third effect, material concentrates in high temperature section, crystallize in low temperature section, through low temperature evaporation steam shunt preheating, reduce low temperature section flash intensity, improve crystalline particle size, sodium carbonate crystallization is sodium carbonate monohydrate, low temperature section crystallization discharge can maximize improve sodium carbonate crystallization rate, reduce the sodium bromide crystallization precipitation in the impurity of feed, simultaneously provide better feed conditions for subsequent sodium bromide cooling crystallization, reduce the energy consumption of subsequent process.

[0022] 3, the centrifugal separation process of sodium carbonate crystallization device's back section is provided with sodium carbonate discharge tank and filter two-stage separation purification process, effectively reduces the entrainment of sodium carbonate monohydrate solid particles in the discharge, ensures the stability of the feed of the subsequent process, and improves the recovery rate and yield of sodium carbonate.

[0023] 4, the crude sodium carbonate monohydrate crystal obtained by centrifugal separation is further purified through a filtering and washing process, a four-stage filtering and washing process is adopted, the characteristics of the belt filter are fully utilized, four filtering zones are arranged, and the upper-stage washing filtrate is used for washing step by step, so that the residual sodium bromide entrained in the sodium carbonate monohydrate centrifuged is effectively washed, the resolubility of the traditional multi-stage elution is reduced, the amount of sodium carbonate crystal dissolved is reduced, the yield of sodium carbonate monohydrate is ensured, and the product purity is improved.

[0024] 5, a washing device is arranged on the upper portion of the underflow discharge port of the sodium carbonate thick tank, the first-stage leaching filtrate of the belt filter is used for washing, the refluxing leaching filtrate enters the centrifuge along with the underflow to be centrifuged, the sodium bromide content in the feed solution of the centrifuge is effectively reduced, the sodium bromide entrained in the solid sodium carbonate monohydrate is reduced, the first-stage leaching filtrate with high sodium carbonate content can be returned to the three-effect evaporation system along with the centrifugal mother liquor to crystallize, the sodium carbonate solid content at the outlet of the three-effect evaporation system is improved, the first crystallization rate of sodium carbonate is improved, the remaining first-stage leaching filtrate enters the sodium carbonate slurry tank to stir the first-stage centrifugal sodium carbonate monohydrate into crystal slurry, the resolubility of the sodium carbonate monohydrate in the slurry section is reduced, the product yield is improved, the refluxing amount is reduced, and the energy consumption is reduced.

[0025] 6. After the sodium carbonate filtration and washing process, the solid sodium carbonate monohydrate enters the sodium carbonate secondary centrifuge tank for secondary slurrying. The secondary slurrying mainly relies on the separation mother liquor from the sodium carbonate secondary centrifuge. At the same time, a quantitative amount of clean water is added into the sodium bromide secondary centrifuge tank to maintain the stability of the ion content in the secondary slurry. Meanwhile, the overflow of the sodium bromide secondary centrifuge tank can enter the sodium carbonate washing water tank for the fourth-stage rinsing of sodium carbonate, effectively ensuring the quality of the sodium carbonate monohydrate entering the drying process. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The drawings are provided for reference and illustration only and are not intended to limit this utility model. Wherein:

[0027] Figure 1 This is a flowchart of the sodium carbonate crystallization separation device of this utility model;

[0028] In the diagram: V1. Feed tank; V2. First-effect condensate tank; V3. Third-effect condensate tank; V4. Condenser condensate tank; V5. First-effect crystallizer; V6. Second-effect crystallizer; V7. Third-effect crystallizer; V8. Third-effect thickener tank; V9. Discharge buffer tank; V10. Third-effect mother liquor tank; V11. Sodium carbonate slurry tank; V12. First-stage rinse liquid tank; V13. Second-stage rinse liquid tank; V14. Third-stage rinse liquid tank; V15. Fourth-stage rinse liquid tank; V16. Second-stage centrifuge tank; V17. Overflow rinse liquid tank;

[0029] E1. Primary preheater; E2. Secondary preheater; E3. Tertiary preheater; E4. Quaternary preheater; E5. Single-effect evaporator; E6. Double-effect evaporator; E7. Triple-effect evaporator; E8. Triple-effect condenser;

[0030] L1. Filter; L2. Triple-effect centrifuge; L3. Sodium carbonate belt filter; L4. Two-stage centrifuge;

[0031] B1. Feed pump; B2. Single-effect condensate pump; B3. Triple-effect condensate pump; B4. Condenser condensate pump; B5. Single-effect circulating pump; B6. Double-effect circulating pump; B7. Triple-effect circulating pump; B8. Triple-effect discharge pump; B9. Sodium carbonate discharge pump; B10. Triple-effect mother liquor pump; B11. Sodium carbonate slurry pump; B12. First-stage rinsing filtrate pump; B13. Second-stage rinsing filtrate pump; B14. Third-stage rinsing filtrate pump; B15. Fourth-stage rinsing filtrate pump; B16. Second-stage centrifugal pump; B17. Overflow rinsing liquid pump; B18. Double-effect transfer pump; B19. Triple-effect vacuum pump; B20. Belt filter vacuum pump;

[0032] G1. Sodium carbonate feed pipe; G2. Live steam condensate pipe; G3. Three-effect condensate pipe; G4. First-stage preheating condensate pipe; G5. Evaporation condensate pipe; G6. Live steam pipe; G7. One-effect discharge pipe; G8. Two-effect non-condensable gas pipe; G9. System discharge pipe; G10. One-water sodium carbonate pipe; G11. Pure water pipe; G12. Three-effect non-condensable gas pipe. DETAILED DESCRIPTION

[0033] In the following description of the present application, the terms "upper", "lower", "front", "back", "left", "right", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not mean that the device must have a specific orientation.

[0034] In order to make the technical means, creative features, purposes and effects realized by the present application easy to understand, the present application will be further described below in combination with specific drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0036] As shown in Figure 1 The sodium carbonate crystallization separation device of the present application includes a feed tank V1, a first-stage preheater E1, a second-stage preheater E2, a third-stage preheater E3, a fourth-stage preheater E4, a one-effect evaporator E5, a one-effect crystallizer V5, a two-effect evaporator E6, a two-effect crystallizer V6, a three-effect evaporator E7, a three-effect crystallizer V7, and a sodium carbonate belt filter L3.

[0037] The outlet of the sodium carbonate feed pipe G1 is connected to the feed tank V1, the outlet of the feed tank V1 is connected to the inlet of the feed pump B1, the outlet of the feed pump B1 is connected to the cold side inlet of the first-stage preheater E1, the cold side outlet of the first-stage preheater E1 is connected to the cold side inlet of the second-stage preheater E2, the cold side outlet of the second-stage preheater E2 is connected to the cold side inlet of the third-stage preheater E3, the cold side outlet of the third-stage preheater E3 is connected to the cold side inlet of the fourth-stage preheater E4, the cold side outlet of the fourth-stage preheater E4 is connected to the outlet pipe of the one-effect circulating pump B5 and then connected to the pipe-side bottom inlet of the one-effect evaporator E5, the upper outlet of the pipe-side of the one-effect evaporator E5 is connected to the circulating liquid inlet of the one-effect crystallizer V5, and the circulating liquid outlet of the one-effect crystallizer V5 is connected to the inlet of the one-effect circulating pump B5 through the one-effect circulating pipe.

[0038] The tube side of the first preheater E1 and the third preheater E3 is the cold side, and the shell side is the hot side. The bottom salt leg outlet of the first crystallizer V5 is connected to the middle of the second circulating pipe through the first discharge pipe G7, the upper end of the second circulating pipe is connected to the circulating liquid outlet of the second crystallizer V6, the lower end of the second circulating pipe is connected to the inlet of the second circulating pump B6, the outlet of the second circulating pump B6 is connected to the bottom inlet of the tube side of the second evaporator E6, and the upper outlet of the tube side of the second evaporator E6 is connected to the circulating liquid inlet of the second crystallizer V6.

[0039] The bottom salt leg outlet of the second crystallizer V6 is connected to the inlet of the second transfer pump B18, the outlet of the second transfer pump B18 is connected to the inlet of the lower settling section of the third crystallizer V7, the circulating liquid outlet of the third crystallizer V7 is connected to the inlet of the third circulating pump B7 through the third circulating pipe, the outlet of the third circulating pump B7 is connected to the bottom inlet of the tube side of the third evaporator E7, and the upper outlet of the tube side of the third evaporator E7 is connected to the circulating liquid inlet of the third crystallizer V7.

[0040] The bottom salt leg outlet of the third evaporator E7 is connected to the inlet of the third discharge pump B8, and the outlet of the third discharge pump B8 is connected to the inlet of the third thick tank V8. The overflow port of the third thick tank V8 is connected to the inlet of the discharge buffer tank V9, the side wall outlet of the discharge buffer tank V9 is connected to the inlet of the sodium carbonate discharge pump B9, the outlet of the sodium carbonate discharge pump B9 is connected to the inlet of the filter L1, and the filtered outlet of the filter L1 is connected to the sodium bromide crystallization unit through the system discharge pipe G9. The filter residue outlet of the filter L1 is connected to the inlet of the sodium carbonate belt filter L3.

[0041] The bottom outlet of the third thick tank V8 is connected to the inlet of the third centrifuge L2, the bottom outlet of the discharge buffer tank V9 is connected to the inlet of the third mother liquor tank V10, the liquid phase outlet of the third centrifuge L2 is also connected to the inlet of the third mother liquor tank V10, the bottom outlet of the third mother liquor tank V10 is connected to the inlet of the third mother liquor pump B10, and the outlet of the third mother liquor pump B10 is connected to the third circulating pipe of the inlet of the third circulating pump B7.

[0042] The solid phase outlet of the third centrifuge L2 is connected to the inlet of the sodium carbonate slurry tank V11, the bottom outlet of the sodium carbonate slurry tank V11 is connected to the inlet of the sodium carbonate slurry pump B11, and the outlet of the sodium carbonate slurry pump B11 is connected to the inlet of the sodium carbonate belt filter L3.

[0043] The first filtered liquid outlet of the sodium carbonate belt filter L3 is connected to the inlet of the first elution liquid tank V12, the discharge port of the first elution liquid tank V12 is connected to the inlet of the first elution filter liquid pump B12, the outlet of the first elution filter liquid pump B12 is connected to the water inlet of the sodium carbonate slurry tank V11 and the bottom elution port of the third thick tank V8.

[0044] The secondary filtrate outlet of the sodium carbonate belt filter L3 is connected with the inlet of the secondary elution liquid tank V13, the outlet of the secondary elution liquid tank V13 is connected with the inlet of the secondary elution filter pump B13, and the outlet of the secondary elution filter pump B13 is connected with the first filter elution interface of the sodium carbonate belt filter L3.

[0045] The tertiary filtrate outlet of the sodium carbonate belt filter L3 is connected with the inlet of the tertiary elution liquid tank V14, the outlet of the tertiary elution liquid tank V14 is connected with the inlet of the tertiary elution filter pump B14, and the outlet of the tertiary elution filter pump B14 is connected with the secondary filter elution interface of the sodium carbonate belt filter L3.

[0046] The fourth filtrate outlet of the sodium carbonate belt filter L3 is connected with the inlet of the fourth elution liquid tank V15, the outlet of the fourth elution liquid tank V15 is connected with the inlet of the fourth elution filter pump B15, and the outlet of the fourth elution filter pump B15 is connected with the tertiary filter elution interface of the sodium carbonate belt filter L3.

[0047] The solid outlet of the sodium carbonate belt filter L3 is connected with the inlet of the secondary centrifugal tank V16, the outlet of the pure water pipe G11 is connected with the pure water inlet of the secondary centrifugal tank V16, the overflow port of the secondary centrifugal tank V16 is connected with the inlet of the overflow washing liquid tank V17, the outlet of the overflow washing liquid tank V17 is connected with the inlet of the overflow washing liquid pump B17, and the outlet of the overflow washing liquid pump B17 is connected with the fourth filter elution interface of the sodium carbonate belt filter L3.

[0048] The top exhaust ports of the first elution liquid tank V12, the secondary elution liquid tank V13, the tertiary elution liquid tank V14, and the fourth elution liquid tank V15 are all connected with the air exhaust port of the belt filter vacuum pump B20.

[0049] The outlet of the secondary centrifugal tank V16 is connected with the inlet of the secondary centrifugal pump B16, the outlet of the secondary centrifugal pump B16 is connected with the inlet of the secondary centrifugal machine L4, and the solid phase outlet of the secondary centrifugal machine L4 is connected with the sodium carbonate pipe G10.

[0050] The live steam pipe G6 is connected with the shell inlet of the first evaporator E5, the shell condensate outlet of the first evaporator E5 is connected with the inlet of the first condensate tank V2, the outlet of the first condensate tank V2 is connected with the inlet of the first condensate pump B2, the outlet of the first condensate pump B2 is connected with the hot side inlet of the fourth preheater E4, and the hot side outlet of the fourth preheater E4 is connected with the live steam condensate pipe G2.

[0051] The top secondary steam outlet of the first crystallizer V5 is connected with the shell inlet of the second evaporator E6, and the shell condensate outlet of the second evaporator E6 is connected with the inlet of the third condensate tank V3.

[0052] The top steam outlet of the two-effect crystallizer V6 is connected to the shell inlet of the three-effect evaporator E7, and the shell outlet of the three-effect evaporator E7 is also connected to the inlet of the three-effect condensate tank V3.

[0053] The top steam outlet of the two-effect crystallizer V6 is also connected to the hot side inlet of the three-stage preheater E3, and the hot side outlet of the three-stage preheater E3 is also connected to the inlet of the three-effect condensate tank V3. The outlet of the three-effect condensate tank V3 is connected to the inlet of the three-effect condensate pump B3, and the outlet of the three-effect condensate pump B3 is connected to the hot side inlet of the two-stage preheater E2. The hot side outlet of the two-stage preheater E2 is connected to the condenser condensate tank V4 through the three-effect condensate pipe G3.

[0054] The top steam outlet of the three-effect crystallizer V7 is connected to the shell inlet of the three-effect condenser E8, and the tube side of the three-effect condenser E8 is connected to the circulating cooling water pipe. The shell outlet of the three-effect condenser E8 is connected to the suction port of the three-effect vacuum pump B19. The shell condensate outlet of the three-effect condenser E8 is connected to the condenser condensate tank V4.

[0055] The top steam outlet of the three-effect crystallizer V7 is also connected to the hot side inlet of the one-stage preheater E1, and the hot side outlet of the one-stage preheater E1 is also connected to the condenser condensate tank V4 through the one-stage preheating condensate pipe G4. The bottom outlet of the condenser condensate tank V4 is connected to the inlet of the condenser condensate pump B4, and the outlet of the condenser condensate pump B4 is connected to the condensate recycling system through the evaporation condensate pipe G5.

[0056] The non-condensable gas outlet of the upper part of the two-effect evaporator E6 is connected to the shell inlet of the three-effect condenser E8 through the two-effect non-condensable gas pipe G8, and the non-condensable gas outlet of the upper part of the three-effect evaporator E7 is connected to the shell inlet of the three-effect condenser E8 through the three-effect non-condensable gas pipe G12.

[0057] The crude solution from the sodium carbonate feed pipe G1 enters the feed tank V1, the sodium bromide content of the crude solution is about 18-22%, and the sodium carbonate content is 5-6%, the feed tank V1 is sent to the cold side of the first preheater E1 by the feed pump B1 for preheating, the temperature is increased from 25°C to 40°C, the discharge enters the cold side of the second preheater E2 for preheating, the temperature is increased to 50°C, the discharge enters the cold side of the third preheater E3 for preheating, the temperature is increased to 65°C, the discharge enters the cold side of the fourth preheater E4 for preheating, the temperature is increased to 75-80°C, the discharge is mixed with the first effect circulating liquid sent by the first effect circulating pump B5 and enters the tube side of the first effect evaporator E5 for heat exchange, after being heated, the material enters the first effect crystallizer V5 for evaporation and crystallization, the discharge relies on the pressure difference to flow into the second effect circulating pipe by the first effect discharge pipe G7, and is sent to the tube side of the second effect evaporator E6 by the second effect circulating pump B6 for heat exchange, after being heated, the material enters the second effect crystallizer V6 for evaporation and crystallization, the second effect evaporation and crystallization discharge is transported to the lower settling section of the third effect crystallizer V7 by the second effect transfer pump B18, the solid crystalline material in it, i.e. sodium carbonate monohydrate, settles to the discharge port at the bottom, the saturated solution in the second effect crystallization discharge is sent to the tube side of the third effect evaporator E7 by the third effect circulating pump B7 for heat exchange, after being heated, the material enters the third effect crystallizer V7 for evaporation and crystallization, and the discharge of the third effect evaporation and crystallization V7 is sent to the third effect thick tank V8 by the third effect discharge pump B8 for settling separation.

[0058] The overflow clear liquid of the third effect thick tank V8 enters the discharge buffer tank V9, the discharge of the discharge buffer tank V9 is sent to the filter L1 by the sodium carbonate discharge pump B9 for filtering and removing impurities, the sodium bromide content of the discharge of the filter L1 is about 48-50%, and the sodium carbonate content is 1-1.5%, which is sent out by the system discharge pipe G9 and enters the later-stage sodium bromide crystallization process.

[0059] The underflow of the third effect thick tank V8 enters the third effect centrifuge L2 for solid-liquid separation, the centrifugal mother liquor of the third effect centrifuge L2 and the bottom discharge of the discharge buffer tank V9 are all stored in the third effect mother liquor tank V10 temporarily, and the discharge of the third effect mother liquor tank V10 is transported back to the third effect circulating pipe at the inlet of the third effect circulating pump B7 by the third effect mother liquor pump B10.

[0060] The solid discharge of the third effect centrifuge L2 and the first-stage leaching liquid sent from the first-stage leaching filtrate pump B12 are together sent to the sodium carbonate slurry tank V11 for slurry stirring and washing, the discharge of the sodium carbonate slurry tank V11 is sent to the feed port of the sodium carbonate belt filter L3 by the sodium carbonate slurry pump B11, and the filter residue of the filter L1 also enters the feed port of the sodium carbonate belt filter L3, the first-stage filtrate of the sodium carbonate belt filter L3 enters the first-stage leaching liquid tank V12, and the discharge of the first-stage leaching liquid tank V12 is transported to the sodium carbonate slurry tank V11 and the bottom elution port of the third effect thick tank V8 by the first-stage leaching filtrate pump B12, respectively.

[0061] The secondary filtrate from the sodium carbonate belt filter L3 enters the secondary eluent tank V13. The discharge from the secondary eluent tank V13 is pumped by the secondary eluent pump B13 to the primary filter eluent interface of the sodium carbonate belt filter L3. The tertiary filtrate from the sodium carbonate belt filter L3 enters the tertiary eluent tank V14. The discharge from the tertiary eluent tank V14 is pumped by the tertiary eluent pump B14 to the secondary filter eluent interface of the sodium carbonate belt filter L3. The quaternary filtrate from the sodium carbonate belt filter L3 enters the quaternary eluent tank V15. The discharge from the quaternary eluent tank V15 is pumped by the quaternary eluent pump B15 to the tertiary filter eluent interface of the sodium carbonate belt filter L3.

[0062] Sodium carbonate monohydrate enters the secondary centrifuge tank V16 from the solids outlet of the sodium carbonate belt filter L3. Pure water is replenished quantitatively via a pure water pipe G11 connected to the pure water inlet of the secondary centrifuge tank V16. The overflow from the secondary centrifuge tank V16 enters the overflow washing tank V17. The discharge from the overflow washing tank V17 is sent by the overflow washing pump B17 to the rinsing port of the fourth-stage filter of the sodium carbonate belt filter L3. The discharge from the secondary centrifuge tank V16 is sent by the secondary centrifuge pump B16 to the secondary centrifuge L4. The centrifugal mother liquor from the secondary centrifuge L4 enters the secondary centrifuge tank V16. The solids separated from the secondary centrifuge L4 are output via the sodium carbonate monohydrate chute G10. The obtained sodium carbonate monohydrate solid has a purity ≥99.2% and a sodium bromide content ≤0.3%.

[0063] The live steam from the live steam pipe G6, with a temperature of 140–150°C, enters the shell-side steam inlet of the first-effect evaporator E5. The secondary steam generated by the evaporation of the first-effect crystallizer V5, with a temperature of 97–100°C, enters the shell-side steam inlet of the second-effect evaporator E6. The secondary steam generated by the evaporation of the second-effect crystallizer V6, with a temperature of 75–78°C, enters the shell-side steam inlets of the third-effect evaporator E7 and the third-stage preheater E3, respectively. The secondary steam generated by the evaporation of the third-effect crystallizer V7, with a temperature of 45–48°C, enters the shell-side steam inlets of the third-effect condenser E8 and the first-stage preheater E1, respectively.

[0064] The non-condensable gases from the two-effect evaporator E6 and the three-effect evaporator E7 enter the shell side of the three-effect condenser E8 together. Circulating cooling water is introduced into the tube side of the three-effect condenser E8. The non-condensable gases cooled by the three-effect condenser E8 are extracted and discharged by the three-effect vacuum pump B19. The exhaust ports of the first-stage rinse tank V12, the second-stage rinse tank V13, the third-stage rinse tank V14, and the fourth-stage rinse tank V15 are connected to the inlet of the belt filter vacuum pump B20. The outlet of the belt filter vacuum pump B20 is open to the atmosphere.

[0065] The condensed water discharged from the shell side of the first evaporator E5 flows into the first condensed water tank V2, and the condensed water in the first condensed water tank V2 is sent to the hot side inlet of the fourth preheater E4 by the first condensed water pump B2, the condensed water at the hot side outlet of the fourth preheater E4 has a temperature of 75-80℃, and is sent out through the live steam condensed water pipe G2.

[0066] The condensed water discharged from the shell side of the second evaporator E6, the condensed water discharged from the shell side of the third evaporator E7, and the condensed water discharged from the shell side of the third preheater E3 flow into the third condensed water tank V3 respectively, the condensed water in the third condensed water tank V3 is sent to the hot side inlet of the second preheater E2 by the third condensed water pump B3, the condensed water discharged from the hot side of the second preheater E2 is sent into the condenser condensed water tank V4 through the third condensed water pipe G3, the condensed water discharged from the hot side of the first preheater E1 is sent into the condenser condensed water tank V4 through the first preheater condensed water pipe G4, the condensed water discharged from the shell side of the third condenser E8 flows into the condenser condensed water tank V4, and the condensed water in the condenser condensed water tank V4 has a temperature of 45-48℃, and is sent out through the condenser condensed water pump B4 and the evaporated condensed water pipe G5.

[0067] The above only describes the preferred embodiments of the present application, and shows and describes the basic principles, main features and advantages of the present application, and does not limit the patent protection range of the present application, and the skilled in the art should understand that the present application is not limited by the above embodiments. In addition to the above embodiments, the present application can have other implementation manners without departing from the spirit and scope of the present application. The present application can also have various changes and improvements, and any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope of the present application. The protection scope of the present application is defined by the appended claims and their equivalents. The technical features not described in the present application can be realized by or using the prior art, and will not be described here.

Claims

1. A sodium carbonate crystallization separation apparatus comprising a feed tank, characterized in that, The outlet of the feed tank is connected with the inlet of the tube side of the evaporator through a feed pump and a preheating unit, the outlet of the tube side of the evaporator is connected with the inlet of the circulating liquid of the crystallizer, the outlet of the circulating liquid of the crystallizer is connected with the inlet of the evaporator through a circulating pipe and the inlet of the circulating pump of the evaporator; The outlet of the salt leg of the crystallizer is connected with the middle of the circulating pipe, the upper end of the circulating pipe is connected with the outlet of the circulating liquid of the crystallizer, and the lower end of the circulating pipe is connected with the inlet of the circulating liquid of the crystallizer through the circulating pump and the tube side of the evaporator in sequence. The outlet of the salt leg of the crystallizer is connected with the middle of the circulating pipe, the upper end of the circulating pipe is connected with the outlet of the circulating liquid of the crystallizer, and the lower end of the circulating pipe is connected with the inlet of the circulating liquid of the crystallizer through the circulating pump and the tube side of the evaporator in sequence. The outlet of the salt leg of the crystallizer is connected with the middle of the circulating pipe, the upper end of the circulating pipe is connected with the outlet of the circulating liquid of the crystallizer, and the lower end of the circulating pipe is connected with the inlet of the circulating liquid of the crystallizer through the circulating pump and the tube side of the evaporator in sequence.

2. The sodium carbonate crystallization separation apparatus of claim 1, wherein: The outlet of the salt leg of the crystallizer is connected with the middle of the circulating pipe, the upper end of the circulating pipe is connected with the outlet of the circulating liquid of the crystallizer, and the lower end of the circulating pipe is connected with the inlet of the circulating liquid of the crystallizer through the circulating pump and the tube side of the evaporator in sequence.

3. The sodium carbonate crystallization separation apparatus of claim 2, wherein: The outlet of the salt leg of the crystallizer is connected with the middle of the circulating pipe, the upper end of the circulating pipe is connected with the outlet of the circulating liquid of the crystallizer, and the lower end of the circulating pipe is connected with the inlet of the circulating liquid of the crystallizer through the circulating pump and the tube side of the evaporator in sequence.

4. The sodium carbonate crystallization separation apparatus of claim 2, wherein: The outlet of the salt leg of the crystallizer is connected with the middle of the circulating pipe, the upper end of the circulating pipe is connected with the outlet of the circulating liquid of the crystallizer, and the lower end of the circulating pipe is connected with the inlet of the circulating liquid of the crystallizer through the circulating pump and the tube side of the evaporator in sequence.

5. The sodium carbonate crystallization separation apparatus of claim 4, wherein: The outlet of the salt leg of the crystallizer is connected with the middle of the circulating pipe, the upper end of the circulating pipe is connected with the outlet of the circulating liquid of the crystallizer, and the lower end of the circulating pipe is connected with the inlet of the circulating liquid of the crystallizer through the circulating pump and the tube side of the evaporator in sequence. The outlet of the salt leg of the crystallizer is connected with the middle of the circulating pipe, the upper end of the circulating pipe is connected with the outlet of the circulating liquid of the crystallizer, and the lower end of the circulating pipe is connected with the inlet of the circulating liquid of the crystallizer through the circulating pump and the tube side of the evaporator in sequence. The outlet of the salt leg of the crystallizer is connected with the middle of the circulating pipe, the upper end of the circulating pipe is connected with the outlet of the circulating liquid of the crystallizer, and the lower end of the circulating pipe is connected with the inlet of the circulating liquid of the crystallizer through the circulating pump and the tube side of the evaporator in sequence. The outlet of the salt leg of the crystallizer is connected with the middle of the circulating pipe, the upper end of the circulating pipe is connected with the outlet of the circulating liquid of the crystallizer, and the lower end of the circulating pipe is connected with the inlet of the circulating liquid of the crystallizer through the circulating pump and the tube side of the evaporator in sequence.

6. The sodium carbonate crystallization separation apparatus of claim 1, wherein: The sodium carbonate belt filter is provided with multi-stage filtration, the outlet of the present stage of filtrate is connected with the inlet of the present stage of elution liquid tank, the outlet of the present stage of elution liquid tank is connected with the inlet of the present stage of elution filter pump, the outlet of the first stage of elution filter pump is connected with the water inlet of the sodium carbonate slurry tank and the bottom elution port of the three-effect thick tank; From the outlet of the second stage of filtrate, the present stage of elution filter pump is connected with the elution interface of the previous stage of filter; the outlet of the pure water pipe is connected with the pure water inlet of the second stage of centrifugal tank, the overflow port of the second stage of centrifugal tank is connected with the inlet of the overflow washing liquid tank, the outlet of the overflow washing liquid tank is connected with the elution interface of the last stage of filter of the sodium carbonate belt filter through the overflow washing liquid pump.

7. The sodium carbonate crystallization separation apparatus of any one of claims 1 to 6, wherein: The overflow port of the three-effect thick tank is connected with the inlet of the discharge buffer tank, the side wall outlet of the discharge buffer tank is connected with the inlet of the filter through the sodium carbonate discharge pump, the filtered outlet of the filter is connected with the sodium bromide crystallization unit through the system discharge pipe; the filter residue outlet of the filter is connected with the inlet of the sodium carbonate belt filter.

8. The sodium carbonate crystallization separation apparatus of claim 7, wherein: The bottom outlet of the discharge buffer tank and the liquid phase outlet of the three-effect centrifugal machine are respectively connected with the inlet of the three-effect mother liquor tank, the bottom outlet of the three-effect mother liquor tank is connected with the three-effect circulation pipe through the three-effect mother liquor pump.

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