Eight-effect two-section evaporator set for sodium aluminate solution
By using the split structure of the eight-effect two-stage evaporator group and the full countercurrent evaporation technology, the problems of high steam consumption and insufficient steam-liquid separation in the mother liquor concentration evaporator of alumina production have been solved, achieving the effects of low steam consumption, sufficient steam-liquid separation and reuse of secondary condensate.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-16
- Publication Date
- 2026-03-24
AI Technical Summary
Existing mother liquor concentration evaporators for alumina production suffer from high steam consumption, insufficient steam-liquid separation, and severe liquid entrainment, resulting in high production costs and the inability to reuse secondary condensate.
The system employs an eight-effect, two-stage evaporator assembly, including a heating chamber, a vapor-liquid separation chamber, and a self-evaporating flash evaporator. It utilizes a split structure and full countercurrent evaporation technology, achieving thorough vapor-liquid separation and multiple uses of secondary steam through a six-stage self-evaporating flash evaporator and a two-stage feeding method.
It reduces steam consumption, minimizes liquid entrainment and alkali runoff, achieves thorough vapor-liquid separation, allows secondary condensate to be reused, and lowers production costs.
Smart Images
Figure CN224024258U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to the concentration evaporation equipment technical field of alumina production circulating mother liquor, concretely relates to eight effect two -stage evaporator group of sodium aluminate solution. BACKGROUND
[0002] Bayer method is a kind of chemical process widely used in industry from bauxite production alumina, its basic principle is to use concentrated sodium hydroxide solution to convert aluminum hydroxide into sodium aluminate, by dilution and adding aluminum hydroxide seed to make aluminum hydroxide reprecipitate, the remaining sodium hydroxide solution is used to handle the next batch of bauxite, realizes continuous production;But for the concentration evaporation of alumina production mother liquor-sodium aluminate solution, generally adopt three effect, four effect, five effect natural circulation evaporator group, five effect, six effect falling film evaporator group;The defects of these evaporators when operating are as follows: one is high steam consumption (three effect evaporator group operation steam consumption reaches 0.5~0.6 t steam / t water, four effect evaporator group operation steam consumption reaches 0.4~0.5 t steam / t water, five effect evaporator group operation steam consumption reaches 0.35~0.4 t steam / t water, six effect evaporator group operation steam consumption reaches 0.3~0.35 t steam / t water), cause high production cost;Two is that the heating chamber and separation chamber of the falling film evaporator in use are integral structure, steam-liquid separation is not sufficient, causes liquid mist entrainment, serious running alkali, secondary condensate water cannot be returned to boiler and reused;Therefore, it is very necessary to provide an eight effect two-stage evaporator group of sodium aluminate solution with reasonable structure, low steam consumption, split structure, full steam-liquid separation and full counterflow evaporation technology. SUMMARY
[0003] The utility model discloses a kind of eight effect two-stage evaporator groups of sodium aluminate solution with reasonable structure, low steam consumption, split structure, full steam-liquid separation and full counterflow evaporation technology, to overcome the deficiencies of prior art.
[0004] The utility model discloses a kind of eight effect two-stage evaporator groups of sodium aluminate solution with reasonable structure, low steam consumption, split structure, full steam-liquid separation and full counterflow evaporation technology, to overcome the deficiencies of prior art.
[0005] The solution concentration loop is formed by the first concentration branch and the second concentration branch arranged side by side.
[0006] The steam circulation loop includes an external steam inlet pipeline for generating steam and condensing, a primary condensate tank and a primary condensate pump for recovering condensate water.
[0007] The first concentration branch is composed of I, II, III, IV, V, VI heating chambers, I, II, III, IV, V, VI flash evaporators connected in series; the lower inlet of the VI heating chamber is connected with the raw liquid feeding pipeline, and the bottom outlet of the VI flash evaporator is connected with the product recovery pipeline.
[0008] The second concentration branch is composed of VII and VIII heating chambers connected in series; the lower inlet of the VIII heating chamber is connected with the raw liquid feeding pipeline, and the bottom outlet of the VII heating chamber is connected with the product recovery pipeline.
[0009] The lower outlet and the top inlet of each heating chamber are provided with a circulating feeding pipeline, and a circulating pump is arranged on the circulating feeding pipeline; a feeding pump is arranged on the material conveying pipeline between the adjacent two heating chambers and between the II heating chamber and the II flash evaporator.
[0010] The external live steam feeding pipeline is connected with the steam inlet of the I heating chamber; the secondary steam outlets of the I to VIII heating chambers are connected with the corresponding vapor-liquid separation chambers, and the secondary steam outlets of the I to VIII vapor-liquid separation chambers are respectively connected with the steam inlets of the next heating chambers.
[0011] The secondary steam outlets of the I to VI flash evaporators are respectively connected with the II to VIII separation chambers; a water cooler and a vacuum pump are connected with the steam outlet pipeline of the VII vapor-liquid separation chamber.
[0012] The primary condensate water of the I heating chamber is collected through a primary condensate water tank and a primary condensate water pump; the secondary condensate water of the II, III, IV, V, VI, VII and VIII heating chambers is collected through a secondary condensate water tank and a secondary condensate water pump after being combined.
[0013] The first concentration branch circulating mother liquor directly enters the VI heating chamber, and then enters the V, IV, III, II and I heating chambers in sequence, and then enters the I flash evaporator; the second concentration branch circulating mother liquor directly enters the VIII heating chamber and then enters the VII heating chamber for countercurrent operation.
[0014] The first concentration branch enters the I flash evaporator, and then enters the II, III, IV, V and VI flash evaporators in sequence.
[0015] A discharge pump is arranged on the product recovery pipeline.
[0016] The utility model discloses a sodium aluminate solution eight-effect two-stage evaporator set, in use, the utility model discloses the advantage that eight effect operation can make seven times of secondary steam utilization, and the steam consumption is lower when the solution is concentrated, the two-stage (I-VI effect is one stage, VII-VIII effect is two stages) full counterflow (the running direction of raw material in one stage and two stages is opposite with the running direction of steam) type concentration evaporation technology makes the material that enters I effect heating chamber reduce, thereby reducing the consumption of live steam caused by material temperature rise, the heating chamber and separation chamber of the utility model adopt split type structure to carry out falling film evaporation, adopt novel demisting separator technology, make steam-liquid separation sufficient, do not exist liquid froth entrainment, run alkali situation, and secondary condensate can return to the boiler and be used repeatedly, the utility model has the advantages of reasonable structure, low steam consumption, split type structure, sufficient steam-liquid separation, full counterflow evaporation technology. BRIEF DESCRIPTION OF DRAWINGS
[0017] Fig. 1 It is the whole structure schematic diagram of the utility model.
[0018] Fig. 2 It is the material flow chart of the utility model.
[0019] Fig. 3 It is the steam flow chart of the utility model.
[0020] In the drawing: 1a, I effect heating chamber 1b, II effect heating chamber 1c, III effect heating chamber 1d, IV effect heating chamber 1e, V effect heating chamber 1f, VI effect heating chamber 1g, VII effect heating chamber 1h, VIII effect heating chamber 2a, I effect steam-liquid separation chamber 2b, II effect steam-liquid separation chamber 2c, III effect steam-liquid separation chamber 2d, IV effect steam-liquid separation chamber 2e, V effect steam-liquid separation chamber 2f, VI effect steam-liquid separation chamber 2g, VII effect steam-liquid separation chamber 2h, VIII effect steam-liquid separation chamber 3a, I grade flash evaporator 3b, II grade flash evaporator 3c, III grade flash evaporator 3d, IV grade flash evaporator 3e, V grade flash evaporator 3f, VI grade flash evaporator 4, raw liquid feeding pipeline 5, finished product recovery pipeline 6, circulating feeding pipeline 7, circulating pump 8, material pump 9, external live steam inlet pipeline 10, water cooler 11, vacuum pump 12, primary condensate tank and primary condensate pump 13, secondary condensate tank and secondary condensate pump 14, discharge pump. DETAILED DESCRIPTION
[0021] The utility model will be further explained in connection with the drawings. EMBODIMENT
[0022] As Figs. 1-3The eight-effect two-stage evaporator group of sodium aluminate solution is shown, which comprises an evaporator group composed of a heating chamber, a vapor-liquid separation chamber and a self-evaporation flash evaporator, the evaporator group adopts eight-effect heating chambers and separation chambers, six-stage self-evaporation flash evaporators and two-stage feeding and discharging modes; the eight-effect two-stage evaporator group with the heating chamber and the vapor-liquid separation chamber connected in sequence forms a solution concentration loop and a steam circulation loop.
[0023] The solution concentration loop is composed of the first concentration branch and the second concentration branch arranged in parallel.
[0024] The steam circulation loop comprises an external live steam inlet pipeline 9 for condensation of live steam and recovery of condensate water, a primary condensate tank and a primary condensate pump 12, and further comprises a secondary condensate tank and a secondary condensate pump 13 for condensation of secondary steam and recovery of condensate water.
[0025] The first concentration branch is composed of the I-effect heating chamber 1a, the II-effect heating chamber 1b, the III-effect heating chamber 1c, the IV-effect heating chamber 1d, the V-effect heating chamber 1e, the VI-effect heating chamber 1f, the I-stage flash evaporator 3a, the II-stage flash evaporator 3b, the III-stage flash evaporator 3c, the IV-stage flash evaporator 3d, the V-stage flash evaporator 3e and the VI-stage flash evaporator 3f connected in series; the lower feeding port of the VI-effect heating chamber 1f is connected with the raw solution feeding pipeline 4, and the bottom discharging port of the VI-stage flash evaporator 3f is connected with the product recovery pipeline 5.
[0026] The second concentration branch is composed of the VII-effect heating chamber 1g and the VIII-effect heating chamber 1h connected in series; the lower feeding port of the VIII-effect heating chamber 1h is connected with the raw solution feeding pipeline 4, and the bottom discharging port of the VII-effect heating chamber 1g is connected with the product recovery pipeline 5.
[0027] The circulating feeding pipeline 6 is arranged between the lower discharging port and the top feeding port of each heating chamber, and the circulating pump 7 is arranged on the circulating feeding pipeline 6; the material conveying pump 8 is arranged on the material conveying pipeline between the adjacent two heating chambers and between the II-effect heating chamber 1b and the II-stage flash evaporator 3b.
[0028] The discharging pump 14 is arranged on the product recovery pipeline 5.
[0029] The first concentration branch circulating mother liquor directly enters the VI-effect heating chamber 1f, then enters the V-effect heating chamber 1e, the IV-effect heating chamber 1d, the III-effect heating chamber 1c, the II-effect heating chamber 1b, the I-effect heating chamber 1a in sequence, and then enters the I-stage flash evaporator 3a; the second concentration branch circulating mother liquor directly enters the VIII-effect heating chamber 1h and then enters the VII-effect heating chamber 1g for countercurrent operation.
[0030] In the embodiment, the present application adopts countercurrent feeding operation, in the countercurrent feeding process, two sections of liquid feed are opposite to the direction of steam, the liquid feed is added from the last effect, concentrated by evaporation, the concentrated liquid is pumped into the previous effect until the last effect to obtain finished product complete liquid; the live steam is added from the first effect, condensed into liquid by releasing heat, the generated secondary steam enters the second effect, condensed into liquid after heating the liquid feed, the secondary steam generated by the second effect enters the third effect to heat the raw liquid, condensed into liquid after releasing heat, and so on until entering the eighth effect.
[0031] In the countercurrent feeding process, because the temperature increases with the increase of the concentration of the concentrated liquid, the viscosity of each effect is relatively small, and the heat transfer coefficient is basically the same; the finished product complete liquid is discharged at a relatively high temperature, and can be further concentrated by flash evaporation under reduced pressure.
[0032] The first concentration branch enters the first-stage flash evaporator 3a, and then enters the second-stage flash evaporator 3b, the third-stage flash evaporator 3c, the fourth-stage flash evaporator 3d, the fifth-stage flash evaporator 3e and the sixth-stage flash evaporator 3f in sequence.
[0033] The sodium aluminate solution eight-effect two-section evaporator set, in use, has the advantages that eight-effect operation can make seven times of secondary steam utilization, so that the steam consumption is lower when the solution is concentrated; the two-section (the first to sixth effects are a section, and the seventh to eighth effects are a second section) full countercurrent (the running directions of the raw materials in the first section and the second section are opposite to the running direction of the steam) concentration evaporation technology reduces the material in the first heating chamber, thereby reducing the consumption of live steam caused by the heating of the material; the heating chamber and the separation chamber of the present application adopt a split structure for falling film evaporation, adopt a new type of demister separator technology, so that the vapor-liquid separation is sufficient, there is no liquid mist entrainment and alkali running, and the secondary condensate water can be returned to the boiler for reuse; the present application has the advantages of reasonable structure, low steam consumption, split structure, sufficient vapor-liquid separation, full countercurrent evaporation technology. Embodiment
[0034] As shown in Figs. 1-3 The sodium aluminate solution eight-effect two-section evaporator set, it comprises an evaporator set composed of a heating chamber, a vapor-liquid separation chamber and a self-evaporation flash evaporator, the evaporator set adopts an eight-effect heating chamber and a separation chamber, adopts a six-stage self-evaporation flash evaporator, and adopts a two-section feeding and discharging mode; the eight-effect two-section evaporator set composed of the heating chamber and the vapor-liquid separation chamber connected in sequence constitutes a solution concentration loop and a steam circulation loop;
[0035] The solution concentration loop is composed of a first concentration branch and a second concentration branch arranged in parallel;
[0036] The steam circulation loop comprises an external live steam inlet pipeline 9 for condensation of live steam and recovery of its condensate, a primary condensate tank and a primary condensate pump 12; and further comprises a secondary condensate tank and a secondary condensate pump 13 for condensation of secondary steam and recovery of its condensate.
[0037] The external live steam inlet pipeline 9 is connected to the steam inlet of the I-effect heating chamber 1a; the secondary steam outlets of the I-VIII-effect heating chambers are connected to the corresponding vapor-liquid separation chambers, i.e. the secondary steam outlet of the I-effect heating chamber 1a is connected to the I-effect vapor-liquid separation chamber 2a, the secondary steam outlet of the II-effect heating chamber 1b is connected to the II-effect vapor-liquid separation chamber 2b, and so on, and the secondary steam outlet of the VIII-effect heating chamber 1h is connected to the corresponding VIII-effect vapor-liquid separation chamber 2h.
[0038] The secondary steam outlet pipelines of the I-VIII-effect vapor-liquid separation chambers are respectively connected to the steam inlets of the next-effect heating chambers, i.e. the secondary steam outlet pipeline of the I-effect vapor-liquid separation chamber 2a is connected to the steam inlet of the II-effect heating chamber 1b, the secondary steam outlet pipeline of the II-effect vapor-liquid separation chamber 2b is connected to the steam inlet of the III-effect heating chamber 1c, and so on, and the secondary steam outlet pipeline of the VII-effect vapor-liquid separation chamber 2g is connected to the steam inlet of the VIII-effect heating chamber 1h.
[0039] Meanwhile, the secondary steam outlet pipeline of the I-stage flash evaporator 3a is connected to the II-effect vapor-liquid separation chamber 2b, the secondary steam outlet pipeline of the II-stage flash evaporator 3b is connected to the III-effect vapor-liquid separation chamber 2c, the secondary steam outlet pipeline of the III-stage flash evaporator 3c is connected to the IV-effect vapor-liquid separation chamber 2d, the secondary steam outlet pipeline of the IV-stage flash evaporator 3d is connected to the V-effect vapor-liquid separation chamber 2e, the secondary steam outlet pipeline of the V-stage flash evaporator 3e is connected to the VI-effect vapor-liquid separation chamber 2f, and the secondary steam outlet pipeline of the VI-stage flash evaporator 3f is connected to the VII-effect vapor-liquid separation chamber 2g.
[0040] That is, the secondary steam outlet pipelines of the I-VI-stage flash evaporators are respectively connected to the II-VIII-effect separation chambers; and the steam outlet pipeline of the VII-effect vapor-liquid separation chamber 2h is connected with a water cooler 10 and a vacuum pump 11.
[0041] The primary condensate of the I-effect heating chamber 1a is collected by the primary condensate tank and the primary condensate pump 12; and the secondary condensate of the II-effect heating chamber 1b, the III-effect heating chamber 1c, the IV-effect heating chamber 1d, the V-effect heating chamber 1e, the VI-effect heating chamber 1f, the VII-effect heating chamber 1g and the VIII-effect heating chamber 1h is collected by the secondary condensate tank and the secondary condensate pump 13 after being combined.
[0042] In the present embodiment, specifically, during operation, the circulating mother liquor with a concentration of about 160 g / L enters the Ⅵ-effect heating chamber 1f and the Ⅷ-effect heating chamber 1h according to the flow of the two concentration branches through the raw solution feeding pipeline 4; the raw solution entering the Ⅷ-effect heating chamber 1h is heated and evaporated once in the Ⅷ-effect heating chamber 1h, then enters the Ⅶ-effect heating chamber 1g to be heated and evaporated again, and the concentrated product solution with a concentration of about 220 g / L is obtained;
[0043] The raw solution entering the Ⅵ-effect heating chamber 1f is sequentially heated and evaporated in the Ⅵ-effect heating chamber 1f, the Ⅴ-effect heating chamber 1e, the Ⅳ-effect heating chamber 1d, the Ⅲ-effect heating chamber 1c, the Ⅱ-effect heating chamber 1b and the Ⅰ-effect heating chamber 1a, and then is sequentially cooled and self-evaporated in the Ⅰ-stage flash evaporator 3a, the Ⅱ-stage flash evaporator 3b, the Ⅲ-stage flash evaporator 3c, the Ⅳ-stage flash evaporator 3d, the Ⅴ-stage flash evaporator 3e and the Ⅵ-stage flash evaporator 3f, and the product solution with a concentration of about 250 g / L is obtained;
[0044] Finally, the product solutions obtained by the first concentration branch and the second concentration branch are combined and collected by the discharge pump 14, as shown in Fig. 1 、 2 .
[0045] At the same time, the hot steam with a temperature of 158℃ introduced from the high-temperature steam source first enters the Ⅰ-effect heating chamber 1a to heat and concentrate the solution in the Ⅰ-effect heating chamber 1a, the secondary steam evaporated from the Ⅰ-effect heating chamber 1a enters the Ⅱ-effect heating chamber 1b through the Ⅰ-effect vapor-liquid separation chamber 2a, the secondary steam evaporated from the Ⅱ-effect heating chamber 1b enters the Ⅲ-effect heating chamber 1c through the Ⅱ-effect vapor-liquid separation chamber 2b, the secondary steam evaporated from the Ⅲ-effect heating chamber 1c enters the Ⅳ-effect heating chamber 1d through the Ⅲ-effect vapor-liquid separation chamber 2c, the secondary steam evaporated from the Ⅳ-effect heating chamber 1d enters the Ⅴ-effect heating chamber 1e through the Ⅳ-effect vapor-liquid separation chamber 2d, and so on, the secondary steam evaporated from the Ⅶ-effect heating chamber 1g enters the Ⅷ-effect heating chamber 1h through the Ⅶ-effect vapor-liquid separation chamber 2g, and the secondary steam evaporated from the Ⅷ-effect heating chamber 1h (the temperature can be reduced to 50℃) enters the water cooler 10 through the Ⅷ-effect vapor-liquid separation chamber 2h.
[0046] The secondary steam from the Ⅰ-stage flash evaporator 3a enters the Ⅱ-effect vapor-liquid separation chamber 2b, the secondary steam from the Ⅱ-stage flash evaporator 3b enters the Ⅲ-effect vapor-liquid separation chamber 2c, the secondary steam from the Ⅲ-stage flash evaporator 3c enters the Ⅳ-effect vapor-liquid separation chamber 2d, the secondary steam from the Ⅳ-stage flash evaporator 3d enters the Ⅴ-effect vapor-liquid separation chamber 2e, the secondary steam from the Ⅴ-stage flash evaporator 3e enters the Ⅵ-effect vapor-liquid separation chamber 2f, and the secondary steam from the Ⅵ-stage flash evaporator 3f enters the Ⅶ-effect vapor-liquid separation chamber 2g, as shown in Fig. 1 、 3 .
[0047] In summary, the eight-effect two-stage evaporator group for circulating mother liquor of alumina of the application has a steam consumption of 0.18 tons of steam per ton of water, compared with the six-effect single-stage evaporator group, 0.16 tons of steam can be saved for evaporating 1 ton of water; if the technology is popularized nationwide with the national alumina production capacity of 50 million tons, 25 million tons of steam can be saved annually, 5 million tons of power coal can be saved, and economic benefits of more than 3 billion yuan can be generated annually.
[0048] The eight-effect two-stage evaporator group for sodium aluminate solution has the advantages that the eight-effect operation can make the secondary steam be utilized for seven times, and the steam consumption is lower when the solution is concentrated; the two-stage (the first stage is the first to sixth effects, and the second stage is the seventh to eighth effects) full counter-flow (the running directions of the raw materials and the steam in the first stage and the second stage are opposite) concentration evaporation technology is adopted to reduce the material entering the first heating chamber, thereby reducing the consumption of the live steam caused by the material heating; the heating chamber and the separation chamber adopt the split structure for falling film evaporation, the new type of defoaming separator technology is adopted to fully separate the steam and the liquid, the liquid mist entrainment and the alkali running do not exist, the secondary condensate water can be returned to the boiler for repeated use; the eight-effect two-stage evaporator group has the advantages of reasonable structure, low steam consumption, split structure, full steam and liquid separation, and full counter-flow evaporation technology.
Claims
1. An eight-effect, two-stage evaporator assembly for sodium aluminate solution, comprising an evaporator assembly consisting of a heating chamber, a vapor-liquid separation chamber, and a self-evaporating flash evaporator, characterized in that: The evaporator group adopts an eight-effect heating chamber and a separation chamber, a six-stage self-evaporating flash evaporator, and a two-stage inlet and outlet method; the eight-effect two-stage evaporator group, in which the heating chamber and the vapor-liquid separation chamber are connected in sequence, constitutes a solution concentration loop and a steam circulation loop; The solution concentration circuit consists of a first concentration branch and a second concentration branch arranged in parallel. The steam circulation loop includes an external live steam inlet pipe for condensing live steam and recovering its condensate, a primary condensate tank, and a primary condensate pump; it also includes a secondary condensate tank and a secondary condensate pump for condensing secondary steam and recovering its condensate.
2. The sodium aluminate solution eight-effect two-stage evaporator assembly according to claim 1, characterized in that: The first concentration branch consists of a series of heating chambers connected in series: a first-effect heating chamber, a second-effect heating chamber, a third-effect heating chamber, a fourth-effect heating chamber, a fifth-effect heating chamber, a sixth-effect heating chamber, a first-stage flash evaporator, a second-effect flash evaporator, a third-effect flash evaporator, a fourth-effect flash evaporator, a fifth-effect flash evaporator, and a sixth-effect flash evaporator. The lower inlet of the sixth-effect heating chamber is connected to the raw liquid feed pipeline, and the bottom outlet of the sixth-effect flash evaporator is connected to the finished product recovery pipeline.
3. The sodium aluminate solution eight-effect two-stage evaporator group according to claim 2, characterized in that: The second concentration branch consists of a VII-effect heating chamber and a VIII-effect heating chamber connected in series; the lower inlet of the VIII-effect heating chamber is connected to the raw liquid inlet pipeline, and the bottom outlet of the VII-effect heating chamber is connected to the finished product recovery pipeline.
4. The sodium aluminate solution eight-effect two-stage evaporator assembly according to claim 3, characterized in that: A circulating feed pipe is provided between the lower discharge port and the top feed port of each heating chamber, and a circulating pump is provided on the circulating feed pipe; a feed pump is provided on the material conveying pipeline between two adjacent heating chambers and on the material conveying pipeline connecting the II-effect heating chamber and the II-stage flash evaporator.
5. The sodium aluminate solution eight-effect two-stage evaporator assembly according to claim 4, characterized in that: The external live steam inlet pipe is connected to the steam inlet of the first-effect heating chamber; the secondary steam outlet of the first-eighth-effect heating chambers is connected to their corresponding vapor-liquid separation chambers, and the secondary steam outlet pipes of the first-eighth-effect vapor-liquid separation chambers are respectively connected to the steam inlet of their next-effect heating chamber.
6. The sodium aluminate solution eight-effect two-stage evaporator assembly according to claim 5, characterized in that: The secondary steam outlet pipelines of the I-VI stage flash evaporators are respectively connected to the II-VIII effect separation chambers; a water cooler and a vacuum pump are connected to the steam outlet pipeline of the VII effect vapor-liquid separation chamber.
7. The sodium aluminate solution eight-effect two-stage evaporator assembly according to claim 6, characterized in that: The primary condensate from the I-effect heating chamber is collected via a primary condensate tank and a primary condensate pump; the secondary condensate from the II-effect, III-effect, IV-effect, V-effect, VI-effect, VII-effect, and VIII-effect heating chambers is combined and collected via a secondary condensate tank and a secondary condensate pump.
8. The sodium aluminate solution eight-effect two-stage evaporator assembly according to claim 7, characterized in that: The mother liquor circulating in the first concentration branch directly enters the VI-effect heating chamber, and then sequentially enters the V-effect heating chamber, IV-effect heating chamber, III-effect heating chamber, II-effect heating chamber, and I-effect heating chamber before entering the I-stage flash evaporator; the mother liquor circulating in the second concentration branch directly enters the VIII-effect heating chamber and then enters the VII-effect heating chamber in countercurrent operation.
9. The sodium aluminate solution eight-effect two-stage evaporator assembly according to claim 8, characterized in that: After entering the first concentration branch, the product sequentially enters the second, third, fourth, fifth, and sixth stage flash evaporators.
10. The sodium aluminate solution eight-effect two-stage evaporator assembly according to claim 2, characterized in that: A discharge pump is installed on the finished product recycling pipeline.