A device for concentrating lactic acid solutions containing large amounts of water

Abstract

The utility model discloses a kind of lactic acid solution concentration devices suitable for containing a large amount of water, including a set of MVR three-effect evaporator and two sets of thin film evaporator, the MVR three-effect evaporator includes one-effect evaporator, two-effect evaporator, three-effect evaporator, one-effect evaporation chamber, two-effect evaporation chamber and three-effect evaporation chamber, one-effect evaporation chamber is connected with one-effect evaporator and two-effect evaporator of both sides by pipeline, two-effect evaporation chamber is connected with two-effect evaporator and three-effect evaporator of both sides by pipeline.The water vapor outlet of one-effect evaporation chamber is connected to the jacket inlet of two-effect evaporator by pipeline, the water vapor outlet of two-effect evaporation chamber is connected to the jacket inlet of three-effect evaporation chamber by pipeline, after each evaporation chamber evaporates the moisture of material itself, in the form of water vapor goes to lower evaporator as heat source evaporates the moisture of material of next level evaporation chamber, three-effect evaporator except first effect, the rest of each effect does not need to use live steam, can reduce the use cost of live steam.

Description

Technical Field

[0001] This utility model relates to the field of concentration equipment technology, specifically to a device for concentrating lactic acid solutions containing a large amount of water. Background Technology

[0002] In the production of organic acids such as lactic acid, the initial fermentation broth or extract typically contains a large amount of water (often as high as 80-95%). Concentration and dehydration are essential steps to obtain high-purity products. Currently, widely used industrial concentration technologies mainly include multi-effect evaporation, mechanical vapor recompression (MVR) evaporation, and scraped film evaporation. Existing concentration equipment generally suffers from insufficient heat energy utilization, primarily due to: the live steam being directly discharged after use in the first effect of a triple-effect evaporator; the water evaporated from the solution itself being directly discharged after condensation in the condenser; and scraped film evaporators being used only once per batch of material. Utility Model Content

[0003] The technical problem this invention aims to solve is to overcome the shortcomings of existing systems and provide a device suitable for concentrating lactic acid solutions containing large amounts of water. The secondary steam generated in the first-effect evaporator is directly used as a heat source to supply the second-effect evaporator, and the secondary steam generated in the second-effect evaporator is then supplied to the third-effect evaporator. Thanks to this design, only the first-effect evaporator needs to consume fresh live steam; the second and third effects rely entirely on the secondary steam generated in the preceding effects as their heat source. This significantly reduces the total live steam demand of the entire three-effect evaporation system, directly lowering the core operating cost—steam cost—and effectively solving the problems described in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a device for concentrating lactic acid solutions containing a large amount of water, comprising one set of MVR triple-effect evaporators and two sets of thin-film evaporators. The MVR triple-effect evaporator includes a first-effect evaporator, a second-effect evaporator, a third-effect evaporator, a first-effect evaporation chamber, a second-effect evaporation chamber, and a third-effect evaporation chamber. The first-effect evaporation chamber is connected to the first-effect and second-effect evaporators on both sides via pipelines. The second-effect evaporation chamber is connected to the second-effect and third-effect evaporators on both sides via pipelines. The third-effect evaporation chamber is connected to the third-effect evaporators on both sides and a first condenser via pipelines. The first condenser, a first condensate tank, and a first transfer tank are connected sequentially via pipelines. The first set of two thin-film evaporators includes a first scraped evaporator and a second condenser connected via pipelines. The second condenser is connected to a second condensate tank. The second set includes a second scraped evaporator and a third condenser connected via pipelines. The third condenser is connected to a third condensate tank.

[0005] As a preferred embodiment of this utility model, the feed end of the first-effect evaporator is connected to the preheater via a pipeline, and the preheater is connected to the first feed pump; the jacket of the preheater is connected to the steam outlet of the first-effect evaporation chamber via a pipeline.

[0006] As a preferred embodiment of this utility model, the first-effect evaporator, the second-effect evaporator, and the third-effect evaporator are all equipped with glass sight glasses.

[0007] As a preferred embodiment of this utility model, a first gas-liquid separator is provided between the double-effect evaporator and the triple-effect evaporator, and a second gas-liquid separator is provided between the triple-effect evaporator and the first condenser.

[0008] As a preferred embodiment of this utility model, a fourth circulation pump is provided on the pipeline between the first scraper evaporator and its material collection tank.

[0009] As a preferred embodiment of this utility model, the second condensate tank is connected to a second condensate pump and a second vacuum pump via pipelines, and the third condensate tank is connected to a third condensate pump and a third vacuum pump via pipelines.

[0010] Compared with existing technologies, the beneficial effects of this invention are as follows: the steam outlet of the first-effect evaporator is connected to the jacket inlet of the second-effect evaporator via a pipeline, and the steam outlet of the second-effect evaporator is connected to the jacket inlet of the third-effect evaporator via a pipeline. After evaporating the moisture from the material itself in each evaporator, the steam is sent to the next-stage evaporator as a heat source to evaporate the moisture from the material in the next stage evaporator. Except for the first effect, the other effects of the three-effect evaporator do not require the use of live steam, thus reducing the cost of using live steam. Through the reuse of live steam, the utilization of steam evaporated from the material, and the cyclical use of individual equipment, thermal efficiency is improved while ensuring product quality, thereby reducing equipment investment and operating costs.

[0011] A fourth circulation pump is installed on the pipeline between the first scraper evaporator and its material collection tank. After the material falls from the first scraper evaporator into its material collection tank, a portion of the liquid is forced back into the first scraper evaporator by the fourth circulation pump. This maximizes the utilization of the steam heat of a single device and reduces the initial investment in the equipment. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the triple-effect evaporator of this utility model;

[0013] Figure 2 This is a schematic diagram of the structure of the thin-film evaporator of this utility model.

[0014] In the diagram: 1. Preheater; 2. First-effect evaporator; 3. Second-effect evaporator; 4. Third-effect evaporator; 5. First condenser; 6. First scraped evaporator; 7. Second condenser; 8. Second scraped evaporator; 9. Third condenser; 10. First-effect evaporation chamber; 11. Second-effect evaporation chamber; 12. Third-effect evaporation chamber; 13. First condensate tank; 14. First transfer tank; 15. Second condensate tank; 16. Second transfer tank; 17. Third condensate tank; 18. Third transfer tank; 19. First gas-liquid separator; 20. Second gas-liquid separator, 21 First feed pump, 22 First circulation pump, 23 First transfer pump, 24 Second circulation pump, 25 Second transfer pump, 26 Third circulation pump, 27 First discharge pump, 28 First vacuum pump, 29 First condensate pump, 30 Second feed pump, 31 Second discharge pump, 32 Second condensate pump, 33 Second vacuum pump, 34 Third feed pump, 35 Third discharge pump, 36 Third condensate pump, 37 Third vacuum pump, 38 Fourth circulation pump. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] Please see Figure 1-2 This utility model provides a technical solution: a device for concentrating lactic acid solutions containing a large amount of water, comprising a set of MVR triple-effect evaporators and two sets of thin-film evaporators. The MVR triple-effect evaporator includes a first-effect evaporator 2, a second-effect evaporator 3, a third-effect evaporator 4, a first-effect evaporation chamber 10, a second-effect evaporation chamber 11, and a third-effect evaporation chamber 12. The first-effect evaporation chamber 10 is connected to the first-effect evaporator 2 and the second-effect evaporator 3 on both sides via pipelines. The second-effect evaporation chamber 11 is connected to the second-effect evaporator 3 and the third-effect evaporator 4 on both sides via pipelines. The third-effect evaporation chamber 12 is connected to the third-effect evaporator 4 on both sides and the first condenser 5 via pipelines. The first condenser 5, the first condensate tank 13, and the first transfer tank 14 are connected sequentially via pipelines. The steam outlet of the first-effect evaporator 10 is connected to the jacket inlet of the second-effect evaporator 3 via a pipeline. The steam outlet of the second-effect evaporator 11 is connected to the jacket inlet of the third-effect evaporator 12 via a pipeline. After the moisture of the material itself is evaporated in each evaporator, it is sent to the next-stage evaporator in the form of steam as a heat source to evaporate the moisture of the material in the next-stage evaporator. Except for the first effect, the other effects of the three-effect evaporator do not need to use live steam, which can reduce the cost of using live steam.

[0017] A first circulation pump 22 is installed on the pipeline between the first-effect evaporator 2 and the first-effect evaporation chamber 10. A second circulation pump 24 is installed on the pipeline between the second-effect evaporator 3 and the second-effect evaporation chamber 11. A third circulation pump 26 is installed on the pipeline between the four third-effect evaporation chambers 12 of the third-effect evaporator. The material can be forcibly sent back to the corresponding evaporator through each circulation pump, so as to maximize the utilization of the steam heat of a single device.

[0018] The first set of two thin-film evaporators includes a first scraped evaporator 6 and a second condenser 7 connected by pipelines. The second condenser 7 is connected to a second condensate tank 15. The second set includes a second scraped evaporator 8 and a third condenser 9 connected by pipelines. The third condenser 9 is connected to a third condensate tank 17. A fourth circulation pump 38 is installed on the pipeline between the first scraped evaporator 6 and its material collection tank. After the material falls from the first scraped evaporator 6 into its material collection tank, a portion of the liquid is forcibly pumped back into the first scraped evaporator 6 by the fourth circulation pump 38. This maximizes the utilization of the steam heat of a single device and reduces the initial investment in the equipment. This design requires that the material throughput be well matched with the front end so that the material discharged from the first thin-film scraped evaporator only needs to pass through the next stage of thin film evaporator once more before being discharged.

[0019] This application improves thermal efficiency while ensuring product quality by reusing live steam, utilizing water vapor evaporated from materials, and recycling individual equipment, thereby reducing equipment investment and operating costs.

[0020] In a preferred embodiment, the feed end of the first-effect evaporator 2 is connected to the preheater 1 via a pipeline, and the preheater 1 is connected to the first feed pump 21. The jacket of the preheater 1 is connected to the steam outlet of the first-effect evaporation chamber 10 via a pipeline. After the first-effect evaporator 2 is used, the live steam enters the jacket inlet of the preheating heat exchanger from the jacket outlet of the first-effect evaporator 2, preheating the material at room temperature to about 45 degrees Celsius. The live steam is reused, and the preheated material enters the subsequent process, which can reduce the subsequent steam consumption and reduce the energy consumption of the equipment.

[0021] In the preferred embodiment, each of the first-effect evaporator 2, the second-effect evaporator 3, and the third-effect evaporator 4 is equipped with a glass sight glass, allowing operators to directly observe the flow state of the material inside each evaporator and determine whether the concentration process is running smoothly.

[0022] In a preferred embodiment, a first gas-liquid separator 19 is provided between the double-effect evaporator 11 and the triple-effect evaporator 4, and a second gas-liquid separator 20 is provided between the triple-effect evaporator 12 and the first condenser 5. The gas-liquid separator allows lactic acid that is accidentally carried away during the vacuuming process to be condensed in the gas-liquid separator and then flowed back to the evaporator, thereby reducing the loss of lactic acid.

[0023] In a preferred embodiment, the second condensate tank 15 is connected to a second condensate pump 32 and a second vacuum pump 33 via pipelines, and the third condensate tank 17 is connected to a third condensate pump 36 and a third vacuum pump 37 via pipelines. The vacuum pumps establish and precisely control the required negative pressure (vacuum) environment for the corresponding scraped evaporators (the first scraped evaporator 6 corresponds to the second condensate tank 15, and the second scraped evaporator 8 corresponds to the third condensate tank 17). Vacuum degree is a key factor affecting evaporation temperature. For heat-sensitive lactic acid, a higher evaporation temperature can be maintained under a lower vacuum degree (higher absolute pressure); low-temperature evaporation (boiling point reduction) can be achieved under a higher vacuum degree (lower absolute pressure).

[0024] The condensate pump continuously and automatically discharges the condensate collected in the corresponding condensate tank (obtained by condensing secondary steam generated by the scraped evaporator through condensers 7 and 9) from the system, preventing the condensate tank level from becoming too high. An excessively high level can submerge the condenser's heat exchange tube bundle or steam inlet, hindering steam condensation and leading to increased system back pressure, vacuum disruption, a sharp drop in evaporation efficiency, or even system shutdown. Simultaneously, it promptly discharges low-temperature condensate, ensuring sufficient space and good heat exchange surfaces within the condenser to contact newly entering steam, maximizing latent heat recovery efficiency. Achieving automatic and stable condensate discharge without manual intervention or intermittent operation is one of the fundamental guarantees for the long-term, unattended continuous operation of the entire system.

[0025] The pumps, evaporators, condensers, etc. used in this application are all commonly used electronic components in the prior art. They are powered by an external power source and controlled by an external control switch. Their specific structures, working principles, control methods, and circuit connections are all well-known technologies and will not be described in detail here.

[0026] The parts not disclosed in this utility model are all prior art, and their specific structures, materials, and working principles will not be described in detail. Although embodiments of this utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this utility model, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A device for concentrating lactic acid solutions containing a large amount of water, characterized in that: The system includes one MVR triple-effect evaporator and two thin-film evaporators. The MVR triple-effect evaporator comprises a first-effect evaporator (2), a second-effect evaporator (3), a third-effect evaporator (4), a first-effect evaporation chamber (10), a second-effect evaporation chamber (11), and a third-effect evaporation chamber (12). The first-effect evaporation chamber (10) is connected to the first-effect evaporator (2) and the second-effect evaporator (3) on both sides via pipes. The second-effect evaporation chamber (11) is connected to the second-effect evaporator (3) and the third-effect evaporator (4) on both sides via pipes. The third-effect evaporation chamber (12) is connected to the third-effect evaporation chamber (12) via pipes. The road is connected to the triple-effect evaporator (4) and the first condenser (5) on both sides. The first condenser (5), the first condensate tank (13) and the first transfer tank (14) are connected in sequence through pipelines. The first set of two thin-film evaporators includes a first scraped evaporator (6) and a second condenser (7) connected through pipelines. The second condenser (7) is connected to the second condensate tank (15). The second set includes a second scraped evaporator (8) and a third condenser (9) connected through pipelines. The third condenser (9) is connected to the third condensate tank (17).

2. The apparatus for concentrating lactic acid solutions containing a large amount of water according to claim 1, characterized in that: The feed end of the first-effect evaporator (2) is connected to the preheater (1) through a pipeline, and the preheater (1) is connected to the first feed pump (21); the jacket of the preheater (1) is connected to the steam outlet of the first-effect evaporation chamber (10) through a pipeline.

3. The apparatus for concentrating lactic acid solutions containing a large amount of water according to claim 1, characterized in that: Each of the first-effect evaporator (2), the second-effect evaporator (3), and the third-effect evaporator (4) is equipped with a glass sight glass.

4. The apparatus for concentrating lactic acid solutions containing a large amount of water according to claim 1, characterized in that: A first gas-liquid separator (19) is provided between the double-effect evaporator (11) and the triple-effect evaporator (4), and a second gas-liquid separator (20) is provided between the triple-effect evaporator (12) and the first condenser (5).

5. A lactic acid solution concentration device according to claim 1, characterized in that: A fourth circulation pump (38) is installed on the pipeline between the first scraper evaporator (6) and its material collection tank.

6. The apparatus for concentrating lactic acid solutions containing a large amount of water according to claim 1, characterized in that: The second condensate tank (15) is connected to the second condensate pump (32) and the second vacuum pump (33) via pipelines, and the third condensate tank (17) is connected to the third condensate pump (36) and the third vacuum pump (37) via pipelines.

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