A continuous evaporation and continuous desalting device for soapmaking waste liquid

Abstract

The application discloses a continuous evaporation and continuous desalination device for soap-making waste liquid, and aims to solve the problem of low treatment efficiency of saponification waste water in the prior art, in which solid sodium chloride is continuously crystallized and separated, resulting in poor flowability of the material, and the solid sodium chloride needs to be periodically discharged and separated, and the evaporation operation needs to be stopped in the process, thereby causing the problem of low treatment efficiency of saponification waste water. The application is characterized in that the bottom of the three-effect evaporation chamber is communicated with a separation and filtration device, and a multifunctional filter is used to separate salt and glycerol, so that the salt in the soap-making waste liquid can be continuously separated in the three-effect evaporation chamber and continuously separated in the multifunctional filter, thereby improving the treatment efficiency of saponification waste water; solid sodium chloride is prevented from accumulating in the equipment and pipelines, and fouling of the equipment and pipelines is basically avoided through forced circulation and dilution of the reflux of the coarse glycerol after desalination, the heat exchange efficiency of the equipment is improved, the cleaning operation of the equipment is reduced, and the energy consumption is also reduced.

Description

A continuous evaporation and desalination device for soap making waste liquid Technical Field

[0001] This invention relates to the field of soap-making wastewater treatment technology, and more specifically, to a continuous evaporation and continuous desalination device for soap-making wastewater. Background Technology

[0002] The development of soap-making technology has progressed from large-scale saponification to continuous saponification, and finally to the currently dominant high-pressure hydrolysis of oils and fats and neutralization of fatty acids. Because soap-making is a gradual process, large-scale and continuous saponification processes still constitute a significant portion of the technology. Both large-scale and continuous saponification processes generate a large amount of soap-making waste liquid, which mainly contains glycerol, water, sodium chloride, and small amounts of impurities such as gums and fatty substances. Glycerol, a byproduct of the soap-making industry, has high application value. To obtain high-quality glycerol, the waste liquid needs to undergo pretreatment, evaporation and concentration, distillation and refining, and decolorization and filtration to obtain the finished glycerol. The pretreatment process removes impurities such as gums and fatty substances from the waste liquid, resulting in a purified waste liquid. The evaporation and concentration process evaporates the water in the purified waste liquid to increase the glycerol concentration and removes the crystalline sodium chloride that precipitates during the evaporation and concentration process, obtaining crude glycerol with a purity of over 80%. The distillation and refining process removes the remaining impurities and water, and after decolorization and filtration, obtains high-purity, high-quality finished glycerol.

[0003] Traditional saponification wastewater evaporation and concentration processes employ a double-effect + single-effect intermittent evaporation process. First, double-effect evaporation concentrates the soap-making waste liquid (glycerol content approximately 15%) to about 40%, then single-effect evaporation brings it to approximately 80% concentration. During this evaporation and concentration process, as water evaporates and the volume decreases, dissolved sodium chloride continuously crystallizes and precipitates. As the solid sodium chloride content increases, the material's fluidity decreases, and the heat exchange effect deteriorates, impacting production efficiency. Therefore, the material needs to be periodically discharged. The precipitated solid sodium chloride settles in a salt tank at the bottom of the evaporation chamber, is periodically pressed out, and after centrifugation, is recycled back to the saponification process.

[0004] In the double-effect + single-effect intermittent evaporation process, due to the evaporation of water, solid sodium chloride continuously crystallizes and precipitates, resulting in increasingly poor material flowability. It is necessary to periodically remove and separate the solid sodium chloride, during which the evaporation operation must be stopped. Therefore, the traditional evaporation process is an intermittent production process with a series of drawbacks, mainly as follows:

[0005] 1) The intermittent evaporation process combining double-effect and single-effect evaporation has high energy consumption. Because a large amount of water needs to be evaporated during concentration, this step is the most energy-intensive in glycerin production. The secondary steam generated by the second evaporator in a double-effect process and the evaporator in a single-effect process also has latent heat, but traditional processes cannot reuse it; directly condensing and discharging it is equivalent to wasting some energy.

[0006] 2) The intermittent evaporation process of double-effect + single-effect involves repeated start-up and shutdown, and the vacuum system is constantly being turned on and off, resulting in high energy consumption.

[0007] 3) In the intermittent evaporation process of double-effect + single-effect, the precipitated solid sodium chloride is desalted by static sedimentation. This requires manual operation of periodic salt discharge, washing, and dissolving, which is labor-intensive. Moreover, due to the increase in glycerol concentration, the viscosity increases exponentially, resulting in the need for a large number of salt settling tanks, which occupy a lot of space.

[0008] 4) In the intermittent evaporation process of double-effect + single-effect, the precipitated solid sodium chloride will be adsorbed and accumulated on the heating coil of the evaporator, resulting in low heat exchange efficiency of the equipment.

[0009] 5) Evaporators with scale buildup need to be washed regularly with fine wastewater to remove the crystallized salts remaining on the tank walls and heating coils. This process is labor-intensive, labor-intensive, and has a poor operating environment. Summary of the Invention

[0010] This invention overcomes the problem in existing technologies where solid sodium chloride continuously crystallizes and precipitates during the treatment of saponification wastewater, leading to increasingly poor material flowability and the need for periodic discharge and separation of solid sodium chloride. This process requires stopping the evaporation operation, resulting in low treatment efficiency for saponification wastewater. This invention provides a continuous evaporation and desalination device for soap-making wastewater. It can perform continuous evaporation and desalination, and transfer the continuously precipitated salt to a multi-functional filter for solid-liquid separation. This ensures that the desalination and salt precipitation processes do not interfere with each other, maintaining a continuous desalination and evaporation process, thereby improving the efficiency of saponification wastewater treatment.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a continuous evaporation and continuous desalination device for soap-making waste liquid, comprising:

[0012] The system includes a single-effect heater and a single-effect evaporation chamber. The upper part of the single-effect heater is connected to the single-effect evaporation chamber. The bottom of the single-effect evaporation chamber is provided with a first outlet and a second outlet, and the first outlet is connected to the bottom of the single-effect heater.

[0013] The double-effect heater and the double-effect evaporation chamber are connected. The second outlet is connected to the double-effect heater. The upper part of the double-effect heater is connected to the double-effect evaporation chamber. The bottom of the double-effect evaporation chamber is provided with a third outlet and a fourth outlet. The third outlet is connected to the bottom of the double-effect heater.

[0014] The triple-effect heater and triple-effect evaporation chamber are connected together. The fourth outlet is connected to the triple-effect heater. The upper part of the triple-effect heater is connected to the triple-effect evaporation chamber. The bottom of the triple-effect evaporation chamber is provided with a fifth outlet and a discharge port. The fifth outlet is connected to the bottom of the triple-effect heater.

[0015] A separation and filtration device is used to separate salt and glycerol; the outlet is connected to the separation and filtration device.

[0016] In this invention, the bottom of the triple-effect evaporation chamber is connected to the separation and filtration device, enabling continuous separation of salt and glycerol, improving the treatment efficiency of saponification wastewater; preventing the accumulation of solid sodium chloride in the equipment and pipelines, keeping the concentration of solid sodium chloride in the equipment and pipelines at a relatively low level, and through forced circulation and reflux dilution of crude glycerol after desalination, scaling of the equipment and pipelines is basically avoided, improving the heat exchange efficiency of the equipment, reducing equipment cleaning operations, and also reducing energy consumption.

[0017] As a preferred embodiment, the bottom of the triple-effect evaporator is provided with an eccentric conical hopper, the bottom of the eccentric conical hopper is provided with a straight cylinder, and the discharge port is located at the bottom of the straight cylinder.

[0018] The eccentric cone bucket is equipped with a ramp, which makes it easier for the crystallized salt to flow naturally into the collection box below; the straight cylinder is placed vertically, which allows the material to flow downward by its own gravity, minimizing material residue and reducing scaling on equipment and pipelines.

[0019] Preferably, a guide tube is provided at the center of the bottom of the triple-effect evaporator, and the fifth outlet is located at the bottom of the guide tube.

[0020] The guide pipe is designed to have a certain length within the triple-effect evaporation chamber to prevent bottom crystallized salt from flowing out. Furthermore, since the material enters tangentially along the edge of the evaporation effect, the concentration of crystallized salt is lowest at the center of the equipment. Therefore, placing the guide pipe in the center allows material with a lower salt concentration to flow out from the fifth outlet, thereby improving heat exchange efficiency.

[0021] Preferably, the separation and filtration device includes a collection box and a multi-functional filter. The material flows into the collection box from the discharge port, and then enters the multi-functional filter from the collection box for filtration.

[0022] Multifunctional filters can continuously and quickly remove salt, reducing the need for numerous static settling tanks and thus minimizing workshop space.

[0023] Preferably, the separation and filtration device also includes a crude glycerol storage tank. After the material is separated by the multi-functional filter, the liquid portion enters the crude glycerol storage tank, and then the liquid is sent to the triple-effect evaporation chamber through a return pump and return pipeline. The purpose of the crude glycerol storage tank is to ensure the continuous and stable return of the filtered crude glycerol to the system, to ensure the stability of the system, and to dilute the content of solid salts in the system, facilitating material flow.

[0024] The desalted material is sent back to the triple-effect evaporator for dilution, which reduces the solid salt content in the triple-effect evaporator, thereby significantly reducing the solid salt content in the triple-effect evaporator and basically eliminating the problems of salt accumulation in heat exchange tubes and blockage of control valves.

[0025] Preferably, the system also includes a water distributor and a heat pump. A first pipe is provided on the top of the first-effect evaporation chamber, which is connected to the second-effect heater and the heat pump respectively. Part of the steam in the first-effect evaporation chamber enters the second-effect heater through the first pipe, and the other part enters the heat pump through the first pipe and then enters the first-effect heater together with the fresh steam in the water distributor.

[0026] By adding a heat pump (2) and using fresh steam as the driving steam, some of the secondary steam generated in the first-effect evaporator (5) is reused. After being mixed with the heat pump through the first pipeline, it enters the first-effect heater, thereby allowing some of the secondary steam of the first-effect evaporator to be reused, which can further reduce the amount of steam used and improve the energy utilization rate.

[0027] Preferably, a second pipe is provided at the top of the double-effect evaporation chamber, and the second pipe is connected to the triple-effect heater.

[0028] By transporting the steam generated in the double-effect evaporator to the triple-effect heater through a second pipe, the steam can be reused, which can further reduce the amount of steam used and improve energy efficiency.

[0029] Preferably, an external circulation pump is installed between the fifth outlet and the triple-effect heater.

[0030] In the triple-effect evaporator, as water is continuously evaporated, sodium chloride in the soap-making waste liquid continuously crystallizes out in solid form, reducing the fluidity of the material. Therefore, an external circulation pump is installed in the triple-effect evaporator to force circulation and improve heat exchange efficiency.

[0031] Preferably, the system also includes a condensate tank and a heat exchanger. The heat exchanger is located at the inlet of the first-effect heater. After the condensate from the first-effect heater, the second-effect heater, and the third-effect heater flows into the condensate tank, the condensate and the material exchange heat in the heat exchanger, and the condensate preheats the material.

[0032] The condensate from the single-effect heater, the double-effect heater, and the triple-effect heater is all collected in a condensate tank. Then, it is first exchanged with soap-making waste liquid in a heat exchanger to recover heat and improve the utilization rate of thermal energy.

[0033] Preferably, a third pipe is installed at the top of the triple-effect evaporator, which is connected to the condenser, and the condenser is connected to a vacuum pump unit and a heat well.

[0034] The vacuum pump unit is used to maintain a vacuum in the triple-effect evaporator chamber, where the steam is condensed in the condenser, and the condensed water flows from the condenser into the hot well.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] (1) The triple-effect continuous evaporation system is adopted, and the steam generated by each stage of the evaporation system provides energy for the next stage of evaporation chamber, which improves the steam utilization efficiency and reduces energy consumption. The steam consumption per ton of soap-making waste liquid has been reduced from 0.60t to about 0.26t, which has a significant energy-saving effect.

[0037] (2) The entire production process is continuous, which avoids the drawbacks of multiple start-ups and shutdowns, reduces labor intensity, improves the operating environment, and also reduces energy consumption.

[0038] (3) The entire production process is continuous, and the system has achieved automated operation, which reduces the intensity of work and labor costs.

[0039] (4) Desalination is continuous, and solid sodium chloride will not accumulate in the equipment and pipelines. The concentration of solid sodium chloride in the equipment and pipelines is kept at a relatively low level. Through forced circulation and dilution by the reflux of crude glycerol after desalination, scaling of the equipment and pipelines is basically avoided, the heat exchange efficiency of the equipment is improved, the equipment cleaning operation is reduced, and energy consumption is also reduced.

[0040] (5) The use of a multi-functional filter (33) for continuous desalination reduces the number of static settling tanks and the workshop space. Attached Figure Description

[0041] Figure 1 is a schematic diagram of the overall process flow of the present invention;

[0042] Figure 2 is a front view of the triple-effect evaporation chamber of the present invention;

[0043] Figure 3 is a view along direction A in Figure 2;

[0044] Figure 4 is a cross-sectional view along the BB direction in Figure 2;

[0045] In the diagram: 1. Water distributor, 2. Heat pump, 3. First-effect heater, 4. First pipe, 5. First-effect evaporator, 6. Second pipe, 7. Second-effect heater, 8. Second-effect evaporator, 9. Third-effect heater, 10. Third-effect evaporator, 11. Third pipe, 12. Condenser, 13. Vacuum pump unit, 14. Heat exchanger, 15. Inlet pipe, 16. Second outlet, 17. First outlet, 18. Fourth outlet, 19. Third outlet, 20. Offset 21. Conical hopper, 22. External circulating pump, 23. Collection box, 24. Condensate pump, 25. Condensate tank, 26. Collection pump, 27. Return pipeline, 28. Return port, 29. Fifth outlet, 30. Straight cylinder, 31. Discharge port, 32. Condensate pipeline, 33. Hot well, 34. Multifunctional filter, 35. Crude glycerin temporary storage tank, 36. Return pump, 37. Material inlet, 38. Connecting flange, 39. Agitator, 30. Sight glass. Detailed Implementation

[0046] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings:

[0047] Example 1: Referring to Figures 1 to 4, a continuous evaporation and desalination device for soap making waste liquid includes: a heat exchanger 14, a first-effect heater 3 and a first-effect evaporation chamber 5, a second-effect heater 7 and a second-effect evaporation chamber 8, a third-effect heater 9 and a third-effect evaporation chamber 10, and a separation and filtration device.

[0048] The heating medium of the first-effect heater 3 is steam. The upper part of the first-effect heater 3 is connected to the first-effect evaporation chamber 5. The bottom of the first-effect evaporation chamber 5 is provided with a first outlet 17 and a second outlet 16. After being preheated by the heat exchanger 14, the material enters the first-effect heater 3. After being heated in the first-effect heater 3, the material enters the first-effect evaporation chamber 5 for evaporation.

[0049] The first outlet 17 is connected to the bottom of the first-effect heater 3, so that a portion of the material in the first evaporation chamber returns to the first-effect heater 3 through the first outlet 17 to generate self-circulation, so that the material is continuously heated and evaporated in the first-effect heater 3.

[0050] The second outlet 16 is connected to the double-effect heater 7, so that another part of the material in the first-effect evaporation chamber 5 enters the double-effect heater 7 from the second outlet 16 for heating.

[0051] The upper part of the double-effect heater 7 is connected to the double-effect evaporation chamber 8; the material heated in the double-effect heater 7 will enter the double-effect evaporation chamber 8 for evaporation. The bottom of the double-effect evaporation chamber 8 is provided with a third outlet 19 and a fourth outlet 18.

[0052] The third outlet 19 is connected to the bottom of the double-effect heater 7, so that a portion of the material in the double-effect evaporation chamber 8 returns to the double-effect heater 7 through the third outlet 19 to generate self-circulation, and is then continuously heated and evaporated.

[0053] The fourth outlet 18 is connected to the triple-effect heater 9, so that another part of the material in the double-effect evaporation chamber 8 enters the triple-effect heater 9 from the fourth outlet 18 for heating.

[0054] The upper part of the triple-effect heater 9 is connected to the triple-effect evaporation chamber 10; the material heated in the triple-effect heater 9 will enter the triple-effect evaporation chamber 10 for evaporation. The bottom of the triple-effect evaporation chamber 10 is provided with a fifth outlet 28 and a discharge port 30.

[0055] The fifth outlet 28 is connected to the bottom of the triple-effect heater 9, and an external circulation pump 21 is installed between the fifth outlet 28 and the triple-effect heater 9; so that the material in the triple-effect evaporation chamber 10 returns to the triple-effect heater 9 through the fifth outlet 28 to generate self-circulation and continue to be heated and evaporated.

[0056] The separation and filtration device is used to separate salt and glycerol. The outlet 30 is connected to the separation and filtration device, and the material flows into the device from the outlet 30. The separation and filtration device includes a collection box 22 and a multi-functional filter 33. The material flows into the collection box 22 from the outlet 30, and then enters the multi-functional filter 33 for filtration. The multi-functional filter 33 can separate solid salt from the material.

[0057] The separation and filtration device also includes a coarse glycerol storage tank 34. The liquid portion of the material after separation by the multi-functional filter 33 enters the coarse glycerol storage tank 34, and then the liquid is sent to the triple-effect evaporator 10 through the return pump 35 and the return pipeline 26. This allows the filtered material to continuously circulate between the triple-effect evaporator 10 and the multi-functional filter 33.

[0058] The top of the first-effect evaporation chamber 5 is provided with a first pipe. The first pipe 4 is connected to the second-effect heater 7 and the heat pump 2 through two separate pipes. This allows part of the steam in the first-effect evaporation chamber 5 to enter the second-effect heater 7 through the first pipe 4, and the other part to enter the heat pump 2 through the first pipe 4 and then enter the first-effect heater 3 together with the fresh steam in the water distributor 1.

[0059] A second pipe 6 is installed at the top of the double-effect evaporator 8, and the second pipe 6 is connected to the triple-effect heater 9.

[0060] A third pipe 11 is installed at the top of the triple-effect evaporator 10. The third pipe 11 is connected to the condenser 12, and the condenser 12 is connected to the vacuum pump group 13 and the hot well 32. The vacuum pump group 13 is used to maintain a vacuum in the condenser 12. The steam is condensed in the condenser 12, and the condensed water flows from the condenser 12 into the hot well 32.

[0061] In addition, it also includes a condensate tank 24 and a heat exchanger 14. The heat exchanger 14 is located at the inlet of the first-effect heater 3. After the condensate from the first-effect heater 3, the second-effect heater 7 and the third-effect heater 9 flows into the condensate tank 24, it enters the heat exchanger through the action of the condensate pump 23 and exchanges heat with the material in the heat exchanger 14. The condensate preheats the material.

[0062] The working principle of this invention is as follows: Soap-making waste liquid is preheated by heat exchanger 14 and then enters the first-effect heater 3, where the heating medium is steam. After being heated in the first-effect heater 3, the soap-making waste liquid enters the first-effect evaporation chamber 5 for evaporation. Part of the steam generated by evaporation enters the second-effect heater 7, and part is extracted by heat pump 2 and mixed with fresh steam from water distributor 1 to serve as the heating steam for the first-effect heater 3.

[0063] Under the influence of temperature and pressure differences, part of the material in the first-effect evaporation chamber 5 will return to the first-effect heater 3 through the first outlet 17 to generate self-circulation, so that the material is continuously heated and evaporated in the first-effect heater 3. The other part of the material enters the second-effect heater 7 and the second-effect evaporation chamber 8 through the second outlet 16 to continue evaporation and concentration. The material also generates self-circulation between the second-effect heater 7 and the second-effect evaporation chamber 8 and then enters the third-effect heater 9 after continuous evaporation. The steam generated by the evaporation in the second-effect evaporation chamber 8 enters the third-effect heater 9.

[0064] The material enters the triple-effect heater 9 and the triple-effect evaporator 10 for further evaporation. In the triple-effect evaporator 10, as moisture is continuously evaporated, sodium chloride in the soap-making waste liquid continuously crystallizes out in solid form, reducing the material's fluidity. Therefore, an external circulation pump 21 is installed in the triple-effect evaporator 10 for forced circulation. A collection box 22 is located at the bottom of the triple-effect evaporator 10. The material in the collection box 22 is drawn out by the collection pump 25 and sent to the multi-functional filter 33 for the separation of liquid crude glycerol and solid sodium chloride.

[0065] The material containing solid sodium chloride at the bottom of the triple-effect evaporator is filtered and separated by the multi-functional filter 33. The liquid material enters the crude glycerol temporary storage tank 34, and is then sent back to the triple-effect evaporator 10 by the return pump 35 through the return pipeline 26. The triple-effect evaporator is equipped with a reflux port 27, and the return pipeline 26 is connected to the reflux port 27. This allows the filtered material to circulate continuously between the triple-effect evaporator 10 and the multi-functional filter 33, allowing the solid sodium chloride to be continuously filtered out, reducing the solid salt content in the triple-effect evaporator 10, reducing salt accumulation, and improving heat exchange efficiency. At the same time, crude glycerol with a glycerol concentration of over 80% is continuously discharged to the next process for distillation and purification.

[0066] The solid sodium chloride retained in the multi-functional filter 33 can be discharged as solid or dissolved in water to form brine for reuse in the previous saponification process, depending on production requirements.

[0067] By adding a heat pump 2, which uses fresh steam as the driving steam, some of the secondary steam generated in the first-effect evaporator 5 is mixed with the heat pump 2 via pipe 4 and then enters the first-effect heater 3. This allows some of the secondary steam in the first-effect evaporator 5 to be reused, which can further reduce the amount of steam used.

[0068] After the steam in the first-effect heater 3, the second-effect heater 7, and the third-effect heater 9 heats the material, condensate is generated. All the condensate is collected in the condensate tank 24. Then, it is first exchanged with soap-making waste liquid in the heat exchanger 14 to recover heat. Then it is stored in the storage tank. Part of it is used directly as washing brine and dissolved brine, and part of it is sent to other workshops as process water, thereby reducing the amount of industrial water and heating steam used and reducing wastewater discharge.

[0069] This invention has the following advantages: 1. It adopts triple-effect continuous evaporation, where the steam generated by each stage of the evaporation system provides energy for the next stage of evaporation, improving steam utilization efficiency and reducing energy consumption. The steam consumption per ton of soap-making waste liquid is reduced from approximately 0.60t to approximately 0.26t, resulting in significant energy savings.

[0070] 2. The entire production process is continuous, avoiding the drawbacks of multiple start-ups and shutdowns, reducing labor intensity, improving the operating environment, and reducing energy consumption.

[0071] 3. The entire production process is continuous, and the system has achieved automated operation, reducing labor intensity and labor costs.

[0072] 4. Desalination is continuous, and solid sodium chloride will not accumulate in the equipment and pipelines. The concentration of solid sodium chloride in the equipment and pipelines is kept at a relatively low level. Through forced circulation and dilution by the reflux of crude glycerol after desalination, scaling in the equipment and pipelines is basically avoided, which improves the heat exchange efficiency of the equipment, reduces the equipment cleaning operation, and also reduces energy consumption.

[0073] 5. The use of a multi-functional filter 33 for continuous desalination reduces the need for a large number of static settling tanks and minimizes workshop space.

[0074] Example 2: Referring to Figures 1 to 4, this example is similar in structure to Example 1, except that an eccentric conical hopper 20 is provided at the bottom of the triple-effect evaporator 10, and a straight cylinder 29 is provided at the bottom of the eccentric conical hopper 20. The discharge port 30 is located at the bottom of the straight cylinder 29. A guide pipe is provided at the center of the bottom of the triple-effect evaporator 10, and the fifth outlet 28 is located at the bottom of the guide pipe.

[0075] In the design process, to maximize the precipitation and separation of solid salt within the triple-effect evaporator 10, its design differs significantly from the previous two evaporator chambers. The bottom of the triple-effect evaporator 10 features an eccentric conical hopper 20, which is an eccentric reducer structure with a straight cylinder 29. The fifth outlet 28 is designed on the sloping surface of the reducer, located on the centerline of the triple-effect evaporator 10. The reflux port 27 is designed on the straight surface of the reducer, slightly higher than the upper edge of the guide pipe. The discharge port 30 is located at the bottom of the straight cylinder 29. This design ensures that most of the solid salt enters the collection box 22 below the triple-effect evaporator 10, improving production efficiency. Furthermore, it reduces the amount of solid salt entering the triple-effect heater 9 during forced circulation, thereby improving heat exchange efficiency.

[0076] Example 3: Referring to Figures 2 to 4, this example is similar in structure to Example 2. The side wall of the triple-effect evaporator 10 is provided with a material inlet 36, which is connected to the triple-effect heater 9. The material inlet 36 is arranged along the tangential direction of the side wall of the triple-effect evaporator 10.

[0077] The material inlet 36 of the triple-effect evaporator 10 is eccentrically designed. The feed pipe is installed at an eccentric position on the side wall of the evaporator, rather than at the center, so that the material inlet 36 is set along the tangential direction of the side wall of the triple-effect evaporator 10. Eccentric feeding can guide the material to form a swirling flow along the equipment wall within the triple-effect evaporator 10. Swirling flow has the following advantages: First, it can increase the flow velocity of the material and increase the evaporation efficiency. Second, it causes the crystalline salt in the material to leave the center of the evaporator under the action of centrifugal force, that is, away from the circulating material outlet located at the center, reducing the amount of crystalline salt in the circulating liquid and allowing most of the crystalline salt to efficiently precipitate to the discharge port at the bottom of the triple-effect evaporator 10. Third, eccentric feeding can make the material flow smooth, keep the liquid level stable, reduce foaming, and lower the COD of the hot well wastewater.

[0078] The bottom of the straight cylinder 29 and the eccentric cone 20 are connected by a connecting flange 37, which makes it easy to replace the straight cylinder 29.

[0079] The bottom side wall of the straight cylinder 29 is provided with an agitation port 38 arranged tangentially to it. A pipe is connected from the collecting pump 25 to the agitation port 38, so that the material can maintain its fluidity at the discharge port 30, avoid the accumulation of material in the straight cylinder 29, reduce the risk of blockage, and thus improve the cleanliness and production efficiency of the equipment.

[0080] The side wall of the triple-effect evaporation chamber 10 is also provided with an observation mirror 39, which allows the internal condition of the triple-effect evaporation chamber 10 to be observed through the observation mirror 39.

[0081] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications may be made without departing from the technical solutions described in the claims.

Claims

1. A continuous evaporation and desalination device for soap-making waste liquid, characterized in that, include: A single-effect heater and a single-effect evaporation chamber, with the upper part of the single-effect heater connected to the single-effect evaporation chamber; The bottom of the single-effect evaporation chamber has a first outlet and a second outlet. The first outlet is connected to the bottom of the single-effect heater. The second-effect heater and the second-effect evaporation chamber are connected, with the second outlet connected to the second-effect heater and the upper part of the second-effect heater connected to the second-effect evaporation chamber. The bottom of the second-effect evaporation chamber has a third outlet and a fourth outlet. The third outlet is connected to the bottom of the second-effect heater. The third-effect heater and the third-effect evaporation chamber are connected, with the fourth outlet connected to the third-effect heater and the upper part of the third-effect heater connected to the third-effect evaporation chamber. The bottom of the third-effect evaporation chamber has a fifth outlet and a discharge port. The fifth outlet is connected to the third-effect heater. The bottom of the heater is connected; the bottom of the triple-effect evaporator is provided with an eccentric cone hopper with an eccentric reducer, and the bottom of the eccentric cone hopper is provided with a straight cylinder, with the discharge port located at the bottom of the straight cylinder; the side wall of the triple-effect evaporator is provided with a material inlet, which is eccentrically positioned along the tangent of the side wall of the triple-effect evaporator; a guide pipe of a certain length is provided at the center of the bottom of the triple-effect evaporator, and the bottom side wall of the straight cylinder is provided with an agitator along its tangent; a reflux port is provided inside the triple-effect evaporator, and the reflux pipe is connected to the reflux port, which is located on the straight surface of the eccentric reducer and higher than the upper edge of the guide pipe; The fifth outlet is located at the bottom of the guide tube and on the sloping surface of the eccentric reducer; the separation and filtration device is used to separate salt and glycerin, and the discharge port is connected to the separation and filtration device.

2. The continuous evaporation and desalination device for soap-making waste liquid according to claim 1, characterized in that, The separation and filtration device includes a collection box and a multi-functional filter. The material flows into the collection box from the discharge port, and then enters the multi-functional filter for filtration.

3. The continuous evaporation and desalination device for soap-making waste liquid according to claim 2, characterized in that, The separation and filtration device also includes a crude glycerol storage tank. After the material is separated by the multi-functional filter, the liquid part enters the crude glycerol storage tank, and then the liquid is sent into the triple-effect evaporation chamber through the return pump and return pipeline.

4. The continuous evaporation and continuous desalination device for soap-making waste liquid according to any one of claims 1 to 3, characterized in that, It also includes a water distributor and a heat pump. The top of the first-effect evaporation chamber is equipped with a first pipe, which is connected to the second-effect heater and the heat pump respectively. Part of the steam in the first-effect evaporation chamber enters the second-effect heater through the first pipe, and the other part enters the heat pump through the first pipe and then enters the first-effect heater together with the fresh steam in the water distributor.

5. The continuous evaporation and continuous desalination device for soap-making waste liquid according to claim 4, characterized in that, A second pipe is installed at the top of the double-effect evaporator, and the second pipe is connected to the triple-effect heater.

6. The continuous evaporation and desalination device for soap-making waste liquid according to claim 4, characterized in that, An external circulation pump is installed between the fifth outlet and the triple-effect heater.

7. The continuous evaporation and continuous desalination device for soap-making waste liquid according to any one of claims 1 to 3, characterized in that, It also includes a condensate tank and a heat exchanger. The heat exchanger is located at the inlet of the first-effect heater. After the condensate from the first-effect heater, the second-effect heater and the third-effect heater flow into the condensate tank, the condensate and the material exchange heat in the heat exchanger. The condensate preheats the material.

8. The continuous evaporation and continuous desalination device for soap-making waste liquid according to any one of claims 1 to 3, characterized in that, A third pipe is installed at the top of the triple-effect evaporator, which is connected to the condenser. The condenser is connected to a vacuum pump unit and a heat well.

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