A device for purifying sweet water by hydrolysis of oils

Abstract

This utility model relates to a device for purifying sweet water from oil hydrolysis, comprising: an oil separator, a mixed oil tank, a primary heat exchanger, a secondary heat exchanger, a flash tower, a compressor, a stirred tank, a filter, a glycerin tank, a colloid tank, and a clean water tank; wherein, the oil separator is configured with a dual parallel structure, with the lower left outlet of the oil separator connected to the mixed oil tank, and the lower right outlet connected sequentially to the primary heat exchanger, the secondary heat exchanger, and the middle of the flash tower via a pump; the top of the flash tower is connected to the compressor inlet, and the compressor outlet is connected to the heat source side of the primary heat exchanger to form a steam heat energy recovery loop; the bottom outlet of the flash tower is connected to the top of the stirred tank via a pump, and the bottom outlet of the stirred tank is connected to the filter inlet via a pump; the filter has dual outlets, with the upper outlet connected to the glycerin tank, from which glycerin is discharged, and the lower outlet connected to the colloid tank, from which colloid is discharged; a circulation branch is provided after the pump at the bottom of the flash tower, connected to the feed inlet of the primary heat exchanger; the cold source side outlet of the primary heat exchanger is connected to the clean water tank, from which clean water is discharged.

Description

Technical Field

[0001] This utility model belongs to the field of oleochemicals, specifically relating to a device for purifying sweet water from oleohydrolysis. Background Technology

[0002] In the oleochemical industry, the processes and conditions for hydrolyzing various oils and fats vary greatly, ranging from enzymatic hydrolysis at room temperature to catalytic superheated steam hydrolysis at 300°C, and from atmospheric pressure to high pressure of 20 MPa. Common oils and fats are often produced into fatty acids through various direct hydrolysis methods. If saponification is followed by acidification, colloids are easily formed; acidification can cause emulsification and requires a large amount of brine. Therefore, hydrolysis is the mainstream technology. Since oil and fat hydrolysis is an equilibrium reaction, its reversibility means that hydrolysis cannot be complete. Lipids also participate in the reaction during hydrolysis, becoming more hydrophilic and viscous. Ultimately, the oil and fat are hydrolyzed into fatty acids, with smaller molecules, a thinner oil phase, and lower viscosity. Residual oils are carried away by impurities and discharged into the sweet water system.

[0003] The oily wastewater produced in industrial fatty acid production is cloudy, viscous, and contains foamy oil residue. It adheres to glass walls, exhibits poor density and polarity, and is difficult to process using conventional methods such as centrifugation or flotation due to its high COD (Chemical Oxygen Demand), pungent odor, and the presence of impurities such as oils, glycerol, and colloids. This prevents it from undergoing conventional biological treatment. Furthermore, the high lipid and glycerol content in the wastewater represents valuable resources and should be recovered. The recovered water can also be reused for hydrolysis to conserve external water resources. Therefore, an integrated device is urgently needed to achieve the complete resource-based purification and recovery of the wastewater components. Utility Model Content

[0004] To address the aforementioned problems in the existing technology, this utility model provides a device for purifying sweet water from oil hydrolysis. The technical problem to be solved by this utility model is achieved through the following technical solution: This utility model provides a device for purifying sweet water from oil hydrolysis, comprising: an oil separator, a mixed oil tank, a primary heat exchanger, a secondary heat exchanger, a flash evaporator, a compressor, a stirring vessel, a filter, a glycerin tank, a colloid tank, and a clear water tank; wherein, the oil separator is configured with a dual parallel structure, the lower left outlet of the oil separator is connected to the mixed oil tank, and the lower right outlet is connected sequentially to the primary heat exchanger, the secondary heat exchanger, and the middle of the flash evaporator via a pump; the top of the flash evaporator is connected to the compressor inlet, and the compressor outlet is connected to the heat exchanger of the primary heat exchanger. A steam heat energy recovery loop is formed on the source side; the bottom outlet of the flash tower is connected to the top of the stirred tank via a pump, and the bottom outlet of the stirred tank is connected to the inlet of the filter via a pump; the filter has two outlets, the upper outlet is connected to the glycerin tank, and glycerin is discharged from the outlet of the glycerin tank, and the lower outlet is connected to the colloid tank, and colloid is discharged from the outlet of the colloid tank; a circulation branch is provided after the pump at the bottom of the flash tower, which is connected to the feed inlet of the first-stage heat exchanger; the cold source side outlet of the first-stage heat exchanger is connected to the clean water tank, and clean water is discharged from the outlet of the clean water tank.

[0005] In one embodiment of this utility model, the oil distribution tank is a vertical tank with a heating coil at the bottom and a float oil discharge mechanism and a radar level gauge at the top.

[0006] In one embodiment of this utility model, the float-type oil discharge mechanism includes a float and a hose, wherein the float is connected to the lower left outlet of the oil distributor via the hose, and the lower left outlet of the oil distributor is an oil discharge port.

[0007] In one embodiment of this utility model, the mixed oil tank is a horizontal tank or a small vertical tank, positioned at a low level, with the highest liquid level being less than half the height of the oil distribution tank.

[0008] In one embodiment of this utility model, the primary heat exchanger is a shell-and-tube heat exchanger, and the secondary heat exchanger is an electrically heated or shell-and-tube heat exchanger.

[0009] In one embodiment of this utility model, the flash tower is a two-stage packed atmospheric tower. The lower section packing is DN50 Pall rings, and the filling height of the lower section packing is 3 to 5 times the inner diameter of the flash tower. The upper section packing is 250Y structured packing, and the filling height of the upper section packing is 1 to 2 times the inner diameter of the flash tower.

[0010] In one embodiment of this utility model, the compressor is a Roots-type steam compressor, and the steam extraction rate is 1 to 1.5 times the maximum design evaporation rate of the flash tower.

[0011] In one embodiment of this utility model, the stirring vessel is an atmospheric pressure reactor with a powder feeding hopper at the top for adding activated carbon powder.

[0012] In one embodiment of this utility model, the filter is a dual-group parallel interactive regeneration activated carbon filter bed, which achieves sewage discharge and regeneration through automatic backwashing.

[0013] In one embodiment of this utility model, the glycerin tank, the colloid tank, and the water tank are all small vertical tanks of the same specifications, and the water output from the water tank is recycled for oil hydrolysis.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: This utility model's oil hydrolysis sweet water purification device recovers impurities from sweet water that was originally directly discharged and difficult to biodegrade through thermal sedimentation, produces clean water by recovering steam heat energy through flash evaporation and mechanical compression, and produces glycerol and colloids through activated carbon filtration. It realizes the classification, purification, recycling and reuse of various resources, low-energy consumption and zero-waste production, and has a comprehensive improvement on the resources, environmental protection and economy of fatty acid production industry.

[0015] The above description is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a sweet water purification device for oil hydrolysis provided in an embodiment of this utility model.

[0017] Attached reference numerals: 1-Oil separator; 2-Miscellaneous oil tank; 3-First-stage heat exchanger; 4-Second-stage heat exchanger; 5-Flash tower; 6-Compressor; 7-Agitator; 8-Filter; 9-Glycerin tank; 10-Colloid tank; 11-Clear water tank. Detailed Implementation

[0018] To further illustrate the technical means and effects adopted by this utility model to achieve its intended purpose, the following detailed description of an oil hydrolysis sweet water purification device based on this utility model is provided in conjunction with the accompanying drawings and specific embodiments.

[0019] The foregoing and other technical contents, features, and effects of this utility model will be clearly presented in the following detailed description of the specific embodiments with reference to the accompanying drawings. Through the description of the specific embodiments, a more in-depth and specific understanding can be gained of the technical means and effects adopted by this utility model to achieve the intended purpose. However, the accompanying drawings are only provided for reference and illustration and are not intended to limit the technical solution of this utility model.

[0020] Example 1 The sweet water produced after industrial fatty acid production contains lipids, glycerol, and water, all of which are valuable resources and should be recycled. This invention provides a sweet water purification device for oil hydrolysis, which can be connected in series at the end of the fatty acid production line for the resource-based purification and recycling of the discharged sweet water. Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of a sweet water purification device for oil hydrolysis provided in an embodiment of this utility model.

[0021] In this embodiment, a sweet water purification device for oil hydrolysis includes: an oil separator 1, a mixed oil tank 2, a primary heat exchanger 3, a secondary heat exchanger 4, a flash evaporator 5, a compressor 6, a stirring vessel 7, a filter 8, a glycerin tank 9, a colloid tank 10, and a clean water tank 11; wherein, the oil separator 1 is configured as a double parallel structure, with the lower left outlet of the oil separator 1 connected to the mixed oil tank 2, and the lower right outlet connected sequentially to the primary heat exchanger 3, the secondary heat exchanger 4, and the middle of the flash evaporator 5 via a pump; the top of the flash evaporator 5 is connected to the inlet of the compressor 6, and the outlet of the compressor 6 is connected to the heat source side of the primary heat exchanger 3 to form a steam evaporator. In the steam heat recovery loop, steam is condensed in the first-stage heat exchanger 3 to form condensate. The condensate is discharged into the clean water tank 11 through a drain valve, and the trace amount of uncondensed steam is returned to the flash tower 5. The bottom outlet of the flash tower 5 is connected to the top of the stirred tank 7 via a pump, and the bottom outlet of the stirred tank 7 is connected to the inlet of the filter 8 via a pump. The filter 8 has two outlets: the upper outlet is connected to the glycerin tank 9, and the glycerin is discharged from the outlet of the glycerin tank 9; the lower outlet is connected to the colloid tank 10, and the colloid is discharged from the outlet of the colloid tank 10. The cold source side outlet of the first-stage heat exchanger 3 is connected to the clean water tank 11, and the clean water is discharged from the outlet of the clean water tank 11.

[0022] In an optional implementation, a circulation branch is provided after the bottom pump of the flash tower 5, which is connected to the feed inlet of the first-stage heat exchanger 3. The concentrated liquid is refluxed and reheated through the circulation branch to quickly establish a temperature gradient in the tower and shorten the system start-up time.

[0023] In one optional embodiment, the oil distribution tank 1 is a vertical tank with a heating coil at the bottom and a float-type oil discharge mechanism and a radar level gauge at the top. For example, the top of the oil distribution tank 1 is equipped with a radar level gauge and a breather valve with a flame arrester; there are maintenance manholes at the top and lower right; an internal ladder is provided; and external ladder railings and lightning protection / static electricity grounding safety accessories may be provided. The oil distribution tank 1 is also equipped with an explosion-proof self-priming centrifugal pump.

[0024] In one optional embodiment, the float-type oil discharge mechanism includes a float and a hose, with the float connected to the lower left outlet of the oil distributor 1 via the hose, wherein the lower left outlet of the oil distributor 1 is the oil discharge port.

[0025] In one optional embodiment, the mixed oil tank 2 is a horizontal tank or a small vertical tank, positioned at a low level, with the highest liquid level below half the height of the oil distribution tank 1. For example, the mixed oil tank 2 is equipped with a breather valve with a flame arrester and safety accessories for lightning protection and anti-static grounding, and a local remote level gauge, with the level gauge automatically controlling the bottom discharge pump. The bottom of the mixed oil tank 2 is equipped with an explosion-proof screw pump.

[0026] In one alternative implementation, the primary heat exchanger 3 is a shell-and-tube heat exchanger, and the secondary heat exchanger 4 is an electrically heated or shell-and-tube heat exchanger, such as a free-floating head or U-tube heat exchanger.

[0027] In one optional embodiment, the flash tower 5 is a two-stage packed atmospheric pressure tower. The lower section is packed with DN50 Pall rings, and the filling height of the lower section is 3 to 5 times the inner diameter of the flash tower 5. The upper section is packed with 250Y structured packing, and the filling height of the upper section is 1 to 2 times the inner diameter of the flash tower 5. Exemplarily, the bottom of the flash tower 5 is equipped with an explosion-proof self-priming centrifugal pump with negative pressure suction.

[0028] In one optional implementation, compressor 6 is a Roots-type steam compressor equipped with an explosion-proof motor, and the steam extraction capacity is 1 to 1.5 times the maximum design evaporation capacity of flash tower 5.

[0029] In one optional embodiment, the stirred tank 7 is an atmospheric pressure reactor with a powder feeding hopper at the top for adding activated carbon powder. Exemplarily, the stirred tank 7 is a heated, stirred, enamel- or glass-lined atmospheric pressure reactor with a flame arrester and breather valve. The stirred tank 7 is used at atmospheric pressure and is equipped with an explosion-proof screw pump at the bottom.

[0030] In an optional implementation, filter 8 is a dual-set parallel-regenerated activated carbon filter bed, which achieves regeneration through program-controlled automatic backwashing, and each set of activated carbon filter beds is designed for at least 4 hours of filtration time. The dual-tank parallel design enables seamless switching between continuous sweet water feeding and batch settling for oil separation, avoiding production line downtime and improving processing efficiency.

[0031] In an optional embodiment, the glycerin tank 9, colloid tank 10, and water tank 11 are all small vertical tanks of the same specifications, and the effluent from the water tank 11 is recycled for oil hydrolysis. Exemplarily, the glycerin tank 9, colloid tank 10, and water tank 11 are all used under normal pressure, each equipped with a local and remote level gauge, automatic control of the discharge pump, and a flame arrester breather valve. Further, the glycerin tank 9 and colloid tank 10 are equipped with explosion-proof screw pumps, and the water tank 11 is equipped with an explosion-proof self-priming centrifugal pump.

[0032] It is understood that the oil hydrolysis sweet water purification device of this embodiment uses stainless steel (grade 316 and above) that meets pressure and corrosion standards for all main equipment, pipelines, instruments and pumps and valves, and is equipped with an external heat insulation structure to meet the needs of the use environment. The wind load, snow load and seismic load all meet the local meteorological and geological survey, and the electrical automation also meets the explosion-proof requirements and the communication protocol of the use site.

[0033] The working process of the oil hydrolysis sweet water purification device in this embodiment is as follows: Sweet water discharged from the fatty acid production line flows into either of the two oil separators 1. Once one separator 1 is full, the feed valve is closed, and the other separator 1 is fed. The temperature of a full separator 1 can be adjusted to 40℃~80℃ via a bottom heating coil, depending on the incoming material temperature, to reduce viscosity and accelerate stratification. The settling time is controlled to be at least 2 hours. After stratification, the upper layer is mixed oil, which is collected and discharged via a float. When water is observed through a pipe sight glass, the oil discharge is closed, and the discharged oil is temporarily stored in mixed oil tank 2. After discharge, the oil is pumped to subsequent pipelines for flash evaporation via a drain valve. Mixed oil tank 2 is equipped with an insulation layer and an electric heating system to prevent condensation.

[0034] After removing impurities from the sweet water, it is preheated in the primary heat exchanger 3 and then further heated to 110℃~120℃ in the secondary heat exchanger 4. It then enters the flash tower 5 for flash separation. The steam exits from the top of the tower, is drawn and pressurized by the compressor 6 to increase its temperature, and returns to the primary heat exchanger 3 to reheat the incoming material, thus recovering heat energy. The steam after the primary heat exchanger 3 is controlled by a steam trap, while the liquid phase is temporarily stored in the clear water tank 11. The secondary heat exchanger 4 can use surplus steam from the oil hydrolysis system or a temperature-controlled electric heater to supplement the energy required for flash separation. Initially, the flash tower 5 is cold and has not yet established flash balance. Therefore, it is recycled back to the primary heat exchanger 3 via the bottom circulation branch of the flash tower 5, mixed with the feed, and reheated for flash separation. Once overall balance is established and the concentration ratio reaches the target, it is discharged into the stirred tank 7.

[0035] Add powdered activated carbon to the powder feeding hopper at the top of the stirred tank 7. The powdered activated carbon should be added according to the experimentally determined addition ratio and stirred. After flash evaporation in the flash tower 5, the bottom liquid of the concentration tower will show a certain degree of polymerization and adhesion. Adding powdered activated carbon can improve the filtration performance of the filter 8 and simplify regeneration.

[0036] Filter 8 is a dual-bed activated carbon filter, filled with large-particle activated carbon for water treatment. The regeneration cycle is determined according to the filter bed pressure. A small amount of filtrate is used for backwashing to press out the colloid, which is then stored in colloid tank 10. The filtered liquid is then stored in glycerol tank 9.

[0037] After the sweet water separation is completed, the separated glycerol, colloid, clear water, and residual oil can be discharged from the unit as needed. The glycerol can be sold commercially, further refined by qualified units to produce food-grade glycerol, or used for other purposes. The colloid contains powdered activated carbon, has strong overall viscosity, and is flammable; it can be sold as a binder for biomass solid fuels to strengthen pellet fuel and increase its calorific value, and can be co-fired for power generation to reduce sulfur emissions from raw coal. The clear water has a slight oily odor but is already clear distilled water; it can be reused for oil hydrolysis to reduce external water resource consumption and emissions. The residual oil can be sold to qualified units to extract useful components such as vitamin E and lecithin, or sent to biodiesel plants for processing into environmentally friendly fuel to supplement petrochemical diesel energy. The entire process results in zero waste emissions, thus achieving the resource-based purification and recovery of all components of the sweet water.

[0038] It should be noted that the oil hydrolysis sweet water purification device in this embodiment should be started sequentially from front to back, with balanced operation. When shutting down, materials can remain in the storage tank, but the materials in the heat exchanger, tower, and reactor must be completely emptied, and the pipelines must be purged with steam. For long-term storage, especially in severe winter conditions, the pipelines, pumps, and valves must be dried with nitrogen to prevent residual water from freezing and cracking. Materials stored for extended periods may undergo microbial fermentation; these should be disposed of in the wastewater treatment system to prevent respiratory poisoning of personnel.

[0039] Understandably, the oil hydrolysis sweet water purification device of this embodiment allows for frequency conversion control of all pump components to maximize energy savings; and anti-vibration blocks are installed between moving parts and fixed areas (such as platform foundations or steel structures) to effectively avoid resonance damage and control noise levels. Furthermore, soft connections and expansion bends are used for buffering in areas of concentrated temperature stress, but this invention does not impose structural limitations on these aspects.

[0040] This utility model's oil hydrolysis sweet water purification device recovers impurities from sweet water that was originally directly discharged and difficult to biodegrade through thermal sedimentation, produces clean water by recovering steam heat energy through flash evaporation and mechanical compression, and produces glycerol and colloids through activated carbon filtration. It realizes the classification, purification, recycling and reuse of various resources, low-energy consumption and zero-waste production, and has a comprehensive improvement on the resources, environmental protection and economy of fatty acid production industry.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations are intended to cover non-exclusive inclusion, such that an article or device comprising a list of elements includes not only those elements but also other elements not expressly listed. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device comprising said element. Terms such as "connected" or "linked" are not limited to physical or mechanical connections but can include electrical connections, whether direct or indirect. The orientations or positional relationships indicated by terms such as "upper," "lower," "left," and "right" are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed or operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0042] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the protection scope of the present invention.

Claims

1. A device for purifying sweet water from oil hydrolysis, characterized in that, include: The system includes an oil distribution tank (1), a mixed oil tank (2), a primary heat exchanger (3), a secondary heat exchanger (4), a flash evaporator (5), a compressor (6), a mixing tank (7), a filter (8), a glycerin tank (9), a colloid tank (10), and a clean water tank (11); among which, The oil distribution tank (1) is configured as a double parallel structure. The lower left outlet of the oil distribution tank (1) is connected to the mixed oil tank (2), and the lower right outlet is connected to the first-stage heat exchanger (3), the second-stage heat exchanger (4), and the middle of the flash tower (5) via a pump. The top of the flash tower (5) is connected to the inlet of the compressor (6), and the outlet of the compressor (6) is connected to the heat source side of the first-stage heat exchanger (3) to form a steam heat energy recovery loop. The bottom outlet of the flash tower (5) is connected to the top of the stirred tank (7) via a pump. 7) The bottom outlet is connected to the inlet of the filter (8) via a pump; the filter (8) has two outlets, the upper outlet is connected to the glycerin tank (9), and the glycerin is discharged from the outlet of the glycerin tank (9), and the lower outlet is connected to the colloid tank (10), and the colloid is discharged from the outlet of the colloid tank (10); the flash tower (5) has a circulation branch after the bottom pump, which is connected to the feed port of the first-stage heat exchanger (3); the cold source side outlet of the first-stage heat exchanger (3) is connected to the clean water tank (11), and the clean water is discharged from the outlet of the clean water tank (11).

2. The oil hydrolysis sweet water purification device according to claim 1, characterized in that, The oil distribution tank (1) is a vertical tank with a heating coil at the bottom and a float oil discharge mechanism and radar level gauge at the top.

3. The oil hydrolysis sweet water purification device according to claim 2, characterized in that, The float-type oil discharge mechanism includes a float and a hose. The float is connected to the lower left outlet of the oil distribution tank (1) through the hose. The lower left outlet of the oil distribution tank (1) is an oil discharge port.

4. The oil hydrolysis sweet water purification device according to claim 1, characterized in that, The mixed oil tank (2) is a horizontal tank or a small vertical tank, located at a low position, with the highest liquid level being less than half the height of the oil distribution tank (1).

5. The oil hydrolysis sweet water purification device according to claim 1, characterized in that, The primary heat exchanger (3) is a shell-and-tube heat exchanger, and the secondary heat exchanger (4) is an electrically heated or shell-and-tube heat exchanger.

6. The oil hydrolysis sweet water purification device according to claim 1, characterized in that, The flash tower (5) is a two-stage packed atmospheric tower. The lower section packing is DN50 Pall rings, and the filling height of the lower section packing is 3 to 5 times the inner diameter of the flash tower (5). The upper section packing is 250Y structured packing, and the filling height of the upper section packing is 1 to 2 times the inner diameter of the flash tower (5).

7. The oil hydrolysis sweet water purification device according to claim 1, characterized in that, The compressor (6) is a Roots-type steam compressor, and the steam extraction capacity is 1 to 1.5 times the maximum design evaporation capacity of the flash tower (5).

8. The oil hydrolysis sweet water purification device according to claim 1, characterized in that, The stirred tank (7) is an atmospheric pressure reactor with a powder feeding hopper at the top for adding activated carbon powder.

9. The oil hydrolysis sweet water purification device according to claim 1, characterized in that, The filter (8) is a dual-group parallel interactive regeneration activated carbon filter bed, which achieves sewage discharge and regeneration through automatic backwashing.

10. The oil hydrolysis sweet water purification device according to claim 1, characterized in that, The glycerin tank (9), the colloid tank (10) and the water tank (11) are all small vertical tanks of the same specifications. The water output from the water tank (11) is recycled for oil hydrolysis.

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