System for recycling sodium acetate trihydrate

Abstract

The utility model provides a system for recycling sodium acetate trihydrate, which belongs to the technical field of sodium acetate preparation and comprises a dissolving component, an impurity removal component, an extraction component and a crystallization drying component which are sequentially connected. The dissolving assembly comprises a dissolving tank and an adjustable stirring assembly, and the adjustable stirring assembly can move up and down in the dissolving tank for stirring; the impurity removal assembly comprises a filtering tank, a flocculation tank and an ultrafiltration tank which are sequentially communicated, the filtering tank is communicated with the dissolving tank, the filtering tank is used for primary filtering, the flocculation tank is used for secondary filtering, and the ultrafiltration tank is used for tertiary filtering; the extraction assembly comprises a first tower body, a second tower body, an extract liquor reflux tank and a finished material tank, the crystallization drying assembly comprises a concentration crystallization tank and a drying tank, sodium acetate trihydrate in the byproduct sodium acetate is purified through the process method, 90%-95% of sodium acetate trihydrate in the byproduct sodium acetate can be extracted, and the sodium acetate trihydrate can be recycled. The purification efficiency of the sodium acetate trihydrate in the byproduct sodium acetate is improved, and the content of the sodium acetate trihydrate in impurities after the byproduct sodium acetate is purified is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of sodium acetate preparation, and particularly relates to a system for resourcefully recycling trisodium acetate trihydrate. Background Art

[0002] In the water treatment industry, trisodium acetate trihydrate (also known as sodium acetate trihydrate) is usually used as an effective carbon source in the biochemical treatment system for wastewater purification. Because it has a single molecular formula and molecular structure and is easy to be utilized by microorganisms, it is often used as a carbon source to provide nutrients for the growth and metabolism of microorganisms in the sewage biochemical treatment system, improving the biodegradability of the biochemical denitrification process of sewage. Trisodium acetate trihydrate can be prepared from by-product sodium acetate (also known as sodium acetate mother liquor), and the by-product sodium acetate is a waste generated in the factory production process, which not only contains various salt substances, organic substances, but also contains many heavy metal substances. It not only pollutes the environment but also causes waste of resources. Therefore, the by-product sodium acetate is recycled, and through processes such as impurity removal, centrifugation, extraction, etc., trisodium acetate trihydrate is prepared for use in the water treatment industry.

[0003] In the existing precise process of by-product sodium acetate, mainly through processes such as centrifugation, filtration, evaporation, crystallization, etc., the impurities in the by-product sodium acetate are removed, and the by-product sodium acetate is converted into white solid particles of trisodium acetate trihydrate as a sewage treatment carbon source agent.

[0004] However, in the existing precise process of by-product sodium acetate, only 60%-75% of trisodium acetate trihydrate in the by-product sodium acetate can be extracted, and the purification efficiency is low. The impurities after purification of the by-product sodium acetate still contain a relatively high content of trisodium acetate trihydrate. Summary of the Utility Model

[0005] Based on this, the utility model provides a system for resourcefully recycling trisodium acetate trihydrate to solve the technical problems existing in the prior art that in the existing precise process of by-product sodium acetate, only 60%-75% of trisodium acetate trihydrate in the by-product sodium acetate can be extracted, the purification efficiency is low, and the impurities after removing impurities from the by-product sodium acetate still contain a relatively high content of trisodium acetate trihydrate.

[0006] The technical solution of the utility model to solve the above technical problems is as follows:

[0007] A system for resourcefully recycling trisodium acetate trihydrate includes a dissolution component, an impurity removal component, an extraction component, and a crystallization and drying component connected in sequence;

[0008] The dissolution component includes a dissolution tank and an adjustable stirring component, and the adjustable stirring component can move up and down in the dissolution tank for stirring;

[0009] The impurity removal assembly includes a filtration tank, a flocculation tank and an ultrafiltration tank that are connected in sequence. The filtration tank is connected to the dissolution tank. The filtration tank is used for primary filtration, the flocculation tank is used for secondary filtration, and the ultrafiltration tank is used for tertiary filtration;

[0010] The extraction assembly includes a first tower body, a second tower body, an extraction liquid reflux tank and a finished product tank. The first tower body is connected to the ultrafiltration tank, the second tower body is connected to the first tower body. The extraction liquid reflux tank is used to reflux the extraction liquid of the first tower body and the second tower body. The finished product tank is connected to the second tower body;

[0011] The crystallization and drying assembly includes a concentrated crystallization tank and a drying tank. The concentrated crystallization tank is connected to the finished product tank and is used for concentrating and crystallizing sodium acetate trihydrate. The drying tank is connected to the concentrated crystallization tank and is also connected to the dissolution tank. The drying tank is used for drying sodium acetate trihydrate.

[0012] Preferably, the adjustable stirring assembly includes a connecting shaft, a stirring paddle, a crushing paddle, a driving motor and a lifting member. The connecting shaft is vertically suspended in the dissolution tank. The stirring paddle is installed on the connecting shaft and is located inside the dissolution tank. The crushing paddle is installed on the connecting shaft and is located below the stirring paddle. The driving motor is arranged at one end of the connecting shaft, and the lifting member is connected to the driving motor and drives the driving motor to move up and down in the vertical direction.

[0013] Preferably, the crushing paddle includes a mounting plate, a first crushing rod and a second crushing rod. The mounting plate is arranged at one end of the connecting shaft and is located on the side away from the driving motor. The first crushing rod is detachably arranged on the mounting plate, and the second crushing rod is detachably arranged on the mounting plate. A gap is reserved between the first crushing rod and the second crushing rod.

[0014] Preferably, a first coil pipe is arranged inside the dissolution tank. The first coil pipe is attached to the inner wall of the dissolution tank. The water inlet end and the water outlet end of the first coil pipe penetrate through the dissolution tank and extend to the outside of the dissolution tank.

[0015] Preferably, a plurality of filter plates are detachably arranged inside the filtration tank. Along the vertical direction, the plurality of filter plates are arranged in sequence, and a preset distance is arranged between adjacent filter plates; a rotating paddle is arranged inside the flocculation tank, and a flocculation box is arranged on the flocculation tank. The flocculation box is communicated with the flocculation tank; a PTFE flat membrane is arranged inside the ultrafiltration tank.

[0016] Preferably, the filter plate is provided with three layers, which are the first filter plate, the second filter plate and the third filter plate from top to bottom. A first filter screen is detachably arranged on the first filter plate, a second filter screen is detachably arranged on the second filter plate, and a third filter screen is detachably arranged on the third filter plate. The pore size of the first filter screen > the pore size of the second filter screen > the pore size of the third filter screen.

[0017] Preferably, a first sampling member is further arranged on the flocculation tank, and one end of the first sampling member extends into the flocculation tank; the first sampling member includes a first sampling pipe, a first extraction valve and a first sampling cup. One end of the first sampling pipe extends into the flocculation tank, the first extraction valve is arranged on the first sampling pipe, and the first sampling cup is arranged near the other end of the first sampling pipe.

[0018] Preferably, a first sieve plate is arranged in the first tower body. A first mother liquor pipe, a first extraction feed pipe, a first extraction liquid outlet pipe and a first mother liquor outlet pipe are arranged on the first tower body. The first extraction feed pipe is located below the first mother liquor pipe, the first extraction liquid outlet pipe is located at the top of the first tower body, and the first mother liquor outlet pipe is located at the bottom of the first tower body; a second sieve plate is arranged in the second tower body. A second mother liquor pipe, a second extraction feed pipe, a second extraction liquid outlet pipe and a second mother liquor outlet pipe are arranged on the second tower body. The second mother liquor pipe is communicated with the first mother liquor outlet pipe. The second extraction feed pipe is located below the second mother liquor pipe, the second extraction liquid outlet pipe is located at the top of the second tower body, and the second mother liquor outlet pipe is located at the bottom of the second tower body.

[0019] Preferably, a first extraction mixing box is arranged at one end of the first extraction feed pipe. A number of first extraction branch pipes are arranged on the first extraction mixing box, and a first flow limiting valve is arranged on the first extraction branch pipe; a second extraction mixing box is arranged at one end of the second extraction feed pipe. A number of second extraction branch pipes are arranged on the second extraction mixing box, and a second flow limiting valve is arranged on the second extraction branch pipe.

[0020] Preferably, a first heat exchange sleeve is arranged on the side wall of the first tower body, and a heating cavity is formed between the first heat exchange sleeve and the first tower body; a second heat exchange sleeve is arranged on the side wall of the second tower body, and a heating cavity is formed between the second heat exchange sleeve and the second tower body.

[0021] Compared with the prior art, the utility model has at least the following advantages:

[0022] By using this process method to purify sodium acetate trihydrate from by - product sodium acetate, 90% - 95% of sodium acetate trihydrate in the by - product sodium acetate can be extracted. Compared with traditional processes such as evaporation crystallization, only 60% - 75% of sodium acetate trihydrate in the by - product sodium acetate can be extracted, which improves the purification efficiency of sodium acetate trihydrate in the by - product sodium acetate and reduces the content of sodium acetate trihydrate in the impurities after the purification of the by - product sodium acetate. Brief Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the system for resource - recycling of sodium acetate trihydrate.

[0024] Figure 2 It is an isometric view of the dissolution component.

[0025] Figure 3 It is a front view of the dissolution component.

[0026] Figure 4 It is Figure 3 the sectional view taken along G - G in

[0027] Figure 5 It is Figure 4 a partial enlarged view.

[0028] Figure 6 It is a schematic diagram of the impurity - removing component.

[0029] Figure 7 It is a schematic diagram of the filtration tank.

[0030] Figure 8 It is a schematic diagram of the flocculation tank.

[0031] Figure 9 It is a schematic diagram of the extraction component.

[0032] Figure 10 It is a schematic diagram of the first tower body.

[0033] Figure 11 It is a schematic diagram of the second tower body.

[0034] In the figure: dissolution component 100, dissolution tank 110, first coiled pipe 111, second coiled pipe 112, adjustable stirring component 120, coupling shaft 121, stirring paddle 122, crushing paddle 123, mounting plate 1231, first crushing rod 1232, second crushing rod 1233, driving motor 124, lifting component 125, support platform 1251, driving cylinder 1252, bridge plate 1253, impurity removal component 200, filtration tank 210, filter plate 211, first filter plate 2111, second filter plate 2112, third filter plate 2113, sedimentation tank 212, reflux pipe 213, flocculation tank 220, rotating paddle 221, flocculation box 222, adsorption box 223, first sampling component 224, ultrafiltration tank 230, PTFE flat membrane 231, second sampling component 232, backwash pipe 233, extraction component 300, first tower body 310, first sieve plate 311, first mother liquor pipe 312, first extraction feed pipe 313, first extraction mixing box 3131, first extraction branch pipe 3132, first extraction liquid outlet pipe 314, first mother liquor outlet pipe 315, first heat exchange jacket 316, second tower body 320, second sieve plate 321, second mother liquor pipe 322, second extraction feed pipe 323, second extraction mixing box 3231, second extraction branch pipe 3232, second extraction liquid outlet pipe 324, second mother liquor outlet pipe 325, second heat exchange jacket 326, extraction liquid reflux tank 330, finished product tank 340, crystallization and drying component 400, concentrated crystallization tank 410, drying tank 420. Detailed implementation manners

[0035] It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other. The following will further describe the technical solutions of the present invention with reference to the drawings of the embodiments of the present invention. The present invention is not limited to the following specific implementation manners.

[0036] It should be understood that the same or similar reference numerals in the drawings of the embodiments correspond to the same or similar components. In the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "front", "rear", "left", "right", "top", "bottom", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations.

[0037] Please refer to Figures 1 to 11, A system for resource recovery of sodium acetate trihydrate, comprising a dissolution component 100, an impurity removal component 200, an extraction component 300 and a crystallization and drying component 400 connected in sequence;

[0038] Existing by-product sodium acetate is solid at room temperature, such as powdery, fragmented crystal, large crystal, and part of the by-product sodium acetate is in solution. During the dissolution process, the by-product sodium acetate and water are mixed to form a mixed solution, which is added to the dissolution tank 110 for dissolution. To accelerate the dissolution rate, the dissolution tank 110 is equipped with a stirring paddle 122. During the initial dissolution process, since the mixed solution contains undissolved large crystal by-product sodium acetate, during the stirring process of the stirring paddle 122, the stirring paddle 122 collides with the undissolved large crystal by-product sodium acetate, and during the long-term collision process, the stirring paddle 122 will be bent, and the connection of the stirring paddle 122 will become loose, resulting in a high damage rate of the stirring paddle 122. The dissolution component 100 includes a dissolution tank 110 and an adjustable stirring component 120, and the adjustable stirring component 120 can move up and down in the dissolution tank 110 for stirring; since the large crystal precipitates at the bottom of the dissolution tank 110, the adjustable stirring component 120 moves to the top position of the dissolution tank 110 and moves vertically downward for a preset distance to break the by-product sodium acetate crystals existing in the uppermost layer of the by-product sodium acetate mixed solution. After breaking for a preset time, it moves downward again. As the adjustable stirring component 120 gradually stirs, the large crystal by-product sodium acetate will be gradually dissolved, avoiding the direct collision between the adjustable stirring component 120 and the large crystal by-product sodium acetate and damaging the adjustable stirring component 120.

[0039] The impurity removal component 200 includes a filter tank 210, a flocculation tank 220 and an ultrafiltration tank 230 connected in sequence. The filter tank 210 is connected to the dissolution tank 110. The filter tank 210 is used for primary filtration, the flocculation tank 220 is used for secondary filtration, and the ultrafiltration tank 230 is used for tertiary filtration; through the primary filtration of large particle impurities by the filter tank 210, the secondary filtration of small particle impurities by the flocculation tank 220, and the tertiary filtration of micro particle impurities by the ultrafiltration tank 230, the content of impurities such as suspended particles, organic matters and metal ions in the by-product sodium acetate mixed solution (sodium acetate mother liquor) can be effectively reduced, and the impurity removal rate can be improved.

[0040] The extraction component 300 includes a first tower body 310, a second tower body 320, an extraction liquid reflux tank 330 and a finished product tank 340. The first tower body 310 is communicated with the ultrafiltration tank 230, the second tower body 320 is communicated with the second tower body 320. The extraction liquid reflux tank 330 is used for refluxing the extraction liquid of the first tower body 310 and the second tower body 320. The finished product tank 340 is communicated with the second tower body 320. By means of extraction, impurities in by-product sodium acetate are separated. Compared with traditional processes such as evaporation and crystallization for separating impurities in by-product sodium acetate, there is less sodium acetate trihydrate in the impurities of by-product sodium acetate, and the obtained sodium acetate trihydrate has higher purity.

[0041] The crystallization and drying component 400 includes a concentration and crystallization tank 410 and a drying tank 420. The concentration and crystallization tank 410 is communicated with the finished product tank 340 and is used for concentrating and crystallizing sodium acetate trihydrate. The drying tank 420 is communicated with the concentration and crystallization tank 410, and the drying tank 420 is also communicated with the dissolution tank 110. The drying tank 420 is used for drying sodium acetate trihydrate.

[0042] Achieved effects:

[0043] By purifying sodium acetate trihydrate in by-product sodium acetate through this process method, 90%-95% of sodium acetate trihydrate in by-product sodium acetate can be extracted. Compared with traditional processes such as evaporation and crystallization, only 60%-75% of sodium acetate trihydrate in by-product sodium acetate can be extracted, which improves the purification efficiency of sodium acetate trihydrate in by-product sodium acetate and reduces the content of sodium acetate trihydrate in the impurities after purification of by-product sodium acetate.

[0044] Further, referring to Figure 2 and Figure 5 , the adjustable stirring component 120 includes a coupling shaft 121, a stirring paddle 122, a crushing paddle 123, a driving motor 124 and a lifting member 125. The coupling shaft 121 is vertically suspended in the dissolution tank 110. The stirring paddle 122 is installed on the coupling shaft 121 and is located in the dissolution tank 110. The crushing paddle 123 is installed on the coupling shaft 121 and is located below the stirring paddle 122. The driving motor 124 is arranged at one end of the coupling shaft 121. The lifting member 125 is connected with the driving motor 124 and drives the driving motor 124 to move up and down in the vertical direction.

[0045] The specific working process of the adjustable stirring assembly 120 is as follows: Drive the lifting member 125 to move vertically upward, drive the stirring paddle 122 to move upward, and move to a position close to the top of the dissolution tank 110. Open the cover body, place the by-product sodium acetate solution or the by-product sodium acetate crystals in the dissolution tank 110, add an aqueous solution, and mix the two. Close the cover body to make the dissolution tank 110 in a closed state. Drive the lifting member 125 to move again and move vertically downward for a preset distance. First, make the crushing paddle 123 enter the mixed solution, start the motor to rotate, drive the crushing paddle 123 to rotate, and the crushing paddle 123 crushes the by-product sodium acetate crystals existing in the uppermost layer of the mixed solution. After crushing for a preset time, drive the lifting member 125 to move again and move vertically downward for a preset distance. The crushing paddle 123 crushes the by-product sodium acetate crystals existing in the middle layer of the mixed solution. After crushing for a preset time, drive the lifting member 125 to move again and move vertically downward for a preset distance. The crushing paddle 123 crushes the by-product sodium acetate crystals existing in the middle layer of the mixed solution. At the same time, the stirring paddle 122 is also completely immersed in the mixed solution for mixing and stirring. After crushing and stirring for a preset time, drive the lifting member 125 to move again and move vertically downward for a preset distance. The crushing paddle 123 crushes the by-product sodium acetate crystals existing in the lowermost layer of the mixed solution. At the same time, the stirring paddle 122 stirs the mixed solution until all are dissolved.

[0046] Achieved effects: By adding the crushing paddle 123 and the lifting member 125, the lifting member 125 drives the crushing paddle 123 and the stirring paddle 122 to move up and down in the vertical direction, so that the crushing paddle 123 first crushes the large crystal by-product sodium acetate into small crystal by-product sodium acetate, accelerates the dissolution of the crystal by-product sodium acetate, improves the dissolution rate. At the same time, it avoids the collision between the stirring paddle 122 and the large crystal by-product sodium acetate, prevents the stirring paddle 122 from being damaged, and prolongs the service life of the stirring paddle 122.

[0047] Furthermore, refer to Figure 4 and Figure 5, the crushing paddle 123 includes a mounting plate 1231, a first crushing rod 1232 and a second crushing rod 1233. The mounting plate 1231 is arranged at one end of the connecting shaft 121 and is located on the side away from the driving motor 124. The first crushing rod 1232 is detachably arranged on the mounting plate 1231, and the second crushing rod 1233 is detachably arranged on the mounting plate 1231. A plurality of the first crushing rods 1232 and / or the second crushing rods 1233 can be arranged on the mounting plate 1231. The first crushing rod 1232 and the second crushing rod 1233 are made of a material with high hardness, such as steel bars. A gap is reserved between the first crushing rod 1232 and the second crushing rod 1233. By providing the first crushing rod 1232 and the second crushing rod 1233, when the first crushing rod 1232 and the second crushing rod 1233 rotate and collide with the large crystal by-product sodium acetate, the large crystal by-product sodium acetate can be broken, thereby improving the crushing efficiency of the large crystal by-product sodium acetate. At the same time, the reserved gap enables the broken small crystal by-product sodium acetate to pass through the gap, preventing the by-product sodium acetate crystal block from getting stuck between the first crushing rod 1232 and the second crushing rod 1233 and affecting the crushing efficiency of the by-product sodium acetate crystals.

[0048] Furthermore, the first crushing rod 1232 includes a first straight rod and a first curved rod. One end of the first straight rod is connected to the mounting plate 1231, and the first curved rod is connected to the other end of the first straight rod. The bending direction of the first curved rod is the same as the rotation direction of the connecting shaft 121. When the first straight rod and / or the first curved rod collide with the large crystal by-product sodium acetate and do not break the large crystal by-product sodium acetate, under the centrifugal rotation state of the mixed liquid, the large crystal by-product sodium acetate will rotate towards the side of the first curved rod and rotate to the rear, and will be continuously collided by the first straight rod and the first curved rod that rotate again, so as to break the large crystal by-product sodium acetate, and avoid the first crushing rod 1232 continuously driving the large crystal by-product sodium acetate to rotate.

[0049] For further description, the lifting member 125 includes a support platform 1251, a driving cylinder 1252 and a bridge plate 1253. The support platform 1251 is installed on one side of the dissolution tank 110. The driving cylinder 1252 is arranged on the support platform 1251. One end of the bridge plate 1253 is connected to the driving cylinder 1252, and the other end of the bridge plate 1253 is connected to the driving motor 124. The support platform 1251 is used to lift the driving cylinder 1252. The staff controls the driving cylinder 1252 to move up and down in the vertical direction. The bridge plate 1253 has a bridging function and connects the driving cylinder 1252 and the coupling shaft 121 at the same time. That is, when the driving cylinder 1252 rises, it drives the coupling shaft 121 to rise, and when the driving cylinder 1252 descends, it drives the coupling shaft 121 to descend.

[0050] In a possible embodiment, referring to Figure 4 and Figure 5 , in order to accelerate the dissolution of by-product sodium acetate, a first coil pipe 111 is arranged in the dissolution tank 110. The first coil pipe 111 is attached to the inner wall of the dissolution tank 110. The water inlet end and the water outlet end of the first coil pipe 111 penetrate through the dissolution tank 110 and extend to the outside of the dissolution tank 110. The water inlet end of the first coil pipe 111 is located at the bottom of the dissolution tank 110, and the water inlet end of the first coil pipe 111 is located at the top of the dissolution tank 110. Hot water is introduced into the water inlet end of the first coil pipe 111 and enters the first coil pipe 111. High temperature can accelerate the mutual dissolution of by-product sodium acetate and water. For example, when the water temperature is 25 °C, about 36 g of sodium acetate can be dissolved in each kilogram of water, and when the water temperature is 100 °C, about 100 g of sodium acetate can be dissolved in each kilogram of water. Therefore, heating the by-product sodium acetate mixed solution can effectively improve the dissolution rate. At the same time, attaching the first coil pipe 111 to the inner wall of the dissolution tank 110 can improve the heating speed of the by-product sodium acetate mixed solution.

[0051] Furthermore, a first valve is arranged on the water inlet end of the first coil pipe 111. The first valve can control the flow rate of the hot water in the first coil pipe 111.

[0052] Furthermore, referring to Figure 4 and Figure 5, in order to further accelerate the dissolution rate of by-product sodium acetate in the dissolution tank 110 and improve the process efficiency, a second coiled pipe 112 is further arranged in the dissolution tank 110. The second coiled pipe 112 is attached to the inner wall of the dissolution tank 110. The second coiled pipe 112 is arranged in a staggered manner with the first coiled pipe 111. The water inlet end and the water outlet end of the second coiled pipe 112 penetrate through the dissolution tank 110 and extend to the outside of the dissolution tank 110. After the first coiled pipe 111 is turned on for a preset time, the second coiled pipe 112 is turned on. The first coiled pipe 111 and the second coiled pipe 112 are used to heat the by-product sodium acetate mixed solution at the same time, so that the by-product sodium acetate mixed solution is heated to a preset temperature and the preset temperature is maintained. When the preset temperature is maintained, the second coiled pipe 112 is closed, and the first coiled pipe 111 maintains the preset temperature. When by-product sodium acetate is added into the dissolution tank 110 again, the second coiled pipe 112 is turned on for rapid heating and dissolution.

[0053] Furthermore, a second valve is arranged on the water inlet end of the second coiled pipe 112. The second valve can control the hot water flow rate in the second coiled pipe 112.

[0054] In a possible embodiment, refer to Figure 6 and Figure 8 , a plurality of filter plates are detachably arranged in the filter tank 210. Along the vertical direction, the plurality of filter plates are arranged in sequence, and a preset distance is arranged between adjacent filter plates; a rotating paddle 221 is arranged in the flocculation tank 220, and a flocculation box 222 is arranged on the flocculation tank 220. The flocculation box 222 is communicated with the flocculation tank 220; a PTFE flat membrane 231 is arranged in the ultrafiltration tank 230.

[0055] The specific working process of the impurity removal component 200 is as follows: After the dissolution component 100 is dissolved and the by-product sodium acetate mixed solution is discharged, it enters the filter tank 210 from the liquid inlet of the filter tank 210 and is discharged onto the filter plate. After being filtered through several layers of the filter plates, the large particle impurities in the by-product sodium acetate mixed solution remain on the filter plate. The filtered by-product sodium acetate mixed solution (the first filtered solution) flows to the bottom of the filter tank 210. The first filtered solution in the filter tank 210 gradually increases and is discharged from the liquid outlet of the filter tank 210 and is pumped into the flocculation tank 220 by a pump. When there is a certain amount of by-product sodium acetate mixed solution (the first filtered solution) in the flocculation tank 220, a flocculant is added to the flocculation tank 220 through the flocculation box 222. The motor is started, and the rotating paddle 221 is driven by the motor to rotate, so that the flocculant is evenly distributed in the by-product sodium acetate mixed solution (the first filtered solution). The flocculant can quickly agglomerate the suspended substances in the by-product sodium acetate mixed solution (the first filtered solution) and precipitate to the bottom of the flocculation tank 220. The upper layer is the by-product sodium acetate mixed solution (the second filtered solution). The by-product sodium acetate mixed solution (the second filtered solution) in the upper layer of the flocculation tank 220 is extracted by a pump and discharged into the ultrafiltration tank 230 through the liquid inlet of the ultrafiltration tank 230. The by-product sodium acetate mixed solution (the second filtered solution) is filtered by the PTFE flat membrane 231 in the ultrafiltration tank 230. After filtration, a by-product sodium acetate mixed solution (the third filtered solution) is formed and accumulates at the bottom of the ultrafiltration tank 230. The by-product sodium acetate mixed solution (the third filtered solution) is discharged from the liquid discharge port of the ultrafiltration tank 230 for the next process step.

[0056] Achieved effects: By allowing the by-product sodium acetate mixed solution to enter the filter tank 210, the flocculation tank 220, and the ultrafiltration tank 230 in sequence, the multi-layer filter plates in the filter tank 210 can filter large particle impurities, achieving primary filtration of large particle impurities. At the same time, undissolved sodium acetate crystals will remain on the filter plate. As the by-product sodium acetate mixed solution gradually flushes the filter plate, part of the sodium acetate will dissolve. While removing impurities, the dissolution of sodium acetate crystals is carried out. For part of the remaining sodium acetate crystals and impurities, the filter plate is disassembled, and the impurities and the remaining sodium acetate crystals are backfilled into the dissolution device for secondary dissolution;

[0057] Adding a flocculant in the flocculation tank 220 can quickly agglomerate the suspended substances in the by-product sodium acetate mixed solution (the first filtered solution), achieving secondary filtration of small particle impurities;

[0058] The PTFE flat membrane 231 in the ultrafiltration tank 230 filters the fine particle impurities in the by-product sodium acetate mixed solution (the second filtered solution), achieving tertiary filtration of fine particle impurities;

[0059] The large particle impurities are filtered at the first stage by the filtration tank 210, the small particle impurities are filtered at the second stage by the flocculation tank 220, and the micro particle impurities are filtered at the third stage by the ultrafiltration tank 230, which can effectively reduce the contents of impurities such as suspended particles, organic matters and metal ions in the by-product sodium acetate mixed solution (sodium acetate mother liquor), improve the impurity removal rate, and at the same time, can effectively avoid the fouling and blockage of the ultrafiltration (PTFE) membrane.

[0060] As a further description, refer to Figure 7 , a settling tank 212 is arranged at the bottom of the filtration tank 210, and a reflux pipe 213 is further arranged on the filtration tank 210. One end of the reflux pipe 213 is communicated with the settling tank 212, and the other end of the reflux pipe 213 extends to the top of the filtration tank 210. Since the by-product sodium acetate mixed solution (the first filtration solution) contains small particle impurities, they will settle at the bottom of the filtration tank 210 and settle in the settling tank 212. Set a preset time, open the reflux pipe 213, pump the by-product sodium acetate mixed solution (the first filtration solution) in the settling tank 212 through a pump body, and reflux it to the liquid inlet of the filtration tank 210 at the top of the filtration tank 210 for impurity removal again, so as to prevent more impurities from precipitating at the bottom of the filtration tank 210.

[0061] Further, refer to Figure 7 , the filter plate is provided with three layers, which are the first filter plate 2111, the second filter plate 2112 and the third filter plate 2113 from top to bottom. A first filter screen is detachably arranged on the first filter plate 2111, a second filter screen is detachably arranged on the second filter plate 2112, and a third filter screen is detachably arranged on the third filter plate 2113. The pore diameter of the first filter screen > the pore diameter of the second filter screen > the pore diameter of the third filter screen. To improve the filtration efficiency, and at the same time, to avoid too many impurities being filtered on the topmost filter plate while there are no impurities on the lower filter plates. By setting the first filter screen, the second filter screen and the third filter screen, with the pore diameter of the first filter screen > the pore diameter of the second filter screen > the pore diameter of the third filter screen, since the pore diameter of the first filter screen is the largest, impurities with larger diameters will be filtered, the second filter screen filters impurities with slightly smaller diameters, and the third filter screen filters impurities with even smaller diameters. The filtered impurities will be more evenly distributed on the first filter screen, the second filter screen and the third filter screen, avoiding too many impurities being filtered on the first filter screen and blocking the first filter screen. For the filtered impurities, regularly disassemble the first filter plate 2111, the second filter plate 2112 and the third filter plate 2113, and clean the impurities on the first filter screen, the second filter screen and the third filter screen. Moreover, when it is found that the first filter screen, the second filter screen and the third filter screen are damaged, replace the first filter screen or the second filter screen or the third filter screen.

[0062] Specifically, an opening is provided on the filter tank 210, and the opening is sealed by a sealing plate. A clamping groove is provided in the filter tank 210. The first filter plate 2111, the second filter plate 2112, and the third filter plate 2113 are clamped in the clamping groove. When disassembling the filter plate, open the sealing plate and take out the filter plate from the opening for cleaning.

[0063] Preferably, referring to Figure 8 , an adsorption box 223 is further provided on the flocculation tank 220. The adsorption box 223 is filled with an adsorbent, and the adsorption box 223 is communicated with the flocculation tank 220. In order to accelerate the impurity filtration rate of the by-product sodium acetate mixed solution (the first filtered solution) entering the flocculation tank 220, while the impurities are coagulated by the flocculant in the flocculation box 222, open the adsorption box 223, add the adsorbent into the flocculation tank 220, and stir by the rotating paddle 221 to coagulate the impurities in the by-product sodium acetate mixed solution (the first filtered solution). By adding the adsorbent, the impurity coagulation efficiency in the by-product sodium acetate mixed solution (the first filtered solution) can be greatly improved, and the impurities in the by-product sodium acetate mixed solution (the first filtered solution) can be reduced.

[0064] Furthermore, in order to detect the purity of the by-product sodium acetate mixed solution (the second filtered solution) and prevent the excessive impurities in the by-product sodium acetate mixed solution (the second filtered solution) from clogging the PTFE flat membrane 231, a first sampling member 224 is further provided on the flocculation tank 220. One end of the first sampling member 224 extends into the flocculation tank 220, and the first sampling member 224 is arranged at the top of the flocculation tank 220. After adding the flocculant and the adsorbent to the by-product sodium acetate mixed solution (the first filtered solution), stir for a preset time and then let it stand. The impurities in the by-product sodium acetate mixed solution (the first filtered solution) coagulate and precipitate at the bottom of the flocculation tank 220, and the upper layer is the by-product sodium acetate mixed solution (the second filtered solution) after impurity removal. The first sampling member 224 regularly extracts the by-product sodium acetate mixed solution (the second filtered solution) and detects it. If the purity of the by-product sodium acetate mixed solution (the second filtered solution) meets the standard, the by-product sodium acetate mixed solution (the second filtered solution) is pumped by a pump body and enters the ultrafiltration tank 230 through the liquid inlet of the ultrafiltration tank 230. If the purity of the by-product sodium acetate mixed solution (the second filtered solution) does not meet the standard, the flocculant and the adsorbent are added into the flocculation tank 220 again.

[0065] Specifically, a waste discharge pipe is provided at the bottom of the flocculation tank 220. Open the waste discharge pipe to discharge the impurities coagulated at the bottom of the flocculation tank 220.

[0066] Specifically, the first sampling member 224 includes a first sampling tube, a first extraction valve, and a first sampling cup. One end of the first sampling tube extends into the flocculation tank 220. The first extraction valve is disposed on the first sampling tube, and the first sampling cup is disposed near the other end of the first sampling tube. When it is necessary to detect the purity of the by-product sodium acetate mixed solution (the second filtered solution), the first extraction valve is opened, and the by-product sodium acetate mixed solution (the second filtered solution) in the flocculation tank 220 is extracted through the first sampling tube and discharged into the first sampling cup, and then sent to the testing room for testing.

[0067] Further, in order to detect the purity of the by-product sodium acetate mixed solution (the third filtered solution) and improve the purity of the sodium acetate trihydrate produced in the subsequent process, a second sampling member 232 is further disposed on the ultrafiltration tank 230, and one end of the second sampling member 232 extends into the ultrafiltration tank 230. The second sampling member 232 has the same structure as the first sampling member 224. The by-product sodium acetate mixed solution (the second filtered solution) enters the PTFE flat membrane 231 in the ultrafiltration tank 230. After being filtered by the PTFE flat membrane 231, the filtered by-product sodium acetate mixed solution (the third filtered solution) converges at the bottom of the ultrafiltration tank 230. The second sampling member 232 periodically extracts the by-product sodium acetate mixed solution (the third filtered solution) and performs detection. If the purity of the by-product sodium acetate mixed solution (the third filtered solution) meets the standard, the by-product sodium acetate mixed solution (the third filtered solution) is pumped through a pump body to enter the next process step. If the purity of the by-product sodium acetate mixed solution (the third filtered solution) does not meet the standard, it is refluxed for filtration again, or it is detected whether the PTFE flat membrane 231 is damaged.

[0068] Specifically, the second sampling member 232 includes a second sampling tube, a second extraction valve, and a second sampling cup. One end of the second sampling tube extends into the ultrafiltration tank 230. The second extraction valve is disposed on the second sampling tube, and the second sampling cup is disposed near the other end of the second sampling tube. When it is necessary to detect the purity of the by-product sodium acetate mixed solution (the third filtered solution), the second extraction valve is opened, and the by-product sodium acetate mixed solution (the third filtered solution) in the ultrafiltration tank 230 is extracted through the second sampling tube and discharged into the second sampling cup, and then sent to the testing room for testing.

[0069] Furthermore, when more impurities are attached to the PTFE flat membrane 231, the filtering effect of the PTFE flat membrane 231 is reduced. Therefore, a backwash pipe 233 is also provided on the ultrafiltration tank 230. The backwash pipe 233 is arranged on the side away from the liquid inlet of the ultrafiltration tank 230. The backwash pipe 233 is opened, and the connecting pipe between the PTFE flat membrane 231 in the ultrafiltration tank 230 and the flocculation tank 220 is disconnected, so that the PTFE flat membrane 231 in the ultrafiltration tank 230 is in internal circulation, and clean water enters the PTFE flat membrane 231. Since the flow direction of the clean water is opposite to the flow direction of the by-product sodium acetate mixed solution (the third filtered solution), under the action of backwashing, the impurities on the PTFE flat membrane 231 will be flushed to the bottom of the ultrafiltration tank 230.

[0070] The ultrafiltration tank 230 is also provided with a three-way pipe, the first pipe of the three-way pipe is connected to the bottom of the ultrafiltration tank 230, the second pipe of the three-way pipe is provided with a second valve, and the third pipe of the three-way pipe is provided with a third valve. When the by-product sodium acetate mixed solution (third filtered solution) is retained in the ultrafiltration tank 230, the second valve is opened, and the by-product sodium acetate mixed solution (third filtered solution) is extracted through the pump body; when the impurity solution is retained in the ultrafiltration tank 230 after backwashing, the third valve is opened, and the second valve is closed to remove the impurity solution retained in the ultrafiltration tank 230.

[0071] For further information, see Figure 9 The first tower body 310 is provided with a first sieve plate 311, and the first tower body 310 is provided with a first mother liquor pipe 312, a first extraction liquid inlet pipe 313, a first extraction liquid outlet pipe 314 and a first mother liquor liquid outlet pipe 315, wherein the first extraction liquid inlet pipe 313 is located below the first mother liquor pipe 312, the first extraction liquid outlet pipe 314 is located at the top of the first tower body 310, and the first mother liquor liquid outlet pipe 315 is located at the bottom of the first tower body 310; the second tower body 320 is provided with There is a second sieve plate 321, and the second tower body 320 is provided with a second mother liquor pipe 322, a second extraction liquid inlet pipe 323, a second extraction liquid outlet pipe 324 and a second mother liquor liquid outlet pipe 325, the second mother liquor pipe 322 is connected to the first mother liquor liquid outlet pipe 315, the second extraction liquid inlet pipe 323 is located below the second mother liquor pipe 322, the second extraction liquid outlet pipe 324 is located at the top of the second tower body 320, and the second mother liquor liquid outlet pipe 325 is located at the bottom of the second tower body 320.

[0072] The specific working process of the extraction component 300 is as follows: The by-product sodium acetate mixed solution is introduced into the first tower body 310 through the first mother liquor pipe 312, and the extractant (used to extract and separate impurities in the by-product sodium acetate mixed solution) is introduced into the first tower body 310 through the first extraction feed pipe 313. The by-product sodium acetate mixed solution and the extractant are mixed with each other. Since the density of the extractant is less than that of the by-product sodium acetate mixed solution, and the first extraction feed pipe 313 is located below the first mother liquor pipe 312, the extractant and the by-product sodium acetate mixed solution enter the first tower body 310 at the same time. When the extractant enters the first tower body 310, it will first fall to the bottom of the first tower body 310. As the by-product sodium acetate mixed solution enters, the by-product sodium acetate mixed solution with a heavier mass fraction will precipitate to the bottom of the first tower body 310, and the extractant will be exchanged to the top of the first tower body 310. Therefore, the extractant will make countercurrent contact with the by-product sodium acetate mixed solution in the first tower body 310. The organic matter in the by-product sodium acetate mixed solution and the extractant are dissolved in the extractant through the principle of like dissolves like. The primary trisodium acetate solution produced after extraction is insoluble in the extractant. The primary trisodium acetate solution produced after extraction sinks to the bottom of the first tower body 310, and the extractant mixed with impurities formed again after extraction floats above the primary trisodium acetate solution. The primary trisodium acetate solution and the extractant are clearly stratified. Generally, after extraction, a stratified solution is formed. The bottom layer is the primary trisodium acetate solution layer, and the upper two layers are the extractant layers. As the by-product sodium acetate mixed solution and the extractant are continuously added until the entire first tower body 310 is filled, the lighter extractant layer at the top of the tower will flow out from the upper first extraction liquid outlet pipe 314 and enter the extraction liquid reflux tank 330, and the primary trisodium acetate solution at the bottom of the tower will flow out from the second mother liquor outlet pipe 325.

[0073] Through pumping by the pump body, the primary trisodium acetate solution enters the second tower body 320 through the second mother liquor pipe 322, and a new unextracted extractant is added and enters the second tower body 320 through the second extraction feed pipe 323. The primary trisodium acetate solution undergoes secondary extraction in the second tower body 320 and forms a secondary trisodium acetate solution. The extraction effect is the same as the extraction method of the first tower body 310, and through extraction, a trisodium acetate solution with better purity and fewer impurities can be obtained. The extractant flows out from the second extraction liquid outlet pipe 324 at the top of the tower, and the trisodium acetate solution flows out from the second mother liquor outlet pipe 325 and enters the material forming tank 340.

[0074] The extraction solution in the extraction liquid reflux tank 330 is rectified to obtain each extractant again for use in subsequent extraction. The trisodium acetate solution in the material forming tank 340 undergoes processes such as concentration and crystallization to obtain trisodium acetate.

[0075] Achieved effect: By means of extraction, impurities in by-product sodium acetate are separated. Compared with traditional processes such as evaporation and crystallization for separating impurities in by-product sodium acetate, there is less sodium acetate trihydrate in the impurities of by-product sodium acetate, and the obtained sodium acetate trihydrate has higher purity, greatly improving the purification efficiency of purifying sodium acetate trihydrate from by-product sodium acetate.

[0076] Furthermore, referring to Figure 10 , one end of the first extraction inlet pipe 313 is provided with a first extraction mixing tank 3131. A number of first extraction branch pipes 3132 are arranged on the first extraction mixing tank 3131, and a first flow limiting valve is arranged on the first extraction branch pipe 3132. In the first method, if a single extraction agent is used, one of the first extraction branch pipes 3132 is used to introduce the extraction agent. The extraction agent enters the first extraction mixing tank 3131, and the single type of extraction agent is sent into the first extraction inlet pipe 313 through a pump body and flows to the first tower body 310. In the second method, if it is necessary to improve the extraction efficiency of by-product sodium acetate, two or more extraction agents are mixed and added into the first tower body 310. Therefore, by introducing different types of extraction agents from different first extraction branch pipes 3132, they are mixed in the first extraction mixing tank 3131, and the mixed extraction liquid is sent into the first extraction inlet pipe 313 through a pump body and flows to the first tower body 310, thereby improving the extraction efficiency and the removal effect of impurities in by-product sodium acetate.

[0077] Specifically, the first flow limiting valve is used to control the flow rate of the extraction agent in the first extraction branch pipe 3132, and when the extraction agent in the first extraction branch pipe 3132 reaches the standard amount, stop adding the extraction agent into the first extraction mixing tank 3131.

[0078] Even further, referring to Figure 11 , one end of the second extraction inlet pipe 323 is provided with a second extraction mixing tank 3231. A number of second extraction branch pipes 3232 are arranged on the second extraction mixing tank 3231, and a second flow limiting valve is arranged on the second extraction branch pipe 3232. Uncontaminated extraction agent (i.e., unused extraction agent) is introduced into the second extraction branch pipe 3232. The extraction agent added by the second extraction branch pipe 3232 can be the same as the extraction agent added by the first extraction branch pipe 3132 for secondary extraction to improve the impurity removal efficiency of by-product sodium acetate.

[0079] Specifically, the second flow limiting valve is used to control the flow rate of the extraction agent in the second extraction branch pipe 3232, and when the extraction agent in the second extraction branch pipe 3232 reaches the standard amount, stop adding the extraction agent into the second extraction mixing tank 3231.

[0080] Preferably, to improve the extraction efficiency, the extraction efficiency of by-product sodium acetate is better in the heated state, and the impurity removal efficiency of by-product sodium acetate can be further improved. A first heat exchange jacket 316 is provided on the side wall of the first tower body 310. A heating cavity is formed between the first heat exchange jacket 316 and the first tower body 310. A hot solution inlet is provided at the bottom of the first heat exchange jacket 316 near the position of the tower kettle, and a hot solution outlet is provided at the top of the first heat exchange jacket 316 near the position of the tower top. Hot solution, such as water with a higher temperature, is introduced into the hot solution inlet. The hot solution enters the heating cavity and fills the heating cavity, and then flows out from the hot solution outlet. A hot solution circulation can be formed by a pump body, and the hot solution is continuously heated to increase the temperature of the by-product sodium acetate in the first tower body 310, thereby improving the extraction efficiency and purifying more sodium acetate trihydrate.

[0081] Further preferably, a first heat insulation jacket is sleeved on the first heat exchange jacket 316, and heat insulation cotton is filled in the first heat insulation jacket. By providing the first heat insulation jacket and wrapping the outer surface of the first heat exchange jacket 316 with the heat insulation cotton, the heat loss of the hot solution in the first heat exchange jacket 316 can be prevented.

[0082] Even more preferably, a second heat exchange jacket 326 is provided on the side wall of the second tower body 320. A heating cavity is formed between the second heat exchange jacket 326 and the second tower body 320. The effect of the second heat exchange jacket 326 is the same as that of the first heat exchange jacket 316, which is to improve the extraction efficiency and purify more sodium acetate trihydrate.

[0083] Even more preferably, a second heat insulation jacket is sleeved on the second heat exchange jacket 326, and heat insulation cotton is filled in the second heat insulation jacket. The effect of the second heat exchange jacket 326 is the same as that of the first heat insulation jacket, which is to prevent the heat loss of the hot solution in the second heat exchange jacket 326.

[0084] Specifically, a first pressure detection member is provided on the top of the first tower body 310, and a second pressure detection member is provided on the top of the second tower body 320. To prevent the pressure in the first tower body 310 from being too high and to detect it in time to improve safety.

[0085] Specifically, a first manhole is opened on the side wall of the first tower body 310, and a second manhole is opened on the side wall of the second tower body 320.

[0086] Specifically, a number of first observation ports are opened on the side wall of the first tower body 310, and a number of second observation ports are opened on the side wall of the second tower body 320.

[0087] Preferably, see Figure 1, the concentration crystallization tank 410 is an existing concentration crystallization device, which is used to remove the moisture in the sodium acetate trihydrate solution and crystallize the crystalline sodium acetate trihydrate. The drying tank 420 is used to dry the crystallized sodium acetate trihydrate and prepare the formed sodium acetate trihydrate, while the residue or the contaminated sodium acetate trihydrate crystals flow back into the dissolution tank 110 and are dissolved again.

[0088] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A system for recycling sodium acetate trihydrate, characterized in that: It includes a dissolving component, an impurity removal component, an extraction component and a crystallization drying component which are connected in sequence; The dissolving component includes a dissolving tank and an adjustable stirring component, and the adjustable stirring component can move up and down in the dissolving tank to stir; The impurity removal component comprises a filter tank, a flocculation tank and an ultrafiltration tank which are connected in sequence, the filter tank is connected with the dissolution tank, the filter tank is used for primary filtration, the flocculation tank is used for secondary filtration, and the ultrafiltration tank is used for tertiary filtration; The extraction assembly comprises a first tower body, a second tower body, an extract reflux tank and a material forming tank, the first tower body is connected to the ultrafiltration tank, the second tower body is connected to the first tower body, the extract reflux tank is used to reflux the extracts of the first tower body and the second tower body, and the material forming tank is connected to the second tower body; The crystallization and drying component includes a concentration crystallization tank and a drying tank. The concentration crystallization tank is connected to the material forming tank and is used to concentrate and crystallize sodium acetate trihydrate. The drying tank is connected to the concentration crystallization tank and the drying tank is connected to the dissolving tank. The drying tank is used to dry sodium acetate trihydrate.

2. The system for recycling sodium acetate trihydrate as claimed in claim 1, characterized in that: The adjustable stirring assembly includes a connecting shaft, a stirring paddle, a crushing paddle, a driving motor and a lifting member. The connecting shaft is vertically suspended in the dissolution tank. The stirring paddle is installed on the connecting shaft and is located in the dissolution tank. The crushing paddle is installed on the connecting shaft and is located below the stirring paddle. The driving motor is arranged at one end of the connecting shaft. The lifting member is connected to the driving motor and drives the driving motor to move up and down in the vertical direction.

3. The system for recycling sodium acetate trihydrate as claimed in claim 2, characterized in that: The breaker paddle includes a mounting plate, a first breaker bar and a second breaker bar. The mounting plate is arranged at one end of the connecting shaft and is located on a side away from the driving motor. The first breaker bar is detachably arranged on the mounting plate, and the second breaker bar is detachably arranged on the mounting plate. A gap is reserved between the first breaker bar and the second breaker bar.

4. The system for recycling sodium acetate trihydrate as claimed in claim 2, characterized in that: A first coil is arranged in the dissolving tank. The first coil is attached to the inner wall of the dissolving tank. The water inlet and the water outlet of the first coil penetrate the dissolving tank and extend to the outside of the dissolving tank.

5. The system for recycling sodium acetate trihydrate as claimed in claim 1, characterized in that: Several layers of filter plates are detachably arranged in the filter tank. In the vertical direction, the filter plates are arranged in sequence, and a preset distance is set between adjacent filter plates. A rotating paddle is arranged in the flocculation tank, and a flocculation box is arranged on the flocculation tank, and the flocculation box is connected to the flocculation tank. A PTFE flat membrane is arranged in the ultrafiltration tank.

6. The system for recycling sodium acetate trihydrate as claimed in claim 5, characterized in that: The filter plate is provided with three layers, which are respectively the first filter plate, the second filter plate and the third filter plate from top to bottom. The first filter plate is detachably provided with a first filter screen, the second filter plate is detachably provided with a second filter screen, and the third filter plate is detachably provided with a third filter screen. The aperture size of the first filter screen is greater than the aperture size of the second filter screen and greater than the aperture size of the third filter screen.

7. The system for recycling sodium acetate trihydrate as claimed in claim 5, characterized in that: A first sampling piece is also provided on the flocculation tank, and one end of the first sampling piece extends into the flocculation tank; the first sampling piece includes a first sampling tube, a first extraction valve and a first sampling cup, one end of the first sampling tube extends into the flocculation tank, the first extraction valve is arranged on the first sampling tube, and the first sampling cup is arranged near the other end of the first sampling tube.

8. The system for recycling sodium acetate trihydrate as claimed in claim 1, characterized in that: A first sieve plate is arranged in the first tower body, and a first mother liquor pipe, a first mixed extraction pipe, a first extraction liquid outlet pipe and a first mother liquor outlet pipe are arranged on the first tower body, the first mixed extraction pipe is located below the first mother liquor pipe, the first extraction liquid outlet pipe is located at the top of the first tower body, and the first mother liquor outlet pipe is located at the bottom of the first tower body; a second sieve plate is arranged in the second tower body, and a second mother liquor pipe, a second mixed extraction pipe, a second extraction liquid outlet pipe and a second mother liquor outlet pipe are arranged on the second tower body, the second mother liquor pipe is connected with the first mother liquor outlet pipe, the second mixed extraction pipe is located below the second mother liquor pipe, the second extraction liquid outlet pipe is located at the top of the second tower body, and the second mother liquor outlet pipe is located at the bottom of the second tower body.

9. The system for recycling sodium acetate trihydrate as claimed in claim 8, characterized in that: A first extraction mixing box is arranged at one end of the first mixed extraction tube, a plurality of first extraction branch pipes are arranged on the first extraction mixing box, and a first flow limiting valve is arranged on the first extraction branch pipe; a second extraction mixing box is arranged at one end of the second mixed extraction tube, a plurality of second extraction branch pipes are arranged on the second extraction mixing box, and a second flow limiting valve is arranged on the second extraction branch pipe.

10. The system for recycling sodium acetate trihydrate as claimed in claim 8, characterized in that: A first heat exchange jacket is arranged on the side wall of the first tower body, and a heating cavity is formed between the first heat exchange jacket and the first tower body; a second heat exchange jacket is arranged on the side wall of the second tower body, and a heating cavity is formed between the second heat exchange jacket and the second tower body.

Images