Residual solvent recovery device for long-carbon-chain dicarboxylic acid

Abstract

The invention provides a long carbon chain dicarboxylic acid residual solvent recovery device which comprises a centrifugal machine for generating a long carbon chain dicarboxylic acid crude product, the centrifugal machine is connected with a preheating box for preheating the long carbon chain dicarboxylic acid crude product, an intermediate pipe assembly is arranged in the preheating box, and the intermediate pipe assembly is connected with a buffer box; the middle pipe assembly is connected with a plurality of heating boxes which are arranged in sequence, and crystal separation assemblies are arranged in the heating boxes and are arranged on the rails; the multiple heating boxes are connected with the liquid discharging pipe assembly and the liquid pumping pipe assembly, the liquid discharging pipe assembly is connected with the middle pipe assembly, and the liquid pumping pipe assembly is connected with the preheating box through the temporary storage box. And a drying assembly for removing the humidity of the long carbon chain dicarboxylic acid is also arranged above the plurality of rails. The device for recovering the residual solvent of the long-carbon-chain dicarboxylic acid, provided by the invention, can improve the heating efficiency of a crude solution of the long-carbon-chain dicarboxylic acid, reduce the energy consumption of the heating box and improve the crystallization production efficiency of the long-carbon-chain dicarboxylic acid.

Description

Technical Field

[0001] The invention belongs to the technical field of solvent recovery and utilization, and particularly relates to a residual solvent recovery device for long-chain dibasic acids. Background Art

[0002] Long-chain dibasic acids usually refer to organic compounds with carboxyl groups at both ends of the straight carbon chain. It is customary to call dibasic acids with more than ten carbon atoms long-chain dibasic acids. They are a type of fine chemical products with important and extensive industrial uses. The demand for long-chain dibasic acids will continue to increase at home and abroad, and their market potential is huge. At present, the production method of long-chain dibasic acids in China mainly adopts biological fermentation, but the fermentation broth contains a small amount of bacterial protein, pigment and other types of miscellaneous acids, which seriously affect the purity and quality of the product. Therefore, the refining process of dibasic acids is an important technical link in the production of long-chain dibasic acids by biological fermentation, which is related to the yield of the production process and the quality of the product.

[0003] The long-chain dicarboxylic acids produced by microbial fermentation are mainly purified by recrystallization using a solvent method, and the solvents mainly include acetic acid, methanol, ethanol, ethyl acetate, butyl acetate, etc. Experiments have shown that acetic acid is superior to other organic solvents in terms of refining yield, refining cost, and product quality. In the prior art, the crude long-chain dicarboxylic acid prepared by the fermentation method is used as a raw material, and more than 90wt% of acetic acid is used as a solvent. First, decolorization, filtration, and crystallization separation are performed. The resulting filter cake is kept in hot water at 70℃ to 100℃ for 120 minutes, cooled to 30℃ to 50℃, centrifuged, and dried. However, there are still the following technical problems:

[0004] (1) The long-chain dibasic acid product after refinement has the problem of insufficient monoacid content and high acetic acid residue, which cannot meet the stringent requirements of the long-chain nylon, i.e., bio-based polyamide fiber industry for the purity of long-chain dibasic acid products. Although the current high-temperature water washing treatment can remove some acetic acid residues, the washing temperature is only 70°C to 100°C, which does not reach the boiling point of water (less than 100°C) and does not reach the azeotropic state. Therefore, the hydrogen bond between the wet long-chain dibasic acid product and acetic acid is not completely destroyed, and the washing effect on the acetic acid residue is very small. The presence of residual acetic acid has an adverse effect on the application of long-chain dibasic acids;

[0005] The Chinese invention patent with application number 2023116322729 discloses a method for refining a long-chain dibasic acid. Although the azeotropic point can be reached, the long-chain dibasic acid is only washed with heated running water without external force, so that a certain amount of acetic acid still exists in the long-chain dibasic acid fine solution, and increasing the washing time will waste more water;

[0006] (2) The high-temperature water washing process requires a series of processes such as heating, heat preservation, and cooling. The heating process not only consumes a large amount of heat energy, but this heat energy also needs to be taken away by circulating water. The water consumption of circulating water is too large, which increases production costs and energy consumption;

[0007] Therefore, how to efficiently and quickly remove the residual acetic acid in the long-chain dibasic acid and reduce energy consumption has become the key technical problem to be solved in this solution. Summary of the invention

[0008] The purpose of the present invention is to provide a residual solvent recovery device for long-chain dibasic acids, which solves the technical problem of how to efficiently and quickly remove residual acetic acid in long-chain dibasic acids, reduces energy consumption, and finally obtains refined long-chain dibasic acids.

[0009] The purpose of the present invention is to provide a residual solvent recovery device for long-chain dibasic acids, which solves the technical problems of how to improve the heating efficiency of a crude solution of long-chain dibasic acids and reduce the energy consumption of a heating box, thereby improving the crystallization production efficiency of long-chain dibasic acids.

[0010] A residual solvent recovery device for a long-chain dibasic acid comprises a centrifuge for generating a crude long-chain dibasic acid product, the centrifuge is connected to a preheating box for preheating the crude long-chain dibasic acid product, an intermediate pipe assembly is arranged inside the preheating box, and the intermediate pipe assembly is connected to the buffer box;

[0011] The intermediate pipe assembly is connected to a plurality of heating boxes arranged in sequence, a crystal separation assembly is arranged inside the heating box, a track is horizontally passed through the bottom end of the heating box, and the crystal separation assembly is arranged on the track;

[0012] The plurality of heating boxes are connected to a liquid discharge pipe assembly and a liquid extraction pipe assembly, the liquid discharge pipe assembly is connected to the intermediate pipe assembly, the liquid extraction pipe assembly is connected to the preheating box through a buffer box, and the crystallization waste liquid is arranged in the buffer box;

[0013] A drying component for removing moisture from the long carbon chain dibasic acid is also arranged above the plurality of tracks.

[0014] The intermediate tube assembly comprises an intermediate tube 1 and an intermediate tube 2 which are tightly fitted together on the outside, and the intermediate tube 1 and the intermediate tube 2 are both bent inside the preheating box;

[0015] One end of the intermediate tube is connected to a centrifuge, and a crude solution of a long carbon chain dibasic acid is introduced into the intermediate tube;

[0016] One end of the intermediate tube 2 is connected to the buffer box, and the crystallization waste liquid is introduced into the inside;

[0017] The flow direction of the crude long-chain dibasic acid solution is opposite to the flow direction of the crystallization waste liquid.

[0018] The crystal separation assembly includes a lower movable box arranged on the track by a power wheel, an upper movable box embedded in the lower movable box for vertical movement, and a lifting cylinder connected to the top of the upper movable box, wherein the lifting cylinder is fixedly connected to the inner top surface of the heating box;

[0019] A filter assembly is arranged inside the upper movable box, and the filter assembly includes a horizontally arranged filter plate and a vertically arranged lifting cylinder 2. The free end of the lifting cylinder 2 is vertically fixedly connected to the filter plate, and the top of the lifting cylinder 2 is fixedly connected to the top of the upper movable box. The edge of the filter plate is fitted with the inner side surface of the upper movable box, and an agitator is also arranged on the upper end surface of the filter plate.

[0020] The liquid discharge pipe assembly includes a liquid inlet pipe 1 whose one end is connected to the other end of the intermediate pipe 1, a liquid inlet pump connected to the other end of the liquid inlet pipe 1, and a liquid inlet pipe 2 whose one end is connected to the liquid inlet pump, the other end of the liquid inlet pipe 2 is arranged through a plurality of heating boxes, and the outer side of the liquid inlet pipe 1 is connected to one end of the clean water pipe;

[0021] A plurality of injection pipes are arranged on the side of the second liquid inlet pipe, and the plurality of injection pipes are distributed in different heating boxes, and the bottom ends of the injection pipes are connected to the lower end of the upper movable box;

[0022] Solenoid valves are arranged on the first liquid inlet pipe, the clean water pipe, the second liquid inlet pipe and the injection pipe.

[0023] The liquid extraction pipe assembly includes a suction pipe 2 with one end passing through the plurality of heating boxes, a suction pump connected to the other end of the suction pipe 2, a suction pipe 1 connected to the suction pump at one end, and the other end of the suction pipe 1 connected to the cache box;

[0024] A plurality of suction hoses are arranged on the outer side of the second suction pipe, and the bottom ends of the suction hoses are fixed on the filter plate.

[0025] The drying component includes a lower pressure plate above a plurality of horizontally arranged tracks, a pushing cylinder respectively fixed at both ends of the lower pressure plate, a sponge fixed on the bottom surface of the lower pressure plate, and an air duct arranged above the lower pressure plate, one end of the air duct is connected to the fan, and the outer side of the air duct is connected to a plurality of protruding tubes, one end of the protruding tube passes through the lower pressure plate and extends into the interior of the sponge.

[0026] A non-woven fabric is arranged above the lower movable box, one end of the non-woven fabric is fixed to the outside of one end of the lower movable box, the other end of the non-woven fabric is draped over the outside of the other end of the lower movable box and is a free end, and both sides of the non-woven fabric are separately bonded to the two inner sides of the lower movable box.

[0027] A cabinet door is arranged on the outside of the heating box, and the cabinet door is connected to the opening and closing structure;

[0028] The opening and closing structure includes fixed blocks respectively fixed on both sides of the cabinet door, a telescopic cylinder 2 whose free ends are hinged to the fixed blocks, and a telescopic cylinder 1 whose free ends are hinged to the outer side of the telescopic cylinder 2. The bottom ends of the telescopic cylinder 1 and the telescopic cylinder 2 are fixed to the outer side of the cabinet door.

[0029] Preferably, the power systems in this solution are all connected to a PLC controller for unified control.

[0030] The positive effects of the present invention are as follows:

[0031] (1) The intermediate pipe assembly is provided in this solution, which has the following technical effects:

[0032] First, the intermediate tube 1 and the intermediate tube 2 are placed together, and the long carbon chain dibasic acid crude solution is preheated by using the crystallization waste liquid at a high temperature, which not only speeds up the heating speed of the long carbon chain dibasic acid crude solution, but also realizes the reuse of the crystallization waste liquid;

[0033] Second, the intermediate tubes 1 and 2 are bent in the preheating box, which helps to increase the contact time between the crystallization waste liquid and the long carbon chain dibasic acid solution and ensure the continuity of preheating;

[0034] (2) A crystallization separation component is provided, which has the following technical effects:

[0035] First, the crystallization tank is designed to be a separate structure, that is, it includes an upper movable box and a lower movable box. The upper movable box is used to accommodate the long-chain dibasic acid solution, and the lower movable box is used to accommodate the long-chain dibasic acid crystals, which is conducive to the rapid separation of the crystals and the crystallization waste liquid, and also helps the subsequent cleaning of the crystallization tank;

[0036] Second, a filter plate is arranged in the upper movable box, which strongly presses the crystals to quickly squeeze out the water in the crystals, and cooperates with the liquid extraction pipe assembly to extract the crystal waste liquid with a suction hose. This separation method avoids the residue of crystals in the crystal waste liquid, which is different from the running water cleaning process;

[0037] Third, since some long carbon chain dibasic acid crystals may be adhered to the bottom surface of the filter plate, when the lower movable box is drawn out and separated from the upper movable box, one end edge of the lower movable box scrapes off the long carbon chain dibasic acid crystals on the bottom surface of the filter plate, thereby avoiding the waste of the long carbon chain dibasic acid crystals;

[0038] (3) A lower movable box is provided, and cooperates with the track at the bottom, which has the following technical effects:

[0039] First, the lower movable box can move freely on the track, which greatly facilitates the transportation of crystals;

[0040] Second, a non-woven fabric is arranged on the lower movable box. On the one hand, the bottom surface of the upper movable box is pressed on the non-woven fabric, which helps to improve the sealing strength between the upper movable box and the lower movable box and prevents the crystallization waste liquid from seeping out of the lower movable box. On the other hand, when the long carbon chain dibasic acid crystals are discharged, people lift one end of the non-woven fabric to take out the long carbon chain dibasic acid crystals, which is convenient for taking and placing the crystals.

[0041] (4) A drying component is provided, which has the following technical effects:

[0042] First, when the lower movable box moves to the bottom of the sponge, the sponge descends and contacts the lower movable box, absorbing the remaining liquid in the long-chain dibasic acid crystals, thereby drying the long-chain dibasic acid;

[0043] Secondly, under the effect of blowing air in the air duct, on the one hand, the long carbon chain dibasic acid crystals adhering to the bottom surface of the sponge are blown down into the moving box, and on the other hand, the sponge is dried;

[0044] (5) A liquid discharge pipe assembly is provided, which not only discharges the crude long-chain dibasic acid solution, but also heats the solution to a suitable temperature without moving the crystallization tank, thereby separating the long-chain dibasic acid from acetic acid. The long-chain dibasic acid crystals can also be cleaned with clean water. Finally, the liquid extraction pipe assembly is used to extract the aqueous solution, thereby reducing water consumption, being convenient and quick, and having compact operation steps, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The structure of the solvent recovery device in the present invention is shown in FIG. Figure 1 .

[0046] Figure 2 The structure of the solvent recovery device in the present invention is shown in FIG. Figure 2 .

[0047] Figure 3 It is a schematic diagram of the internal structure of the heating box in the present invention.

[0048] Figure 4 It is a schematic diagram of the connection structure of the upper movable box in the present invention.

[0049] Figure 5 The structure of the preheating box in the present invention is shown in FIG. Figure 1 .

[0050] Figure 6 The structure of the preheating box in the present invention is shown in FIG. Figure 2 .

[0051] Figure 7 It is a schematic diagram of the structure of the drying component in the present invention.

[0052] Figure 8 It is a schematic diagram of the connection structure between the lower movable box and the non-woven fabric in the present invention.

[0053] Among them, the accompanying drawings are marked as follows: Among them, the accompanying drawings are marked as follows: 1. track; 2. lower pressure plate; 21. pushing cylinder; 3. sponge; 4. centrifuge; 5. preheating box; 6. intermediate pipe assembly; 61. intermediate pipe one; 62. intermediate pipe two; 7. liquid inlet pipe one; 71. injection pipe; 72. solenoid valve; 8. clean water pipe; 9. heating box; 91. lifting cylinder one; 921. suction hose; 93. telescopic cylinder one; 94. telescopic cylinder two; 95. fixing block; 96. upper movable box; 961. lifting cylinder two; 962. filter plate; 97. lower movable box; 971. non-woven fabric; 98. power wheel; 10. suction pipe one; 11. opening and closing structure; 12. liquid inlet pipe two; 13. suction pipe two; 14. suction pump; 15. air duct; 151. protruding pipe. DETAILED DESCRIPTION

[0054] In order to more clearly illustrate the technical features of this solution, this solution is described below through specific implementation methods.

[0055] See also Figure 1-Figure 8 A residual solvent recovery device for a long-chain dibasic acid comprises a centrifuge 4 for generating a crude long-chain dibasic acid product, the centrifuge 4 is connected to a preheating box 5 for preheating the crude long-chain dibasic acid product, an intermediate pipe assembly 6 is arranged inside the preheating box 5, and the intermediate pipe assembly 6 is connected to a buffer box;

[0056] The middle pipe assembly 6 is connected to a plurality of heating boxes 9 arranged in sequence, a crystal separation assembly is arranged inside the heating box 9, a track 1 is horizontally passed through the bottom end of the heating box 9, and the crystal separation assembly is arranged on the track 1;

[0057] A plurality of heating boxes 9 are connected to the liquid discharge pipe assembly and the liquid extraction pipe assembly, the liquid discharge pipe assembly is connected to the intermediate pipe assembly 6, and the liquid extraction pipe assembly is connected to the preheating box 5 through a buffer box, and the crystallization waste liquid is arranged in the buffer box;

[0058] A drying component for removing moisture from the long carbon chain dibasic acid is also arranged above the multiple tracks 1 .

[0059] The intermediate tube assembly 6 includes an intermediate tube 1 61 and an intermediate tube 2 62 which are tightly fitted together on the outside, and the intermediate tube 1 61 and the intermediate tube 2 62 are both bent inside the preheating box 5;

[0060] One end of the intermediate tube 61 is connected to the centrifuge 4, and a crude solution of a long carbon chain dibasic acid is introduced into the centrifuge 4;

[0061] One end of the second intermediate tube 62 is connected to the buffer box, and the crystallization waste liquid is introduced into the inside;

[0062] The flow direction of the crude long-chain dibasic acid solution is opposite to that of the crystallization waste liquid.

[0063] The crystal separation assembly includes a lower movable box 97 which is moved on the track 1 by a power wheel 98, an upper movable box 96 which is embedded in the lower movable box 97 and can be moved up and down, and a lifting cylinder 91 which is connected to the top of the upper movable box 96. The lifting cylinder 91 is fixedly connected to the inner top surface of the heating box 9.

[0064] A filter assembly is arranged inside the upper movable box 96, and the filter assembly includes a horizontally arranged filter plate 962 and a vertically arranged lifting cylinder 961. The free end of the lifting cylinder 961 is vertically fixedly connected to the filter plate 962, and the top of the lifting cylinder 961 is fixedly connected to the top of the upper movable box 96. The edge of the filter plate 962 is fitted with the inner side surface of the upper movable box 96, and an agitator is also arranged on the upper end surface of the filter plate 962.

[0065] The stirring shaft of the stirrer slightly protrudes from the bottom end of the filter plate, which can stir the long-chain dibasic acid and accelerate the floating of acetic acid. The stirrer is a high-temperature resistant micro stirring structure.

[0066] The liquid discharge pipe assembly includes a liquid inlet pipe 7 connected at one end to the other end of the intermediate pipe 61, a liquid inlet pump connected to the other end of the liquid inlet pipe 7, and a liquid inlet pipe 12 connected at one end to the liquid inlet pump. The other end of the liquid inlet pipe 12 passes through a plurality of heating boxes 9, and the outer side of the liquid inlet pipe 7 is connected to one end of the clean water pipe 8.

[0067] A plurality of injection pipes 71 are provided on the side of the second liquid inlet pipe 12, and the plurality of injection pipes 71 are distributed in different heating boxes 9, and the bottom ends of the injection pipes 71 are connected to the lower end of the upper movable box 96;

[0068] Solenoid valves are provided on the liquid inlet pipe 1 7 , the clean water pipe 8 , the liquid inlet pipe 2 12 , and the injection pipe 71 .

[0069] The liquid extraction pipe assembly includes a suction pipe 13 with one end passing through a plurality of heating boxes 9, a suction pump 14 connected to the other end of the suction pipe 13, a suction pipe 10 connected to the suction pump 14 at one end, and the other end of the suction pipe 10 connected to the buffer box;

[0070] The outside of the suction pipe 13 is connected to a plurality of suction hoses 921 , one end of the suction hose 921 is connected to the outside of the suction pipe 13 , and the other end is fixed on the filter plate 962 for sucking and discharging the filtrate (solvent) on the filter plate 962 .

[0071] The drying component includes a lower pressure plate 2 above a plurality of horizontally arranged tracks 1, a pushing cylinder 21 respectively fixed at both ends of the lower pressure plate 2, a sponge 3 fixed on the bottom surface of the lower pressure plate 2, and an air duct 15 arranged above the lower pressure plate 2, one end of the air duct 15 is connected to the fan, and the outer side of the air duct 15 is connected to a plurality of protruding tubes 151, one end of the protruding tube 151 passes through the lower pressure plate 2 and extends into the interior of the sponge 3.

[0072] A non-woven fabric 971 is provided above the lower movable box 97, one end of the non-woven fabric 971 is fixed to the outer side of one end of the lower movable box 97, the other end of the non-woven fabric 971 is laid on the outer side of the other end of the lower movable box 97 and is a free end, and both sides of the non-woven fabric 971 are separately fitted with the two inner sides of the lower movable box 97.

[0073] A cabinet door is provided on the outside of the heating box 9, and the cabinet door is connected to the opening and closing structure 11;

[0074] The opening and closing structure 11 includes fixed blocks 95 respectively fixed on both sides of the cabinet door, a telescopic cylinder 94 whose free ends are hinged to the fixed blocks 95, and a telescopic cylinder 1 93 whose free ends are hinged to the outer side of the telescopic cylinder 2 94. The bottom ends of the telescopic cylinder 1 93 and the telescopic cylinder 2 94 are fixed to the outer side of the cabinet door.

[0075] In this scheme, the removal of acetic acid from the long-chain dibasic acid is achieved by immediate water washing and filtration, which is more efficient.

[0076] The specific working process of the present invention is:

[0077] When in use, the crude long-chain dibasic acid is separated and cleaned after crystallization (preliminary treatment: the crude long-chain dibasic acid, acetic acid and activated carbon are put into a decolorization tank, kept at 80-83°C for 120 minutes for decolorization, and the filtrate enters the crystallization tank through a filter press; the obtained dibasic acid clear liquid is forced to cool to 72-75°C with cooling water in the crystallization tank, kept warm for 180 minutes, and after the insulation is completed, forced to cool to 30-35°C for discharging, and the long-chain dibasic acid is crystallized by cooling and crystallization; the obtained crystal material is then centrifuged and filtered to obtain a dibasic acid filter cake, which is cleaned in situ in a centrifuge, and the acetic acid on the surface of the dibasic acid filter cake is dissolved in the cleaning water). At this time, the preliminary treatment process of the crude long-chain dibasic acid has been completed. This scheme is mainly designed for the removal of residual acetic acid in the later stage. The centrifuge 4 is connected to the preheating box 5.

[0078] At this time, the acetic acid on the surface of the crude dibasic acid filter cake is dissolved in the washing water, and the crude long-chain dibasic acid crystal material with the washing water is extracted from the centrifuge 4 through the liquid inlet pump, and enters the liquid inlet pipe 1 7 and the liquid inlet pipe 2 12 through the intermediate pipe 1 61, and the lower movable box 97 and the upper movable box 96 in the multiple heating boxes 9 are filled with the long-chain dibasic acid crude solution by adjusting the solenoid valves on the liquid inlet pipe 1 7, the liquid inlet pipe 2 12, and the injection pipe 71, wherein a solenoid valve is provided between any two adjacent heating boxes 9 on the liquid inlet pipe 2 12;

[0079] At the same time, one end of the intermediate pipe 2 62 is connected to a cache box, which contains some preheated water (at this time, crystallization waste liquid has not yet been generated, so for the purpose of preheating, a portion of preheated water can be placed in the cache box in advance to heat the long-chain dibasic acid solution after the reaction. When the crystallization waste liquid is generated, it is sucked into the cache box. At this time, the crystallization waste liquid is stored in the cache box. After the whole process is circulated, the crystallization waste liquid circulates in the intermediate pipe 2 62), the cache box is connected to a cooling pump, and the cooling pump pumps the cooling liquid into the intermediate pipe 2 62. The other end of the intermediate pipe 2 62 discharges the cooling liquid into the collection pool.

[0080] A liquid discharge pipe assembly is provided, which not only realizes the discharge of the crude long-chain dibasic acid solution into the lower movable box 97 and the upper movable box 96, but also specifically, the electromagnetic valve 72 on the injection pipe 71 is opened, the liquid inlet pump is operated, and the crude long-chain dibasic acid solution is introduced into the injection pipe 71, and the bottom end of the injection pipe 71 is connected to the lower end of the upper movable box 96, so that the crude long-chain dibasic acid solution enters the upper movable box 96 and the lower movable box 97. Moreover, under the premise of not moving the crystallization tank (including the upper movable box 96 and the lower movable box 97), the long-chain dibasic acid crystals can be cleaned with clean water. Finally, the aqueous solution is extracted by using the liquid extraction pipe assembly, which is convenient and fast, with compact operation steps and reduced costs; specifically, the solenoid valve on the clean water pipe 8 is opened, and clean water is introduced into the clean water pipe 8, and enters the upper movable box 96 and the lower movable box 97 along the liquid inlet pipe 7 and the injection pipe 71, and contacts with the long carbon chain dibasic acid crystals to achieve the purpose of cleaning. After cleaning, the acetic acid separated from the long carbon chain dibasic acid is dissolved in the clean water (under the azeotropic state, the hydrogen bond binding force between the wet long carbon chain dibasic acid and the acetic acid is completely destroyed), and then the aqueous solution is quickly sucked away;

[0081] The working principle of the liquid suction pipe assembly is that when the filter plate 962 presses down the long-chain dibasic acid crystals, the crystallized waste liquid is pressed and filtered to the top of the filter plate 962. At this time, under the action of the suction hose 921, the suction pipe 13 and the suction pump 14, the crystallized waste liquid is sucked.

[0082] A crystallization separation component is provided, and the crystallization tank is designed to be a separate structure, that is, it includes an upper movable box 96 and a lower movable box 97, the upper movable box 96 is used to accommodate the long-chain dibasic acid solution, and the lower movable box 97 is used to accommodate the long-chain dibasic acid crystals, which is helpful for the rapid separation of the crystals and the crystallization waste liquid, and also helps the subsequent cleaning of the crystallization tank; a filter plate 962 is provided in the upper movable box 96, the filter plate 962 presses the crystals, cooperates with the liquid extraction pipe component, and uses the suction hose 921 to extract the crystallization waste liquid. This separation method avoids the residue of crystals in the crystallization waste liquid;

[0083] Specifically, the filter plate 962 slides up and down in the upper movable box 96, and the initial position of the filter plate 962 is above the long carbon chain dibasic acid solution. When the long carbon chain dibasic acid is crystallized, it will inevitably sink into the lower movable box 97. After the crystallization is completed, the filter plate 962 is pressed down, and the crystallized waste liquid is filtered and rises to the top of the filter plate 962, thereby achieving rapid separation of the crystals and the crystallized waste liquid.

[0084] When the crystallized waste liquid rises above the filter plate 962, the suction pump 14 is started, and the crystallized waste liquid passes through the suction hose 921 and the suction tube 13 in turn, enters the suction tube 10, and then enters the buffer box. One end of the intermediate tube 62 is connected to the buffer box, and then enters the intermediate tube 62 to participate in the preheating process of the newly generated long-chain dibasic acid solution.

[0085] Since some long-chain dicarboxylic acid crystals may be stuck to the bottom surface of the filter plate 962, when the lower movable box 97 is pulled out and separated from the upper movable box 96, the edge of one end of the lower movable box 97 scrapes off the long-chain dicarboxylic acid crystals on the bottom surface of the filter plate 962, thereby avoiding the waste of long-chain dicarboxylic acid crystals; a lower movable box 97 is provided, and cooperates with the track 1 at the bottom, and the lower movable box 97 moves freely on the track 1, which greatly facilitates the transportation of the crystals; a non-woven fabric 971 is provided on the lower movable box 97. On the one hand, the bottom surface of the upper movable box 96 is pressed on the non-woven fabric 971, which helps to increase the sealing strength between the upper movable box 96 and the lower movable box 97, and avoids the seepage of crystalline waste liquid on the lower movable box 97. On the other hand, when discharging the long-chain dicarboxylic acid crystals, people lift one end of the non-woven fabric 971 to scoop out the long-chain dicarboxylic acid crystals, thereby facilitating the taking and placing of the crystals.

[0086] It should be noted that when the upper movable box 96 and the lower movable box 97 are separated, the lifting cylinder 1 91 is started to drive the upper movable box 96 to move upward to achieve the separation of the two. At this time, the crystallization waste liquid has been completely extracted. After the two are separated, there is no need to worry about the crystallization waste liquid overflowing from the lower movable box 97; since the lifting cylinder 2 961 is fixed in the upper movable box 96, the lifting cylinder 2 961 also rises accordingly, and the filter plate 962 is horizontally fixed at the free end of the lifting cylinder 2 961. At this time, the bottom of the filter plate 962 The surface is separated from the long carbon chain dibasic acid crystals, and there may be a small amount of long carbon chain dibasic acid crystals stuck to it. When the lower movable box 97 is pulled out of the heating box, the lifting cylinder 961 is adjusted to drive the filter plate 962 to move, so that the bottom surface of the filter plate 962 is flush with the upper end surface of the lower movable box 97. In this way, when the lower movable box 97 moves outward, the edge of one end of the lower movable box 97 scrapes off the long carbon chain dibasic acid crystals on the bottom surface of the filter plate 962, and the scraped long carbon chain dibasic acid crystals re-enter the lower movable box 97 to achieve collection.

[0087] After the crystallization is completed, the crystallization waste liquid is extracted by the suction hose 921 and discharged into the buffer box. When the subsequent long-chain dibasic acid crude product is generated in the centrifuge and transmitted to the preheating box 5, the long-chain dibasic acid crude product solution is preheated by the crystallization waste liquid at a low temperature, which not only accelerates the heating rate of the long-chain dibasic acid crude product solution, but also realizes the reuse of the crystallization waste liquid; as mentioned above, one end of the intermediate tube 1 61 is connected to the centrifuge 4, and the long-chain dibasic acid crude product solution is introduced into the interior, and one end of the intermediate tube 2 62 is connected to the buffer box, and the crystallization waste liquid is introduced into the interior, the flow direction of the long-chain dibasic acid crude product solution is opposite to the flow direction of the crystallization waste liquid, the intermediate tube 1 61 and the intermediate tube 2 62 are tightly fitted together, and the heated crystallization waste liquid preheats the newly generated long-chain dibasic acid crude product solution.

[0088] A drying component is provided. When the lower movable box 97 moves to the bottom of the sponge, the cylinder 21 is pushed to drive the lower pressure plate 2 to descend. The lower pressure plate 2 drives the sponge 3 to descend and makes the sponge 3 contact with the lower movable box 97, so as to absorb the solvent in the long-chain dibasic acid crystals and realize the drying of the long-chain dibasic acid. Under the effect of blowing air in the air duct 15, on the one hand, the long-chain dibasic acid crystals adhering to the bottom surface of the sponge 3 are blown into the lower movable box 97, and on the other hand, the sponge 3 is dried.

[0089] In order to make this solution produce better technical effects, the following explanation is given:

[0090] (1) Control the moisture content of crude long-chain dibasic acid to less than 1%;

[0091] (2) The present invention controls the solvent concentration of acetic acid to 84wt%-88wt%;

[0092] (3) The heating box 9 continuously heats the wet product of the long carbon chain dibasic acid to at least 103°C (generally 102°C-106°C).

[0093] Technical features not described in the present invention can be achieved through or by adopting existing technologies and will not be described in detail here. Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by ordinary technicians in this technical field within the essential scope of the present invention should also fall within the scope of protection of the present invention.

Claims

1. A residual solvent recovery device for a long carbon chain dibasic acid, characterized in that: The invention comprises a centrifuge (4) for generating a crude long-chain dibasic acid product, wherein the centrifuge (4) is connected to a preheating box (5) for preheating the crude long-chain dibasic acid product, an intermediate pipe assembly (6) is arranged inside the preheating box (5), and the intermediate pipe assembly (6) is connected to the buffer box; The intermediate tube assembly (6) is connected to a plurality of heating boxes (9) arranged in sequence, a crystallization separation assembly is arranged inside the heating box (9), a track (1) is horizontally passed through the bottom end of the heating box (9), and the crystallization separation assembly is arranged on the track (1); The plurality of heating boxes (9) are connected to a liquid discharge pipe assembly and a liquid extraction pipe assembly, the liquid discharge pipe assembly is connected to the intermediate pipe assembly (6), the liquid extraction pipe assembly is connected to the preheating box (5) via a buffer box, and the buffer box contains crystallization waste liquid; A drying component for removing moisture from the long-chain dibasic acid is also provided above the plurality of tracks (1).

2. The residual solvent recovery device for a long carbon chain dibasic acid according to claim 1, characterized in that: The intermediate tube assembly (6) comprises an intermediate tube 1 (61) and an intermediate tube 2 (62) which are tightly fitted together on the outside, and the intermediate tube 1 (61) and the intermediate tube 2 (62) are both bent inside the preheating box (5); One end of the intermediate tube 1 (61) is connected to the centrifuge (4), and a crude solution of a long carbon chain dibasic acid is introduced into the centrifuge; One end of the second intermediate pipe (62) is connected to the buffer box, and the crystallization waste liquid is introduced into the interior; The flow direction of the crude long-chain dibasic acid solution is opposite to the flow direction of the crystallization waste liquid.

3. The residual solvent recovery device for a long carbon chain dibasic acid according to claim 2, characterized in that: The crystal separation assembly comprises a lower movable box (97) arranged on the track (1) for movement via a power wheel (98), an upper movable box (96) movably embedded in the lower movable box (97), and a lifting cylinder (91) connected to the top of the upper movable box (96), wherein the lifting cylinder (91) is fixedly connected to the inner top surface of the heating box (9); A filter assembly is arranged inside the upper movable box (96), and the filter assembly includes a horizontally arranged filter plate (962) and a vertically arranged lifting cylinder (961). The free end of the lifting cylinder (961) is vertically fixedly connected to the filter plate (962), the top of the lifting cylinder (961) is fixedly connected to the top of the upper movable box (96), the edge of the filter plate (962) is in contact with the inner side surface of the upper movable box (96), and an agitator is also arranged on the upper end surface of the filter plate (962).

4. The residual solvent recovery device for a long carbon chain dibasic acid according to claim 3, characterized in that: The liquid discharge pipe assembly comprises a liquid inlet pipe (7) having one end connected to the other end of the intermediate pipe (61), a liquid inlet pump connected to the other end of the liquid inlet pipe (7), and a liquid inlet pipe (12) having one end connected to the liquid inlet pump, wherein the other end of the liquid inlet pipe (12) passes through a plurality of heating boxes (9), and the outer side of the liquid inlet pipe (7) is connected to one end of a clean water pipe (8); A plurality of injection pipes (71) are arranged on the side of the second liquid inlet pipe (12), and the plurality of injection pipes (71) are distributed in different heating boxes (9), and the bottom ends of the injection pipes (71) are connected to the lower end of the upper movable box (96); Solenoid valves are provided on the first liquid inlet pipe (7), the clean water pipe (8), the second liquid inlet pipe (12), and the injection pipe (71).

5. The residual solvent recovery device for a long carbon chain dibasic acid according to claim 2, characterized in that: The liquid extraction pipe assembly comprises a suction pipe 2 (13) having one end passing through the plurality of heating boxes (9), a suction pump (14) connected to the other end of the suction pipe 2 (13), a suction pipe 1 (10) having one end connected to the suction pump (14), and the other end of the suction pipe 1 (10) being connected to the buffer box; A plurality of suction hoses (921) are arranged on the outer side of the second suction pipe (13), and the bottom ends of the suction hoses (921) are fixed on the filter plate (962).

6. The residual solvent recovery device for a long carbon chain dibasic acid according to claim 1, characterized in that: The drying component comprises a lower pressure plate (2) above a plurality of horizontally arranged rails (1), a pushing cylinder (21) respectively fixed to both ends of the lower pressure plate (2), a sponge (3) fixedly arranged on the bottom surface of the lower pressure plate (2), and an air duct (15) arranged above the lower pressure plate (2), one end of the air duct (15) being connected to a fan, the outer side of the air duct (15) being connected to a plurality of protruding tubes (151), one end of the protruding tube (151) passing through the lower pressure plate (2) and extending into the interior of the sponge.

7. The residual solvent recovery device for long-chain dibasic acid according to claim 3, characterized in that: A non-woven fabric (971) is provided above the lower movable box (97), one end of the non-woven fabric (971) is fixed to the outside of one end of the lower movable box (97), the other end of the non-woven fabric (971) is draped over the outside of the other end of the lower movable box (97) and is a free end, and two sides of the non-woven fabric (971) are separately bonded to the two inner sides of the lower movable box (97).

8. The residual solvent recovery device for long-chain dibasic acid according to claim 1, characterized in that: The outer side of the heating box (9) is provided with a cabinet door, and the cabinet door is connected to the opening and closing structure (11); The opening and closing structure (11) comprises fixed blocks (95) respectively fixed on both sides of the cabinet door, a telescopic cylinder 2 (94) whose free ends are hinged to the fixed blocks (95), and a telescopic cylinder 1 (93) whose free ends are hinged to the outer side of the telescopic cylinder 2 (94), and the bottom ends of the telescopic cylinder 1 (93) and the telescopic cylinder 2 (94) are fixed to the outer side of the cabinet door.

Images