Lactic acid purification device and purification method

Abstract

The invention relates to the technical field of lactic acid purification, in particular to a lactic acid purification device and method.The device comprises a support and a stirring barrel arranged on the support, the stirring barrel is connected with a stirring motor fixed to the support, the device further comprises a stirring mechanism, and the stirring mechanism comprises a stirring shaft connected with the output end of the stirring motor; the stirring shaft extends into the stirring barrel, and a stirring arm is arranged on the stirring shaft; the agent supply mechanism comprises a pump body arranged on the bracket, the pump body is connected with an agent supply tank arranged on the bracket, the pump body is connected with a rotating joint through a pipeline, the rotating joint comprises a rotating joint A and a rotating joint B, the rotating joint A is connected with an agent supply pipe A, the agent supply pipe A is connected with an agent supply frame A, and the agent supply frame A is fixed on the stirring shaft; and the rotary joint B is arranged in the stirring barrel and is connected with a flocculant supply pipe B. The device has the advantages that the purification of lactic acid can be realized, the working efficiency is high, the flocculant is uniformly dispersed, and the filtering effect is good.

Description

Technical Field

[0001] The invention relates to the technical field of lactic acid purification, and in particular to a lactic acid purification device and a purification method. Background Art

[0002] Lactic acid is a raw material widely used in food, medical, chemical, daily chemical and new materials. Polylactic acid (PLA) synthesized from it has good biodegradability and biocompatibility, and is the key direction for the development of environmentally friendly polymer materials in the future. In order to prepare PLA with excellent performance, high-purity lactic acid is needed to synthesize lactide monomers.

[0003] Industrially, lactic acid is generally prepared by microbial fermentation, which uses starch, glucose, etc. as raw materials, inoculates Rhizopus oryzae or lactic acid bacteria, and generates a fermentation broth containing lactic acid or lactate through fermentation, which is then separated. The composition of lactic acid fermentation broth is very complex. In addition to lactic acid, it also contains a large amount of bacteria, starch, protein, sugar, pigment, inorganic salt, etc., which makes purification difficult. At present, the main methods for separating and extracting lactic acid from fermentation broth include crystallization separation technology, esterification hydrolysis method, extraction method, molecular distillation method, membrane separation method, etc.

[0004] The patent publication number CN116474425A was retrieved, and the patent name is a public material of a method and equipment for removing impurities for reducing the viscosity of lactic acid, and the patent specifically discloses the impurity removal equipment for reducing the viscosity of lactic acid, including: a base; a tank body, rotatably mounted on the base and extending in the horizontal direction, the tank body is suitable for containing lactic acid; a stirring mechanism, including a connecting shaft rotatably mounted inside the tank body and a stirring rod fixed on the connecting shaft, the connecting shaft having a slide groove and a through groove interconnected with the slide groove; a feeding mechanism, having an inner box body slidably mounted inside the slide groove, the inner box body is suitable for containing flocculant; a driving blade, fixed on the inner box body and extending from the through groove, and the position of the driving blade is staggered with the position of the stirring rod, when the driving blade rotates together with the connecting shaft, the inference generated by the driving blade causes the inner box body to slide along the length direction of the connecting shaft, so that the flocculant falls into the tank body. A method for removing impurities to reduce the viscosity of lactic acid comprises the following steps: weighing a flocculant according to the addition ratio of lactic acid to flocculant and putting it into the inner box of a feeding mechanism; heating the depolymerized lactic acid and adding it into the inner part of a tank through a feeding pipe; starting a stirring mechanism to make the feeding mechanism reciprocate inside the stirring mechanism until the flocculant inside the feeding mechanism and the lactic acid inside the tank are completely dissolved; stopping the stirring mechanism to time and keep warm; pre-coating a filter with prepared perlite or diatomaceous earth; after the insulation is completed, the lactic acid after flocculation and precipitation in the tank is discharged through a discharging pipe and filtered through the pre-coated filter.

[0005] By analyzing the above-mentioned public materials, it can be seen that the impurity removal operation of lactic acid can be achieved, but the addition of the flocculant cannot achieve a uniform effect. Because during the purification and impurity removal process of lactic acid, lactic acid has a certain viscosity, and it is necessary to evenly distribute the flocculant in the stirring cylinder in a timely manner to effectively purify lactic acid. In addition, the specific structure of filtration is not mentioned in the public materials, and filtration is an important link in the purification operation. Only after filtration can the required lactic acid be obtained. Summary of the Invention

[0006] In view of this, the present invention provides a lactic acid purification device, which can not only achieve the purification of lactic acid, but also has high working efficiency, uniform dispersion of the flocculant and good filtration effect.

[0007] To solve the above technical problems, the present invention provides a lactic acid purification device, including a bracket, and a stirring cylinder arranged on the bracket. The stirring cylinder is connected to a stirring motor fixed on the bracket, and further includes

[0008] a stirring mechanism, the stirring mechanism includes a stirring shaft connected to the output end of the stirring motor, the stirring shaft extends into the stirring cylinder, and stirring arms are arranged on the stirring shaft;

[0009] a reagent supply mechanism, the reagent supply mechanism includes a pump body arranged on the bracket, the pump body is connected to a reagent supply tank arranged on the bracket, the pump body is connected to a rotary joint through a pipeline, the rotary joint includes rotary joint A and rotary joint B, rotary joint A is connected to a reagent supply pipe A, the reagent supply pipe A is connected to a reagent supply rack A, the reagent supply rack A is fixed on the stirring shaft and arranged inside the stirring cylinder, rotary joint B is connected to a reagent supply pipe B, the reagent supply pipe B is connected to a reagent supply rack B, the reagent supply rack B is arranged on the stirring shaft, and the reagent supply rack B is arranged inside the stirring cylinder;

[0010] a filtering mechanism, the filtering mechanism includes a filter arranged below the stirring cylinder, a discharge pipe is arranged between the stirring barrel and the filter, the filter includes a filter cover body connected to the discharge pipe, a roller is arranged below the filter cover body, the lower end of the roller is connected to a roller motor, a filter grate is arranged outside the roller motor, the filter grate is fixedly connected between the filter grate and the shell of the filter, and a material receiving bucket is arranged below the filter.

[0011] Further, the stirring shaft is of a hollow structure, one end is connected to the stirring motor, bearings are arranged on the stirring shaft, and a cover body is connected through the bearings. The cover body is fixedly connected to the stirring cylinder, and the stirring cylinder is fixedly connected to the bracket. The stirring arm is of a round rod structure and is fixed on the stirring shaft.

[0012] Further, a support plate is provided on the bracket, the pump body and the reagent supply tank are fixed on the support plate, the pump body is connected to the reagent supply tank through a pipeline, the output end of the pump body is connected to a reagent supply pipe A and a reagent supply pipe B, a reagent inlet A is provided on the rotary joint A, a reagent inlet B is provided on the rotary joint B, the reagent inlet A is connected to a reagent supply rack A through a pipeline provided inside the stirring shaft, and the reagent inlet B is connected to a reagent supply rack B through a pipeline provided inside the stirring shaft.

[0013] Further, the reagent supply rack A is of a hollow round rod structure, a reagent outlet A is provided on the outer side surface, the reagent supply rack A is parallel to the stirring shaft, the reagent supply rack B is of a hollow round rod structure, a reagent outlet B is provided on the outer side surface, the reagent supply rack B is parallel to the stirring shaft, the reagent supply rack A is distributed at the front part of the stirring shaft, and the reagent supply rack B is distributed at the rear part of the stirring shaft, for uniformly dispersing the flocculant in the stirring cylinder.

[0014] Further, the filter is of a hollow shell structure, a stabilizing frame is fixedly connected to the outside, the upper end of the filter is a filter cover body, the filter cover body is fixedly connected and communicated with the discharge pipe, and a valve is provided on the discharge pipe.

[0015] Further, leakage holes are provided on the filter grate, the leakage holes are uniformly distributed on the outer side of the drum, the outer side surface of the filter grate is fixedly connected to the shell of the filter, the drum motor is fixedly connected to the filter grate, and the output end of the drum motor is connected to the drum and drives the drum to rotate.

[0016] A lactic acid purification method, including the purification device as described above, is carried out according to the following steps:

[0017] Step 1: Heating, heating the depolymerized lactic acid.

[0018] Step 2: Adding a flocculant, after rising to a certain temperature, weighing the flocculant according to the addition ratio of lactic acid to the flocculant, and adding it to the heated lactic acid.

[0019] Step 3: Stirring and heat preservation, after adding the flocculant, stirring until the flocculant is dissolved, and stopping stirring and starting heat preservation timing.

[0020] Step 4: Precoating, precoating the filter with the prepared perlite or diatomite.

[0021] Step 5: Filtration, after the heat preservation ends, filtering while it is hot.

[0022] Step 6: Measuring the lactic acid content and viscosity, taking the lactic acid before and after impurity removal to measure its lactic acid content and viscosity, and recording and calculating the lactic acid loss rate.

[0023] The beneficial effects of the above technical solutions of the present invention are as follows:

[0024] 1. It can achieve the purification of lactic acid. By setting a stirring cylinder and a dosing mechanism for the flocculant, the lactic acid in the stirring cylinder can be flocculated and purified.

[0025] 2. It has high working efficiency, uniform dispersion of the flocculant, and good filtering effect. By adopting the method of a rotary joint, it can not only uniformly add the flocculant but also play a stirring role. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] By referring to the accompanying drawings and reading the following detailed description, the above and other objects, features, and advantages of the exemplary embodiments of the present invention will become readily understandable. In the drawings, several embodiments of the present invention are shown in an exemplary rather than restrictive manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0027] Figure 1 is a schematic structural diagram of the present invention;

[0028] Figure 2 is Figure 1 a schematic structural diagram from another perspective;

[0029] Figure 3 is the front view of the stirring mechanism;

[0030] Figure 4 is Figure 3 the axonometric view of;

[0031] Figure 5 is the sectional view of the stirring structure along the axis of the stirring shaft;

[0032] Figure 6 is the schematic structural diagram of the connection between the stirring shaft and the rotary joint;

[0033] Figure 7 is the schematic internal structure diagram of the filter;

[0034] In the figure: 1. Support; 2. Stirring cylinder; 3. Stirring motor; 4. Heating layer; 5. Heating wire; 6. Discharge pipe; 7. Filter; 8. Pump body; 9. Dosing pipe A; 10. Dosing pipe B; 11. Stabilizing frame; 12. Material storage bucket; 13. Support plate; 14. Dosing tank; 15. Rotary joint A; 16. Rotary joint B; 17. Stirring shaft; 18. Stirring arm; 19. Dosing rack A; 20. Cover body; 21. Bearing; 22. Dosing outlet A; 23. Dosing rack B; 24. Dosing outlet B; 25. Dosing inlet A; 26. Dosing inlet B; 27. Drum motor; 28. Filter cover body; 29. Drum; 30. Filter holes; 31. Filter grate; 32. Leak holes. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0036] As Figure 1-7 shown:

[0037] A lactic acid purification device includes a bracket 1 and a stirring cylinder 2 provided on the bracket 1. The stirring cylinder 2 is connected to a stirring motor 3 fixed on the bracket 1. It also includes a stirring mechanism, and the stirring mechanism includes a stirring shaft 17 connected to the output end of the stirring motor 3. The stirring shaft 17 extends into the stirring cylinder 2, and stirring arms 18 are provided on the stirring shaft 17; a dosing mechanism, the dosing mechanism includes a pump body 8 provided on the bracket 1. The pump body 8 is connected to a dosing tank 14 provided on the bracket 1. The pump body 8 is connected to a rotary joint through a pipeline. The rotary joint includes a rotary joint A 15 and a rotary joint B 16. The rotary joint A 15 is connected to a dosing pipe A 9. The dosing pipe A 9 is connected to a dosing rack A 19. The dosing rack A 19 is fixed on the stirring shaft 17 and is arranged inside the stirring cylinder 2. The rotary joint B 16 is connected to a dosing pipe B 10. The dosing pipe B 10 is connected to a dosing rack B 23. The dosing rack B 23 is arranged on the stirring shaft 17, and the dosing rack B 23 is arranged inside the stirring cylinder 2; a filtering mechanism, the filtering mechanism includes a filter 7 provided below the stirring cylinder 2. An outlet pipe 6 is provided between the stirring barrel and the filter 7. The filter 7 includes a filter cover body 28 connected to the outlet pipe 6. A drum 29 is provided below the filter cover body 28. The lower end of the drum 29 is connected to a drum motor 27. A filter grate 31 is provided outside the drum motor 27. The filter grate 31 is fixedly connected to the shell of the filter 7. A material receiving bucket 12 is provided below the filter 7.

[0038] In this embodiment, the mixing drum 2 is horizontal and is fixed to the support 1 at both ends through a tripod. A cover body 20 is provided at one end of the mixing drum 2, a bearing 21 is provided on the cover body 20, and a mixing shaft 17 is installed on the bearing 21. The end of the mixing shaft 17 is connected to a mixing motor 3, and the mixing motor 3 is fixed to the support 1. Mixing arms 18 are provided on the mixing shaft 17, and the mixing arms 18 facilitate the mixing of lactic acid. The dosing mechanism is used to supply the flocculant. The flocculant is contained in the dosing tank 14 and is provided into the mixing drum 2 under the action of the pump body 8. Since the mixing shaft 17 has a certain length, if it is directly poured into the mixing drum 2 through an external connection, it is not easy to evenly distribute the flocculant in the mixing drum 2. Therefore, by providing the dosing mechanism, the flocculant can be quickly and evenly distributed in the mixing drum 2. After a certain period of treatment with the flocculant, the impurities can solidify and crystallize, and then are filtered by the drum 29 of the filter 7 to obtain purified lactic acid, and then the lactic acid enters the material storage bucket 12.

[0039] The mixing shaft 17 is of a hollow structure, one end is connected to the mixing motor 3, a bearing 21 is provided on the mixing shaft 17, and the cover body 20 is connected through the bearing 21. The cover body 20 and the mixing drum 2 are fixedly connected, and the mixing drum 2 and the support 1 are fixedly connected. The mixing arm 18 is of a round rod structure and is fixed to the mixing shaft 17.

[0040] In this embodiment, the mixing shaft 17 is of a hollow structure, and pipelines are provided inside for the flocculant to pass through. The mixing shaft 17 is connected to a bearing 21, and the bearing 21 is installed on the cover body 20.

[0041] A support plate 13 is provided on the support 1. The pump body 8 and the dosing tank 14 are fixed on the support plate 13. The pump body 8 is connected to the dosing tank 14 through a pipeline. The output end of the pump body 8 is connected to a dosing pipe A9 and a dosing pipe B10. A dosing inlet A25 is provided on the rotary joint A15, and a dosing inlet B26 is provided on the rotary joint B16. The dosing inlet A25 is connected to a dosing rack A19 through a pipeline provided inside the mixing shaft 17, and the dosing inlet B26 is connected to a dosing rack B23 through a pipeline provided inside the mixing shaft 17.

[0042] In this embodiment, a support plate 13 is provided. The pump body 8 and the dosing tank 14 are installed on the support plate 13. The output end of the pump body 8 is connected to a dosing pipe A9 and a dosing pipe B10. The other end of the dosing pipe A9 is connected to a dosing inlet A25, and the dosing inlet A25 communicates with the rotary joint A15. The rotary joint A15 and the mixing shaft 17 are rotatably connected, and the rotary joint B16 and the mixing shaft 17 are also rotatably connected. Specifically, two grooves are provided on the mixing shaft 17, and the dosing inlet A25 and the dosing inlet B26 are provided on the grooves.

[0043] The agent supply rack A19 is a hollow round rod structure, with an agent supply outlet A22 provided on the outer side surface. The agent supply rack A19 is parallel to the stirring shaft 17. The agent supply rack B23 is a hollow round rod structure, with an agent supply outlet B24 provided on the outer side surface. The agent supply rack B23 is parallel to the stirring shaft 17. The agent supply rack A19 is distributed in the front part of the stirring shaft 17, and the agent supply rack B23 is distributed in the rear part of the stirring shaft 17, for evenly dispersing the flocculant in the stirring cylinder 2.

[0044] In this embodiment, the agent supply rack A19 and the agent supply rack B23 need to be arranged along the stirring shaft 17, and are arranged on the front part and the rear part of the stirring shaft 17, which can not only achieve the stirring effect but also release the flocculant.

[0045] The filter 7 is a hollow shell structure, with a stabilizing frame 11 fixedly connected to the outside. The upper end of the filter 7 is a filter cover body 28. The filter cover body 28 is fixedly connected and communicated with the discharge pipe 6, and a valve is provided on the discharge pipe 6.

[0046] In this embodiment, the stabilizing frame 11 is used to fix the filter 7. A filter cover body 28 is provided at the top of the filter 7, and a valve for cutting off is provided on the discharge pipe 6.

[0047] The filter grate 31 is provided with leakage holes, and the leakage holes are evenly distributed on the outside of the drum 29. The outer side surface of the filter grate 31 is fixedly connected to the shell of the filter 7. The drum motor 27 is fixedly connected to the filter grate 31, and the output end of the drum motor 27 is connected to the drum 29 and drives the drum 29 to rotate.

[0048] In this embodiment, the drum 29 rotates driven by the drum motor 27, which can not only improve the filtration but also reduce the accumulation of flocculent impurities.

[0049] The working method (or working principle) of the present invention:

[0050] When this technology is working, Step 1: Heating, heating the depolymerized lactic acid.

[0051] Step 2: Adding the flocculant. After rising to a certain temperature, weigh the flocculant according to the addition ratio of lactic acid to the flocculant, and add it to the heated lactic acid.

[0052] Step 3: Stirring and heat preservation. After adding the flocculant, stir until the flocculant is dissolved, and stop stirring and start timing for heat preservation.

[0053] Step 4: Precoating, precoating the filter 7 with the prepared perlite or diatomaceous earth.

[0054] Step 5: Filtration. After the heat preservation ends, filter while it is hot.

[0055] Step 6: Measure the lactic acid content and viscosity. Take the lactic acid before and after impurity removal to measure its lactic acid content and viscosity, record and calculate the lactic acid loss rate. It is necessary to heat the lactic acid to 70 - 90 °C; the flocculant used is polyacrylamide; the stirring rate after adding the flocculant is 30 - 50 HZ; the feeding ratio of lactic acid to the flocculant is 1000:0.5 - 1000:1.5; after the flocculant is dissolved, keep warm for 1 - 2 h; the precoating agent used for precoating is perlite or diatomite.

[0056] In the present invention, unless otherwise clearly specified and defined, for example, it can be fixedly connected, can also be detachably connected, or integrated; it can be mechanically connected, can also be electrically connected; it can be directly connected, can also be indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components. Unless otherwise clearly defined, for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0057] The above is the preferred implementation manner of the present invention. It should be pointed out that for those of ordinary skill in the technical field, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A lactic acid purification device, comprising a bracket (1) and a stirring cylinder (2) arranged on the bracket (1), the stirring cylinder (2) being connected to a stirring motor (3) fixed on the bracket (1), characterized in that: It further includes a stirring mechanism, which includes a stirring shaft (17) connected to the output end of a stirring motor (3). The stirring shaft (17) extends into a stirring cylinder (2), and stirring arms (18) are arranged on the stirring shaft (17); a dosing mechanism, which includes a pump body (8) arranged on a bracket (1). The pump body (8) is connected to a dosing tank (14) arranged on the bracket (1). The pump body (8) is connected to a rotary joint through a pipeline. The rotary joint includes a rotary joint A (15) and a rotary joint B (16). The rotary joint A (15) is connected to a dosing pipe A (9), and the dosing pipe A (9) is connected to a dosing rack A (19). The dosing rack A (19) is fixed on the stirring shaft (17) and is arranged inside the stirring cylinder (2). The rotary joint B (16) is connected to a dosing pipe B (10), and the dosing pipe B (10) is connected to a dosing rack B (23). The dosing rack B (23) is arranged on the stirring shaft (17) and is arranged inside the stirring cylinder (2); a filtering mechanism, which includes a filter (7) arranged below the stirring cylinder (2). An outlet pipe (6) is arranged between the stirring barrel and the filter (7). The filter (7) includes a filter cover body (28) connected to the outlet pipe (6). A roller (29) is arranged below the filter cover body (28). The lower end of the roller (29) is connected to a roller motor (27). A filter grate (31) is arranged outside the roller motor (27). The filter grate (31) is fixedly connected to the shell of the filter (7). A material receiving bucket (12) is arranged below the filter (7).

2. The lactic acid purification device according to claim 1, wherein: The stirring shaft (17) is of a hollow structure and is connected to the stirring motor (3) at one end. Bearings (21) are arranged on the stirring shaft (17), and a cover body (20) is connected through the bearings (21). The cover body (20) is fixedly connected to the stirring cylinder (2), and the stirring cylinder (2) is fixedly connected to the bracket (1). The stirring arms (18) are of a round rod structure and are fixed on the stirring shaft (17).

3. The lactic acid purification device according to claim 2, characterized in that: A support plate (13) is arranged on the bracket (1). The pump body (8) and the dosing tank (14) are fixed on the support plate (13). The pump body (8) is connected to the dosing tank (14) through a pipeline. The output end of the pump body (8) is connected to the dosing pipe A (9) and the dosing pipe B (10). A dosing inlet A (25) is arranged on the rotary joint A (15), and a dosing inlet B (26) is arranged on the rotary joint B (16). The dosing inlet A (25) is connected to the dosing rack A (19) through a pipeline arranged inside the stirring shaft (17), and the dosing inlet B (26) is connected to the dosing rack B (23) through a pipeline arranged inside the stirring shaft (17).

4. The lactic acid purification device according to claim 3, characterized in that: The reagent supply rack A (19) is of a hollow round rod structure, and a reagent supply outlet A (22) is arranged on the outer side surface. The reagent supply rack A (19) is parallel to the stirring shaft (17). The reagent supply rack B (23) is of a hollow round rod structure, and a reagent supply outlet B (24) is arranged on the outer side surface. The reagent supply rack B (23) is parallel to the stirring shaft (17). The reagent supply rack A (19) is distributed in the front of the stirring shaft (17), and the reagent supply rack B (23) is distributed in the rear of the stirring shaft (17), which is used to evenly disperse the flocculant in the stirring cylinder (2).

5. The lactic acid purification device according to claim 4, characterized in that: The filter (7) is of a hollow shell structure, and a stabilizing frame (11) is fixedly connected to the outside. The upper end of the filter (7) is a filter cover body (28). The filter cover body (28) is fixedly connected and communicated with the discharge pipe (6). A valve is arranged on the discharge pipe (6).

6. The lactic acid purification device according to claim 5, wherein: The filter grate (31) is provided with leakage holes, and the leakage holes are evenly distributed on the outer side of the drum (29). The outer side surface of the filter grate (31) is fixedly connected to the shell of the filter (7). The drum motor (27) is fixedly connected to the filter grate (31), and the output end of the drum motor (27) is connected to the drum (29) and drives the drum (29) to rotate.

7. A method for lactic acid purification, characterized in that: Including the purification device according to any one of the above claims 1-6, the following steps are carried out: Step 1: Heating, heating the depolymerized lactic acid. Step 2: Adding the flocculant. After rising to a certain temperature, weigh the flocculant according to the addition ratio of lactic acid to the flocculant, and add it to the heated lactic acid. Step 3: Stirring and heat preservation. After adding the flocculant, stir until the flocculant is dissolved, stop stirring and start timing for heat preservation. Step 4: Precoating, precoating the filter (7) with the prepared perlite or diatomite. Step 5: Filtration. After the heat preservation ends, filter while it is hot. Step 6: Measuring the lactic acid content and viscosity. Take the lactic acid before and after impurity removal to measure its lactic acid content and viscosity, record and calculate the lactic acid loss rate.

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