Equipment for recycling accelerant through back extraction
By designing a reverse extraction and recycling equipment that utilizes countercurrent contacts, liquid distributors and baffles, the loss problem of rubber vulcanization accelerator MBT in toluene extract is solved, and the effect of improving production efficiency and product quality is achieved.
Patent Information
- Application Number
- CN202421300964.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-07
- Publication Date
- 2025-03-07
- Estimated Expiration
- 2034-06-07
AI Technical Summary
During the production process of the rubber vulcanization accelerator MBT, part of the MBT is dissolved into the toluene solvent, resulting in product losses, increased production costs and fluctuations in product quality.
A equipment for strip extraction and recovery accelerator is designed to enhance the mixing degree and reaction efficiency between the solutions by taking advantage of the insolubleness of toluene and alkali liquid and the density difference is large.
It effectively reduces the loss of MBT, improves production efficiency and product quality, reduces production costs, and improves the safety of equipment.
Smart Images
Figure CN222566875U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of equipment for recycling a rubber vulcanization accelerator MBT, in particular to equipment for recycling an accelerator through back extraction. Background Art
[0002] In the production process of rubber vulcanization accelerator MBT, it is now common to purify the synthesized MBT by extraction with toluene solvent, and at the same time dissolve the resin by-products in toluene solvent to finally obtain qualified MBT products.
[0003] During the extraction process, part of the promoter MBT will dissolve into the toluene solvent, which means that part of the MBT that could have become a qualified product is taken away, resulting in product loss and increased production costs. Since part of the MBT dissolves into the toluene solvent, it will cause fluctuations in product quality and affect the stability and consistency of the product. Therefore, measures need to be taken during the production process to minimize this product loss and improve production efficiency and product quality. Utility Model Content
[0004] 1) Technical issues solved
[0005] The utility model provides a device for recovering an accelerator by back extraction, so as to solve the problem that part of the existing rubber vulcanization accelerator MBT is lost in a toluene extract.
[0006] 2) Technical solution
[0007] To achieve the above object, the utility model provides the following technical solution: a device for stripping and recovering a promoter, comprising a reaction tower, wherein the top of the reaction tower is connected to a first liquid inlet pipe and a first liquid outlet pipe, and the bottom of the reaction tower is connected to a second liquid inlet pipe and a second liquid outlet pipe, comprising:
[0008] a first liquid distributor and a second liquid distributor, wherein the first liquid distributor is close to the first liquid inlet pipe and is located below the first liquid inlet pipe, and the second liquid distributor is close to the second liquid inlet pipe and is located above the second liquid inlet pipe; and
[0009] A plurality of baffles are located between the first liquid distributor and the second liquid distributor, and the baffles are used to change the flow direction of the liquid, and any two adjacent baffles change the flow direction of the liquid in opposite directions.
[0010] Furthermore, the support plates in the baffles are connected to the inner wall of the reaction tower, and any two adjacent support plates are spaced a certain distance apart in a direction perpendicular to the horizontal plane.
[0011] Furthermore, the diverter mesh plate in the baffle is located at the edge of the baffle; in any two adjacent diverter mesh plates, the distance between each diverter mesh plate and the central axis of the reaction tower is the same.
[0012] Furthermore, the baffle includes a plurality of guide plates arranged in a direction perpendicular to the diversion mesh plate.
[0013] Further, the guide plate includes a first guide plate and a second guide plate, wherein:
[0014] The first guide plate is perpendicular to the flow dividing mesh plate;
[0015] The plurality of second guide plates are symmetrically distributed relative to the first guide plate, and each second guide plate is located at one end away from the flow dividing mesh plate and is inclined close to the first guide plate.
[0016] Furthermore, the density of the liquid transported by the first liquid inlet pipe is greater than the density of the liquid transported by the second liquid inlet pipe.
[0017] Furthermore, the density of the liquid output by the second liquid outlet pipe is greater than the density of the liquid output by the first liquid outlet pipe.
[0018] 3) Beneficial effects:
[0019] Compared with the prior art, the utility model has the following beneficial effects:
[0020] The utility model utilizes the characteristics that toluene and alkali solution in toluene mother solution are immiscible and have a large density difference. Alkaline solution is passed from the top of a reaction tower and toluene mother solution is passed from the bottom of the reaction tower. The two material solutions are naturally countercurrently contacted in the reaction tower. A liquid distributor and a baffle are arranged inside the reaction tower to increase the mixing degree between the solutions, thereby enhancing mass transfer and reaction efficiency in the reaction process. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Figure 1 A front cross-sectional schematic diagram of a stripping recovery device provided in an embodiment of the present application;
[0022] Figure 2 A schematic top view and cross-sectional view of a baffle in a stripping recovery device provided in an embodiment of the present application;
[0023] Figure 3 This is a schematic diagram of introducing toluene mother liquor and alkali solution into a stripping recovery device provided in an embodiment of the present application, contacting and separating them inside the device, and recovering toluene from a liquid outlet pipe. DETAILED DESCRIPTION
[0024] The technical solutions in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the utility model.
[0025] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0026] In the existing production, extraction and purification process of the rubber vulcanization accelerator MBT, the rubber vulcanization accelerator MBT is first synthesized to obtain a crude product, and the synthesized MBT crude product is put into an extraction kettle. Under certain temperature and stirring conditions, the resin by-products are dissolved in the toluene solvent. After extraction, the toluene extraction mother liquor containing the dissolved resin is extracted through a suction filtration tank, thereby separating and extracting the target product.
[0027] After the above treatment, a qualified rubber vulcanization accelerator MBT product is obtained. At the same time, the toluene extraction mother liquor is distilled to recover toluene for recycling, and the distillation residue is treated as hazardous waste.
[0028] The extracted MBT meets the product quality requirements. During the extraction, in order to allow the by-products to be fully dissolved in the toluene solvent and make MBT meet the qualified requirements, a certain temperature must be maintained. However, 5% of the promoter MBT output will be dissolved in the toluene solvent. 5% of the promoter MBT dissolved in the toluene solvent means that a part of the MBT that could have become a qualified product is taken away, resulting in product loss. Product loss will lead to an increase in production costs because more raw materials are needed to make up for the loss. Since part of the MBT is dissolved in the toluene solvent, it will cause fluctuations in product quality, affecting the stability and consistency of the product, thereby affecting the performance and reliability of the final product.
[0029] In addition, the existing extraction device is provided with a rotating and power component, and the rotating power device is used to stir and promote the contact of the materials, so that the extraction reaction can be carried out more thoroughly. However, the rotating component will cause certain sealing problems, thereby causing the leakage of alkali solution and toluene mother liquor.
[0030] Furthermore, in order to improve the defects in the above-mentioned prior art, an equipment for stripping and recovering the accelerator is proposed in the embodiment of the present application. The equipment utilizes the principle that alkali solution and toluene are immiscible and the large density difference between the two to reduce the loss of the rubber vulcanization accelerator MBT and improve safety by means of solution countercurrent stripping.
[0031] First, the present application embodiment provides a device for stripping and recovering a promoter, combined with Figures 1 to 3 As shown, a reaction tower 1 for stripping operation is included, wherein the top of the reaction tower 1 is connected to a first liquid inlet pipe 4 and a first liquid outlet pipe 2, and the bottom of the reaction tower 1 is connected to a second liquid inlet pipe 5 and a second liquid outlet pipe 3, wherein the first liquid inlet pipe 4 located at the top of the reaction tower 1 is used to introduce an alkali solution with a relatively high density, and the second liquid inlet pipe 5 located at the bottom of the reaction tower 1 is used to introduce a toluene mother liquor with a relatively low density. In a feasible embodiment, the first liquid inlet pipe 4 located at the top introduces a sodium hydroxide solution (with a sodium hydroxide content of 32% and a density of 1.349 g / ml at 20°C), and the second liquid inlet pipe 5 located at the bottom introduces a toluene mother liquor (with a toluene density of 0.87 g / ml at 20°C, containing MBT), the toluene mother liquor floats upward, and the alkali solution sinks downward, and the two are contacted in countercurrent to carry out the following reaction inside the reaction tower 1:
[0032] MBT reacts with sodium hydroxide to form M-Na salt:
[0033]
[0034] M-Na salt reacts with sulfuric acid to generate promoter MBT:
[0035]
[0036] Combination Figure 3 As shown, the reaction products are immiscible with each other and have density differences, so the inside of the reaction tower 1 is mainly divided into three liquid sections, among which the liquid section located at the top of the reaction tower 1 is the light liquid separation section, the liquid section located at the bottom of the reaction tower 1 is the heavy liquid separation section, and the liquid section located in the middle of the reaction tower 1 is a mixed reaction section between the density differences of the two.
[0037] More specifically, in combination with the above reaction formula, it can be known that the light liquid section located at the top of the reaction tower 1 is the toluene mother liquor, and the heavy liquid section located at the bottom of the reaction tower 1 is the M-Na solution.
[0038] In combination with the above, it can be understood that the second liquid outlet pipe 3 located at the bottom of the reaction tower 1 outputs the M-Na solution with a higher density, and the first liquid outlet pipe 2 located at the top of the reaction tower 1 outputs the toluene mother liquor with a lower density.
[0039] Furthermore, considering how to enable the toluene mother liquor and the alkali solution to fully contact and react through countercurrent contact, the embodiments provided in the present application specifically provide a device that enables the toluene mother liquor and the alkali solution to fully contact and react.
[0040] Specifically, Figures 1 to 3 As shown, inside the reaction tower 1, near the position of the first liquid inlet pipe 4, a first liquid distributor 6 is installed below the first liquid inlet pipe 4. In some feasible embodiments, the first liquid inlet pipe 4 passes sodium hydroxide solution into the interior of the reaction tower 1. Through the first liquid distributor 6, the sodium hydroxide can flow to the bottom of the reaction tower 1 in a uniform manner to avoid excessive or insufficient local liquid phase, thereby improving the reaction efficiency and product quality.
[0041] In the same way, inside the reaction tower 1, near the second liquid inlet pipe 5, a second liquid distributor 7 is installed above the second liquid inlet pipe 5. Toluene mother liquor (containing MBT) is passed through the second liquid inlet pipe 5 into the reaction tower 1. Through the second liquid distributor 7, it is ensured that the toluene mother liquor can flow evenly to the upper part of the reaction tower 1 to contact and react with the sodium hydroxide solution, avoiding excessive or insufficient local liquid phase, and ensuring sufficient contact and reaction of the reaction materials.
[0042] The first liquid distributor 6 and the second liquid distributor 7 may be, but are not limited to, a trough-type liquid distributor, a tubular liquid distributor, a bidirectional cyclone, a bidirectional distribution plate, a porous distribution plate, and the like.
[0043] On the basis of ensuring that the toluene mother liquor and the sodium hydroxide solution are evenly distributed in the reaction tower 1, in some feasible embodiments provided in the present application, Figures 1 to 3 As shown, inside the reaction tower 1, between the first liquid distributor 6 and the second liquid distributor 7, a plurality of baffles are evenly installed from top to bottom, and the baffles are used to change the flow direction of the liquid, and any two adjacent baffles change the flow direction of the liquid in opposite directions. This design is to increase the contact surface area between the liquids, which can further increase the degree of mixing, promote reaction efficiency and mixing, and help improve the mixing and mass transfer effects inside the reaction tower 1, thereby enhancing the mass transfer and reaction efficiency during the reaction process.
[0044] Specifically, in an embodiment of the present application, a device for back-extraction and recovery of a promoter is provided, in which the structure and composition of the baffles mentioned above are further limited.
[0045] refer to Figure 2, is a top view schematic cross-sectional view of a baffle in the stripping recovery equipment provided in an embodiment of the present application, wherein the baffle includes a support plate 8, a diverter mesh plate 9 and a guide plate 10. Wherein: the support plate 8 is used to provide structural support and stability to ensure that the baffle is firmly positioned inside the reaction tower 1, and the support plate 8 is usually made of a solid material to withstand the pressure and force brought by the flow of liquid. The diverter mesh plate 9 is designed to have a hole or grid structure, which is used to disperse and diffuse the liquid when the liquid flows through to increase the surface area and mixing effect. The diverter mesh plate 9 helps to break the uniformity of the liquid flow and promote the contact and mass transfer between the liquid and the gas. The guide plate 10 is designed to guide the liquid flow and change the flow direction to ensure that the liquid is evenly distributed and mixed inside the reaction tower 1. The provision of the guide plate 10 can effectively increase the movement path of the liquid and promote the mixing and mass transfer process.
[0046] Based on the above structure, refer to Figures 1 to 3 , from top to bottom, the support plates 8 in the baffles are connected to the inner wall of the reaction tower 1, and any two adjacent support plates 8 are spaced a certain distance apart in a direction perpendicular to the horizontal plane. In some feasible embodiments, a plurality of support plates 8 are fixedly installed on the inner wall of the reaction tower 1 in a staggered manner, that is, in the installation area of the plurality of support plates 8, the solution in the reaction tower 1 changes its flow path multiple times.
[0047] It is understandable that by connecting the support plates 8 to the inner wall of the reaction tower 1 and staggering adjacent support plates 8 in the vertical direction, more liquid flow channels can be created, so that the liquid can be better mixed and diffused inside the reaction tower 1. This design helps to increase the contact surface area between different solutions, improve reaction efficiency and mass transfer performance. The staggered arrangement of the support plates 8 can further optimize the flow path of the liquid, avoid the formation of dead corners or areas with poor flow of the liquid inside the reaction tower 1, and ensure that the liquid is evenly distributed and mixed throughout the reaction tower 1.
[0048] Furthermore, the diverter mesh plate 9 in each of the baffles is located at the edge of the baffle; in any two adjacent diverter mesh plates 9, the distance between each diverter mesh plate 9 and the central axis of the reaction tower 1 is the same, that is, the flow of the liquid on different baffles is relatively uniform.
[0049] It is understandable that placing the diverter mesh 9 at the edge of the baffle can effectively diffuse and disperse the liquid flow and increase the contact surface area between different liquids. This arrangement helps to effectively promote mixing and mass transfer when the liquid flows through the baffle, thereby improving the efficiency and performance inside the reaction tower 1. Ensuring that each diverter mesh 9 is at the same distance from the center axis of the reaction tower 1 can further optimize the uniformity and stability of the liquid flow. This design can ensure that the flow path of the liquid is relatively uniform, avoiding poor flow or insufficient local mixing, thereby improving the mixing effect and reaction efficiency inside the reaction tower 1.
[0050] On the basis of the above structure, the baffle includes a plurality of guide plates 10 arranged in a direction perpendicular to the diverter mesh plate 9. The guide plates 10 include a first guide plate 10a and a second guide plate 10b, wherein the first guide plate 10a is perpendicular to the diverter mesh plate 9; the plurality of second guide plates 10b are symmetrically distributed relative to the first guide plate 10a, and each second guide plate 10b is away from one end of the diverter mesh plate 9 and is inclined close to the first guide plate 10a. The first guide plate 10a and the plurality of guide plates 10 are used to guide the flow direction of the liquid and promote mixing between different liquids.
[0051] It is understandable that the first guide plate 10a is perpendicular to the diverter mesh plate 9, which can guide the liquid flow and change the flow direction to promote the mixing and diffusion of the liquid. The symmetrical distribution and inclined setting of the second guide plate 10b helps to further diffuse and disperse the liquid flow and increase the mixing effect inside the reaction tower 1.
[0052] In an embodiment of the present application, a sodium hydroxide solution is passed into the reaction tower 1 through a first liquid inlet pipe 4, and a toluene mother liquor is passed into the reaction tower 1 through a second liquid inlet pipe 5. The toluene mother liquor and the sodium hydroxide solution are in countercurrent contact in a stripping device, and are fully contacted and reacted through a liquid distributor and a plurality of baffles, so that the MBT in the toluene mother liquor and the sodium hydroxide are fully reacted. After the reaction is completed, the liquid in the stripping device is layered into three sections. The M-Na liquid is located below the reaction tower 1, and the M-Na liquid is output through the second liquid outlet pipe 3 and then neutralized to recover the MBT. The toluene mother liquor is located above the reaction tower 1, and the toluene mother liquor is output through the first liquid outlet pipe 2 and then distilled to recover the toluene.
[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the description and drawings of the present invention shall be included in the protection scope of the present invention.
Claims
1. A device for stripping and recovering a promoter, comprising a reaction tower (1), wherein the top of the reaction tower (1) is connected to a first liquid inlet pipe (4) and a first liquid outlet pipe (2), and the bottom of the reaction tower (1) is connected to a second liquid inlet pipe (5) and a second liquid outlet pipe (3), characterized in that: include: A first liquid distributor (6) and a second liquid distributor (7), wherein the first liquid distributor (6) is close to the first liquid inlet pipe (4) and is located below the first liquid inlet pipe (4), and the second liquid distributor (7) is close to the second liquid inlet pipe (5) and is located above the second liquid inlet pipe (5); and a plurality of baffles are located between the first liquid distributor (6) and the second liquid distributor (7), wherein the baffles are used to change the flow direction of the liquid, and any two adjacent baffles change the flow direction of the liquid in opposite directions.
2. The device for stripping and recovering a promoter according to claim 1, characterized in that: The support plates (8) in the baffles are connected to the inner wall of the reaction tower (1), and any two adjacent support plates (8) are spaced a certain distance apart in a direction perpendicular to the horizontal plane.
3. The device for stripping and recovering a promoter according to claim 2, characterized in that: The flow dividing mesh plate (9) in the baffle is located at the edge of the baffle; in any two adjacent flow dividing mesh plates (9), the distance between each flow dividing mesh plate (9) and the central axis of the reaction tower (1) is the same.
4. The device for stripping and recovering a promoter according to claim 3, characterized in that: The baffle plate comprises a plurality of guide plates (10) arranged in a direction perpendicular to the flow dividing mesh plate (9).
5. The device for stripping and recovering a promoter according to claim 4, characterized in that: The guide plate (10) comprises a first guide plate (10a) and a second guide plate (10b), wherein: The first guide plate (10a) is perpendicular to the flow dividing mesh plate (9); The plurality of second guide plates (10b) are symmetrically distributed relative to the first guide plate (10a), and each second guide plate (10b) is located away from one end of the flow dividing mesh plate (9) and is inclined toward the first guide plate (10a).
6. The device for stripping and recovering a promoter according to claim 1, characterized in that: The density of the liquid transported by the first liquid inlet pipe (4) is greater than the density of the liquid transported by the second liquid inlet pipe (5).
7. The device for stripping and recovering a promoter according to claim 1, characterized in that: The density of the liquid output by the second liquid outlet pipe (3) is greater than the density of the liquid output by the first liquid outlet pipe (2).