Recycling system for low-solid-content low-boiling-point coating water-based colored paint waste solvent

Abstract

The utility model discloses a recycling system for a low-solid-content low-boiling-point coating water-based colored paint waste solvent, which comprises a flocculation unit, an adsorption unit and a rectification unit, the flocculation unit comprises a reaction kettle, a filter and a clear liquid tank A for collecting filtered clear liquid, and the adsorption unit comprises an adsorption tower. The rectification unit comprises a clear liquid tank B for receiving the clear liquid treated by the adsorption tower, meanwhile, a clear liquid material is taken as a raw material and enters a rectification device for separation and purification treatment, a purified recovery solvent is extracted from the tower top as a product, and a concentrated solution in a tower kettle continuously enters a colored paint waste solvent storage tank. The utility model relates to the technical field of vehicle waste solvent treatment. According to the recycling system for the low-solid-content and low-boiling-point coating water-based colored paint waste solvent, the rectification unit is used for replacing an existing membrane separation unit, and the recycling system is more effective for recycling the low-solid-content and low-boiling-point coating water-based colored paint waste solvent.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicle waste solvent treatment, in particular to a recycling and reuse system for waste solvents of low-solid-content and low-boiling-point water-based paint. Background Art

[0002] After searching, Chinese patent CN212357112U discloses a system for recycling waste solvents from water-based paint, including a flocculation unit, an adsorption unit, and a membrane separation unit. The flocculation unit includes a reactor for reacting the waste solvent of the paint with an aqueous solution of a flocculant, a filter for filtering the reaction product in the reactor, and a clear liquid tank for collecting the clear liquid after filtration. The adsorption unit includes a primary adsorption tower and a secondary adsorption tower for sequentially adsorbing the clear liquid in the clear liquid tank. The membrane separation unit includes a mother liquid tank for storing mother liquid and a membrane separation device for filtering the mother liquid in the mother liquid tank. The filtrate filtered by the membrane separation device is extracted as a recovered solvent. The recovery rate of effective components in the waste solvent of the paint of the utility model is ≥85%, and the reduction of hazardous waste is ≥85%.

[0003] As described above, the current recycling and reuse system for waste solvents from water-based paints uses a membrane separation unit to recover effective cleaning components in waste solvents from paints, thereby reducing hazardous waste, reducing the cost of hazardous waste treatment for enterprises and reducing the cost of cleaning agent raw materials, while ensuring that the recycling process is green and environmentally friendly. Waste solvents of different components have their own characteristics and physical properties. For waste solvents with low solid content (absolute dry solid content within 3%) and conventional solvents (low boiling point) as solvent components, the waste solvents have low boiling point characteristics. During the membrane separation process, the solvent may evaporate due to increased temperature, thereby affecting the effect of membrane separation. Evaporation may not only cause solvent loss, but also damage the separation membrane. In addition, low solid content means that the waste solvent contains a large amount of solvent components, and membrane separation technology is usually more effective for treating mixtures with high concentrations or high solid content. In the case of low solid content, membrane separation may be difficult to effectively separate the target component from the solvent. To this end, the applicant has designed a recycling and reuse system for waste solvents from water-based paints with low solid content and low boiling point to solve the above problems. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides a system for recycling and reusing waste solvents from water-based paints with low solid content and low boiling point, which solves the problem that the membrane separation unit of the current system for recycling and reusing waste solvents from water-based paints is not suitable for treating waste solvents from paints with low solid content and low boiling point as solvent components.

[0005] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] The recycling and reuse system of the waste solvent of low-solid-content and low-boiling-point water-based paint is suitable for waste solvent of paint with low solid content (absolute dry solid content within 3%wt) and conventional solvent (low boiling point) as the solvent component.

[0007] The recycling and reuse system of waste solvent of low-solid-content and low-boiling-point water-based paint comprises a flocculation unit, an adsorption unit and a distillation unit;

[0008] The flocculation unit includes a reactor R101 for stirring the added paint waste solvent and the flocculant aqueous solution, a filter F101 for filtering the suspension formed by the reaction in the reactor R101, and a clear liquid tank AV101 for collecting the clear liquid after filtration;

[0009] The adsorption unit includes an adsorption tower T101, which is used to perform adsorption and decolorization treatment on the clear liquid in the clear liquid tank AV101;

[0010] The distillation unit includes a clear liquid tank BV102 for receiving the clear liquid after treatment by the adsorption tower T101. At the same time, the clear liquid material is taken as a raw material into the distillation device D101 for separation and purification. The purified recovered solvent is extracted from the top of the tower as a product and the concentrated liquid in the bottom of the tower continues to enter the paint waste solvent storage tank for subsequent recycling treatment.

[0011] The flocculation unit further includes a suspension delivery pump P101 for delivering the suspension in the reactor R101 to the filter F101.

[0012] The adsorption unit further comprises a clear liquid delivery pump AP102 for delivering the clear liquid in the clear liquid tank AV101 to the adsorption tower T101.

[0013] The distillation unit further comprises a clear liquid delivery pump BP103, which is used to deliver the clear liquid in the clear liquid tank BV102 as a raw material to the distillation device D101.

[0014] Wherein, the adsorption tower T101 is filled with activated carbon or ion exchange resin.

[0015] Wherein, the distillation device D101 adopts a packed tower method, and the operating pressure is 5kPa-70kPa.

[0016] The utility model discloses a system for recycling and reusing waste solvents of water-based paints with low solid content and low boiling point, which replaces the existing membrane separation unit with a distillation unit. The system is more effective in recycling waste solvents of water-based paints with low solid content and low boiling point. Meanwhile, the flocculation-distillation system has a relatively simple structure and low maintenance cost.

[0017] It has been determined that the system for recycling and reusing waste solvents of water-based paints with low solid content and low boiling point of the utility model has a recovery rate of effective components in the waste solvents of the paint of ≥85%, and a reduction in hazardous waste of ≥85%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a system structure diagram of the utility model;

[0019] In the figure: R101, reactor; P101, suspension delivery pump; F101, filter; V101, clear liquid tank A; P102, clear liquid delivery pump A; T101, adsorption tower; V102, clear liquid tank B; P103, clear liquid delivery pump B; D101, distillation device. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] See also Figure 1 , the utility model provides a technical solution: a recycling and reuse system for waste solvents of low-solid content and low-boiling point water-based paint, comprising a flocculation unit, an adsorption unit, and a distillation unit;

[0022] The flocculation unit includes a reactor R101 for stirring the added paint waste solvent and the flocculant aqueous solution, a filter F101 for filtering the suspension formed by the reaction in the reactor R101, and a clear liquid tank AV101 for collecting the clear liquid after filtration;

[0023] The adsorption unit includes an adsorption tower T101, which is used to perform adsorption and decolorization treatment on the clear liquid in the clear liquid tank AV101;

[0024] The distillation unit includes a clear liquid tank BV102 for receiving the clear liquid after treatment by the adsorption tower T101. At the same time, the clear liquid material is taken as a raw material into the distillation device D101 for separation and purification. The purified recovered solvent is extracted from the top of the tower as a product and the concentrated liquid in the bottom of the tower continues to enter the paint waste solvent storage tank for subsequent recycling treatment.

[0025] The flocculation unit further includes a suspension delivery pump P101 for delivering the suspension in the reactor R101 to the filter F101.

[0026] The adsorption unit further comprises a clear liquid delivery pump AP102 for delivering the clear liquid in the clear liquid tank AV101 to the adsorption tower T101.

[0027] The distillation unit further comprises a clear liquid delivery pump BP103, which is used to deliver the clear liquid in the clear liquid tank BV102 as a raw material to the distillation device D101.

[0028] Wherein, the adsorption tower T101 is filled with activated carbon or ion exchange resin.

[0029] Wherein, the distillation device D101 adopts a packed tower method, and the operating pressure is 5kPa-70kPa.

[0030] Among them, the reactor R101 is provided with a raw material inlet, a flocculant inlet, a material outlet and a material return port, wherein the material outlet is connected to the material inlet of the suspension delivery pump P101, and the material return port is connected to the material outlet of the suspension delivery pump P101. The suspension delivery pump P101 is provided with a material inlet and a material outlet, wherein the material inlet is connected to the material outlet of the reactor R101, and the material outlet is divided into two routes, one is connected to the material return port of the reactor R101, and the other is connected to the filter F101. The filter F101 is provided with a material inlet, a solid product outlet and a liquid product outlet, wherein the material inlet is connected to the suspension delivery pump P101, the solid product outlet is used to extract solid waste, and the liquid product outlet is connected to the clear liquid tank AV101.

[0031] The clear liquid tank AV101 is provided with a material inlet and a material outlet, wherein the material inlet is connected to the liquid product outlet of the filter F101, and the material outlet is connected to the clear liquid delivery pump AP102, and the clear liquid delivery pump AP102 is provided with a material inlet and a material outlet, wherein the material inlet is connected to the clear liquid tank AV101, and the material outlet is connected to the adsorption tower T101, and the adsorption tower T101 is provided with a material inlet and a material outlet, wherein the material inlet is connected to the clear liquid delivery pump AP102, and the material outlet is connected to the clear liquid tank BV102, and the clear liquid tank BV102 is provided with a material inlet and a material outlet Inlet, wherein the material inlet is connected to the material outlet of the adsorption tower T101, and the material outlet is connected to the material inlet of the clear liquid delivery pump BP103; the clear liquid delivery pump BP103 is provided with a material inlet and a material outlet, wherein the material inlet is connected to the clear liquid tank BV102, and the material outlet is connected to the distillation device D101, the distillation device D101 is provided with a material inlet, a concentrated liquid outlet is provided at the bottom of the tower, and a product outlet is provided at the top of the tower, wherein the material inlet is connected to the clear liquid delivery pump BP103, the concentrated liquid is output from the bottom outlet of the tower and returned to the paint waste solvent storage tank, and the recovered solvent is output from the top of the tower as a product.

[0032] The processing steps are as follows:

[0033] The waste solvent of the paint is added into the reactor R101 as raw material, and then the aqueous solution such as flocculant is added into the reactor R101, and after being fully stirred, it is transported to the filter F101 through the suspension delivery pump AP101, and the filter F101 filters out the solid impurities in the suspension after flocculation, and the clear liquid enters the clear liquid tank AV101, and the clear liquid delivery pump AP102 transports the clear liquid in the clear liquid tank AV101 to the adsorption tower T101 for adsorption, decolorization and purification, and then enters the clear liquid tank BV102, and the clear liquid delivery pump BP103 transports the material in the clear liquid storage tank BV102 to the distillation device D101, and the recovered solvent treated by the distillation device D101 is extracted from the top of the tower as a product, and the concentrated liquid in the tower bottom enters the waste solvent tank of the paint for subsequent recycling treatment according to this process.

[0034] The flocculant is a mixture of one or more of anionic polyacrylamide, cationic polyacrylamide, sodium polyacrylate, polysilicic acid, polyferric silicate and polyaluminium chloride.

[0035] Wherein, the flocculant aqueous solution is an aqueous solution with a mass concentration of 0.1%-20.0%.

[0036] Wherein, the mass ratio of the flocculant aqueous solution to the paint waste solvent is 0.1-1.5:4.0.

[0037] Wherein, the adsorption tower T101 is filled with activated carbon or ion exchange resin.

[0038] Wherein, the distillation and purification device adopts a packed tower with an operating pressure of 5kPa-70kPa.

[0039] Processing Example 1

[0040] The waste solvent of the paint is added to the reactor R101 as the liquid to be treated, and then the flocculant aqueous solution is added to the reactor R101, wherein the flocculant aqueous solution is a mixed aqueous solution of polysilicic acid and polysilicate iron with a mass concentration of 12.0%, and the mass ratio of the flocculant aqueous solution to the waste solvent of the paint is 0.1:1.0. After sufficient stirring, it is transported to the filter F101 through the suspension delivery pump P101. The filter F101 filters out the solid impurities in the suspension after flocculation, and the clear liquid enters the clear liquid tank AV101. The clear liquid delivery pump AP102 delivers the clear liquid to the adsorption tower T101 filled with ion exchange resin, and then enters the clear liquid tank BV102. The clear liquid delivery pump BP103 delivers the material in the clear liquid tank BV102 to the distillation device D101. The distillation and purification device adopts a packed tower method with an operating pressure of 40kPa. The recovered solvent treated by the distillation device D101 is extracted from the top of the tower as a product, and the concentrated liquid in the bottom of the tower enters the paint waste solvent tank for subsequent recycling treatment according to this process.

[0041] Processing Example 2

[0042] The waste solvent of the paint is added to the reactor R101 as the liquid to be treated, and then the flocculant aqueous solution is added to the reactor R101, wherein the flocculant aqueous solution is a mixed aqueous solution of sodium polyacrylate and cationic polyacrylamide with a mass concentration of 0.2%, and the mass ratio of the flocculant aqueous solution to the waste solvent of the paint is 1.2:4.0. After sufficient stirring, it is transported to the filter F101 through the suspension delivery pump P101. The filter F101 filters out the solid impurities of the suspension after flocculation, and the clear liquid enters the clear liquid tank AV1 01. The clear liquid delivery pump AP102 delivers the clear liquid to the adsorption tower T101 filled with activated carbon, and then enters the clear liquid tank BV102. The clear liquid delivery pump BP103 delivers the material in the clear liquid tank BV102 to the distillation device D101. The distillation and purification device adopts a packed tower method with an operating pressure of 10kPa. The recovered solvent treated by the distillation device D101 is extracted from the top of the tower as a product, and the concentrated liquid in the bottom of the tower enters the paint waste solvent tank for subsequent recycling treatment according to this process.

[0043] Processing Example 3

[0044] The waste solvent of the paint is added to the reactor R101 as the liquid to be treated, and then the flocculant aqueous solution is added to the reactor R101, wherein the flocculant aqueous solution is a cationic polyacrylamide aqueous solution with a mass concentration of 0.1%, and the mass ratio of the flocculant to the waste solvent is 1.5:4.0. After sufficient stirring, it is transported to the filter F101 through the suspension delivery pump P101. The filter F101 filters out the solid impurities of the suspension after flocculation, and the clear liquid enters the clear liquid tank AV101. The clear liquid delivery pump AP 102 transports the clear liquid to the adsorption tower T101 filled with ion exchange resin of activated carbon, and then enters the clear liquid storage tank BV102. The clear liquid delivery pump BP103 transports the material in the clear liquid storage tank BV102 to the distillation device D101. The distillation and purification device adopts a packed tower method with an operating pressure of 70kPa. The recovered solvent treated by the distillation device D101 is extracted from the top of the tower as a product, and the concentrated liquid in the bottom of the tower enters the paint waste solvent tank for subsequent recycling treatment according to this process.

[0045] The utility model discloses a system for recycling and reusing waste solvents of water-based paints with low solid content and low boiling point, which replaces the existing membrane separation unit with a distillation unit. The system is more effective in recycling waste solvents of water-based paints with low solid content and low boiling point. Meanwhile, the flocculation-distillation system has a relatively simple structure and low maintenance cost.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A system for recycling and reusing waste solvents from low-solid-content and low-boiling-point water-based paint, comprising a flocculation unit, an adsorption unit, and a distillation unit; The flocculation unit comprises a reactor (R101) for stirring the added paint waste solvent and the flocculant aqueous solution, a filter (F101) for filtering the suspension formed by the reaction in the reactor (R101), and a clear liquid tank A (V101) for collecting the clear liquid after filtration; Features: The adsorption unit includes an adsorption tower (T101) for performing adsorption and decolorization treatment on the clear liquid in the clear liquid tank A (V101); The distillation unit includes a clear liquid tank B (V102) for receiving the clear liquid after treatment by the adsorption tower (T101). At the same time, the clear liquid material is taken as a raw material into the distillation device (D101) for separation and purification. The purified recovered solvent is extracted from the top of the tower as a product, and the concentrated liquid in the bottom of the tower continues to enter the paint waste solvent storage tank for subsequent recycling treatment.

2. The system for recycling and reusing waste solvents of low-solid-content and low-boiling-point water-based paint according to claim 1, characterized in that: The flocculation unit further comprises a suspension delivery pump (P101) for delivering the suspension in the reaction kettle (R101) to the filter (F101).

3. The system for recycling and reusing waste solvents of low-solid-content and low-boiling-point water-based paint according to claim 1, characterized in that: The adsorption unit further comprises a clear liquid delivery pump A (P102) for delivering the clear liquid in the clear liquid tank A (V101) to the adsorption tower (T101).

4. The system for recycling and reusing waste solvents of low-solid-content and low-boiling-point water-based paint according to claim 1, characterized in that: The distillation unit further comprises a clear liquid delivery pump B (P103) for delivering the clear liquid in the clear liquid tank B (V102) as a raw material to the distillation device (D101).

5. The system for recycling and reusing waste solvents of low-solid-content and low-boiling-point water-based paint according to claim 1, characterized in that: The adsorption tower (T101) is filled with activated carbon or ion exchange resin.

6. The system for recycling and reusing waste solvents of low-solid-content and low-boiling-point water-based paint according to claim 1, characterized in that: The distillation device (D101) adopts a packed tower method, and the operating pressure is 5kPa-70kPa.

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