Water-based waste solvent weight reduction treatment and cleaning fluid recovery system for coating workshop of automobile factory

Abstract

The utility model relates to the technical field of environmental protection, energy conservation and resource recycling, in particular to a water-based waste solvent weight reduction treatment and cleaning fluid recovery system for a coating workshop of an automobile factory. The system is composed of a water-based waste liquid tank, a pretreatment agent box A, a pretreatment agent box B, a stirring and mixing tank, a solid-liquid separation device, a transfer tank, a decompression fractionation device, a cooling device and a recovery tank which are connected through pipelines and control valves to form a complete treatment and recovery system. The utility model aims to solve the problems of high treatment cost, low recovery rate, serious environmental pollution and the like in the prior art, and provides a system capable of efficiently treating the water-based waste solvent in the coating workshop of the automobile factory and recovering the cleaning solution at low cost.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental protection, energy saving and resource recycling, and in particular to a system for weight reduction treatment of aqueous waste solvents and recycling of cleaning liquids in a paint shop of an automobile factory. Background Art

[0002] In the production and manufacturing of passenger car painting, paint filling tanks and rotary cups need to be cleaned when switching colors, which produces water-based waste solvents containing resins, color pastes, pigments, solvents, aluminum powder, glass beads, etc. Due to the differences in paint formulas for different brands, colors and performance requirements, the waste solvents produced after cleaning have very different components, making it difficult to handle them at a low cost, which has always been a difficulty that plagues the passenger car painting industry.

[0003] The methods for treating aqueous waste solvents in the prior art include: (1) directly entrusting the aqueous waste solvent to a professional manufacturer with hazardous waste treatment qualifications for disposal; (2) fully mixing the aqueous waste solvent and the flocculant to cause flocculation and coagulation of the macromolecular substances, filtering the mixed solution multiple times through a three-stage organic membrane system or an inorganic ceramic membrane system, and reusing the recovered liquid after filtration to achieve waste liquid recovery and weight reduction; (3) after pre-treating and classifying the aqueous waste solvent to remove foreign matter, adding relevant agents to demulsify the solution to form a mixture of paint residue and solution, and passing the mixed solution through a filtration system for solid-liquid separation to separate the solution from the paint residue, and enriching the solution with solvent to separate a small amount of water from a large amount of solvent. The separated wastewater is discharged in compliance with the standards after secondary treatment of the wastewater, and the solvent mixture is purified.

[0004] However, the above methods have the following defects: (1) The outsourcing disposal cost of Scheme 1 is high, and it is impossible to recover the effective cost of waste liquid. High-temperature incineration and other methods cause great pollution to the environment; (2) The core application of Scheme 2 is membrane separation, in which organic membranes are expensive, membrane groups are easy to clog, and are frequently replaced, which greatly increases operating costs. Inorganic membranes require a large one-time investment and a long recovery cycle. Regardless of whether it is an organic membrane or an inorganic module, although the amount of waste liquid is reduced, the replaced waste modules and backwashing generate new hazardous wastes, affecting the economic feasibility of the project; (3) Scheme 3 does not have thorough pre-treatment, and solid-liquid separation relies on filters. After solvent enrichment, most of the wastewater still needs to be discharged after secondary treatment to reduce COD. The weight reduction of waste is not obvious, and the recovery and reuse rate of cleaning solvents is low. The replacement of filters, ultrafiltration membranes, etc. leads to high operating costs and generates new solid hazardous wastes, resulting in poor project economics.

[0005] At the same time, in the production and manufacturing of passenger car painting, the composition of aqueous waste solvents of passenger cars is complex, among which resins, water, solvents, pigments, etc. are wrapped around each other, presenting a stable emulsion state, which is difficult to separate accurately; macromolecular materials such as resins, metal powders and other substances can easily clog the permeation holes of organic / inorganic membranes, reducing filtration efficiency and greatly increasing the frequency of module replacement; the COD value of aqueous waste solvents of passenger cars is extremely high, generally exceeding 300,000 mg / L, and generally cannot meet direct emission standards after treatment, and secondary water quality treatment is still required. Utility Model Content

[0006] The utility model aims to solve the problems of high processing cost, low recovery rate, serious environmental pollution and the like in the prior art, and provides a system capable of efficiently and low-costly processing aqueous waste solvents in a paint shop of an automobile factory and recovering cleaning liquid.

[0007] The technical solution adopted by the utility model is: a water-based waste solvent weight reduction treatment and cleaning liquid recovery system for a paint shop of an automobile factory, which is composed of a water-based waste liquid tank, a pretreatment agent box A, a pretreatment agent box B, a stirring and mixing tank, a solid-liquid separation device, a transfer tank, a vacuum fractionation device, a cooling device, and a recovery tank. The output end of the water-based waste liquid tank is connected to the input end of the stirring and mixing tank for supplying the water-based waste solvent into the stirring and mixing tank; the pretreatment agent box A and the pretreatment agent box B are both provided with a metering pump, and the pretreatment agent box The output end of the reagent box A and the output end of the pretreatment reagent box B are both connected to the input end of the stirring and mixing tank, and are used to transport the pretreatment reagent A and the pretreatment reagent B into the stirring and mixing tank; the stirring and mixing tank is provided with a stirring device, which is used to uniformly mix the aqueous waste solvent with the pretreatment reagent A and the pretreatment reagent B, and the output end of the stirring and mixing tank is connected to the input end of the solid-liquid separation device; the solid-liquid separation device is provided with a discharge port and a slag discharge port, and the discharge port of the solid-liquid separation device is connected to the input end of the transfer tank, and the solid-liquid separation The device adopts a small and simple sedimentation tank structure, separates the clear liquid and transports it to the transfer tank through the liquid discharge port, and discharges the sediment through the slag discharge port; the output end of the transfer tank is connected with the input end of the vacuum fractionation device, and a liquid level sensor and an automatic control system are arranged in the transfer tank, which are used to monitor the liquid level of the clear liquid, and automatically transport the clear liquid to the vacuum fractionation device when the preset liquid level is reached; the vacuum fractionation device is provided with a vacuum pump and a temperature control system, which are used to create and maintain the vacuum degree and control the fractionation temperature; the output end of the vacuum fractionation device is connected with the input end of the cooling device, which is used to transport the solvent effective components into the cooling device, and the discharge end of the vacuum fractionation device discharges the pretreatment agent A and the pretreatment agent B waste liquid; the cooling device adopts a normal temperature cooling method to liquefy the solvent active component vapor, and the output end of the cooling device is connected with the input end of the recovery tank, which is used to transport the liquefied solvent effective components into the recovery tank; the recovery tank is provided with a liquid level meter and an alarm system, which are used to monitor the liquid level of the liquid in the recovery tank and sound an alarm when the liquid level is too high.

[0008] As a further improvement of the utility model, the aqueous waste liquid tank is connected to the stirring and mixing tank through a pipeline 1 and a first control valve is provided on the pipeline 1.

[0009] As a further improvement of the utility model, the pretreatment agent box A is connected to the stirring and mixing tank through pipeline 2 and a second control valve is provided on pipeline 2, and the pretreatment agent box B is connected to the stirring and mixing tank through pipeline 3 and a third control valve is provided on pipeline 3.

[0010] As a further improvement of the utility model, the stirring mixing tank is connected to the solid-liquid separation device through a pipeline four and a fourth control valve is provided on the pipeline four.

[0011] As a further improvement of the utility model, the solid-liquid separation device is connected to the transfer tank through a pipeline five, and a fifth control valve and a filtering system are provided on the pipeline five.

[0012] As a further improvement of the present invention, the slag discharge port of the solid-liquid separation device is connected to a paint residue dryer for drying the sediment.

[0013] As a further improvement of the utility model, the discharge end of the vacuum fractionation equipment is connected to a concentrated waste liquid storage tank for storing the pre-treatment agent A and the pre-treatment agent B waste liquid.

[0014] As a further improvement of the utility model, the transfer tank is connected to the vacuum distillation device through pipeline six, the vacuum distillation device is connected to the cooling device through pipeline seven, and the cooling device is connected to the recovery tank through pipeline eight.

[0015] Beneficial effects of the utility model:

[0016] (1) The pretreatment agent A and the pretreatment agent B of the utility model are flocculants and demulsifiers, respectively, which can completely break the emulsified state of the aqueous waste solvent, perform thorough separation, completely separate the effective components and the ineffective components, and naturally settle the ineffective components, thereby achieving a high weight loss rate and a high recovery rate.

[0017] (2) The dripping property of the recovered liquid of the utility model is better than that of the original cleaning solvent, and its solubility is equivalent to that of the original cleaning solvent: the vacuum distillation technology is used to accurately control the distillation temperature, and only the effective components of the solvent are distilled out. In addition to the effective components coming from the original cleaning solvent, the solvent in the coating is also distilled simultaneously, which increases the purity of the solvent in the recovered liquid, and has a stronger component cleaning effect than the membrane group separation recovery method.

[0018] (3) The treatment process of the utility model does not need to filter and separate the solution through a membrane group, which greatly reduces the operating cost of waste solvent weight reduction, has excellent scalability, and can greatly reduce energy consumption, with a relatively small overall investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The utility model is an overall flow chart of a water-based waste solvent weight reduction treatment and cleaning liquid recovery system in a paint shop of an automobile factory.

[0020] As shown in the figure: 1. Aqueous waste liquid tank; 2. Pretreatment agent box A; 3. Pretreatment agent box B; 4. Stirring and mixing tank; 5. Solid-liquid separation device; 6. Transfer tank; 7. Vacuum distillation equipment; 8. Cooling equipment; 9. Recovery tank; 10. Paint residue dryer; 11. Concentrated waste liquid storage tank. DETAILED DESCRIPTION

[0021] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc. mentioned or may be mentioned in this specification are defined relative to their structure and are relative concepts. Therefore, they may change accordingly according to their different locations and different usage states; therefore, these or other directional terms should not be interpreted as restrictive terms.

[0022] The singular forms "a", "said" and "the" used in this specification are intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and implementation methods. It should be understood that the implementation methods described herein are only used to explain this application and are not used to limit this application.

[0024] The utility model provides the following Figure 1 The water-based waste solvent weight reduction treatment and cleaning liquid recovery system of the automobile factory paint shop shown in the figure is composed of a water-based waste liquid tank 1, a pretreatment agent tank A2, a pretreatment agent tank B3, a stirring and mixing tank 4, a solid-liquid separation device 5, a transfer tank 6, a vacuum fractionation device 7, a cooling device 8, and a recovery tank 9.

[0025] In the utility model, the aqueous waste liquid tank 1 is connected with the stirring and mixing tank 4 through a pipeline 1, and a first control valve is provided on the pipeline 1 for supplying the aqueous waste solvent into the stirring and mixing tank 4;

[0026] In the utility model, both the pre-treatment agent box A2 and the pre-treatment agent box B3 are provided with metering pumps, the pre-treatment agent box A2 is connected with the stirring and mixing tank 4 through the pipeline 2 and the pipeline 2 is provided with a second control valve, the pre-treatment agent box B3 is connected with the stirring and mixing tank 4 through the pipeline 3 and the pipeline 3 is provided with a third control valve, which is used to transport the pre-treatment agent A and the pre-treatment agent B into the stirring and mixing tank 4;

[0027] In the utility model, a stirring device is provided in the stirring and mixing tank 4, which is used to uniformly mix the aqueous waste solvent with the pretreatment agent A and the pretreatment agent B. The stirring and mixing tank 4 is connected to the solid-liquid separation device 5 through a pipeline 4, and a fourth control valve is provided on the pipeline 4;

[0028] The solid-liquid separation device 5 of the utility model is provided with a liquid discharge port and a slag discharge port. The solid-liquid separation device 5 is connected with the transfer tank 6 through a pipeline 5, and a fifth control valve and a filtering system are provided on the pipeline 5. The solid-liquid separation device 5 adopts a small and simple sedimentation tank structure, separates the clear liquid and transports it to the transfer tank 6 through the liquid discharge port, and discharges the sediment to the paint residue dryer 10 through the slag discharge port for drying the sediment;

[0029] In the utility model, the transfer tank 6 is connected with the vacuum fractionation device 7 through a pipeline 6. A liquid level sensor and an automatic control system are provided in the transfer tank 6 to monitor the liquid level of the clear liquid and automatically transport the clear liquid to the vacuum fractionation device 7 when the preset liquid level is reached;

[0030] In the utility model, a vacuum pump and a temperature control system are provided in the vacuum fractionation device 7, which are used to create and maintain the vacuum degree and control the fractionation temperature. The vacuum fractionation device 7 is connected with the cooling device 8 through a pipeline 7. The output end of the vacuum fractionation device is used to transport the solvent effective components into the cooling device 8. The discharge end of the vacuum fractionation device 7 discharges the waste liquid of the pre-treatment agent A and the pre-treatment agent B to the concentrated waste liquid storage tank 11, which is used to store the waste liquid of the pre-treatment agent A and the pre-treatment agent B.

[0031] The cooling device 8 in the utility model adopts a normal temperature cooling method to liquefy the solvent active ingredient vapor, and the cooling device 8 is connected to the recovery tank 9 through a pipeline 8 for conveying the liquefied solvent active ingredient into the recovery tank 9;

[0032] In the utility model, a liquid level meter and an alarm system are arranged in the recovery tank 9 to monitor the liquid level in the recovery tank 9 and to sound an alarm when the liquid level is too high.

[0033] Example:

[0034] In practical applications, the water-based waste solvent weight reduction treatment and cleaning liquid recovery system of the automobile factory paint shop of the utility model has shown significant advantages. The following is a specific embodiment for more detailed explanation of the operation process and effect of the utility model.

[0035] A certain automobile factory paint shop produces a large amount of aqueous waste solvents every day, which contain many valuable solvent components. In order to effectively recycle these solvents and reduce the discharge of waste solvents, the factory decided to introduce the aqueous waste solvent weight reduction treatment and cleaning liquid recovery system of the utility model.

[0036] First, the worker inputs the collected aqueous waste solvent into the stirring and mixing tank 4 through pipeline 1. Then, the flocculant in the pre-treatment agent tank A2 and the demulsifier in the pre-treatment agent tank B3 are respectively added into the stirring and mixing tank 4 through pipeline 2 and pipeline 3 through the metering pump. Under the action of the stirring device, the aqueous waste solvent is fully mixed with the pre-treatment agent A and the pre-treatment agent B, thereby breaking the emulsified state of the aqueous waste solvent and achieving a thorough separation of the effective components and the ineffective components.

[0037] Subsequently, the mixed liquid is transported to the solid-liquid separation device 5 through the pipeline 4. Under the action of the small simple sedimentation tank structure, the clear liquid is separated and transported to the transfer tank 6 through the liquid discharge port and the pipeline 5, while the sludge is transported to the paint residue dryer 10 through the slag discharge port for drying. The dried paint residue can be further processed or recycled as solid waste.

[0038] When the clear liquid in the transfer tank 6 reaches the preset liquid level, the liquid level sensor triggers the automatic control system to automatically transport the clear liquid to the vacuum fractionation device 7 through the pipeline 6. In the vacuum fractionation device 7, the effective components of the solvent are fractionated through the precise control of the vacuum pump and the temperature control system, and are transported to the cooling device 8 through the pipeline 7 for cooling and liquefaction. At the same time, the waste liquid of the pre-treatment agent A and the pre-treatment agent B is discharged to the concentrated waste liquid storage tank 11 for storage and treatment.

[0039] Finally, the solvent active ingredients after cooling and liquefaction are transported to the recovery tank 9 through the pipeline 8. In the recovery tank 9, through the monitoring of the liquid level meter and the alarm system, the workers can timely understand the liquid level of the liquid in the recovery tank 9 to ensure the smooth progress of the recovery process.

[0040] After a period of operation, the automobile factory found that after using the aqueous waste solvent weight reduction treatment and cleaning liquid recovery system of the utility model, the weight reduction rate of the waste solvent was significantly improved, and the quality of the recovered solvent was also effectively improved. At the same time, since the system does not need to filter and separate the solution through a membrane group, the operating cost of waste solvent weight reduction is greatly reduced, and energy consumption is reduced. The overall investment is relatively small, so the system has been widely used and promoted in the paint shop of automobile factories.

[0041] The above implementation modes are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned implementation modes, a person skilled in the art should understand that the technical solutions described in the aforementioned implementation modes can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the implementation modes of the present invention.

Claims

1. Automobile factory paint shop water-based waste solvent weight reduction treatment and cleaning liquid recovery system, characterized by: It is composed of an aqueous waste liquid tank (1), a pretreatment agent tank A (2), a pretreatment agent tank B (3), a stirring and mixing tank (4), a solid-liquid separation device (5), a transfer tank (6), a vacuum fractionation device (7), a cooling device (8), and a recovery tank (9). The output end of the aqueous waste liquid tank (1) is connected to the input end of the stirring and mixing tank (4) and is used to supply the aqueous waste solvent into the stirring and mixing tank (4); The pre-treatment agent box A (2) and the pre-treatment agent box B (3) are both provided with metering pumps, and the output ends of the pre-treatment agent box A (2) and the output ends of the pre-treatment agent box B (3) are both connected to the input end of the stirring and mixing tank (4), so as to transport the pre-treatment agent A and the pre-treatment agent B into the stirring and mixing tank (4); The stirring and mixing tank (4) is provided with a stirring device for uniformly mixing the aqueous waste solvent with the pretreatment agent A and the pretreatment agent B. The output end of the stirring and mixing tank (4) is connected to the input end of the solid-liquid separation device (5); The solid-liquid separation device (5) is provided with a liquid discharge port and a slag discharge port, and the liquid discharge port of the solid-liquid separation device (5) is connected to the input end of the transfer tank (6). The solid-liquid separation device (5) adopts a small and simple sedimentation tank structure, separates the clear liquid and transports it to the transfer tank (6) through the liquid discharge port, and discharges the sediment through the slag discharge port; The output end of the transfer tank (6) is connected to the input end of the vacuum fractionation device (7). The transfer tank (6) is provided with a liquid level sensor and an automatic control system for monitoring the liquid level of the clear liquid and automatically conveying the clear liquid to the vacuum fractionation device (7) when the preset liquid level is reached; The vacuum fractionation device (7) is provided with a vacuum pump and a temperature control system for producing and maintaining a vacuum degree and controlling a fractionation temperature. The output end of the vacuum fractionation device (7) is connected to the input end of the cooling device (8) for conveying effective components of the solvent into the cooling device (8). The discharge end of the vacuum fractionation device (7) discharges waste liquid of the pretreatment agent A and the pretreatment agent B. The cooling device (8) uses a normal temperature cooling method to liquefy the solvent active ingredient vapor, and the output end of the cooling device (8) is connected to the input end of the recovery tank (9) for conveying the liquefied solvent active ingredient into the recovery tank (9); The recovery tank (9) is provided with a liquid level meter and an alarm system for monitoring the liquid level in the recovery tank (9) and sounding an alarm when the liquid level is too high.

2. The system for reducing weight of aqueous waste solvent and recovering cleaning liquid in a paint shop of an automobile factory according to claim 1, characterized in that: The aqueous waste liquid tank (1) is connected to the stirring and mixing tank (4) via a pipeline 1, and a first control valve is provided on the pipeline 1.

3. The system for reducing weight of aqueous waste solvent and recovering cleaning liquid in a paint shop of an automobile factory according to claim 1, characterized in that: The pre-treatment reagent box A (2) is connected to the stirring and mixing tank (4) through pipeline two, and a second control valve is provided on pipeline two. The pre-treatment reagent box B (3) is connected to the stirring and mixing tank (4) through pipeline three, and a third control valve is provided on pipeline three.

4. The system for reducing weight of aqueous waste solvent and recovering cleaning liquid in a paint shop of an automobile factory according to claim 1, characterized in that: The stirring and mixing tank (4) is connected to the solid-liquid separation device (5) via a pipeline four, and a fourth control valve is provided on the pipeline four.

5. The system for reducing weight of aqueous waste solvent and recovering cleaning liquid in a paint shop of an automobile factory according to claim 1, characterized in that: The solid-liquid separation device (5) is connected to the transfer tank (6) via a pipeline five, and a fifth control valve and a filtering system are provided on the pipeline five.

6. The system for reducing weight of aqueous waste solvent and recovering cleaning liquid in a paint shop of an automobile factory according to claim 1, characterized in that: The slag discharge port of the solid-liquid separation device (5) is connected to a paint residue dryer (10) for drying the sludge.

7. The system for reducing weight of aqueous waste solvent and recovering cleaning liquid in a paint shop of an automobile factory according to claim 1, characterized in that: The discharge end of the vacuum fractionation device (7) is connected to a concentrated waste liquid storage tank (11) for storing the pre-treatment agent A and pre-treatment agent B waste liquid.

8. The system for reducing weight of aqueous waste solvent and recovering cleaning liquid in a paint shop of an automobile factory according to claim 1, characterized in that: The transfer tank (6) is connected to the vacuum fractionation device (7) via a pipeline six, the vacuum fractionation device (7) is connected to the cooling device (8) via a pipeline seven, and the cooling device (8) is connected to the recovery tank (9) via a pipeline eight.

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