Automobile coating waste solvent recovery device

Abstract

The utility model discloses an automobile coating waste solvent recovery device, which comprises a coarse filter, a bag filter and a fine filter, a horizontally arranged filter screen is arranged in the coarse filter, a liquid outlet is arranged above the filter screen in the coarse filter, and a feed inlet is arranged below the filter screen in the coarse filter; the bag type filter comprises a vertically arranged filter cartridge and a filter bag fixed in the filter cartridge, a liquid inlet communicated with the interior of the filter bag is formed in the top of the filter cartridge, a liquid outlet is formed in the side face of the filter cartridge and located on the periphery of the filter bag, and an emptying opening is formed in the bottom of the filter cartridge and located on the periphery of the filter bag; the fine filter comprises a shell and a filter element installed in the shell, the filter element is of a vertically-arranged rod-shaped structure, a liquid inlet cavity is formed in the top of the shell, a liquid outlet is formed in the side face of the shell, and an emptying opening is formed in the bottom of the shell. A liquid outlet of the coarse filter is communicated with a liquid inlet of the bag type filter, and a liquid outlet of the bag type filter is communicated with a liquid inlet cavity of the fine filter. According to the utility model, not only can the solvent be recycled, but also the hazardous waste treatment capacity can be reduced.

Description

Technical Field

[0001] This utility model relates to a waste solvent recovery device for automotive painting, belonging to the field of organic solvent recovery technology. Background Technology

[0002] Automotive painting waste solvents are mainly composed of a mixture of trimethylbenzene, tetramethylbenzene, ethylene glycol, and butyl ether, with small amounts of other hazardous substances such as butyl acetate. Currently, automotive painting waste solvents are not recycled and are instead treated as hazardous waste by qualified environmental protection companies.

[0003] Within the industry, the production volume of waste solvents from automotive painting is relatively small, making recycling difficult. A typical company generates 1000-6000 kg of waste solvents daily, but a company may have multiple branches, resulting in even smaller amounts generated by each branch. Therefore, companies usually entrust hazardous waste to environmental protection companies for recycling. Qualified environmental protection companies incinerate the waste solvents in incinerators, which produces large amounts of harmful gases. Although a series of measures are taken to ensure that the flue gas meets emission standards, harmful substances still remain in the flue gas. Utility Model Content

[0004] The purpose of this invention is to provide a waste solvent recovery device for automotive painting, which solves the technical problem that waste solvents in automotive painting cannot be recycled and reused in the prior art.

[0005] This utility model adopts the following technical solution: a waste solvent recovery device for automotive painting, comprising a coarse filter, a bag filter, and a fine filter arranged in sequence. The coarse filter has a horizontally arranged filter screen, an outlet above the filter screen, and an inlet below the filter screen. The bag filter includes a vertically arranged filter cylinder and a filter bag fixed inside the filter cylinder. The top of the filter cylinder has an inlet communicating with the inside of the filter bag, the side of the filter cylinder has a drain port around the filter bag, and the bottom of the filter cylinder has a vent port around the filter bag. The drain port on the filter cylinder is higher than the vent port. The fine filter includes a shell and a filter element installed inside the shell. The filter element adopts a vertically arranged rod-shaped structure. The top of the shell has an inlet chamber, the side of the shell has a drain port, and the bottom of the shell has a vent port. The outlet of the coarse filter is connected to the inlet of the bag filter, and the outlet of the bag filter is connected to the inlet chamber of the fine filter.

[0006] The fine filter has two or more stages, with the drain port of the previous fine filter connected to the inlet port of the next fine filter.

[0007] The fine filter includes a primary fine filter, a secondary fine filter, and a tertiary fine filter arranged in sequence. The filter element in the primary fine filter has a filtration accuracy of 0.1 μm, the filter element in the secondary fine filter has a filtration accuracy of 0.04 μm, and the filter element in the tertiary fine filter has a filtration accuracy of 0.01 μm.

[0008] The filter elements in the primary, secondary, and tertiary fine filters are all composed of two or more cylindrical structures; each filter element is arranged in parallel at intervals.

[0009] The filter elements in the primary and secondary fine filters are sintered filter elements, while the filter element in the tertiary fine filter is a membrane filter element.

[0010] The filter bag is made of PTFE.

[0011] The filter bag has a filtration accuracy of 1 μm.

[0012] The upper part of the coarse filter is a square structure, and the lower part is a tapered structure that gradually tapers downwards. The filter screen is installed at the junction of the square structure and the tapered structure. The feed inlet of the coarse filter is located at the bottom of the tapered structure, and the liquid outlet of the coarse filter is located on the side wall of the square structure.

[0013] The pore size of the coarse filter screen is less than 10 μm.

[0014] The coarse filter uses a PTFE filter.

[0015] The beneficial effects of this invention are as follows: This invention uses a coarse filter, a bag filter, and a fine filter to sequentially filter automotive painting waste solvents. The coarse filter not only filters but also settles, removing most of the large-particle suspended solids in the waste solution. The precision of the coarse filter, bag filter, and fine filter progresses from coarse to fine, and through multiple filtrations, suspended solids in the waste solvent are removed. The liquid discharged from the final outlet can be recycled as solvent. Impurities filtered out by the coarse filter are discharged through the inlet and treated as hazardous waste, significantly reducing the amount of hazardous waste to be treated and achieving energy conservation and emission reduction. In summary, this invention not only enables solvent recycling but also reduces the amount of hazardous waste to be treated, realizing the resource utilization of waste solvents.

[0016] Preferably, this invention employs a multi-stage fine filter to remove suspended solids from the waste solvent as much as possible, thereby significantly reducing impurities in the solvent and facilitating subsequent recycling.

[0017] Preferably, the filter bags and filter screens are made of PTFE material, which can be reused 2-5 times, thus promoting energy conservation and environmental protection.

[0018] Preferably, the sintered filter element can be reused multiple times after cleaning, further contributing to energy conservation and environmental protection. Attached Figure Description

[0019] Figure 1 This is an overall schematic diagram of a waste solvent recovery device for automotive painting according to this utility model;

[0020] Figure 2 yes Figure 1 Schematic diagram of a coarse-medium filter;

[0021] Figure 3 yes Figure 1 A schematic diagram of a medium-sized bag filter;

[0022] Figure 4 yes Figure 1 A schematic diagram of a medium-fine filter.

[0023] In the diagram: 1-coarse filter, 1.1-filter screen, 1.2-feed inlet, 1.3-liquid outlet, 2-bag filter, 2.1-filter cartridge, 2.2-filter bag, 2.3-liquid inlet, 3-fine filter, 3.1-outer shell, 3.2-filter element, 3.3-liquid inlet chamber, 3a-first-stage fine filter, 3b-second-stage fine filter, 3c-third-stage fine filter. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0025] like Figures 1 to 4 As shown, an embodiment of the automotive painting waste solvent recovery device of this utility model includes a coarse filter 1, a bag filter 2, and a fine filter 3 arranged sequentially. The coarse filter 1 contains a horizontally arranged filter screen 1.1. An outlet 1.3 is located above the filter screen 1.1, and a feed inlet 1.2 is located below the filter screen 1.1. The upper part of the coarse filter 1 has a square structure, and the lower part has a tapered structure that gradually tapers downwards. The filter screen 1.1 is installed at the junction of the square and tapered structures. The feed inlet 1.2 of the coarse filter 1 is located at the bottom of the tapered structure, and the outlet 1.3 of the coarse filter 1 is located on the side wall of the square structure. The pore size of the filter screen 1.1 of the coarse filter 1 is less than 10 μm, and the filter screen 1.1 is a PTFE filter screen.

[0026] The bag filter 2 includes a vertically arranged filter cylinder 2.1 and a filter bag 2.2 fixed inside the filter cylinder 2.1. The top of the filter cylinder 2.1 has an inlet 2.3 communicating with the interior of the filter bag 2.2. A drain port is located on the side of the filter cylinder 2.1 around the outer periphery of the filter bag 2.2, and a vent is located at the bottom of the filter cylinder 2.1 around the outer periphery of the filter bag. The drain port on the filter cylinder 2.1 is positioned higher than the vent. The filtration accuracy of the filter bag 2.2 is 1 μm. The filter bag 2.2 is made of PTFE (polytetrafluoroethylene).

[0027] The fine filter 3 includes a housing 3.1 and a filter element 3.2 installed inside the housing 3.1. The filter element 3.2 adopts a vertically arranged rod-shaped structure. The top of the housing 3.1 is provided with a liquid inlet chamber 3.3, the side of the housing 3.1 is provided with a liquid outlet, and the bottom of the housing 3.1 is provided with a vent. The liquid outlet of the coarse filter 1 is connected to the liquid inlet of the bag filter 2, and the liquid outlet of the bag filter 2 is connected to the liquid inlet chamber of the fine filter 3.

[0028] The fine filter 3 has two or more stages, with the drain port of the previous fine filter connected to the inlet port of the next fine filter. In this embodiment, the fine filter 3 includes a first-stage fine filter 3a, a second-stage fine filter 3b, and a third-stage fine filter 3c arranged sequentially. The filtration accuracy of the filter element in the first-stage fine filter 3a is 0.1 μm, the filtration accuracy of the filter element in the second-stage fine filter 3b is 0.04 μm, and the filtration accuracy of the filter element 3.2 in the third-stage fine filter 3c is 0.01 μm. The filter elements in the first-stage fine filter 3a, the second-stage fine filter 3b, and the third-stage fine filter 3c are all filter elements with two or more cylindrical structures; the filter elements are arranged in parallel and spaced apart. The filter elements in the first-stage fine filter 3a and the second-stage fine filter 3b are sintered filter elements, and the filter element in the third-stage fine filter 3c is a membrane filter element.

[0029] During manufacturing, the coarse filter, bag filter, and various fine filters can be assembled into a single, movable unit. During operation, the waste solution is fed into the coarse filter through the bottom inlet. After passing through the filter screen, particles larger than 10μm are trapped below the screen. The filtered upper clear liquid exits through the outlet and enters the inlet of the bag filter, where particles larger than 1μm are trapped inside the filter bag. The filtered clear liquid then enters the fine filters for further filtration. The first, second, and third fine filters sequentially remove particles of 0.1μm, 0.04μm, and 0.01μm, respectively. The final filtered solution is discharged from the outlet of the third fine filter. The filtered solution contains very few impurities and has significantly reduced turbidity, reaching a set value (usually below 50 degrees Celsius), after which it can be recycled as a solvent. Finally, the impurities below the filter screen in the coarse filter are periodically discharged through the feed inlet and can be treated as hazardous waste. After the waste solvent is recycled and treated by this utility model, the amount of hazardous waste to be treated is greatly reduced.

[0030] During the trial operation of the equipment, the total TDS of the waste solvent before treatment was approximately 10,000-30,000 mg / L, and the total TDS after treatment was below 2 mg / L. It can recover approximately 1000 kg of waste solvent per day, achieving resource utilization without environmental pollution. Furthermore, based on current solvent market prices, the recovery value is 6000-9600 RMB per ton.

[0031] After the device has been running for a period of time, or after a certain amount of recovery has been achieved, another set of devices is switched to operate. The device that has reached the recovery target is cleaned. The residual liquid in the bag filter and fine filter is discharged from the bottom vent. Then the coarse filter, bag filter and fine filter are cleaned. The filter screen, filter bag and filter element can be reused after cleaning, thus realizing the recycling of the equipment.

[0032] The embodiments and descriptions above are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A device for recovering waste solvents from automotive painting, characterized in that: It includes a coarse filter, a bag filter, and a fine filter arranged in sequence. The coarse filter has a horizontally arranged filter screen, an outlet above the filter screen, and an inlet below the filter screen. The bag filter includes a vertically arranged filter cylinder and a filter bag fixed inside the filter cylinder. The top of the filter cylinder has an inlet communicating with the inside of the filter bag, the side of the filter cylinder has a drain outlet around the filter bag, and the bottom of the filter cylinder has a vent around the filter bag. The drain outlet on the filter cylinder is higher than the vent outlet. The fine filter includes a shell and a filter element installed inside the shell. The filter element has a vertically arranged rod-shaped structure. The top of the shell has an inlet chamber, the side of the shell has a drain outlet, and the bottom of the shell has a vent outlet. The outlet of the coarse filter is connected to the inlet of the bag filter, and the outlet of the bag filter is connected to the inlet chamber of the fine filter.

2. The automotive painting waste solvent recovery device according to claim 1, characterized in that: The fine filter has two or more stages, with the drain port of the previous fine filter connected to the inlet port of the next fine filter.

3. The automotive painting waste solvent recovery device according to claim 2, characterized in that: The fine filter includes a primary fine filter, a secondary fine filter, and a tertiary fine filter arranged in sequence. The filter element in the primary fine filter has a filtration accuracy of 0.1 μm, the filter element in the secondary fine filter has a filtration accuracy of 0.04 μm, and the filter element in the tertiary fine filter has a filtration accuracy of 0.01 μm.

4. The automotive painting waste solvent recovery device according to claim 3, characterized in that: The filter elements in the primary, secondary, and tertiary fine filters are all composed of two or more cylindrical structures; each filter element is arranged in parallel at intervals.

5. The automotive painting waste solvent recovery device according to claim 3 or 4, characterized in that: The filter elements in the primary and secondary fine filters are sintered filter elements, while the filter element in the tertiary fine filter is a membrane filter element.

6. The automotive painting waste solvent recovery device according to any one of claims 1 to 4, characterized in that: The filter bag is made of PTFE.

7. The automotive painting waste solvent recovery device according to any one of claims 1 to 4, characterized in that: The filter bag has a filtration accuracy of 1 μm or higher.

8. The automotive painting waste solvent recovery device according to any one of claims 1 to 4, characterized in that: The upper part of the coarse filter is a square structure, and the lower part is a tapered structure that gradually tapers downwards. The filter screen is installed at the junction of the square structure and the tapered structure. The feed inlet of the coarse filter is located at the bottom of the tapered structure, and the liquid outlet of the coarse filter is located on the side wall of the square structure.

9. The automotive painting waste solvent recovery device according to claim 8, characterized in that: The pore size of the coarse filter screen is less than 10 μm.

10. The automotive painting waste solvent recovery device according to claim 8, characterized in that: The coarse filter uses a PTFE filter.

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