A paint circulation filtration device for a painting line

Abstract

This utility model discloses a paint circulation and filtration device for a coating line, comprising: a receiving hopper; a filtration unit disposed directly below the receiving hopper, the filtration unit including a filter chamber and a filter assembly, the top of the filter chamber and the bottom of the receiving hopper being connected by a first connecting pipe, the filter assembly being used to filter the paint; and a circulation unit disposed directly below the filter chamber, the circulation unit including a collection box and a pump body, the top of the collection box and the bottom of the filter chamber being connected by a second connecting pipe, the pump body being installed on one side of the top of the collection box, the inlet end of the pump body being connected to an inlet pipe, the lower end of the inlet pipe extending to the bottom of the collection box, and the outlet end of the pump body being connected to an outlet pipe, the outlet pipe conveying the filtered paint to the paint supply system of the coating line to form a closed loop. This improves the recycling rate of previously wasted overflow paint, solves the resource waste problem caused by traditional direct discharge, reduces paint waste, and lowers production costs.

Description

Technical Field

[0001] This utility model relates to the technical field of coating lines, specifically to a paint circulation and filtration device for coating lines. Background Technology

[0002] A coating line is an automated production line used in industrial manufacturing for the protection and decoration of product surfaces. Its core processes include pretreatment, primer spraying, topcoat spraying, and curing and drying. The entire process is carried out in coordination through modules such as conveyor chains, robotic spraying equipment, and environmental control systems. It is widely used in the automotive, home appliance, aerospace, and 3C electronics industries to achieve efficient, uniform, and environmentally friendly surface coating processing.

[0003] During the painting process, some paint fails to adhere to the workpiece surface, resulting in "overflow". If the overflow is not recycled, it will lead to paint waste and increase production costs. The recycled paint needs to be filtered before it can be recycled. Otherwise, it will not be able to effectively remove particulate impurities (such as metal shavings and paint film clumps) from the paint, resulting in defects such as particles and pinholes on the workpiece surface after the recycled paint is sprayed.

[0004] Therefore, we need to propose a paint circulation and filtration device for coating lines. Utility Model Content

[0005] The purpose of this invention is to provide a paint recycling and filtration device for a coating line, which improves the recycling rate of previously wasted overflow material, solves the resource waste problem caused by traditional direct discharge, reduces paint waste, and lowers production costs, thereby addressing the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A paint circulation filtration device for a coating line includes:

[0008] The receiving hopper receives excess paint from the coating line.

[0009] A filtration unit is located directly below the receiving hopper. The filtration unit includes a filtration chamber and a filtration assembly. The top of the filtration chamber and the bottom of the receiving hopper are connected by a first connecting pipe. The filtration assembly is used to filter the coating.

[0010] The circulation unit is located directly below the filter chamber. The circulation unit includes a collection box and a pump body. The top of the collection box and the bottom of the filter chamber are connected by a second connecting pipe. The pump body is installed on the top side of the collection box. The inlet end of the pump body is connected to an inlet pipe. The lower end of the inlet pipe extends to the bottom of the collection box. The outlet end of the pump body is connected to an outlet pipe. The outlet pipe transports the filtered paint to the paint supply system of the coating line to form a closed loop.

[0011] Preferably, the filter unit includes three sets of covers, which are arranged longitudinally in sequence within the filter chamber. All three sets of covers are funnel-shaped with openings at the bottom.

[0012] Preferably, a first filter layer, a second filter layer, and a third filter layer are respectively installed in the bottom openings of the three sets of housings. The first filter layer, the second filter layer, and the third filter layer are arranged from top to bottom. The first filter layer is a perforated plate filter screen used to intercept large particulate impurities. The second filter layer is a pleated nylon filter screen. The edges of the filter screens of the first and second filter layers are connected to the housing with quick-release buckles. The third filter layer is a sintered metal filter element with a tubular filter element, which intercepts fine particles through micropores. The third filter layer is sealed to the housing with a sealing ring.

[0013] Preferably, one side of the filter chamber is equipped with an openable door for maintaining the filter assembly. The bottom of the filter chamber is funnel-shaped, and the funnel-shaped bottom and the funnel-shaped cover prevent paint from overflowing when the door is opened, facilitating maintenance.

[0014] Preferably, it also includes an anti-oxidation unit, which is set on the other side of the top of the collection box. The anti-oxidation unit includes a base and a nitrogen cylinder. The base is installed on the collection box, and the nitrogen cylinder is installed on the base. The gas inlet of the nitrogen cylinder is connected to a replacement pipe. The end of the replacement pipe extends into the inside of the collection box and is equipped with a microbubble aeration head to introduce nitrogen into the paint liquid below the surface of the collection box, thereby replacing the air in the tank and inhibiting solvent evaporation and paint oxidation.

[0015] Preferably, it also includes a heating unit disposed on the outer walls of both sides of the collection box. The heating unit includes a jacket and an electric heating wire. An insulating rod is installed inside the jacket, and the electric heating wire is wound around the insulating rod.

[0016] Compared with the prior art, the beneficial effects of this utility model are:

[0017] 1. The receiving hopper directly receives the overflow material from the coating line. After passing through the filtration unit and the circulation unit, a closed loop is formed, which improves the recycling rate of the originally wasted overflow material, solves the resource waste problem caused by traditional direct discharge, reduces paint waste, and lowers production costs.

[0018] 2. The overflow paint is directly received through the receiving hopper. Combined with the vertical three-stage filtration structure (perforated plate filter screen to intercept large particles, folded nylon filter screen to intercept medium particles, and sintered metal filter element to intercept micron-sized particles), it achieves gradient and efficient removal of impurities such as metal debris and paint film clumps in the paint, significantly reducing the defect rate of particles and pinholes on the workpiece surface after spraying with circulating paint, and improving the coating quality. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model;

[0020] Figure 2 This is a schematic diagram of the filter chamber of this utility model;

[0021] Figure 3 This is a schematic diagram of the structure of the collection box of this utility model;

[0022] Figure 4 This is a schematic diagram of the structure of the jacket of this utility model.

[0023] In the diagram: 1. Feeding hopper; 2. Filter chamber; 3. Collection box; 4. Pump body; 5. Cover; 6. First filter layer; 7. Nitrogen cylinder; 8. Replacement pipe; 9. Jacket; 10. Insulating rod; 11. Electric heating wire; 12. Second filter layer; 13. Third filter layer. Detailed Implementation

[0024] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0025] Please see Figure 1-3 This utility model provides a technical solution:

[0026] A paint circulation filtration device for a coating line includes:

[0027] The receiving hopper 1 receives the overflow paint from the coating line; the filter unit is located directly below the receiving hopper 1. The filter unit includes a filter chamber 2 and a filter assembly. The top of the filter chamber 2 and the bottom of the receiving hopper 1 are connected by a first connecting pipe. The filter assembly is used to filter the paint.

[0028] The circulation unit is located directly below the filter chamber 2. The circulation unit includes a collection box 3 and a pump body 4. The top of the collection box 3 and the bottom of the filter chamber 2 are connected by a second connecting pipe. The pump body 4 is installed on the top side of the collection box 3. The feed end of the pump body 4 is connected to a feed pipe, and the lower end of the feed pipe extends to the bottom of the collection box 3. The discharge end of the pump body 4 is connected to a discharge pipe, which transports the filtered paint to the paint supply system of the coating line to form a closed loop.

[0029] The receiving hopper 1 receives the overflow paint from the coating line and guides it into the filter chamber 2 directly below through the first connecting pipe. After the filter assembly filters the paint, the clean paint flows into the collection box 3 through the second connecting pipe. The pump 4 in the collection box 3 draws the bottom paint through the feed pipe and then sends it back to the paint supply system of the coating line through the discharge pipe, forming a closed loop of "recycling-filtration-reuse".

[0030] It achieves basic recycling and circulation of overflow material. The filtration unit initially removes impurities, and the circulation unit ensures a continuous supply of paint, solving the waste problem caused by the direct discharge of traditional overflow material.

[0031] Both the receiving hopper 1 and the filter chamber 2 can be supported and fixed by the collection box 3 via a bracket.

[0032] For a preferred embodiment, please refer to Figure 1-2 :

[0033] The filtration unit includes three sets of housings 5, which are arranged longitudinally within the filter chamber 2. All three sets of housings 5 ​​are funnel-shaped with openings at the bottom. A first filter layer 6, a second filter layer 12, and a third filter layer 13 are respectively installed within the bottom openings of the three sets of housings 5. These three filter layers are arranged from top to bottom. The first filter layer 6 is a perforated plate filter screen used to intercept large particles. The second filter layer 12 is a pleated nylon filter screen. The edges of the filter screens of the first filter layer 6 and the second filter layer 12 are connected to the housing 5 using quick-release clips. The third filter layer 13 is a tubular sintered metal filter element that intercepts fine particles through micropores. The third filter layer 13 is sealed to the housing using a sealing ring.

[0034] Three sets of funnel-shaped covers 5 are arranged longitudinally within the filter chamber 2, through which the paint flows sequentially to the first to third filter layers 13. The first filter layer 6 (perforated plate filter, pore size 1-2mm) intercepts impurities ≥1mm such as metal debris and large pieces of paint film; the second filter layer 12 (pleated nylon filter, 50μm precision) removes medium-sized particles by increasing the filtration area (the unfolded area is 3 times that of a traditional flat filter); the third filter layer 13 (tubular sintered metal filter element, 10μm precision) uses a microporous structure to intercept fine particles, and a sealing ring ensures that there is no bypass leakage of paint.

[0035] Gradient filtration (from coarse to fine) achieves graded removal of impurities, greatly improving overall filtration and preventing particles in the circulating paint from causing surface defects on the workpiece; quick-release clips shorten filter replacement time.

[0036] For a preferred embodiment, please refer to Figure 1-2 :

[0037] A closable door is installed on one side of the filter chamber 2 for maintenance of the filter assembly. The bottom of the filter chamber 2 is funnel-shaped. The funnel-shaped bottom of the filter chamber 2 and the funnel-shaped cover 5 prevent the paint from overflowing when the door is opened, which facilitates maintenance work.

[0038] The hinged door on one side of filter chamber 2 (connected by hinges and equipped with a sealing strip) can be opened for maintenance, facilitating the removal of the filter components. The funnel-shaped bottom and casing 5 design cause paint to collect at the bottom under gravity, preventing paint spillage when the door is opened. This provides convenient maintenance access, reducing operational obstacles during filter component replacement or cleaning; the spill-proof design reduces paint waste and workshop contamination, minimizing cleaning time per maintenance session.

[0039] For a preferred embodiment, please refer to Figure 1-3 :

[0040] It also includes an anti-oxidation unit, which is set on the other side of the top of the collection tank 3. The anti-oxidation unit includes a base and a nitrogen cylinder 7. The base is installed on the collection tank 3, and the nitrogen cylinder 7 is installed on the base. The gas inlet of the nitrogen cylinder 7 is connected to a replacement pipe 8. The end of the replacement pipe 8 extends into the inside of the collection tank 3 and is equipped with a microbubble aeration head to introduce nitrogen into the paint liquid below the surface of the collection tank 3 to replace the air in the tank and thus inhibit solvent evaporation and paint oxidation.

[0041] Nitrogen gas from the nitrogen cylinder 7 at the top of the collection tank 3 is introduced into the paint solution via a microbubble aerator (bubble diameter ≤1mm) through the replacement pipe 8. This gradually replaces the air in the collection tank 3 (reducing the oxygen content), thereby inhibiting paint oxidation and solvent evaporation. This extends the shelf life of the recycled paint, avoids abnormal viscosity or performance deterioration caused by oxidation, and reduces cost losses due to paint scrapping.

[0042] For a preferred embodiment, please refer to Figure 1-4 :

[0043] It also includes a heating unit, which is set on the outer walls of both sides of the collection box 3. The heating unit includes a jacket 9 and an electric heating wire 11. An insulating rod 10 is installed inside the jacket 9, and the electric heating wire 11 is wound around the insulating rod 10.

[0044] Inside the jackets 9 on both sides of the collection box 3, electric heating wires 11 (power 500-1000W) are wound around insulating rods 10. When energized, they generate heat and conduct it into the collection box 3. This, combined with the PLC controller on the control panel, maintains the paint temperature at 20-30℃±1℃, ensuring stable viscosity. This solves the problem of paint viscosity changes caused by ambient temperature fluctuations (such as increased viscosity at low temperatures clogging pipelines), ensures stable spraying pressure, and reduces the amount of diluent added for viscosity adjustments.

[0045] The collection box 3 is equipped with a control panel on its top. The control panel is controlled by a built-in PLC controller. The control circuit of the PLC controller can be easily programmed by those skilled in the art and is common knowledge in the field. Since this application is mainly used to protect mechanical devices, the control method and circuit connection will not be explained in detail here.

[0046] The collection box 3 has a built-in temperature sensor to monitor the temperature inside. The temperature sensor signal is connected to the control panel, and through a preset program, it controls the start and stop of the pump 4, the temperature adjustment of the heating unit, and the nitrogen supply to the anti-oxidation unit (e.g., automatically starting heating when the temperature is below 20℃), thus achieving automated operation of the device. This simplifies the operation process (eliminating the need for real-time manual monitoring), improves the stability and consistency of the device's operation, and reduces errors caused by human intervention.

[0047] The heating element 11 of the heating unit has a power (500-1000W) that can be adjusted in stages by the controller (e.g., full power at low temperatures, reduced to half power when approaching the target temperature) to achieve precise temperature control. At the same time, the temperature sensor continuously feeds back real-time data, forming a closed-loop control of "monitoring-judgment-execution-feedback" to ensure that the paint temperature remains stable within the set range.

[0048] The collection tank 3 is equipped with an oxygen content sensor (measurement range 0-21%, accuracy ±0.5%) to monitor the oxygen concentration in the air inside the tank in real time; it is also equipped with a liquid level sensor (to detect the paint liquid level) to ensure that the microbubble aerator head is always below the liquid surface (to prevent nitrogen from being directly discharged into the air). The sensors transmit the data in real time to the PLC controller on the control panel on top of the collection tank 3.

[0049] The PLC controller presets an oxygen concentration threshold (usually ≤5%). When the received oxygen content data is higher than the threshold, a start command is triggered; when the oxygen content drops below the threshold, a stop command is issued. Simultaneously, the controller, in conjunction with the liquid level sensor signal, will pause nitrogen supply and issue a low liquid level alarm if it detects that the liquid level is below the aeration head position.

[0050] The controller also works in conjunction with the heating unit. When the heating wire operates and causes the temperature inside the collection box 3 to rise, it automatically increases the nitrogen replacement frequency (e.g., replenishing nitrogen every 30 minutes) to maintain a stable oxygen content. In addition, the control panel can display the real-time oxygen content and nitrogen supply status, facilitating manual monitoring and parameter adjustment (e.g., modifying thresholds according to paint type).

[0051] Through the above-mentioned automated control, the anti-oxidation unit can continuously control the oxygen content in the collection box 3 within the set range without manual intervention, which not only ensures the anti-oxidation effect of the paint, but also avoids nitrogen waste.

[0052] A solenoid valve is installed between nitrogen cylinder 7 and replacement pipe 8. The PLC controller controls the opening and closing of the solenoid valve to automatically start and stop the nitrogen supply. When nitrogen filling is required, the solenoid valve opens, and nitrogen is introduced into the paint at a stable flow rate through the microbubble aerator head; after the set oxygen content is reached, the solenoid valve closes, and nitrogen filling stops.

[0053] The collection box is equipped with an exhaust port (10-15mm in diameter) with a one-way valve at the top. The one-way valve opening pressure is set to 0.01-0.02MPa. When nitrogen is introduced into the collection box through the microbubble aerator, the air pressure inside the box gradually increases with the injection of nitrogen. When the pressure exceeds the opening pressure of the one-way valve, the one-way valve opens automatically, and the air (containing a high concentration of oxygen) displaced by the nitrogen is discharged through the exhaust port. When the oxygen content inside the box drops to the set threshold (≤5%), the solenoid valve closes to stop nitrogen filling, the air pressure inside the box drops, and the one-way valve closes under the action of spring force to prevent external air backflow.

[0054] In addition, the exhaust port can be connected to an activated carbon filter to adsorb trace amounts of solvent vapor in the exhaust air, reducing pollution to the workshop environment. This structure requires no additional power and automatically completes exhaust through air pressure difference, forming a dynamic balance with the nitrogen supply to ensure that the oxygen content in the collection box is stably controlled within the set range.

[0055] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A paint line paint circulation filtering device, characterized by, include: The receiving hopper (1) receives the overflow paint from the coating line; A filter unit is located directly below the receiving hopper (1). The filter unit includes a filter chamber (2) and a filter assembly. The top of the filter chamber (2) and the bottom of the receiving hopper (1) are connected by a first connecting pipe. The filter assembly is used to filter the coating. The circulation unit is located directly below the filter chamber (2). The circulation unit includes a collection box (3) and a pump body (4). The top of the collection box (3) and the bottom of the filter chamber (2) are connected by a second connecting pipe. The pump body (4) is installed on the top side of the collection box (3). The feed end of the pump body (4) is connected to a feed pipe. The lower end of the feed pipe extends to the bottom of the collection box (3). The discharge end of the pump body (4) is connected to a discharge pipe. The discharge pipe transports the filtered paint to the paint supply system of the coating line to form a closed loop.

2. The paint circulation filtering device for a painting line according to claim 1, characterized by: The filter unit includes three sets of covers (5), which are arranged longitudinally in the filter chamber (2). All three sets of covers (5) are funnel-shaped with openings at the bottom.

3. A paint circulation filtering device for a painting line according to claim 2, characterized in that: The bottom openings of the three sets of housings (5) are respectively equipped with a first filter layer (6), a second filter layer (12) and a third filter layer (13). The first filter layer (6), the second filter layer (12) and the third filter layer (13) are arranged from top to bottom. The first filter layer (6) is a perforated plate filter screen used to intercept large particles of impurities. The second filter layer (12) is a folded nylon filter screen. The filter screen edges of the first filter layer (6) and the second filter layer (12) are connected to the housing (5) by quick-release buckles. The third filter layer (13) is a sintered metal filter element with a tubular filter element, which intercepts fine particles through micropores. The third filter layer (13) is sealed to the housing by a sealing ring.

4. The paint circulation filtering device for a painting line according to claim 2, characterized by: The filter chamber (2) is equipped with an openable door on one side for maintaining the filter assembly. The bottom of the filter chamber (2) is funnel-shaped. The funnel-shaped bottom of the filter chamber (2) and the funnel-shaped cover (5) prevent the paint from overflowing when the door is opened, which facilitates maintenance work.

5. The paint circulation filtering device for a painting line according to claim 1, characterized by: It also includes an anti-oxidation unit, which is set on the other side of the top of the collection box (3). The anti-oxidation unit includes a base and a nitrogen cylinder (7). The base is installed on the collection box (3), and the nitrogen cylinder (7) is installed on the base. The gas inlet of the nitrogen cylinder (7) is connected to a replacement pipe (8). The end of the replacement pipe (8) extends into the inside of the collection box (3) and is equipped with a microbubble aeration head. Nitrogen gas is introduced into the collection box (3) below the surface of the paint liquid to replace the air in the tank, thereby inhibiting solvent evaporation and paint oxidation.

6. The paint circulation filtration device for a coating line according to claim 1, characterized in that: It also includes a heating unit, which is set on the outer walls of both sides of the collection box (3). The heating unit includes a jacket (9) and an electric heating wire (11). An insulating rod (10) is installed inside the jacket (9), and the electric heating wire (11) is wound around the insulating rod (10).

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