Circulating filtration equipment for PCB (printed circuit board) manufacturing waste liquid

Abstract

The utility model discloses circulating filtering equipment for PCB (printed circuit board) manufacturing waste liquid. The circulating filtering equipment comprises a filtering cavity, a rotating mechanism, a rotary drum, a scraper and a liquid inlet, a liquid outlet and a slag outlet are formed in the filtering cavity. And the rotary drum is positioned in the filtering cavity and is in transmission connection with the rotating mechanism. The rotary drum is of a hollow structure, the liquid inlet is communicated with the interior of the rotary drum, and the scraper extends into the rotary drum and abuts against the inner wall of the rotary drum so as to be used for scraping filter residues adsorbed on the inner wall of the rotary drum. The rotating mechanism can drive the rotary drum to rotate, centrifugal force is generated when the rotary drum rotates, due to the fact that solid and liquid in the waste liquid are different in specific gravity and different in centrifugal force, impurities such as printing ink, dry film residues and jelly in the waste liquid can be thrown onto the inner wall of the rotary drum, and after filter residues are accumulated to a certain thickness, the scraper cleaning function is started, the filter residues can be scraped off, and the waste liquid can be recycled. The slag is discharged outwards through the slag discharging opening; and the clean liquid can flow back to the transfer tank or the medicine tank through the liquid outlet for recycling.

Description

Technical Field

[0001] The utility model belongs to the field of industrial wastewater purification equipment, and particularly relates to a circulating filtration device for waste liquid in PCB manufacturing. Background Art

[0002] In the manufacturing process of PCB (printed circuit board), the developer and the stripping solution are key process fluids used to remove impurities and form the required circuit patterns during the manufacturing process. Currently, there are mainly two types of developers: sodium carbonate and potassium carbonate. Among them, the sodium carbonate developer must be replaced every 12 hours, while the potassium carbonate developer is replaced every 3 - 5 days. Such frequent replacement will result in the generation of waste liquid and requires time for production suspension for the replacement operation.

[0003] These waste liquids generated in PCB manufacturing contain polymers, organic amines, alkalis, high - concentration organic wastewater (the wastewater is blue or dark green), with a chemical oxygen demand value usually of 10000 mg / L, and some as high as 20000 mg / L, and the suspended solids are about 800 - 1200 mg / L, usually showing strong alkalinity. If directly discharged, it will cause environmental pollution. In order to reduce the discharge of waste liquid and waste residue, improve the resource utilization efficiency, and reduce the production cost, PCB production enterprises need to use filtration equipment to treat these waste liquids.

[0004] However, the cotton core filtration method of existing filtration equipment has obvious deficiencies in treating these waste liquids. When there is too much ink residue, the cotton core cannot filter it completely, often resulting in the situation that the ink residue clogs the nozzle and the problem that the ink residue adheres back to the production board surface, which has a serious impact on the production quality. At the same time, the service life of the filter cotton core is relatively short and generally needs to be replaced every 1 - 2 days, which is not only time - consuming and labor - intensive, but also the replaced waste cotton core belongs to hazardous waste solids, and its treatment cost is also getting higher and higher. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a circulating filtration device for waste liquid in PCB manufacturing, which can circulate and filter the waste liquid in the PCB manufacturing process so that the waste liquid can be changed back to clean liquid for recycling.

[0006] The utility model is realized as follows: A circulating filtration device for waste liquid in PCB manufacturing includes a filtration cavity, a rotating mechanism, a rotating drum, a scraper, and a liquid inlet for inputting waste liquid; the rotating drum is located inside the filtration cavity, the rotating drum is in transmission connection with the rotating mechanism, and the rotating mechanism can drive the rotating drum to rotate;

[0007] The rotating drum is of a hollow structure, the liquid inlet is communicated with the inside of the rotating drum, the scraper extends into the inside of the rotating drum and abuts against the inner wall of the rotating drum to scrape off the filter residue adsorbed on the inner wall of the rotating drum;

[0008] The filtering cavity is provided with a liquid discharge port for discharging clean liquid and a slag discharge port for discharging filter residues.

[0009] Furthermore, there is a first gap between the outer side surface of the rotating drum and the inner wall of the filtering cavity, and a second gap between the bottom wall of the rotating drum and the bottom wall of the filtering cavity. The first gap and the second gap together serve as the outflow channel for clean liquid; the outflow channel is communicated with the liquid discharge port.

[0010] Furthermore, the liquid discharge port is located at the top position of the filtering cavity; the slag discharge port is located at the bottom position of the filtering cavity.

[0011] Furthermore, the rotating drum is a hollow cylindrical structure.

[0012] Furthermore, the circulating filtration device further includes a top cover. The top of the filtering cavity is an open end, and the top cover covers the opening at the top of the filtering cavity. The liquid inlet is arranged on the top cover.

[0013] Furthermore, the circulating filtration device further includes a scraper mounting rod. The top end of the scraper mounting rod is fixedly connected to the top cover, and its bottom end is fixedly connected to the scraper.

[0014] Furthermore, the rotating mechanism includes a motor, a belt pulley transmission assembly, and a rotating shaft. The motor is drivingly connected to the bottom end of the rotating shaft through the belt pulley transmission assembly. The top end of the rotating shaft is fixedly connected to the rotating drum, and the motor can drive the rotating drum to rotate at a set speed.

[0015] Furthermore, the peripheral edge of the top end of the rotating shaft is fixedly connected to the inner wall of the rotating drum through spokes.

[0016] Furthermore, the top of the rotating shaft is provided with a spoke mounting portion. The diameter of the spoke mounting portion is larger than the diameter of the rotating shaft. A plurality of the spokes are fixed on the outer peripheral edge of the spoke mounting portion and are circumferentially and separately distributed along the spoke mounting portion.

[0017] Furthermore, the circulating filtration device further includes a bottom box. The filtering cavity is fixed on the bottom box, and the rotating mechanism is installed inside the bottom box.

[0018] The circulating filtration equipment for PCB manufacturing waste liquid provided by the present utility model includes a filtration cavity, a rotating mechanism, a rotating drum and a scraper. The rotating drum is located inside the filtration cavity, and the rotating mechanism can drive the rotating drum to rotate. When the rotating drum rotates, centrifugal force is generated. Due to the different specific gravities of the solids and liquids in the waste liquid, the centrifugal forces they receive are different. Therefore, impurities such as ink, dry film residues, and colloids in the waste liquid will be thrown onto the inner wall of the rotating drum. After the filter residue accumulates to a certain thickness, the scraper cleaning function is started, and the filter residue can be scraped off and discharged out through the slag discharge port; while the clean liquid can flow back to the transfer tank or chemical tank through the liquid outlet for recycling.

[0019] Compared with the prior art, the present utility model has the following beneficial effects:

[0020] Realize solid-liquid separation: This circulating filtration equipment adopts the centrifugal cross-flow separation treatment technology, and realizes pure physical non-sticky plug solid-liquid separation through centrifugation, thoroughly filters fine ink residues and dry film residues, and then outputs the filter residue and clean liquid separately.

[0021] Prolong the service life of the chemical solution: 100% developer can be recycled. The service life of the developer sodium carbonate system can be extended to 7-10 days for discharge, and the potassium carbonate system can be extended to 10-15 days for discharge, reducing downtime, maintenance labor and chemical solution consumption, and easily solving the environmental protection discharge problem.

[0022] Reduce the amount and cost of sewage treatment: Adopting the centrifugal cross-flow separation treatment technology, compared with the cotton core filtration method, it can effectively reduce the amount of waste liquid treatment and the cost of waste liquid treatment, reduce the COD (chemical oxygen demand) value in the discharged sewage, meet the national discharge standards, and greatly reduce the pressure on the sewage treatment station to treat organic wastewater.

[0023] Reduce the tank changing time and maintenance cycle: By setting a reasonable rotation speed, the rotating drum can generate a strong centrifugal force (which can reach 1700 times the gravity of the impurities' own weight), improve the filtration accuracy, solve the problems of poor filtration effect with the traditional cotton core filtration, and quality problems such as nozzle blockage, incomplete development, and residue re-adhesion to the board surface when the filtered clean liquid is recycled. The present utility model can reduce the tank changing time of the developing tank and stripping tank; at the same time, the equipment adopts pure physical separation, without any foreign substances intervening, improving the cleanliness of the recycled liquid, making the components in contact with the recycled liquid such as the tank body and rollers not easily contaminated, and the nozzle not easily blocked, which can extend the maintenance time and reduce the maintenance frequency.

[0024] Increase the equipment utilization rate and production capacity: Reduce the maintenance labor, increase the equipment utilization rate, and thus increase the production capacity. Description of the Drawings

[0025] Figure 1 It is a structural schematic diagram of a circulating filtration equipment for PCB manufacturing waste liquid provided by an embodiment of the present utility model;

[0026] Figure 2 It is a flowchart of waste liquid treatment using the circulating filtration device of this embodiment.

[0027] Markings in the figure:

[0028] 1. Filtration cavity; 11. Liquid discharge port; 12. Slag discharge port; 2. Rotary drum; 3. Scraper; 4. Scraper mounting rod; 5. Top cover; 6. Bottom box; 7. Liquid inlet; 81. Motor; 82. Pulley drive assembly; 83. Rotating shaft; 84. Spoke mounting part; 9. Spoke. Specific embodiments

[0029] In order to make the objectives, technical solutions and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0030] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present utility model; the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance; in addition, unless otherwise clearly defined and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0031] Referring to Figure 1 , this embodiment provides a circulating filtration device for PCB manufacturing waste liquid, including a filtration cavity 1, a rotating mechanism, a rotary drum 2, a scraper 3, a scraper mounting rod 4, a top cover 5 and a bottom box 6.

[0032] The top end of the filtration cavity 1 is an open end, the top cover 5 covers the opening at the top end of the filtration cavity 1, a liquid inlet 7 for inputting waste liquid is provided on the top cover 5, the rotary drum 2 is located inside the filtration cavity 1, and the liquid inlet 7 is communicated with the inside of the rotary drum 2.

[0033] The filtering cavity 1 is provided with a liquid discharge port 11 for discharging clean liquid and a slag discharge port 12 for discharging filter residues. Preferably, the liquid discharge port 11 is located at the top of the filtering cavity 1, and the slag discharge port 12 is located at the bottom of the filtering cavity 1.

[0034] The rotating mechanism includes a motor 81, a pulley drive assembly 82, and a rotating shaft 83. The motor 81 is drivingly connected to the bottom end of the rotating shaft 83 through the pulley drive assembly 82, and the top end of the rotating shaft 83 is fixedly connected to the drum 2. The motor 81 can drive the drum 2 to rotate at a set speed.

[0035] The filtering cavity 1 is fixedly installed on the bottom box 6, and the rotating mechanism is fixedly installed inside the bottom box 6.

[0036] In this embodiment, the drum 2 is a hollow cylindrical structure. The drum 2 is equivalent to a rotor and can rotate at a high speed relative to the filtering cavity 1 under the drive of the motor 81. To ensure that the center line of the drum 2 coincides with the center line of the filtering cavity 1, the installation position of the rotating shaft 83 is aligned with the center position of the drum 2. The top of the rotating shaft 83 is provided with a spoke mounting portion 84, and a plurality of spokes 9 are fixed on the outer peripheral edge of the spoke mounting portion 84 and are circumferentially and separably distributed along the spoke mounting portion 84. Preferably, the diameter of the spoke mounting portion 84 is larger than the diameter of the rotating shaft 83 to ensure the connection area and connection strength between the spokes 9 and the spoke mounting portion 84.

[0037] The top end of the scraper mounting rod 4 is fixedly connected to the top cover 5, and the bottom end thereof is fixedly connected to the scraper 3. The scraper 3 extends into the drum 2 and abuts against the inner wall of the drum 2. When the drum 2 rotates, the scraper 3 can scrape off the filter residues adsorbed on the inner wall of the drum 2. After the filter residues fall off, they fall onto the slag discharge port 12 below and are discharged outwards. It is easy to understand that the scraper 3 can be used when needed (after the filter residues accumulate to a certain thickness), and when not in use, the scraper 3 can be withdrawn or moved to a position separated from the inner wall of the drum 2; the slag discharge port 12 is in a closed state usually and is opened only when filter residues need to be discharged.

[0038] To better ensure the cleanliness of the filtered liquid, there is a first gap between the outer side surface of the drum 2 and the inner wall of the filtering cavity 1, and a second gap between the bottom wall of the drum 2 and the bottom wall of the filtering cavity 1. The first gap and the second gap together serve as the outflow channel for the clean liquid. This outflow channel can play a blocking role to prevent the unfiltered waste liquid in the drum 2 from being mixed into the fully filtered clean liquid. Further, the outflow channel is communicated with the liquid discharge port 11 located at the top of the filtering cavity 1, so that the liquid discharged from the liquid discharge port 11 flows out in an overflow manner, which can prevent sediment from being mixed into the output clean liquid.

[0039] Refer to Figure 2 , the process of treating waste liquid using the circulating filtration device of this embodiment is as follows:

[0040] Use a liquid extraction pump to pump the waste liquid from the storage tank of the developing solution or the film stripping solution to the circulating filtration equipment. Start the motor 81 in the circulating filtration equipment. The motor 81 drives the drum 2 to rotate at a set high speed. When the drum 2 rotates, a strong centrifugal force is generated. Since the specific gravities of the solids and liquids in the waste liquid are different, the centrifugal forces they receive are different. Therefore, impurities such as ink, dry film residues, and colloids in the waste liquid will be thrown onto the inner wall of the drum 2. After the filter residue accumulates to a certain thickness, start the scraping function of the scraper 3, which can scrape off the filter residue on the inner wall of the drum 2 and discharge it outward through the slag discharge port. The clean liquid can then flow back to the intermediate tank or the chemical tank through the liquid outlet for recycling, so as to achieve the filtration and circulation of the developing solution or the film stripping solution.

[0041] In summary, the circulating filtration equipment of this embodiment has the following beneficial effects:

[0042] Realize solid-liquid separation: This circulating filtration equipment adopts the centrifugal cross-flow separation treatment technology, and realizes pure physical non-clogging solid-liquid separation through centrifugation, thoroughly filtering fine ink residues and dry film residues, and then separately outputting the filter residue and the clean liquid outward.

[0043] Extend the service life of the chemical solution: 100% of the developing solution can be recycled. The service life of the sodium carbonate system of the developing solution can be extended to 7 - 10 days for discharge, and the potassium carbonate system can be extended to 10 - 15 days for discharge, reducing downtime, maintenance labor, and the consumption of the chemical solution, and easily solving the environmental protection discharge problem.

[0044] Reduce the amount and cost of sewage treatment: Adopting the centrifugal cross-flow separation treatment technology, compared with the cotton core filtration method, it can effectively reduce the amount of waste liquid treatment and the cost of waste liquid treatment, reduce the COD (chemical oxygen demand) value in the discharged sewage, meet the national discharge standards, and greatly reduce the pressure on the sewage treatment station to treat organic wastewater.

[0045] Reduce the tank changing time and maintenance cycle: By setting a reasonable rotation speed, the drum can generate a strong centrifugal force (which can reach 1700 times the gravity of the impurities' own weight), improving the filtration accuracy, solving the problems of poor filtration effect with the traditional cotton core filtration, and quality problems such as nozzle blockage, uneven development, and residue re-adhesion to the board surface when the filtered clean liquid is recycled. The utility model can reduce the tank changing time of the developing tank and the film stripping tank; at the same time, the equipment uses pure physical separation without any foreign substances intervening, improving the cleanliness of the recycled liquid, making the components in contact with the recycled liquid such as the tank body and rollers not easily contaminated, and the nozzle not easily blocked, which can extend the maintenance time and reduce the maintenance frequency.

[0046] Increase the equipment utilization rate and production capacity: Reduce the maintenance labor, increase the equipment utilization rate, and thus increase the production capacity.

[0047] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A circulating filtration device for PCB manufacturing waste liquid, characterized in that, It includes a filtration cavity, a rotating mechanism, a drum, a scraper, and a liquid inlet for inputting waste liquid; the drum is located inside the filtration cavity, the drum is in transmission connection with the rotating mechanism, and the rotating mechanism can drive the drum to rotate; The drum is of a hollow structure, the liquid inlet is communicated with the inside of the drum, the scraper extends into the inside of the drum and abuts against the inner wall of the drum to scrape off the filter residue adsorbed on the inner wall of the drum; The filtration cavity is provided with a liquid outlet for discharging clean liquid and a slag discharge port for discharging filter residue.

2. The cyclic filtration device according to claim 1, wherein There is a first gap between the outer side surface of the drum and the inner wall of the filtration cavity, and a second gap between the bottom wall of the drum and the bottom wall of the filtration cavity. The first gap and the second gap together serve as the outflow channel for clean liquid; The outflow channel is communicated with the liquid outlet.

3. The circulating filtration device according to claim 1, characterized in that The liquid outlet is located at the top position of the filtration cavity; the slag discharge port is located at the bottom position of the filtration cavity.

4. The circulation filtration device according to claim 1, characterized in that, The drum is of a hollow cylindrical structure.

5. The circulation filtration device according to claim 1, wherein, It further includes a top cover. The top end of the filtration cavity is an open end, and the top cover covers the opening at the top end of the filtration cavity. The liquid inlet is arranged on the top cover.

6. The circulation filtration device according to claim 5, characterized in that, It further includes a scraper mounting rod. The top end of the scraper mounting rod is fixedly connected to the top cover, and its bottom end is fixedly connected to the scraper.

7. The circulating filtration device according to claim 1, wherein The rotating mechanism includes a motor, a belt pulley transmission assembly, and a rotating shaft. The motor is in transmission connection with the bottom end of the rotating shaft through the belt pulley transmission assembly. The top end of the rotating shaft is fixedly connected to the drum, and the motor can drive the drum to rotate at a set speed.

8. The circulating filtration device according to claim 7, characterized in that, The peripheral edge of the top end of the rotating shaft is fixedly connected to the inner wall of the drum through spokes.

9. The circulation filtration device according to claim 8, characterized in that, The top of the rotating shaft is provided with a spoke mounting portion. The diameter of the spoke mounting portion is larger than the diameter of the rotating shaft. A plurality of the spokes are fixed on the outer peripheral edge of the spoke mounting portion and are circumferentially and separately distributed along the spoke mounting portion.

10. The circulating filtration device according to claim 1, characterized in that, It further includes a bottom box. The filtration cavity is fixed on the bottom box, and the rotating mechanism is installed inside the bottom box.

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