Drum-type circuit board detinning device

Abstract

The utility model belongs to the related technical field of circuit board detinning, and particularly relates to a drum-type circuit board detinning device. The drum-type circuit board detinning device comprises a rotary drum body, a feeding part and a heating part, the rotary drum body sequentially comprises a temperature rise section used for heating a circuit board to raise the temperature of the circuit board, a separation section used for tin soldering and element discharging and a tailing section used for substrate discharging, and shoveling plates are arranged on the inner walls of the temperature rise section and the separation section; the wall face of the separation section is provided with a hole channel for soldering tin and elements to pass through, and a first discharging opening is formed in the lower portion of the separation section. And the tailing section is communicated with a second discharge port. According to the utility model, the circuit board is temporarily clamped by the shoveling plate of the temperature rise section, so that the distribution uniformity of the circuit board in the rotary drum body is improved, the circuit board is stirred by the shoveling plate of the separation section, and the heating uniformity of the circuit board in the rotary drum can be improved and the separation efficiency between soldering tin and a substrate is also improved in cooperation with a mode of simultaneously heating inside and outside.

Description

Technical Field

[0001] This utility model belongs to the technical field of circuit board desoldering, and specifically relates to a roller-type circuit board desoldering device. Background Technology

[0002] Currently, the most common desoldering process for waste circuit boards is still manual soldering. Workers immerse the circuit boards in desoldering solution and manually shake them to separate the components. This method is inefficient and labor-intensive. Automated desoldering devices are also available, typically using drums as the desoldering space and heating the material with electricity or gas. The drawback of drum-type circuit board desoldering devices is that uneven heating within the furnace can lead to incomplete desoldering and even thermal decomposition of some components.

[0003] To address the aforementioned technical problems, Chinese patent document CN216065914U discloses a circuit board desoldering device to solve the issues of uneven heating and wasted heat resources in current desoldering machines. This circuit board desoldering device includes a chassis, inside which a rotating drum with perforated screens is mounted. A heat transfer tube with air vents is fixed inside the drum. A heater is located on one side of the chassis, with its heating element extending into the heat transfer tube. This design places the heat transfer tube at the center of the drum within the chassis, ensuring uniform heat distribution within the chassis. Furthermore, the heating source being located inside the drum improves heat transfer efficiency, thereby increasing desoldering efficiency.

[0004] In addition to removing solder from the circuit board, circuit board desoldering also aims to effectively separate the solder from electronic components and the substrate. To address the problem of incomplete separation of solder and electronic components in existing methods, Chinese patent document CN212285266U discloses a device for desoldering circuit boards and separating electronic components. This device includes a receiving hopper, an externally heated rotary kiln, a cooling system, and a separation chamber. The receiving hopper is connected to the kiln cylinder of the externally heated rotary kiln. The separation chamber contains a drum screen, a vibrating screen, and a collection trough, arranged sequentially from top to bottom. The collection trough has a discharge port at its lower end. The kiln tail hood of the externally heated rotary kiln is connected to the drum screen via a first chute. The cooling system includes cooling water pipes and a cooling water circulation device, with the cooling water pipes surrounding the outer circumference of the first chute. This method first heats the circuit board to 250-500°C in the externally heated rotary kiln, then guides it to the drum screen for effective separation of solder, substrate, and electronic components.

[0005] Therefore, improving the heat uniformity of the circuit board inside the drum and the solder separation efficiency are two important considerations when evaluating a circuit board desoldering device. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a roller-type circuit board desoldering device to improve the heating uniformity of the circuit board in the roller and the separation efficiency between the solder and the substrate.

[0007] The solution of this utility model to the aforementioned technical problem is as follows:

[0008] Roller-type circuit board desoldering device, including

[0009] A rotating cylinder for housing circuit boards, equipped with a rotation drive mechanism;

[0010] The feeding component is used to feed the circuit board into the interior of the rotating cylinder;

[0011] Heating components are used to heat the cylinder, causing the solder on the circuit board to melt inside the cylinder.

[0012] The rotating cylinder sequentially includes a temperature rise section for heating the circuit board to raise its temperature, a separation section for soldering and component discharge, and a tail section for substrate discharge. The inner walls of the temperature rise section and the separation section are provided with lifting plates.

[0013] The wall of the separation section has channels for solder and components to pass through, and a first discharge port is provided at the bottom of the separation section; the tail section is connected to a second discharge port.

[0014] The inventive concept of this application lies in the following: In the solution described in Chinese Patent Document CN216065914U, due to the mass of the circuit board, most of the circuit boards do not rotate with the perforated drum during rotation, resulting in low efficiency in soldering and separation of components from the substrate. The rotating drum of this application mainly includes a temperature rise section and a separation section, both equipped with lifting plates. The circuit board moves laterally and rotates longitudinally within the rotating drum. Furthermore, the circuit board is temporarily secured to the lifting plates in the temperature rise section, making it easy for the circuit board to adhere to the inner wall of the rotating drum. The circuit board secured to the lifting plates can also carry other circuit lines. This method helps improve the uniformity and looseness of the circuit board distribution across the drum cross-section, resulting in more uniform heating and a corresponding increase in the separation efficiency between the solder and the substrate. When the circuit board is rotated to the separation section, as the components on the substrate detach, the circuit board is no longer secured to the lifting plates, which primarily function as material flippers. Furthermore, the molten solder and detached components of this application flow out of the rotating cylinder through the same channel, which facilitates a more thorough separation of the solder from the substrate. After the solder and components exit from the first discharge port, they can be further separated by a vibrating screen after cooling.

[0015] As an improvement, a furnace head hood and a furnace tail hood are respectively provided at both ends of the rotating cylinder. The furnace head hood and the furnace tail hood are rotatably and sealed to the rotating cylinder. The tail section of the rotating cylinder is connected to the furnace tail hood. An internal flue gas outlet is provided on the furnace head hood or the furnace tail hood. The combination of the furnace tail hood, the furnace head hood and the rotating cylinder facilitates the entry and exit of materials and the exit of internal flue gas.

[0016] As a further improvement, the internal flue gas outlet is located at the top of the furnace head hood, and a hot flue gas inlet is provided on the furnace tail hood, so that the direction of travel of the heating flue gas inside the rotating cylinder is opposite to the direction of travel of the circuit board inside the rotating cylinder. This scheme achieves simultaneous heating inside and outside, and also facilitates the timely removal of waste flue gas from inside the rotating cylinder.

[0017] As an improvement, the heating component is a flue gas jacket, which wraps around the temperature rise section and the separation section.

[0018] As a further improvement, the flue gas jacket is provided with at least one hot flue gas inlet in the temperature rise section and at least one hot flue gas inlet in the separation section. The hot flue gas inlet corresponding to the temperature rise section is located at the bottom of the rotating cylinder, and the hot flue gas inlet corresponding to the separation section is located below the central axis of the rotating cylinder. The heated flue gas can enter the interior of the rotating cylinder through the channels of the separation section and directly contact the circuit board. Both the temperature rise section and the separation section are heated by hot flue gas. The hot flue gas inlet of the separation section is located on the side of the rotating cylinder. The heated flue gas entering from the side can fully exchange heat with the internal circuit board, which is beneficial to the separation of solder, components and substrate.

[0019] As a further improvement, the hot flue gas inlet corresponding to the separation section is inclined towards the bottom of the separation section. This design facilitates the removal of solder and components from the channel.

[0020] As an improvement, the flue gas jacket is provided with a windbreak weir at the junction of the temperature rise section and the separation section, so that the heated flue gas entering from the corresponding hot flue gas inlet of the temperature rise section flows around the outer circumference of the temperature rise section.

[0021] As an alternative, the heating element is an electric heating wire wrapped around the temperature rise section.

[0022] As an improvement, the feeding component includes a horizontally arranged feeding cylinder, a feeding bin arranged perpendicular to the feeding cylinder, and a hydraulic push rod located at one end of the feeding cylinder; the feeding cylinder extends into the interior of the rotating cylinder. Compared with a feeding chute, this feeding method is more controllable and achieves intermittent continuous feeding.

[0023] As an improvement, the feed hopper is equipped with two layers of gate valves, and both the first and second discharge ports are equipped with two layers of gate valves. The two layers of gate valves effectively isolate the external and internal spaces, achieving sealed feeding and sealed discharge.

[0024] The beneficial effects of this utility model are as follows: by temporarily engaging the circuit board with the lifting plate in the temperature rise section, the uniformity of the circuit board distribution in the rotating cylinder is improved. The lifting plate in the separation section then stirs the circuit board. Combined with the simultaneous heating inside and outside, the heating uniformity of the circuit board in the drum can be improved, and the separation efficiency between the solder and the substrate is also improved. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0026] Figure 2 This is a structural schematic diagram of Embodiment 2 of the present invention.

[0027] In the diagram: 10. Rotating cylinder; 11. Temperature rise section; 12. Separation section; 121. Channel; 122. First discharge port; 13. Tail section; 131. Second discharge port; 14. Internal flue gas outlet; 15. Hot flue gas inlet; 16. Windbreak weir; 20. Feeding component; 21. Feeding cylinder; 22. Feeding bin; 23. Hydraulic push rod; 30. Heating component; 40. Lifting plate; 51. Furnace head hood; 52. Furnace tail hood; 60. Slide valve. Detailed Implementation Example 1

[0028] like Figure 1 As shown, the roller-type circuit board desoldering device of this application includes a rotating cylinder 10, a feeding component 20, and a heating component 30. The rotating cylinder 10, equipped with a rotating drive mechanism, is used to house the circuit board, allowing the components to separate after the circuit board is heated inside the rotating cylinder 10. A furnace head cover 51 and a furnace tail cover 52 are respectively provided at both ends of the rotating cylinder 10, and the furnace head cover 51 and furnace tail cover 52 are rotatably and sealingly connected to the rotating cylinder 10.

[0029] The feeding component 20 for feeding circuit boards into the rotating cylinder 10 includes a horizontally arranged feeding cylinder 21, a feeding bin 22 perpendicular to the feeding cylinder 21, and a hydraulic push rod 23 located at one end of the feeding cylinder 21; the feeding cylinder 21 extends into the rotating cylinder 10. The feeding cylinder 21 has a pipe diameter of 500mm, which can meet the feeding requirements of most waste circuit boards. The feeding bin 22 is equipped with two layers of gate valves 60, which can achieve sealed feeding at the feeding end.

[0030] The rotating cylinder 10 sequentially includes a temperature rise section 11 for heating the circuit board, a separation section 12 for solder and component discharge, and a tailing section 13 for substrate discharge. The inner walls of the temperature rise section 11 and the separation section 12 are equipped with lifting plates 40, which are 90° lifting plates without bends. The circuit board is heated to 235℃~250℃ in the temperature rise section 11, causing the solder in the circuit board to melt. Other components only experience a temperature increase without thermal decomposition or other chemical reactions. The wall of the separation section 12 has channels 121 for solder and components to pass through, and a first discharge port 122 is located below the separation section 12; the tailing section 13 is connected to a second discharge port 131. The channels 121 can be square or circular, with a diameter controlled between 4 and 8 cm. Solder and components detach and separate due to internal material disturbance. The molten solder and fallen components pass through the channel 121 and are then discharged through the first discharge port 122. After discharge, further soldering and component separation can be achieved through a vibrating screen. The substrate after desoldering and component removal is discharged through the tail section 13 and then through the second discharge port 131. To increase the residence time of the circuit board in the furnace, the tail section 13 can be equipped with a climbing angle to improve the filling rate of the rotating cylinder 10. Both the first discharge port 122 and the second discharge port 131 are equipped with two layers of gate valves 60 to achieve sealed discharge.

[0031] The heating element 30 for heating the cylinder 10 is a flue gas jacket, which surrounds the temperature rise section 11 and the separation section 12. The distance between the inner wall of the jacket and the outer wall of the rotating cylinder 10 is 300 mm, and the temperature of the heated flue gas is 300℃. The flue gas jacket has two hot flue gas inlets 15 in the temperature rise section 11 and two hot flue gas inlets 15 in the separation section 12. The hot flue gas inlets 15 corresponding to the temperature rise section 11 are located at the bottom of the rotating cylinder 10, and the hot flue gas inlets 15 corresponding to the separation section 12 are located below the central axis of the rotating cylinder 10 and inclined towards the bottom of the separation section 12. The heated flue gas can enter the interior of the rotating cylinder 10 through the channel 121 of the separation section 12 and directly contact the circuit board. A windbreak weir 16 is provided at the junction of the temperature rise section 11 and the separation section 12 in the flue gas jacket, so that the heated flue gas entering from the hot flue gas inlet 15 corresponding to the temperature rise section 11 flows around the outer circumference of the temperature rise section 11.

[0032] The tail section 13 of the rotating cylinder 10 is connected to the furnace tail hood 52. The internal flue gas outlet 14 is located at the top of the furnace head hood 51. A hot flue gas inlet 15 is provided on the furnace tail hood 52, so that the direction of travel of the heating flue gas inside the rotating cylinder 10 is opposite to the direction of travel of the circuit board inside the rotating cylinder 10. The temperature of the flue gas discharged from the internal flue gas outlet 14 is reduced to 180~200℃. After dust removal treatment, part of the discharged flue gas can be used as distribution air into the hot blast stove to save energy consumption. The high-temperature flue gas generated by the hot blast stove enters the flue gas jacket. Example 2

[0033] The difference between Example 2 and Example 1 is as follows: Figure 2 As shown, the heating element 30 is an electric heating wire wrapped around the temperature rise section 11. At this time, the internal flue gas outlet 14 is located at the top of the furnace tail cover 52.

Claims

1. A roller-type circuit board desoldering device, including A rotating cylinder (10) is used to accommodate the circuit board and is equipped with a rotating drive mechanism; The feeding component (20) is used to feed the circuit board into the interior of the rotating cylinder (10); Heating component (30) is used to heat the rotating cylinder (10) so that the solder on the circuit board is heated and melted inside the cylinder (10); Its features are: The rotating cylinder (10) includes, in sequence, a temperature rise section (11) for heating the circuit board to raise its temperature, a separation section (12) for soldering and component discharge, and a tail section (13) for substrate discharge. The inner walls of the temperature rise section (11) and the separation section (12) are provided with lifting plates (40). The wall of the separation section (12) is provided with a channel (121) for solder and components to pass through, and a first discharge port (122) is provided below the separation section (12); the tail section (13) is connected to a second discharge port (131).

2. The drum-type circuit board desmear apparatus as claimed in claim 1, wherein: The rotating cylinder (10) is provided with a furnace head cover (51) and a furnace tail cover (52) at both ends respectively. The furnace head cover (51) and the furnace tail cover (52) are rotatably sealed to the rotating cylinder (10). The tail section (13) of the rotating cylinder (10) is connected to the furnace tail cover (52). An internal flue gas outlet (14) is provided on the furnace head cover (51) or the furnace tail cover (52).

3. The drum-type circuit board desmear apparatus as claimed in claim 2, wherein: The internal flue gas outlet (14) is located at the top of the furnace head cover (51), and the furnace tail cover (52) is provided with a hot flue gas inlet (15), so that the direction of the heating flue gas in the rotating cylinder (10) is opposite to the direction of the circuit board in the rotating cylinder (10).

4. The drum-type circuit board desmear apparatus as claimed in claim 1, wherein: The heating component (30) is a flue gas jacket, which surrounds the temperature rise section (11) and the separation section (12).

5. The drum-type circuit board desmear apparatus as claimed in claim 4, wherein: The flue gas jacket is provided with at least one hot flue gas inlet (15) in the temperature rise section (11) and at least one hot flue gas inlet (15) in the separation section (12). The hot flue gas inlet (15) corresponding to the temperature rise section (11) is located at the bottom of the rotating cylinder (10), and the hot flue gas inlet (15) corresponding to the separation section (12) is located below the central axis of the rotating cylinder (10). The heated flue gas can enter the interior of the rotating cylinder (10) through the channel (121) of the separation section (12) and directly contact the circuit board.

6. The drum-type circuit board desmear apparatus of claim 5, wherein: The hot flue gas inlet (15) corresponding to the separation section (12) is inclined toward the bottom of the separation section (12).

7. The drum-type circuit board desmear apparatus as claimed in claim 5, wherein: The flue gas jacket is provided with a windbreak weir (16) at the junction of the temperature rise section (11) and the separation section (12), so that the heated flue gas entering from the hot flue gas inlet (15) corresponding to the temperature rise section (11) flows around the outer circumference of the temperature rise section (11).

8. The drum-type circuit board desmear apparatus as claimed in claim 1, wherein: The heating element (30) is an electric heating wire wrapped around the temperature rise section (11).

9. The drum-type circuit board desmear apparatus as claimed in claim 1, wherein: The feeding component (20) includes a feed cylinder (21) arranged horizontally, a feed bin (22) arranged perpendicular to the feed cylinder (21), and a hydraulic push rod (23) arranged at one end of the feed cylinder (21); the feed cylinder (21) extends into the interior of the rotating cylinder (10).

10. The drum-type circuit board desmear apparatus of claim 9, wherein: The feeding bin (22) is provided with two layers of plug valves (60), and the first discharge port (122) and the second discharge port (131) are each provided with two layers of plug valves (60).

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