A sequential trap

Abstract

The utility model discloses a kind of in-sequence relay type trappers, it is related to sintering furnace technical field, including trapper main body one, trapper main body two, bypass pipeline one and bypass pipeline two, trapper main body one and trapper main body two head end are provided with main air inlet one and main air inlet two, trapper main body one and trapper main body two are provided with several bypass air inlet one and bypass air inlet two along pipeline length direction, several bypass valves one are provided on bypass pipeline one, bypass valve one is used for controlling the on-off between bypass pipeline one and the pipeline of trapper main body one at its location, several bypass valves two are provided on bypass pipeline two, bypass valve two is used for controlling the on-off between bypass pipeline two and the pipeline of trapper main body two at its location;The utility model can greatly improve trapping rate, lengthen cleaning interval period of trapper, lengthen pump oil replacement cycle, lengthen pump cleaning maintenance cycle, improve the performance of sintered part.

Description

Technical Field

[0001] This utility model relates to the field of sintering furnace technology, and in particular to a sequential relay-type trap. Background Technology

[0002] The role of adhesives in MIM: The binder and metal powder are mixed to form a flowable feedstock. The viscosity and rheological properties of the binder allow the mixture to be injected into the mold under high pressure during the injection molding stage, filling complex cavities. This enables the molding of high-precision, complex shapes. The injection-molded part is called a "green preform".

[0003] Approximately 90% of the binder is decomposed and discharged in the acid debinding furnace, while about 10% of the binder maintains the state of the model. The part at this stage is called the "brown blank". The "brown blank" undergoes further binder removal and high-temperature sintering in a metal injection molding vacuum debinding and sintering furnace.

[0004] How is the binder removed in a vacuum debinding and sintering furnace during metal injection molding? Under negative pressure degreasing, the furnace is heated to the temperature at which the binder vaporizes and decomposes. Inert protective carrier gas is introduced into the furnace. The material box is connected to the degreasing pipe, and the pump draws a vacuum, allowing the gas to flow in one direction. The pressure inside the furnace, P1, is greater than the pressure inside the material box, P2. The binder vapor and decomposition products in the material box flow into the degreasing pipe along with the inert protective carrier gas. Some of the gas encounters the pipe wall, cools, and turns into liquid, flowing into the collection box. The gas that does not turn into liquid continues to flow through the collection box and reaches the collection pipe. The collection pipe has a collector, which is filled with cooling water and has multiple layers of fins to obstruct the flow, causing the gas to liquefy or even solidify upon cooling.

[0005] Decomposition conditions and products of adhesives: The remaining binder is vaporized and decomposed at high temperature in a metal injection molding vacuum debinding and sintering furnace. The main decomposition products include: hydrocarbon gases (methane, ethane, etc.), oxygen-containing organic compounds (ethylene glycol, carbon dioxide, etc.), carbon residue (partial carbonization may occur due to incomplete removal of polymer molecules, affecting material properties), and other small molecule gases (carbon monoxide, hydrogen, etc.).

[0006] Why do adhesives trap substances? 1. Pollutes the environment; 2. Pollutes pump oil, increasing oil change costs; 3. Causes carbon residue, affecting product performance, such as reducing the corrosion resistance of stainless steel.

[0007] Introduction to traditional cold-well finned traps: The original collector was a cold-well type, with circulating cooling water. The fins were welded to the cooling water pipes, keeping the fin temperature relatively low. Adhesive vapor flowed through the collector along with the inert protective carrier gas. The fins were layered and bent left and right, causing the gas to flow in an S-shaped pattern. Adhesive vapor and decomposition products collided with the fins, cooling water pipes, and the inner wall of the collector, condensing into liquid upon cooling and then solidifying. A small portion of the uncondensed liquid flowed out through the square holes at the bottom of the fins into the grease collection box. The fins were in a series structure; the more fins, the greater the airflow path and the larger the collision area. The main grease-catching principle relied on multiple layers of fins to increase the airflow path and the collision area between the airflow and the cooling pipes and fins.

[0008] Conditions required for the capture of binder vapors and decomposition products: The gas concentration and temperature required for condensation or liquefaction.

[0009] The current problems with capture: If the airflow channel is too large, the contact between the binder and the condenser will be greatly reduced, making it more difficult to achieve the required concentration and temperature for condensation. The binder will fail to be captured and will be directly drawn away. If the channel is too small, the binder will condense quickly and accumulate in the channel, clogging the pipes and affecting the subsequent discharge of the continuously decomposing binder. If the cooling effect is too good, the binder will accumulate and clog the pipes. If the cooling effect is too poor, the temperature will not reach the condensation requirements, and the binder will fail to be captured. In summary: either the binder cannot be captured, or if it is captured, it will clog. Currently, there is still significant room for improvement in the capture rate.

[0010] During equipment use, the trap should be kept clear of blockages, as blockages will reduce or even shut off the air extraction channel, resulting in incomplete extraction of decomposition products. A large amount of polymer will remain in the sintered parts as carbon residues, which will affect their performance.

[0011] In summary, a sequential relay trap is provided that can improve the capture rate while preventing channel blockage. Utility Model Content

[0012] The purpose of this invention is to provide a sequential relay trap to solve the problems existing in the prior art, which can significantly improve the trapping rate, extend the cleaning interval of the trap, extend the pump oil replacement cycle, extend the pump cleaning and maintenance cycle, and improve the performance of sintered parts.

[0013] To achieve the above objectives, this utility model provides the following solution: This utility model provides a sequential relay-type trap, including a trap body one, a trap body two, a bypass pipe one, and a bypass pipe two. The trap body one and the trap body two are respectively provided at their front ends with a main air inlet one and a main air inlet two. Along the length of the pipes, the trap body one and the trap body two are also respectively provided with a plurality of bypass air inlets one and two. Corresponding to each bypass air inlet one, a plurality of bypass valves one are provided on the bypass pipe one. The bypass valves one are used to control the connection between the bypass pipe one and the pipe of the trap body one at their respective locations. The bypass pipe two is provided with a plurality of bypass valves one corresponding to each bypass air inlet one. Each bypass inlet 2 is equipped with several bypass valves 2, which are used to control the connection and disconnection between the bypass pipe 2 at its location and the pipe of the trap body 2; the first end of the bypass pipe 1 and the bypass pipe 2 is provided with an adhesive vapor inlet pipe connected to it, and the first end of the bypass pipe 1 and the bypass pipe 2 is also connected to the main inlet 1 and the main inlet 2 respectively through the main inlet pipe 1 and the main inlet pipe 2; the tail end of the trap body 1 and the trap body 2 is provided with exhaust gas outlet 1 and exhaust gas outlet 2, and exhaust valve 1 and exhaust valve 2 are respectively provided at exhaust gas outlet 1 and exhaust gas outlet 2.

[0014] Preferably, both the first and second bodies of the trap are equipped with pressure sensors for detecting the pressure inside the trap pipe.

[0015] Preferably, a pressure sensor for detecting the pressure inside the trap pipe is provided at the front end of both the trap body one and the trap body two.

[0016] Preferably, a cooling water pipe is provided at the center of the first and second bodies of the trap, and fins are distributed on the cooling water pipe.

[0017] Preferably, the tail ends of the bypass pipe one and bypass pipe two are sealed structures.

[0018] Preferably, the two ends of the adhesive vapor inlet pipe are respectively connected to the beginning ends of the bypass pipe one and the bypass pipe two, and the middle part of the adhesive vapor inlet pipe is connected to the adhesive vapor delivery pipe.

[0019] Preferably, an exhaust pipe connects the exhaust outlet one and the exhaust outlet two, and a vacuum pump is connected to the middle of the exhaust pipe via a pipeline. The exhaust valve one is disposed on the exhaust pipe and is located near the trap body one, and the exhaust valve two is disposed on the exhaust pipe and is located near the trap body two.

[0020] The present invention achieves the following technical advantages over the prior art: The sequential relay-type trap in this invention operates in a relay manner. After the adhesive clogs one trapping point or the channel narrows to its lower limit, another trapping channel is quickly opened. Multiple trapping channels are connected in parallel, with bypass valves between channels acting like relay batons. This significantly improves the trapping rate, extends the cleaning interval of the trap, lengthens the pump oil replacement cycle, extends the pump cleaning and maintenance cycle, and enhances the performance of sintered components. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the sequential relay trap in this utility model; Figure 2 This is a schematic diagram of the working process of the sequential relay trap in this utility model; In the diagram: 1. Main body of the trap; 2. Main body of the trap; 3. Bypass pipe 1; 4. Bypass pipe 2; 5. Main air inlet 1; 6. Main air inlet 2; 7. Bypass air inlet 1; 8. Bypass air inlet 2; 9. Bypass valve 1; 10. Bypass valve 2; 11. Adhesive vapor inlet pipe; 12. Main air inlet pipe 1; 13. Main air inlet pipe 2; 14. Exhaust outlet 1; 15. Exhaust outlet 2; 16. Exhaust valve 1; 17. Exhaust valve 2; 18. Fins; 19. Cooling water pipe; 20. Adhesive vapor delivery pipe; 21. Exhaust pipe. Detailed Implementation

[0023] 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.

[0024] The purpose of this invention is to provide a sequential relay trap to solve the problems existing in the prior art.

[0025] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] The sequential relay trap in this embodiment, such as Figure 1As shown, the device includes a trap body 1, a trap body 2, a bypass pipe 3, and a bypass pipe 4. The trap body 1 and the trap body 2 are respectively equipped with a main air inlet 5 and a main air inlet 6 at their ends. Along the length of the pipes, the trap body 1 and the trap body 2 are also equipped with several bypass air inlets 7 and 8. The bypass pipe 3 is equipped with several bypass valves 9 corresponding to each bypass air inlet 7. The bypass valves 9 are used to control the connection between the bypass pipe 3 and the trap body 1 at their respective locations. The bypass pipe 4 is equipped with several bypass valves 9 corresponding to each bypass air inlet 8. Bypass valve 2 10 is used to control the connection and disconnection between the bypass pipe 2 4 and the trap body 2 2 at its location; the first ends of the bypass pipe 1 3 and the bypass pipe 2 4 are provided with adhesive vapor inlet pipe 11 connected to them; the first ends of the bypass pipe 1 3 and the bypass pipe 2 4 are also connected to the main inlet 1 5 and the main inlet 2 6 respectively through the main inlet pipe 1 12 and the main inlet pipe 2 13; the tail ends of the trap body 1 1 and the trap body 2 2 are provided with tail gas outlet 1 14 and tail gas outlet 2 15, and exhaust valve 1 16 and exhaust valve 2 17 are respectively provided at tail gas outlet 1 14 and tail gas outlet 2 15.

[0027] In this specific embodiment, both the trap body 1 and the trap body 2 are equipped with pressure sensors for detecting the pressure inside the trap pipe. Alternatively, a pressure sensor for detecting the pressure inside the trap pipe is installed at the front end of both the trap body 1 and the trap body 2, specifically on the adhesive vapor conveying pipe 20.

[0028] In this specific embodiment, a cooling water pipe 19 is provided at the center of the trap body 1 and the trap body 2, and fins 18 are distributed on the cooling water pipe 19, and circulating cooling water flows through the cooling water pipe 19.

[0029] In this specific embodiment, the tail ends of bypass pipe 3 and bypass pipe 4 are sealed structures.

[0030] In this specific embodiment, the two ends of the adhesive vapor inlet pipe 11 are respectively connected to the beginning ends of the bypass pipe 3 and the bypass pipe 4, and the middle part of the adhesive vapor inlet pipe 11 is connected to the adhesive vapor delivery pipe 20.

[0031] In this specific embodiment, an exhaust pipe 21 is connected between exhaust outlet 14 and exhaust outlet 15. The middle part of the exhaust pipe 21 is connected to a vacuum pump through a pipeline. Exhaust valve 16 is set on the exhaust pipe 21 and is located near the collector body 1. Exhaust valve 27 is set on the exhaust pipe 21 and is located near the collector body 2.

[0032] The sequential relay trap of this utility model works as follows: like Figure 2 As shown, in the initial state, all bypass valves 1-9 and 2-10 are closed, and the outlet valve 16 is opened. The airflow is drawn away from the pipe of the trap body 1, and the channel gradually narrows, even becoming blocked (the scrambled lines in the diagram indicate the blockage location). After the system detects the blockage, it will open the bypass valves 1-9 sequentially from front to back until the system determines that the channel is clear. If the channel is clear only after the third bypass valve 1-9 is opened, then the other bypass valves 1-9 after the third bypass valve 1-9 will not be opened, allowing the binder vapor to pass only through the trap channel.

[0033] When almost all sections of the pipes in trap body 1 are blocked, close vent valve 16 and open vent valve 17 to open the pipes in trap body 2. The trapping process in trap body 2 is the same as that in trap body 1. At this time, the pipes in trap body 1 are cleaned by heating wires on the pipe walls to melt the adhesive inside the pipes, allowing for reuse and enabling the two trap bodies to be used alternately.

[0034] The method for determining pipe blockage is as follows: Before blockage, the furnace pressure P1 > the material box pressure P2, P1 - P2 = ΔP. With a constant airflow rate, if the exhaust channel narrows, P1 will increase, and ΔP will decrease. The change in ΔP is used to determine the change in channel size, serving as a channel switching signal. Alternatively, P1 can be used as the switching signal. When ΔP or P1 reaches a set value, it indicates a channel blockage, triggering the opening of bypass valve 9 or bypass valve 10 until the pressure returns to normal. The instruction manual states that opening bypass valve 9 or bypass valve 10 avoids the blockage location.

[0035] The sequential relay-type trap works in a relay fashion. When the binder becomes clogged at one trapping point or the channel narrows to its lower limit, another trapping channel quickly opens. Multiple trapping channels are connected in parallel, with valves between channels acting like relay batons. This significantly improves the trapping rate, extends the trapping interval, extends the pump oil change cycle, extends the pump cleaning and maintenance cycle, and improves the performance of sintered components. It should be noted that the number of trapping channels, shut-off valves, bypass valves, the number of fins between bypass valves, and the number of pressure sensors are all unlimited and can be adjusted according to actual operating conditions.

[0036] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A sequential trap catcher characterized by: The system includes a trap body 1, a trap body 2, a bypass pipe 1, and a bypass pipe 2. The trap body 1 and the trap body 2 are respectively provided with a main air inlet 1 and a main air inlet 2 at their respective ends. Along the length of the pipes, the trap body 1 and the trap body 2 are also provided with a plurality of bypass air inlets 1 and 2. The bypass pipe 1 is provided with a plurality of bypass valves 1 corresponding to each bypass air inlet 1. Each bypass valve 1 is used to control the connection between the bypass pipe 1 and the trap body 1 at its location. The bypass pipe 2 is provided with a bypass valve 2 corresponding to each bypass air inlet 2. Several bypass valves are provided, which are used to control the connection and disconnection between the bypass pipe and the main body of the trap at their respective locations. The first ends of the bypass pipe and the bypass pipe are provided with adhesive vapor inlet pipes connected to them. The first ends of the bypass pipe and the bypass pipe are also connected to the main inlet and the main inlet, respectively, through the main inlet pipe and the main inlet pipe. The tail ends of the trap body and the trap body are provided with exhaust outlet and exhaust outlet, respectively. Exhaust valve and exhaust valve are provided at exhaust outlet and exhaust outlet, respectively.

2. The sequential trap collector of claim 1, wherein: Both the first and second bodies of the trap are equipped with pressure sensors for detecting the pressure inside the trap pipes.

3. The sequential trap harvester of claim 1, wherein: A pressure sensor for detecting the pressure inside the trap pipe is provided at the front end of both the trap body one and the trap body two.

4. The sequential trap harvester of claim 1, wherein: Cooling water pipes are provided at the center of the first and second bodies of the trap, and fins are distributed on the cooling water pipes.

5. The sequential trap harvester of claim 1, wherein: The ends of the bypass pipe one and bypass pipe two are sealed structures.

6. The sequential sprinter trap of claim 1, wherein: The two ends of the adhesive vapor inlet pipe are respectively connected to the beginning ends of the bypass pipe one and the bypass pipe two, and the middle part of the adhesive vapor inlet pipe is connected to the adhesive vapor delivery pipe.

7. The sequential sprinter trap of claim 1, wherein: An exhaust pipe connects the exhaust outlet one and the exhaust outlet two. A vacuum pump is connected to the middle of the exhaust pipe via a pipeline. Exhaust valve one is located on the exhaust pipe and close to the main body of the trap. Exhaust valve two is located on the exhaust pipe and close to the main body of the trap.

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