Continuous debinding and sintering integrated furnace using negative pressure process

Abstract

A continuous debinding and sintering integrated furnace using a negative pressure process, said furnace comprising a sintering feeding hermetic mechanism (1), a debinding furnace section (2), a sintering furnace section (4), a water cooling section (5) and a sintering discharging hermetic mechanism (6). The sintering feeding hermetic mechanism (1) is configured for hermetic feeding of a material in a carrying box (10) that has been subjected to debinding in a catalytic debinding continuous furnace. The debinding furnace section (2) is configured to perform high-temperature debinding on the material in the transported carrying box (10) and, by means of a wax collection device (3) provided on a side portion of the debinding furnace section (2), collect wax formed by condensation of the material in the carrying box (10) after debinding and sublimation. The sintering furnace section (4) is configured to perform high-temperature sintering on the material in the transported carrying box (10). The water cooling section (5) is configured to cool the material in the transported carrying box (10). The sintering discharging hermetic mechanism (6) is configured for hermetic discharging of the sintered material in the carrying box (10). During the operating process of the continuous debinding and sintering integrated furnace using a negative pressure process, argon is injected therein, and oxygen is completely prevented from entering the furnace, thereby ensuring the efficiency and safety of reactions inside the furnace.

Description

Continuous degumming and sintering integrated furnace using negative pressure process

[0001] This application claims priority to Chinese Patent Application No. 202410514640.8, filed with the Chinese Patent Office on April 26, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of continuous degumming and sintering integrated furnace technology, for example, to a continuous degumming and sintering integrated furnace using a negative pressure process. Background Technology

[0003] Metal Powder Injection Molding Technology (MIM) is a molding method that injects a plasticized mixture of metal powder and its binder into a mold. It involves mixing the selected powder with the binder, granulating the mixture, and then injecting it into the desired shape. The MIM process combines the flexibility of injection molding design with the high strength and integrity of precision metals to achieve low-cost solutions for extremely complex geometries.

[0004] The MIM (Metal Injection Molding) process consists of four unique processing steps: mixing and internal mixing, injection molding, catalytic degreasing, and debinding sintering to produce parts. Surface treatment is then required depending on the product characteristics. Related technologies mainly include two types of continuous debinding sintering furnaces: a pusher-type continuous debinding sintering furnace and a walking beam type. The difference between these two furnaces lies in the movement of the boat plates within the furnace. The pusher-type furnace uses a pusher head to propel the boat plates forward, while the walking beam type uses a raising-forward-lowering-reverse motion to move the boat plates forward step by step. Both continuous lines use ceramic + multi-layer lightweight insulating bricks to insulate against heat in the high-temperature section. To facilitate maintenance of the heating wires and insulation materials, a top cover design (i.e., furnace top lifting) is used. This design can lead to poor sealing in the high-temperature sintering zone. Therefore, both furnaces require the introduction of hydrogen to react with oxygen, achieving oxygen control, preventing product oxidation, and meeting sintering requirements. However, since hydrogen gas in the furnace cavity reacts with carbon at high temperatures, the following disadvantages exist: (1) Hydrogen is a flammable gas, so it is unsafe to pass hydrogen gas through the furnace; (2) Carbon in some products reacts with hydrogen to form methane gas, resulting in a lower carbon content in the products, which limits the application range of the continuous furnace. Summary of the Invention

[0005] This application provides a continuous degumming and sintering integrated furnace using a negative pressure process. During operation, the furnace is filled with argon gas instead of hydrogen gas as in related technologies, which has the advantages of good safety and wide application range.

[0006] A continuous degumming and sintering integrated furnace employing a negative pressure process includes:

[0007] The system includes a sintering feeding airtight mechanism, a degumming furnace section, a sintering furnace section, a water-cooling section, and a sintering discharging airtight mechanism for the passage of a carrier box. The sintering feeding airtight mechanism is configured to provide airtight feeding of the degreased material into the carrier box; the degumming furnace section is configured to perform high-temperature degumming on the material transported from the carrier box; the sintering furnace section is configured to perform high-temperature sintering on the material transported from the carrier box; the water-cooling section is configured to cool the material transported from the carrier box; and the sintering discharging airtight mechanism is configured to provide airtight discharging of the sintered material from the carrier box.

[0008] The continuous degumming and sintering integrated furnace employing negative pressure technology undergoes vacuuming and argon filling operations, ensuring airtight filling of argon gas from the end of the water-cooling section to the beginning of the degumming furnace section. The sintering feeding airtight mechanism and the sintering discharging airtight mechanism, through vacuuming and argon filling operations, prevent air from entering the continuous degumming and sintering integrated furnace when the carrier box enters the degumming furnace section and exits from the water-cooling section, and ensure that the negative pressure inside the continuous degumming and sintering integrated furnace remains stable.

[0009] The feed end of the continuous degumming and sintering integrated furnace using negative pressure technology is connected to the degreasing discharge end of the catalytic degreasing continuous furnace via a horizontal push section.

[0010] In some embodiments, the sintering feeding airtight mechanism consists of two airtight chambers with three sealed hanging doors and a corresponding propulsion structure. The propulsion structure pushes the tray at the bottom of the carrier box and opens the corresponding sealed hanging door. In conjunction with the vacuuming and argon filling actions, the carrier box prevents air from entering the continuous degumming sintering integrated furnace.

[0011] In some embodiments, the sintering feed airtight mechanism includes a first airtight chamber, a first sealed lifting door, a first propulsion structure, a third propulsion structure, a second airtight chamber, a second sealed lifting door, a third sealed lifting door, a first buffer connecting chamber, and a second propulsion structure; the first propulsion structure is located at the tail of the transverse push section and is arranged perpendicular to the transport direction of the carrier box; the first airtight chamber is located in front of the lifting head of the first propulsion structure, and the first sealed lifting door is disposed at the inlet end of the first airtight chamber; the second propulsion structure is disposed on the side of the first airtight chamber and is arranged perpendicular to the first propulsion structure; the second sealed lifting door is disposed at the outlet end of the first airtight chamber and is connected to the second airtight chamber; the third propulsion structure is disposed on the side of the second airtight chamber and is arranged parallel to the first propulsion structure; the third sealed lifting door is disposed at the outlet end of the second airtight chamber and is connected to the first buffer connecting chamber, and the first buffer connecting chamber is connected to the inlet of the degumming furnace section.

[0012] In some embodiments, the first airtight chamber and the second airtight chamber are provided with guide rails for the carrier box to move forward, and the first propulsion structure, the second propulsion structure and the third propulsion structure all move forward by pushing the side of the tray at the bottom of the carrier box.

[0013] In some embodiments, the first airtight chamber, the second airtight chamber, and the first buffer connecting chamber are all provided with transparent observation windows, and a first stainless steel corrugated pipe is provided in the channel between the first buffer connecting chamber and the inlet of the degumming furnace section.

[0014] In some embodiments, a wax collecting device is provided on the side of the degumming furnace section. The wax collecting device is configured to collect the wax oil formed by the degumming and sublimation of the material in the carrier box and then condensing it.

[0015] In some embodiments, the wax collection device comprises a main pipeline connected to the degumming furnace section, a vacuum pump assembly connected to two branch pipelines at the end of the main pipeline, and a wax collection box, wherein a condenser is provided between the top of the wax collection box and the vacuum pump assembly.

[0016] In some embodiments, the degumming furnace section is composed of a multi-zone structure from the beginning to the end. Each zone of the degumming furnace section is provided with an electric heating wire for heating the inner furnace wall of the degumming furnace section. The electric heating wire is installed between the inner furnace wall and the outer furnace of the degumming furnace. A first heat insulation layer supported by a first support frame is provided between the electric heating wire and the outer furnace of the degumming furnace. The heating temperature of the electric heating wire in the multi-zone structure gradually increases.

[0017] In some embodiments, the sintering furnace section includes a graphite heater for heating the inner wall of the sintering furnace section, a heat insulation layer disposed outside the graphite heater, a second heat insulation layer disposed outside the heat insulation layer, and a sintering furnace shell disposed outside the second heat insulation layer; wherein: the sintering furnace shell is provided with through holes for pipelines for connecting electrodes on the graphite heater to pass through; the graphite heater is disposed between the inner wall supported by the second support frame and the sintering furnace shell; the sintering furnace section has a multi-segment structure, and the temperature of the multiple graphite heaters in the multiple sintering furnace sections increases sequentially from the starting end to the end end.

[0018] In some embodiments, two adjacent sintering furnace sections are connected by a flange with a second stainless steel bellows, the second stainless steel bellows being provided with a shrinkage constraint locking rod structure; the bottom of each sintering furnace section is slidably fitted onto a base via a bracket, the bracket and the slide rail on the base being slidably fitted by a slider, the bottom of the bracket being also fitted with a screw nut that cooperates with a ball screw, the end of the ball screw being provided with a wheel, the sintering furnace section being moved laterally along the slide rail by rotating the wheel.

[0019] In some embodiments, the water-cooling section is a multi-segment structure, and the water-cooling section is connected to the sintering discharge airtight mechanism through a third stainless steel corrugated pipe; each water-cooling section is provided with a placement rack at the bottom, and a water-cooling layer is provided inside the water-cooling section to wrap the inner furnace wall of the water-cooling section. A circulating water inlet pipe and a circulating water outlet pipe are connected to the water-cooling layer, and the water-cooling layer is fixed between the outer shell of the water-cooling section and the inner furnace wall through a third support frame.

[0020] In some embodiments, the sintering discharge airtight mechanism consists of two airtight chambers with three sealed hanging doors and a corresponding propulsion structure. The propulsion structure pushes the tray at the bottom of the carrier box (10) and opens the corresponding sealed hanging door, and cooperates with the vacuuming and argon filling actions to achieve airtight discharge.

[0021] In some embodiments, the sintering discharge airtight mechanism includes a second buffer connecting chamber, a fourth sealed lifting door, a fifth sealed lifting door, a third airtight chamber, a fourth airtight chamber, a sixth sealed lifting door, a fourth propulsion structure, a fifth propulsion structure, a sixth propulsion structure, and a seventh propulsion structure; wherein, the fourth propulsion structure is located at the tail end of the water-cooling section and is arranged perpendicular to the transport direction of the carrier box; the second buffer connecting chamber is located in front of the lifting head of the fourth propulsion structure; the third airtight chamber is connected to the second buffer connecting chamber through the fourth sealed lifting door; the fifth propulsion structure is disposed on the side of the third airtight chamber and is arranged perpendicular to the fourth propulsion structure; the fourth airtight chamber is connected to the outlet end of the third airtight chamber through the fifth sealed lifting door; the sixth propulsion structure is disposed on one side of the fourth airtight chamber and is arranged perpendicular to the fifth propulsion structure; the sixth sealed lifting door is disposed at the outlet end of the fourth airtight chamber; the seventh propulsion structure is disposed at the outlet end of the fourth airtight chamber and is configured to propel the side of the bottom tray of the carrier box, and the seventh propulsion structure is arranged perpendicular to the sixth propulsion structure. Attached Figure Description

[0022] Figure 1 is a schematic diagram of the overall structure of a continuous degumming sintering furnace and a catalytic degreasing continuous furnace using a negative pressure process according to an embodiment of this application.

[0023] Figure 2 is a structural schematic diagram of the structure shown in Figure 1 from another direction;

[0024] Figure 3 is a top view of the structure shown in Figure 1;

[0025] Figure 4 is a schematic diagram of the sintering feed airtight mechanism according to an embodiment of this application;

[0026] Figure 5 is a schematic diagram of the internal structure of the degumming furnace section in an embodiment of this application;

[0027] Figure 6 is a schematic diagram of the sintering furnace section according to an embodiment of this application;

[0028] Figure 7 is a schematic diagram of the internal structure of the sintering furnace section in an embodiment of this application;

[0029] Figure 8 is a partial structural diagram of the sintering furnace section according to an embodiment of this application;

[0030] Figure 9 is a structural schematic diagram of the water-cooling section in an embodiment of this application;

[0031] Figure 10 is a schematic diagram of the internal structure of the water-cooled section in an embodiment of this application;

[0032] Figure 11 is a schematic diagram of the sintering discharge airtight mechanism according to an embodiment of this application;

[0033] Figure 12 is a schematic diagram of the guide rail according to an embodiment of this application;

[0034] Figure 13 is a schematic diagram of the graphite heater, electrode, and through hole according to an embodiment of this application;

[0035] Figure 14 is a schematic diagram of the ball screw, screw nut and roller according to an embodiment of this application.

[0036] Reference numerals: 1. Sintering feed airtight mechanism; 101. First airtight chamber; 102. First sealed lifting door; 103. First propulsion structure; 104. Third propulsion structure; 105. Second airtight chamber; 106. Second sealed lifting door; 107. Third sealed lifting door; 108. First buffer connection chamber; 109. First stainless steel corrugated pipe; 110. Second propulsion structure; 111. Guide rail; 112. Transparent observation window; 2. Degumming furnace section; 201. First heat insulation layer; 202. Degumming furnace outer furnace; 203. Electric heating wire; 204. First support frame; 3. Wax collection device; 301. Wax collection box; 302. Vacuum pump set; 4. Sintering Furnace Section; 401. Sintering Furnace Shell; 402. Second Insulation Layer; 403. Second Stainless Steel Corrugated Pipe; 404. Support; 405. Base; 406. Slide Rail; 407. Insulation Layer; 408. Graphite Heater; 409. Electrode; 410. Second Support Frame; 411. Through Hole; 412. Contraction Constraint Locking Rod Structure; 413. Ball Screw; 414. Screw Nut; 415. Rotary Wheel; 5. Water Cooling Section; 501. Water Cooling Section Shell; 503. Third Stainless Steel Corrugated Pipe; 504. Circulating Water Inlet Pipe; 505. Placement Rack; 506. Circulating Water Outlet Pipe; 507. Third Support Frame; 508. Water Cooling Layer; 6. Sintering Discharge Airtight Mechanism; 601. Second Buffer Connection Chamber; 602. Fourth Sealed Hanging Door; 603. Fifth sealed lifting door; 604, Third airtight chamber; 605, Fourth airtight chamber; 606, Sixth sealed lifting door; 607, Fifth propulsion structure; 608, Fourth propulsion structure; 609, Sixth propulsion structure; 610, Seventh propulsion structure; 7, Sintering discharge conveyor section; 8, Material unloading horizontal push section; 9, Horizontal push section; 10, Carrier box. Detailed Implementation

[0037] The present application will now be described in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit its scope. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present application, not the entire structure.

[0038] In the description of this application, unless otherwise expressly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0040] This application discloses a continuous degumming and sintering integrated furnace using a negative pressure process (hereinafter referred to as the continuous degumming and sintering integrated furnace for ease of description). The continuous degumming and sintering integrated furnace is connected to the degreasing discharge end of the catalytic degreasing continuous furnace via a transverse push section 9. Referring to Figures 1-3, the continuous degumming and sintering integrated furnace disclosed in this application includes a sintering feed airtight mechanism 1 for the passage of the carrier box 10, a degumming furnace section 2, a sintering furnace section 4, a water cooling section 5, and a sintering discharge airtight mechanism 6. The sintering feeding airtight mechanism 1 is configured to provide airtight feeding of the degreased material in the carrier box 10 (when the carrier box enters the continuous debinding sintering integrated furnace, air is blocked from entering the continuous debinding sintering integrated furnace); the debinding furnace section 2 is configured to perform high-temperature debinding on the material in the conveyed carrier box 10; the sintering furnace section 4 is configured to perform high-temperature sintering on the material in the conveyed carrier box 10; the water cooling section 5 is configured to cool the material in the conveyed carrier box 10; and the sintering discharge airtight mechanism 6 is configured to discharge the sintered material in the carrier box 10... The material is discharged in an airtight manner (when the carrier box is discharged from the continuous degumming sintering furnace, air is prevented from entering the continuous degumming sintering furnace); the continuous degumming sintering furnace is vacuumed and filled with argon gas, so that argon gas is airtightly filled from the end of the water-cooling section 5 to the beginning of the degumming furnace section 2. The sintering feeding airtight mechanism 1 and the sintering discharging airtight mechanism 6, through vacuuming and filling with argon gas, can isolate air when the carrier box 10 enters the degumming furnace section and is discharged from the water-cooling section, and ensure the maintenance of negative pressure in the continuous degumming sintering furnace.

[0041] The discharge end of the continuous degumming and sintering furnace using negative pressure technology is connected to the feed end of the catalytic degreasing continuous furnace via a transverse push section. The continuous degumming and sintering furnace using negative pressure technology and the catalytic degreasing continuous furnace are connected end-to-end by two transverse push sections, forming a closed loop. This allows the material in the carrier box to be degreased in the catalytic degreasing continuous furnace and then directly enter the continuous degumming and sintering furnace using negative pressure technology for debinding and sintering.

[0042] Understandably, in actual operation, the continuous degumming sintering furnace utilizes external vacuum and argon filling devices to create negative pressure and introduce argon gas, offering advantages such as high safety and wide applicability. The sintering feed airtight mechanism 1 and the sintering discharge airtight mechanism 6, through vacuuming and argon filling, ensure that oxygen is effectively prevented from entering the furnace when the carrier box 10 enters and exits, thus guaranteeing the efficiency and safety of the internal reaction.

[0043] In actual operation, the sintering feeding airtight mechanism 1 and the sintering discharging airtight mechanism 6 are connected to the external argon filling device and the external vacuum device. The degumming furnace section 2 is connected to the external vacuum device. In actual operation, during the feeding and discharging process, the sintering feeding airtight mechanism 1 and the sintering discharging airtight mechanism 6, in conjunction with the argon filling device and the vacuum device, achieve oxygen-isolated feeding and discharging.

[0044] Referring to Figure 4, the sintering feed airtight mechanism 1 consists of two airtight chambers with sealed lifting doors and three corresponding propulsion structures. These three propulsion structures push the tray at the bottom of the support box 10 and open the corresponding sealed lifting doors, coordinating with vacuuming and argon purging. It is understood that the dual airtight chambers combined with the three sealed lifting doors effectively prevent oxygen from entering the furnace. Before the support box 10, containing materials, enters the sintering furnace, the airtight chambers are used to isolate oxygen, ensuring the efficiency and safety of the internal reaction. The propulsion structures abut against the side of the bottom tray of the support box 10, advancing intermittently. Compared to a single furnace, this transforms the previously lengthy degreasing, degumming, sintering, and cooling processes into continuous feeding with short intervals, significantly improving efficiency and increasing production capacity.

[0045] In some embodiments, referring to FIG4, the sintering feed airtight mechanism 1 includes a first airtight chamber 101, a first sealed lifting door 102, a first propulsion structure 103, a third propulsion structure 104, a second airtight chamber 105, a second sealed lifting door 106, a third sealed lifting door 107, a first buffer connecting chamber 108, and a second propulsion structure 110; the first propulsion structure 103 is located at the tail of the transverse push section 9 and is arranged perpendicular to the transport direction of the carrier box 10; the first airtight chamber 105 is located at the front of the push head of the first propulsion structure 103, and the first sealed lifting door 102 is located at the tail of the transverse push section 9. The first airtight chamber 101 has an inlet end; a second propulsion structure 110 is disposed on the side of the first airtight chamber 101 and is arranged perpendicular to the first propulsion structure 103; a second sealing door 106 is disposed at the outlet end of the first airtight chamber 101 and is connected to the second airtight chamber 105; a third propulsion structure 104 is disposed on the side of the second airtight chamber 105 and is arranged parallel to the first propulsion structure 103; a third sealing door 107 is disposed at the outlet end of the second airtight chamber 105 and is connected to the first buffer connecting chamber 108, which is connected to the inlet of the degumming furnace section 2. Understandably, in actual operation, after the carrier box 10 is lifted by the first sealed door 102 and pushed into the first airtight chamber 101 by the first propulsion structure 103, the first propulsion structure 103 retracts and the first sealed door 102 is lowered. Then, argon gas is introduced into the first airtight chamber 101 to expel the air inside. Next, the second sealed door 106 opens, and the carrier box 10 enters the second airtight chamber 105 under the action of the second propulsion structure 110. Slightly positive pressure argon gas is then introduced into the second airtight chamber 105 to expel the remaining oxygen from the second airtight chamber 101. Argon is discharged into the first airtight chamber 101. After a period of time, when the second airtight chamber 105 is fully filled with argon, the second sealing door 106 is closed, and the second airtight chamber 105 is evacuated so that the pressure inside the second airtight chamber 105 is the same as the pressure inside the continuous degumming sintering integrated furnace. Then the third sealing door 107 is opened, and the carrier box 10 enters the degumming furnace section 2 through the first buffer connecting chamber 108 under the action of the third propulsion structure 104. This can minimize and avoid the entry of oxygen to the greatest extent, thereby fully isolating oxygen from entering the furnace and ensuring the efficiency and safety of the internal reaction.

[0046] The first sealed hanging door 102, the second sealed hanging door 106, and the third sealed hanging door 107 all adopt a structure with a cylinder at the top and a hanging door at the bottom. Airtight sealing strips are provided on the lifting door plates, ensuring airtightness within the airtight chamber when the doors are closed. The first propulsion structure 103, the second propulsion structure 110, and the third propulsion structure 104 can be pneumatic cylinders, electric cylinders, or hydraulic cylinders. Other components capable of achieving the same propulsion function and effect are also within the scope of protection of this technical solution.

[0047] The argon filling device uses a professional high-pressure hydraulic vaporization device for argon gas, including an evaporator, pressure regulator, flow meter, solenoid valve, etc.

[0048] In some embodiments, as shown in FIG12, the first airtight chamber 101 and the second airtight chamber 105 are provided with guide rails 111 for the carrier box 10 to move forward. The first propulsion structure 103, the second propulsion structure 110, and the third propulsion structure 104 all advance by pushing the side of the tray at the bottom of the carrier box 10 forward. It can be understood that the guide rails 111 are configured to restrict the movement direction of the carrier box 10 and support the carrier box 10, so as to avoid the carrier box 10 from tilting during actual operation. The first propulsion structure 103, the second propulsion structure 110, and the third propulsion structure 104 all advance by pushing the side of the tray at the bottom of the carrier box 10 forward. In actual operation, they can stably drive the carrier box 10 to move and advance it forward at intervals, realizing continuous feeding with very short intervals, which greatly improves efficiency and increases production capacity.

[0049] In some embodiments, the first airtight chamber 101, the second airtight chamber 105, and the first buffer connecting chamber 108 are each provided with a transparent observation window 112, and a first stainless steel corrugated pipe 109 is provided in the channel between the first buffer connecting chamber 108 and the inlet of the degumming furnace section 2. It is understood that providing transparent observation windows 112 in the first airtight chamber 101, the second airtight chamber 105, and the first buffer connecting chamber 108 allows users to easily observe the process, enabling staff to promptly observe the feeding status and detect any abnormalities in the feeding process.

[0050] In some embodiments, the first airtight chamber 101 and the second airtight chamber 105 are provided with a vacuuming pipe connected to a vacuuming device and an argon filling pipe connected to an argon filling device. It is understood that by using the vacuuming pipe and the argon filling pipe to perform the argon filling operation of the first airtight chamber 101 and the vacuuming and argon filling operation of the second airtight chamber 105, it is ensured that during the feeding process, the sintering feed airtight mechanism 1 can stably cooperate with the operation of the argon filling device and the vacuuming device to achieve oxygen-isolated feeding.

[0051] Referring to Figure 3, a wax collecting device 3 is installed on the side of the degumming furnace section 2. The wax collecting device 3 is designed to condense and collect the wax oil formed by the sublimation and degumming of the material in the carrier box 10. The wax collecting device 3 can be composed of a main pipeline connected to the degumming furnace section 2, a vacuum pump set 302 connected to two branch pipelines at the end of the main pipeline, and a wax collecting box 301. A condenser is provided between the top of the wax collecting box 301 and the vacuum pump set 302. It can be understood that the condenser can condense the wax oil in the high-temperature steam state into a liquid wax oil state for recovery. With the structure of two sets of vacuum pump sets 302 and wax collecting box 301, when one wax collecting device is damaged for repair or wax oil collection, one wax collecting device can still operate normally, continuously providing a negative pressure environment and continuously collecting wax.

[0052] In some embodiments, referring to FIG5, the degumming furnace section 2 is provided with an electric heating wire 203 for heating the inner furnace wall of the degumming furnace section 2. The electric heating wire 203 is installed between the inner furnace wall and the outer furnace 202 of the degumming furnace. A first heat insulation layer 201 is provided between the electric heating wire 203 and the outer furnace 202 of the degumming furnace. The first heat insulation layer 201 is made of lightweight insulating brick and is installed between the inner furnace wall and the outer furnace 202 of the degumming furnace through a first support frame 204. The degumming furnace section 2 is composed of a multi-zone structure from the beginning to the end, and the heating temperature of the electric heating wire 203 gradually increases in each zone. It can be understood that the added first heat insulation layer 201 can reduce the heat diffusion from the inside of the degumming furnace section 2 to the outside, which is beneficial to reducing the heat loss of the degumming furnace section 2, thereby reducing the energy consumption of the continuous degumming sintering integrated furnace. In this embodiment, the degumming furnace section 2 is divided into six sections, and the heating wire temperature gradually increases from room temperature at the beginning to about 800°C at the end, which greatly reduces energy consumption while meeting the degumming reaction temperature.

[0053] Referring to Figures 6-8, the sintering furnace section 4 includes a graphite heater 408 for heating the inner furnace wall, an insulation layer 407 disposed outside the graphite heater 408, a second insulation layer 402 disposed outside the insulation layer 407, and a sintering furnace shell 401 disposed outside the second insulation layer 402. As shown in Figure 13, the sintering furnace shell 401 has through holes 411 for pipelines connecting electrodes 409 on the graphite heater 408 to pass through; the graphite heater 408 is disposed between the inner furnace wall supported by the second support frame 410 and the sintering furnace shell 401. It can be understood that the second insulation layer 402 is made of graphite felt or soft felt. The second insulation layer 402 can ensure the heat insulation effect, reduce the heat diffusion from the inside of the sintering furnace section 4 to the outside, and help reduce the heat loss of the sintering furnace section 4, thereby reducing the energy consumption of the continuous degumming sintering integrated furnace.

[0054] In some embodiments, the sintering furnace section 4 has a multi-segment structure, with the temperature of the multiple graphite heaters 408 within the multi-segment sintering furnace section 4 increasing sequentially from the starting end to the end. In this embodiment, the sintering furnace section 4 has a three-segment structure, with the temperature of the multiple graphite heaters 408 rising from 800°C at the starting end to approximately 1400°C at the end, thus significantly reducing energy consumption while precisely meeting the temperature and time requirements for sintering at the end.

[0055] In some embodiments, adjacent sintering furnace sections 4 are connected by a flange with a second stainless steel bellows 403, which is provided with a shrinkage constraint locking rod structure 412. It is understood that the shrinkage constraint locking rod structure 412 is a double-ended counter-rotating screw and a threaded connection seat; forward and reverse rotation can cause the second stainless steel bellows 403 to expand or retract. In actual operation, when maintenance is required inside the sintering furnace shell 401, the shrinkage constraint locking rod structure 412 is operated to retract the second stainless steel bellows 403, and then the corresponding sintering furnace section 4 can be moved for maintenance, making the operation very convenient.

[0056] The bottom of each sintering furnace section 4 is slidably fitted onto the base 405 via a bracket 404. The bracket 404 and the slide rail 406 on the base 405 are slidably fitted via a slider, as shown in Figure 14. A screw nut 414 that engages with a ball screw 413 is also installed at the bottom of the bracket 404. A roller 415 is located at the end of the ball screw 413. Rotating the roller 415 causes the sintering furnace section 4 to move laterally along the slide rail 406. Understandably, in actual operation, when the second stainless steel corrugated pipe 403 retracts, the operator only needs to rotate the roller 415. During the rotation of the ball screw 413, the screw nut 414 will move along the axial direction of the ball screw 413. This movement of the screw nut 414 will drive the bracket 404 and the sintering furnace section 4 to move horizontally, making operation very convenient. The slide rail 406 and slider restrict the movement direction of the bracket 404 and the sintering furnace section 4, preventing misalignment and jamming during maintenance.

[0057] Referring to Figures 9 and 10, the water-cooled section 5 has a multi-segment structure. The water-cooled section 5 is connected to the sintering discharge airtight mechanism 6 through the third stainless steel corrugated pipe 503. Each water-cooled section 5 has a placement rack 505 at the bottom. The water-cooled section 5 has a water-cooled layer 508 that wraps around the inner furnace wall. The water-cooled layer 508 has a circulating water inlet pipe 504 and a circulating water outlet pipe 506 connected to it. The water-cooled layer 508 is fixed between the outer shell 501 of the water-cooled section and the inner furnace wall through the third support frame 507. It is understandable that the water-cooling section 5 is connected to the sintering discharge airtight mechanism 6 via the third stainless steel corrugated pipe 503. The third stainless steel corrugated pipe 503 is equipped with a shrinkage constraint locking rod structure 412. In actual operation, the shrinkage constraint locking rod structure 412 can be operated to retract and expand the third stainless steel corrugated pipe 503, thereby realizing the assembly and disassembly of the water-cooling section 5 and the sintering discharge airtight mechanism 6. This allows for easy disconnection of the water-cooling section 5 from the sintering discharge airtight mechanism 6 during maintenance, facilitating operation. In this embodiment, the water-cooling section 5 adopts a two-section structure. The water temperature is reduced from approximately 1000°C at the beginning of the water-cooling section 5 to approximately 100°C at the end under the action of the water-cooling layer 508, i.e., the water-cooling interlayer, thus meeting the discharge temperature requirements.

[0058] Referring to Figure 11, the sintering discharge airtight mechanism 6 consists of two airtight chambers with sealed lifting doors and three corresponding propulsion structures. The double airtight chambers combined with the three sealed lifting doors effectively prevent oxygen from entering the furnace. Before the material-containing carrier box 10 leaves the sintering furnace, the airtight chambers are used to isolate oxygen, ensuring the efficiency and safety of the internal reaction. The propulsion structures abut against the side of the bottom support plate of the carrier box 10, advancing forward intermittently. Compared to a single furnace, this transforms the previously lengthy degreasing, degumming, sintering, and cooling processes into continuous discharge with short intervals, significantly improving efficiency and increasing production capacity.

[0059] In some embodiments, the sintering discharge airtight mechanism 6 includes a second buffer connecting chamber 601, a fourth sealing lifting door 602, a fifth sealing lifting door 603, a third airtight chamber 604, a fourth airtight chamber 605, a sixth sealing lifting door 606, a fifth propulsion structure 607, a fourth propulsion structure 608, a sixth propulsion structure 609, and a seventh propulsion structure 610; wherein, the fourth propulsion structure 608 is located at the tail of the water-cooled section 5 and is arranged perpendicular to the transport direction of the carrier box 10; the second buffer connecting chamber 601 is located in front of the lifting head of the fourth propulsion structure 608; the third airtight chamber 604... 604 is connected to the second buffer connection chamber 601 through the fourth sealing door 602; the fifth propulsion structure 607 is located on the side of the third airtight chamber 604 and is arranged perpendicular to the fourth propulsion structure 608; the fourth airtight chamber 605 is connected to the outlet end of the third airtight chamber 604 through the fifth sealing door 603; the sixth propulsion structure 609 is located on one side of the fourth airtight chamber 605 and is arranged perpendicular to the fifth propulsion structure 607; the sixth sealing door 606 is located at the outlet end of the fourth airtight chamber 605; the seventh propulsion structure 610 is arranged perpendicular to the sixth propulsion structure 609. Understandably, during actual operation, the third airtight chamber 604 and the fourth airtight chamber 605 are continuously filled with slightly positive pressure argon to reduce and prevent oxygen from entering the continuous degumming sintering furnace. When the carrier box 10 enters the second buffer connecting chamber 601 from the water-cooled section 5, the argon filling of the third airtight chamber 604 is stopped and a vacuum is drawn to make the pressure in the third airtight chamber 604 equal to that in the continuous degumming sintering furnace. After the pressure is equal, the fourth sealed lifting door 602 opens, and the carrier box 10 enters the third airtight chamber 604 from the second buffer connecting chamber 601 under the action of the fourth propulsion structure 608. After the carrier box 10 enters the third airtight chamber 604, the fourth sealed lifting door 602... The third airtight chamber 604 is closed and filled with argon to make the pressure in the third airtight chamber 604 the same as that in the fourth airtight chamber 605. The fifth sealing door 603 is opened, and the carrier box 10 enters the fourth airtight chamber 605 under the pushing action of the fifth propulsion structure 607. After the carrier box 10 enters, the fifth sealing door 603 is closed, and the sixth sealing door 606 is opened. After the carrier box 10 leaves the fourth airtight chamber 605 under the action of the sixth propulsion structure 609, the sixth sealing door 606 is closed. Then, under the propulsion action of the seventh propulsion structure 610, it enters the sintering discharge conveying section 7 and is transported by the sintering discharge conveying section 7 to the end of the unloading horizontal push section 8 for unloading.

[0060] The fourth sealing door 602, the fifth sealing door 603, and the sixth sealing door 606 all adopt a structure with a cylinder at the top and a door at the bottom. The lifting door plates of the doors are equipped with airtight sealing strips to maintain airtightness inside the airtight chamber when the doors are closed. The fourth propulsion structure 608, the fifth propulsion structure 607, and the seventh propulsion structure 610 can use cylinders, electric cylinders, or hydraulic cylinders. Other components capable of achieving the same propulsion function and effect are also within the scope of protection of this technical solution.

[0061] The continuous degumming and sintering integrated furnace of this application embodiment:

[0062] First: The furnace is evacuated by a vacuum pump and argon is introduced into the furnace by an argon filling device. This has the advantages of continuous furnace with low energy loss and high product output.

[0063] Second: Both the sintering feeding airtight mechanism 1 and the sintering discharging airtight mechanism 6 adopt a pushing structure that abuts against the side of the bottom support plate of the bearing box 10 and pushes forward at intervals. Compared with a single furnace, this transforms the degreasing, degumming, sintering and cooling processes that originally required a long time into continuous feeding and discharging with very short intervals, which greatly improves efficiency and increases production capacity.

[0064] Third, both the sintering feeding airtight mechanism 1 and the sintering discharging airtight mechanism 6 adopt a double airtight chamber and a triple sealing door structure, which can fully isolate oxygen from entering the furnace. Before the material-containing carrier box 10 enters the sintering furnace, an airtight chamber is needed to isolate oxygen, which fully ensures the efficiency and safety of the internal reaction.

[0065] Fourth, the structure of two sets of vacuum pump sets 302 and wax collection box 301 can ensure that when one wax collection device is damaged for repair or wax collection, another wax collection device can still work normally, providing a continuous negative pressure environment and continuously collecting wax.

[0066] Fifth, the degumming furnace section 2 has a multi-zone structure, and the temperature of the heating wires in the multi-zone structure gradually increases from the beginning to the end of the degumming furnace section 2, which greatly reduces energy consumption while meeting the degumming reaction temperature.

[0067] Sixth: The sintering furnace section 4 is a multi-section structure, and the two adjacent sintering furnace sections 4 are connected by a flange with a second stainless steel corrugated pipe 403. The bottom of each sintering furnace section 4 is equipped with a push-out mechanism that can move laterally. When the sintering furnace section 4 is damaged and needs to be repaired, the furnace body can be moved horizontally by shrinking the two flanges to carry out efficient repairs.

[0068] Seventh: The sintering furnace section 4 adopts a multi-section structure with gradually increasing temperature. The temperature required for sintering is just met at the end of the sintering furnace section 4, which greatly reduces energy consumption while meeting the sintering reaction temperature.

[0069] Eighth: Water cooling section 5 is connected using a third type of stainless steel corrugated pipe 503, which facilitates repair in case of internal damage and greatly improves production efficiency.

[0070] In the description of this specification, the references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A continuous degumming and sintering integrated furnace employing a negative pressure process, comprising: The sintering feeding airtight mechanism (1), degumming furnace section (2), sintering furnace section (4), water cooling section (5), and sintering discharging airtight mechanism (6) are provided for the passage of the carrier box (10); wherein, the sintering feeding airtight mechanism (1) is configured to feed the degreased material in the carrier box (10) in an airtight manner; the degumming furnace section (2) is configured to degumme the material in the carrier box (10) at high temperature; the sintering furnace section (4) is configured to sinter the material in the carrier box (10) at high temperature; the water cooling section (5) is configured to cool the material in the carrier box (10); and the sintering discharging airtight mechanism (6) is configured to discharge the sintered material in the carrier box (10) in an airtight manner. The continuous degumming sintering integrated furnace using negative pressure process is subjected to vacuuming and argon filling, so that argon gas is airtightly filled from the end of the water-cooling section (5) to the beginning of the degumming furnace section (2). The sintering feeding airtight mechanism (1) and the sintering discharging airtight mechanism (6) are vacuumed and filled with argon to prevent air from entering the continuous degumming sintering integrated furnace when the carrier box (10) enters the degumming furnace section (2) and exits from the water-cooling section (5), and to ensure that the negative pressure in the continuous degumming sintering integrated furnace remains stable. The feed end of the continuous degumming and sintering integrated furnace using negative pressure process is connected to the degreasing discharge end of the catalytic degreasing continuous furnace via a transverse push section (9).

2. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 1, wherein, The sintering feeding airtight mechanism (1) consists of two airtight chambers with three sealed hanging doors and a corresponding propulsion structure. The propulsion structure pushes the tray at the bottom of the carrier box (10) and opens the corresponding sealed hanging door. In conjunction with the vacuuming and argon filling actions, the carrier box (10) blocks air from entering the continuous degumming sintering integrated furnace.

3. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 2, wherein, The sintering feed airtight mechanism (1) includes a first airtight chamber (101), a first sealed lifting door (102), a first propulsion structure (103), a second propulsion structure (110), a second airtight chamber (105), a second sealed lifting door (106), a third sealed lifting door (107), a first buffer connection chamber (108), and a third propulsion structure (104); the first propulsion structure (103) is located at the tail of the transverse push section (9) and is arranged perpendicular to the transport direction of the carrier box (10); the first airtight chamber (101) is located in front of the lifting head of the first propulsion structure (103), and the first sealed lifting door (102) is located at the inlet of the first airtight chamber (101). The second propulsion structure (110) is located on the side of the first airtight chamber (101) and is arranged perpendicular to the first propulsion structure (103); the second sealing door (106) is located at the outlet end of the first airtight chamber (101) and is connected to the second airtight chamber (105); the third propulsion structure (104) is located on the side of the second airtight chamber (105) and is arranged parallel to the first propulsion structure (103); the third sealing door (107) is located at the outlet end of the second airtight chamber (105) and is connected to the first buffer connection chamber (108), and the first buffer connection chamber (108) is connected to the inlet of the degumming furnace section (2).

4. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 3, wherein, The first airtight chamber (101) and the second airtight chamber (105) are provided with guide rails (111) for the carrier box (10) to move forward. The first propulsion structure (103), the second propulsion structure (110) and the third propulsion structure (104) all move forward by pushing the side of the tray at the bottom of the carrier box (10).

5. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 3, wherein, The first airtight chamber (101), the second airtight chamber (105) and the first buffer connection chamber (108) are all provided with transparent observation windows (112), and the first stainless steel corrugated pipe (109) is provided in the channel between the first buffer connection chamber (108) and the inlet of the degumming furnace section (2).

6. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 1, wherein, The degumming furnace section (2) is provided with a wax collection device (3) on its side. The wax collection device (3) is configured to collect the wax oil formed by the degumming and sublimation of the material in the carrier box (10) and then condensation.

7. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 6, wherein, The wax collection device (3) consists of a main pipeline connected to the degumming furnace section (2), a vacuum pump group (302) connected to two branch pipelines at the end of the main pipeline, and a wax collection box (301). A condenser is provided between the top of the wax collection box (301) and the vacuum pump group (302).

8. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 1, wherein, The degumming furnace section (2) is composed of a multi-zone structure from the beginning to the end. Each zone of the degumming furnace section (2) is provided with an electric heating wire (203) for heating the inner furnace wall of the degumming furnace section (2). The electric heating wire (203) is installed between the inner furnace wall and the outer furnace (202) of the degumming furnace. A first heat insulation layer (201) supported by a first support frame (204) is provided between the electric heating wire (203) and the outer furnace (202) of the degumming furnace. The heating temperature of the electric heating wire (203) in the multi-zone structure gradually increases.

9. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 1, wherein, The sintering furnace section (4) includes a graphite heater (408) for heating the inner furnace wall of the sintering furnace section (4), a heat insulation layer (407) disposed outside the graphite heater (408), a second heat insulation layer (402) disposed outside the heat insulation layer (407), and a sintering furnace shell (401) disposed outside the second heat insulation layer (402); wherein: The outer shell (401) of the sintering furnace is provided with a through hole (411) through which the pipeline connecting the electrode (409) on the graphite heater (408) passes; The graphite heater (408) is located between the inner furnace wall and the sintering furnace outer shell (401) supported by the second support frame (410); The sintering furnace section (4) has a multi-segment structure, and the temperature of the multiple graphite heaters (408) in the multiple sintering furnace sections (4) increases sequentially from the starting end to the end.

10. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 9, wherein, The two adjacent sintering furnace sections (4) are connected by a flange with a second stainless steel bellows (403), and the second stainless steel bellows (403) is provided with a shrinkage constraint locking rod structure (412). The bottom of each sintering furnace section (4) is slidably fitted onto the base (405) via a bracket (404). The bracket (404) and the slide rail (406) on the base (405) are slidably fitted together via a slider. The bottom of the bracket (404) is also equipped with a screw nut (414) that cooperates with the ball screw (413). The end of the ball screw (413) is provided with a rotating wheel (415). By rotating the rotating wheel (415), the sintering furnace section (4) moves laterally along the slide rail (406).

11. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 9, wherein, The water-cooling section (5) has a multi-segment structure, and the water-cooling section (5) is connected to the sintering discharge airtight mechanism (6) through a third stainless steel corrugated pipe (503). Each water-cooled section (5) is provided with a placement rack (505) at the bottom. The water-cooled section (5) is provided with a water-cooled layer (508) that wraps the inner furnace wall of the water-cooled section (5). A circulating water inlet pipe (504) and a circulating water outlet pipe (506) are connected to the water-cooled layer (508). The water-cooled layer (508) is fixed between the outer shell (501) of the water-cooled section and the inner furnace wall by a third support frame (507).

12. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 1, wherein, The sintering discharge airtight mechanism (6) consists of two airtight chambers with three sealed hanging doors and a corresponding propulsion structure. The propulsion structure pushes the tray at the bottom of the carrier box (10) and opens the corresponding sealed hanging door, and cooperates with the vacuuming and argon filling actions to achieve airtight discharge.

13. The continuous degumming and sintering integrated furnace using negative pressure process according to claim 12, wherein, The sintering discharge airtight mechanism (6) includes a second buffer connection chamber (601), a fourth sealed lifting door (602), a fifth sealed lifting door (603), a third airtight chamber (604), a fourth airtight chamber (605), a sixth sealed lifting door (606), a fourth propulsion structure (608), a fifth propulsion structure (607), a sixth propulsion structure (609), and a seventh propulsion structure (610); The fourth propulsion structure (608) is located at the tail of the water-cooled section (5) and is arranged perpendicular to the transport direction of the carrier box (10); the second buffer connection chamber (601) is located in front of the lifting head of the fourth propulsion structure (608); the third airtight chamber (604) is connected to the second buffer connection chamber (601) through the fourth sealing door (602); the fifth propulsion structure (607) is located on the side of the third airtight chamber (604) and is arranged perpendicular to the fourth propulsion structure (608); the fourth airtight chamber (605) is connected to the second buffer connection chamber (601) through the fourth sealing door (602). The fifth sealing door (603) is connected to the outlet end of the third airtight chamber (604); the sixth propulsion structure (609) is located on one side of the fourth airtight chamber (605) and is arranged perpendicularly to the fifth propulsion structure (607); the sixth sealing door (606) is located at the outlet end of the fourth airtight chamber (605); the seventh propulsion structure (610) is located at the outlet end of the fourth airtight chamber (605) and is configured to propel the side of the bottom tray of the carrier box (10), and the seventh propulsion structure (610) is arranged perpendicularly to the sixth propulsion structure (609).

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