Continuous preheating structure of iron powder sintering furnace

Abstract

The application belongs to the technical field of powder metallurgy equipment, and discloses a continuous preheating structure of an iron powder sintering furnace, which comprises a preheating cover, a conveying mechanism is fixedly installed in the preheating cover, a feeding cylinder is arranged at the top of the conveying mechanism, a backflow pipe in communication with the conveying mechanism is arranged at the bottom of the preheating cover, and a multistage dispersion mechanism is rotatably arranged in the preheating cover. All preheating links such as spiral conveying, multistage dispersion, heating and backflow are integrated in a closed preheating cover, a gas circulation mechanism is arranged, the iron powder is transferred from the conveying midway to the preheating cover for sufficient preheating by cooperation of spiral conveying, and the preheated iron powder is backflowed to the conveying mechanism, so that the iron powder is effectively prevented from contacting with external air during the preheating process, the whole preheating process is ensured to be carried out in pure protective gas, secondary oxidation of the iron powder is avoided, and high activity and high purity of the powder entering the sintering furnace are ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of powder metallurgy equipment, and particularly relates to a continuous preheating structure of an iron powder sintering furnace. BACKGROUND

[0002] Powder metallurgy is an advanced manufacturing technology for manufacturing metal materials, composite materials and various types of products by taking metal powder as raw material and through forming and sintering processes. Among them, sintering is a core link for determining the density, mechanical properties and dimensional accuracy of the final product. Before entering the high-temperature sintering furnace, the powder green body or loose metal powder formed by pressing is fully and uniformly preheated, which is a crucial step in the entire sintering process.

[0003] However, the existing iron powder preheating technology and equipment still have a series of technical problems to be solved in the pursuit of high-efficiency, continuous and high-quality modern production mode:

[0004] First, continuous production and effective gas protection are difficult to balance. Iron powder has high chemical activity at preheating temperature (usually several hundred degrees Celsius), and is easily oxidized with oxygen in the air, which will seriously affect the subsequent sintering effect. Therefore, the preheating process must be carried out in a protective gas (such as nitrogen, hydrogen or decomposed ammonia). The batch equipment such as box furnace can achieve good gas protection, but its production efficiency is low and cannot meet the needs of large-scale continuous production. While the continuous preheating equipment such as mesh belt furnace or push rod furnace can realize continuous production, but it is difficult to achieve complete gas sealing at the feeding and discharging end, and air is easily rolled in, which leads to the oxidation of iron powder during preheating and affects the preheating effect.

[0005] Second, the powder heat transfer efficiency is low, and the preheating is uneven. Metal powder is a typical granular assembly, and its heat conductivity is poor in the stacking state. In the static or simple conveying preheating mode, it is difficult for heat to quickly and uniformly transfer to the inside of the powder pile, which often leads to overheating of the outer powder while the internal powder temperature still does not reach the set value, directly affecting the uniformity of the sintering process, leading to inconsistent organization and performance of the final product, and poor comprehensive use effect. SUMMARY

[0006] The purpose of the present application is to provide a continuous preheating structure of an iron powder sintering furnace to solve the problems raised in the background art.

[0007] In order to achieve the above object, the present application provides the following technical scheme: a continuous preheating structure of an iron powder sintering furnace, comprising a preheating cover, a conveying mechanism fixedly installed inside the preheating cover, an inlet cylinder provided at the top of the conveying mechanism, a backflow pipe communicated with the conveying mechanism and provided at the bottom of the preheating cover, a plurality of multistage dispersion mechanisms rotatably provided in the preheating cover, a reciprocating dispersion assembly provided outside the conveying mechanism, the reciprocating dispersion assembly located inside the multistage dispersion mechanisms, heating pipes circumferentially provided on the multistage dispersion mechanisms, and a protective gas filled in the preheating cover.

[0008] The conveying mechanism is used for conveying the iron powder conveyed inside to the preheating cover, the reciprocating dispersion assembly is used for dispersing the iron powder input into the preheating cover on the multistage dispersion mechanisms, and the multistage dispersion mechanisms are used for dispersing and guiding the iron powder to flow back to the conveying mechanism through the backflow pipe.

[0009] Preferably, the conveying mechanism comprises a conveying pipe, a conveying shaft and helical blades, the conveying shaft is rotatably sleeved in the conveying pipe, the helical blades are fixedly installed on the conveying shaft, the conveying pipe is fixedly communicated in the inside of the inlet cylinder, the inside of the inlet cylinder is provided with a power mechanism, and the output shaft of the power mechanism is fixedly connected with the conveying shaft.

[0010] Preferably, the pipe wall of the conveying pipe is further provided with dispersion ports and backflow ports, the backflow ports are communicated with the backflow pipe, and the dispersion ports are distributed on the outside of the conveying pipe from top to bottom.

[0011] Preferably, the multistage dispersion mechanisms comprise dispersion inner covers, dispersion outer covers and intermediate rods, the dispersion outer covers are fixedly installed outside the dispersion inner covers, the top of the dispersion outer cover is a circular table surface, the intermediate rods are fixedly installed inside each dispersion outer cover, the number and position of the dispersion inner covers are matched with the number and position of the dispersion ports, and the heating pipes are fixedly circumfered at the bottom of the dispersion outer cover.

[0012] Preferably, the reciprocating dispersion assembly comprises pushing rings, connecting rods, connecting rings and springs, the pushing rings are movably sleeved outside the conveying pipe and movably sleeved inside the dispersion inner covers, the connecting rods are fixedly passed through the pushing rings in sequence, the pushing rings are one-to-one corresponding to the dispersion inner covers, the connecting ring is located below the preheating cover, the bottom end of the connecting rod is movably passed through the preheating cover and fixedly connected with the connecting ring, one end of the spring is fixed on the connecting ring, the other end of the spring is fixed on the bottom of the preheating cover, and the pushing rings and the dispersion ports are staggered distributed from top to bottom.

[0013] Preferably, the backflow pipe is provided with a reciprocating driving part, the reciprocating driving part comprises a driving motor and a cam, the cam is fixedly installed on the output shaft of the driving motor, the driving motor is fixed between the backflow pipes through an external support, and the cam is located at the bottom of the connecting ring and abuts against the connecting ring.

[0014] Preferably, the bottom of the connecting ring is fixedly connected with an impact column, the impact column corresponds to the return pipe one by one, and the impact column reciprocatingly impacts the return pipe following the reciprocating dispersion assembly.

[0015] Preferably, the inside of the preheating cover is fixedly connected with a guide cover, the guide cover is located below the dispersion cover, the bottom of the preheating cover is provided with a through port communicated with the return pipe, and the guide cover guides the preheated and dispersed powder to the through port.

[0016] Preferably, the inside of the preheating cover is rotatably provided with a rotating support part, the rotating support part comprises a mounting ring, a top ring, a clamping ring, a rotating motor, a gear and an internal gear, the top of the preheating cover inner cavity is provided with an assembly ring groove, the clamping ring is fixed on the outside of the top ring, the top ring is fixed on the top of the mounting ring, the top ring and the clamping ring are rotatably sleeved in the assembly ring groove, the mounting ring is fixed on the top of the multi-stage dispersion mechanism, the internal gear is fixedly installed on the inner wall of the mounting ring, the rotating motor is fixed on the top of the preheating cover, the gear is located on the inside of the internal gear and is in meshing connection with the internal gear, and the gear is fixedly installed on the output shaft of the rotating motor.

[0017] Preferably, the outer peripheral wall of the mounting ring is fixedly connected with a cleaning rod, the cleaning rod is distributed in the preheating cover and is movably attached to the inner wall of the preheating cover.

[0018] Preferably, the inside of the preheating cover is provided with a gas circulation mechanism, the gas circulation mechanism comprises a suction end, an extraction end, filter cloth one, filter cloth two and a scraping piece, the extraction end is communicated and arranged at the bottom of the preheating cover, the suction end is communicated and arranged at the top of the preheating cover, the filter cloth one is fixedly connected at the bottom of the suction end, the top of the extraction end faces the space surrounded by the guide cover, the filter cloth two is symmetrically distributed on the outer side of the guide cover, the scraping piece is fixedly connected at the bottom of the lowermost dispersion cover, the scraping piece is in rotational contact with the outer side of the guide cover, and the gas circulation mechanism further comprises a circulating pump, the extraction end is communicated with the suction inlet of the circulating pump, the gas outlet of the circulating pump is communicated with the return end of the external gas source, and the suction end is communicated with the leading end of the external gas source.

[0019] The beneficial effects of the present application are as follows:

[0020] (1) the present application is by the spiral conveying, multistage dispersion, heating and reflux all preheating link is integrated in a closed preheating cover, and sets up gas circulation mechanism, utilizes the cooperation of spiral conveying, iron powder is transferred from the midway to preheating cover and is fully preheated, and the iron powder is backflowed to the conveying mechanism after preheating, effectively prevent the iron powder from contacting with the outside air in the preheating process, ensure that the preheating is carried out in pure protective gas, avoid the secondary oxidation of iron powder, ensure the high activity and high purity of the powder into the sintering furnace;

[0021] (2) the present application is by the composite motion of reciprocating dispersion assembly and rotating multistage dispersion mechanism, the powder is uniformly scattered from the center to the periphery by reciprocating motion, and the powder forms a thin and constantly updated material curtain on the heating cone surface by rotating motion, so that each powder particle has equal opportunity to fully exchange heat with the heat source, effectively solve the problem of large temperature difference between inside and outside and uneven preheating caused by powder accumulation in traditional static or simple conveying mode, realize the above-mentioned gas protection preheating, further improve the preheating uniformity of continuous preheating, thereby significantly shorten the preheating time and improve the energy utilization efficiency;

[0022] (3) the present application is by the driving source of reciprocating dispersion assembly, and the periodic vibration backflow pipe is realized by the added impact column, effectively prevent the powder that may be bonded after preheating from being blocked at the discharge port, ensure the smooth circulation, and utilize the rotation of multistage dispersion mechanism to drive the cleaning rod to continuously sweep the inner wall of the preheating cover, realize online and dead angle free self-cleaning, two integrated treatments greatly improve the operation reliability of the equipment, reduce the downtime maintenance caused by blocking and powder accumulation, and reduce the manual intervention and operating cost. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 it is the structural schematic diagram of the present application;

[0024] Figure 2 it is the sectional view of the present application;

[0025] Figure 3 it is the connection schematic diagram of the conveying mechanism and the feeding cylinder of the present application;

[0026] Figure 4 it is the sectional view of the conveying mechanism of the present application;

[0027] Figure 5 it is the sectional view of the preheating cover of the present application;

[0028] Figure 6 it is the sectional view of the multistage dispersion mechanism and the rotating support part of the present application;

[0029] Figure 7 it is the schematic diagram of the reciprocating dispersion assembly and the reciprocating drive part of the present application;

[0030] Figure 8 Schematic diagram of the rotating support part of the present application;

[0031] Figure 9 Schematic diagram of the gas backflow mechanism in Embodiment 2 of the present application;

[0032] Figure 10 Schematic diagram of the guide cover in Embodiment 2 of the present application.

[0033] In the figure: 1, preheating cover; 2, conveying mechanism; 201, conveying pipe; 202, conveying shaft; 203, spiral blade; 3, feeding cylinder; 4, backflow pipe; 5, multi-stage dispersion mechanism; 501, dispersion inner cover; 502, dispersion outer cover; 503, intermediate rod; 6, reciprocating dispersion assembly; 601, pushing collar; 602, connecting rod; 603, connecting ring; 604, spring one; 7, guide cover; 8, reciprocating driving part; 801, driving motor; 802, cam; 9, rotating support part; 901, mounting ring; 902, top ring; 903, snap ring; 904, rotating motor; 905, gear; 906, inner gear; 10, dispersion port; 11, backflow port; 12, through port; 13, assembly ring groove; 14, cleaning rod; 15, heating pipe; 16, impact column; 17, suction end; 18, extraction end; 19, filter cloth one; 20, filter cloth two; 21, scraping piece. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0035] As Figures 1 to 10 shown, the embodiment of the present application provides a continuous preheating structure of an iron powder sintering furnace, which comprises a preheating cover 1, a conveying mechanism 2 fixedly installed inside the preheating cover 1, a feeding cylinder 3 arranged at the top of the conveying mechanism 2, a backflow pipe 4 arranged at the bottom of the preheating cover 1 and communicating with the conveying mechanism 2, a multi-stage dispersion mechanism 5 rotatably arranged in the preheating cover 1, a reciprocating dispersion assembly 6 arranged outside the conveying mechanism 2, the reciprocating dispersion assembly 6 being located inside the multi-stage dispersion mechanism 5, heating pipes 15 arranged in a surrounding manner on the multi-stage dispersion mechanism 5, and protective gas filled in the preheating cover 1. The conveying mechanism 2 is used to convey the iron powder inside to the preheating cover 1. The reciprocating dispersion assembly 6 is used to disperse the iron powder input into the preheating cover 1 on the multi-stage dispersion mechanism 5. The multi-stage dispersion mechanism 5 is used to disperse and guide the iron powder to backflow to the conveying mechanism 2 through the backflow pipe 4.

[0036] The conveying mechanism 2 comprises a conveying pipe 201, a conveying shaft 202 and a spiral blade 203, the conveying shaft 202 is rotatably sleeved in the conveying pipe 201, the spiral blade 203 is fixedly installed on the conveying shaft 202, the conveying pipe 201 is fixedly connected to the inside of the feeding cylinder 3, the inside of the feeding cylinder 3 is provided with a power mechanism, and the output shaft of the power mechanism is fixedly connected with the conveying shaft 202.

[0037] The conveying mechanism 2 drives the spiral blade 203 to rotate through the conveying shaft 202, realizes spiral conveying in the conveying pipe 201, cooperates with the feeding cylinder 3 to realize downward guiding of the iron powder, and the power mechanism realizes rotation control of the conveying shaft 202 through the built-in motor, and cooperates with the built-in stirring plate to further stir the inside of the feeding cylinder 3.

[0038] The pipe wall of the conveying pipe 201 is further provided with a dispersion port 10 and a backflow port 11, the backflow port 11 is communicated with the backflow pipe 4, the dispersion port 10 is distributed on the outside of the conveying pipe 201 from top to bottom, the multi-stage dispersion mechanism 5 comprises a dispersion inner cover 501, a dispersion outer cover 502 and an intermediate rod 503, the dispersion outer cover 502 is fixedly installed outside the dispersion inner cover 501, the top of the dispersion outer cover 502 is a circular table, the intermediate rod 503 is fixedly installed inside each dispersion outer cover 502, the number and position of the dispersion inner cover 501 are matched with the number and position of the dispersion port 10, and the heating pipe 15 is fixedly surrounded at the bottom of the dispersion outer cover 502.

[0039] The reciprocating dispersion assembly 6 comprises a pushing sleeve ring 601, a connecting rod 602, a connecting ring 603 and a spring 604, the pushing sleeve ring 601 is movably sleeved on the outside of the conveying pipe 201 and movably sleeved in the dispersion inner cover 501, the connecting rod 602 is fixedly penetrated through each pushing sleeve ring 601 in sequence, the pushing sleeve ring 601 corresponds to the dispersion inner cover 501 one by one, the connecting ring 603 is located below the preheating cover 1, the bottom end of the connecting rod 602 is movably penetrated through the preheating cover 1 and is fixedly connected with the connecting ring 603, one end of the spring 604 is fixed on the connecting ring 603, and the other end of the spring 604 is fixed on the bottom of the preheating cover 1, and the pushing sleeve ring 601 is staggered distributed above and below the dispersion port 10.

[0040] The backflow pipe 4 is provided with a reciprocating driving part 8, the reciprocating driving part 8 comprises a driving motor 801 and a cam 802, the cam 802 is fixedly installed on the output shaft of the driving motor 801, the driving motor 801 is fixed between the backflow pipes 4 through an external support, the cam 802 is located at the bottom of the connecting ring 603 and abuts against the connecting ring 603. The inside of the preheating cover 1 is fixedly connected with a guide cover 7, the guide cover 7 is located below the dispersion outer cover 502, the bottom of the preheating cover 1 is provided with a guide port 12 communicated with the backflow pipe 4, and the guide cover 7 guides the preheated and dispersed powder to the guide port 12.

[0041] Through the upper and lower and around the distribution of the dispersion port 10, the spiral blade 203 conveying iron powder to the dispersion port 10 automatically dispersed from the conveying mechanism 2 to fall into the preheating cover 1, and matched with the outer side of the reciprocating dispersion assembly 6, through the driving motor 801 drive cam 802 rotation, reciprocating extrusion connecting ring 603, matched with the spring one 604 elasticity, so that the connecting rod 602 up and down reciprocating movement, thus driving the push ring 601 up and down reciprocating fast action, and the powder from the dispersion port 10 fall in the push ring 601 and dispersion inner cover 501 between the annular space, and when the push ring 601 moves up, push the bearing powder upward vibration dispersion, and the dispersed powder further fall in the dispersion cover 502 of the circular table surface, and along the dispersion cover 502 dispersion downward, during the cooperation with the heating pipe 15 to realize the iron powder heating, and in the preheating cover 1 inside the protective gas to complete the full preheating, and after preheating iron powder fall into the preheating cover 1 and guide cover 7 enclosed material area, and through the guide port 12 downward into the return pipe 4, and via the backflow port 11 after the preheated iron powder backflow filling to the conveying mechanism 2, and conveying mechanism 2 continue to convey, after the preheated iron powder downward to the conveying belt of the sintering furnace, complete the front stage continuous preheating.

[0042] In the embodiment 1, the protective gas is circulated into the whole closed cavity through the suction end 17 at the top and the extraction end 18 at the bottom of the preheating cover 1, the iron powder to be preheated is added through the feeding cylinder 3 at the top, the power mechanism in the feeding cylinder 3 is started to drive the rotating of the conveying shaft 202 and the spiral blade 203 of the conveying mechanism 2 to stably convey the iron powder into the conveying pipe 201 from top to bottom; when the iron powder is conveyed to the positions corresponding to the dispersion ports 10 in the conveying pipe 201, the powder flows out of the dispersion ports 10 and falls into the annular space formed by the pushing ring 601 and the dispersion inner cover 501, and the reciprocating driving part 8 at the bottom is started to drive the cam 802 to rotate through the connecting ring 603 and the connecting rod 602, so as to drive the whole reciprocating dispersion assembly 6 to perform high-frequency up-and-down reciprocating movement, on one hand, the upward movement throws the iron powder on the pushing ring 601 and diffuses it outward, so that the iron powder is evenly scattered on the conical surface of the dispersion outer cover 502 of the rotating multi-stage dispersion mechanism 5 below, on the other hand, the rotating motor 904 of the rotating support part 9 at the top drives the whole multi-stage dispersion mechanism 5 to slowly rotate through the gear 905 and the internal gear 906, the iron powder scattered on the dispersion outer cover 502 slowly slides along the inclined conical surface and rotates with the dispersion outer cover 502, and fully and dynamically exchanges heat with the heating pipe 15 fixed at the bottom of the dispersion outer cover 502 to realize rapid and uniform preheating; the iron powder preheated by one or more stages of dispersion is finally collected to the guide cover 7 along the guide cover 7, enters the backflow pipe 4 below through the guide port 12, and the movement of the reciprocating driving part 8 periodically knocks the backflow pipe 4 through the impact column 16 at the bottom of the connecting ring 603 to help the powder to smoothly flow back to the backflow port 11 of the conveying mechanism 2 through vibration, and then the powder is refilled into the conveying mechanism 2 and conveyed downward to the conveying belt of the sintering furnace again through the spiral blade 203 to complete the isolated preheating and the subsequent conveying.

[0043] The outer surface of the guide cover 7 is also a circular truncated cone surface to guide the powder and provide the effect of concentrated discharge.

[0044] The bottom of the connecting ring 603 is fixedly connected with the impact column 16, the impact column 16 corresponds to the backflow pipe 4 one by one, and the impact column 16 reciprocally impacts the backflow pipe 4 along with the reciprocating dispersion assembly 6.

[0045] The reciprocating dispersion assembly 6 reciprocates under the control of the reciprocating driving part 8, moves up and down with the connecting ring 603, and drives the bottom impact column 16 to reciprocally impact the corresponding backflow pipe 4, so as to realize the reciprocating vibration treatment of the backflow pipe 4 and the effective backflow of the preheated iron powder in the cavity.

[0046] The inside of the preheating cover 1 is rotatably provided with a rotating support part 9, which comprises a mounting ring 901, a top ring 902, a clamping ring 903, a rotating motor 904, a gear 905 and an internal gear 906. The top of the inner cavity of the preheating cover 1 is provided with an assembly ring groove 13. The clamping ring 903 is fixed to the outside of the top ring 902. The top ring 902 is fixed to the top of the mounting ring 901. The top ring 902 and the clamping ring 903 are rotatably sleeved in the assembly ring groove 13. The mounting ring 901 is fixed to the top of the multi-stage dispersion mechanism 5. The internal gear 906 is fixedly installed on the inner wall of the mounting ring 901. The rotating motor 904 is fixed to the top of the preheating cover 1. The gear 905 is located on the inside of the internal gear 906 and is in meshing connection with the internal gear 906. The gear 905 is fixedly installed on the output shaft of the rotating motor 904.

[0047] The rotating support part 9 is used to connect and support the multi-stage dispersion mechanism 5. The rotation of the internal gear 906 is driven by the gear 905, so as to control the rotation of the multi-stage dispersion mechanism 5. The rotation effect is used to further strengthen the dispersion effect of the powder falling from the top. The dynamic rotation of the dispersion outer cover 502 is used to further disperse the powder falling thereon under the action of friction force and centrifugal force, so as to improve the dispersion effect and effectively act on the heating pipe 15, thereby realizing rapid and uniform heating.

[0048] The clamping ring 903 and the top ring 902 cooperate with the assembly ring groove 13 to realize stable rotation and avoid upward and downward deviation. The middle rod 503 is used to connect and support the multiple sets of dispersion inner covers 501 and dispersion outer covers 502 distributed upward and downward.

[0049] The outer peripheral wall of the mounting ring 901 is fixedly connected with a cleaning rod 14, which is circumferentially distributed in the preheating cover 1 and movably attached to the inner wall of the preheating cover 1.

[0050] The rotating effect of the rotating support part 9 is further used to cooperate with the fixedly connected cleaning rod 14 to realize synchronous rotation cleaning of the inner wall of the preheating cover 1 during the rotation process, so as to effectively remove the attachments on the inner wall. The rotation process is used to complete the dispersion strengthening and the online continuous self-cleaning of the inner wall at the same time.

[0051] The preheating cover 1 is internally provided with a gas circulation mechanism, the gas circulation mechanism comprises a suction end 17, an extraction end 18, filter cloth one 19, filter cloth two 20 and a scraping piece 21, the extraction end 18 is communicated with the bottom of the preheating cover 1, the suction end 17 is communicated with the top of the preheating cover 1, the filter cloth one 19 is fixedly connected to the bottom of the suction end 17, the top of the extraction end 18 is towards the space surrounded by the guide cover 7, the filter cloth two 20 is symmetrically distributed on the outer side of the guide cover 7, the scraping piece 21 is fixedly connected to the bottom of the lowermost dispersion outer cover 502, the scraping piece 21 is in rotating contact with the outer side of the guide cover 7, the gas circulation mechanism further comprises a circulating pump, the extraction end 18 is communicated with the suction inlet of the circulating pump, the gas outlet of the circulating pump is communicated with the backflow end of the external gas source, and the suction end 17 is communicated with the leading end of the external gas source.

[0052] By utilizing the gas circulation mechanism, the internal filling gas is subjected to circulation treatment, the circulating pump (not shown in the figure) communicated with the extraction end 18 is used to extract and transport the gas in the preheating cover 1 to the gas source, the suction effect of the preheating cover 1 on the suction end 17 is used to further circulate the gas into the preheating cover 1 through the circulating pump and the gas source, and the internal gas is maintained to be dynamically sufficient.

[0053] The scraping piece 21 slides along the outer side of the guide cover 7 by following the rotation of the dispersion outer cover 502, the scraping piece 21 realizes scraping of the filter cloth two 20, ensures that the powder attached to the filter cloth two 20 is quickly separated when the gas is sucked out, and further abuts against the top of the inner cavity of the preheating cover 1 by following the rotating cleaning rod 14 in the rotating process, and intermittently scrapes the powder on the filter cloth one 19 in the rotating process. Embodiment

[0054] Online self-cleaning and gas circulation

[0055] During the whole preheating process, the rotation of the multistage dispersion mechanism 5 drives the synchronous rotation of the mounting ring 901 at the top of the multistage dispersion mechanism 5 and the cleaning rod 14 fixed thereon, the cleaning rod 14 continuously scrapes the inner wall of the preheating cover 1 to scrape off the possible adhered dust, realizes online self-cleaning, the gas circulation mechanism extracts the protective gas in the preheating cover 1 through the extraction end 18 at the bottom and in combination with the circulating pump and transports the protective gas to the gas source, the gas source with the gas storage capacity further replenishes the protective gas in the preheating cover 1 through the suction end 17, maintains the gas to be sufficient, and the scraping piece 21 at the bottom of the lowermost dispersion outer cover 502 also rotates synchronously to clean the filter cloth two 20 on the outer side of the guide cover 7, and keeps the protective gas circulation unobstructed.

[0056] Working principle and use flow of the application:

[0057] Feeding and closed conveying

[0058] First, by the suction end 17 at the top and the extraction end 18 at the bottom of the preheating cover 1, protective gas is circulated into the entire closed cavity, and the iron powder to be preheated is added through the top feed cylinder 3, the power mechanism in the feed cylinder 3 is started, and the conveying shaft 202 and the spiral blade 203 of the conveying mechanism 2 are driven to rotate, stably conveying the iron powder from top to bottom into the conveying pipe 201;

[0059] Dynamic dispersion and multi-stage circulation preheating

[0060] When the iron powder is conveyed in the conveying pipe 201 to the position corresponding to each stage of the dispersion port 10, the powder flows out of the dispersion port 10 and falls into the annular space formed by the push ring 601 and the dispersion inner cover 501, and the reciprocating drive part 8 at the bottom is started, which drives the cam 802 to rotate through the connecting ring 603 and the connecting rod 602, and drives the entire reciprocating dispersion assembly 6 to perform high-frequency up-and-down reciprocating motion:

[0061] On the one hand, the upward movement throws the iron powder on the push ring 601 and diffuses it outward, so that it is evenly scattered on the conical surface of the dispersion outer cover 502 of the rotating multi-stage dispersion mechanism 5 below;

[0062] On the other hand, the rotating motor 904 of the top rotating support part 9 drives the entire multi-stage dispersion mechanism 5 to rotate slowly through the gear 905 and the internal gear 906, and the iron powder scattered on the dispersion outer cover 502 slowly slides along the inclined conical surface while rotating, and fully and dynamically exchanges heat with the heating pipe 15 fixed at the bottom of the dispersion outer cover 502, achieving rapid and uniform preheating;

[0063] Backflow and recirculation

[0064] After being dispersed and heated by one or more stages, the iron powder finally collects along the guide cover 7 to the guide port 12, enters the backflow pipe 4 below, and the movement of the reciprocating drive part 8 periodically knocks the backflow pipe 4 through the impact column 16 at the bottom of the connecting ring 603, and the powder smoothly flows back to the backflow port 11 of the conveying mechanism 2 through vibration, is refilled into the conveying mechanism 2, and is again conveyed downward by the spiral blade 203 to the conveying belt of the sintering furnace.

[0065] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A continuous preheating structure of an iron powder sintering furnace, comprising a preheating cover (1), characterized in that: The inside of the preheating cover (1) is fixedly provided with a conveying mechanism (2), the top of the conveying mechanism (2) is provided with a feeding cylinder (3), the bottom of the preheating cover (1) is provided with a backflow pipe (4) in communication with the conveying mechanism (2), a plurality of stage dispersion mechanisms (5) are rotatably arranged in the preheating cover (1), a reciprocating dispersion assembly (6) is arranged outside the conveying mechanism (2), the reciprocating dispersion assembly (6) is arranged inside the plurality of stage dispersion mechanisms (5), the plurality of stage dispersion mechanisms (5) are provided with heating pipes (15) arranged around, and the preheating cover (1) is filled with protective gas; The conveying mechanism (2) is used for conveying the iron powder in the inside to the preheating cover (1), the reciprocating dispersion assembly (6) is used for dispersing the iron powder input into the preheating cover (1) on the plurality of stage dispersion mechanisms (5), and the plurality of stage dispersion mechanisms (5) are used for dispersing and guiding the iron powder to flow back to the conveying mechanism (2) through the backflow pipe (4); The conveying mechanism (2) comprises a conveying pipe (201), a conveying shaft (202) and a spiral blade (203), the conveying shaft (202) is rotatably sleeved in the conveying pipe (201), the spiral blade (203) is fixedly arranged on the conveying shaft (202), the conveying pipe (201) is fixedly communicated in the inside of the feeding cylinder (3), the inside of the feeding cylinder (3) is provided with a power mechanism, the output shaft of the power mechanism is fixedly connected with the conveying shaft (202), and the pipe wall of the conveying pipe (201) is also provided with a dispersion port (10) and a backflow port (11), the backflow port (11) is in communication with the backflow pipe (4), and the dispersion ports (10) are arranged on the outside of the conveying pipe (201) from top to bottom; The plurality of stage dispersion mechanisms (5) comprise a dispersion inner cover (501), a dispersion outer cover (502) and an intermediate rod (503), the dispersion outer cover (502) is fixedly arranged outside the dispersion inner cover (501), the top of the dispersion outer cover (502) is a circular table face, the intermediate rod (503) is fixedly arranged inside each dispersion outer cover (502), the number and position of the dispersion inner covers (501) are matched with the number and position of the dispersion ports (10), and the heating pipes (15) are fixedly arranged around the bottom of the dispersion outer cover (502). The reciprocating dispersion assembly (6) comprises a pushing sleeve (601), a connecting rod (602), a connecting ring (603) and a spring (604), the pushing sleeve (601) is movably sleeved outside the conveying pipe (201) and movably sleeved inside the dispersion inner cover (501), the connecting rod (602) is sequentially fixed through each pushing sleeve (601), the pushing sleeve (601) corresponds to the dispersion inner cover (501), the connecting ring (603) is located below the preheating cover (1), the bottom end of the connecting rod (602) movably penetrates through the preheating cover (1) and is fixedly connected with the connecting ring (603), one end of the spring (604) is fixed on the connecting ring (603), and the other end of the spring (604) is fixed on the bottom of the preheating cover (1), and the pushing sleeves (601) are staggered above and below the dispersion ports (10). The reciprocating driving part (8) is arranged between the return pipes (4), the reciprocating driving part (8) comprises a driving motor (801) and a cam (802), the cam (802) is fixedly installed on the output shaft of the driving motor (801), the driving motor (801) is fixed between the return pipes (4) through an external support, and the cam (802) is located at the bottom of the connecting ring (603) and abuts against the connecting ring (603). The bottom of the connecting ring (603) is fixedly connected with an impact column (16), the impact column (16) corresponds to the return pipe (4), and the impact column (16) reciprocally impacts the return pipe (4) following the reciprocating dispersion assembly (6).

2. A continuous preheating structure of a sintering furnace for iron powder according to claim 1, characterized in that: The preheating cover (1) is fixedly connected with a guide cover (7) in the inside, the guide cover (7) is located below the dispersion outer cover (502), the bottom of the preheating cover (1) is provided with a through port (12) in communication with the return pipe (4), and the guide cover (7) guides the powder preheated and dispersed to the through port (12).

3. A continuous preheating structure of a sintering furnace for iron powder according to claim 2, characterized in that: The preheating cover (1) is rotatably provided with a rotating support part (9) in the inside, the rotating support part (9) comprises a mounting ring (901), a top ring (902), a clamping ring (903), a rotating motor (904), a gear (905) and an internal gear (906), a mounting ring groove (13) is formed in the top of the preheating cover (1), the clamping ring (903) is fixed outside the top ring (902), the top ring (902) is fixed on the top of the mounting ring (901), the top ring (902) and the clamping ring (903) are rotatably sleeved in the mounting ring groove (13), the mounting ring (901) is fixed on the top of the multi-stage dispersion mechanism (5), the internal gear (906) is fixedly installed on the inner wall of the mounting ring (901), the rotating motor (904) is fixed on the top of the preheating cover (1), the gear (905) is located inside the internal gear (906) and is in meshing connection with the internal gear (906), and the gear (905) is fixedly installed on the output shaft of the rotating motor (904).

4. A continuous preheating structure of a sintering furnace for iron powder according to claim 3, wherein: The outer peripheral wall of the mounting ring (901) is fixedly connected with a cleaning rod (14) which is distributed around the preheating cover (1) and is movably attached to the inner wall of the preheating cover (1).

5. A continuous preheating structure of a sintering furnace for iron powder according to claim 4, characterized in that: The preheating cover (1) is internally provided with a gas circulation mechanism which comprises a suction end (17), an exhaust end (18), a filter cloth I (19), a filter cloth II (20) and a scraping member (21). The exhaust end (18) is communicatively arranged at the bottom of the preheating cover (1), the suction end (17) is communicatively arranged at the top of the preheating cover (1), the filter cloth I (19) is fixedly connected at the bottom of the suction end (17), the top of the exhaust end (18) faces the space surrounded by the guide cover (7), the filter cloth II (20) is symmetrically distributed on the outer side of the guide cover (7), the scraping member (21) is fixedly connected at the bottom of the lowermost dispersion outer cover (502), the scraping member (21) is in rotational contact with the outer side of the guide cover (7), and the gas circulation mechanism further comprises a circulating pump. The exhaust end (18) is in communication with the suction inlet of the circulating pump, the gas outlet of the circulating pump is in communication with the backflow end of an external gas source, and the suction end (17) is in communication with the leading end of the external gas source.

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