Preheater capable of preventing tail end of screw shaft from being abraded

Abstract

The invention relates to the technical field of carbon anode manufacturing, and discloses a preheater capable of preventing the tail end of a screw shaft from being abraded, which comprises a box body, the screw shaft, a transmission mechanism and a heat conduction oil inlet and outlet system, graphite bearings are arranged at the tail ends of the spiral shafts; the transmission mechanism is installed outside the box body and connected with the tail end of the spiral shaft through a transmission gear. A cylindrical wear-resistant shaft sleeve is arranged between the tail end of the spiral shaft and the graphite bearing, and a plurality of fixing holes used for being fixed to the tail end of the spiral shaft are evenly distributed in the two ends of the wear-resistant shaft sleeve in the circumferential direction; the wear-resistant shaft sleeve is a steel sleeve, and the outer diameter of the wear-resistant shaft sleeve is the same as the inner diameter of the graphite bearing; the technical problem that in the prior art, due to contact abrasion of a spiral shaft and a graphite bearing, maintenance work of a preheater is complex and time-consuming is solved.

Description

Technical Field

[0001] The invention relates to the technical field of carbon anode manufacturing, and in particular to a preheating machine capable of preventing the end of a spiral shaft from being worn. Background Art

[0002] Preheater is mainly used to preheat materials to improve the efficiency and quality of subsequent processing. In the production process of carbon anode, preheater plays a vital role. Carbon anode is an indispensable material in the aluminum electrolysis industry. Its production process includes crushing, screening, batching, kneading, molding, roasting and other links, and preheater is located in the key position between molding and roasting.

[0003] The main function of the preheater is to heat and stir the material to a certain temperature and uniformity to prepare for the subsequent roasting process. Inside the preheater, the material is filled in the box, and the spiral shaft rotates and stirs to achieve uniform heating and mixing of the material.

[0004] As the supporting part of the end of the spiral shaft, the graphite bearing is subjected to large resistance and torque during operation due to the filling of materials inside the box, and also bears its own weight, which causes large relative friction between the graphite bearing and the spiral shaft. As time goes by, the wear rate of the graphite bearing gradually accelerates. Once the wear exceeds its thickness, the end of the spiral shaft will directly contact the sealing gland on the side of the graphite bearing. This contact will not only cause wear at the end of the spiral shaft, but also cause the spiral shaft as a whole to sink.

[0005] Once the problem of spiral shaft sinking occurs, it will lead to a series of serious consequences. First, the friction between the spiral shaft and the bottom box will cause the wear of the spiral shaft surface to increase, and may even cause wear of the spiral shaft blades or cracking of the welds. These wear and cracking phenomena will not only reduce the operating efficiency of the preheater, but also seriously affect the service life of the preheater. Secondly, the sinking of the spiral shaft may also cause leakage of heat transfer oil. The interior of the preheater is usually filled with heat transfer oil, which is used to heat and cool the spiral shaft and the materials inside the box. Once the heat transfer oil leaks in the spiral shaft or the shell cavity, it will not only seriously affect the normal operation of the preheater, but may also cause serious consequences such as fire, posing a huge threat to production safety and personnel safety.

[0006] In order to deal with the problems of spiral shaft wear and sinking, the traditional solution is to regularly replace and maintain the worn parts. However, this process involves the disassembly and installation of all components of the preheater, which is not only complicated but also requires a high level of technical personnel. In addition, since the disassembly and installation work is time-consuming, the replacement cycle is often long, which will undoubtedly delay the production period and increase production costs. At the same time, the repeated disassembly and installation of the spiral shaft may also increase the risk of human operation, further exacerbating the degree of damage to the equipment. Summary of the invention

[0007] The present invention is intended to provide a preheating machine which can prevent the wear of the end of the screw shaft, so as to solve the technical problem in the prior art that the maintenance of the preheating machine is complicated and time-consuming due to the contact wear between the screw shaft and the graphite bearing.

[0008] To achieve the above object, the present invention adopts the following technical solution: a preheating machine capable of preventing wear on the end of a screw shaft, comprising a housing, a screw shaft, a transmission mechanism and a heat transfer oil inlet and outlet system;

[0009] The box is used to contain materials, and is provided with a feeding port and a discharging port; there are four spiral shafts, which are horizontally and parallelly installed in the box, and a heat transfer oil channel is provided inside the spiral shaft. Spiral blades are welded on the outer surface of the spiral shaft, and a graphite bearing is provided at the end of the spiral shaft; the transmission mechanism is installed outside the box and connected to the end of the spiral shaft through a transmission gear; the heat transfer oil inlet and outlet system is used to transport high-temperature heat transfer oil into the spiral shaft, and the heat transfer oil inlet and outlet system is connected to the heat transfer oil channel in the spiral shaft;

[0010] A wear-resistant sleeve is arranged between the end of the spiral shaft and the graphite bearing. The wear-resistant sleeve is cylindrical, and multiple fixing holes for fixing to the end of the spiral shaft are evenly distributed along the circumference at both ends of the wear-resistant sleeve; the outer diameter of the wear-resistant sleeve is the same as the inner diameter of the graphite bearing.

[0011] The principle and advantages of this solution are: the wear-resistant sleeve acts as an intermediary between the screw shaft and the graphite bearing, and bears most of the friction and wear caused by the rotation of the screw shaft;

[0012] The wear-resistant sleeve is tightly connected to the end of the spiral shaft through a fixing hole to ensure that it will not loosen or fall off during rotation. The outer diameter of the wear-resistant sleeve matches the inner diameter of the graphite bearing, ensuring a close fit between the two and reducing relative friction. When the wear-resistant sleeve needs to be replaced due to long-term wear, the graphite bearing and the wear-resistant sleeve are both located outside the box. When replacing, there is no need to disassemble the internal components of the preheater, and the operation only needs to be performed outside the box, which greatly simplifies the replacement process and reduces technical difficulty and working hours.

[0013] The use of wear-resistant sleeves effectively reduces the wear on the end of the screw shaft and extends the service life of the screw shaft and graphite bearing; at the same time, by avoiding frequent disassembly and installation of the screw shaft, the risk of equipment damage caused by improper human operation is also reduced.

[0014] Preferably, as an improvement, the spiral shaft includes an internally hollow dry pipe and spiral blades fixedly welded to the outside of the dry pipe, the dry pipe includes an oil inlet chamber and an oil outlet chamber, one end of the dry pipe is provided with a through opening connected to the heat transfer oil inlet and outlet system, and the other end of the dry pipe is closed; the through opening of the dry pipe is a double-layer pipe opening, the inner pipe opening of the through opening is connected to the oil inlet chamber through an extension pipe, and the outer pipe opening of the through opening is connected to the oil outlet chamber.

[0015] The beneficial effects of this improvement are as follows: by installing the transmission mechanism at the closed end of the spiral shaft and connecting the heat transfer oil inlet and outlet system to the through-port end, the two are effectively isolated in space; such a layout avoids the mutual interference that may occur between the transmission mechanism and the heat transfer oil inlet and outlet system during operation, thereby improving the overall stability and reliability of the preheater; the clear separation of the oil inlet chamber and the oil outlet chamber and the design of the double-layer pipe mouth make the circulation path of the heat transfer oil inside the spiral shaft more reasonable and efficient; due to the spatial isolation of the transmission mechanism and the heat transfer oil inlet and outlet system and the design of the double-layer pipe mouth, it is more convenient and quick to replace or maintain the spiral shaft and its related components, and technicians can easily complete the replacement or maintenance work without disassembling the complex internal structure.

[0016] Preferably, as an improvement, the spiral blade is hollow, and the spiral blade and the outer surface of the main pipe form a surrounding channel, the oil inlet chamber is close to the closed end of the main pipe, the oil outlet chamber is close to the open end of the main pipe, and the oil outlet chamber and the oil inlet chamber are adjacent to each other, and a first flow hole connecting the oil inlet chamber and the surrounding channel is provided on the main pipe near the closed end, and a second flow hole connecting the oil outlet chamber and the surrounding channel is provided on the main pipe near the open end.

[0017] The beneficial effects of this improvement are as follows: since the spiral blades are hollow and form a surrounding channel with the outer surface of the main pipe, the heat transfer oil can flow inside the spiral blades and exchange with the surrounding channel through the first flow hole and the second flow hole; the indirect contact surface between the heat medium oil and the material is increased, and the heat dissipation efficiency is improved; after the heat transfer oil enters the interior of the spiral shaft from the oil inlet chamber, it first flows into the surrounding channel of the spiral blade through the first flow hole to heat the spiral blade. Subsequently, the heat transfer oil continues to flow and returns to the oil outlet chamber through the second flow hole, and finally flows out of the spiral shaft. In this process, the heat flows from the inside of the spiral shaft to the outside in one direction, avoiding the waste caused by the cold oil absorbing the hot oil energy.

[0018] Preferably, as an improvement, the preheater also includes a rotary joint for connecting the spiral shaft and the heat transfer oil inlet and outlet system, the rotary joint includes a shell, a first bearing and a second bearing, a first bearing chamber for placing the first bearing and a second bearing chamber for placing the second bearing are provided in the shell, the main pipe is rotatably connected to the first bearing, and the extension pipe extends from the main pipe and is rotatably connected to the second bearing.

[0019] The beneficial effect of this improvement is that the rotary joint can meet the connection requirements of the double-layer pipe mouth structure of the spiral shaft opening, so that when the spiral shaft rotates, the heat medium oil of the inner pipe and the outer pipe can still be stably transported to and from different pipelines; the leakage of the heat transfer oil during the rotation process is prevented, thereby ensuring the stable operation of the preheater.

[0020] Preferably, as an improvement, the outer ring of the first bearing is fixedly connected to the first bearing chamber, the inner side of the inner ring of the first bearing is integrally provided with a first connecting pipe fixedly connected to the main pipe, and a connecting pipe tightly fitted with the inner wall of the first connecting pipe is further provided in the housing, one end of the connecting pipe is fixedly connected to the housing, and the other end of the connecting pipe extends out of the housing and probes into the inner wall of the main pipe;

[0021] The outer ring of the second bearing is fixedly connected to the second bearing chamber. The housing is integrally formed with a second connecting pipe extending toward the first bearing chamber at the position of the second bearing chamber. The second connecting pipe is sleeved on the outer wall of the extension pipe and fixedly connected thereto.

[0022] The beneficial effect of this improvement is that through the design of the first connecting pipe and the second connecting pipe, the main pipe and the extension pipe can be stably fixedly connected to the first bearing and the second bearing respectively, thereby improving the overall stability and durability of the rotary joint; the close fit between the connecting pipe and the first connecting pipe and the fixed connection between the second connecting pipe and the extension pipe both help prevent the leakage of heat transfer oil inside the rotary joint, avoid the bearing from being damaged by high-temperature hot oil, and further ensure the sealing performance of the preheater.

[0023] Preferably, as an improvement, an oil outlet pipe is provided on the shell between the first bearing chamber and the second bearing chamber, and an oil inlet pipe is provided on the shell along the spiral axis; the connecting pipe and the extension pipe in the rotary joint form a closed space for connecting the oil outlet cavity and the oil outlet pipe, and the extension pipe extends into the oil inlet pipe and fits tightly with the oil inlet pipe.

[0024] The beneficial effect of this improvement is that the oil inlet pipe and the oil outlet pipe can be respectively connected to different flow direction pipes of the heat transfer oil in and out of the system, and the extension pipe extends into the oil inlet pipe, further avoiding leakage of the heat transfer oil.

[0025] Preferably, as an improvement, the inner wall of the extension tube is provided with an internal thread structure; the wear-resistant sleeve is a steel sleeve, the inner diameter of the wear-resistant sleeve is 140mm, the outer diameter is 160mm, and the barrel length is 240mm; the inner diameter of the graphite bearing is 160mm.

[0026] The beneficial effects of this improvement are: during the rotation of the spiral shaft and the flow of hot oil, the hot oil is guided to form a vortex, which significantly accelerates the flow speed of the hot oil and further improves the heating efficiency; the wear-resistant sleeve is made of high-strength, high-wear-resistant steel, and has sufficient hardness and toughness to resist the resistance and torque during the operation of the spiral shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a cross-sectional view of a wear-resistant sleeve according to an embodiment of the present invention.

[0028] Figure 2 It is a schematic structural diagram of a wear-resistant sleeve according to an embodiment of the present invention.

[0029] Figure 3 2 is a cross-sectional view of a spiral shaft according to an embodiment of the present invention.

[0030] Figure 4 It is a cross-sectional view of a rotary joint according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following is further described in detail through specific implementation methods:

[0032] The figure marks in the drawings of the specification include: wear-resistant sleeve 1, fixing hole 2, oil inlet chamber 3, oil outlet chamber 4, spiral blade 5, surrounding channel 6, main pipe 7, extension pipe 8, housing 9, first bearing 10, second bearing 11, connecting pipe 12, first connecting pipe 13, second connecting pipe 14, oil inlet pipe 15 and oil outlet pipe 16.

[0033] Example

[0034] A preheating machine capable of preventing the end of a spiral shaft from being worn comprises a box body, a spiral shaft, a transmission mechanism and a heat transfer oil inlet and outlet system.

[0035] The box is welded from steel plates and has sufficient strength and rigidity. The box can be rectangular or U-shaped, and the internal space is used to accommodate the screw shaft and materials. The box is equipped with a feeding port, a discharge port, an observation window, a temperature measurement hole, etc., so as to facilitate operations such as feeding, discharging, observation and temperature measurement.

[0036] The spiral shaft is made of a hollow steel pipe, and a heat transfer oil channel is provided inside for passing high-temperature heat transfer oil for heating. A spiral blade 5 is welded on the outer surface of the spiral shaft; a graphite bearing and a sealing device for supporting the spiral shaft are provided at the end of the spiral shaft to ensure stability and sealing during rotation. The spiral shaft is installed inside the box body, maintaining a certain gap with the side wall and bottom of the box body. There are four spiral shafts, and the four spiral shafts are installed horizontally and in parallel in the box body for normal rotation and conveying operations. Adjacent spiral shafts rotate in opposite directions. In this embodiment, the four spiral shafts rotate from left to right in clockwise, counterclockwise, clockwise, and counterclockwise directions.

[0037] The transmission mechanism includes a motor, a reducer and a transmission gear. The motor provides power for the screw shaft to rotate. The motor output is connected to the reducer input, and the reducer output is connected to the transmission gear input. The transmission gear is connected to the end of the screw shaft. The speed is reduced and the torque is increased by the reducer, and then the power is transmitted to the screw shaft through the transmission gear. The transmission mechanism is installed on the outside of the box and is located on one side of the end of the screw shaft. The transmission gear of the transmission mechanism is connected to the end of the screw shaft through a coupling or a universal joint, so that the power transmission value of the transmission mechanism is the screw shaft.

[0038] The heat transfer oil inlet and outlet system includes a heat transfer oil pipeline, a valve and a pump. The heat transfer oil pipeline is used to transport the high-temperature heat transfer oil from the heating system to the inside of the spiral shaft and the box, and transport the heat transfer oil after heat transfer and cooling back to the heating system for reheating. The valve is installed in the heat transfer oil pipeline to control the flow and direction of the heat transfer oil to ensure the stability and safety of the preheating process. The pump is connected to the heat transfer oil pipeline to provide the power required for the heat transfer oil circulation. The heat transfer oil inlet and outlet system is usually installed on the side or bottom of the box, and is connected to the spiral shaft and the inside of the box.

[0039] Due to the filling of materials inside the box, the spiral shaft is subjected to greater resistance and torque during operation, and its own weight causes the wear rate of the graphite bearing at the end of the spiral shaft to accelerate. Once the wear exceeds the thickness of the graphite bearing, the end of the spiral shaft will directly contact the sealing gland at the side end of the graphite bearing, which will cause wear of the end of the spiral shaft and the sinking of the spiral shaft as a whole. This sinking will not only cause the spiral shaft to rub against the bottom box, but also cause wear of the spiral shaft blades or cracking of the weld. If the wear and sinking problems of the spiral shaft are not repaired in time, they will eventually lead to leakage of the heat transfer oil in the spiral shaft or the housing 9 cavity. Once the heat transfer oil leaks, it will not only affect the normal operation of the preheater, but may also cause serious consequences such as fire, posing a huge threat to production safety and personnel safety.

[0040] The process of repairing the wear on the end of the spiral shaft is extremely complicated. It requires disassembling several key components of the preheater, such as the drive end motor, reducer, gearbox and graphite bearing seat, and lifting the spiral shaft out of the box as a whole. During the repair process, multiple repair welding, measurement and grinding are required, and the welding temperature is strictly controlled to prevent the end of the spiral shaft from deforming. This repair process is not only time-consuming, but also requires a very high level of technical skills from the operator. If the spiral shaft is severely worn to the point of breaking or the weld is open, the entire spiral shaft needs to be replaced. This process not only involves the disassembly and installation of all components of the preheater, but also requires the old shaft to be hoisted from the fifth floor of the high-rise building to the ground, and then the new shaft to be hoisted from the ground to the fifth floor. This hoisting operation is not only difficult, but also the equipment rental fee is high, which has brought a heavy burden to the company's production and operation.

[0041] In order to extend the service life of the screw shaft and reduce the maintenance cost of the screw shaft, a wear-resistant sleeve 1 is arranged between the end of the screw shaft and the graphite bearing.

[0042] As attached Figure 1 and attached Figure 2 As shown, the wear-resistant sleeve 1 is cylindrical and is sleeved at the end of the spiral shaft, and is in direct contact with the inner ring of the graphite bearing, so that when the spiral shaft generates rotation resistance, relative friction occurs due to the direct contact between the wear-resistant sleeve 1 and the graphite bearing, thereby avoiding direct wear of the spiral shaft. In addition, during the maintenance of the spiral shaft, only the wear-resistant sleeve 1 and the graphite bearing of the spiral shaft need to be replaced from the outside of the box, which greatly reduces the maintenance time and repair cost.

[0043] The inner diameter of the wear-resistant sleeve 1 is 140mm, the outer diameter is 160mm, and the length of the barrel is 240mm. The wear-resistant sleeve 1 is a steel sleeve, so the size of the original graphite bearing needs to be improved, and the inner diameter of the graphite bearing is changed to 160mm to match the wear-resistant sleeve 1. In order to facilitate the rotation of the sleeve on the spiral shaft, 45° chamfers are set at both ends of the inner side of the wear-resistant sleeve 1 to facilitate the spiral shaft to slide into the wear-resistant sleeve 1. And multiple M8 fixing holes 2 are evenly distributed along the circumference at both ends of the wear-resistant sleeve 1. The M8 fixing holes 2 are internal threaded holes with a thread diameter of 8mm. Six M8 fixing holes 2 are provided on a single wear-resistant sleeve 1, of which three are evenly arranged in a group along the circumference of the barrel wall of the wear-resistant sleeve 1. Two groups of M8 fixing holes 2 are respectively located at both ends of the wear-resistant sleeve 1 and are symmetrically arranged. The screw passes through the M8 fixing hole 2, so that the wear-resistant sleeve 1 and the end of the spiral shaft are tightly fixed to avoid relative friction between the two. When assembling the wear-resistant sleeve 1 and the graphite bearing, heating, tapping and other operations are adopted to make the wear-resistant sleeve 1 fit tightly with the inner ring of the graphite bearing.

[0044] In order to increase the heating power of the preheater, the spiral shaft of the preheater is improved:

[0045] As attached Figure 3 As shown, the spiral shaft includes a hollow main pipe 7 and spiral blades 5 fixedly welded to the outside of the main pipe 7;

[0046] A flow channel for the circulation of the heat medium oil is provided in the main pipe 7 , and the flow channel is subdivided into two parts, an oil inlet chamber 3 and an oil outlet chamber 4 , which are arranged adjacent to each other.

[0047] One end of the dry pipe 7 is designed as a through hole arranged along the central axis. This through hole is directly connected to the external heat transfer oil inlet and outlet system to ensure the smooth flow of the heat transfer oil. The other end of the dry pipe 7 is closed so that the heat transfer oil flows in and out of the flow channel on one side of the dry pipe 7, leaving space for the installation of the transmission mechanism, effectively avoiding the mutual interference between the heat transfer oil flow and the transmission mechanism layout.

[0048] The oil inlet chamber 3 is arranged near the closed end of the trunk pipe 7, and the oil outlet chamber 4 is arranged near the through end of the trunk pipe 7. The through opening of the trunk pipe 7 is a double-layer pipe opening, the inner pipe opening of the through opening is connected to the oil inlet chamber 3 through the extension pipe 8, and the outer pipe opening of the through opening is connected to the oil outlet chamber 4.

[0049] The spiral blade 5 also adopts a hollow design, and together with the outer surface of the dry pipe 7, forms a surrounding channel 6 for further circulation and heat dissipation of the heat medium oil. A second flow hole connected to the surrounding channel 6 in the spiral blade 5 is provided near the opening end of the oil outlet chamber 4; and in the oil inlet chamber 3, a first flow hole connected to the oil inlet chamber 3 and the surrounding channel 6 is provided near the closed end of the dry pipe 7. This design ensures that the heat medium oil can form an effective circulation flow between the dry pipe 7 and the spiral blade 5.

[0050] The heat transfer oil first enters the oil inlet chamber 3 through the inner pipe opening, that is, through the extension pipe 8, and then flows axially to the first flow hole and enters the surrounding channel 6 of the spiral blade 5. In the surrounding channel 6, the heat transfer oil fully releases heat to the material in the box to increase the temperature of the material. After the heat exchange is completed, the heat transfer oil with reduced temperature returns to the oil outlet chamber 4 through the second flow hole, and finally flows out from the outer pipe opening, re-enters the heat transfer oil inlet and outlet system for reheating, forming a closed loop.

[0051] Inside the spiral shaft, the temperature distribution of the hot medium oil shows a trend of gradually decreasing from the inside to the outside, ensuring that the heat transfer direction always diffuses outward, maximizing contact with the material and improving the heat transfer efficiency. The hot oil flow design effectively avoids the adverse effect of the hot medium oil that has completed heat dissipation on the temperature of the hot medium oil that is about to perform heat transfer, thereby improving the overall heating efficiency.

[0052] An internal thread structure is added to the inner wall of the extension tube 8. This design guides the hot oil to form a vortex during the rotation of the spiral shaft and the flow of the hot oil, which significantly accelerates the flow speed of the hot oil and further improves the heating efficiency.

[0053] Since the external heat transfer oil inlet and outlet system is fixed, and the spiral shaft is in a rotating state when working, in order to make the pipe bodies in the two states connect, a rotary joint is used to connect the opening of the spiral shaft with the heat transfer oil inlet and outlet system. In order to support the needs of different flow directions on one side of the spiral shaft (that is, the double-layer pipe opening design of the opening).

[0054] As attached Figure 4 As shown, the structure of the rotary joint is specifically as follows:

[0055] The rotary joint includes a housing 9, a first bearing 10 and a second bearing 11. The housing 9 is provided with a first bearing chamber for mounting the first bearing 10 and a second bearing chamber for mounting the second bearing 11. The first bearing chamber and the second bearing chamber are sequentially arranged along the axial direction of the screw shaft.

[0056] The main pipe 7 is rotatably connected to the first bearing 10 in the first bearing chamber, and the extension pipe 8 extends from the main pipe 7 and is rotatably connected to the second bearing 11 in the second bearing chamber.

[0057] The outer ring of the first bearing 10 is fixedly connected to the first bearing chamber, and the inner ring of the first bearing 10 is integrally formed with a first connecting pipe 13 extending toward the housing 9. The first connecting pipe 13 is fixedly connected to the main pipe 7. A connecting pipe 12 is also provided in the housing 9, which is closely attached to the inner wall of the first connecting pipe 13. One end of the connecting pipe 12 is fixedly connected to the inner surface of the housing 9, and the other end of the connecting pipe 12 extends out of the housing 9 and penetrates into the inner wall of the main pipe 7. The outer wall of the connecting pipe 12 is closely attached to the inner wall of the main pipe 7. A sealing ring is provided between the connecting pipe 12 and the main pipe 7, and the sealing ring is located at the connection between the main pipe 7 and the first bearing 10. A flange is provided on the outside of the connection between the main pipe 7 and the first bearing 10, and a sealing ring is also provided on the inside of the flange to wrap the outer surface of the connection between the main pipe 7 and the first bearing 10.

[0058] The housing 9 between the first bearing chamber and the second bearing chamber is provided with an oil outlet pipe 16, which is connected to the pipeline of the heat transfer oil inlet and outlet system to the heating component. The connecting pipe 12 and the extension pipe 8 in the rotary joint form a closed space for connecting the oil outlet chamber 4 and the oil outlet pipe 16.

[0059] The outer ring of the second bearing 11 is fixedly connected to the second bearing chamber, and the housing 9 is integrally formed with a second connecting pipe 14 extending toward the first bearing chamber at the position of the second bearing chamber; the inner ring of the second bearing 11 is fixedly connected to the extension pipe 8, and the second connecting pipe 14 is sleeved on the outer wall of the extension pipe 8 and fixedly connected thereto. A sealing ring is provided between the second connecting pipe and the extension pipe 8.

[0060] The shell 9 is provided with an oil inlet pipe 15 along the spiral axis, and the oil inlet pipe 15 is connected with the pipe for the heat transfer oil to enter and exit the system from the heating component. The extension pipe 8 extends into the oil inlet pipe 15 and fits tightly with the oil inlet pipe 15; a sealing ring is also provided between the extension pipe 8 and the oil inlet pipe 15. In this embodiment, the sealing ring is made of hard sealing graphite ribbon fiber component, so that it has good sealing performance and can withstand a high temperature of 300 degrees Celsius.

[0061] In the rotary joint, the extension pipe 8 directly connects the oil inlet pipe 15 with the oil inlet chamber 3. When the spiral shaft is working, the main pipe 7, the extension pipe 8, the inner ring of the first bearing 10 and the inner ring of the second bearing 11 rotate at the same frequency as the spiral shaft. The housing 9 of the rotary joint, the outer ring of the first bearing 10, the outer ring of the second bearing 11 and the connecting pipe 12 remain stationary to ensure stable connection with the external heat transfer oil inlet and outlet system.

[0062] The hot oil in the heat transfer oil inlet and outlet system that has been heated flows into the rotary joint through the oil inlet pipe 15, and then enters the oil inlet chamber 3 in the spiral shaft through the extension pipe 8. The cold oil in the spiral shaft that has completed the heat transfer flows out through the dry pipe 7, enters the oil outlet pipe 16 through the connecting pipe 12, and finally flows back to the heat transfer oil inlet and outlet system for reheating.

[0063] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A preheating machine capable of preventing wear on the end of a screw shaft, characterized in that: It includes a box body, a screw shaft, a transmission mechanism and a heat transfer oil inlet and outlet system; The box body is used to contain materials, and is provided with a feeding port and a discharging port; there are four spiral shafts, which are installed horizontally and in parallel in the box body, a heat transfer oil channel is provided inside the spiral shaft, a spiral blade is welded on the outer surface of the spiral shaft, and a graphite bearing is provided at the end of the spiral shaft; the transmission mechanism is installed outside the box body and is connected to the end of the spiral shaft through a transmission gear; the heat transfer oil inlet and outlet system is used to transport high-temperature heat transfer oil into the spiral shaft, and the heat transfer oil inlet and outlet system is connected to the heat transfer oil channel in the spiral shaft; a wear-resistant sleeve is provided between the end of the spiral shaft and the graphite bearing, and the wear-resistant sleeve is cylindrical, and a plurality of fixing holes for fixing to the end of the spiral shaft are evenly distributed along the circumferential direction at both ends of the wear-resistant sleeve; the outer diameter of the wear-resistant sleeve is the same as the inner diameter of the graphite bearing.

2. A preheating machine capable of preventing wear on the end of a screw shaft according to claim 1, characterized in that: The spiral shaft includes a dry pipe with a hollow interior and spiral blades fixedly welded to the outside of the dry pipe. The dry pipe includes an oil inlet chamber and an oil outlet chamber. One end of the dry pipe is provided with a through opening connected to the heat transfer oil inlet and outlet system, and the other end of the dry pipe is closed. The through opening of the dry pipe is a double-layer pipe opening, the inner pipe opening of the through opening is connected to the oil inlet chamber through an extension pipe, and the outer pipe opening of the through opening is connected to the oil outlet chamber.

3. A preheating machine capable of preventing wear on the end of the screw shaft according to claim 2, characterized in that: The spiral blade is hollow and forms a surrounding channel with the outer surface of the main pipe. The oil inlet chamber is close to the closed end of the main pipe, and the oil outlet chamber is close to the open end of the main pipe. The oil outlet chamber and the oil inlet chamber are adjacent to each other. A first flow hole connecting the oil inlet chamber and the surrounding channel is provided on the main pipe near the closed end, and a second flow hole connecting the oil outlet chamber and the surrounding channel is provided on the main pipe near the open end.

4. A preheating machine capable of preventing wear on the end of the screw shaft according to claim 3, characterized in that: The preheater also includes a rotary joint for connecting the spiral shaft and the heat transfer oil inlet and outlet system, the rotary joint includes a shell, a first bearing and a second bearing, a first bearing chamber for accommodating the first bearing and a second bearing chamber for accommodating the second bearing are provided in the shell, the main pipe is rotatably connected to the first bearing, and the extension pipe extends from the main pipe and is rotatably connected to the second bearing.

5. A preheating machine capable of preventing wear on the end of the screw shaft according to claim 4, characterized in that: The outer ring of the first bearing is fixedly connected to the first bearing chamber, the inner side of the inner ring of the first bearing is integrally provided with a first connecting pipe fixedly connected to the main pipe, and the housing is also provided with a connecting pipe tightly fitted with the inner wall of the first connecting pipe, one end of the connecting pipe is fixedly connected to the housing, and the other end of the connecting pipe extends out of the housing and probes into the inner wall of the main pipe; The outer ring of the second bearing is fixedly connected to the second bearing chamber. The housing is integrally formed with a second connecting pipe extending toward the first bearing chamber at the position of the second bearing chamber. The second connecting pipe is sleeved on the outer wall of the extension pipe and fixedly connected thereto.

6. A preheating machine capable of preventing wear on the end of the screw shaft according to claim 5, characterized in that: An oil outlet pipe is provided on the shell between the first bearing chamber and the second bearing chamber, and an oil inlet pipe is provided on the shell along the spiral axis; the connecting pipe and the extension pipe in the rotary joint form a closed space for connecting the oil outlet cavity and the oil outlet pipe, and the extension pipe extends into the oil inlet pipe and fits tightly with the oil inlet pipe.

7. A preheating machine capable of preventing wear on the end of the screw shaft according to claim 6, characterized in that: The inner wall of the extension tube is provided with an internal thread structure; the wear-resistant sleeve is a steel sleeve, the inner diameter of the wear-resistant sleeve is 140mm, the outer diameter is 160mm, and the barrel length is 240mm; the inner diameter of the graphite bearing is 160mm.

Images