Preheating device for production of benzene hydrogenation device

Abstract

The invention relates to the field of heating reaction furnaces, and discloses a preheating device for benzene hydrogenation unit production, which comprises a main body heat preservation shell, an inner reaction box is arranged in the main body heat preservation shell, a plurality of U-shaped heating pipes are annularly arranged between the inner reaction box and the main body heat preservation shell at equal intervals, and the U-shaped heating pipes are in sliding connection with an in-furnace descaling structure. A water tank is arranged at the upper end of the main body heat preservation shell, the upper end of the water tank is connected with a heat conduction descaling structure, the water tank is communicated with a water pump, the water pump is communicated with the main body heat preservation shell, and the in-furnace descaling structure comprises a first gear which is meshed with second gears which are symmetrically arranged. The preheating device for production of the benzene hydrogenation device effectively solves the problems that an existing benzene hydrogenation water heating reaction furnace is slow in preheating, a heat conduction pipe is large in energy consumption, follow-up hot water recycling, heat preservation and cyclic utilization are poor, meanwhile, scale can be generated after a heating pipe is used for a long time, and the service life of the heating pipe is prolonged. The scale seriously affects heat conduction between water and heat conduction between the heating pipe and the water.

Description

Technical Field

[0001] The invention relates to the technical field of heating reaction furnaces, in particular to a preheating device for production of a benzene hydrogenation device. Background Art

[0002] Patent Publication No. CN115046400A discloses a waste heat utilization device for a benzene hydrogenation heating furnace, comprising a heating furnace body, a feed pipe and a discharge pipe, support legs are installed at the four corners of the bottom end of the heating furnace body, a feed pipe is installed on one side of the support leg, and a first solenoid valve is arranged inside the feed pipe, a discharge pipe is installed on the side of the heating furnace body close to the feed pipe, and a second solenoid valve is arranged inside the discharge pipe, a fuel gas pipe is arranged at the bottom end of the heating furnace body, and a third solenoid valve is arranged on the outer wall of the fuel gas pipe, an outlet pipe is installed at the top end of the heating furnace body, a support frame is arranged on the side of the heating furnace body away from the discharge pipe, and a conveying mechanism for recycling waste heat is arranged on the top of the support frame, the device conveys air after heat exchange to the bottom of the heating furnace body through the waste temperature pipe, accelerates the combustion of the heating furnace body by adding oxygen, and the recycling of waste heat achieves the effect of energy saving and environmental protection.

[0003] However, the existing benzene hydrogenation heating usually uses water heating instead of air heating. In the benzene hydrogenation process, the choice of heating method has an important impact on the reaction efficiency and product quality. Specifically, the benzene hydrogenation reaction needs to be carried out at a certain temperature and pressure, and high pressure and low temperature conditions are usually used to promote the reaction to the right. Water heating can provide stable temperature control and avoid temperature fluctuations and impurity problems that may be caused by air heating. The benzene hydrogenation heating furnace is a key equipment for benzene hydrogenation reaction in the chemical industry. Its main function is to heat benzene and hydrogenation agent to promote the reaction. The optimal temperature range of benzene hydrogenation reaction is 144℃~145℃. At this temperature, the effect of benzene gasification reaction will be significantly improved, the yield of the target product cyclohexene will increase by seven percentage points, and the conversion rate and selectivity can be stably controlled at 45% and 79% or more.

[0004] When using benzene hydrogenation water to heat the reactor, preheating is an important step. However, the existing benzene hydrogenation water heating reactor preheats slowly, the heat pipe consumes a lot of energy, and the subsequent hot water recovery and insulation recycling is poor. At the same time, the long-term use of the heating pipe will produce scale, which will seriously affect the heat conduction between water and between the heating pipe and water.

[0005] Therefore, the present invention provides a preheating device for benzene hydrogenation production to solve the above problems. Summary of the invention

[0006] The problem to be solved by the present invention is that preheating is an important step when using benzene hydrogenation water to heat a reactor. However, the existing benzene hydrogenation water heating reactor preheats slowly, the heat pipe consumes a lot of energy, and the subsequent hot water recovery and insulation recycling is poor. At the same time, the heating pipe will produce scale for a long time, and the scale will seriously affect the heat conduction between water and the heat conduction between the heating pipe and water.

[0007] In order to solve the above technical problems, the technical solution of the present invention is: a preheating device for production of a benzene hydrogenation device, comprising a main insulation shell, an inner reaction box is arranged in the main insulation shell, a plurality of U-shaped heating tubes are arranged in a ring shape and equidistantly between the inner reaction box and the main insulation shell, the U-shaped heating tubes are slidably connected to a descaling structure in the furnace, a water tank is arranged at the upper end of the main insulation shell, the upper end of the water tank is connected to the heat-conducting descaling structure, the water tank is connected to a water pump, and the water pump is connected to the main insulation shell.

[0008] Furthermore, the in-furnace descaling structure includes a first gear, which is meshed with a symmetrically arranged second gear. The bottom of the second gear is connected to one end of a reciprocating screw rod, and the other end of the reciprocating screw rod is rotatably connected to a limiting ring at the lower end of the U-shaped heating tube. The limiting ring is connected to the bottom of the main insulation shell, and the reciprocating screw rod is threadedly connected to the positioning ring.

[0009] Furthermore, the positioning ring is symmetrically provided with through holes, the through holes are slidably connected to the stabilizing rod, the two ends of the stabilizing rod are connected to the inner wall of the main insulation shell and the limiting ring, the limiting ring is provided with scraping holes, and the scraping holes are slidably connected to the U-shaped heating tube.

[0010] Furthermore, the top of the scraping hole of the positioning ring is connected to the bottom of a plurality of high-temperature hoses, and the top of the high-temperature hose is connected to the scraping ring.

[0011] Furthermore, the inner ring of the first gear is connected to one end of a rotating rod, and the rotating rod passes through a water tank, a heat conduction plate, an annular cover and is rotatably connected to the top of the inner wall of the wheel cover. The outer ring at the other end of the rotating rod is fixedly connected to one end of blades arranged equidistantly, and the edge of the blade is in contact with the inner wall of the wheel cover. The wheel cover is connected to one end of a second steam pipe, and the other end of the second steam pipe is connected to one end of a steam valve, and the other end of the steam valve is connected to one end of the first steam pipe, and the other end of the first steam pipe is connected to the upper end of the main insulation shell.

[0012] Furthermore, the heat-conducting and descaling structure includes a heat-conducting plate, the outer ring of the heat-conducting plate is connected to the annular cover, a rotating bearing is arranged in the middle position inside the annular cover, the inner ring of the rotating bearing is connected to the outer ring of the rotating rod, and a plurality of scrapers are arranged in a ring-shaped shape at equal intervals on the outer ring of the rotating bearing, the scrapers are in contact with the bottom of the heat-conducting plate and the inner wall of the annular cover, and the annular cover is provided with an oblique hole, and the oblique hole is connected to the guide pipe.

[0013] Furthermore, one end of the water pump is connected to a three-way valve, and the other two ends of the three-way valve are connected to the water tank and the main insulation shell through pipelines respectively.

[0014] Furthermore, a filter tank is arranged in the pipeline between the main body insulation shell and the three-way valve, the upper end of the filter tank is connected with the main body insulation shell, and the lower end of the filter tank is connected with the three-way valve.

[0015] Furthermore, an opening valve is arranged in the water tank, and the opening valve is connected to the flow equalizing device. The flow equalizing device includes a water collecting shell arranged at the lower end of the cover plate, and the water collecting shell has guide holes equidistantly arranged in a ring shape, and the guide holes are connected to the middle position of the outer circle of the conduit, and the lower end of the conduit corresponds to the upper end of the U-shaped heating tube.

[0016] Furthermore, an arc-shaped opening is provided at the lower end of the conduit, and the arc-shaped opening corresponds to the upper end of the U-shaped heating tube.

[0017] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0018] (1) The three-way valve can switch the heating cycle between the water tank and the heat-conducting and descaling structure and the water in the main insulation shell. At the same time, the heat-conducting and descaling structure can convert solar radiation energy into thermal energy to heat the water, thereby reducing the time for the U-shaped heating tube to heat the water, so as to quickly reach the predetermined temperature of the benzene hydrogenation reaction, thereby improving efficiency and further reducing energy consumption. A large amount of water vapor is formed in the main insulation shell through the contact between water and air. After a large amount of water vapor flows into the bottom of the main insulation shell, the water vapor is pressurized and rises into the first steam pipe. The steam valve is opened, and the blades in the wheel cover are rotated through the first steam pipe, thereby driving the rotating rod, and the rotating rod drives the first gear, so that the motor is no longer needed. The transmission is carried out to further improve the utilization rate of energy. Through the transmission of the first gear, the second gear and the reciprocating screw, the rotation of the reciprocating screw can cause the positioning ring to move up and down, and the high-temperature hose on the positioning ring rises and falls, thereby driving the scraper ring to rise and fall to scrape the scale on the outer wall of the U-shaped heating tube. At the same time, the bending part of the U-shaped heating tube will pass through the bending of the high-temperature hose, thereby being scraped by the scraper ring, so as to more comprehensively scrape the scale on the surface of the U-shaped heating tube, so that the thermal conductivity of the U-shaped heating tube will not decrease with the increase of scale, and the scale cleaned from the outer wall of the U-shaped heating tube enters the filter tank for filtration, so that the personnel can complete the removal of scale by regularly cleaning the filter tank to avoid the scale affecting the heat conduction between water.

[0019] (2) Water can be pumped out of the main insulation shell through the water pump. At the same time, the scale cleaned off the outer wall of the U heating tube enters the filter tank for filtration, thereby pumping out water without scale into the guide pipe. The water in the guide pipe is drained through the oblique holes to cause the scraper to rotate to clean the scale in the heat transfer plate and the annular cover, ensuring the thermal conductivity of the heat transfer plate. Finally, it flows back into the water tank through the through hole connected to the water tank. At the same time, after the water in the main insulation shell is pumped out, the three-way valve switches the water pump to connect with the water tank, ensuring that the heat transfer plate circulates to heat and insulate the water in the water tank.

[0020] (3) The water is heated by the heat conduction plate and enters the water tank. The valve is opened to introduce the water in the water tank into the water collecting shell. As the water is injected, the water level gradually rises above the conduit. Through the conduit, the water evenly enters the arc-shaped opening at the lower end of each conduit and flows into the upper end of the U-shaped heating tube 7. The water is then heated along the U-shaped heating tube, which makes the water temperature rise faster, thereby improving the efficiency of the benzene hydrogenation reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0022] Figure 2 It is a schematic diagram of the structure inside the main insulation shell of the present invention;

[0023] Figure 3 A top view of the present invention;

[0024] Figure 4 for Figure 2 Enlarged view of point A in the middle;

[0025] Figure 5 It is a structural schematic diagram of the descaling structure in the furnace of the present invention;

[0026] Figure 6 It is a schematic diagram of the structure of the first gear and the second gear in the present invention;

[0027] Figure 7 A schematic diagram of the bending of the high temperature hose structure of the present invention;

[0028] Figure 8 It is a schematic diagram of the structure of the positioning ring in the present invention;

[0029] Fig. 9 It is a schematic diagram of the bottom structure of the water collecting shell in the present invention;

[0030] Fig.10 It is a schematic diagram of the structure of the water collecting shell and the cover plate in the present invention;

[0031] Fig.11 for Fig. 9 Enlarged view of point B in the middle;

[0032] Fig.12It is a structural schematic diagram of the heat-conducting and descaling structure in the present invention.

[0033] In the figure: 1-main body insulation shell, 11-inner reaction box, 2-water tank, 21-opening valve, 3-heat conduction and descaling structure, 31-heat conduction plate, 32-annular cover, 33-scraper, 34-rotating bearing, 35-oblique hole, 4-scaling structure in the furnace, 41-first steam pipe, 42-steam valve, 43-second steam pipe, 44-rotating rod, 441-wheel cover, 45-first gear, 46-second gear, 47-reciprocating screw rod, 48-positioning ring, 481-high temperature hose, 482-scraper ring, 49-stabilizing rod, 5-water pump, 51-flow guide pipe, 6-three-way valve, 7-U-shaped heating pipe, 71-limiting ring, 8-uniform flow device, 81-cover plate, 82-water collecting shell, 83-conduit, 831-arc mouth, 9-filter tank. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0035] Unless otherwise defined, the technical terms or scientific terms used in the present disclosure should be understood by people with ordinary skills in the field to which the present disclosure belongs. "Include" or "comprise" and other similar words used in the present disclosure mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and other similar words are not limited to physical or mechanical connections, but may also include electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0036] like Figures 1 to 12As shown, a preheating device for benzene hydrogenation production provided by the present invention comprises a main body insulation shell 1, an inner reaction box 11 is arranged in the main body insulation shell 1, a plurality of U-shaped heating tubes 7 are arranged in an annular manner and equidistantly between the inner reaction box 11 and the main body insulation shell 1, the U-shaped heating tubes 7 are slidably connected to the descaling structure 4 in the furnace, a water tank 2 is arranged at the upper end of the main body insulation shell 1, the water tank 2 is annular, the upper end of the water tank 2 is connected to the heat-conducting descaling structure 3, the water tank 2 is connected to the water pump 5, the water pump 5 is connected to the main body insulation shell 1, and one end of the water pump 5 is connected to the heat-conducting descaling structure 3. It is connected to the three-way valve 6, and the other two ends of the three-way valve 6 are connected to the water tank 2 and the main insulation shell 1 through pipelines. The three-way valve 6 can switch the heating cycle between the water tank and the heat-conducting and descaling structure 3 and the water in the main insulation shell 1. At the same time, the heat-conducting and descaling structure 3 can convert solar radiation energy into thermal energy to heat the water, thereby reducing the time for the U-shaped heating tube 7 to heat the water, so as to quickly reach the predetermined temperature of the benzene hydrogenation reaction, thereby improving efficiency and further reducing energy consumption.

[0037] The in-furnace descaling structure 4 includes a first gear 45, which is meshed with a symmetrically arranged second gear 46. The bottom of the second gear 46 is connected to one end of a reciprocating screw 47, and the other end of the reciprocating screw 47 is rotatably connected to a limiting ring 71 at the lower end of the U-shaped heating tube 7. The limiting ring 71 is connected to the bottom of the main insulation shell 1, and the reciprocating screw 47 is threadedly connected to a positioning ring 48. Through the transmission of the first gear 45, the second gear 46 and the reciprocating screw 47, the rotation of the reciprocating screw 47 can cause the positioning ring 48 to move up and down, and finally the outer wall of the U-shaped heating tube 7 is scraped off the scale.

[0038] The positioning ring 48 is symmetrically provided with through holes, which are slidably connected to the stabilizing rod 49. The two ends of the stabilizing rod 49 are connected to the inner wall of the main insulation shell 1 and the limiting ring 71. The limiting ring 71 has a scraping hole, which is slidably connected to the U-shaped heating tube 7. The stability of the upward and downward movement of the positioning ring 48 can be further ensured by the stabilizing rod 49.

[0039] The top of the scraping hole of the positioning ring 48 is connected to the bottom of multiple high-temperature hoses 481, and the top of the high-temperature hoses 481 is connected to the scraping ring 482. The high-temperature hoses 481 on the positioning ring 48 rise and fall, thereby driving the scraping ring 482 to rise and fall, thereby scraping off the scale on the outer wall of the U-shaped heating tube 7. At the same time, the curved part of the U-shaped heating tube 7 will pass through the bending of the high-temperature hose 481, and thus be scraped off by the scraping ring 482, so that the scale on the surface of the U-shaped heating tube 7 can be scraped off in a more curved manner, so that the thermal conductivity of the U-shaped heating tube 7 will not decrease with the increase of scale.

[0040] The inner ring of the first gear 45 is connected to one end of the rotating rod 44, and the rotating rod 44 passes through the water tank 2, the heat conducting plate 31, the annular cover 32 and is rotatably connected to the top of the inner wall of the wheel cover 441. The outer ring of the other end of the rotating rod 44 is fixedly connected to one end of the blades arranged equidistantly, and the edge of the blade contacts the inner wall of the wheel cover 441. The wheel cover 441 is connected to one end of the second steam pipe 43, and the other end of the second steam pipe 43 is connected to one end of the steam valve 42. The other end of the steam valve 42 is connected to one end of the first steam pipe 41, and the other end of the first steam pipe 41 is connected to the upper end of the main insulation shell 1. Through the contact between water and air, a large amount of water vapor is formed in the main insulation shell 1. After the water flows into the bottom of the main insulation shell 1, the water vapor is pressurized and rises into the first steam pipe 41. The steam valve 42 is opened, and the blades in the wheel cover 441 are rotated through the first steam pipe 41, thereby driving the rotating rod 44, and the rotating rod 44 drives the first gear 45.

[0041] The heat conduction and descaling structure 3 includes a heat conduction plate 31, the outer ring of the heat conduction plate 31 is connected to the annular cover 32, a rotating bearing 34 is arranged in the middle position inside the annular cover 32, the inner ring of the rotating bearing 34 is connected to the outer ring of the rotating rod 44, and the outer ring of the rotating bearing 34 is annularly arranged with a plurality of scrapers 33 at equal intervals, the scrapers 33 are in contact with the bottom of the heat conduction plate 31 and the inner wall of the annular cover 32, the annular cover 32 is provided with an oblique hole 35, and the oblique hole 35 is connected to the guide pipe 51. After the reaction heating of benzene and hydrogen in the inner reaction box 11 is completed, the steam valve 42 is opened, and the three-way valve 6 switches the water pump 5 to be connected to the main insulation shell 1, and the water pump 5 can The water can be pumped out of the main insulation shell 1, and the scale cleaned off the outer wall of the U heating tube 7 enters the filter tank 9 for filtration, so that the water without scale is pumped out and enters the guide pipe 51. The water in the guide pipe 51 is drained through the oblique hole 35 to cause the scraper 33 to rotate to clean the scale in the heat conduction plate 31 and the annular cover 32, so as to ensure the thermal conductivity of the heat conduction plate 31, and finally flows back into the water tank 2 through the through hole connected to the water tank 2. At the same time, after the water in the main insulation shell 1 is pumped out, the three-way valve 6 switches the water pump 5 to be connected with the water tank 2, so that the heat conduction plate 31 circulates the water in the water tank 2 for circulation, heating and insulation.

[0042] A filter tank 9 is arranged in the pipeline between the main insulation shell 1 and the three-way valve 6. The upper end of the filter tank 9 is connected to the main insulation shell 1, and the lower end of the filter tank 9 is connected to the three-way valve 6. The scale cleaned from the outer wall of the U heating tube 7 enters the filter tank 9 for filtration, so that personnel can complete the removal of scale by regularly cleaning the filter tank 9 to prevent the scale from affecting the heat conduction between water.

[0043] An opening valve 21 is arranged in the water tank 2, and the opening valve 21 is connected with the uniform flow device 8. The uniform flow device 8 includes a water collecting shell 82 arranged at the lower end of the cover plate 81, and the water collecting shell 82 is provided with guide holes at equal intervals in a ring shape, and the guide holes are connected to the middle position of the outer circle of the conduit 83. The lower end of the conduit 83 corresponds to the upper end of the U-shaped heating tube 7, and the lower end of the conduit 83 is provided with an arc-shaped opening 831, and the arc-shaped opening 831 corresponds to the upper end of the U-shaped heating tube 7. The water is heated up through the heat conducting plate 31 and enters the water tank 2. The opening valve 21 is opened to introduce the water in the water tank 2 into the water collecting shell 82. As the water injection level gradually rises above the conduit 83, the water evenly enters the arc-shaped opening 831 at the lower end of each conduit 83 through the conduit 83 and flows into the upper end of the U-shaped heating tube 7. The water is then heated along the U-shaped heating tube 7, so that the water is heated more quickly, thereby improving the efficiency of the benzene hydrogenation reaction.

[0044] The working principle and use process of the present invention are as follows: water is heated up through the heat conducting plate 31 and enters the water tank 2. The valve 21 is opened to introduce the water in the water tank 2 into the water collecting shell 82. As the water is injected, it gradually rises above the conduit 83. Through the conduit 83, the water evenly enters the arc-shaped opening 831 at the lower end of each conduit 83 and flows into the upper end of the U-shaped heating tube 7. The water is then heated along the U-shaped heating tube 7, so that the water is heated up more quickly. A large amount of water vapor is formed in the main heat-insulating shell 1 through the contact between water and air. After the water flows into the bottom of the main heat-insulating shell 1, the water vapor is pressurized and rises into the first steam pipe 41 and the steam valve 42. Open, through the first steam pipe 41, the blades in the wheel cover 441 rotate, thereby driving the rotating rod 44, and the rotating rod 44 drives the first gear 45, the second gear 46 and the reciprocating screw 47. The rotation of the reciprocating screw 47 causes the positioning ring 48 to move up and down, and the high-temperature hose 481 on the positioning ring 48 rises, thereby driving the scraper ring 482 to rise, thereby scraping the scale on the outer wall of the U-shaped heating tube 7. At the same time, the curved part of the U-shaped heating tube 7 will pass through the bending of the high-temperature hose 481, thereby being scraped by the scraper ring 482. When the water in the main insulation shell 1 is full, the steam valve 42 is closed and the opening valve 21 is closed.

[0045] After the reaction heating of benzene and hydrogen in the internal reaction box 11 is completed, the steam valve 42 is opened, and the three-way valve 6 switches the water pump 5 to be connected with the main insulation shell 1. Water can be pumped out of the main insulation shell 1 through the water pump 5. At the same time, the scale cleaned off the outer wall of the heating tube enters the filter tank 9 for filtration, so that the water without scale is pumped out and enters the guide pipe 51. The water in the guide pipe 51 is drained through the oblique hole 35 to cause the scraper 33 to rotate to clean the scale in the heat conduction plate 31 and the annular cover 32, thereby ensuring the thermal conductivity of the heat conduction plate 31, and finally flows back into the water tank 2 through the through hole connected to the water tank 2. At the same time, after the water in the main insulation shell 1 is pumped out, the three-way valve 6 switches the water pump 5 to be connected with the water tank 2, so that the heat conduction plate 31 circulates the water in the water tank 2 for circulation, heating and insulation.

[0046] The above embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims

1. A preheating device for benzene hydrogenation production, comprising a main body insulation shell (1), characterized in that: An internal reaction box (11) is arranged inside the main body insulation shell (1); a plurality of U-shaped heating tubes (7) are arranged in a circular shape and at equal intervals between the internal reaction box (11) and the main body insulation shell (1); the U-shaped heating tubes (7) are slidably connected to the descaling structure (4) in the furnace; a water tank (2) is arranged at the upper end of the main body insulation shell (1); the upper end of the water tank (2) is connected to the heat-conducting descaling structure (3); the water tank (2) is connected to a water pump (5); and the water pump (5) is connected to the main body insulation shell (1).

2. A preheating device for production of benzene hydrogenation device according to claim 1, characterized in that: The in-furnace descaling structure (4) comprises a first gear (45), the first gear (45) meshing with a symmetrically arranged second gear (46), the bottom of the second gear (46) being connected to one end of a reciprocating screw (47), the other end of the reciprocating screw (47) being rotatably connected to a limiting ring (71) at the lower end of a U-shaped heating tube (7), the limiting ring (71) being connected to the bottom of the main heat-insulating shell (1), and the reciprocating screw (47) being threadedly connected to a positioning ring (48).

3. A preheating device for production of benzene hydrogenation device according to claim 2, characterized in that: The positioning ring (48) is symmetrically provided with perforations, the perforations are slidably connected to the stabilizing rod (49), the two ends of the stabilizing rod (49) are connected to the inner wall of the main insulation shell (1) and the limiting ring (71), the limiting ring (71) is provided with scraping holes, and the scraping holes are slidably connected to the U-shaped heating tube (7).

4. A preheating device for production of benzene hydrogenation device according to claim 3, characterized in that: The top of the scraping hole of the positioning ring (48) is connected to the bottom of a plurality of high-temperature hoses (481), and the top of the high-temperature hoses (481) is connected to the scraping ring (482).

5. A preheating device for benzene hydrogenation production according to claim 2, characterized in that: The inner ring of the first gear (45) is connected to one end of the rotating rod (44), and the rotating rod (44) passes through the water tank (2), the heat conduction plate (31), the annular cover (32) and is rotatably connected to the top of the inner wall of the wheel cover (441). The outer ring of the other end of the rotating rod (44) is fixedly connected to one end of blades arranged at equal intervals, and the edge of the blade is in contact with the inner wall of the wheel cover (441). The wheel cover (441) is connected to one end of the second steam pipe (43), and the other end of the second steam pipe (43) is connected to one end of the steam valve (42). The other end of the steam valve (42) is connected to one end of the first steam pipe (41), and the other end of the first steam pipe (41) is connected to the upper end of the main body insulation shell (1).

6. A preheating device for production of benzene hydrogenation device according to claim 1, characterized in that: The heat conduction and descaling structure (3) comprises a heat conduction plate (31), the outer ring of the heat conduction plate (31) is connected to an annular cover (32), a rotating bearing (34) is arranged at a middle position inside the annular cover (32), the inner ring of the rotating bearing (34) is connected to the outer ring of a rotating rod (44), a plurality of scrapers (33) are arranged in an annular shape and equidistantly on the outer ring of the rotating bearing (34), the scrapers (33) are in contact with the bottom of the heat conduction plate (31) and the inner wall of the annular cover (32), the annular cover (32) is provided with an oblique hole (35), and the oblique hole (35) is connected to a flow guide pipe (51).

7. A preheating device for production of benzene hydrogenation device according to claim 1, characterized in that: One end of the water pump (5) is connected to a three-way valve (6), and the other two ends of the three-way valve (6) are connected to the water tank (2) and the main body insulation shell (1) through pipelines.

8. A preheating device for production of benzene hydrogenation device according to claim 3, characterized in that: A filter tank (9) is provided in the pipeline between the main body insulation shell (1) and the three-way valve (6); the upper end of the filter tank (9) is connected to the main body insulation shell (1), and the lower end of the filter tank (9) is connected to the three-way valve (6).

9. A preheating device for production of benzene hydrogenation device according to claim 1, characterized in that: An opening valve (21) is arranged in the water tank (2), and the opening valve (21) is connected to the flow equalizing device (8). The flow equalizing device (8) comprises a water collecting shell (82) arranged at the lower end of the cover plate (81), and the water collecting shell (82) is provided with guide holes equidistantly arranged in a ring shape, and the guide holes are connected to the middle position of the outer circle of the guide tube (83), and the lower end of the guide tube (83) corresponds to the upper end of the U-shaped heating tube (7).

10. A preheating device for benzene hydrogenation production according to claim 9, characterized in that: The lower end of the conduit (83) is provided with an arc-shaped opening (831), and the arc-shaped opening (831) corresponds to the upper end of the U-shaped heating tube (7).

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