Methanol external cracking device and method for salt bath quenching furnace

Abstract

The invention relates to the technical field of gas generation devices, in particular to a methanol external cracking device and method for a salt bath quenching furnace. The methanol external cracking device for the salt bath quenching furnace comprises a reaction cylinder, a gas guide pipe, a catalysis cylinder and a heat exchange cylinder, the reaction cylinder is fixedly arranged, the reaction cylinder is provided with an end cover, an upper cavity and a lower cavity are sequentially formed in the reaction cylinder in the vertical direction, the gas guide pipe is arranged in the upper cavity, the gas guide pipe can communicate with the upper cavity and the lower cavity, and vaporized methanol enters the upper cavity from the lower cavity; the multiple catalytic cylinders are sequentially arranged on the gas guide pipe in a sleeving mode from inside to outside, and every two adjacent catalytic cylinders are connected in a sliding mode. After the methanol in the reaction cylinder is cracked for a period of time, the carbon deposition amount on the surface of the catalyst on the filter screen of the catalytic cylinder closest to the gas guide pipe is large, at the moment, the end cover can be opened to draw out the catalytic cylinder, and a new catalytic cylinder is arranged on the periphery of the residual catalytic cylinder on the peripheral surface of the gas guide pipe in a sleeving manner, so that the replacement is convenient, and the utilization rate of the catalytic cylinder can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of gas generating devices, and in particular to a methanol off-furnace cracking device and method for a salt bath quenching furnace. Background Art

[0002] In the field of modern industrial manufacturing, especially in the metal heat treatment process, salt bath quenching furnace plays a pivotal role. With the increasing attention paid to environmental protection and the profound adjustment of energy structure, the application of hydrogen as a fuel in salt bath quenching furnace has gradually come into people's view.

[0003] Although the traditional method of hydrogen production is mature, it is constrained by cost and environmental protection policies, which has led to a decline in the economic benefits of companies that rely on this method and restricted project development.

[0004] Methanol is a basic chemical raw material with a wide range of sources and is easy to store and transport. As a major methanol producer, my country has sufficient methanol supply. Methanol cracking hydrogen production technology has emerged as the times require. It uses methanol to produce hydrogen through cracking and conversion reactions under the action of catalysts.

[0005] After long-term operation, the activity of the catalyst inside the existing reactor will gradually decrease, and it needs to be replaced regularly to maintain an efficient cracking reaction. However, the existing reactor structure design makes the operation of replacing the catalyst extremely complicated, and often requires the disassembly of a large number of auxiliary components. At the same time, the existing reactor structure often replaces the entire catalyst when replacing the catalyst, resulting in a waste of catalyst that has not completely lost its activity. If a partial replacement is used, it is easy to cause an incomplete cracking reaction. Summary of the invention

[0006] Based on this, it is necessary to provide a methanol off-furnace cracking device and method for a salt bath quenching furnace to address the problems of inconvenient catalyst replacement in the current reactor and incomplete cracking reaction caused by partial catalyst replacement.

[0007] The above purpose is achieved through the following technical solutions: A methanol off-furnace cracking device for a salt bath quenching furnace comprises a vaporizer, a superheater and a reactor. The vaporizer is used to vaporize methanol, the superheater is used to heat the vaporized methanol, and the heated methanol enters the reactor. The reactor comprises a reaction tube, an air duct, a catalytic tube and a heat exchange tube. The reaction tube is fixedly arranged, and the reaction tube is provided with an end cover. An upper cavity and a lower cavity are sequentially arranged in the vertical direction in the reaction tube. The air duct is arranged in the upper cavity, and one end of the air duct is connected with the lower cavity, and the other end of the air duct extends toward the end cover. A plurality of air outlet holes for connecting the upper cavity and the inside of the air duct are provided on the circumference of the air duct, and the vaporized methanol enters the upper cavity from the lower cavity. A plurality of catalytic tubes are provided, and the plurality of catalytic tubes are sequentially sleeved on the air duct from the inside to the outside, and two adjacent catalytic tubes are slidably connected. The heat exchange tube is arranged on the circumference of the air duct, and the heat exchange tube is located between the catalytic tube and the air duct, and is used to make the methanol in the air duct reach a preset temperature.

[0008] Preferably, the catalytic tube includes a support tube and a filter screen. The peripheral surface of the support tube is wavy and elastic. Two support tubes are provided. The two support tubes are sleeved on the air duct and arranged along the axial direction of the air duct. The filter screen is provided between the two support tubes and the filter screens are respectively connected to the end faces of the two support tubes. The filter screen extends around the end face of the support tube along the circumference of the support tube and is connected end to end. A catalyst is attached to the filter screen.

[0009] Preferably, the catalytic tube also includes multiple struts and multiple vertical rods, the struts are elastic and each strut is connected end to end, the shape of the struts is consistent with the shape of the support tube, the multiple struts are located between the two support tubes, and the multiple struts are evenly arranged along the axial direction of the guide tube; the two ends of each vertical rod are respectively fixedly connected to the two support tubes, and each vertical rod extends along the axial direction of the guide tube, the multiple vertical rods are evenly arranged around the circumferential direction of the top ring, and each vertical rod is connected to multiple struts.

[0010] Preferably, the thickness of the filter screen in the radial direction of the guide tube is smaller than the thickness of the support tube, the vertical rod and the strut in the radial direction of the guide tube, and the support tube and the vertical rod in two adjacent catalytic tubes are slidably connected.

[0011] Preferably, a plurality of fixed plates are provided in the reaction cylinder, the plurality of fixed plates are arranged in the upper cavity and arranged in the vertical direction, and each fixed plate is provided with an air hole and a conical hole, a plurality of air holes are provided, and the plurality of air holes penetrate the fixed plate in the vertical direction and are evenly distributed on the fixed plate; the conical hole penetrates the fixed plate along the axial direction of the air guide tube, the air guide tube is arranged in the conical hole, the conical hole includes a large mouth end and a small mouth end, the small mouth end of the conical hole is located below the large mouth end, and the small mouth diameter of the conical hole is larger than the diameter of the air guide tube.

[0012] Preferably, a slope is provided on a side of the support tube away from the filter screen, and the slope gradually moves away from the filter screen from a side close to the air duct to a side away from the air duct.

[0013] Preferably, a partition is provided in the reaction cylinder, the partition is located between the upper chamber and the lower chamber, one end of the air guide tube passes through the partition and is fixedly connected to the partition; the heat exchange cylinder comprises an air inlet cylinder, an air outlet cylinder, a first tube, a second tube and a connecting cover, the air inlet cylinder and the air outlet cylinder are sleeved on the air guide tube, and the air inlet cylinder and the air outlet cylinder are both located in the lower chamber; there are multiple first tubes and second tubes, one end of the multiple first tubes is fixedly installed on the air inlet cylinder and is connected to the air inlet cylinder, one end of the multiple second tubes is fixedly installed on the air outlet cylinder and is connected to the air outlet cylinder, the multiple first tubes and the multiple second tubes are evenly and alternately arranged around the air guide tube, the multiple first tubes and the multiple second tubes are spirally wound on the air guide tube and extend along the axial direction of the air guide tube, and a spacing is provided between adjacent first tubes and second tubes; the connecting cover is arranged on the end of the air guide tube away from the lower chamber, the ends of the multiple first tubes away from the air inlet cylinder and the ends of the multiple second tubes away from the air outlet cylinder are connected to the connecting cover, and the multiple first tubes and the multiple second tubes are connected through the connecting cover.

[0014] Preferably, a baffle and an air outlet are provided on the end cover, one branch tube in the catalytic tube abuts against the partition, and another branch tube in the catalytic tube abuts against the baffle, the air outlet is located on the side of the baffle away from the catalytic tube, and a plurality of through holes are opened on the baffle; an air inlet is provided on the reaction tube, and the air inlet is connected to the lower cavity for introducing methanol in the superheater into the reaction tube.

[0015] Preferably, an air guide tube, a plurality of catalytic cylinders and a heat exchange cylinder form a catalytic group, a plurality of catalytic groups are arranged in the reaction cylinder, and the plurality of catalytic groups are evenly arranged in the reaction cylinder.

[0016] The present invention also provides a method for cracking methanol outside a salt bath quenching furnace, comprising the following steps: S1, methanol is vaporized after passing through the vaporizer.

[0017] S2, the vaporized methanol is heated by a superheater.

[0018] S3, the vaporized methanol after heating enters the lower chamber of the reactor, and then the vaporized methanol contacts the heat exchange cylinder through the air guide pipe, and the heat exchange cylinder supplements the temperature of the vaporized methanol to a preset temperature.

[0019] S4, the vaporized methanol leaving the gas duct passes through the catalytic cylinder to undergo cracking reaction.

[0020] The beneficial effects of the present invention are as follows: the design of multiple catalytic cartridge sleeves increases the contact time between methanol and the catalyst, and after the methanol is discharged from the air duct, the methanol that has not been able to react with the catalyst in time can react with the catalyst that is subsequently contacted; after the methanol in the reaction cartridge is cracked for a period of time, the amount of carbon deposits on the catalyst surface on the filter screen of the catalytic cartridge closest to the air duct is relatively large, and at this time the end cover can be opened to pull out the catalytic cartridge, and a new catalytic cartridge can be sleeved on the periphery of the remaining catalytic cartridge on the outer peripheral surface of the air duct, which is convenient for replacement and can also improve the utilization rate of the catalytic cartridge, and the carbon deposit content on the surface of the catalyst in the catalytic cartridge far away from the air duct is relatively small, which can enable the methanol entering the upper chamber to be fully cracked; the heat exchange cartridge is provided, so that the temperature of the methanol that is about to contact the filter screen can be maintained at a preset value, thereby improving the cracking efficiency of the methanol. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic structural diagram of a methanol off-furnace cracking device for a salt bath quenching furnace provided in an embodiment of the present invention; Figure 2 A cross-sectional view of a methanol off-furnace cracking device for a salt bath quenching furnace provided in an embodiment of the present invention; Figure 3 for Figure 2 The enlarged view of point B in the middle; Figure 4 for Figure 2 The enlarged view of point A in the middle; Figure 5 A schematic structural diagram of a heat exchange cylinder of a methanol off-furnace cracking device for a salt bath quenching furnace provided in an embodiment of the present invention; Figure 6 A schematic structural diagram of a catalytic cartridge of a methanol off-furnace cracking device for a salt bath quenching furnace provided in an embodiment of the present invention.

[0022] in: 100, reaction tube; 101, air guide tube; 102, end cover; 103, upper chamber; 104, lower chamber; 105, baffle; 106, air outlet; 107, air inlet; 108, partition; 110, support tube; 111, filter screen; 112, support bar; 113, vertical rod; 114, fixing plate; 120, air inlet tube; 121, air outlet tube; 122, first tube; 123, second tube; 124, connecting cover. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in the present invention, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0025] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0026] like Figures 1 to 6 As shown, an embodiment of the present invention provides a methanol off-furnace cracking device for a salt bath quenching furnace, comprising a vaporizer, a superheater and a reactor, wherein the vaporizer is used to vaporize methanol, the superheater is used to heat the vaporized methanol, and the heated methanol enters the reactor, the reactor comprises a reaction cylinder 100, an air guide pipe 101, a catalytic cylinder and a heat exchange cylinder, the reaction cylinder 100 is fixedly arranged, the reaction cylinder 100 is provided with an end cover 102, an upper chamber 103 and a lower chamber 104 are sequentially arranged in the vertical direction in the reaction cylinder 100, the air guide pipe 101 is arranged in the upper chamber 103, and the air guide pipe 101 is arranged in the upper chamber 103, and the air guide pipe 101 is arranged in the upper chamber 103. One end of the air duct 101 is connected with the lower cavity 104, and the other end of the air duct 101 extends to the end cover 102. A plurality of air outlets for connecting the upper cavity 103 and the inside of the air duct 101 are provided on the circumference of the air duct 101, and the vaporized methanol enters the upper cavity 103 from the lower cavity 104; a plurality of catalytic cylinders are provided, and the plurality of catalytic cylinders are sequentially sleeved on the air duct 101 from the inside to the outside, and two adjacent catalytic cylinders are slidably connected; a heat exchange cylinder is provided on the circumference of the air duct 101, and the heat exchange cylinder is located between the catalytic cylinder and the air duct 101, and is used to make the methanol in the air duct 101 reach a preset temperature.

[0027] The design of multiple catalytic cartridges increases the contact time between methanol and the catalyst. After methanol is discharged from the air duct 101, the methanol that has not reacted with the catalyst in time can react with the catalyst that comes into contact with it later. After the methanol in the reaction cartridge 100 has been cracked for a period of time, the amount of carbon deposits on the catalyst surface on the filter screen 111 of the catalytic cartridge closest to the air duct 101 is relatively large. At this time, the end cover 102 can be opened to pull out the catalytic cartridge, and a new catalytic cartridge can be sleeved on the periphery of the remaining catalytic cartridges on the outer peripheral surface of the air duct 101. This facilitates replacement and improves the utilization rate of the catalytic cartridge. The carbon deposit content on the surface of the catalyst in the catalytic cartridge far away from the air duct 101 is relatively small, which can enable the methanol entering the upper chamber 103 to be fully cracked. The heat exchange cartridge is provided to maintain the temperature of the methanol that is about to contact the filter screen 111 at a preset value, thereby improving the cracking efficiency of the methanol.

[0028] In this embodiment, the catalytic cylinder includes a support cylinder 110 and a filter screen 111. The peripheral surface of the support cylinder 110 is wavy and elastic. Two support cylinders 110 are provided. The two support cylinders 110 are sleeved on the air duct 101 and arranged along the axial direction of the air duct 101. The filter screen 111 is arranged between the two support cylinders 110, and the filter screen 111 is respectively connected to the end surfaces of the two support cylinders 110. The filter screen 111 extends circumferentially around the support cylinder 110 on the end surface of the support cylinder 110 and is connected end to end. A catalyst is attached to the filter screen 111. By cooperating with the support tube 110 and the filter screen 111, the peripheral surfaces of the support tube 110 and the filter screen 111 are uneven. After the support tube 110 and the filter screen 111 are subjected to the radial pressure of the air duct 101, the support tube 110 and the filter screen 111 can shrink or expand along the radial direction of the air duct 101; at the same time, there will be pressure between the multiple layers of support tubes 110, and the support tube 110 located in the innermost layer is subjected to the greatest extrusion pressure, which can drive the corresponding filter screen 111 to shrink; on the contrary, the support tube 110 located in the outermost layer is subjected to the greatest expansion force, which can drive the corresponding filter screen 111 to expand accordingly.

[0029] In the present embodiment, the catalytic tube further comprises a plurality of struts 112 and a plurality of vertical rods 113, the struts 112 are all elastic and each strut 112 is connected end to end, the shape of the struts 112 is consistent with the shape of the support tube 110, the plurality of struts 112 are located between the two support tubes 110, and the plurality of struts 112 are evenly arranged along the axial direction of the guide tube; the two ends of each vertical rod 113 are respectively fixedly connected to the two support tubes 110, and each vertical rod 113 extends along the axial direction of the guide tube, the plurality of vertical rods 113 are evenly arranged around the circumferential direction of the top ring, and among two adjacent vertical rods 113, one vertical rod 113 is connected to two wave crests in the two support tubes 110, and the other vertical rod 113 is connected to two wave troughs in the two support tubes 110, each vertical rod 113 is connected to the plurality of struts 112, and the vertical rod 113 connected to the wave crest of the support tube 110 is also connected to a wave crest of the plurality of struts 112. The plurality of struts 112 and the plurality of vertical rods 113 can increase the overall strength of the catalytic tube.

[0030] In this embodiment, the thickness of the filter screen 111 in the radial direction of the guide tube is smaller than the thickness of the support tube 110, the vertical rod 113 and the strut 112 in the radial direction of the guide tube. The support tube 110 and the vertical rod 113 in two adjacent catalytic tubes are slidably connected. When the two adjacent catalytic tubes slide against each other, the filter screen 111 in one catalytic tube will not contact the other catalytic tube. When the catalytic tube is inserted or pulled out, the carbon deposits on the filter screen 111 are not easy to fall off.

[0031] In this embodiment, a plurality of fixing plates 114 are provided in the reaction cylinder 100. The plurality of fixing plates 114 are arranged in the upper chamber 103 and arranged in the vertical direction. A vent hole and a cone hole are provided on each fixing plate 114. A plurality of vent holes are provided. The plurality of vent holes penetrate the fixing plate 114 in the vertical direction and are evenly distributed on the fixing plate 114. The gas in the upper chamber 103 can pass through the fixing plate 114 through the vent holes. The cone hole penetrates the fixing plate 114 in the axial direction of the air guide tube 101. The air duct 101 is arranged in a conical hole, the diameter of the conical hole is larger than the diameter of the air duct 101, the conical hole includes a large mouth end and a small mouth end, the small mouth end of the conical hole is located below the large mouth end, when multiple support tubes 110 are sleeved on the air duct 101, the diameter of the outermost catalytic tube that is continuously wrapped will become larger, and the catalytic tube will squeeze the catalytic tube inside it under the guidance of the conical surface of the conical hole, so that the multiple catalytic tubes are contracted, and at the same time, the fixing plate 114 can also support the catalytic tube.

[0032] In the present embodiment, a slope is provided on the side of the support tube 110 away from the filter screen 111, and the slope gradually moves away from the filter screen 111 from the side close to the air duct 101 to the side away from the air duct 101. When two adjacent catalytic tubes are sleeved, the support tube 110 in the catalytic tube of the outer circle will slide in contact with the support tube 110 in the catalytic tube of the inner circle through its own slope, and the support tube 110 in the catalytic tube of the outer circle will be expanded, and at the same time, the support tube 110 in the catalytic tube of the inner circle will also be subjected to a contraction force, which is convenient for the installation of the catalytic tube.

[0033] In this embodiment, a partition 108 is provided in the reaction cylinder 100, and the partition 108 is located between the upper chamber 103 and the lower chamber 104. One end of the air guide tube 101 passes through the partition 108 and is fixedly connected to the partition 108. The heat exchange cylinder includes an air inlet cylinder 120, an air outlet cylinder 121, a first tube 122, a second tube 123 and a connecting cover 124. The air inlet cylinder 120 and the air outlet cylinder 121 are sleeved on the air guide tube 101, and the air inlet cylinder 120 and the air outlet cylinder 121 are both Located in the lower cavity 104; a plurality of first tubes 122 and a plurality of second tubes 123 are provided, one end of the plurality of first tubes 122 is fixedly mounted on the air inlet cylinder 120 and is communicated with the air inlet cylinder 120, one end of the plurality of second tubes 123 is fixedly mounted on the air outlet cylinder 121 and is communicated with the air outlet cylinder 121, the plurality of first tubes 122 and the plurality of second tubes 123 are evenly and alternately arranged around the air guide tube 101, and the plurality of first tubes 122 and the plurality of second tubes 123 are spirally wound The first tube 122 and the second tube 123 are connected to each other through the connecting cover 124, and the connecting cover 124 is connected to the gas pipe 101 through the gas outlet hole and the gap between the first tube 122 and the second tube 123. The connecting cover 124 is provided on the end of the gas pipe 101 away from the lower cavity 104, and the ends of the plurality of first tubes 122 away from the gas inlet cylinder 120 and the ends of the plurality of second tubes 123 away from the gas outlet cylinder 121 are connected to the connecting cover 124, and the plurality of first tubes 122 and the plurality of second tubes 123 are connected through the connecting cover 124. The heat exchange medium is introduced into the heat exchange cylinder, and the heat exchange medium enters the plurality of first tubes 122 from the gas inlet cylinder 120, and then enters the second tube 123 through the connecting cover 124, and finally is discharged through the gas outlet cylinder 121. The first tube 122 and the second tube 123 can make the temperature of the peripheral surface of the gas pipe 101 more uniform and the cracking of methanol more complete.

[0034] In this embodiment, a baffle 105 and an air outlet 106 are provided on the end cover 102, one branch tube 110 in the catalytic tube abuts against the partition 108, and another branch tube 110 in the catalytic tube abuts against the baffle 105, and the methanol discharged from the air duct 101 can only enter the upper chamber 103 through the filter 111 in the catalytic tube; the air outlet 106 is located on the side of the baffle 105 away from the catalytic tube, and the baffle 105 is provided with a plurality of through holes, and the catalytic product can be discharged from the reaction tube 100 through the through holes from the air outlet 106. The reaction tube 100 is provided with an air inlet 107, which is connected to the lower chamber 104 and is used to introduce the methanol in the superheater into the reaction tube 100.

[0035] In this embodiment, an air duct 101, multiple catalytic cylinders and a heat exchange cylinder form a catalytic group. Multiple catalytic groups are arranged in the reaction cylinder 100. The multiple catalytic groups are evenly arranged in the reaction cylinder 100. The multiple catalytic groups participate in the methanol cracking process at the same time, thereby increasing the reaction efficiency.

[0036] The working principle of the methanol off-furnace cracking device for a salt bath quenching furnace provided in the above embodiment is: First, a heat exchange medium is introduced into the first tube 122 through the air inlet 120. After the heat exchange medium flows into the connecting cover 124 in the first tube 122, it will enter the second tube 123 through the connecting cover 124. The heat exchange medium in the first tube 122 and the second tube 123 can keep the air guide tube 101 warm. Then, the vaporized and heated methanol enters the lower chamber 104 of the reaction tube 100 through the air inlet 107, then enters the air guide tube 101, and then passes through the upper chamber 101 of the air guide tube 101. The methanol discharged from the air duct 101 through the air outlet hole can be heated to a preset temperature when passing between the first tube 122 and the second tube 123, and then the methanol will approach the filter 111. After contacting the filter 111, the methanol will react with the catalyst on the filter 111, and the generated product will enter the upper chamber 103; then the generated product will pass through the air holes on the fixing plate 114 to approach the air outlet 106, and finally be discharged from the reaction cylinder 100 from the air outlet 106.

[0037] The methanol concentration of the methanol discharged from the air duct 101 will decrease after contacting the filter 111. The amount of methanol contacted by the multiple catalytic cylinders from the inside to the outside will gradually decrease, and the amount of carbon deposits on the catalyst surface on the filter 111 in the innermost catalytic cylinder will be relatively large. When the amount of carbon deposits on the filter 111 in the innermost catalytic cartridge reaches a certain level, the end cover 102 is opened, and then a branch tube 110 in the innermost catalytic cartridge is pulled, and the branch tube 110 pulls another branch tube 110 to move together through the vertical rod 113, and the filter 111 moves accordingly. After the catalytic cartridge that needs to be replaced is taken out, a new catalytic cartridge needs to be added. The branch tube 110 of the new catalytic cartridge contacts the outermost branch tube 110 sleeved on the air guide pipe 101 through its own inclined surface. The branch tube 110 of the new catalytic cartridge will expand and continue to push the new catalytic cartridge to move along the axial direction of the air guide pipe 101. The new catalytic cartridge is sleeved on the outermost catalytic cartridge of the air guide pipe 101. When the branch tube 110 in the new catalytic cartridge contacts the fixing plate 114, the tapered hole on the fixing plate 114 causes the new catalytic cartridge to shrink, and the vertical rod 113 is slidably connected to the fixing plate 114.

[0038] After one branch tube 110 of the new catalyst tube abuts against the partition plate 108, the end cover 102 is covered, and the baffle plate 105 abuts against the other branch tube 110 of the new catalyst tube, and the replacement process is completed.

[0039] The present invention also provides a method for cracking methanol outside a salt bath quenching furnace, and the method comprises the following steps: S1, methanol is vaporized after passing through the vaporizer; methanol raw material enters the vaporizer and is vaporized in the vaporizer.

[0040] S2, the vaporized methanol is heated by a superheater; the vaporized methanol enters the superheater, and the superheater heats the vaporized methanol.

[0041] S3, the vaporized methanol after heating enters the lower chamber 104 of the reactor, and then the vaporized methanol contacts the heat exchange tube through the air duct 101, and the heat exchange tube replenishes the temperature of the vaporized methanol to a preset temperature; after the methanol enters the lower chamber 104 of the reactor and enters the air duct 101, heat loss is inevitable. After entering the air duct 101, the vaporized methanol will be heated to a preset temperature under the action of the first tube 122 and the second tube 123.

[0042] S4, the vaporized methanol leaving the air duct 101 undergoes a cracking reaction through the catalytic tube; after leaving the air duct 101, the vaporized methanol quickly contacts the catalyst on the filter 111 in the catalytic tube to undergo a cracking reaction, thereby reducing temperature loss and making the reaction more complete.

[0043] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0044] The above-described embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A methanol off-furnace cracking device for a salt bath quenching furnace, comprising: A vaporizer, a superheater and a reactor, wherein the vaporizer is used to vaporize methanol, and the superheater is used to heat the vaporized methanol, and the heated methanol enters the reactor, and is characterized in that: the reactor comprises a reaction tube, an air duct, a catalytic tube and a heat exchange tube, the reaction tube is fixedly arranged, the reaction tube is provided with an end cover, an upper cavity and a lower cavity are sequentially arranged in the vertical direction in the reaction tube, the air duct is arranged in the upper cavity, and one end of the air duct is connected with the lower cavity, and the other end of the air duct extends toward the end cover, a plurality of air outlet holes for connecting the upper cavity and the inside of the air duct are opened on the circumference of the air duct, and the vaporized methanol enters the upper cavity from the lower cavity; a plurality of catalytic tubes are provided, and the plurality of catalytic tubes are sequentially sleeved on the air duct from the inside to the outside, and two adjacent catalytic tubes are slidably connected; a heat exchange tube is arranged on the circumference of the air duct, and the heat exchange tube is located between the catalytic tube and the air duct, and is used to make the methanol in the air duct reach a preset temperature.

2. The methanol off-furnace cracking device for a salt bath quenching furnace according to claim 1, characterized in that: The catalytic cylinder includes a support cylinder and a filter screen. The peripheral surface of the support cylinder is wavy and elastic. Two support cylinders are provided. The two support cylinders are sleeved on the air duct and arranged along the axial direction of the air duct. The filter screen is provided between the two support cylinders and is respectively connected to the end faces of the two support cylinders. The filter screen extends around the support cylinder on the end face of the support cylinder and is connected end to end. A catalyst is attached to the filter screen.

3. The methanol off-furnace cracking device for a salt bath quenching furnace according to claim 2, characterized in that: The catalytic tube also includes a plurality of struts and a plurality of vertical rods. The struts are elastic and each strut is connected end to end. The shape of the struts is consistent with the shape of the support tube. The plurality of struts are located between two support tubes, and the plurality of struts are evenly arranged along the axial direction of the guide tube. The two ends of each vertical rod are respectively fixedly connected to the two support tubes, and each vertical rod extends along the axial direction of the guide tube. The plurality of vertical rods are evenly arranged in the circumferential direction around the top ring, and each vertical rod is connected to the plurality of struts.

4. The methanol off-furnace cracking device for a salt bath quenching furnace according to claim 3, characterized in that: The thickness of the filter screen in the radial direction of the guide tube is smaller than the thickness of the support tube, the vertical rod and the stay in the radial direction of the guide tube, and the support tube and the vertical rod in two adjacent catalytic tubes are slidably connected.

5. The methanol off-furnace cracking device for a salt bath quenching furnace according to claim 1, characterized in that: A plurality of fixed plates are arranged in the reaction cylinder, the plurality of fixed plates are arranged in the upper cavity and arranged in the vertical direction, and each fixed plate is provided with an air hole and a tapered hole, a plurality of air holes are provided, and the plurality of air holes penetrate the fixed plate in the vertical direction and are evenly distributed on the fixed plate; the tapered hole penetrates the fixed plate along the axial direction of the air guide tube, the air guide tube is arranged in the tapered hole, the tapered hole includes a large mouth end and a small mouth end, the small mouth end of the tapered hole is located below the large mouth end, and the diameter of the small mouth of the tapered hole is larger than the diameter of the air guide tube.

6. The methanol off-furnace cracking device for a salt bath quenching furnace according to claim 1, characterized in that: A slope is provided on a side of the support tube away from the filter screen, and the slope gradually moves away from the filter screen from a side close to the air duct to a side away from the air duct.

7. The methanol off-furnace cracking device for a salt bath quenching furnace according to claim 1, characterized in that: A partition is provided in the reaction cylinder, and the partition is located between the upper chamber and the lower chamber, and one end of the air guide tube passes through the partition and is fixedly connected to the partition; the heat exchange cylinder includes an air inlet cylinder, an air outlet cylinder, a first tube, a second tube and a connecting cover, the air inlet cylinder and the air outlet cylinder are sleeved on the air guide tube, and the air inlet cylinder and the air outlet cylinder are both located in the lower chamber; there are multiple first tubes and second tubes, one end of the multiple first tubes is fixedly installed on the air inlet cylinder and is connected to the air inlet cylinder, one end of the multiple second tubes is fixedly installed on the air outlet cylinder and is connected to the air outlet cylinder, the multiple first tubes and the multiple second tubes are evenly and alternately arranged around the air guide tube, the multiple first tubes and the multiple second tubes are spirally wound on the air guide tube and extend along the axial direction of the air guide tube, and a spacing is provided between adjacent first tubes and second tubes; the connecting cover is provided on one end of the air guide tube away from the lower chamber, one end of the multiple first tubes away from the air inlet cylinder and one end of the multiple second tubes away from the air outlet cylinder are connected to the connecting cover, and the multiple first tubes and the multiple second tubes are connected through the connecting cover.

8. The methanol off-furnace cracking device for a salt bath quenching furnace according to claim 2, characterized in that: A baffle and an air outlet are provided on the end cover, one branch tube in the catalytic tube abuts against the partition, and another branch tube in the catalytic tube abuts against the baffle, the air outlet is located on the side of the baffle away from the catalytic tube, and a plurality of through holes are opened on the baffle; an end cover and an air inlet are provided on the reaction tube, and the air inlet is connected to the lower cavity for introducing methanol in the superheater into the reaction tube.

9. The methanol off-furnace cracking device for a salt bath quenching furnace according to claim 1, characterized in that: One air guide pipe, a plurality of catalytic cylinders and one heat exchange cylinder form a catalytic group. A plurality of catalytic groups are arranged in the reaction cylinder, and the plurality of catalytic groups are evenly arranged in the reaction cylinder.

10. A method for cracking methanol outside a salt bath quenching furnace, characterized in that: Using the methanol off-furnace cracking device for a salt bath quenching furnace as claimed in any one of claims 1 to 9, and The following steps are involved: S1, methanol is vaporized after passing through the vaporizer; S2, the vaporized methanol is heated by a superheater; S3, the vaporized methanol after heating enters the lower chamber of the reactor, and then the vaporized methanol contacts the heat exchange cylinder through the air guide pipe, and the heat exchange cylinder heats the vaporized methanol to a preset temperature; S4, the vaporized methanol leaving the gas duct passes through the catalytic cylinder to undergo cracking reaction.

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