Cracking furnace with flow regulation and control function

Abstract

The invention discloses a cracking furnace with a flow regulation and control function, and relates to the technical field of cracking furnaces, the cracking furnace comprises a bearing device, a regulation and control device, a combustion device, a quench cooler and a steam pocket, the bearing device is communicated with the quench cooler, the steam pocket is communicated with the bearing device through a pipeline, the combustion device is communicated with the bearing device through a pipeline, and the regulation and control device is connected with the bearing device. The bearing device comprises a furnace body, the furnace body comprises a convection cavity and a radiation cavity, an anastomosis cavity is arranged between the convection cavity and the radiation cavity, the regulation and control device is arranged in the anastomosis cavity, the regulation and control device is used for regulating the heat exchange stroke of raw materials in the anastomosis cavity, and the space in the furnace body is distributed in a three-section manner, namely the convection cavity for preheating the raw materials and the radiation cavity for carrying out cracking reaction; by means of the split-cavity arrangement, the flue gas used for cracking can be sequentially communicated and flows out after multiple times of heat exchange, the utilization rate of heat is increased, and energy consumption is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of cracking furnaces, in particular to a cracking furnace with a flow control function. Background Art

[0002] Cracking furnaces are generally used for cracking reactions in petrochemical media. Through cracking reactions, macromolecular raw materials are split into substances with smaller molecules. For example, ethylene, propylene, tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, etc. are cracked into them.

[0003] The cracking reaction is generally carried out in the furnace chamber of the cracking furnace. The high temperature is provided by the combustion of fuel to break the long-chain hydrocarbons. Before the cracking reaction, the raw materials are preheated by burning flue gas, which can improve energy utilization and reduce energy consumption. However, due to the volatility of raw material transportation and the relatively fixed space of the cracking reaction, the general cracking furnace cannot automatically adjust the preheating time according to the feed amount of the raw material transportation, so that the temperature of the raw materials entering the furnace tube of the cracking furnace for the cracking reaction fluctuates. For example, patent CN111944556A provides a heat exchange system for an ethylene cracking furnace, which recovers the heat of the flue gas to preheat the raw materials. Combined with the attached figure, it can be seen that the raw material preheating stroke in the cracking process is fixed.

[0004] Therefore, conventional cracking furnaces cannot adaptively control fluctuations in raw material delivery. When overheated, they are prone to coking and forming a coke layer. When the temperature is insufficient, the cracking efficiency will be greatly affected and the demand for automated production cannot be met. Summary of the invention

[0005] The object of the present invention is to provide a cracking furnace with a flow control function to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions: The cracking furnace includes a carrying device, a regulating device, a combustion device, a quench cooler and a steam drum. The carrying device is connected to the quench cooler, the steam drum is connected to the carrying device pipeline, the combustion device is connected to the carrying device pipeline, the regulating device is connected to the carrying device, the carrying device includes a furnace body, the furnace body includes a convection cavity and a radiation cavity, an anastomotic cavity is provided between the convection cavity and the radiation cavity, the regulating device is placed in the anastomotic cavity, and the regulating device is used to adjust the heat exchange stroke of the raw material in the anastomotic cavity.

[0007] The raw materials are cracked by the cracking furnace. The furnace body of the supporting device is used to provide cracking space. The temperature required for the cracking reaction is increased by the combustion device. The control device is used to adjust the heat exchange stroke of the raw materials. According to the amount of raw material feed, the heat exchange stroke is adjusted in real time to ensure the heat exchange temperature. That is, the more raw material feed, the longer the heat exchange stroke is in the limited space in the matching cavity, thereby improving the heat exchange quality. The space in the furnace body adopts a three-stage distribution, namely, a convection cavity for preheating the raw materials, a radiation cavity for cracking reaction, and a matching cavity for connecting the two cavities and adjusting the heat exchange stroke. Through the chamber setting, the flue gas used for cracking can be connected in sequence and flow out after multiple heat exchanges, thereby improving the utilization rate of heat and reducing energy consumption. The steam drum is used to provide dilution steam and enters the convection cavity together with the raw materials. The gas after the cracking reaction is oil-cooled by the quench cooler to prevent the cracking gas from secondary reaction and affecting the cracking quality.

[0008] Furthermore, the support device also includes a feed pipe, a steam pipe and a furnace pipe, one end of the feed pipe is inserted into the convection cavity, the feed pipe is connected to the steam pipe, the furnace pipe is placed in the radiation cavity, and the drum outlet is connected to the steam pipe pipeline; The regulating device includes a connecting pipe and an extension component. The end of the feed pipe is connected to the connecting pipe, the connecting pipe is placed in the anastomosis cavity, the end of the connecting pipe is connected to the furnace pipe, the length of the connecting pipe is adjustable, the extension component is placed in the connecting pipe, and the extension component is used to adjust the heat exchange stroke of the connecting pipe.

[0009] The feed pipe is used to supply raw materials. The steam pipe is connected to the steam drum to provide dilution steam to the feed pipe. The raw materials enter the convection chamber and are preheated by the high-temperature flue gas in the convection chamber. After preheating, the raw materials enter the connecting pipe. The connecting pipe adopts an adjustable length pipe. When the feed amount of the raw materials changes, the length and inclination angle of the connecting pipe are controlled by the extension component, so as to adjust the preheating time of the raw materials, so that the temperature of the raw materials entering the furnace tube remains stable, thereby ensuring the quality of cracking.

[0010] Furthermore, the connecting pipe is provided with an induction section and a stretching section in sequence along the feeding direction, the induction section is connected to the end of the feed pipe, the end of the stretching section is connected to the furnace pipe, the connecting pipe is provided with a transmission groove, the transmission groove is located in the induction section, the extension component includes a windward plate, a transmission sheet and an elastic sheet, the transmission sheet and the transmission groove are slidably connected, the windward plate and the transmission sheet are tightly connected, the elastic sheet is arranged in an arc shape, one end of the elastic sheet is tightly connected to the wall of the induction section, and the other end is tightly connected to the end of the transmission sheet.

[0011] The connecting pipe is set up in sections, and the inlet of the induction section is connected to the end of the feed pipe. When the preheated raw materials enter the connecting pipe, the temperature is fine-tuned according to the feed amount of the raw materials. When the raw materials impact the windward plate, the impact energy conversion drives the transmission plate to move horizontally along the transmission groove. The other end of the transmission plate is connected to the elastic plate. When the transmission plate moves, one end of the elastic plate is fixed on the wall of the induction section pipe, and the other end is linked to the transmission plate. The elastic plate will deform as the transmission plate moves, thereby adjusting the curvature. In the initial state, the curvature of the elastic sheet is the largest. When the raw material feed is the standard value, the windward plate is driven to move to the calibrated position, and the elastic sheet is deformed through the transmission sheet, so that the curvature reaches the standard value. When the airflow flows through the curved surface of the elastic sheet, it moves along the curved surface under the action of the wall attachment, and the jet rushes to the wall of the stretching section. The length from contact to separation of the elastic sheet is defined as the wall attachment length, thereby generating a lateral force on the stretching section. This lateral force has a vertical component, and the stretching section is stretched by this component until it reaches a stable length; when the raw material feed increases, the impact force on the windward plate increases, the elastic sheet is further deformed, and the curvature decreases, thereby extending the wall attachment length. As the wall attachment length is extended, the angle between the jet direction after separation and the horizontal direction increases, thereby increasing the vertical component, driving the stretching section to further stretch, extending the heat exchange stroke, and ensuring the heat exchange quality; on the contrary, the heat exchange stroke is reduced, the heat exchange amount is reduced, and the heat exchange efficiency is ensured.

[0012] Furthermore, the transmission groove is located at the upper part of the tube wall of the stretching section.

[0013] By arranging the transmission groove upward, the elastic sheet is located at the upper part, so that the vertical component of the force generated by the wall attachment effect is directed upward, which facilitates the adjustment of the heat exchange stroke.

[0014] Furthermore, the thickness of the elastic sheet gradually decreases along the feeding direction.

[0015] By setting the thickness decreasing gradually, the response sensitivity is improved when the heat exchange stroke is extended.

[0016] Furthermore, the combustion device includes a burner, an air preheater and a burner. A plurality of burners are arranged along the side wall and the bottom of the radiation cavity. The air preheater is placed in the convection cavity. The burner and air preheater outlets are respectively connected to the burner pipe.

[0017] A burner is provided for supplying fuel, and an air preheater is placed in the convection chamber. The air is preheated by flue gas and sent into the burner for combustion along with the fuel. The combustion generates flue gas and the raw materials inside are cracked through the furnace tube.

[0018] As an optimization, the cracking furnace also includes a water supply pipe, which passes through the convection chamber, and the end of the water supply pipe is connected to the steam drum. By setting up the water supply pipe to supply water to the steam drum, it is convenient for the steam drum to generate steam. When the water supply pipe passes through the convection chamber, the water in the water supply pipe is heated by the flue gas, thereby improving the heat recovery efficiency.

[0019] As an optimization, the water supply pipe is a coil structure, a smoke pipe is provided at the upper end of the furnace body, the upper end of the convection cavity is connected to the smoke pipe, the water supply pipe is located below the smoke pipe, and the water supply pipe is located on the upper layer of the feed pipe. The water supply pipe is arranged through a coil to extend the heat exchange time in the convection cavity and improve the heat recovery efficiency. The water supply pipe is placed on the upper side of the feed pipe to prevent the flue gas from affecting the preheating of the raw materials in the feed pipe.

[0020] As an optimization, the water supply pipe is arranged in a spiral along the same plane, and the outlet of the water supply pipe is located at the bottom of the spiral plane. Through the spiral arrangement, the inlet is located on the outside, so that when the water body is preheated, the temperature increases as the spiral moves toward the middle. By placing the outlet downward, the flue gas in the convection chamber gradually decreases during the upward flow, so that the water outlet and the flue gas always maintain a large temperature difference, ensuring the preheating temperature of the water body.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: the connecting pipe adopts a pipe with adjustable length. When the feed amount of the raw material changes, the length and inclination angle of the connecting pipe are controlled by the extension component, thereby adjusting the preheating time of the raw material, so that the temperature of the raw material entering the furnace tube remains stable, thereby ensuring the quality of cracking; since one end of the elastic sheet is fixed on the wall of the induction section tube and the other end is linked to the transmission sheet, the elastic sheet will deform as the transmission sheet moves, thereby adjusting the curvature. In the initial state, the curvature of the elastic sheet is the largest. When the raw material feed is the standard value, the windward plate is driven to move to the calibrated position, and the elastic sheet is deformed through the transmission sheet, so that the curvature reaches the standard value. When the airflow flows through the curved surface of the elastic sheet, it moves along the curved surface under the action of the wall attachment, and the jet rushes to the wall of the stretching section. The length from contact to separation of the elastic sheet is defined as the wall attachment length, thereby generating a lateral force on the stretching section. This lateral force has a vertical component, and the stretching section is stretched by this component until it reaches a stable length; when the raw material feed increases, the impact force on the windward plate increases, the elastic sheet is further deformed, and the curvature decreases, thereby extending the wall attachment length. As the wall attachment length is extended, the angle between the jet direction after separation and the horizontal direction increases, thereby increasing the vertical component, driving the stretching section to further stretch, extending the heat exchange stroke, and ensuring the heat exchange quality; on the contrary, the heat exchange stroke is reduced, the heat exchange amount is reduced, and the heat exchange efficiency is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the furnace structure of the present invention; Figure 3 It is a schematic diagram of the structure of the extended-range component of the present invention; Figure 4 for Figure 3 A magnified view of a part of the view; Figure 5 for Figure 3 A magnified view of a part B of the view; Figure 6 It is a schematic diagram of the connecting pipe structure of the present invention; Figure 7 It is a schematic diagram of the radiation cavity structure of the present invention.

[0023] In the figure: 1. bearing device; 11. furnace body; 111. convection chamber; 112. matching chamber; 113. radiation chamber; 12. feed pipe; 13. steam pipe; 14. furnace pipe; 2. regulating device; 21. connecting pipe; 211. induction section; 212. stretching section; 213. transmission groove; 22. extension component; 221. windward plate; 222. transmission sheet; 223. elastic sheet; 3. combustion device; 31. burner; 32. air preheater; 33. burner; 4. quencher; 5. steam drum; 6. water supply pipe; 7. smoke pipe. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Example: Figure 1-Figure 7 As shown, the present invention provides a technical solution for a cracking furnace with a flow control function.

[0026] The cracking furnace includes a carrying device 1, a regulating device 2, a combustion device 3, a quencher 4 and a steam drum 5. The carrying device 1 is connected to the quencher 4, the steam drum 5 is connected to the carrying device 1 through a pipeline, the combustion device 3 is connected to the carrying device 1 through a pipeline, the regulating device 2 is connected to the carrying device 1, the carrying device 1 includes a furnace body 11, the furnace body 11 includes a convection cavity 111 and a radiation cavity 113, an anastomotic cavity 112 is provided between the convection cavity 111 and the radiation cavity 113, the regulating device 2 is placed in the anastomotic cavity 112, and the regulating device 2 is used to adjust the heat exchange stroke of the raw material in the anastomotic cavity 112.

[0027] The raw material is cracked by the cracking furnace. The furnace body 11 of the carrier device 1 is used to provide cracking space. The temperature required for the cracking reaction is increased by the combustion device 3. The control device 2 is used to adjust the heat exchange stroke of the raw material. According to the amount of raw material fed, the heat exchange stroke is adjusted in real time to ensure the heat exchange temperature. That is, the more raw material is fed, the longer the heat exchange stroke is in the limited space in the matching cavity 112, thereby improving the heat exchange quality. The space in the furnace body 11 adopts a three-stage distribution, namely, a convection cavity for preheating the raw material, a radiation cavity 113 for cracking reaction, and a matching cavity 112 for connecting the two cavities and adjusting the heat exchange stroke. Through the chamber setting, the flue gas used for cracking can be connected in sequence and flow out after multiple heat exchanges, thereby improving the utilization rate of heat and reducing energy consumption. The steam drum 5 is used to provide dilution steam and enters the convection cavity together with the raw material. The gas after the cracking reaction is oil-cooled by the quench cooler 4 to prevent the cracking gas from secondary reaction and affecting the cracking quality.

[0028] Furthermore, the carrier device 1 further comprises a feed pipe 12, a steam pipe 13 and a furnace pipe 14, one end of the feed pipe 12 is inserted into the convection chamber 111, the feed pipe 12 is connected to the steam pipe 13, the furnace pipe 14 is placed in the radiation chamber 113, and the outlet of the steam drum 5 is connected to the steam pipe 13; The regulating device 2 includes a connecting pipe 21 and an extension component 22. The end of the feed pipe 12 is connected to the connecting pipe 21, and the connecting pipe 21 is placed in the anastomotic cavity 112. The end of the connecting pipe 21 is connected to the furnace pipe 14. The length of the connecting pipe 21 is adjustable. The extension component 22 is placed in the connecting pipe 21. The extension component 22 is used to adjust the heat exchange stroke of the connecting pipe 21.

[0029] The feed pipe 12 is used to supply raw materials, and the steam pipe 13 is connected to the steam drum 5 to provide dilution steam into the feed pipe 12. The raw materials enter the convection chamber 111 and are preheated by the high-temperature flue gas in the convection chamber 111. After preheating, the raw materials enter the connecting pipe 21. The connecting pipe 21 adopts a pipe with adjustable length. When the feed amount of the raw materials changes, the length and inclination angle of the connecting pipe 21 are controlled by the extension component 22, thereby adjusting the preheating time of the raw materials, so that the temperature of the raw materials entering the furnace tube 14 remains stable, thereby ensuring the quality of cracking.

[0030] Furthermore, the connecting pipe 21 is provided with an induction section 211 and a stretching section 212 in sequence along the feeding direction. The induction section 211 is connected to the end of the feed pipe 12, and the end of the stretching section 212 is connected to the furnace pipe 14. A transmission groove 213 is provided on the connecting pipe 21, and the transmission groove 213 is located in the induction section 211. The extension component 22 includes a windward plate 221, a transmission sheet 222 and an elastic sheet 223. The transmission sheet 222 and the transmission groove 213 are slidably connected. The windward plate 221 and the transmission sheet 222 are tightly connected. The elastic sheet 223 is arranged in an arc shape. One end of the elastic sheet 223 is tightly connected to the tube wall of the induction section 211, and the other end is tightly connected to the end of the transmission sheet 222.

[0031] The connecting pipe 21 is set in sections, and the inlet of the induction section 211 is connected to the end of the feed pipe 12. When the preheated raw materials enter the connecting pipe 21, the temperature is finely adjusted according to the feed amount of the raw materials. When the raw materials impact the windward plate 221, the impact energy conversion drives the transmission sheet 222 to move laterally along the transmission groove 213. The other end of the transmission sheet 222 is connected to the elastic sheet 223. When the transmission sheet 222 moves, since one end of the elastic sheet 223 is fixed on the tube wall of the induction section 211 and the other end is linked to the transmission sheet 222, the elastic sheet 223 will deform as the transmission sheet 222 moves, thereby adjusting the curvature. In the initial state, the curvature of the elastic sheet 223 is the largest. When the raw material feed is at the standard value, the windward plate 221 is driven to move to the calibrated position, and the elastic sheet 223 is driven to deform through the transmission sheet 222, so that the curvature reaches the standard value. When the airflow flows through the curved surface of the elastic sheet 223, it moves along the curved surface under the action of the wall attachment, and the jet rushes toward the wall of the stretching section 212. The length from contact to separation of the elastic sheet 223 is defined as the wall attachment length, thereby generating a lateral force on the stretching section 212. This lateral force has a vertical direction. The component force drives the stretching section 212 to stretch until it reaches a stable length; when the raw material feed increases, the impact force on the windward plate 221 increases, the elastic sheet 223 is further deformed, and the curvature decreases, thereby extending the wall attachment length. As the wall attachment length increases, the angle between the jet direction after separation and the horizontal direction increases, thereby increasing the vertical component force, driving the stretching section 212 to stretch further, extending the heat exchange stroke, and ensuring the heat exchange quality; conversely, the heat exchange stroke is reduced, the heat exchange amount is reduced, and the heat exchange efficiency is guaranteed.

[0032] Furthermore, the transmission groove 213 is located on the upper part of the tube wall of the stretching section 212 .

[0033] By placing the transmission groove 213 upward, the elastic sheet 223 is located at the upper part, so that the vertical component of the force generated by the wall effect is directed upward, which facilitates the adjustment of the heat exchange stroke.

[0034] Furthermore, the thickness of the elastic sheet 223 gradually decreases along the feeding direction.

[0035] By setting the thickness decreasing gradually, the response sensitivity is improved when the heat exchange stroke is extended.

[0036] Furthermore, the combustion device 3 includes a burner 31, an air preheater 32 and a burner 33. A plurality of burners 33 are provided along the side wall and the bottom of the radiation cavity 113. The air preheater 32 is placed in the convection cavity 111. The outlets of the burner 31 and the air preheater 32 are respectively connected to the burner 33 pipeline.

[0037] A burner 31 is provided for supplying fuel, and an air preheater 32 is placed in the convection chamber 111 . Air is preheated by flue gas and sent to the burner 33 for combustion along with the fuel. The combustion generates flue gas and the raw materials inside are cracked through the furnace tube 14 .

[0038] As an optimization, the cracking furnace further includes a water supply pipe 6, which passes through the convection chamber 111, and the end of the water supply pipe 6 is connected to the steam drum 5. The water supply pipe 6 is provided to supply water to the steam drum 5, so that the steam drum 5 generates steam. When the water supply pipe 6 passes through the convection chamber 111, the water in the water supply pipe 6 is heated by the flue gas, thereby improving the heat recovery efficiency.

[0039] As an optimization, the water supply pipe 6 is a coil structure, a smoke pipe 7 is provided at the upper end of the furnace body 11, the upper end of the convection chamber 111 is connected to the smoke pipe 7, the water supply pipe 6 is located below the smoke pipe 7, and the water supply pipe 6 is located on the upper layer of the feed pipe 12. The water supply pipe 6 is arranged through a coil, which prolongs the heat exchange time in the convection chamber 111 and improves the heat recovery efficiency. The water supply pipe 6 is placed on the upper side of the feed pipe 12 to prevent the flue gas from affecting the preheating of the raw materials in the feed pipe 12.

[0040] As an optimization, the water supply pipe 6 is arranged in a spiral along the same plane, and the outlet of the water supply pipe 6 is located at the lower part of the spiral plane. Through the spiral arrangement, the inlet is located on the outside, so that when the water body is preheated, the temperature increases as the spiral moves toward the middle. By placing the outlet downward, the flue gas in the convection chamber 111 gradually decreases during the upward flow, so that the water outlet and the flue gas always maintain a large temperature difference, ensuring the preheating temperature of the water body.

[0041] The working principle of the present invention is as follows: the connecting pipe 21 adopts a pipe with adjustable length. When the feed amount of the raw material changes, the length and inclination angle of the connecting pipe 21 are controlled by the extension component 22, thereby adjusting the preheating time of the raw material, so that the temperature of the raw material entering the furnace tube 14 remains stable, thereby ensuring the quality of cracking; since one end of the elastic sheet 223 is fixed on the tube wall of the induction section 211 and the other end is linked to the transmission sheet 222, the elastic sheet 223 will deform as the transmission sheet 222 moves, thereby adjusting the curvature. In the initial state, the curvature of the elastic sheet 223 is the largest. When the raw material feed is at the standard value, the windward plate 221 is driven to move to the calibrated position, and the elastic sheet 223 is driven to deform through the transmission sheet 222, so that the curvature reaches the standard value. When the airflow flows through the curved surface of the elastic sheet 223, it moves along the curved surface under the action of the wall attachment, and the jet rushes toward the wall of the stretching section 212. The length from contact to separation of the elastic sheet 223 is defined as the wall attachment length, thereby generating a lateral force on the stretching section 212. This lateral force has a vertical direction. The component force drives the stretching section 212 to stretch until it reaches a stable length; when the raw material feed increases, the impact force on the windward plate 221 increases, the elastic sheet 223 is further deformed, and the curvature decreases, thereby extending the wall attachment length. As the wall attachment length increases, the angle between the jet direction after separation and the horizontal direction increases, thereby increasing the vertical component force, driving the stretching section 212 to stretch further, extending the heat exchange stroke, and ensuring the heat exchange quality; conversely, the heat exchange stroke is reduced, the heat exchange amount is reduced, and the heat exchange efficiency is guaranteed.

[0042] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A cracking furnace with flow control function, characterized in that: The cracking furnace comprises a carrying device, a regulating device, a combustion device, a quench cooler and a steam drum, wherein the carrying device is connected to the quench cooler, the steam drum is connected to the carrying device through a pipeline, the combustion device is connected to the carrying device through a pipeline, the regulating device is connected to the carrying device, the carrying device comprises a furnace body, the furnace body comprises a convection cavity and a radiation cavity, an anastomotic cavity is provided between the convection cavity and the radiation cavity, the regulating device is placed in the anastomotic cavity, and the regulating device is used to adjust the heat exchange stroke of the raw materials in the anastomotic cavity; The regulating device comprises a connecting pipe and an extension component, the end of the feed pipe is connected to the connecting pipe, the connecting pipe is placed in the anastomotic cavity, the end of the connecting pipe is connected to the furnace pipe, the length of the connecting pipe is adjustable, the extension component is placed in the connecting pipe, and the extension component is used to adjust the heat exchange stroke of the connecting pipe; The connecting pipe is provided with an induction section and a stretching section in sequence along the feeding direction, the induction section is connected with the end pipe of the feed pipe, the end of the stretching section is connected with the furnace pipe pipe, the connecting pipe is provided with a transmission groove, the transmission groove is located in the induction section, the extension component includes a windward plate, a transmission sheet and an elastic sheet, the transmission sheet and the transmission groove are slidably connected, the windward plate and the transmission sheet are tightly connected, the elastic sheet is arranged in an arc shape, one end of the elastic sheet is tightly connected to the wall of the induction section pipe, and the other end is tightly connected to the end of the transmission sheet.

2. The cracking furnace with flow control function according to claim 1, characterized in that: The supporting device also includes a feed pipe, a steam pipe and a furnace pipe. One end of the feed pipe is inserted into the convection cavity, the feed pipe is connected to the steam pipe, the furnace pipe is placed in the radiation cavity, and the steam drum outlet is connected to the steam pipe pipeline.

3. The cracking furnace with flow control function according to claim 2, characterized in that: The transmission groove is located at the upper part of the tube wall of the stretching section.

4. The cracking furnace with flow control function according to claim 2, characterized in that: The thickness of the elastic sheet gradually decreases along the feeding direction.

5. The cracking furnace with flow control function according to claim 1, characterized in that: The combustion device comprises a burner, an air preheater and a burner nozzle. A plurality of burners are arranged along the side wall and the bottom of the radiation cavity. The air preheater is placed in the convection cavity. The burner and air preheater outlets are respectively connected to the burner nozzle pipeline.

6. The cracking furnace with flow control function according to claim 5, characterized in that: The cracking furnace also includes a water supply pipe, which passes through the convection chamber, and the end of the water supply pipe is connected to the steam drum.

7. The cracking furnace with flow control function according to claim 6, characterized in that: The water supply pipe is a coil structure, a smoke pipe is arranged at the upper end of the furnace body, the upper end of the convection cavity is connected with the smoke pipe, the water supply pipe is located below the smoke pipe, and the water supply pipe is located on the upper layer of the feed pipe.

8. The cracking furnace with flow control function according to claim 7, characterized in that: The water supply pipes are arranged in a spiral along the same plane, and the outlets of the water supply pipes are located at the lower part of the spiral plane.

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