Ethylene cracking furnace

Abstract

The utility model discloses an ethylene cracking furnace, which relates to the technical field of chemical equipment and comprises a furnace body, the furnace body comprises a convection section and a radiation section, the joint of the radiation section and the convection section is of an inclined structure, and a combustion chamber is arranged between the two radiation sections. The convection section, the radiation section and the combustion chamber are arranged, the convection section and the radiation section form an inverted Y-shaped structure, so that the joint of the convection section and the radiation section is of an inclined structure, smoke is guided, smoke backflow is limited, and the internal temperature of the radiation section is influenced; the guide plate can guide high-temperature flue gas and flame sprayed by the combustion nozzle to one side of the multiple partition plates, and the high-temperature flue gas and the flame are uniformly dispersed on the outer side of the cracking pipe under the guide of the partition plates, so that the heating uniformity of the cracking pipe is ensured, and the stable proceeding of cracking reaction in the radiation section is ensured.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, and in particular to an ethylene cracking furnace. Background Technology

[0002] Ethylene cracking furnaces are used to process cracked gas, and there are various types, including dual-radiation chamber, single-radiation chamber, and millisecond furnaces. The ethylene cracking furnace is the core equipment of an ethylene production plant. Its main function is to process various raw materials such as natural gas, refinery gas, crude oil, and naphtha into cracked gas, which is then supplied to other ethylene plants for final processing into ethylene, propylene, and various by-products. The production capacity and technological sophistication of the ethylene cracking furnace directly determine the production scale, output, and product quality of the entire ethylene plant. Therefore, the ethylene cracking furnace plays a leading role in ethylene production plants and even in the entire petrochemical production process.

[0003] In existing technologies, ethylene cracking furnaces mainly include a radiant section, a convection section, and a quenching system. Ethylene feedstock undergoes a cracking reaction when heated inside the radiant section, causing chemical bonds to break. The temperature inside the radiant section has a significant impact on the cracking reaction. Existing ethylene cracking furnaces use coils as radiant tubes inside the radiant section. However, while the coils can improve the heating effect of the feedstock inside the radiant section, their circular arrangement can easily cause uneven heating, resulting in incomplete cracking reactions.

[0004] Therefore, it is necessary to invent an ethylene cracking furnace to solve the above problems. Utility Model Content

[0005] The purpose of this invention is to provide an ethylene cracking furnace to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: an ethylene cracking furnace, comprising a furnace body, the furnace body comprising a convection section and a radiation section, the radiation section having two symmetrically distributed sections, both of which are fixedly located at the bottom of the convection section and connected to the convection section, the connection between the radiation section and the convection section being an inclined structure, a combustion chamber being provided between the two radiation sections, two symmetrically distributed combustion ports penetrating through the inner walls on both sides of the combustion chamber, a fixed seat being fixedly provided inside the combustion port, and multiple combustion nozzles being fixedly provided sequentially from bottom to top on one side of the fixed seat, the multiple combustion nozzles being located inside the radiation section, arc-shaped guide plates being provided at both ends on the side of the radiation section away from the combustion chamber, the positions of the two guide plates corresponding to the two combustion ports respectively, and multiple partitions being fixedly provided on the inner wall of the radiation section near the combustion chamber, with multiple cracking tubes being fixedly provided sequentially between the multiple partitions;

[0007] An air intake hood is fixedly provided on the outer wall of the radiation section. Multiple fixed plates corresponding to the guide plate are fixedly provided inside the air intake hood. Multiple air intake slots are provided through the top of the outer wall of the air intake hood. An inclined baffle is fixedly provided at the top of the inner side of the radiation section, and the baffle is located between the air intake hood and the radiation section. Multiple air intake nozzles are fixedly provided at the bottom inner side of the baffle.

[0008] Preferably, the plurality of air inlets are staggered with the plurality of partitions, and the plurality of air inlets are all configured as an upwardly tapered structure.

[0009] Preferably, each of the plurality of air inlets has an air inlet hole through it, and one end of the air inlet hole is connected to the air inlet cover.

[0010] Preferably, the pyrolysis tube is a coil, and a convection tube is fixedly provided at the top end of the pyrolysis tube, and the convection tube is located inside the convection section.

[0011] Preferably, a quench boiler is fixedly installed on both sides of the convection section.

[0012] Preferably, multiple gas pipes are fixedly provided on the outer side of the fixing base, and the multiple gas pipes are respectively connected to multiple combustion nozzles.

[0013] The technical effects and advantages of this utility model are as follows:

[0014] 1. This utility model sets up a convection section, a radiation section, and a combustion chamber. The convection section and the radiation section form an inverted "Y" shape structure, so that the connection between the convection section and the radiation section is an inclined structure. This is to guide the flue gas and limit the backflow of flue gas from affecting the internal temperature of the radiation section. Furthermore, the convection section is equipped with guide plates and multiple baffles. The guide plates can guide the high-temperature flue gas and flame ejected from the combustion nozzle to one side of the multiple baffles. Under the guidance of the baffles, the high-temperature flue gas and flame are evenly dispersed on the outside of the pyrolysis tube to ensure the uniformity of heating of the pyrolysis tube, thereby ensuring the stable progress of the pyrolysis reaction inside the radiation section.

[0015] 2. This utility model, by setting up an air intake hood and an air intake nozzle, with the air intake hood located on the outside of the radiation section, allows the high-temperature flue gas inside the radiation section to heat the air intake hood. When the high-temperature flue gas moves inside the radiation section, the high-speed flow of the high-temperature flue gas creates a Venturi effect at the end of the air intake nozzle, and under the Venturi effect, it draws air from inside the air intake hood to assist the combustion of the high-temperature flue gas and fuel, thereby further ensuring the temperature stability inside the radiation section, and thus ensuring the stable progress of the pyrolysis reaction. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0017] Figure 2This is a cross-sectional view of the overall structure of this utility model.

[0018] Figure 3 For the present utility model Figure 2 Enlarged schematic diagram of the structure at point A in the middle.

[0019] Figure 4 This is a schematic diagram of the internal structure of the radiating section of this utility model.

[0020] In the diagram: 1. Furnace body; 2. Convection section; 3. Radiant section; 4. Combustion chamber; 5. Combustion port; 6. Fixing base; 7. Gas pipe; 8. Guide plate; 9. Baffle plate; 10. Cracking pipe; 11. Air inlet hood; 12. Fixing plate; 13. Air inlet slot; 14. Baffle; 15. Air inlet nozzle; 16. Air inlet hole; 17. Convection pipe; 18. Quenching boiler. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] This utility model provides, for example Figure 1-4 An ethylene cracking furnace is shown, including a furnace body 1. The furnace body 1 includes a convection section 2 and a radiation section 3. Two radiation sections 3 are symmetrically distributed, and both radiation sections 3 are fixed at the bottom of the convection section 2 and connected to the convection section 2. The connection between the radiation section 3 and the convection section 2 is an inclined structure. A combustion chamber 4 is provided between the two radiation sections 3. Two symmetrically distributed combustion ports 5 are provided through the inner walls on both sides of the combustion chamber 4. A fixing seat 6 is fixed inside the combustion port 5. Multiple combustion nozzles are fixed from bottom to top on one side of the fixing seat 6, and the multiple combustion nozzles are all located inside the radiation section 3. Multiple gas pipes 7 are fixed on the outside of the fixing seat 6, and the multiple gas pipes 7 are respectively connected to the multiple combustion nozzles.

[0023] The interior of the radiant section 3 is provided with arc-shaped guide plates 8 at both ends on the side away from the combustion chamber 4, and the positions of the two guide plates 8 correspond to the two combustion ports 5 respectively. Multiple baffles 9 are fixedly provided on the inner wall of the radiant section 3 on the side close to the combustion chamber 4. Multiple cracking tubes 10 are fixedly provided between the multiple baffles 9 in sequence. The ethylene feedstock undergoes cracking reaction inside the cracking tubes 10.

[0024] An air inlet hood 11 is fixedly installed on the outer wall of the radiation section 3. Multiple fixed plates 12 corresponding to the guide plate 8 are fixedly installed inside the air inlet hood 11. Multiple air inlet slots 13 are provided through the top of the outer wall of the air inlet hood 11. An inclined baffle 14 is fixedly installed at the top of the inside of the radiation section 3. The baffle 14 is located between the air inlet hood 11 and the radiation section 3. Multiple air inlets 15 are fixedly installed at the bottom of the inner side of the baffle 14. The baffle 14 is used to guide the high-temperature flue gas to move in an upward direction to achieve continuous flow of flue gas inside the radiation section 3.

[0025] Multiple air inlets 15 are staggered with multiple partitions 9, and each air inlet 15 is designed as an upwardly tapered structure. Each air inlet 15 has an air inlet hole 16 running through its interior, and one end of the air inlet hole 16 is connected to the air inlet cover 11. The design of the upwardly tapered structure makes the end of the air inlet 15 form a negative pressure zone, so that the end of the air inlet 15 generates a Venturi effect.

[0026] The cracking pipe 10 is configured as a coil, and a convection pipe 17 is fixedly provided at the top end of the cracking pipe 10. The convection pipe 17 is located inside the convection section 2. The cracking pipe 10 and the convection pipe 17 form a guide pipe for ethylene feedstock.

[0027] Both sides of the convection section 2 are fixedly equipped with quench boilers 18, which are used to realize the waste heat recovery of high temperature flue gas.

[0028] Working principle of this utility model:

[0029] In operation, the feedstock for ethylene cracking is fed into the cracking tube 10, while the fuel gas is delivered to the fuel gas nozzle via the fuel gas pipe 7. The fuel gas ejected from the nozzle, after being ignited, enters the radiant section 3. The high-temperature flue gas generated by the fuel gas is guided by the guide plate 8 and diffuses evenly along the inner wall of the radiant section 3, dispersing into multiple baffles 9. Inside the baffles 9, the high-temperature flue gas heats the multiple cracking tubes 10 through thermal radiation, creating a high-temperature environment inside the cracking tubes 10. At this time, the chemical bonds of the ethylene cracking feedstock inside the cracking tubes 10 break under the high temperature, resulting in a cracking reaction. Simultaneously, the high-temperature flue gas moves upward as it enters the baffles 9 and is guided by the baffles 14 towards convection. In the second stage of the process, the high-temperature flue gas with a relatively high flow rate flows through the inlet nozzle 15, causing a Venturi effect to form at the end of the inlet nozzle 15. At this time, the air in the inlet hood 11 enters the radiation section 3 through the inlet nozzle 15 and the inlet hole 16 under the Venturi effect. The air mixes with the unburned fuel gas in the high-temperature flue gas, causing the fuel gas to burn again, so as to ensure the temperature inside the radiation section 3 is stable and also avoid the waste caused by the incomplete combustion of the fuel gas. Then, the high-temperature flue gas moves upward and enters the convection section 2. At this time, the quench boiler 18 can recover the waste heat in the high-temperature flue gas. At this time, the ethylene feedstock after cracking enters the convection section 2 through the convection pipe 17 and then is discharged. At this time, the cracking process of ethylene can be completed.

[0030] It should be noted that in this embodiment, the convection section 2, the radiation section 3, and the quench boiler 18 all adopt the corresponding structures in the prior art. This embodiment only improves the number and position of the radiation section 3. Furthermore, the air inlet slot 13 on the air inlet hood 11 can be connected to the oxygen storage tank, thereby directly supplying oxygen to the inside of the device to ensure the combustion effect of the gas. It should be further noted that in this embodiment, the gas pipe 7 and the combustion nozzle can be selected according to the needs of other fuels without restriction, provided that their combustion effect is guaranteed.

[0031] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An ethylene cracking furnace comprising a furnace body (1), characterized in that: The furnace body (1) includes a convection section (2) and a radiation section (3). The radiation section (3) has two symmetrically distributed sections, and both radiation sections (3) are fixedly located at the bottom end of the convection section (2) and connected to the convection section (2). The connection between the radiation section (3) and the convection section (2) is designed as an inclined structure. A combustion chamber (4) is provided between the two radiation sections (3). Two symmetrically distributed combustion ports (5) are provided through the inner walls on both sides of the combustion chamber (4). A fixing seat (6) is fixedly provided inside the combustion port (5). The fixed base (6) has multiple combustion nozzles fixedly arranged from bottom to top on one side, and the multiple combustion nozzles are all located inside the radiation section (3). The two ends of the side of the radiation section (3) away from the combustion chamber (4) are provided with arc-shaped guide plates (8), and the positions of the two guide plates (8) correspond to the two combustion ports (5) respectively. The inner wall of the radiation section (3) near the combustion chamber (4) is fixedly provided with multiple partitions (9), and multiple pyrolysis tubes (10) are fixedly arranged between the multiple partitions (9). An air intake hood (11) is fixedly provided on the outer side wall of the radiation section (3). Multiple fixing plates (12) corresponding to the guide plate (8) are fixedly provided inside the air intake hood (11). Multiple air intake slots (13) are provided through the top of the outer side wall of the air intake hood (11). An inclined baffle (14) is fixedly provided at the top of the inner side of the radiation section (3). The baffle (14) is located between the air intake hood (11) and the radiation section (3). Multiple air inlets (15) are fixedly provided at the bottom inner side of the baffle (14).

2. An ethylene cracker furnace according to claim 1, characterized in that: The multiple air inlets (15) are staggered with the multiple partitions (9), and the multiple air inlets (15) are all designed as upward-sloping conical structures.

3. An ethylene cracker furnace according to claim 2, characterized in that: Each of the multiple air inlets (15) has an air inlet hole (16) extending through its interior, and one end of the air inlet hole (16) is connected to the air inlet cover (11).

4. An ethylene cracker furnace as claimed in claim 1, characterized in that: The pyrolysis tube (10) is configured as a coil, and a convection tube (17) is fixedly provided at the top end of the pyrolysis tube (10), and the convection tube (17) is located inside the convection section (2).

5. An ethylene cracker furnace as claimed in claim 1, characterized in that: Both sides of the convection section (2) are fixedly equipped with quench boilers (18).

6. An ethylene cracker furnace as claimed in claim 1, characterized in that: Multiple gas pipes (7) are fixedly provided on the outside of the fixed base (6), and the multiple gas pipes (7) are respectively connected to multiple combustion nozzles.

Images