Waste gas treatment mechanism of steam thermal cracking furnace

Abstract

The utility model discloses a waste gas treatment mechanism of a steam thermal cracking furnace. The waste gas treatment mechanism comprises a gas feeding pipe, a direct combustion furnace, a heat exchanger, an oxygen supplementing air fan and an exhaust funnel, the direct combustion furnace comprises a waste gas inlet, an air inlet and an air outlet; the heat exchanger comprises a refrigerant inlet, a refrigerant outlet, a heating medium inlet and a heating medium outlet, and the waste gas inlet is communicated with the gas supply pipe; the air inlet is communicated with the refrigerant outlet, the refrigerant inlet is connected with the oxygenating air fan, and the oxygenating air fan is used for conveying external air to flow through the first channel and then enter the direct combustion furnace; the gas outlet is communicated with the heating medium inlet, the heating medium outlet is connected with the exhaust funnel, and purified gas flows through the second channel and then is exhausted through the exhaust funnel; external air and purified gas flow in the first channel and the second channel and exchange heat, so that the temperature of the air rises. Waste gas is purified through combustion, the purified gas enters the heat exchanger, the heat exchanger is used for heating air, heat loss is reduced, and the energy utilization rate is increased.

Description

Technical Field

[0001] This utility model relates to the field of environmental protection equipment technology, and in particular to a steam pyrolysis furnace exhaust gas treatment mechanism. Background Technology

[0002] Steam cracking furnaces are crucial equipment in the petrochemical industry, primarily used for the thermal cracking of petroleum hydrocarbons. Through the synergistic effect of high temperature and steam, they facilitate complex chemical reactions in hydrocarbon feedstocks with relatively large molecular weights and high boiling points, transforming them into smaller molecule products such as olefins with relatively small molecular weights and low boiling points.

[0003] During the operation of a steam cracking furnace, waste gases such as hydrogen and hydrides are generated. After condensation in a condenser, part of the waste gas liquefies into an oil-water mixture, while the remaining gas needs to be burned and purified in a direct-fired furnace. The combustion temperature exceeds 1000℃ to meet the waste gas emission standards, thus avoiding direct emission and environmental pollution. Existing direct-fired furnaces, after purifying the waste gas through combustion, directly emit the high-temperature, compliant gas. This high-temperature gas contains a large amount of heat energy, and direct emission results in high heat loss and low energy utilization. Utility Model Content

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a steam pyrolysis furnace exhaust gas treatment mechanism that purifies the exhaust gas through combustion, and the purified gas enters a heat exchanger to heat the air, thereby reducing heat loss and improving energy utilization.

[0005] This utility model provides a waste gas treatment mechanism for a steam pyrolysis furnace, including a gas supply pipe, a direct-fired furnace, a heat exchanger, an oxygen supplementation air fan, and an exhaust stack;

[0006] The direct-fired furnace includes a waste gas inlet, an air inlet, and a gas outlet, and an ignition mechanism is provided inside the direct-fired furnace.

[0007] The heat exchanger includes a refrigerant inlet, a refrigerant outlet, a heat medium inlet, and a heat medium outlet. The heat exchanger is provided with a first channel and a second channel. The two ends of the first channel are respectively connected to the refrigerant inlet and the refrigerant outlet, and the two ends of the second channel are respectively connected to the heat medium inlet and the heat medium outlet.

[0008] The exhaust gas inlet is connected to the gas supply pipe, and the gas supply pipe is used to transport the exhaust gas to be treated into the direct-fired furnace.

[0009] The air inlet is connected to the refrigerant outlet, and the refrigerant inlet is connected to the oxygen supplementation air fan. The oxygen supplementation air fan is used to transport external air through the first channel and into the direct-fired furnace.

[0010] The air outlet is connected to the heat medium inlet, and the heat medium outlet is connected to the exhaust stack. The purified waste gas flows through the second channel and is discharged through the exhaust stack.

[0011] Outside air and purified gas flow and exchange heat in the first and second channels, causing the air temperature to rise.

[0012] Furthermore, the oxygen-supplementing air fan is connected to the refrigerant inlet via a first air intake pipe, and the refrigerant outlet is connected to the air inlet via a second air intake pipe, with a temperature indicator installed on the second air intake pipe.

[0013] Furthermore, the direct-fired furnace is connected to a temperature measuring instrument for detecting the internal combustion temperature.

[0014] Furthermore, a pressure gauge and a safety valve are installed on the air supply pipe.

[0015] Furthermore, a flame arrester is also installed on the gas supply pipe.

[0016] Furthermore, an exhaust pipe is connected to the gas supply pipe between the flame arrester and the direct-fired furnace, and a rupture disc is provided at the connection between the exhaust pipe and the gas supply pipe.

[0017] Compared with the prior art, the beneficial effects of this utility model are:

[0018] This invention uses a gas supply pipe to transport the exhaust gas after passing through the condenser into a direct-fired furnace. An oxygen-supplementing air fan is used to supply external air into the furnace. The air mixes with the exhaust gas to form a combustible gas, which is then ignited by an ignition mechanism. This combustion process purifies the exhaust gas, preventing direct emissions that could pollute the environment. The purified gas then enters the first channel of a heat exchanger, while the oxygen-supplementing air fan supplies external air to the second channel. The external air and the purified gas exchange heat within the heat exchanger, raising the air temperature and preventing direct emissions of high-temperature gas, thus reducing heat loss and improving energy efficiency. Furthermore, the preheated air accelerates the combustion reaction within the furnace, promoting complete combustion of the exhaust gas.

[0019] It should be understood that the description in this utility model description section is not intended to limit the key or essential features of the embodiments of this utility model, nor is it intended to restrict the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0020] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] The following are labeled in the diagram: 1. Gas supply pipe; 2. Direct-fired furnace; 3. Heat exchanger; 4. Oxygen supplement air fan; 5. Exhaust stack; 6. First air inlet pipe; 7. Second air inlet pipe; 8. Temperature indicator; 9. Temperature measuring instrument; 10. Pressure gauge; 11. Safety valve; 12. Flame arrester; 13. Exhaust pipe; 14. Rupture disc;

[0023] 201. Exhaust gas inlet; 202. Air inlet; 203. Air outlet; 204. Ignition mechanism;

[0024] 301. Refrigerant import; 302. Refrigerant export; 303. Heat medium import; 304. Heat medium export; 2011. Nozzle. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the relevant invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0026] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] Please refer to Figure 1 The present invention provides a steam pyrolysis furnace exhaust gas treatment mechanism, including an air supply pipe 1, a direct-fired furnace 2, a heat exchanger 3, an oxygen supplementation air fan 4, and an exhaust pipe 5;

[0028] The direct-fired furnace 2 includes a waste gas inlet 201, an air inlet 202, and a gas outlet 203. An ignition mechanism 204 is installed inside the direct-fired furnace 201. Specifically, the direct-fired furnace 2 is a commercially available direct-fired waste gas oxidation incinerator. The waste gas inlet 201 of the direct-fired furnace 2 is equipped with a nozzle 2011, through which the waste gas is ejected. External air enters from the air inlet 202 and mixes with the waste gas to form a combustible gas. The ignition mechanism 204 includes an ignition plug, an ignition coil, and an ignition controller. When the mixed gas reaches a certain concentration, the ignition mechanism 204 will generate a spark to ignite the mixed gas for combustion.

[0029] The heat exchanger 3 includes a refrigerant inlet 301, a refrigerant outlet 302, a heat medium inlet 303, and a heat medium outlet 304. The heat exchanger 3 is provided with a first channel and a second channel. The two ends of the first channel are connected to the refrigerant inlet 301 and the refrigerant outlet 302, respectively, and the two ends of the second channel are connected to the heat medium inlet 303 and the heat medium outlet 304, respectively. Specifically, the heat exchanger 3 is a commercially available dual-channel heat exchanger, such as a shell-and-tube heat exchanger.

[0030] The exhaust gas inlet 201 is connected to the gas supply pipe 1, which is used to transport the exhaust gas to be treated into the direct-fired furnace 2. Specifically, one end of the gas supply pipe 1 is connected to the external condenser, and the other end is connected to the exhaust gas inlet 201, which is used to transport the remaining exhaust gas after passing through the condenser into the direct-fired furnace 2.

[0031] Air inlet 202 is connected to refrigerant outlet 302, and refrigerant inlet 301 is connected to oxygen supplementation air fan 4. Oxygen supplementation air fan 4 is used to transport external air through the first channel into the direct-fired furnace 2.

[0032] The air outlet 203 is connected to the heat medium inlet 303, and the heat medium outlet 304 is connected to the exhaust pipe 5. The purified gas flows through the second channel and is discharged through the exhaust pipe 5.

[0033] Outside air and purified gas flow and exchange heat in the first and second channels, causing the air temperature to rise.

[0034] In this embodiment, the gas supply pipe 1 delivers the remaining waste gas after passing through the condenser to the waste gas inlet 201 of the direct-fired furnace 2. The waste gas is sprayed out through the nozzle 2011, and the oxygen-supplementing air fan 4 inputs external air into the first channel of the heat exchanger 3. After flowing in the first channel, the air also enters the direct-fired furnace 2. The air and waste gas mix to form combustible gas, which is ignited by the ignition mechanism to carry out a combustion reaction. The waste gas is purified during the combustion process. When the combustion temperature reaches above 1000℃, it meets the gas emission standards. The purified gas is discharged from the outlet 203 into the second channel of the heat exchanger 3. After flowing in the second channel, it is discharged through the exhaust pipe 5, avoiding direct emission of waste gas and pollution of the environment. In this embodiment, the external air and the purified gas exchange heat inside the heat exchanger, causing the air temperature to rise, avoiding direct emission of the purified high-temperature gas, reducing heat loss, and improving energy utilization. Moreover, the preheated air can accelerate the combustion reaction in the direct-fired furnace and promote the complete combustion of waste gas.

[0035] In a preferred embodiment, such as Figure 1As shown, the oxygen-supplementing air fan 4 is connected to the refrigerant inlet 301 via the first air intake pipe 6, and the refrigerant outlet 302 is connected to the air inlet 202 via the second air intake pipe 7. A temperature indicator 8 is installed on the second air intake pipe 7. Specifically, the temperature indicator 8 can be used to visually monitor the air temperature inside the second air intake pipe 7, thereby determining whether the outside air is being heated.

[0036] In a preferred embodiment, such as Figure 1 As shown, the direct-fired furnace 2 is connected to a temperature measuring instrument 9 for detecting the internal combustion temperature.

[0037] Specifically, the measuring probe of the temperature measuring instrument 9 extends into the direct-fired furnace 2 to detect the combustion temperature inside the furnace 2. A valve is installed at the gas outlet 203 of the direct-fired furnace 2. Both the valve and the temperature measuring instrument 9 are connected to the control system. When the temperature measuring instrument 9 detects a combustion temperature greater than 1000℃, it indicates that the exhaust gas purification is complete. The control system then controls the valve to open, and the purified gas is discharged. When the temperature measuring instrument 9 detects a combustion temperature less than or equal to 1000℃, it indicates that the exhaust gas purification has not yet met the standard. The control system then controls the valve to close, and the exhaust gas continues to burn and be purified inside the direct-fired furnace 2 without being discharged.

[0038] In a preferred embodiment, such as Figure 1 As shown, a pressure gauge 10 and a safety valve 11 are installed on the air supply pipe 1.

[0039] Specifically, the pressure gauge 10 monitors the gas pressure in the gas supply pipe 1 in real time, allowing staff to promptly understand the gas pressure status within the pipe. Multiple safety valves 11 can be installed; when the gas pressure in the gas supply pipe 1 is lower than the pressure in the direct-fired furnace 2, the safety valve 11 automatically closes to prevent gas from the direct-fired furnace 2 from flowing into the gas supply pipe 1, thus preventing backfire in the furnace and improving safety.

[0040] In a preferred embodiment, such as Figure 1 As shown, a flame arrester 12 is also installed on the gas supply pipe 1.

[0041] Specifically, the flame arrester 12 utilizes special structures such as metal mesh and corrugated plates to extinguish the flame as it passes through due to a sudden increase in heat loss. Under normal circumstances, the flame arrester 12 will not affect the normal transport of exhaust gas and can ensure that the exhaust gas enters the direct-fired furnace 2 smoothly for combustion and purification. When a backfire occurs in the direct-fired furnace 2, that is, when the flame burns along the gas supply pipe 1 towards the exhaust gas source, the flame arrester 12 can effectively prevent the spread of the flame and improve safety.

[0042] In a preferred embodiment, such as Figure 1 As shown, an exhaust pipe 13 is connected to the gas supply pipe 1 between the flame arrester 12 and the direct-fired furnace 2, and a rupture disc 14 is provided at the connection between the exhaust pipe 13 and the gas supply pipe 1.

[0043] Specifically, when the pressure inside the air supply pipe 1 rises sharply due to abnormal reasons and exceeds the set pressure that the rupture disc 14 can withstand, the rupture disc 14 will rupture instantly, quickly releasing the high-pressure gas inside the air supply pipe 1 into the exhaust pipe 13, thereby preventing serious accidents such as rupture and explosion of the air supply pipe 1 due to overpressure.

[0044] In the description of this specification, the terms "connection," "installation," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0045] In the description of this specification, the terms "one embodiment," "some embodiments," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0046] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A waste gas treatment mechanism for a steam pyrolysis furnace, characterized in that, It includes a gas supply pipe (1), a direct-fired furnace (2), a heat exchanger (3), an oxygen supplementation air fan (4), and an exhaust stack (5); The direct-fired furnace (2) includes a waste gas inlet (201), an air inlet (202) and an air outlet (203), and an ignition mechanism (204) is provided inside the direct-fired furnace (2); The heat exchanger (3) includes a refrigerant inlet (301), a refrigerant outlet (302), a heat medium inlet (303), and a heat medium outlet (304). The heat exchanger (3) is provided with a first channel and a second channel. The two ends of the first channel are respectively connected to the refrigerant inlet (301) and the refrigerant outlet (302), and the two ends of the second channel are respectively connected to the heat medium inlet (303) and the heat medium outlet (304). The exhaust gas inlet (201) is connected to the gas supply pipe (1), and the gas supply pipe (1) is used to transport the exhaust gas to be treated into the direct-fired furnace (2); The air inlet (202) is connected to the refrigerant outlet (302), and the refrigerant inlet (301) is connected to the oxygen supplement air fan (4). The oxygen supplement air fan (4) is used to transport external air through the first channel and into the direct-fired furnace (2). The air outlet (203) is connected to the heat medium inlet (303), and the heat medium outlet (304) is connected to the exhaust pipe (5). The purified gas flows through the second channel and is discharged through the exhaust pipe (5). Outside air and purified gas flow and exchange heat in the first and second channels, causing the air temperature to rise.

2. The steam pyrolysis furnace exhaust gas treatment mechanism according to claim 1, characterized in that, The oxygen supplement air fan (4) is connected to the refrigerant inlet (301) through the first air inlet pipe (6), and the refrigerant outlet (302) is connected to the air inlet (202) through the second air inlet pipe (7). A temperature indicator (8) is installed on the second air inlet pipe (7).

3. The steam pyrolysis furnace exhaust gas treatment mechanism according to claim 1, characterized in that, The direct-fired furnace (2) is connected to a temperature measuring instrument (9) for detecting the internal combustion temperature.

4. The steam pyrolysis furnace exhaust gas treatment mechanism according to claim 1, characterized in that, A pressure gauge (10) and a safety valve (11) are installed on the air supply pipe (1).

5. The steam pyrolysis furnace exhaust gas treatment mechanism according to claim 1, characterized in that, A flame arrester (12) is also provided on the gas supply pipe (1).

6. The steam pyrolysis furnace exhaust gas treatment mechanism according to claim 5, characterized in that, An exhaust pipe (13) is connected to the gas supply pipe (1) between the flame arrester and the direct-fired furnace (2), and a rupture disc (14) is provided at the connection between the exhaust pipe and the gas supply pipe (1).

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