Method and system for removing waste gas from chimney in emergency state of direct-fired incinerator

Abstract

The invention relates to the technical field of direct-fired incinerators, in particular to a method and system for removing waste gas of a direct-fired incinerator from a chimney in an emergency state. Comprising an incinerator, a waste gas fan, a combined combustor, an incinerator aftertreatment system, a bypass pipeline, an induced draft fan and a chimney, when a combustible alarm instrument LEL monitors that the concentration is 25% or below, the incinerator operates normally in an incineration mode, and when the combustible alarm instrument LEL monitors that the concentration is 25% or above, an interlocked waste gas pipeline switching valve is closed, an interlocked bypass pipeline switching valve is opened, and the combined combustor operates normally; the induced draft fan keeps running, waste gas is led to the chimney through the bypass pipeline and the induced draft fan, high-altitude emission is conducted through the chimney, when the combustible alarm instrument LEL monitors that the concentration is recovered to be lower than 25% and before it is manually confirmed that a bypass pipeline switching valve is closed, residual high-concentration combustible mixed gas in the bypass pipeline is exhausted through running of the induced draft fan, and at the moment, emergency emission is completed; high-concentration waste gas is prevented from remaining in the bypass pipeline, the combustible explosion risk is avoided, and potential safety hazards of life and property of personnel are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of direct-fired incinerators, and in particular to a method and system for removing waste gas from a chimney of a direct-fired incinerator in an emergency state. Background Art

[0002] The direct-fired incinerator is an efficient waste gas treatment and environmental protection equipment with a combustion temperature of up to 1100 degrees Celsius. It oxidizes organic pollutants into harmless substances such as water and carbon dioxide by mixing and burning the waste gas with the fuel in the combustion chamber. The high-temperature combustion gas generated by the combustion directly contacts the waste gas, so that it can achieve the effect of complete combustion and degradation. It is suitable for treating a variety of waste gas mixtures, generally including combustible gases, ethylene dichloride, ethylene oxide and other combustible gases.

[0003] During the process of incinerating waste gas in a direct-fired incinerator, emergency situations may occur. For example, the waste gas concentration of the upstream production equipment is too high and does not meet the conditions for incineration in the incinerator, or the incineration system of the incinerator itself has abnormal conditions and cannot be incinerated normally. Therefore, under the premise of ensuring safety, the incineration system will automatically switch the waste gas to be discharged directly to the chimney at high altitude to avoid waste gas with combustible explosion risks entering the incineration system and forming an explosion, thereby ensuring the safety of personnel and property.

[0004] However, in an emergency state, the existing direct-fired incinerators generally use the combustible and toxic alarm LEL high-limit interlock on the incinerator inlet switch valve on the upstream exhaust gas main pipe of the incinerator system to close the incinerator inlet switch valve, and interlock the bypass emission inlet switch valve to open, so that the upstream exhaust gas is switched to the bypass pipe and sent to the chimney through the bypass pipe for emergency discharge. In this way, after the bypass pipe is discharged, there is no induced draft fan on the side of the pipe close to the chimney, which results in residual combustible exhaust gas with a high LEL limit in the pipe after the bypass pipe is discharged. This exhaust gas is prone to produce combustible explosion risks in the pipe, posing a serious safety hazard. Summary of the invention

[0005] The purpose of the present invention is to provide a method and system for removing waste gas from a direct-fired incinerator to a chimney in an emergency state, so as to solve the problem that during the use of the traditional direct-fired incinerator waste gas removal chimney system in an emergency state, combustible waste gas with a high LEL limit will always remain in the pipeline, and this waste gas is prone to produce combustible explosion risks in the pipeline, posing serious safety hazards.

[0006] To achieve the above-mentioned purpose, the present invention provides a system for removing waste gas from a direct-fired incinerator to a chimney in an emergency state, the system for removing waste gas from a direct-fired incinerator to a chimney in an emergency state comprises an incinerator, an exhaust gas fan, a combined burner, an incinerator post-processing system, a bypass pipe, an induced draft fan and a chimney, the output end of the exhaust gas fan is connected to an upstream mixed exhaust gas source through a pipe, the output end of the exhaust gas fan is connected to the incinerator through a pipe, the combined burner is arranged at one end of the incinerator close to the exhaust gas fan, the incinerator post-processing system is connected to one end of the incinerator away from the combined burner through a pipe, the input end of the induced draft fan is connected to the incinerator post-processing system through a pipe, and the output end of the induced draft fan is connected to the chimney through a pipe;

[0007] A boundary butterfly valve, a flammable alarm LEL and an exhaust pipe switch valve are sequentially arranged on the pipe connecting the upstream mixed exhaust gas source and the input end of the exhaust gas fan; an incinerator flame arrester is arranged between the output end of the exhaust gas fan and the pipe connected to the incinerator; the opening position of the bypass pipe is arranged on the pipe between the flammable alarm LEL and the exhaust pipe switch valve; the outlet position of the bypass pipe is arranged on the pipe between the incinerator post-treatment system and the input end of the induced draft fan; and the bypass pipe switch valve is sequentially arranged on the bypass pipe.

[0008] Among them, a first manual exhaust pipe valve and a second manual exhaust pipe valve are respectively arranged on both sides of the exhaust pipe switch valve, the first manual exhaust pipe valve is located between the exhaust pipe switch valve and the flammable alarm LEL, and the second manual exhaust pipe valve is located between the exhaust pipe switch valve and the input end of the exhaust blower.

[0009] Among them, a first bypass pipe manual valve and a second bypass pipe manual valve are respectively arranged on both sides of the bypass pipe switch valve, the first bypass pipe manual valve is located between the bypass pipe switch valve and the flammable alarm LEL, and the second bypass pipe manual valve is located between the bypass pipe switch valve and the input end of the exhaust gas fan.

[0010] Among them, the shortest distance between the flammable alarm LEL and the exhaust pipe switch valve is 100 meters.

[0011] Among them, the number of the flammable alarm LEL is not less than 2 sets.

[0012] Among them, the opening position of the bypass pipe is set between the flammable alarm LEL and the first manual valve of the exhaust gas pipe.

[0013] The present invention also provides a method for removing waste gas from a direct-fired incinerator to a chimney in an emergency state, which is applied to the system for removing waste gas from a direct-fired incinerator to a chimney in an emergency state as described above, and comprises the following steps:

[0014] The mixed exhaust gas containing combustible gas generated by the upstream mixed exhaust gas source is introduced into the incinerator through the exhaust gas blower for incineration treatment;

[0015] The high-temperature flue gas after incineration is post-processed by the incinerator post-processing system and then transported to the chimney for discharge under the action of the induced draft fan;

[0016] During the incineration process of the mixed waste gas containing combustible gas, the combustible alarm LEL is used to monitor the mixed waste gas containing combustible gas in real time;

[0017] When the combustible alarm LEL monitors that the concentration is below 25%, the incinerator is burning normally, and the exhaust gas enters the incinerator through the exhaust gas fan for full combustion, and then is treated by the downstream incinerator post-treatment system, and then is led to the chimney through the induced draft fan for high-altitude emission that meets the standards;

[0018] When the flammable alarm LEL monitors a concentration of 25% or above, the exhaust pipe switch valve is interlocked to close, the bypass pipe switch valve is interlocked to open, the induced draft fan is kept running, and the exhaust gas is led to the chimney through the bypass pipe and the induced draft fan, and is directly discharged into the air through the chimney;

[0019] When the flammable alarm LEL monitors that the concentration has recovered to below 25%, before manually confirming the closing of the bypass pipeline switch valve, the high-concentration flammable mixture remaining in the bypass pipeline is exhausted by the operation of the induced draft fan, and the emergency discharge is completed at this time.

[0020] The present invention discloses a method and system for removing waste gas from a chimney in an emergency state of a direct-fired incinerator, comprising an incinerator, an exhaust gas fan, a combined burner, an incinerator post-treatment system, a bypass pipe, an induced draft fan and a chimney. In the incineration treatment process of mixed exhaust gas containing combustible gas, the combustible alarm LEL is used to monitor the mixed exhaust gas containing combustible gas in real time. When the combustible alarm LEL monitors that the concentration is below 25%, the incinerator is burning normally, and the exhaust gas enters the incinerator through the exhaust gas fan for full combustion. After being treated by the downstream post-treatment system of the incinerator, the exhaust gas is led to the chimney through the induced draft fan for high-altitude emission that meets the standards. When the combustible alarm LEL monitors that the concentration is below 25%, the incinerator is burning normally. When the combustible alarm LEL monitors a concentration of 25% and above, the exhaust pipe switch valve is interlocked to be closed, the bypass pipe switch valve is interlocked to be opened, the induced draft fan keeps running, and the exhaust gas is led to the chimney through the bypass pipe and the induced draft fan, and directly discharged into the air through the chimney. When the combustible alarm LEL monitors that the concentration has recovered to below 25%, before manually confirming the closing of the bypass pipe switch valve, the induced draft fan is operated to exhaust the high-concentration combustible mixture remaining in the bypass pipe. At this time, the emergency discharge is completed to avoid high-concentration exhaust gas remaining in the bypass pipe, the risk of combustible explosion, and reduce the safety hazard of life and property. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the structure of the system for removing waste gas from a chimney in an emergency state of a direct-fired incinerator provided by the present invention.

[0023] Figure 2 It is a flow chart of the steps of the method for removing waste gas from a chimney in an emergency state of a direct-fired incinerator provided by the present invention.

[0024] 1-upstream mixed exhaust gas, 2-exhaust gas fan, 3-combination burner, 4-incinerator, 5-induced draft fan, 6-chimney, 7-boundary butterfly valve, 8-bypass pipe first hand valve, 9-exhaust pipe first hand valve, 10-bypass pipe switch valve, 11-exhaust pipe switch valve, 12-bypass pipe second hand valve, 13-exhaust pipe second hand valve, 14-incinerator flame arrester, 15-flammable alarm LEL, 16-incinerator post-treatment system, 17-bypass pipe. DETAILED DESCRIPTION

[0025] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0026] See also Figure 1 The present invention provides a system for removing waste gas from a direct-fired incinerator to a chimney 6 in an emergency state, wherein the system for removing waste gas from a direct-fired incinerator to a chimney 6 in an emergency state comprises an incinerator 4, an exhaust gas fan 2, a combined burner 3, an incinerator post-treatment system 16, a bypass pipe 17, an induced draft fan 5 and a chimney 6, wherein the output end of the exhaust gas fan 2 is connected to an upstream mixed exhaust gas source 1 through a pipe, the output end of the exhaust gas fan 2 is connected to the incinerator 4 through a pipe, the combined burner 3 is arranged at one end of the incinerator 4 close to the exhaust gas fan 2, the incinerator 4 is connected to the incinerator post-treatment system 16 through a pipe at one end away from the combined burner 3, the input end of the induced draft fan 5 is connected to the incinerator post-treatment system 16 through a pipe, and the output end of the induced draft fan 5 is connected to the chimney 6 through a pipe;

[0027] The pipeline connecting the upstream mixed exhaust gas source 1 and the input end of the exhaust gas fan 2 is provided with a boundary butterfly valve 7, a flammable alarm LEL15 and an exhaust gas pipeline switch valve 11 in sequence, an incinerator flame arrester 14 is provided between the output end of the exhaust gas fan 2 and the pipeline connected to the incinerator 4, the opening position of the bypass pipeline 17 is provided on the pipeline between the flammable alarm LEL15 and the exhaust gas pipeline switch valve 11, the outlet position of the bypass pipeline 17 is provided on the pipeline between the incinerator post-treatment system 16 and the input end of the induced draft fan 5, and the bypass pipeline switch valve 10 is provided on the bypass pipeline 17 in sequence.

[0028] In this embodiment, during the incineration process of the mixed exhaust gas containing combustible gas, the combustible alarm device LEL15 is used to monitor the mixed exhaust gas containing combustible gas in real time. When the combustible alarm device LEL15 monitors that the concentration is below 25%, the incinerator 4 is burning normally, and the exhaust gas enters the incinerator 4 through the exhaust gas fan 2 for full combustion. After being processed by the downstream incinerator post-treatment system 16, it is led to the chimney 6 through the induced draft fan 5 for high-altitude emission. When the combustible alarm device LEL15 monitors that the concentration is 25% or above, the exhaust pipe opening is interlocked. The shut-off valve 11 is closed, the interlocked bypass duct switch valve 10 is opened, the induced draft fan 5 keeps running, the exhaust gas is led to the chimney 6 through the bypass duct 17 and the induced draft fan 5, and is directly discharged into the air through the chimney 6. When the flammable alarm LEL15 detects that the concentration has recovered to below 25%, before manually confirming the closing of the bypass duct switch valve 10, the high-concentration flammable mixture remaining in the bypass duct 17 is exhausted through the operation of the induced draft fan 5. At this time, the emergency discharge is completed to avoid the high-concentration exhaust gas remaining in the bypass duct 17, the risk of flammable explosion, and reduce the safety hazard of life and property.

[0029] Furthermore, a first exhaust pipe manual valve 9 and a second exhaust pipe manual valve 13 are respectively provided on both sides of the exhaust pipe switch valve 11. The first exhaust pipe manual valve 9 is located between the exhaust pipe switch valve 11 and the flammable alarm LEL15, and the second exhaust pipe manual valve 13 is located between the exhaust pipe switch valve 11 and the input end of the exhaust gas fan 2.

[0030] Furthermore, a bypass pipe first manual valve 10 and a bypass pipe second manual valve 12 are respectively provided on both sides of the bypass pipe switch valve 10. The bypass pipe first manual valve 10 is located between the bypass pipe switch valve 10 and the flammable alarm LEL15, and the bypass pipe second manual valve 12 is located between the bypass pipe switch valve 10 and the input end of the exhaust gas fan 2.

[0031] Furthermore, the shortest distance between the flammable alarm LEL15 and the exhaust pipe switch valve 11 is 100 meters.

[0032] Furthermore, the number of the flammable alarm LEL15 is not less than 2 sets.

[0033] Furthermore, the opening position of the bypass pipe 17 is set between the flammable alarm LEL15 and the first manual valve 9 of the exhaust pipe.

[0034] See also Figure 2The present invention also provides a method for removing waste gas from a direct-fired incinerator to a chimney 6 in an emergency state, which is applied to the system for removing waste gas from a direct-fired incinerator to a chimney 6 in an emergency state as claimed in claim 1, and is characterized in that it comprises the following steps:

[0035] S1: The mixed exhaust gas containing combustible gas generated by the upstream mixed exhaust gas source 1 is introduced into the incinerator 4 through the exhaust gas blower 2 for incineration treatment;

[0036] S2: After the high-temperature flue gas after incineration is post-processed by the incinerator post-processing system 16, it is transported to the chimney 6 for discharge under the action of the induced draft fan 5;

[0037] S3: During the incineration process of the mixed waste gas containing combustible gas, the combustible alarm device LEL15 is used to monitor the mixed waste gas containing combustible gas in real time;

[0038] S4: When the combustible alarm LEL15 monitors that the concentration is below 25%, the incinerator 4 is burning normally, and the exhaust gas enters the incinerator 4 through the exhaust gas fan 2 for full combustion, and then is treated by the downstream incinerator post-treatment system 16, and then is led to the chimney 6 through the induced draft fan 5 for high-altitude emission that meets the standards;

[0039] S5: When the flammable alarm LEL15 detects that the concentration is 25% or above, the exhaust pipe switch valve 11 is interlocked to be closed, the bypass pipe switch valve 10 is interlocked to be opened, the induced draft fan 5 keeps running, and the exhaust gas is led to the chimney 6 through the bypass pipe 17 and the induced draft fan 5, and is directly discharged into the air through the chimney 6;

[0040] S6: When the flammable alarm LEL15 detects that the concentration has recovered to below 25%, before manually confirming the closing of the bypass pipe switch valve 10, the high-concentration flammable mixture remaining in the bypass pipe 17 is exhausted by the operation of the induced draft fan 5, and the emergency discharge is completed at this time.

[0041] In this embodiment, the mixed exhaust gas containing combustible gas generated by the upstream mixed exhaust gas source 1 is introduced into the incinerator 4 through the exhaust gas fan 2 for incineration treatment. The high-temperature flue gas after incineration is post-treated by the incinerator post-treatment system 16 (the high-temperature flue gas after incineration is passed through the boiler and the flue gas heat exchanger for waste heat utilization, and then cooled by the quenching tower, and the rapid cooling method is used to suppress the production of dioxins. The flue gas after rapid cooling is passed through the alkali washing tower for alkaline washing and acid removal. The exhausted flue gas is heated by the heat exchanger and the duct burner and enters the subsequent SCR denitrification device. The purified flue gas is further utilized for waste heat by the air preheater). Under the action of the induced draft fan 5, it is transported to the chimney 6 for discharge. In the incineration treatment process of the mixed exhaust gas containing combustible gas, the combustible alarm device LEL15 is used to monitor the mixed exhaust gas containing combustible gas in real time. When the combustible alarm device LEL15 detects that the concentration is below 25%, the incinerator 4 is burning normally. During operation, the exhaust gas enters the incinerator 4 through the exhaust gas fan 2 for full combustion, and then is treated by the downstream incinerator post-treatment system 16, and then is led to the chimney 6 through the induced draft fan 5 for high-altitude emission that meets the standards. When the combustible alarm device LEL15 monitors that the concentration is 25% or above, the exhaust pipe switch valve 11 is interlocked to be closed, and the bypass pipe switch valve 10 is interlocked to be opened. The induced draft fan 5 keeps running, and the exhaust gas is led to the chimney 6 through the bypass pipe 17 and the induced draft fan 5, and is directly discharged into the air through the chimney 6. When the combustible alarm device LEL15 monitors that the concentration is restored to below 25%, before manually confirming the closing of the bypass pipe switch valve 10, the high-concentration combustible mixture remaining in the bypass pipe 17 is exhausted through the operation of the induced draft fan 5. At this time, the emergency emission is completed, avoiding the high-concentration exhaust gas remaining in the bypass pipe 17, the risk of combustible explosion, and reducing the safety hazards of life and property.

[0042] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A system for removing waste gas from a direct-fired incinerator to a chimney in an emergency state, characterized in that: It includes an incinerator, an exhaust gas fan, a combined burner, an incinerator post-processing system, a bypass pipe, an induced draft fan and a chimney, wherein the output end of the exhaust gas fan is connected to an upstream mixed exhaust gas source through a pipe, the output end of the exhaust gas fan is connected to the incinerator through a pipe, the combined burner is arranged at one end of the incinerator close to the exhaust gas fan, the end of the incinerator away from the combined burner is connected to the incinerator post-processing system through a pipe, the input end of the induced draft fan is connected to the incinerator post-processing system through a pipe, and the output end of the induced draft fan is connected to the chimney through a pipe; A boundary butterfly valve, a flammable alarm LEL and an exhaust pipe switch valve are sequentially arranged on the pipe connecting the upstream mixed exhaust gas source and the input end of the exhaust gas fan; an incinerator flame arrester is arranged between the output end of the exhaust gas fan and the pipe connected to the incinerator; the opening position of the bypass pipe is arranged on the pipe between the flammable alarm LEL and the exhaust pipe switch valve; the outlet position of the bypass pipe is arranged on the pipe between the incinerator post-treatment system and the input end of the induced draft fan; and the bypass pipe switch valve is sequentially arranged on the bypass pipe.

2. The system for removing waste gas from a direct-fired incinerator to a chimney in an emergency state as claimed in claim 1, characterized in that: A first exhaust pipe manual valve and a second exhaust pipe manual valve are respectively arranged on both sides of the exhaust pipe switch valve. The first exhaust pipe manual valve is located between the exhaust pipe switch valve and the flammable alarm LEL, and the second exhaust pipe manual valve is located between the exhaust pipe switch valve and the input end of the exhaust blower.

3. The system for removing waste gas from a direct-fired incinerator to a chimney in an emergency state as claimed in claim 2, characterized in that: A first bypass duct manual valve and a second bypass duct manual valve are respectively arranged on both sides of the bypass duct switch valve. The first bypass duct manual valve is located between the bypass duct switch valve and the flammable alarm LEL, and the second bypass duct manual valve is located between the bypass duct switch valve and the input end of the exhaust gas fan.

4. The system for removing waste gas from a direct-fired incinerator to a chimney in an emergency state as claimed in claim 3, characterized in that: The shortest distance between the flammable alarm LEL and the exhaust pipe switch valve is 100 meters.

5. The system for removing waste gas from a direct-fired incinerator to a chimney in an emergency state as claimed in claim 4, characterized in that: The number of the said flammable alarm LEL shall not be less than 2 sets.

6. The system for removing waste gas from a direct-fired incinerator to a chimney in an emergency state as claimed in claim 5, characterized in that: The opening position of the bypass pipe is arranged between the flammable alarm LEL and the first manual valve of the exhaust pipe.

7. A method for removing waste gas from a direct-fired incinerator in an emergency state to a chimney, applied to the system for removing waste gas from a direct-fired incinerator in an emergency state as claimed in claim 1, characterized in that: The steps include: The mixed exhaust gas containing combustible gas generated by the upstream mixed exhaust gas source is introduced into the incinerator through the exhaust gas blower for incineration treatment; The high-temperature flue gas after incineration is post-processed by the incinerator post-processing system and then transported to the chimney for discharge under the action of the induced draft fan; During the incineration process of the mixed waste gas containing combustible gas, the combustible alarm LEL is used to monitor the mixed waste gas containing combustible gas in real time; When the combustible alarm LEL monitors that the concentration is below 25%, the incinerator is burning normally, and the exhaust gas enters the incinerator through the exhaust gas fan for full combustion, and then is treated by the downstream incinerator post-treatment system, and then is led to the chimney through the induced draft fan for high-altitude emission that meets the standards; When the flammable alarm LEL monitors a concentration of 25% or above, the exhaust pipe switch valve is interlocked to close, the bypass pipe switch valve is interlocked to open, the induced draft fan is kept running, and the exhaust gas is led to the chimney through the bypass pipe and the induced draft fan, and is directly discharged into the air through the chimney; When the flammable alarm LEL monitors that the concentration has recovered to below 25%, before manually confirming the closing of the bypass pipeline switch valve, the high-concentration flammable mixture remaining in the bypass pipeline is exhausted by the operation of the induced draft fan, and the emergency discharge is completed at this time.

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