Method and system for exhaust gas chimney in emergency state of direct-fired incinerator

Abstract

The present application relates to direct-fired incinerator technical field, specifically to a kind of direct-fired incinerator waste gas chimney method and system under emergency state;Including incinerator, waste gas fan, combined combustor, incinerator post-processing system, bypass pipeline, induced draft fan and chimney, when combustible alarm instrument LEL monitors concentration below 25%, incinerator normal incineration operation, when combustible alarm instrument LEL monitors concentration at 25% and above 25%, interlock waste gas pipeline switch valve is closed, interlock bypass pipeline switch valve is opened, induced draft fan keeps running, waste gas is guided to chimney by bypass pipeline and induced draft fan, high-altitude discharge is carried out by chimney, when combustible alarm instrument LEL monitors concentration recovers to below 25%, manually confirm to close bypass pipeline switch valve before, by the operation of induced draft fan, exhaust the residual high-concentration combustible mixture in bypass pipeline, at this time, emergency discharge is completed, avoid high-concentration waste gas to remain in bypass pipeline, combustible explosion risk occurs, reduce the security risk of personnel life and property.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of direct-fired incinerator, and particularly relates to a method and system for waste gas going to chimney in emergency state of direct-fired incinerator. BACKGROUND

[0002] The direct-fired incinerator is a kind of high-efficiency waste gas treatment environmental protection equipment, the combustion temperature is as high as 1100 degrees Celsius, the organic pollutants are oxidized into harmless substances such as water and carbon dioxide by mixing and burning the waste gas together with the fuel in the combustion chamber. The high-temperature combustion gas generated by combustion directly contacts the waste gas, so that the complete combustion and degradation effect is achieved, and the direct-fired incinerator is suitable for treating various waste gas mixed gas, generally containing combustible gas, dichloroethane, ethylene oxide and other combustible gas.

[0003] During the incineration of waste gas by the direct-fired incinerator, emergency state may exist, for example, the upstream production device waste gas concentration is too high, which does not meet the incineration condition of the incinerator, or abnormal situation occurs in the incineration system of the incinerator, so that the incineration system automatically switches the waste gas to be directly discharged to the chimney at high altitude under the premise of ensuring safety, so as to avoid the waste gas with combustible and explosive risk entering the incineration system to form explosion, thereby ensuring the safety of personnel and property.

[0004] However, in the emergency state of the existing direct-fired incinerator, the combustible and toxic alarm instrument LEL high limit interlocking incinerator inlet valve on the upstream waste gas main pipe of the incinerator system is closed, and the interlocking bypass discharge inlet valve is opened, so that the upstream waste gas is switched to the bypass pipeline, and then the waste gas is sent to the chimney for emergency discharge. After the waste gas is discharged through the bypass pipeline, the combustible waste gas with LEL high limit is always left in the pipeline due to the absence of an air fan near the chimney on the side of the pipeline, so that the combustible waste gas is easy to cause combustible explosion risk in the pipeline, and there is a serious safety hazard. SUMMARY

[0005] The present application aims to provide a method and system for waste gas going to chimney in emergency state of direct-fired incinerator, which solves the problem that the combustible waste gas with LEL high limit is always left in the pipeline during the use of the waste gas going to chimney system in the emergency state of the traditional direct-fired incinerator, the combustible waste gas is easy to cause combustible explosion risk in the pipeline, and there is a serious safety hazard.

[0006] In order to achieve the above object, the present application provides a system for discharging waste gas to a chimney in an emergency state of a direct-fired incinerator, which comprises an incinerator, a waste gas fan, a combined burner, an incinerator post-processing system, a bypass pipeline, an induced draft fan and a chimney, the output end of the waste gas fan is connected with an upstream mixed waste gas source through a pipeline, the output end of the waste gas fan is connected with the incinerator through a pipeline, the end of the incinerator close to the waste gas fan is provided with the combined burner, the end of the incinerator away from the combined burner is connected with the incinerator post-processing system through a pipeline, the input end of the induced draft fan is connected with the incinerator post-processing system through a pipeline, and the output end of the induced draft fan is connected with the chimney through a pipeline.

[0007] A boundary butterfly valve, a combustible alarm instrument LEL and a waste gas pipeline switch valve are sequentially arranged on the pipeline connecting the upstream mixed waste gas source with the input end of the waste gas fan, a incinerator fire damper is arranged between the output end of the waste gas fan and the pipeline connecting with the incinerator, the opening position of the bypass pipeline is arranged on the pipeline between the combustible alarm instrument LEL and the waste gas pipeline switch valve, the outlet position of the bypass pipeline is arranged on the pipeline between the incinerator post-processing system and the input end of the induced draft fan, and a bypass pipeline switch valve is sequentially arranged on the bypass pipeline.

[0008] Wherein, the two sides of the waste gas pipeline switch valve are respectively provided with a waste gas pipeline first hand valve and a waste gas pipeline second hand valve, the waste gas pipeline first hand valve is located between the waste gas pipeline switch valve and the combustible alarm instrument LEL, and the waste gas pipeline second hand valve is located between the waste gas pipeline switch valve and the input end of the waste gas fan.

[0009] Wherein, the two sides of the bypass pipeline switch valve are respectively provided with a bypass pipeline first hand valve and a bypass pipeline second hand valve, the bypass pipeline first hand valve is located between the bypass pipeline switch valve and the combustible alarm instrument LEL, and the bypass pipeline second hand valve is located between the bypass pipeline switch valve and the input end of the waste gas fan.

[0010] Wherein, the shortest distance between the combustible alarm instrument LEL and the waste gas pipeline switch valve is 100 meters.

[0011] Wherein, the number of the combustible alarm instrument LEL is not less than 2 sets.

[0012] Wherein, the opening position of the bypass pipeline is arranged between the combustible alarm instrument LEL and the waste gas pipeline first hand valve.

[0013] The application further provides a method for discharging waste gas to a chimney in an emergency state of a direct combustion incinerator, which is applied to the system for discharging waste gas to a chimney in an emergency state of a direct combustion incinerator as described above and comprises the following steps.

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

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

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

[0017] When the combustible alarm instrument LEL monitors that the concentration is below 25%, the incinerator is normally incinerated, the waste gas is introduced into the incinerator by the waste gas fan for sufficient combustion, and then is treated by the post-treatment system of the incinerator downstream, and is introduced into the chimney by the induced draft fan for high-altitude discharge meeting the standard;

[0018] When the combustible alarm instrument LEL monitors that the concentration is 25% or above, the waste gas pipeline switch valve is closed, the bypass pipeline switch valve is opened, the induced draft fan keeps running, the waste gas is introduced into the chimney by the bypass pipeline and the induced draft fan, and is directly discharged through the chimney for high-altitude discharge;

[0019] When the combustible alarm instrument LEL monitors that the concentration returns to below 25%, the bypass pipeline switch valve is manually closed, the residual high-concentration combustible mixed gas in the bypass pipeline is exhausted by the running of the induced draft fan, and at this time, the emergency discharge is completed.

[0020] This invention discloses a method and system for direct-fired incinerator exhaust gas removal to a chimney under emergency conditions. The system includes an incinerator, an exhaust gas fan, a combined burner, an incinerator after-treatment system, a bypass pipe, an induced draft fan, and a chimney. During the incineration of a mixed exhaust gas containing combustible gas, a combustible gas alarm (LEL) is used to monitor the mixed exhaust gas in real time. When the LEL detects a concentration below 25%, the incinerator operates normally. The exhaust gas enters the incinerator through the exhaust gas fan for complete combustion. After further treatment by the downstream incinerator after-treatment system, the exhaust gas is led to the chimney by the induced draft fan for high-altitude emission to meet emission standards. When the LEL (Low-Concentration Flammable Gas Alarm) detects a concentration of 25% or higher, it interlocks the closure of the exhaust gas pipeline valve and the opening of the bypass pipeline valve. The induced draft fan continues to operate, and the exhaust gas is drawn through the bypass pipeline and the induced draft fan to the chimney for direct high-altitude discharge. When the LEL detects that the concentration has returned to below 25%, before manually confirming the closure of the bypass pipeline valve, the induced draft fan is used to extract the remaining highly concentrated flammable mixture in the bypass pipeline. At this point, the emergency discharge is complete, preventing the high-concentration exhaust gas from remaining in the bypass pipeline and posing a risk of flammable explosion, thus reducing the safety hazards to personnel and property. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0023] Figure 2 This is a flowchart illustrating the steps of the method for removing waste gas from a direct-fired incinerator to a chimney under emergency conditions, as provided by the present invention.

[0024] 1-Upstream mixed waste gas, 2-Waste gas fan, 3-Combined burner, 4-Incinerator, 5-Induced draft fan, 6-Chimney, 7-Boundary butterfly valve, 8-Bypass pipeline first-hand valve, 9-Waste gas pipeline first-hand valve, 10-Bypass pipeline switch valve, 11-Waste gas pipeline switch valve, 12-Bypass pipeline second-hand valve, 13-Waste gas pipeline second-hand valve, 14-Incinerator flame arrester, 15-Combustible alarm LEL, 16-Incinerator after-treatment system, 17-Bypass pipeline. Detailed Implementation

[0025] Embodiments of the present application are described below in the detailed description and illustrated in the accompanying drawings by way of examples which, as will become apparent to those skilled in the art upon reading the following detailed description and examples, are included to provide illustrative support for the preferred embodiments of the present application and are not intended to be limiting of the application. The examples described herein are intended to be illustrative of the application and are not intended to limit the scope of the application.

[0026] Referring to Figure 1 The present application provides a direct-fired incinerator emergency state exhaust flue 6 system, the direct-fired incinerator emergency state exhaust flue 6 system includes incinerator 4, exhaust fan 2, combined burner 3, incinerator aftertreatment system 16, bypass pipe 17, induced draft fan 5 and chimney 6, the output end of the exhaust fan 2 is connected with the upstream mixed exhaust gas source 1 through the pipeline, the output end of the exhaust fan 2 is connected with the incinerator 4 through the pipeline, the incinerator 4 is provided with the combined burner 3 close to one end of the exhaust fan 2, the incinerator 4 is connected with the incinerator aftertreatment system 16 through the pipeline far from one end of the combined burner 3, the input end of the induced draft fan 5 is connected with the incinerator aftertreatment system 16 through the pipeline, the output end of the induced draft fan 5 is connected with the chimney 6 through the pipeline;

[0027] The upstream mixed exhaust gas source 1 is connected with the input end of the exhaust fan 2 on the pipeline, and the boundary butterfly valve 7, the combustible alarm instrument LEL 15 and the exhaust pipe switch valve 11 are sequentially arranged on the pipeline, the output end of the exhaust fan 2 is connected with the incinerator 4 on the pipeline, and the incinerator fire arrester 14 is arranged between the pipeline, the opening position of the bypass pipe 17 is arranged on the pipeline between the combustible alarm instrument LEL 15 and the exhaust pipe switch valve 11, the outlet position of the bypass pipe 17 is arranged on the pipeline between the incinerator aftertreatment system 16 and the input end of the induced draft fan 5, and the bypass pipe 17 is sequentially provided with the bypass pipe switch valve 10.

[0028] In the present embodiment, during the incineration process of the mixed waste gas containing combustible gas, the combustible alarm instrument LEL15 is used to monitor the mixed waste gas containing combustible gas in real time. When the concentration monitored by the combustible alarm instrument LEL15 is below 25%, the incinerator 4 is normally incinerated, the waste gas enters the incinerator 4 through the waste gas fan 2 for sufficient combustion, and then is treated by the downstream incinerator post-treatment system 16 and then is introduced into the chimney 6 through the induced draft fan 5 for high-altitude standard emission. When the concentration monitored by the combustible alarm instrument LEL15 is 25% or above, the waste gas pipeline switch valve 11 is interlocked to be closed, the bypass pipeline switch valve 10 is interlocked to be opened, and the induced draft fan 5 remains to be operated. The waste gas is introduced into the chimney 6 through the bypass pipeline 17 and the induced draft fan 5, and is directly discharged through the chimney 6 for high-altitude emission. When the concentration monitored by the combustible alarm instrument LEL15 returns to below 25%, the bypass pipeline switch valve 10 is manually closed, and the residual high-concentration combustible mixed gas in the bypass pipeline 17 is exhausted through the operation of the induced draft fan 5. At this time, the emergency discharge is completed, the residual high-concentration waste gas in the bypass pipeline 17 is avoided, the risk of combustible explosion is avoided, and the safety hidden danger of personnel life and property is reduced.

[0029] Further, the waste gas pipeline first hand valve 9 and the waste gas pipeline second hand valve 13 are arranged on the two sides of the waste gas pipeline switch valve 11 respectively. The waste gas pipeline first hand valve 9 is located between the waste gas pipeline switch valve 11 and the combustible alarm instrument LEL15. The waste gas pipeline second hand valve 13 is located between the waste gas pipeline switch valve 11 and the input end of the waste gas fan 2.

[0030] Further, the bypass pipeline first hand valve 10 and the bypass pipeline second hand valve 12 are arranged on the two sides of the bypass pipeline switch valve 10 respectively. The bypass pipeline first hand valve 10 is located between the bypass pipeline switch valve 10 and the combustible alarm instrument LEL15. The bypass pipeline second hand valve 12 is located between the bypass pipeline switch valve 10 and the input end of the waste gas fan 2.

[0031] Further, the shortest distance between the combustible alarm instrument LEL15 and the waste gas pipeline switch valve 11 is 100 meters.

[0032] Further, the number of the combustible alarm instrument LEL15 is not less than 2 sets.

[0033] Further, the opening position of the bypass pipeline 17 is arranged between the combustible alarm instrument LEL15 and the waste gas pipeline first hand valve 9.

[0034] Please refer to Figure 2The application also provides a method for discharging waste gas to a chimney 6 in an emergency state of a direct combustion incinerator, which is applied to the system for discharging waste gas to the chimney 6 in the emergency state of the direct combustion incinerator according to claim 1, and characterized by comprising the following steps:

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

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

[0037] S3: during the incineration treatment of the mixed waste gas containing combustible gas, the combustible alarm instrument LEL 15 is used to monitor the mixed waste gas containing combustible gas in real time;

[0038] S4: when the combustible alarm instrument LEL 15 monitors that the concentration is below 25%, the incinerator 4 is normally incinerated and operated, waste gas enters the incinerator 4 through the waste gas fan 2 for sufficient combustion, and then is treated by the downstream incinerator post-treatment system 16 and is introduced to the chimney 6 through the induced draft fan 5 for high-altitude discharge meeting the standard;

[0039] S5: when the combustible alarm instrument LEL 15 monitors that the concentration is 25% or above 25%, the waste gas pipeline switch valve 11 is closed and the bypass pipeline switch valve 10 is opened, the induced draft fan 5 keeps running, waste gas is introduced to the chimney 6 through the bypass pipeline 17 and the induced draft fan 5, and is directly discharged through the chimney 6 for high-altitude discharge;

[0040] S6: when the combustible alarm instrument LEL 15 monitors that the concentration returns to below 25%, before the bypass pipeline switch valve 10 is manually closed, the bypass pipeline 17 is exhausted of residual high-concentration combustible mixed gas through the running of the induced draft fan 5, and at this time, the emergency discharge is completed.

[0041] In the present embodiment, the mixed waste gas containing combustible gas generated by the upstream mixed waste gas source 1 is introduced into the incinerator 4 through the waste gas fan 2 for incineration treatment, and the high-temperature flue gas after incineration is treated by the incinerator post-treatment system 16 (after incineration, the high-temperature flue gas is used for waste heat utilization by a boiler and a flue gas heat exchanger, and then is cooled by a quenching tower to inhibit the generation of dioxin by quenching, the flue gas after quenching treatment is subjected to alkali washing and acid removal by an alkali washing tower, the discharged flue gas is heated by a heat exchanger and a pipe burner, and then enters a subsequent SCR denitration device, and the purified flue gas is further subjected to waste heat utilization by an air preheater), under the action of the induced draft fan 5, is transported to the chimney 6 for emission. In the incineration treatment process of the mixed waste gas containing combustible gas, the combustible alarm instrument LEL 15 is used to monitor the mixed waste gas containing combustible gas in real time. When the concentration monitored by the combustible alarm instrument LEL 15 is below 25%, the incinerator 4 is normally incinerated and operated, the waste gas enters the incinerator 4 through the waste gas fan 2 for sufficient combustion, and then is treated by the downstream incinerator post-treatment system 16, and is introduced to the chimney 6 by the induced draft fan 5 for high-altitude emission. When the concentration monitored by the combustible alarm instrument LEL 15 is 25% or above, the waste gas pipeline on-off valve 11 is closed and the bypass pipeline on-off valve 10 is opened, the induced draft fan 5 remains running, the waste gas is introduced to the chimney 6 through the bypass pipeline 17 and the induced draft fan 5, and is directly emitted through the chimney 6 at high altitude. When the concentration monitored by the combustible alarm instrument LEL 15 returns to below 25%, the bypass pipeline on-off valve 10 is manually closed, and the residual high-concentration combustible mixed gas in the bypass pipeline 17 is exhausted by the operation of the induced draft fan 5. At this time, the emergency emission is completed, the high-concentration waste gas is avoided to be left in the bypass pipeline 17, the risk of combustible explosion is avoided, and the safety hidden danger of personnel life and property is reduced.

[0042] The above only discloses a preferred embodiment of the present application, and of course cannot limit the scope of the present application. Those skilled in the art can understand that the above-mentioned processes can be implemented in whole or in part, and equivalent changes made according to the claims of the present application still fall within the scope of the present application.

Claims

1. A direct-fired incinerator exhaust gas chimney system in an emergency state, characterized in that, comprising an incinerator, an exhaust gas fan, a combined burner, an incinerator post-processing system, a bypass pipeline, an induced draft fan and a chimney, the output end of the exhaust gas fan is connected with an upstream mixed exhaust gas source through a pipeline, the output end of the exhaust gas fan is connected with the incinerator through a pipeline, the end of the incinerator close to the exhaust gas fan is provided with the combined burner, the end of the incinerator away from the combined burner is connected with the incinerator post-processing system through a pipeline, the input end of the induced draft fan is connected with the incinerator post-processing system through a pipeline, and the output end of the induced draft fan is connected with the chimney through a pipeline; a boundary butterfly valve, a combustible alarm instrument LEL and an exhaust gas pipeline switch valve are sequentially arranged on the pipeline connected with the input end of the exhaust gas fan and the upstream mixed exhaust gas source, an incinerator fire damper is arranged between the output end of the exhaust gas fan and the pipeline connected with the incinerator, the opening position of the bypass pipeline is arranged on the pipeline between the combustible alarm instrument LEL and the exhaust gas pipeline switch valve, the outlet position of the bypass pipeline is arranged on the pipeline between the incinerator post-processing system and the input end of the induced draft fan, and a bypass pipeline switch valve is sequentially arranged on the bypass pipeline.

2. The direct-fired incinerator exhaust gas chimney system in an emergency state according to claim 1, characterized in that, a first exhaust gas pipeline hand valve and a second exhaust gas pipeline hand valve are arranged on the two sides of the exhaust gas pipeline switch valve respectively, the first exhaust gas pipeline hand valve is located between the exhaust gas pipeline switch valve and the combustible alarm instrument LEL, and the second exhaust gas pipeline hand valve is located between the exhaust gas pipeline switch valve and the input end of the exhaust gas fan.

3. The direct-fired incinerator exhaust gas chimney system in an emergency state according to claim 2, characterized in that, a first bypass pipeline hand valve and a second bypass pipeline hand valve are arranged on the two sides of the bypass pipeline switch valve respectively, the first bypass pipeline hand valve is located between the bypass pipeline switch valve and the combustible alarm instrument LEL, and the second bypass pipeline hand valve is located between the bypass pipeline switch valve and the input end of the exhaust gas fan.

4. The direct-fired incinerator exhaust gas chimney system in an emergency state according to claim 3, characterized in that, the shortest distance between the combustible alarm instrument LEL and the exhaust gas pipeline switch valve is 100 meters.

5. The direct-fired incinerator exhaust gas chimney system in an emergency state according to claim 4, characterized in that, the number of combustible alarm instruments LEL is not less than 2 sets.

6. The direct-fired incinerator exhaust gas chimney system in an emergency state according to claim 5, characterized in that, the opening position of the bypass pipeline is arranged between the combustible alarm instrument LEL and the first exhaust gas pipeline hand valve.

7. A method for discharging exhaust gas to a chimney in an emergency state of a direct-fired incinerator, applied to the system for discharging exhaust gas to a chimney in an emergency state of a direct-fired incinerator according to claim 1, characterized in that, comprising the following steps: the mixed exhaust gas containing combustible gas generated by the upstream mixed exhaust gas source is introduced into the incinerator through the exhaust gas fan for incineration treatment; after incineration, the high-temperature flue gas is post-processed through the incinerator post-processing system, and then is transported to the chimney for emission under the action of the induced draft fan. In the incineration process of 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 the concentration below 25%, the incinerator is normally incinerated, the waste gas enters the incinerator through the waste gas fan for sufficient combustion, and then is treated by the downstream incinerator post-treatment system, and then is introduced into the chimney by the induced draft fan for high-altitude standard emission; When the combustible alarm LEL monitors the concentration of 25% and above, the waste gas pipeline switch valve is closed, the bypass pipeline switch valve is opened, the induced draft fan remains running, the waste gas is introduced into the chimney through the bypass pipeline and the induced draft fan, and is directly discharged through the chimney for high-altitude emission; When the combustible alarm LEL monitors the concentration to return below 25%, the bypass pipeline switch valve is manually closed, the residual high-concentration combustible mixed gas in the bypass pipeline is exhausted through the operation of the induced draft fan, and at this time the emergency discharge is completed.

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