A waste incinerator slag and dust control device and method

Abstract

The application discloses a waste incinerator slag falling and dust raising control device and method, which comprises a chain control grate pushing module and an air induction control module. The air induction control module comprises a flue damper door, a flue gas pipeline, a variable frequency fan and a partition valve. The inlet end of the flue gas pipeline is arranged on the rear wall of the incinerator below the flame monitoring probe of the hearth. The flue damper door is arranged in the flue gas pipeline. The air inlet of the variable frequency fan is connected with the outlet end of the flue gas pipeline, and the air outlet pipeline is connected with the water seal of the slag extractor. The partition valve is arranged on the air outlet pipeline of the variable frequency fan above the water seal. The dust source above the slag falling well is controlled, the visibility of the flame monitoring system of the hearth during slag falling is improved, the stability of the combustion condition is ensured, the long-period operation of the flame monitoring probe is ensured, the phenomena of coking and ash deposition are relieved, and the economy, safety, environmental protection and stability of the waste power plant are improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of slag and dust control, and particularly relates to a waste incinerator slag and dust control device and method. BACKGROUND

[0002] Incineration disposal is one of the ideal ways for realizing resource utilization of municipal solid waste reduction, and the incinerator mainly includes a circulating fluidized bed and a mechanical grate furnace. The grate furnace has a wide application range and stable performance, and is most widely used in China.

[0003] The control of waste input into the incinerator and the thickness of the loading layer on the grate is performed by adjusting the waste feeder and the grate period. One action cycle of the grate includes: intermediate limit, forward limit, intermediate limit, backward limit, and intermediate limit. The action cycle of the grate in the burnout section is basically not changed, and when the downstream equipment such as the slag extractor and the ash conveyor fails and stops for a long time, the action cycle needs to be extended to avoid the ash and slag from falling into the slag extractor. The combustion condition and the thickness of the loading layer have no direct parameter reaction, and mainly rely on the observation of the flame signal of the furnace and the observation of the on-site observation hole to check the combustion condition. The waste realizes complete combustion after passing through the drying section, the combustion section and the burnout section. Except for a small amount of ash falling from the gap between the grates and being conveyed to the slag extractor through the inclined pipe, most of the slag is conveyed from the burnout section to the slag extractor through the slag well. In recent years, waste power plants generally mix and burn stale waste from waste landfills with raw municipal waste (about 30% to 50%), which contains a large amount of inorganic matter (such as gravel, bricks, glass, ceramics, clay, sand and gravel, etc.), resulting in a sharp increase in the concentration of dust above the slag well, which has many adverse effects on production:

[0004] (1) The observation hole and the furnace flame monitor probe are usually installed on the back wall of the incinerator. When the slag falls, the visibility at the back wall of the furnace is almost zero and lasts for a period of time. On the one hand, it causes the operation personnel to be unable to monitor the combustion condition of the furnace and to make timely adjustments, affecting the stable operation, and on the other hand, the dust deposited on the flame monitoring probe cannot be monitored after a certain period of time, and manual cleaning is required, affecting the monitoring of the furnace condition;

[0005] (2) A large amount of dust raised during slag falling is wrapped in the downstream flue gas (including waste heat utilization and flue gas purification facilities / equipment) flow surface, increasing the risk of coking and ash deposition, reducing the waste heat recovery rate, increasing the flue gas flow resistance, reducing the flue gas deacidification reaction efficiency, causing the boiler output to decrease, the boiler induced draft fan power consumption to increase, the flue gas deacidification material consumption and fly ash treatment and disposal cost to increase;

[0006] (3) Coking can cause local overheating of the heating surface, and cracks caused by long-term excessive stress can cause steam-water pipe explosion. In addition, boiler decoking is a limited space operation, which has the risk of high altitude, high temperature and falling objects;

[0007] (4)Coking and blocking can shorten the operation cycle of the boiler, increase the frequency of boiler fire and start-stop, increase the probability of incomplete combustion of garbage, and increase the generation of pollutants such as CO and dioxin. SUMMARY

[0008] The technical problem solved by the present application is that the present application provides a garbage incinerator slag falling dust control device and method, which controls the dust source above the slag falling well, on the one hand, improves the visibility of the furnace flame monitoring system during slag falling, ensures the stability of the combustion condition and prolongs the continuous operation cycle of the flame monitoring probe, and on the other hand, alleviates the phenomenon of coking and ash blocking, and improves the economy, safety, environmental protection and stability of the garbage power plant.

[0009] Technical scheme: A garbage incinerator slag falling dust control device, comprising a chain control grate pushing module and an induced draft control module, the induced draft control module comprising a flue damper door, a flue gas pipeline, a variable frequency fan and a partition valve, the inlet end of the flue gas pipeline being arranged on the rear wall of the incinerator below the flame monitoring probe; the flue damper door being arranged in the flue gas pipeline; the air inlet of the variable frequency fan being connected to the outlet end of the flue gas pipeline, and the air outlet pipeline being connected to the water seal of the slag extractor; the partition valve being arranged on the air outlet pipeline of the variable frequency fan above the water seal; the induced draft control module is started 30-60s before the grate pushing module: the partition valve is opened, the variable frequency fan is operated, and the flue damper door is opened; after 30-60s, the grate pushing module starts the pushing period; when the grate pushing module completes a complete pushing period: after 30-60s, the flue damper door is closed, and the variable frequency fan is idling for 30s, and the partition valve is closed.

[0010] Preferably, the inlet end of the flue gas pipeline is provided with a check valve.

[0011] Preferably, the inlet end of the flue gas pipeline is a gradually tapered surrounding cover.

[0012] Preferably, the flue damper door and the partition valve are arranged in the vertical section of the flue gas pipeline.

[0013] Preferably, a flow sensor is arranged on the flue gas pipeline.

[0014] Preferably, the device further comprises a pressure monitoring module for interlocking the induced draft control module, the pressure monitoring module comprising pressure sensors arranged in the furnace and in the flue gas pipeline respectively, for monitoring and comparing the pressure in the furnace and the flue gas pipeline, and transmitting the comparison result to the induced draft control module.

[0015] Preferably, the device further comprises a slag conveyor water temperature monitoring module and a slag conveyor water level monitoring module which are linked to control the water supplement module, the slag conveyor water temperature monitoring module is used for monitoring the water temperature in the water seal and comparing with the set value, the slag conveyor water level monitoring module is used for monitoring the water level in the water seal and comparing with the set value, and the water supplement module is used for receiving the comparison results of the slag conveyor water temperature monitoring module and the slag conveyor water level monitoring module and supplementing water.

[0016] The dust control method based on the waste incinerator slag falling dust control device comprises the following steps: before the material is pushed by the furnace grate, the smoke flue baffle door, the variable frequency fan and the partition valve are in the closed state; the air induction control module is started 30-60s before the furnace grate pushing module: the partition valve is opened, the variable frequency fan is operated, and the smoke flue baffle door is opened; after 30-60s, the furnace grate pushing module starts the material pushing period; the dust-containing flue gas in the slag falls into the water seal of the slag conveyor through the flue gas pipeline, the particulate matters in the dust-containing flue gas are left in the water seal, and the cooled flue gas returns to the incinerator after heat exchange with the high-temperature slag in the slag falling well; when the furnace grate pushing module completes a complete material pushing period: after 30-60s, the smoke flue baffle door is closed, and after a delay of 30s, the variable frequency fan enters the idle speed operation state, and the partition valve is closed.

[0017] Preferably, the device further comprises a pressure monitoring module which is linked to control the air induction control module, the pressure monitoring module comprises pressure sensors arranged in the furnace chamber and the flue gas pipeline respectively, and is used for monitoring and comparing the pressure in the furnace chamber and the flue gas pipeline; when the pressure in the furnace chamber is less than the pressure in the flue gas pipeline, the opening degree of the smoke flue baffle door is reduced; when the pressure in the furnace chamber is greater than the pressure in the flue gas pipeline, the opening degree of the smoke flue baffle door is increased.

[0018] Preferably, the device further comprises a slag conveyor water temperature monitoring module and a slag conveyor water level monitoring module which are linked to control the water supplement module; when the slag conveyor water temperature monitoring module monitors that the water temperature is greater than the set value, the water supplement module supplements water; when the slag conveyor water level monitoring module monitors that the water level is lower than the set value, the water supplement module supplements water.

[0019] Beneficial effects: the application can guarantee the long-period safe and stable operation of the waste incineration power plant.

[0020] Through the dust source control and purification treatment of the high-dust-concentration flue gas dust source above the slag falling well, the coking risk of the waste heat utilization system and the blockage risk of the flue gas purification system can be reduced, and the availability, economy, stability and safety of the waste incineration power plant can be improved.

[0021] The dust source control can greatly improve the availability of the furnace flame monitoring system, and is beneficial to monitoring the combustion condition of the furnace and improving the working condition stability of the incineration power plant.

[0022] The slag falls and the flue gas passing through the water seal forms a countercurrent, the low-temperature flue gas cools the slag and strengthens the slag cooling; meanwhile, the temperature of the flue gas after the water bath is increased;

[0023] The extracted flue gas has a high temperature, can preheat the air leakage of the slag extractor, and relieves the influence of the infiltration of cold air on the burnout section at the tail of the grate;

[0024] The device is simple, the control logic is simple, the investment cost is low, the construction period is short, and is suitable for new projects or adaptive modification of existing projects. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a device structure schematic diagram of the present application;

[0026] Figure 2 is a structure schematic diagram of the induced draft control module;

[0027] In the figure, each number represents the following: 1. grate of the incinerator; 2. flame monitoring probe; 3. burner; 4. rear wall of the incinerator; 5. check valve; 6. flue damper door; 7. flow sensor; 8. slag falling well; 9. flue gas pipeline; 10. variable frequency fan; 11. cut-off valve; 12. slag extractor. DETAILED DESCRIPTION

[0028] The present application will be further described below in combination with the drawings and specific examples. Example 1

[0029] As shown in Figure 1 and Figure 2 , the present application provides a slag falling and dust raising control device of a waste incinerator, which comprises a grate pushing module and an induced draft control module in a chain control. The waste incinerator adopts a mechanical grate, and a burner 3 is arranged on the rear wall 4 of the incinerator corresponding to the burnout section, so that the unburnt waste can be heated and combusted again; a flame monitoring probe 2 is arranged above the burner 3, so that the waste incineration condition in the hearth can be observed and monitored. The induced draft control module comprises a flue damper door 6, a flue gas pipeline 9, a variable frequency fan 10 and a cut-off valve 11.

[0030] The flue gas pipeline 9 is lined with castable or daubing material, which can resist high temperature, and the inlet end thereof is a diameter-tapered enclosure, which is arranged on the rear wall 4 of the incinerator and located below the flame monitoring probe 2. The check valve 5 is arranged at the inlet end of the flue gas pipeline 9, so as to prevent backflow. The flow sensor 7 is arranged on the flue gas pipeline 9, so as to display the flow change caused by the frequency adjustment of the variable frequency fan 10.

[0031] The flue damper door 6 is arranged in the flue gas pipeline 9 and located at the vertical section of the flue gas pipeline 9, so as to prevent the flue gas pipeline 9 from being blocked by ash accumulation.

[0032] The variable frequency fan 10 is made of wear-resistant and corrosion-resistant material, the air inlet is connected with the outlet end of the flue gas pipeline 9, and the air outlet pipeline is connected with the water seal of the slag extractor 12, and the suction force is greater than the negative pressure suction force in the furnace chamber of the incinerator.

[0033] The partition valve 11 is arranged in the air outlet pipeline of the variable frequency fan 10 and located above the water seal, and is used for isolating steam.

[0034] The induced draft control module is started 30-60s before the grate pushing module 30-60s, that is, the partition valve 11 is opened, at the same time, the variable frequency fan 10 is operated at high speed, and the flue damper door 6 is opened, and after 30-60s, the grate pushing module starts the pushing period, and the tail high-dust flue gas of the grate combustion section is extracted into the water seal of the slag extractor 12; when the grate pushing module completes a complete pushing period, the flue damper door 6 is closed after 30-60s, and the variable frequency fan 10 is in the idling state after being delayed for 30s, and the partition valve 11 is closed.

[0035] The device further comprises a pressure monitoring module connected with the induced draft control module, the pressure monitoring module comprises pressure sensors arranged in the furnace chamber and in the flue gas pipeline 9 respectively, and is used for monitoring and comparing the pressure in the furnace chamber and the pressure in the flue gas pipeline 9 and transmitting the comparison result to the induced draft control module.

[0036] The device further comprises a slag extractor water temperature monitoring module and a slag extractor water level monitoring module connected with the control water supply module, the slag extractor water temperature monitoring module is used for monitoring the water temperature in the water seal and comparing with the set value, the slag extractor water level monitoring module is used for monitoring the water level in the water seal and comparing with the set value, and the water supply module is used for receiving the comparison results of the slag extractor water temperature monitoring module and the slag extractor water level monitoring module and supplying water.

[0037] The dust control method based on the above-mentioned garbage incinerator slag falling dust control device comprises the following steps:

[0038] Before pushing, the flue damper door 6, the variable frequency fan 10 and the partition valve 11 are in the closed state.

[0039] When the pushing is about to start, the air control module starts 30-60s before the pushing module of the furnace, that is, the partition valve 11 is opened first, and the frequency conversion fan 10 runs at high speed, and the flue damper door 6 is opened, and after 30-60s, the pushing cycle of the pushing module of the furnace is started. The dust-containing flue gas in the slag falling is introduced into the water seal of the slag extractor 11 through the flue gas pipeline 9, and the particulate matter in the dust-containing flue gas is left in the water seal, and the cooled flue gas rises back to the incinerator after heat exchange with the high-temperature slag in the slag falling well 8. During the process, the opening of the flue damper door 6 is adjusted according to the data of the pressure monitoring module to adjust the air pressure to ensure that it is greater than the negative pressure of the furnace, specifically: when the pressure in the furnace is less than the pressure in the flue gas pipeline 9, the opening of the flue damper door 6 is reduced; when the pressure in the furnace is greater than the pressure in the flue gas pipeline 9, the opening of the flue damper door 6 is increased.

[0040] When the pushing module of the furnace completes a complete pushing cycle, the flue damper door 6 is closed after 30-60s, and the frequency conversion fan 10 enters the idling state after a delay of 30s, and the partition valve 11 is closed. Because the tail flue gas enters the water seal of the slag extractor 11, it will cause liquid level fluctuation, water temperature rise and water evaporation, so when the water temperature monitoring module of the slag extractor monitors that the water temperature is greater than the set value, the water supplement module performs water supplement. Because the liquid level fluctuation will cause part of the water to be discharged from the overflow port, the water level monitoring is not accurate, so after the liquid level fluctuation stops, when the water level monitoring module of the slag extractor monitors that the water level is lower than the set value, the water supplement module performs water supplement.

[0041] The present application can guarantee the long-period safe and stable operation of the waste incineration power plant:

[0042] Through the dust source control and purification treatment of the high-dust-concentration flue gas above the slag falling well 8, the coking risk of the waste heat utilization system and the blockage risk of the flue gas purification system can be reduced, and the availability, economy, stability and safety of the waste incineration power plant can be improved;

[0043] The dust source control can greatly improve the availability of the furnace flame monitoring system, which is conducive to monitoring the combustion condition of the furnace and improving the working condition stability of the incineration power plant;

[0044] The slag falling and the flue gas passing through the water seal form a countercurrent, the low-temperature flue gas has a cooling effect on the slag, and the cooling of the slag is strengthened; at the same time, the temperature of the flue gas after water bath is improved;

[0045] The extracted flue gas has a high temperature, which can preheat the air leakage of the slag extractor 12, and alleviate the influence of the infiltration of cold air on the burnout section at the tail of the furnace;

[0046] The equipment is simple, the control logic is simple, the investment and operation cost are low, the construction period is short, and it is suitable for new projects or adaptive modification of existing projects.

Claims

1. A device for controlling the falling of slag and dust in a waste incinerator, characterized in that The device comprises a grate pushing module and an air induction control module, the air induction control module comprises a flue damper door (6), a flue gas pipeline (9), a variable frequency fan (10) and a partition valve (11), the inlet end of the flue gas pipeline (9) is arranged on the back wall (4) of the incinerator below the flame monitoring probe (2), the flue damper door (6) is arranged in the flue gas pipeline (9), the air inlet of the variable frequency fan (10) is connected with the outlet end of the flue gas pipeline (9), the air outlet pipeline is connected with the water seal of the slag extractor (12), and the partition valve (11) is arranged on the air outlet pipeline of the variable frequency fan (10) above the water seal.

2. A device for controlling the falling of slag and dust in a waste incinerator according to claim 1, characterized in that, The inlet end of the flue gas pipeline (9) is provided with a check valve (5).

3. A device for controlling the falling of slag and dust in a waste incinerator according to claim 1, characterized in that, The inlet end of the flue gas pipeline (9) is a gradually tapered sheath.

4. A device for controlling the falling of slag and dust in a waste incinerator according to claim 1, characterized in that, The flue damper door (6) and the flue partition valve (11) are arranged on the vertical section of the flue gas pipeline (9).

5. A device for controlling the falling of slag and dust in a waste incinerator according to claim 1, characterized in that, The flue gas pipeline (9) is provided with a flow sensor (7).

6. A device for controlling the falling of slag and dust in a waste incinerator according to claim 1, characterized in that, The device further comprises a pressure monitoring module interlocked with the air induction control module, the pressure monitoring module comprises pressure sensors arranged in the furnace and in the flue gas pipeline (9) respectively, which are used for monitoring and comparing the pressure in the furnace and the flue gas pipeline (9) and transmitting the comparison result to the air induction control module.

7. A device for controlling the falling of slag and dust in a waste incinerator according to claim 1, characterized in that, The device further comprises a slag extractor water temperature monitoring module and a slag extractor water level monitoring module interlocked with the water replenishment module, the slag extractor water temperature monitoring module is used for monitoring the water temperature in the water seal and comparing it with the set value, the slag extractor water level monitoring module is used for monitoring the water level in the water seal and comparing it with the set value, and the water replenishment module is used for receiving the comparison results of the slag extractor water temperature monitoring module and the slag extractor water level monitoring module and replenishing water.

8. The dust control method of the dust control apparatus for refuse incineration plant according to claim 1, characterized by, The device comprises the following steps: before the grate pushing of the incinerator, the flue damper door, the variable frequency fan and the partition valve are in the closed state, the air induction control module is started 30-60s earlier than the grate pushing module: the partition valve (11) is opened, the variable frequency fan (10) is operated, and the flue damper door (6) is opened, after 30-60s, the grate pushing module starts the pushing period, the dust-containing flue gas in the slag falling is introduced into the water seal of the slag extractor (12) through the flue gas pipeline (9), the particulate matters in the dust-containing flue gas are left in the water seal, the cooled flue gas is heated with the high-temperature slag in the slag falling well (8) and then returns to the incinerator, when the grate pushing module completes a complete pushing period, the flue damper door (6) is closed after 30-60s, and then the variable frequency fan (10) is in the idle speed operation state and the partition valve (11) is closed after a delay of 30s.

9. The dust control method of claim 8, wherein, The device further comprises a pressure monitoring module of the interlocking induced draft control module, the pressure monitoring module comprises pressure sensors respectively arranged in the furnace and in the flue gas pipeline (9) for monitoring and comparing the pressure in the furnace and the pressure in the flue gas pipeline (9); when the pressure in the furnace is less than the pressure in the flue gas pipeline (9), the opening of the flue damper door (6) is reduced; when the pressure in the furnace is greater than the pressure in the flue gas pipeline (9), the opening of the flue damper door (6) is increased.

10. The dust control method of claim 8, wherein, The device further comprises a water temperature monitoring module and a water level monitoring module of the interlocking control water replenishment module of the slag conveyor; when the water temperature monitoring module monitors that the water temperature is greater than a set value, the water replenishment module replenishes water; when the water level monitoring module monitors that the water level is lower than a set value, the water replenishment module replenishes water.

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