CN214120081U

CN214120081U - Waste incineration grate furnace reburning denitration methane treatment system

Info

Publication number: CN214120081U
Application number: CN202023192511.8U
Authority: CN
Inventors: 龙吉生; 单福朋; 李建平; 严浩文; 王玮; 余国涛; 张坡; 袁旗斌; 乔旭; 贾敏华
Original assignee: Shanghai SUS Environment Co Ltd
Current assignee: Shanghai SUS Environment Co Ltd
Priority date: 2020-12-27
Filing date: 2020-12-27
Publication date: 2021-09-03
Anticipated expiration: 2030-12-27

Abstract

The utility model is suitable for the field of household garbage incineration, and is a garbage incineration grate furnace reburning denitration treatment methane system, which consists of a hearth methane back-spraying nozzle, a secondary air nozzle, a methane conveying device, a pneumatic regulating valve, a pressure switch, a flame retardant, a grate and a flue; the biogas back-spraying nozzles are arranged in the front arch area and the rear arch area, and the inclination angles of the nozzles are arranged according to the structure of the hearth, so that the flue gas is fully mixed, and the residence time of the flue gas is prolonged; the secondary air nozzle is arranged at the upper part of the biogas back-spray nozzle to supplement oxygen to ensure that the combustible gas is completely combusted; the biogas is taken from a leachate anaerobic fermentation system and is conveyed by the biogasThe apparatus is sent into a furnace. The utility model can enter the high-temperature oxygen-poor area of the hearth through spraying methane to treat the methane, and simultaneously reduce NOx into N₂. The utility model has the functions of adjusting the methane volume entering the furnace and protecting the safety of the whole system through the methane system protection device. The utility model discloses the accessible supplements the overgrate air and makes combustible substance burn completely.

Description

Waste incineration grate furnace reburning denitration methane treatment system

Technical Field

The utility model is suitable for a domestic waste burns the field, especially a msw incineration grate furnace reburning denitration treatment marsh gas system.

Background

The leachate treatment station is a conventional configuration facility of a waste incineration plant, and leachate can generate a large amount of combustible gases such as methane and the like after anaerobic fermentation, wherein the heat value of the methane is high and can reach 24MJ/Nm³However, in general incineration plants, biogas is burned by a torch, which causes energy waste. In recent years, most waste incineration plants are provided with a biogas burner, biogas enters a furnace through the burner for incineration, so that the heat of the biogas is fully utilized, but the temperature in the furnace is increased due to the fact that the biogas enters the furnace for combustion, and the risks of coking of a hearth and increase of NOx emission concentration are increased.

SUMMERY OF THE UTILITY MODEL

Reburning denitration, namely, reburning fuel is mixed with NOx to react under reducing atmosphere to generate N₂The utility model aims to utilize the principle of reburning denitration, set a methane back-spraying nozzle in the oxygen-deficient high-temperature area at the lower part of the secondary air nozzle, and react with NOx by using reducing gases such as methane and the like to reduce NOx into N₂CO is produced and then overflowed by supplying secondary air in the upper region. The utility model discloses not only can handle leachate marsh gas, can also reduce NOx's emission concentration, reduce SNCR system spout ammonia volume, improve combustion efficiency, it is less to furnace temperature influence simultaneously.

The utility model discloses a concrete technical scheme is a waste incineration grate furnace reburning denitration treatment marsh gas system comprises furnace marsh gas return spray nozzle, overgrate air nozzle, marsh gas conveyor, pneumatic control valve, pressure switch, flame arrester, grate, flue. The biogas back-spraying nozzles are arranged in the front arch area and the rear arch area, the designed flow speed is about 60m/s, and the inclination angles of the nozzles are arranged according to the hearth structure, so that the flue gas is fully mixed, and the residence time of the flue gas is prolonged. The secondary air nozzle is arranged at the upper part of the methane back-spray nozzle to supplement oxygen to ensure that the combustible gas is completely combusted. The biogas is taken from the leachate anaerobic fermentation system and is conveyed into the furnace through a biogas conveying device.

The incinerator is composed of a stepped grate with an inclination angle, a front arch, a rear arch, side walls and a flue, a biogas back-spray nozzle and a secondary air nozzle are arranged at the front arch and the rear arch, the biogas back-spray nozzle is respectively arranged at an oxygen-poor area at the upper part of a main combustion area of the front arch and the rear arch, a nozzle in a front arch area is horizontally arranged downwards, and a nozzle in a rear arch area is horizontally arranged. The biogas is taken from a leachate anaerobic fermentation system and is output from a biogas storage tank, the flow is controlled by a pneumatic regulating valve, a pressure regulating system is arranged for maintaining the system pressure, enhancing the gas mixing turbulence and improving the retention time of mixed gas, a gas-water separating system can separate moisture in the biogas, and a pressure switch and a flame arrester prevent smoke or flame from entering a biogas pipeline system. When the section temperature of the biogas nozzle reaches the set temperature, biogas is sprayed into the furnace through the nozzle, and at the moment, the methane and NOx generate chain reaction to reduce the NOx into N₂CO is produced. The secondary air nozzles are arranged at the upper parts of the front arch methane nozzles and the rear arch methane nozzles, the arrangement angle is consistent with that of the methane back-spraying nozzles, partial air is sprayed to completely burn combustible materials, and the furnace temperature is adjusted.

When the incinerator is normally combusted, the biogas is sent to a biogas return spray nozzle to be sprayed into the incinerator, the biogas and the biogas are mixed at the position of an oxygen-poor area with the incinerator temperature of 1000 DEG CMinute NO_xProducing chain reaction to N₂And CO, which replenishes a portion of the air in the upper region to provide for a complete combustion of the combustible material. Meanwhile, the system is provided with multiple protection devices, the pressure switch and the flame arrester prevent smoke from flowing backwards and prevent flame from entering the methane conveying pipeline, and the methane sprayed into the furnace is less than 1% of the total amount of the smoke, so that the strong explosion condition cannot be generated in the furnace.

Furthermore, the utility model discloses can get into furnace high temperature oxygen poor district through spouting marsh gas and handle marsh gas, make NOx reduce into N simultaneously₂。

Furthermore, the utility model adjusts the amount of the methane entering the furnace through the adjusting door.

Further, the utility model discloses a pressure regulating system maintains system's pressure, strengthens gaseous mixture.

Furthermore, the utility model discloses a moisture in the marsh gas is arranged out to gas-water separation system to the better reaction of reburning fuel.

Furthermore, the utility model protects the safety of the whole system through the methane system protection device.

Furthermore, the utility model discloses can improve leachate marsh gas utilization efficiency, reduce SNCR's ammonia injection volume.

Further, the utility model discloses can make the CO that reburning the denitration production fully burn through replenishing the overgrate air.

The utility model discloses a reburning denitration technique handles marsh gas, can the at utmost utilize the energy, improves combustion efficiency, reduces the ammonia injection volume of SNCR system, reduces the material consumption, simultaneously, can effectively solve the condition that directly spout into the flame region and cause local high temperature.

The present invention will be further explained with reference to the accompanying drawings and embodiments.

Drawings

FIG. 1 is a schematic view of a system for reburning denitration treated biogas.

Fig. 2 is an implementation process flow diagram.

In fig. 1: 1. the biogas system comprises a biogas storage tank, 2. an explosion-proof pneumatic regulating valve, 3. a pressure regulating system, 4. a gas-water separation system, 5. a pressure gauge, 6. a pressure switch, 7. a flame arrester, 8. a biogas back-spray nozzle, 9. a secondary air nozzle, 10. a fire grate and 11. a flue.

Detailed Description

As shown in figure 1, the incinerator is composed of a step grate (10) with an inclination angle, a front arch, a rear arch, side walls and a flue (11), a biogas back-spray nozzle (8) and a secondary air nozzle (9) are arranged at the position of the front arch and the rear arch, the biogas back-spray nozzle (8) is respectively arranged at an oxygen-poor area at the upper part of a main combustion area of the front arch and the rear arch, a nozzle of the front arch area is horizontally arranged downwards by 20 degrees, and a nozzle of the rear arch area is horizontally arranged. Biogas is taken from a leachate anaerobic fermentation system and is output from a biogas storage tank (1), the flow is controlled by a pneumatic regulating valve (2), a pressure regulating system (3) is arranged for maintaining the system pressure, enhancing the gas mixing turbulence and improving the retention time of mixed gas, a gas-water separation system (4) can separate moisture in the biogas, and a pressure gauge (5), a pressure switch (6) and a flame arrester (7) prevent smoke or flame from entering a biogas pipeline system. When the temperature of the cross section of the biogas nozzle reaches 1000 ℃, biogas is sprayed into the furnace through the nozzle (8), and at the moment, the methane and NOx generate chain reaction to reduce the NOx into N₂CO is produced. The secondary air nozzles (9) are arranged at the upper parts of the biogas nozzles (8) of the front arch and the rear arch, the arrangement angle is consistent with that of the biogas back-spraying nozzles (8), partial air is sprayed to completely burn combustible materials, and the furnace temperature is adjusted.

As shown in figure 2, when the incinerator is normally combusted, the biogas is sent to a biogas back-spray nozzle to be sprayed into the incinerator, the position is an oxygen-poor area with the incinerator temperature of 1000 ℃, and the biogas and part of NO are sprayed into the incinerator_xProducing chain reaction to N₂And CO, which replenishes a portion of the air in the upper region to provide for a complete combustion of the combustible material. Meanwhile, the system is provided with multiple protection devices, the pressure switch and the flame arrester prevent smoke from flowing backwards and prevent flame from entering the methane conveying pipeline, and the methane sprayed into the furnace is less than 1% of the total amount of the smoke, so that the strong explosion condition cannot be generated in the furnace.

The reburning denitration can achieve a good denitration effect only under a certain environment atmosphere, the residence time, the temperature, the excess air coefficient and the mixing effect of a reburning area are related to the concentration of reburning fuel, the denitration efficiency of the reburning fuel which is generally methane is used can reach more than 20%, and in addition, the system is superior to direct combustion by a torch and combustion by a burner when used for treating the leachate station methane.

Claims

1. A waste incineration grate furnace reburning denitration treatment biogas system is characterized by comprising a hearth biogas back-spray nozzle, a secondary air nozzle, a biogas conveying device, a pneumatic regulating valve, a pressure switch, a flame retardant device, a grate and a flue; the incinerator consists of a stepped grate with an inclination angle, a front arch, a rear arch, side walls and a flue, a biogas back-spray nozzle and a secondary air nozzle are arranged at the positions of the front arch and the rear arch, the biogas back-spray nozzle is respectively arranged in an oxygen-poor area at the upper part of a main combustion area of the front arch and the rear arch, a nozzle in the front arch area is horizontally arranged downwards, and a nozzle in the rear arch area is horizontally arranged; the biogas is taken from a leachate anaerobic fermentation system and is output from a biogas storage tank, the flow is controlled by a pneumatic regulating valve, a pressure regulating system is arranged for maintaining the system pressure, enhancing the gas mixing turbulence and improving the retention time of mixed gas, a gas-water separating system can separate moisture in the biogas, and a pressure switch and a flame arrester prevent smoke or flame from entering a biogas pipeline system; when the section temperature of the biogas nozzle reaches the set temperature, biogas is sprayed into the furnace through the nozzle, and at the moment, the methane and NOx generate chain reaction to reduce the NOx into N₂CO is produced; the secondary air nozzles are arranged at the upper parts of the front arch methane nozzles and the rear arch methane nozzles, the arrangement angle is consistent with that of the methane back-spraying nozzles, partial air is sprayed to completely burn combustible materials, and the furnace temperature is adjusted.