A secondary combustion chamber for incineration of hazardous waste

Abstract

The invention relates to a secondary combustion chamber for incineration of hazardous waste, comprising an inner tube, an outer tube, a top cover, a slag outlet, a guide baffle, a rotary kiln access pipe, a burner access pipe, an SNCR nozzle and a water tank. The beneficial effects are as follows: the device of the invention adopts a conventional SNCR reaction denitration device, which can achieve a denitration efficiency of 85%, has low operating costs, high adaptability, small footprint, low equipment height, and has a certain dust removal effect, saves 3% energy compared with conventional projects, has good sealing performance, is simple and easy to operate, has low investment cost, is suitable for the treatment of flue gas from the incineration of hazardous waste, and is particularly suitable for the treatment of flue gas from the incineration of hazardous waste rotary kilns with high concentrations of nitrogen oxides and high dust content.

Description

Technical Field

[0001] The invention relates to the technical field of hazardous waste incineration treatment, in particular to a secondary combustion chamber for hazardous waste incineration treatment. Background Art

[0002] During the incineration of hazardous waste, a large amount of NOx will be generated when burning high-nitro compounds. If the conventional SNCR denitrification method is used, the denitrification efficiency can only reach about 40%, and the flue gas will not be able to meet the emission standards. Therefore, SCR denitrification must be used to meet the flue gas emission requirements. However, the existing SCR mainly adopts the low-temperature SCR method and is set after the wet flue gas desulfurization. The construction cost and operating cost of SCR are much higher than the SNCR denitrification reaction device, and the construction of SCR requires a large site.

[0003] The secondary combustion chamber is a commonly used equipment for the incineration of hazardous waste. Since the internal temperature of the secondary combustion chamber is as high as 1100℃ and the external temperature is as low as 20-30℃, the large temperature difference will inevitably bring about a certain amount of heat loss. Reducing heat loss and saving energy are the consistent pursuits in the industry.

[0004] For conventional secondary combustion chambers, dust accumulation is easy to occur on the straight pipe connected to the waste heat boiler due to the influence of the outlet temperature drop, which often causes the production line to be shut down for maintenance and increases operating costs. This is an industry problem and an important task that the industry needs to solve urgently. Summary of the invention

[0005] In order to overcome the defects of the prior art, the technical problem solved by the present invention is to provide a secondary combustion chamber for the incineration of hazardous waste. The conventional SNCR reaction denitrification device is adopted, and the denitrification efficiency can reach 85%. The operation cost is low, the adaptability is high, the footprint is small, the equipment height is low, and it has a certain dust removal effect. Compared with conventional projects, it saves 3% energy, has good sealing performance, is simple and easy to operate, and has a low investment cost. It is suitable for the flue gas treatment of the incineration of hazardous waste, especially for the flue gas treatment of the rotary kiln incineration of hazardous waste with higher concentration of nitrogen oxides and higher dust content.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A secondary combustion chamber for incineration of hazardous waste, comprising an inner cylinder, an outer cylinder, a top cover, a slag outlet, a guide baffle, a rotary kiln access pipe, a burner access pipe, an SNCR nozzle and a water tank, characterized in that the inner cylinder is sleeved in the outer cylinder, the top cover is buckled on the upper ends of the inner cylinder and the outer cylinder, the slag outlet is arranged at the lower ends of the inner cylinder and the outer cylinder, and the inner cylinder and the outer cylinder are separated into two areas, the center of the inner cylinder is the combustion area, and the inner cylinder and the outer cylinder are between the cyclone separation and denitration reaction area; the rotary kiln access pipe passes through the outer cylinder and is connected to the inner cylinder, the upper part of the inner cylinder is provided with an inner air outlet connected to the cyclone separation and denitration reaction area; the guide baffle is arranged in the cyclone separation and denitration reaction area The upper part is adjacent to the inner air outlet and connected to the outer wall of the inner tube and the inner wall of the outer tube; an outgoing air outlet is provided on the top cover at the upper part of the cyclone separation and denitration reaction zone, adjacent to the guide baffle and away from the inner air outlet, and an emergency discharge chimney is provided at the center of the top cover, which is connected to the inner tube and the outgoing air outlet; there are several SNCR nozzles, facing the inner air outlet, arranged on the outer tube located 300 to 600 mm upstream of the flue gas flow of the inner air outlet, and a flue gas temperature measuring point is provided on the outer tube above the SNCR nozzle, and the temperature should be 1100°C; the burner access pipe is connected to the inner tube and the outer tube respectively; the water tank is arranged below the slag outlet.

[0008] The slag outlet is a double-layer sleeve structure with different diameters eccentric to the direction of the rotary kiln access pipe, the upper end of which is connected to the inner tube and the outer tube, and the lower end is immersed in the water in the water tank.

[0009] The water tank is provided with a water inlet at the top and a water outlet at the bottom. The water tank is also provided with a water temperature measuring point to control the water temperature in the water tank to be no higher than 60°C.

[0010] The inner cylinder and the outer cylinder are both cylindrical structures, all of which are built with refractory bricks, and the outer wall of the inner cylinder and the inner wall of the outer cylinder, that is, the inner wall of the cyclone separation and denitrification reaction area are rough inner walls.

[0011] The outer wall of the outer tube is covered with heat-insulating material to control the temperature of the outer wall to be less than 50°C.

[0012] The guide baffle is sprayed with wear-resistant castable material.

[0013] The burner access pipe is made of heat-resistant steel, and the outer wall is coated with insulation material and sprayed with refractory castables.

[0014] The rotary kiln access pipe is built with refractory bricks.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1) The present invention can adopt a conventional SNCR reaction denitration device, and the denitration efficiency can reach 85%;

[0017] 2) The present invention uses a conventional SNCR reaction device, so the operating cost is low;

[0018] 3) Compared with the independent secondary combustion chamber + cyclone separator, the present invention occupies less space, and compared with the traditional independent secondary combustion chamber, the building height is lower, and the construction cost is relatively low;

[0019] 4) The present invention has cyclone + inertia dual dust removal performance and high dust removal efficiency;

[0020] 5) The present invention solves the problem of ash accumulation in the horizontal flue at the outlet of the secondary combustion chamber;

[0021] 6) The present invention has excellent sealing performance;

[0022] 7) The present invention has a significant energy-saving effect, saving more than 3% of the energy consumption of the secondary combustion chamber and increasing the gas output of the waste heat boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the three-dimensional structural principle of the present invention.

[0024] In the figure: 1-inner tube 2-outer tube 3-top cover 4-slag outlet 5-smoke temperature measuring point 6-outlet 7-emergency discharge chimney 8-inner air outlet 9-flow guide baffle 10-rotary kiln access pipe 11-burner access pipe 12-SNCR nozzle 13-ventilation beam 14-water tank 141-water inlet 142-water outlet 143-water temperature measuring point DETAILED DESCRIPTION

[0025] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings:

[0026] See Figure 1As shown, the present invention relates to a secondary combustion chamber for incineration of hazardous waste, comprising an inner tube 1, an outer tube 2, a top cover 3, a slag outlet 4, a guide baffle 9, a rotary kiln access pipe 10, a burner access pipe 11, an SNCR nozzle 12 and a water tank 14, wherein the inner tube 1 is sleeved in the outer tube 2, the top cover 3 is buckled on the upper ends of the inner tube 1 and the outer tube 2, the slag outlet 4 is arranged at the lower ends of the inner tube 1 and the outer tube 2, and the inner tube 1 and the outer tube 2 are separated into two areas, the center of the inner tube 1 is the combustion area, and the area between the inner tube 1 and the outer tube 2 is the cyclone separation and denitration reaction area; the rotary kiln access pipe 10 passes through the outer tube 2 and is connected to the inner tube 1 (the connection method is rigid and closed, and there is no cross-flow between the inner tube 1 and the outer tube 2), the upper part of the inner tube 1 is provided with an inner air outlet 8 connected to the cyclone separation and denitration reaction area; the guide baffle 9 is arranged between the cyclone separation and denitration reaction area The upper part of the reaction zone is adjacent to the inner air outlet 8 and is connected to the outer wall of the inner tube 1 and the inner wall of the outer tube 2; the upper part of the cyclone separation and denitration reaction zone is adjacent to the guide baffle 9 and is provided with an outgoing air outlet 6 on the top cover 3 away from the inner air outlet 8, and an emergency discharge chimney 7 is provided at the center of the top cover 3, and the emergency discharge chimney 7 is connected with the inner tube 1 and the outgoing air outlet 6; the SNCR nozzles 12 are several, facing the inner air outlet 8, and are arranged on the outer tube 1 located 300 to 600 mm upstream of the flue gas flow of the inner air outlet 8, and a flue gas temperature measuring point 5 is provided on the outer tube 1 above the SNCR nozzle 12, and the temperature should be 1100°C; the burner access pipe 11 is connected to the inner tube 1 and the outer tube 2 respectively, and the connection method is rigid and closed, and there will be no cross-flow between the inner tube 1 and the outer tube 2; the water tank 14 is arranged below the slag outlet 4.

[0027] The slag outlet 4 is an eccentric reducing double-layer sleeve structure, eccentric to the direction of the rotary kiln access pipe 10, with the upper end connected to the inner tube 1 and the outer tube 2, and the lower end immersed in the water in the water tank 14, that is, water sealing is achieved.

[0028] The water tank 14 is provided with a water inlet 141 at the top and a water outlet 142 at the bottom. The water tank 14 is also provided with a water temperature measuring point 143 to control the water temperature in the water tank 14 to be no higher than 60°C.

[0029] The inner tube 1 and the outer tube 2 are both cylindrical structures, all of which are built with refractory bricks, and the outer wall of the inner tube 1 and the inner wall of the outer tube 2, that is, the inner wall of the cyclone separation and denitrification reaction area are rough inner walls.

[0030] The outer wall of the outer tube 2 is covered with heat-insulating material to control the outer wall temperature to be less than 50°C.

[0031] The guide baffle 9 is sprayed with wear-resistant castable material.

[0032] The burner access pipe 11 is made of heat-resistant steel, and its outer wall is coated with insulation material and sprayed with refractory castable.

[0033] The rotary kiln access pipe 10 is built with refractory bricks.

[0034] The device of the invention is located on a ventilation beam 13 of a steel structure, and the steel structure is coated with refractory material.

[0035] During operation, the flue gas from the rotary kiln enters the inner tube 1 from the rotary kiln access pipe 10, and is heated by the flame jet from the burner access pipe 11. The slag blocks fall down under the action of gravity and are discharged from the slag outlet 4. The flue gas flows upward along the central combustion area ( Figure 1 The flue gas enters the cyclone separation and denitration reaction zone from the inner air outlet 8 and reacts with the SNCR denitration agent from the SNCR nozzle 12. The slag blocks fall down under the action of gravity and are discharged from the slag outlet 4. The purified flue gas flows upward along the cyclone separation and denitration reaction zone in a spiral ( Figure 1 The air is discharged from the outlet 6 (the direction of the dotted arrow in the middle).

[0036] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A secondary combustion chamber for incineration of hazardous waste, comprising an inner cylinder, an outer cylinder, a top cover, a slag outlet, a guide baffle, a rotary kiln access pipe, a burner access pipe, an SNCR nozzle and a water tank, characterized in that: The inner cylinder is sleeved in the outer cylinder, the top cover is buckled on the upper ends of the inner cylinder and the outer cylinder, and the slag outlet is set at the lower ends of the inner cylinder and the outer cylinder, so that the inner cylinder and the outer cylinder are separated into two areas. The center of the inner cylinder is the combustion area, and the area between the inner cylinder and the outer cylinder is the cyclone separation and denitration reaction area; the rotary kiln access pipe passes through the outer cylinder and is connected to the inner cylinder, and the upper part of the inner cylinder is provided with an inner air outlet connected to the cyclone separation and denitration reaction area; the guide baffle is arranged at the upper part of the cyclone separation and denitration reaction area, close to the position of the inner air outlet and connected to the outer wall of the inner cylinder and the inner wall of the outer cylinder; the cyclone separation and An outgoing air outlet is provided on the top cover at the upper part of the denitration reaction zone, close to the guide baffle and away from the inner air outlet. An emergency discharge chimney is provided at the center of the top cover, and the emergency discharge chimney is connected with the inner tube and the outgoing air outlet. There are several SNCR nozzles, facing the inner air outlet, arranged on the outer tube located 300 to 600 mm upstream of the flue gas flow of the inner air outlet. A flue gas temperature measuring point is provided on the outer tube above the SNCR nozzle, and the temperature should be 1100°C. The burner access pipe is connected with the inner tube and the outer tube respectively. The water tank is arranged below the slag outlet.

2. A secondary combustion chamber for incineration of hazardous waste according to claim 1, characterized in that: The slag outlet is a double-layer sleeve structure with different diameters eccentric to the direction of the rotary kiln access pipe, the upper end of which is connected to the inner tube and the outer tube, and the lower end is immersed in the water in the water tank.

3. A secondary combustion chamber for incineration of hazardous waste according to claim 1, characterized in that: The water tank is provided with a water inlet at the top and a water outlet at the bottom. The water tank is also provided with a water temperature measuring point to control the water temperature in the water tank to be no higher than 60°C.

4. A secondary combustion chamber for incineration of hazardous waste according to claim 1, characterized in that: The inner cylinder and the outer cylinder are both cylindrical structures, all of which are built with refractory bricks, and the outer wall of the inner cylinder and the inner wall of the outer cylinder, that is, the inner wall of the cyclone separation and denitrification reaction zone, are rough inner walls.

5. The secondary combustion chamber for incineration of hazardous waste according to claim 1, characterized in that: The outer wall of the outer tube is covered with heat-insulating material to control the temperature of the outer wall to be less than 50°C.

6. A secondary combustion chamber for incineration of hazardous waste according to claim 1, characterized in that: The guide baffle is sprayed with wear-resistant castable material.

7. A secondary combustion chamber for incineration of hazardous waste according to claim 1, characterized in that: The burner access pipe is made of heat-resistant steel, and the outer wall is coated with insulation material and sprayed with refractory castables.

8. The secondary combustion chamber for incineration of hazardous waste according to claim 1, characterized in that: The rotary kiln access pipe is built with refractory bricks.

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