CN212902710U

CN212902710U - Coal gas combustion-supporting structure in sintering flue gas denitration system

Info

Publication number: CN212902710U
Application number: CN202022046273.3U
Authority: CN
Inventors: 王睿; 冯茂荣
Original assignee: Pangang Group Panzhihua Steel and Vanadium Co Ltd
Current assignee: Pangang Group Panzhihua Steel and Vanadium Co Ltd
Priority date: 2020-09-17
Filing date: 2020-09-17
Publication date: 2021-04-06
Anticipated expiration: 2030-09-17

Abstract

The utility model discloses a metallurgical technical field's a combustion-supporting structure of coal gas among sintering flue gas denitration system, the combustion-supporting structure of coal gas among the sintering flue gas denitration system, include the fire tube way and the play tobacco pipe way of advancing that link to each other with denitrification facility, rotary heat exchanger to and the coal gas pipeline who links to each other with advancing the fire tube way, the exit linkage of coal gas pipeline has the air duct, and is equipped with the admission valve on the air duct be equipped with a smoke return pipe on advancing the fire tube way at rotary heat exchanger rear and link to each other with the export of coal gas pipeline, be equipped with the fan on the smoke return pipe, the air-blast direction of fan is from advancing the fire tube way to coal gas pipeline. Further, the fan is a variable-frequency speed-regulating fan. The high-temperature flue gas after the rotary heat exchanger is introduced into the gas pipeline to serve as combustion-supporting gas of the gas, and air is used for supplementary combustion supporting only under the condition of abnormal air quantity and oxygen content, so that on one hand, the temperature of the combustion-supporting gas is high, the use amount of the sintering flue gas denitration system for heating the gas can be effectively reduced, and on the other hand, part of carbon monoxide in the flue gas can be combusted simultaneously, and the carbon emission amount in the discharged flue gas of the sintering machine is reduced.

Description

Coal gas combustion-supporting structure in sintering flue gas denitration system

Technical Field

The utility model relates to a metallurgical technology field especially relates to a combustion-supporting structure of coal gas among sintering flue gas denitration system.

Background

The metallurgy sintering flue gas denitration is generally carried out by an SCR (selective catalytic reduction) method at present, and the reaction temperature required by the SCR denitration process is generally over 280 ℃. The sintering flue gas generally can not directly meet the temperature requirement, and the flue gas is required to be heated before denitration. Because of the byproduct gas of the metallurgical enterprise, the sintering flue gas denitration system generally considers that the self-produced gas of the metallurgical enterprise is used for heating the flue gas before denitration, and simultaneously, external air is introduced for gas combustion supporting. This approach suffers mainly from two disadvantages: 1. the temperature of air introduced from the outside is relatively low, and the coal gas consumption is increased when the flue gas is heated; 2. the sintering flue gas contains about 1% of carbon monoxide, and the carbon emission is increased without combustion and emission.

SUMMERY OF THE UTILITY MODEL

For overcoming the above-mentioned not enough that the combustion-supporting mode of current coal gas exists, the utility model aims to solve the technical problem that: the gas combustion-supporting structure in the sintering flue gas denitration system can reduce the gas consumption and the carbon emission.

The utility model provides a technical scheme that its technical problem adopted is:

the gas combustion-supporting structure in the sintering flue gas denitration system comprises a gas inlet pipeline and a gas outlet pipeline which are connected with a denitration device and a rotary heat exchanger, and a gas pipeline connected with the gas inlet pipeline, wherein an outlet of the gas pipeline is connected with an air pipeline, an air inlet valve is arranged on the air pipeline, a smoke return pipe is arranged on the gas inlet pipeline behind the rotary heat exchanger and is connected with an outlet of the gas pipeline, a fan is arranged on the smoke return pipe, and the air blowing direction of the fan is from the gas inlet pipeline to the gas pipeline.

Further, the fan is a centrifugal fan.

Furthermore, a control valve is arranged on the smoke return pipe, and the control valve is positioned on the section of smoke return pipe between the fan and the smoke inlet pipe.

Furthermore, the air pipeline is connected with the smoke returning pipe, and the connecting part is positioned on the section of smoke returning pipe between the fan and the smoke inlet pipeline.

Furthermore, the air inlet valve and the control valve are provided with flow and oxygen content monitoring functions.

The utility model has the advantages that: the high-temperature flue gas after the rotary heat exchanger is introduced into the gas pipeline to serve as combustion-supporting gas of the gas, and air is used for supplementary combustion supporting only under the condition of abnormal air quantity and oxygen content, so that on one hand, the temperature of the combustion-supporting gas is high, the use amount of the sintering flue gas denitration system for heating the gas can be effectively reduced, and on the other hand, part of carbon monoxide in the flue gas can be combusted simultaneously, and the carbon emission amount in the discharged flue gas of the sintering machine is reduced.

Drawings

Fig. 1 is a schematic structural diagram of a first embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a second embodiment of the present invention.

Marked in the figure as 1-denitration device, 2-gas pipeline, 3-air pipeline, 4-smoke returning pipe, 5-rotary heat exchanger, 6-burner, 11-smoke inlet pipeline, 12-smoke outlet pipeline, 31-air inlet valve, 41-fan and 42-control valve.

Detailed Description

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

The first embodiment is as follows:

as shown in fig. 1, the gas combustion-supporting structure in the sintering flue gas denitration system includes a flue gas inlet pipe 11 and a flue gas outlet pipe 12 connected to a denitration device 1 and a rotary heat exchanger 5, and a gas pipeline 2 connected to the flue gas inlet pipe 11, an air pipeline 3 is connected to an outlet of the flue gas inlet pipe 11 of the gas pipeline 2, an air inlet valve 31 is disposed on the air pipeline 3, a flue gas return pipe 4 is disposed on the flue gas inlet pipe 11 behind the rotary heat exchanger 5 and connected to an outlet of the flue gas pipeline 2, a fan 41 is disposed on the flue gas return pipe 4, and a blowing direction of the fan 41 is from the flue gas inlet pipe 11 to the gas pipeline 2. The fan 41 is used for sucking part of hot flue gas from the flue gas inlet pipe 11 as combustion-supporting gas, heating the gas entering from the gas pipe 2 and the air entering from the air pipe 3, and by controlling the amount of flue gas entering the gas pipe 2, the heated combustion-supporting gas and the gas are combusted at the combustor 6 so that the flue gas in the flue gas inlet pipe 11 is further heated before entering the denitration device 1.

The traditional gas combustion-supporting structure only introduces external air as combustion-supporting gas of gas through the air pipeline 3, and the external air is mixed with the gas and then is combusted in the smoke inlet pipeline 11, so that sintering smoke in the smoke inlet pipeline 11 is heated. Because the outside air temperature is relatively low, the coal gas consumption can be increased when the flue gas is heated, and in addition, the sintering flue gas contains about 1 percent of carbon monoxide, and the carbon emission can be increased when the carbon monoxide is not combusted and discharged.

After the improvement, part of high-temperature flue gas after the rotary heat exchanger 5 is introduced into the gas pipeline 2 by the smoke return pipe 4 and the fan 41 to serve as combustion-supporting gas, and the sintering flue gas contains certain oxygen, so that the combustion-supporting effect can be achieved. Meanwhile, according to actual conditions, a small amount of air can be blown in through the original air pipeline 3 to ensure the oxygen content of the combustion-supporting gas. In the mode, the combustion-supporting gas temperature is high, so that the amount of coal gas heated by the sintering flue gas denitration system can be effectively reduced, and on the other hand, part of carbon monoxide in the flue gas can be combusted simultaneously, so that the carbon emission amount in the externally-discharged flue gas of the sintering machine is reduced.

Further, in order to ensure that the denitrated flue gas can stably enter the gas pipeline 2 and facilitate controlling the flow rate of the flue gas, the fan 41 preferably adopts a centrifugal fan with adjustable speed.

In addition, for the convenience of control, a control valve 42 is further provided on the smoke return pipe 4, and the control valve 42 is located on the section of the smoke return pipe 4 between the fan 41 and the smoke outlet pipe 12. The control valve 42 can cut off the smoke returning pipe 4, so that the equipment is convenient to overhaul and maintain, and meanwhile, the fan 41 can be assisted to perform backflow control on high-temperature smoke.

Example two:

as shown in fig. 2, the structure is a further improvement of the first embodiment, the air pipe 3 directly connected to the gas pipe 2 is changed to be connected to the smoke return pipe 4, and the connection part is arranged on the section of smoke return pipe 4 between the blower 41 and the smoke outlet pipe 12. The further effect that this structure can bring is that can utilize fan 41 to realize flue gas backward flow and the introduction of outside air simultaneously, need not be like current equipment need be equipped with a blast apparatus for air duct 3 alone. Through the control of the air inlet valve 31 on the air pipeline 3 and the control valve 42 on the smoke return pipe 4, the oxygen content of the combustion-supporting gas is ensured, and meanwhile, the external air and the denitration flue gas are uniformly mixed, so that the continuous and stable combustion of the coal gas is ensured.

Further, in order to facilitate the explicit control of the intake valve 31 and the control valve 42, the intake valve 31 and the control valve 42 are preferably valves with flow and oxygen monitoring functions, so as to facilitate the operator to intuitively know and control the gas flow.

According to the embodiment of the utility model, the high temperature flue gas behind the rotary heat exchanger 5 is adopted as the combustion-supporting gas of coal gas, only supplements a small amount of air as the combustion-supporting gas of coal gas under the amount of wind and the oxygen content abnormal conditions. Through detection, compared with the existing combustion-supporting structure, the method can reduce the coal gas consumption of a sintering flue gas denitration system by about 15 percent and reduce the carbon emission of a sintering machine by about 5 percent, and can bring better economic and social values.

Claims

1. Combustion-supporting structure of coal gas among sintering flue gas deNOx systems, including advance tobacco pipe way (11) and go out tobacco pipe way (12) that link to each other with denitrification facility (1), rotary heat exchanger (5) to and coal gas pipeline (2) that link to each other with advancing tobacco pipe way (11), coal gas pipeline (2) exit linkage has air duct (3) to be equipped with admission valve (31), characterized by on air duct (3): a smoke return pipe (4) is arranged on the smoke inlet pipeline (11) behind the rotary heat exchanger (5) and connected with an outlet of the gas pipeline (2), a fan (41) is arranged on the smoke return pipe (4), and the blowing direction of the fan (41) is from the smoke inlet pipeline (11) to the gas pipeline (2).

2. The gas combustion-supporting structure in the sintering flue gas denitration system of claim 1, which is characterized in that: the fan (41) is a centrifugal fan.

3. The gas combustion-supporting structure in the sintering flue gas denitration system of claim 1, which is characterized in that: the smoke return pipe (4) is provided with a control valve (42), and the control valve (42) is positioned on the section of the smoke return pipe (4) between the fan (41) and the smoke inlet pipe (11).

4. The gas combustion-supporting structure in the sintering flue gas denitration system of claim 3, characterized in that: the air pipeline (3) is connected with the smoke returning pipe (4), and the connecting part is positioned on the section of the smoke returning pipe (4) between the fan (41) and the smoke inlet pipeline (11).

5. The gas combustion-supporting structure in the sintering flue gas denitration system of claim 4, characterized in that: the air inlet valve (31) and the control valve (42) are provided with flow and oxygen content monitoring functions.