CN209909903U

CN209909903U - Low-oxygen flue gas internal reflux burner of chamber type heating furnace

Info

Publication number: CN209909903U
Application number: CN201920773840.XU
Authority: CN
Inventors: 李洪涛; 赵亚珊; 纪运广; 薛树旗; 盛永钢; 穆欣
Original assignee: Hebei University of Science and Technology
Current assignee: Hebei University of Science and Technology
Priority date: 2019-05-27
Filing date: 2019-05-27
Publication date: 2020-01-07
Anticipated expiration: 2029-05-27

Abstract

The utility model provides a backflow nozzle in low oxygen flue gas of room heating furnace, belongs to equipment for heat treatment technical field. The utility model discloses a method of back flow in low oxygen flue gas is through adding the flue gas with the back flow in the low oxygen flue gas, with low oxygen flue gas backward flow to the precombustion chamber in, can effectively reduce nitrogen oxide's emission. The utility model discloses a backflow nozzle in hypoxemia flue gas contains following part: a flue gas internal reflux pipe, a precombustion chamber, a Venturi tube, a gas pipe and an ignition device. One end of the smoke inner return pipe is connected with a position with lower oxygen concentration of the hearth, and the other end of the smoke inner return pipe is connected with the precombustion chamber; the gas pipe is used as an injection nozzle and is connected with the Venturi tube to inject the flue gas of the return pipe in the flue gas, so that the part of the flue gas is mixed into the fuel gas at the outlet of the Venturi tube. The utility model discloses the backward flow of low oxygen flue gas is realized to the pressure of the intraductal gas of rational utilization gas self, need not to increase extra consumption, can realize reducing the purpose that NOx discharged in the flue gas.

Description

Low-oxygen flue gas internal reflux burner of chamber type heating furnace

Technical Field

The utility model relates to a gas nozzle for heat accumulation formula heating furnace, concretely relates to backflow nozzle in chamber heating furnace's low oxygen flue gas, this backflow nozzle can realize high temperature low oxygen burning in the low oxygen flue gas, reaches the purpose that reduces NOx content in the flue gas, belongs to equipment for heat treatment technical field.

Technical Field

With the improvement of the living standard of people, the national requirements on environmental protection are more and more strict, and the requirements on kiln discharge are particularly strict. The regenerative burner can efficiently utilize waste heat of discharged smoke to achieve the effect of energy conservation, and is widely applied to the field of industrial kilns, but because the heat accumulator heats air to high temperature, the temperature of combustion flame is increased, so that the content of thermal NOx generated in the combustion process is increased, and the emission of overhigh content of nitrogen oxide increases the pollution to the environment. Therefore, it is necessary to technically control NOx emissions from combustion.

The flue gas internal reflux is used as a NOx control technology, and the technical key point is to reduce the oxygen content in the flue gas after combustion, thereby reducing the yield of NOx. Patent 201620082657.1 provides a take heat accumulation formula radiant tube nozzle of flue gas backward flow, and its draws and penetrates power and utilize the pressure energy of air, has not only increased the power consumption of fan, and the flue gas backward flow volume is difficult to control moreover. The patent 201810741652.9 provides a double-injection type low-nitrogen oxide combustion system of a regenerative heating furnace, wherein the tail end of a flue gas return pipe is connected to the vicinity of a venturi tube at an air outlet of a regenerative burner, and an air pipe is also used as a flue gas exhaust pipe, so that an injection device increases the resistance of flue gas exhaust, and the problem of difficulty in controlling the flow is solved, but the power consumption of the system is increased.

SUMMERY OF THE UTILITY MODEL

The utility model discloses it provides a backward flow nozzle in low oxygen flue gas of room formula heating furnace to plan for solve the high problem of flue gas NOx emission of the industrial kiln of current operation, especially be directed to room formula heating furnace.

The utility model discloses the technical scheme who specifically takes as follows:

the low-oxygen smoke internal reflux burner of the chamber type heating furnace is provided with a precombustion chamber, an outlet of the precombustion chamber is connected with a hearth of the chamber type heating furnace, an inlet of the precombustion chamber is connected with an outlet of a Venturi tube, an inlet of the Venturi tube is connected with an outlet of a gas tube and an outlet of a smoke internal reflux tube, and an inlet of the smoke internal reflux tube is connected with a lower oxygen concentration area in the hearth; the high-pressure fuel gas in the fuel gas pipe is sprayed into the pre-combustion chamber, and the Venturi tube performs suction action on the flue gas in the flue gas inner return pipe by means of the high pressure of the fuel gas, so that the flue gas inner return pipe can convey the gas with lower oxygen concentration in the hearth to the pre-combustion chamber; and an ignition device is fixedly arranged on the side wall of the precombustion chamber.

Further, still include the regenerator, the one end of regenerator with the precombustion chamber intercommunication, the other end of regenerator and the one end intercommunication of air pipe, in the other end of air pipe is connected with the air-blower.

Furthermore, a gas control valve is arranged on the gas pipe, and a flue gas control valve is arranged on the flue gas inner return pipe.

Compared with the prior art, the utility model has the advantages that:

the utility model discloses only need follow the lower department of furnace oxygen concentration and draw forth a flue gas internal reflux pipeline to venturi department, utilize the pressure of gas pipeline as the power supply, high-speed efflux forms low-pressure area, so need not additionally to add power device, can realize the flue gas backward flow, can save extra power device.

The utility model discloses a backflow nozzle is the heat accumulation formula nozzle in the hypoxemia, and the heat accumulation formula nozzle can be smoke exhaust apparatus and air inlet unit concurrently, the utility model discloses introduce as the example with air inlet unit. The scheme for realizing the overall design is as follows: the part with lower oxygen concentration in the hearth is led to the inlet of the Venturi tube through the flue gas inner return pipe, and the flue gas is mixed with the fuel gas and then sprayed into the hearth, so that the local oxygen content of the flame is reduced, and high-temperature low-oxygen combustion is realized. The utility model discloses utilize the pressure of gas pipeline as the power supply, need not additional power device, can realize the internal reflux to the flue gas.

Drawings

FIG. 1 is a schematic structural view of a low oxygen internal recirculation burner of a chamber furnace;

FIG. 2 is a schematic structural view of a low-oxygen internal reflux burner in a chamber furnace in an application state;

description of the figures

1. An air tube; 2. a regenerator; 3. a flue gas inner return pipe; 4. a venturi tube; 5. a gas pipe; 6. an ignition device; 7. A precombustion chamber; 8. a flue gas control valve; 9. a gas control valve; 10. a hearth; 11. an air blower.

Detailed Description

The invention will be further described with reference to the accompanying drawings and specific examples.

As shown in fig. 1-2, the utility model discloses a low oxygen flue gas internal reflux burner of chamber-type heating furnace includes: the heat storage chamber 2, the air pipe 1, the flue gas internal reflux pipe 3, the venturi pipe 4, the gas pipe 5, the ignition device 6 and the precombustion chamber 7.

The precombustion chamber 7 is a mixing part of air, smoke and fuel gas, the right end of the precombustion chamber 7, namely the inlet of the precombustion chamber 7, is connected with the outlet of the Venturi tube 4, an ignition device 6 is arranged on the side wall of the precombustion chamber 7 and close to the Venturi tube 4, and the left end of the precombustion chamber 7, namely the outlet of the precombustion chamber 7, is communicated with the hearth 10; the outlets of the fuel gas pipe 5 and the flue gas internal reflux pipe 3 are both connected with the inlet of the Venturi tube 4, and the initial end, namely the inlet, of the flue gas internal reflux pipe 3 is connected with the position with lower oxygen concentration in the hearth 10. High-pressure fuel gas in the fuel gas pipe 5 is sprayed into the pre-combustion chamber 7, and the venturi tube 4 performs a suction effect on the flue gas in the flue gas inner return pipe 3 by means of the high pressure of the fuel gas, so that the flue gas inner return pipe 3 can convey gas with lower oxygen concentration in the hearth 10 to the pre-combustion chamber 7; the upper end of the precombustion chamber 7 is connected with one end of a regenerative chamber 2, the other end of the regenerative chamber 2 is connected with an air pipe 1, and the other end of the air pipe 1 is provided with an air blower 11 relative to the end connected with the regenerative chamber 2.

The flue gas internal reflux pipe 3 is provided with a flue gas control valve 8, and the flow of the flue gas flowing through the flue gas internal reflux pipe 3 can be controlled by opening and closing the flue gas control valve 8; the gas pipe 5 is provided with a gas control valve 9 for controlling the flow rate of the gas flowing through the gas pipe 5.

As a preferred embodiment, the initial end of the flue gas internal reflux pipe 3 is connected to the lower oxygen concentration position of the hearth 10, the extracted flue gas is high-temperature and high-pressure flue gas which is not cooled after one round of combustion is finished, the high-temperature flue gas is extracted from the lower oxygen concentration position of the hearth to carry out flue gas reflux, so that the high-temperature flue gas can flow back to the precombustion chamber without adding any power, the power source of the high-temperature flue gas is the fuel gas of the fuel gas pipe 5, the fuel gas pipe 5 is connected with the venturi pipe as an injection nozzle, and a low-pressure environment is created by utilizing the accelerating injection principle of the venturi pipe to realize natural flue gas reflux, so that the mixing of air, fuel gas and flue gas in the precombustion chamber is accelerated.

The utility model discloses be applied to room formula heating furnace's theory of operation: firstly, opening a gas control valve 9 and a smoke control valve 8, introducing air into an air pipe 1 from an air blower 3, and enabling the air to pass through a regenerative chamber 2, be preheated and then enter a precombustion chamber 7; the gas gets into precombustion chamber 7 through gas pipe 5, venturi 4, along with the gas gets into venturi 4, the flue gas mixes with the gas in venturi 4 through return pipe 3 in the flue gas, get into precombustion chamber 7 jointly, wherein the flue gas that return pipe 3 extracted in the flue gas is the high temperature flue gas of the lower department of furnace 10 oxygen concentration after a round of burning finishes, in this working process, utilize the low pressure that the special structure of venturi 4 and gas pipe 5 formed, make the flue gas reflux and mix with the gas entering precombustion chamber 7 of the lower oxygen concentration in furnace 10, reentrant furnace 10.

The utility model discloses a low oxygen flue gas internal reflux nozzle of room formula heating furnace, 7 departments in the precombustion chamber, carry out the air, the intensive mixing of gas and high temperature flue gas, form the condition of igniteing, wherein the mixture of high temperature flue gas and oxygen, can preheat the mixed air, reduce the content of oxygen when firing the temperature, the production of the nitrogen oxide that significantly reduces, reach the effect of environmental protection, after the burning, the high temperature flue gas is through precombustion chamber 7, regenerator 2 and air pipe 1 discharge, wait for the burning of next round, wherein, the heat of flue gas can be stored and preheat the air of next set of burning in the regenerator, thereby reach energy-conserving effect, this is a round of circulation promptly, the heat accumulation nozzle alternate operation of symmetrical arrangement during the operation, but make full use of flue gas waste heat.

The above description is only the basic embodiment of the present invention, and it should be noted that: all the improvements and decorations made within the spirit and principle of the present invention should be considered as the protection scope of the present invention without departing from the principle of the present invention.

Claims

1. The low-oxygen smoke internal reflux burner of the chamber type heating furnace is characterized by comprising a precombustion chamber (7), wherein an outlet of the precombustion chamber (7) is connected with a hearth (10) of the chamber type heating furnace, an inlet of the precombustion chamber (7) is connected with an outlet of a Venturi tube (4), an inlet of the Venturi tube (4) is connected with an outlet of a gas pipe (5) and an outlet of a smoke internal reflux pipe (3), and an inlet of the smoke internal reflux pipe (3) is connected to a region with lower oxygen concentration in the hearth (10); high-pressure fuel gas in the fuel gas pipe (5) is sprayed into the pre-combustion chamber (7), and the Venturi tube (4) forms a suction effect on the flue gas in the flue gas inner return pipe (3) by means of the high pressure of the fuel gas, so that the flue gas inner return pipe (3) can convey the gas with lower oxygen concentration in the hearth (10) to the pre-combustion chamber (7); an ignition device (6) is fixedly arranged on the side wall of the precombustion chamber (7).

2. The low-oxygen flue gas internal reflux burner of the chamber heating furnace as claimed in claim 1, wherein: still include regenerator (2), the one end of regenerator (2) with precombustion chamber (7) intercommunication, the other end of regenerator (2) and the one end intercommunication of air pipe (1), in the other end of air pipe (1) is connected with air-blower (11).

3. The low-oxygen flue gas internal reflux burner of the chamber heating furnace as claimed in claim 1, wherein: a gas control valve (9) is arranged on the gas pipe (5), and a flue gas control valve (8) is arranged on the flue gas inner return pipe (3).