Direct-fired heat compensation device for flue gas denitration

Abstract

The utility model relates to a direct combustion type heat compensation device for flue gas denitration, which comprises a flue gas pipeline, a combustor arranged on the outer side of the middle of the flue gas pipeline, a fuel gas inlet and a combustion-supporting air inlet arranged at the outer end of the combustor, a combustion-supporting fan connected with the outer end of the combustion-supporting air inlet, a flame jet orifice arranged at the inner end of the combustor, and a windshield arranged on the flue gas upstream of the flame jet orifice. A homogenizing air mixing mechanism is arranged on the downstream portion of the smoke of the flame jet orifice and used for diffusing the smoke heated by the flame in the smoke pipeline in the radial direction. According to the utility model, the combustor is directly arranged on the flue gas pipeline to directly heat the flue gas in the pipeline, and a heat compensation mode of a heat compensation furnace and a heat exchanger is replaced, so that the energy efficiency is greatly improved, and the investment cost and the operation cost are greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of flue gas furnaces, in particular to a direct-fired heat supplement device for flue gas denitration. Background Art

[0002] When heating materials in industrial production, flue gas is generated. The flue gas generated by some materials contains NOx, which pollutes the environment. Therefore, the flue gas needs to be denitrified before being discharged. The existing denitrification process requires the flue gas temperature to reach above 280°C. The temperature of some heating furnaces is not high during production. There is also a section of pipeline from the outlet of the heating furnace to the denitrification system to transport the flue gas. This makes the flue gas temperature reaching the denitrification system less than 280°C, which has an adverse effect on the denitrification effect. In order to solve this problem, some manufacturers currently set up a supplementary heating furnace at the pipeline for transporting flue gas to generate high-temperature gas for heat exchange with the flue gas, so as to achieve the purpose of supplementary heating of the flue gas and make the flue gas temperature entering the denitrification system reach above 280°C; although this treatment method achieves the purpose, it requires the investment of supplementary heating furnaces, heat exchangers and other facilities, with high investment costs, and the supplementary heating furnace itself consumes a lot of energy, and the heat exchange efficiency between the high-temperature gas and the flue gas is not high, which increases the operating cost. Summary of the invention

[0003] The purpose of the utility model is to solve the problems existing in the above-mentioned prior art and to provide a direct-fired heat supplement device for flue gas denitrification.

[0004] The specific scheme of the utility model is: a direct-fired heating device for flue gas denitrification, including a flue gas duct, a burner is installed on the outer side of the middle part of the flue gas duct, a gas inlet and a combustion-supporting air inlet are arranged at the outer end of the burner, a combustion-supporting fan is connected to the outer end of the combustion-supporting air inlet, a flame injection port is arranged at the inner end of the burner, a wind shield is arranged upstream of the flame injection port, a homogenizing air mixing mechanism is arranged downstream of the flame injection port, and the homogenizing air mixing mechanism is used to diffuse the flue gas heated by the flame radially in the flue gas duct.

[0005] Furthermore, the output end of the combustion-supporting fan is connected to the combustion-supporting air inlet of the burner, and the input end of the combustion-supporting fan is provided with two air inlet pipes, one end of which is connected to the inside of the flue gas duct, and a flue gas valve is installed on the air inlet pipe A, and the other air inlet pipe B is connected to the outside air, and an air valve is installed on the air inlet pipe B.

[0006] Furthermore, the homogenized air mixing mechanism includes a V-shaped air guide plate, and the wind shield includes an arc-shaped baffle.

[0007] Furthermore, there are a plurality of burners, and the burners arranged on both sides of the flue gas duct are staggered with each other.

[0008] Furthermore, the width of one side of the V-shaped air guide plate facing the center line is greater than that of the other side.

[0009] Furthermore, a control valve is installed on the air inlet pipe, and a temperature sensor is provided at the upper end of the flue gas duct. The temperature sensor is connected to a PLC controller, and the PLC controller is connected to the control valve signal.

[0010] The utility model has the following beneficial effects: 1. By directly arranging a burner on the flue gas duct, the flue gas in the duct is directly heated, replacing the heating method of the heating furnace and the heat exchanger, thereby greatly improving the energy efficiency and greatly reducing the investment cost and the operating cost; 2. A wind shield is arranged to protect the flame to avoid being blown out by the flue gas, and a homogenizing air mixing mechanism is arranged so that the high-temperature flue gas after combustion is fully mixed with the low-temperature flue gas in the duct, so as to achieve the purpose of uniformly raising the temperature of the mixed flue gas and meet the requirements of the denitrification system; 3. The fan directly draws oxygen-containing flue gas from the flue gas duct as combustion-supporting air, thereby improving the combustion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is the front view of the utility model;

[0012] Figure 2 It is a top view of the utility model;

[0013] Figure 3 yes Figure 2 BB view;

[0014] In the figure: 1. Flue gas duct; 2. Gas valve; 3. Fan; 4. Homogenizing and mixing air mechanism; 5. Burner; 6. Wind shield; 7. Flue gas valve; 8. Air valve; 9. Center line of flue gas duct. DETAILED DESCRIPTION

[0015] Embodiment 1

[0016] See also Figure 1-3 The present embodiment is a direct-fired supplementary heat device for flue gas denitrification, comprising a flue gas duct 1 arranged in a vertical direction, the flue gas flow direction in the flue gas duct 1 is from bottom to top, so the lower end of the flue gas duct 1 is upstream and the upper end is downstream, the upper end outlet of the flue gas duct 1 is connected to the denitrification system, a burner 5 is installed on the outer side of the middle part of the flue gas duct 1, a gas inlet and a combustion-supporting air inlet are arranged at the outer end of the burner 5, a gas pipe is connected to the outer end of the gas inlet, a gas valve 2 is installed on the gas pipe, a combustion-supporting fan 3 is connected to the outer end of the combustion-supporting air inlet, a flame injection port is provided at the inner end of the burner 5, a wind shield 6 is provided below the flame injection port, a homogenizing air mixer 3 is provided above the flame injection port, and the homogenizing air mixer 3 is used to diffuse the flue gas heated by the flame laterally in the flue gas duct 1.

[0017] Furthermore, the output end of the combustion-supporting fan 3 is connected to the combustion-supporting air inlet of the burner 5, and the input end of the combustion-supporting fan 3 is provided with two air inlet pipes, one end of which is connected to the inside of the flue gas duct 1, and a flue gas valve 7 is installed on the air inlet pipe A, and the other air inlet pipe B is connected to the outside air, and an air valve 8 is installed on the air inlet pipe B; a temperature sensor is provided at the upper end of the flue gas duct 1 near the denitrification system, and the temperature sensor is connected to the PLC controller, and the PLC controller is connected to the flue gas valve 7 and the air valve 8 by signal; the temperature of the flue gas entering the denitrification system is detected in real time by the temperature sensor, and the lower limit of the temperature is set to 280°C. If the actual temperature is lower than 280°C, the PLC controller automatically controls the opening of the flue gas valve 7 and the air valve 8 to increase, thereby increasing the heating rate and increasing the flue gas heating rate. When the actual temperature is higher than 280°C, the current valve opening is maintained.

[0018] Furthermore, the homogenizing air mixer 3 includes an air guide plate with a V-shaped cross-section, one end of the V-shaped air guide plate is connected to the inner wall of the flue gas duct 1, and the other end extends toward the center of the duct. The wind shield 6 includes an arc-shaped baffle, one end of the arc-shaped baffle is connected to the inner wall of the flue gas duct 1, and the other end extends toward the center of the duct, but the length of the arc-shaped baffle is smaller than the air guide plate. During actual operation, the extended length of the arc-shaped baffle is smaller than the length of the flame.

[0019] Furthermore, there are a plurality of burners 5 , and the burners 5 arranged on both sides of the flue gas duct 1 are staggered with each other, and the burners 5 on both sides are arranged on both sides of the center line 9 of the flue gas duct respectively.

[0020] Furthermore, the width L1 of the V-shaped air guide plate on one side facing the center line 9 of the flue gas pipe is greater than the width L2 on the other side. The purpose of this arrangement is to guide the burnt high-temperature flue gas to the side of the flue gas pipe so that the high-temperature flue gas and the low-temperature flue gas are fully mixed.

[0021] The working principle of the utility model is as follows: after the burner 5 is ignited, under the protection of the wind shield 6, the flame can avoid the interference of the flue gas flow rate to form a stable torch, and the flame is maintained to burn at a temperature below 950°C by adjusting the flue gas valve 7 and the air valve 8. The oxygen content in the flue gas is about 15-20%, so the fan 3 extracts the flue gas in the flue gas duct 1 and supplements it with natural air from the outside as combustion-supporting wind for continuous combustion.

[0022] The high-temperature flue gas after combustion is fully mixed with the low-temperature flue gas in the flue gas duct 1 under the guidance of the homogenizing mixer 3, so that the temperature of the mixed flue gas is raised to above 280°C before entering the denitrification system. Before entering the denitrification system, the temperature of the mixed flue gas is detected in real time by a temperature sensor and automatically adjusted by the PLC controller, thereby ensuring the normal operation of the flue gas heating and achieving the design purpose.

[0023] Embodiment 2

[0024] The structure of this embodiment is basically the same as that of the first embodiment, except that the flue gas duct 1 is arranged horizontally or inclined to the horizontal direction, the wind shield 6 is arranged upstream of the flue gas flow of the flame injection port, and the homogenizing and mixing air mechanism 4 is arranged downstream of the flame injection port.

Claims

1. A direct-fired supplementary heat device for flue gas denitrification, comprising a flue gas duct, characterized in that: A burner is installed on the outer side of the middle part of the flue gas duct, and a gas inlet and a combustion-supporting air inlet are arranged at the outer end of the burner. The outer end of the combustion-supporting air inlet is connected to a combustion-supporting fan. A flame injection port is arranged at the inner end of the burner, a wind shield is arranged upstream of the flame injection port, and a homogenizing air mixing mechanism is arranged downstream of the flame injection port. The homogenizing air mixing mechanism is used to diffuse the flue gas heated by the flame radially in the flue gas duct.

2. The direct-fired supplementary heat device for flue gas denitrification according to claim 1 is characterized in that: The output end of the combustion-supporting fan is connected to the combustion-supporting air inlet of the burner, and the input end of the combustion-supporting fan is provided with two air inlet pipes, one end of which is connected to the inside of the flue gas duct, and a flue gas valve is installed on the air inlet pipe A, and the other air inlet pipe B is connected to the outside air, and an air valve is installed on the air inlet pipe B.

3. The direct-fired supplementary heat device for flue gas denitrification according to claim 1 is characterized in that: The homogenizing and mixing air mechanism comprises a V-shaped air guide plate, and the wind shield comprises an arc-shaped baffle plate.

4. The direct-fired supplementary heat device for flue gas denitrification according to claim 3 is characterized in that: There are a plurality of burners, and the burners arranged on both sides of the flue gas duct are staggered with each other.

5. The direct-fired supplementary heat device for flue gas denitrification according to claim 4 is characterized in that: The width of one side of the V-shaped air guide plate facing the center line is greater than that of the other side.

6. The direct-fired supplementary heat device for flue gas denitration according to claim 2 is characterized in that: A control valve is installed on the air inlet pipe, and a temperature sensor is provided at the upper end of the flue gas pipe. The temperature sensor is connected to a PLC controller, and the PLC controller is connected to the control valve signal.

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