A heat storage type organic waste gas combustion device and combustion method

Abstract

The present invention discloses a heat storage type organic waste gas combustion device, comprising a furnace, a first burner and a second burner of the same structure are arranged at the bottom of the furnace, a first heat storage body and a second heat storage body are arranged at the outlets of the first burner and the second burner in the furnace correspondingly, a heat insulation wall is arranged between the first heat storage body and the second heat storage body, the heat insulation wall separates the first heat storage body and the second heat storage body, a combustion chamber for conducting the first heat storage body and the second heat storage body is provided above the heat insulation wall in the furnace, air inlets are provided on the first burner and the second burner, and during the heat storage combustion process, the air inlet of one of the burners is used as an exhaust channel; the present invention utilizes the conical area of the channel outlet to accelerate the gas, avoids the blockage of the channel by dust droplets, and avoids flash explosion; utilizes the heat storage body to absorb flue gas energy, preheats the secondary air, reduces energy loss, and improves the waste gas incineration effect.

Description

Technical Field

[0001] The present invention relates to the technical field of volatile organic compounds (VOCs) treatment, and in particular to a heat storage type organic waste gas combustion device and a combustion method. Background Art

[0002] VOCs waste gas has a complex composition and varying toxicity, primarily consisting of benzene, hydrocarbons, alcohols, and aldehydes. If discharged without treatment, they pose serious risks to the atmospheric environment and human health. Existing VOCs treatment methods with high efficiency include thermal storage combustion and direct thermal oxidation. Thermal storage combustion is suitable for high-volume, low-concentration waste gas, while direct thermal oxidation is suitable for high-concentration waste gas.

[0003] While regenerative combustion technology offers significant energy savings, it places strict controls on the concentration and type of organic compounds (VOCs) in the inlet exhaust gas. When the VOC concentration exceeds 25% of the lower explosion limit, the exhaust gas is stopped from entering the combustion treatment device and is vented directly through a bypass, causing direct discharge of the exhaust gas to pollute the environment. Changes in the type of inlet VOCs often cause deviations in the detection value of the combustible lower explosion limit, resulting in excessive VOC concentrations entering the combustion device, making it very easy for flash explosions to occur within the device. Existing regenerative burners also have difficulty handling dust and droplets entrained in the exhaust gas, which can easily clog the gas passages of the regenerative body and cause shutdowns. Summary of the Invention

[0004] Technical purpose: In view of the fact that existing heat storage burners are prone to flash explosion when the inlet concentration changes, and the dust and droplets entrained in the exhaust gas are prone to insufficient blockage of the gas channel, the present invention discloses a heat storage type organic waste gas combustion device and combustion method that does not have the risk of backfire flash explosion, allows the exhaust gas to carry dust and droplets, and can handle a variety of exhaust gas working conditions.

[0005] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:

[0006] A heat storage type organic waste gas combustion device includes a furnace, a first burner and a second burner with the same structure are arranged at the bottom of the furnace, a first heat storage body and a second heat storage body are arranged at the outlets of the first burner and the second burner in the furnace respectively, an insulation wall is provided between the first heat storage body and the second heat storage body, the insulation wall separates the first heat storage body and the second heat storage body, a combustion chamber for connecting the first heat storage body and the second heat storage body is provided above the insulation wall in the furnace, and gas flows between the first heat storage body and the second heat storage body through the combustion chamber; air inlets are provided on both the first burner and the second burner, and during the heat storage combustion process, the air inlet of one of the burners is used as an exhaust channel.

[0007] Preferably, the first burner of the present invention includes a burner body, an auxiliary combustion gas channel is provided at the inlet end of the burner body, and a primary air channel is concentrically provided outside the auxiliary combustion gas channel; an organic waste gas channel is concentrically provided outside the primary air channel, and the channel outlet located in the inner circle is lower than the channel outlet located in the outer circle; the auxiliary combustion gas, primary air and organic waste gas converge at the outlet end of the organic waste gas channel and flow to a premixing chamber connected to the organic waste gas channel, and are mixed in the premixing chamber; the premixing chamber adopts a funnel-shaped structure, and an airflow distribution orifice plate connected to the furnace is provided at the top of the premixing chamber, and air holes are provided on the airflow distribution orifice plate, and the mixed gas enters the furnace from the air holes.

[0008] Preferably, the outlet ends of the combustion-supporting gas channel, the primary air channel, and the organic waste gas channel of the present invention all adopt a tapered structure with gradually decreasing diameters.

[0009] Preferably, the burner body of the present invention is provided with a secondary air channel outside the organic waste gas channel, the secondary air channel surrounds the outside of the organic waste gas channel and the premixing chamber, and a secondary air nozzle connected to the secondary air channel is provided on the premixing chamber.

[0010] Preferably, the secondary air nozzles of the present invention are evenly distributed along the central circumference of the premixing chamber, and the air holes correspond to the secondary air nozzles; a third heat storage body is arranged at the air inlet end of the secondary air channel, and the third heat storage body stores heat when the secondary air channel is used as an exhaust channel.

[0011] Preferably, the present invention is lined with insulation material in the secondary air channel to insulate the preheated secondary high-temperature air, and a temperature sensor is set in the secondary air channel. The temperature sensor is electrically connected to the control system for controlling the state switching of the first burner and the second burner.

[0012] The present invention also provides a combustion method based on the above-mentioned thermal storage type organic waste gas combustion device. It includes the following steps:

[0013] S01. First, gas premixing is performed. Combustion gas, primary air, organic waste gas and secondary air enter the premixing chamber from the upper channel of the first burner and are fully mixed in the premixing chamber.

[0014] S02, then a combustion is carried out, and the premixed gas enters the first combustion body of the furnace through the air holes on the air flow distribution plate and burns.

[0015] S03, the flue gas generated by the combustion in the first heat storage body enters the combustion chamber from the first heat storage body under the heat conduction effect of the heat insulation wall, and then flows back from the top of the combustion chamber into the second heat storage body for secondary combustion;

[0016] S04, then performing flue gas heat storage. The flue gas after secondary combustion in the second heat storage body enters the premixing chamber of the second burner through the air holes, and flows back through the third heat storage tank of the second burner from the secondary air nozzle. The third heat storage tank of the second burner absorbs heat from the flue gas to store heat.

[0017] S05. Finally, the temperature sensor detects the flue gas temperature. When the temperature reaches the set value, the third heat accumulator of the second burner completes heat storage. The control system controls the combustion state switching, and the second burner supplies gas for combustion, and the flue gas is discharged from the secondary air channel of the first burner.

[0018] Preferably, in step S01, the combustion-supporting gas and primary air of the first burner are accelerated through their respective channel outlets, and then gathered with the organic waste gas at the outlet of the organic waste gas channel to form a primary premixed gas, which is then accelerated again and enters the premixing chamber. The secondary air enters the premixing chamber from the secondary air channel of the first heat exchanger, and is disturbed and mixed by the primary premixed gas to form a secondary premixed gas.

[0019] Preferably, in step S04, when the secondary air channel of the second burner is used as the exhaust channel, the combustion-supporting gas channel, the organic waste gas channel and the primary air channel of the second burner are closed, and the channel outlet pressure is greater than the secondary air channel pressure of the second burner.

[0020] Beneficial effects: The combustion method of the heat storage type organic waste gas combustion device provided by the present invention has the following beneficial effects:

[0021] 1. The present invention sets a third heat accumulator in the secondary air channel of the burner to store heat during exhaust. When serving as an air inlet, it preheats the incoming secondary air. The exhaust temperature is 150-180°C. The stored heat is used to preheat the combustion air. The comprehensive thermal efficiency is greater than 80%, the combustion gas consumption is low, and the energy saving effect is significant.

[0022] 2. The present invention preheats the incoming secondary air through the third heat accumulator, reducing the heat loss in the furnace. The exhaust gas combustion temperature is ≥1100°C, and the incineration treatment of difficult-to-decompose substances such as benzene series and aromatic hydrocarbons in the VOCs exhaust gas is more thorough.

[0023] 3. The outlets for organic waste gas, primary air, and combustion-supporting gas in this invention all adopt a tapered structure, with the inner ring outlet lower than the outer ring outlet. The combustion-supporting gas is accelerated three times before entering the premixing chamber for mixing. The velocity at the burner outlet reaches 90-120 m / s, far exceeding the flame propagation speed, eliminating the risk of flashback. The large cross-section of the airflow channel eliminates restrictions on the concentration and type of VOCs in the waste gas, allows the waste gas to carry dust and droplets, and can handle a variety of waste gas conditions and has a wide range of applications.

[0024] 4. The present invention arranges a first heat storage body and a second heat storage body in the furnace. The heat storage layers of the first heat storage body and the second heat storage body maintain the stable combustion of the premixed gas of exhaust gas, air and combustion-supporting gas in the heat storage body, forming a flameless combustion mode, with uniform combustion temperature, avoiding the generation of local high temperature, and low flue gas nitrogen oxide emission concentration.

[0025] 5. The premixing chamber of the present invention adopts a funnel-shaped structure, and the secondary nozzles and air holes are evenly distributed along the center circumference of the premixing chamber. The center of the bottom of the premixing chamber is the inlet of the combustion-supporting gas, primary air and organic waste gas. The accelerated primary mixed gas is blocked by the air flow distribution orifice plate, forming a disturbance in the premixing chamber, enhancing the mixing effect, facilitating the complete combustion of the waste gas, and reducing the concentration of organic waste gas in the exhaust gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments or the prior art.

[0027] Figure 1 It is the overall structural diagram of the present invention;

[0028] Figure 2 is a structural diagram of the first burner of the present invention;

[0029] Figure 3 is a top view of the first burner of the present invention;

[0030] Among them, 1-furnace, 2-first burner, 3-second burner, 4-first heat storage body, 5-second heat storage body, 6-insulation wall, 7-combustion chamber, 8-burner body, 9-combustion gas channel, 10-primary air channel, 11-organic waste gas channel, 12-premixing chamber, 13-air flow distribution orifice, 14-air hole, 15-secondary air channel, 16-secondary air nozzle, 17-third heat storage body, 18-combustion gas nozzle, 19-primary mixed gas nozzle, 20-primary premixed gas nozzle. DETAILED DESCRIPTION

[0031] The present invention will be described more clearly and completely below by way of a preferred embodiment in conjunction with the accompanying drawings, but the present invention is not limited to the scope of the embodiment.

[0032] like Figure 1-Figure 3The figure shows a heat storage type organic waste gas combustion device disclosed in the present invention, comprising a furnace 1, a first burner 2 and a second burner 3 of the same structure are arranged at the bottom of the furnace 1, a first heat storage body 4 and a second heat storage body 5 are arranged at the outlets of the first burner 2 and the second burner 3 in the furnace 1, and an insulation wall 6 is arranged between the first heat storage body 4 and the second heat storage body 5. The insulation wall 6 separates the first heat storage body 4 and the second heat storage body 5. A combustion chamber 7 for connecting the first heat storage body 4 and the second heat storage body 5 is provided above the insulation wall in the furnace 1, and the gas flows between the first heat storage body 4 and the second heat storage body 5 through the combustion chamber 7; air inlets are provided on the first burner 2 and the second burner 3. During the heat storage combustion process, the air inlet of one of the burners is used as an exhaust channel.

[0033] During the combustion process, the gas passes through the heat storage layers of the first heat storage body 4 and the second heat storage body 5 to undergo flameless combustion twice, with good combustion uniformity, which can improve the treatment effect of organic waste gas and reduce emission concentration.

[0034] In order to avoid the blockage of the air intake channel due to the dust and droplets present in the organic waste gas, and to prevent the occurrence of backfire flash explosion, in a specific embodiment, the first burner 2 of the present invention includes a burner body 8, a combustion-supporting gas channel 9 is provided at the inlet end of the burner body 8, and a primary air channel 10 is concentrically provided outside the combustion-supporting gas channel 9; an organic waste gas channel 11 is concentrically provided outside the primary air channel, and the channel outlet located in the inner circle is lower than the channel outlet located in the outer circle. The outlet ends of the combustion-supporting gas channel 9, the primary air channel 10, and the organic waste gas channel 11 all adopt a conical structure with a gradually decreasing diameter. The combustion-supporting gas, primary air and organic waste gas converge at the outlet end of the organic waste gas channel 11 and flow to a premixing chamber 12 connected to the organic waste gas channel, and are mixed in the premixing chamber 12; the premixing chamber 12 adopts a funnel-shaped structure, and an air flow distribution orifice plate 13 connected to the furnace 1 is provided at the top of the premixing chamber 12, and an air hole 14 is provided on the air flow distribution orifice plate 13, and the mixed gas enters the furnace from the air hole.

[0035] The gas is accelerated through the conical area at the outlet of the channel, and the speed at the burner outlet is as high as 90~120m / s, which exceeds the propagation speed of the flame and will not produce backfire flash explosion. At the same time, the highly transported gas can carry out dust and droplets to avoid blockage of the channel.

[0036] During the combustion process, the flue gas after combustion will take away the heat in the furnace, and the new external air entering the furnace will absorb the energy in the furnace, resulting in the treatment temperature of the organic waste gas failing to meet the requirements, causing incomplete combustion and making the discharged waste gas fail to meet the standards; in order to reduce energy loss and maintain the temperature in the furnace stable, the present invention provides a secondary air channel 15 outside the organic waste gas channel 11 of the burner body 8, and the secondary air channel 15 surrounds the outside of the organic waste gas channel 11 and the premixing chamber 12, and a secondary air nozzle 16 connected to the secondary air channel 15 is provided on the premixing chamber 12, and the secondary air nozzle 16 is evenly distributed along the central circumference of the premixing chamber 12, and the air hole 14 corresponds to the secondary air nozzle 16; a third heat storage body 17 is provided at the air inlet end of the secondary air channel 15, and the third heat storage body 17 stores heat when the secondary air channel is used as an exhaust channel.

[0037] Heat is stored by the third heat storage body located on the outlet side to absorb the heat in the flue gas after combustion. After the heat storage is completed, the intake and exhaust directions of the combustion are changed, so that the secondary air is heated by the third heat storage body and then enters the premixing chamber for mixing, thereby reducing the heat absorbed by the premixed gas from the furnace, improving energy utilization, and maintaining the stability of the combustion temperature in the furnace to ensure the combustion treatment effect of the organic waste gas; the secondary air channel 15 can be lined with insulation material to insulate the preheated secondary high-temperature air and reduce heat loss before entering the furnace for combustion. A temperature sensor is set in the secondary air channel, and the temperature sensor is electrically connected to the control system for controlling the state switching of the first burner 2 and the second burner 3, and automatically switches according to the temperature on the exhaust side.

[0038] The present invention also provides a combustion method based on the above-mentioned thermal storage type organic waste gas combustion device, comprising the steps of:

[0039] S01. First, gas premixing is performed. Combustion gas, primary air, organic waste gas and secondary air enter the premixing chamber from the upper channel of the first burner and are fully mixed in the premixing chamber.

[0040] S02, then a combustion is carried out, and the premixed gas enters the first combustion body of the furnace through the air holes on the air flow distribution plate and burns.

[0041] S03, the flue gas generated by the combustion in the first heat storage body enters the combustion chamber from the first heat storage body under the heat conduction effect of the heat insulation wall, and then flows back from the top of the combustion chamber into the second heat storage body for secondary combustion;

[0042] S04, then performing flue gas heat storage. The flue gas after secondary combustion in the second heat storage body enters the premixing chamber of the second burner through the air holes, and flows back through the third heat storage tank of the second burner from the secondary air nozzle. The third heat storage tank of the second burner absorbs heat from the flue gas to store heat.

[0043] S05. Finally, the flue gas temperature is detected by a temperature sensor. As the heat storage process proceeds, the temperature of the third heat accumulator located on the exhaust side will increase, and the ability to absorb the heat of the flue gas will decrease, which will cause the flue gas temperature on the exhaust side to increase. When the temperature reaches the set value, the third heat accumulator of the second burner has completed heat storage, and the control system controls the switching of the combustion state. The second burner supplies gas for combustion, and the flue gas is discharged from the secondary air channel of the first burner. This cyclic switching can not only ensure the full combustion of the organic waste gas, but also use the energy of the previous exhaust to preheat the subsequent secondary air, thereby reducing energy loss.

[0044] The combustion-supporting gas of the present invention is accelerated for the first time at the combustion-supporting gas nozzle 18, enters the primary air channel 10, is mixed for the first time at the first mixer nozzle 19, and is accelerated again to enter the organic waste gas channel 11, is mixed with the organic waste gas again at the first premixed gas nozzle 20 and is accelerated for the third time, and finally enters the premixing chamber 12, is mixed again with the secondary air entering from the secondary air channel 15 to form a secondary mixed gas, and finally enters the heat accumulator of the furnace for flameless combustion after being pressure-equalized by the air flow distribution orifice plate 13. The fully mixed gas can be fully burned in the furnace, avoiding the phenomenon of local incomplete combustion.

[0045] In step S04, when the secondary air channel of the second burner is used as the exhaust channel, the combustion-supporting gas channel, the organic waste gas channel and the primary air channel of the second burner are closed, and the channel outlet pressure is greater than the secondary air channel pressure of the second burner, which can avoid the backflow of flue gas and can be discharged smoothly from the exhaust channel.

[0046] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A heat storage type organic waste gas combustion device, characterized in that: The invention comprises a furnace (1), a first burner (2) and a second burner (3) of the same structure are arranged at the bottom of the furnace (1), a first heat storage body (4) and a second heat storage body (5) are arranged at the outlets of the first burner (2) and the second burner (3) in the furnace (1), a heat insulation wall (6) is arranged between the first heat storage body (4) and the second heat storage body (5), and the heat insulation wall (6) separates the first heat storage body (4) and the second heat storage body (5), and a combustion chamber (7) for connecting the first heat storage body (4) and the second heat storage body (5) is arranged above the heat insulation wall in the furnace (1), and gas flows between the first heat storage body (4) and the second heat storage body (5) through the combustion chamber (7); air inlets are arranged on both the first burner (2) and the second burner (3), and during the heat storage combustion process, the air inlet of one of the burners serves as an exhaust passage; The first burner (2) comprises a burner body (8), an oxidizing gas channel (9) is provided at the inlet end of the burner body (8), and a primary air channel (10) is concentrically provided outside the oxidizing gas channel (9); an organic waste gas channel (11) is concentrically provided outside the primary air channel, and the channel outlet located in the inner circle is lower than the channel outlet located in the outer circle; the oxidizing gas, primary air and organic waste gas converge at the outlet end of the organic waste gas channel (11) and flow into a premixing chamber (12) connected to the organic waste gas channel, and are mixed in the premixing chamber (12); the premixing chamber (12) adopts a funnel-shaped structure, and an air flow distribution orifice plate (13) connected to the furnace (1) is provided at the top of the premixing chamber (12), and air holes (14) are provided on the air flow distribution orifice plate (13), and the mixed gas enters the furnace through the air holes; The outlet ends of the combustion-supporting gas channel (9), the primary air channel (10), and the organic waste gas channel (11) all adopt a tapered structure with a gradually decreasing diameter.

2. A thermal storage type organic waste gas combustion device according to claim 1, characterized in that: The burner body (8) is provided with a secondary air channel (15) outside the organic waste gas channel (11), the secondary air channel (15) surrounds the organic waste gas channel (11) and the outside of the premixing chamber (12), and a secondary air nozzle (16) communicating with the secondary air channel (15) is provided on the premixing chamber (12).

3. A regenerative organic waste gas combustion device according to claim 2, characterized in that: The secondary air nozzles (16) are evenly distributed along the central circumference of the premixing chamber (12), and the air holes (14) correspond to the secondary air nozzles (16); a third heat storage body (17) is provided at the air inlet end of the secondary air channel (15), and the third heat storage body (17) stores heat when the secondary air channel serves as an exhaust channel.

4. A thermal storage type organic waste gas combustion device according to claim 3, characterized in that: The secondary air passage (15) is lined with a heat-insulating material to insulate the preheated secondary high-temperature air. A temperature sensor is provided in the secondary air passage, and the temperature sensor is electrically connected to a control system for controlling the state switching of the first burner (2) and the second burner (3).

5. The combustion method of a thermal storage type organic waste gas combustion device according to claim 4, characterized in that: Including steps: S01. First, gas premixing is performed. Combustion gas, primary air, organic waste gas and secondary air enter the premixing chamber from the upper channel of the first burner and are fully mixed in the premixing chamber. S02, then a combustion is carried out, and the premixed gas enters the first combustion body of the furnace through the air holes on the air flow distribution plate and burns. S03, the flue gas generated by the combustion in the first heat storage body enters the combustion chamber from the first heat storage body under the heat conduction effect of the heat insulation wall, and then flows back from the top of the combustion chamber into the second heat storage body for secondary combustion; S04, then performing flue gas heat storage. The flue gas after secondary combustion in the second heat storage body enters the premixing chamber of the second burner through the air holes, and flows back through the third heat storage tank of the second burner from the secondary air nozzle. The third heat storage tank of the second burner absorbs heat from the flue gas to store heat. S05. Finally, the temperature sensor detects the flue gas temperature. When the temperature reaches the set value, the third heat accumulator of the second burner completes heat storage. The control system controls the combustion state switching, and the second burner supplies gas for combustion, and the flue gas is discharged from the secondary air channel of the first burner.

6. The combustion method of a thermal storage type organic waste gas combustion device according to claim 5, characterized in that: In step S01, the combustion-supporting gas and primary air of the first burner are accelerated through their respective channel outlets, and then gathered with the organic waste gas at the outlet of the organic waste gas channel to form a primary premixed gas. After being accelerated again, they enter the premixing chamber. The secondary air enters the premixing chamber from the secondary air channel of the first heat exchanger, and is disturbed and mixed by the primary premixed gas to form a secondary premixed gas.

7. The combustion method of a thermal storage type organic waste gas combustion device according to claim 5, characterized in that: In step S04, when the secondary air channel of the second burner is used as the exhaust channel, the combustion-supporting gas channel, the organic waste gas channel and the primary air channel of the second burner are closed, and the channel outlet pressure is greater than the secondary air channel pressure of the second burner.

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