CN115875682A - Combustion apparatus and exhaust gas treatment method - Google Patents

Abstract

The application discloses a combustion apparatus and a method of treating exhaust gas. The combustion device comprises a first air supply mechanism, a second air supply mechanism, a first mixing mechanism, a second mixing mechanism, a combustion chamber, a combustion mechanism and a third air supply mechanism; the gas outlet of the first gas supply mechanism is communicated with the first mixing mechanism and is used for supplying first gas to the first mixing mechanism; and the gas outlet of the second gas supply mechanism is communicated with the combustion chamber and is used for supplying second gas to the combustion chamber. The utility model provides a burning mechanism has solved low concentration, little flow, the undulant VOC exhaust-gas treatment problem that just intermittent type nature discharged of component through handling the waste gas of different calorific values respectively. The combustion device further ensures that the waste gas can be safely and stably combusted under the condition of low heat value and small flow through intensive mixing, surface premixed combustion and auxiliary combustion supporting modes.

Description

Combustion device and waste gas treatment method

technical field

The present application relates to the field of petrochemical technology, in particular to a combustion device and a waste gas treatment method.

Background technique

The treatment technology of industrial VOC is mainly divided into recovery technology and decomposition technology. Among them, the decomposition technology refers to the treatment of VOC through thermal oxidation or thermal decomposition, such as direct combustion (TO method), catalytic combustion (CO method) or regenerative combustion (RTO method), but these technologies also have obvious differences. shortcoming. TO furnaces are generally suitable for high-concentration VOC waste gas treatment. When low-concentration VOC treatment is required, more combustion-supporting fuels are required, energy consumption is large, waste heat recovery is required, and the system is complex. Due to the slow start-up time, it generally takes 1h-2h, which is suitable for continuous emission of VOC treatment, not suitable for intermittent emission emission. Another convenience is that because TO furnaces are prone to high temperature locally, it is easy to cause high _NOx emissions. The RTO furnace is limited by the heating rate of the ceramic regenerator, and the start-up time of the equipment is relatively slow. Generally, it takes 2h-4h. It is only suitable for the treatment of VOC waste gas that is continuously discharged, and is not suitable for intermittent treatment. In addition, the RTO furnace has strict requirements on the VOC intake concentration, and the concentration must be lower than 25% of its lower explosion limit, which is not suitable for VOC exhaust gas with large component fluctuations. Because the CO furnace needs to preheat the exhaust gas, it generally adopts electric heating or flue gas heating, and the equipment start-up time is also relatively slow, generally taking 1h-2h. It is only suitable for continuous emission of VOC exhaust gas treatment, not suitable for intermittent treatment. In addition, like the RTO furnace, the CO furnace has strict requirements on the VOC intake concentration and composition, the concentration must be lower than 25% of its lower explosion limit, and the exhaust gas must not contain components that poison the catalyst. Long-term operation will generate solid waste pollutants.

The VOC exhaust gas discharged from tank farms in the petrochemical industry often has the following characteristics: low concentration (generally no more than 300g/m ³ ), small flow rate (single exhaust gas generally does not exceed 2000Nm ³ /h), intermittent emission, and large fluctuations in components Features. This kind of VOC exhaust gas adopts traditional incineration treatment technology, such as CO furnace, TO furnace, RTO furnace, etc., which will have obvious shortcomings. In the treatment of waste gas in this field, condensation adsorption or oil recovery adsorption is mainly used in China. Although this method is safe and feasible, it has high equipment energy consumption, high operating costs, and the treatment rate of NMHC (non-methane total hydrocarbons) Not high-level disadvantages, but also gradually unable to meet environmental protection standards.

The above combustion methods have obvious problems in dealing with VOC waste gas with intermittent emissions, large component fluctuations, low concentration and low flow rate. Even if the VOC waste gas with low concentration and low flow rate is treated, it will cause huge energy consumption and equipment maintenance costs, and there are problems such as complex equipment and extremely low economic returns.

Contents of the invention

The purpose of this application is to provide a combustion device and a waste gas treatment method. The combustion device of the present application solves the above-mentioned technical problems by improving the structure and treating waste gases with different calorific values separately.

An embodiment of the present application provides a combustion device, including a first air supply mechanism, a second air supply mechanism, a first mixing mechanism, a second mixing mechanism, a combustion chamber, a combustion mechanism and a third air supply mechanism;

The gas outlet of the first gas delivery mechanism communicates with the first mixing mechanism for sending the first gas into the first mixing mechanism;

The gas outlet of the second air supply mechanism communicates with the combustion chamber, and is used to send the second gas into the combustion chamber;

The air outlet of the first mixing mechanism communicates with the air inlet of the second mixing mechanism for sending the mixed gas into the second mixing mechanism;

The air outlet of the second mixing mechanism communicates with the air inlet of the combustion mechanism, and is used to send the mixed gas into the combustion mechanism;

The combustion mechanism is located inside the combustion chamber for providing a combustion surface;

The air outlet of the third air delivery mechanism communicates with the first mixing mechanism for sending fuel gas into the first mixing mechanism.

In some embodiments, the first air delivery mechanism includes a first pipeline, a first injection mechanism and a second injection mechanism;

The first injection mechanism is arranged at the gas outlet end of the first pipeline, and the diameter of the first injection mechanism decreases gradually along the axial direction;

The second injection mechanism is arranged around the first pipeline, and is used to change the first gas flowing along the axial direction into a radial flow and send it into the first mixing mechanism.

In some embodiments, the first spraying mechanism is provided with first spray holes, and the first spray holes are arranged in a row;

Along the radial direction, the second injection mechanism is provided with a second injection hole.

In some embodiments, along the radial direction, the distance between the second injection holes decreases gradually.

In some embodiments, along the radial direction, the diameter of the second nozzle hole gradually increases.

In some embodiments, the second air supply mechanism includes an annular second pipeline and a third injection mechanism communicated with the second pipeline; the third injection mechanism includes a The air jet element and the first spray head arranged at the air outlet of the air jet element.

In some embodiments, the air injection port of the first spray head is provided with an air injection end surface, and the air injection end surface is provided with a third injection hole.

In some embodiments, the combustion mechanism has a circular frustum structure, and the diameter of the combustion mechanism gradually decreases along the direction of air flow.

In some embodiments, the included angle between the jet end surface and the surface of the combustion mechanism is less than 90°.

In some embodiments, the first mixing mechanism includes a first mixing chamber and a swirl mechanism;

The first mixing chamber is sleeved on the outer periphery of the first pipeline;

The swirl mechanism is arranged at the gas outlet end of the first pipeline.

In some embodiments, the third air supply mechanism includes a third pipeline and a fourth injection mechanism arranged at the air outlet of the third pipeline;

the third pipeline extending along the axial direction inside the first pipeline;

Along the axial direction, the first pipeline has a first end and a second end respectively, and the fourth injection mechanism is arranged at the second end of the first pipeline.

In some embodiments, the swirl mechanism includes several swirl blades extending along the circumferential direction.

In some embodiments, the swirl angle of the swirl blades is 30°-45°.

In some embodiments, the combustion device includes a fourth air delivery mechanism, and the fourth air delivery mechanism is used for sending combustion oxidizer into the combustion chamber.

In some embodiments, the combustion device includes an ignition mechanism for igniting the exhaust gas sent into the combustion chamber.

In some embodiments, the combustion device includes a detection mechanism for detecting the state of flame combustion.

Correspondingly, the embodiment of the present application also provides an exhaust gas treatment method, the exhaust gas treatment method utilizes the above-mentioned combustion device for exhaust gas treatment, including the following steps:

(a) The first gas with a high calorific value is sent into the combustion device for combustion through the first air delivery mechanism;

(b) The second gas with low calorific value is sent to the combustion device for combustion through the second air delivery mechanism.

The beneficial effects of the present application are: the combustion device provided by the application solves the problem of VOC waste gas treatment with low concentration, small flow rate, large component fluctuation and intermittent emission by setting different air supply mechanisms; the combustion device provided by the application further passes Enhanced mixing, surface premixed combustion and auxiliary combustion methods ensure safe and stable combustion of exhaust gas at low calorific value and small flow rate; the combustion device of this application improves the treatment rate of NMHC, and the emission of NOx, CO and other pollutants can also meet National and local environmental protection requirements.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 is the structural representation of embodiment 1 of the present application;

Fig. 2 is the sectional view of embodiment 1 of the present application;

Fig. 3 is a schematic diagram of an enlarged structure of part A in Fig. 2;

Fig. 4 is a top view of the first air supply mechanism in Embodiment 1 of the present application;

Fig. 5 is a schematic structural view of the first air delivery mechanism in Embodiment 1 of the present application;

6 is a schematic structural view of the second air supply mechanism in Embodiment 1 of the present application;

Fig. 7 is a schematic diagram showing the enlarged structure of part B of Fig. 6;

Fig. 8 is a top view of the swirl mechanism and the third air supply mechanism in Embodiment 1 of the present application;

Fig. 9 is a schematic structural view of the swirl mechanism and the third air supply mechanism in Embodiment 1 of the present application;

Among them, 1-the first air supply mechanism, 110-the first end, 120-the second end, 11-the first pipeline, 111-the first air inlet, 12-the first injection mechanism, 121-the first nozzle hole, 13-second injection mechanism, 131-second nozzle hole, 2-second air delivery mechanism, 21-second pipeline, 22-third injection mechanism, 221-air injection element, 222-first nozzle, 223-air injection end surface , 224-the third injection hole, 3-the first mixing mechanism, 31-the mixing chamber, 32-the swirl mechanism, 321-the swirl vane, 4-the second mixing mechanism, 5-the combustion chamber, 51-the flue gas outlet, 6-combustion mechanism, 7-third air supply mechanism, 71-third pipeline, 711-second air inlet, 72-fourth injection mechanism, 721-second nozzle, 8-fourth air supply mechanism, 9-ignition Mechanism, 10—detection mechanism, 101—first flame detection device, 102—second flame detection device, 103—electric thermocouple.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the application with reference to the drawings in the embodiments of the application. Apparently, the described embodiments are only some of the embodiments of the application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application. In addition, in the description of the present application, the term "including" means "including but not limited to". The terms first, second, third, etc. are used for designation only and do not impose numerical requirements or establish an order. Various embodiments of the application may be presented in a range format; it should be understood that the description in a range format is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of the application.

In order to better solve the problem of VOC waste gas treatment with low concentration, small flow rate, large component fluctuations and intermittent emissions, the embodiment of this application proposes a combustion device, as shown in Figure 1, Figure 2 and Figure 3, the The combustion device includes: a first air supply mechanism 1 , a second air supply mechanism 2 , a first mixing mechanism 3 , a second mixing mechanism 4 , a combustion chamber 5 , a combustion mechanism 6 and a third air supply mechanism 7 . In FIG. 2 , the direction in which the X axis extends is the axial direction, which is also the direction from the rear end to the front end described in this embodiment, and the direction in which the Y axis extends is the radial direction, which is also the span direction described in this embodiment.

In this embodiment, the air outlet of the first air supply mechanism 1 communicates with the first mixing mechanism 3 for sending the first gas into the first mixing mechanism 3, and the air outlet of the third air supply mechanism 7 communicates with the first mixing mechanism 3 communicated, and is used to send fuel gas into the first mixing mechanism 3 . The gas outlet of the first mixing mechanism 3 is communicated with the air inlet of the second mixing mechanism 4, and the gas mixed through the first mixing mechanism 3 is sent into the second mixing mechanism 4; the gas outlet of the second mixing mechanism 4 is connected with the combustion mechanism The air inlet of 6 is connected, and is used to send the mixed gas into the combustion mechanism 6; the combustion mechanism 6 is located inside the combustion chamber 5, and is used to provide a combustion surface.

In this embodiment, the gas outlet of the second air supply mechanism 2 communicates with the combustion chamber 5 for sending the second gas into the combustion chamber 5 , and the second gas sent into the combustion chamber 5 burns on the surface of the combustion mechanism 6 .

The first gas and the second gas in this embodiment may be the same or different. In a specific embodiment, the first gas is different from the second gas. As an optional implementation, the concentration of organic matter in the first gas ranges from 50 g/m ³ to 350 g/m ³ , and the organic matter in the second gas The concentration range is below 50 mg/m ³ .

In this application, different exhaust gases (according to the concentration, flow rate, composition and other conditions of the multiple exhaust gases, the exhaust gases are divided into two main roads: the main exhaust gas is the first gas and the branch exhaust gas is the second gas) are pre-mixed and passed through the first respectively. The air supply mechanism 1 and the second air supply mechanism 2 are sent into the combustion device. Different exhaust gases are fed into the combustion chamber 5 through different paths, which avoids large fluctuations in the calorific value of the exhaust gases due to different sources of exhaust gases, which cannot achieve continuous combustion, or the burner adjustment range is too large due to large fluctuations in gas components, and the adjustment performance is poor. The exhaust gas sent through the first air supply mechanism 1 is mixed intensively through the first mixing mechanism 3 and the second mixing mechanism 4 to ensure that the exhaust gas can be burned safely and stably even in the case of low calorific value and small flow rate, and the treatment rate of NMHC, NO _x , The discharge of pollutants such as CO can also meet environmental protection requirements.

In a specific embodiment, the combustion aid is sent into the first mixing mechanism 3 through the fourth air supply mechanism 8, that is, the first gas supply mechanism 1 is used to send the first gas into the first mixing mechanism 3, and the third gas supply mechanism 7 Send the fuel gas into the first mixing mechanism 3, and the fourth air supply mechanism 8 sends the combustion aid into the first mixing mechanism 3. After the first mixing mechanism 3 completes the mixing of the first gas, fuel gas and combustion aid, the mixed gas The gas is sent to the second mixing mechanism 4, and the gas mixed in the second mixing mechanism 4 is sent to the combustion mechanism 6 located in the combustion chamber 5 for combustion.

In a specific embodiment, the fourth air supply mechanism 8 is an air supply duct opening to the first mixing mechanism 3 , and the air supply duct communicates with a blower for sending air into the first mixing mechanism 3 as a combustion aid.

In a specific embodiment, the combustion device further includes an ignition mechanism 9 for igniting the exhaust gas sent into the combustion chamber 5 .

In a specific embodiment, the combustion chamber 5 is composed of a combustion cylinder. In a specific application, the height of the combustion cylinder is not less than 12 meters, and the height of the entire combustion device is not less than 15 meters.

In a specific embodiment, the combustion device further includes a detection mechanism 10, and the detection mechanism 10 includes a first flame detection device 101 disposed in the combustion chamber 5 and a second flame detection device 102 disposed inside the first mixing mechanism 3 , can judge at any time as the ignition gun of the ignition mechanism 9 and as the flame state of the burner of the combustion mechanism 6. Further, along the axial direction X, a number of thermocouples 103 are arranged at different positions of the combustion chamber 5 to detect the flue gas temperature in the combustion cylinder. or lower, the temperature detection signal of the thermocouple will be fed back to the control valve group of the fan and fuel gas to adjust the fuel gas volume and combustion aid (air) flow accordingly to maintain the temperature of the combustion cylinder within the design range.

As shown in FIG. 4 and FIG. 5 , the first air delivery mechanism 1 of the present application includes a first pipeline 11 , a first injection mechanism 12 and a second injection mechanism 13 . The first air inlet 111 of the first pipeline 11 is the inlet of the first gas. The first pipeline 11 extends along the axial direction X and is located inside the first mixing mechanism 3 for sending the first gas into the first Mixing in the mixing mechanism 3. The first spraying mechanism 12 is arranged at the gas outlet end of the first pipeline 11 , and the first spraying mechanism 12 is used to send the first gas out of the first pipeline 11 and realize uniform distribution of the first gas in the first mixing mechanism 3 . In order to achieve a better mixing effect, the first injection mechanism 12 is a hollow conical structure, the diameter of the first injection mechanism 12 gradually decreases along the axial direction X, and the conical surface formed by the first injection mechanism 12 is provided with the first nozzle hole 121 . In this application, through the design of the conical surface structure, the flow velocity of the first gas sent out from the first nozzle hole 121 is increased, and the mixing effect thereof is increased. The first nozzle holes 121 can be arranged in different ways. In order to realize the uniform mixing of the gas, the first nozzle holes 121 are arranged in rows on the conical surface formed by the first injection mechanism 12. Between the first nozzle holes 121 The distances are the same, and the diameters of the first spray holes 121 are the same, so as to ensure uniform distribution of the airflow space. In a specific embodiment, the diameter of the first nozzle hole 121 is 2mm˜4mm.

In this embodiment, a second injection mechanism 13 is provided on the side wall of the gas outlet end of the first pipeline 11, and the second injection mechanism 13 is arranged around the first pipeline 11. In a specific embodiment, the second injection mechanism 13 is the same as the first pipeline An injection pipe connected by a pipeline 11, the outlet end of the injection pipe is closed, and the second injection mechanism 13 is used to change the first gas flowing along the axial direction X into a radial Y flow, and at the same time pass through the second injection mechanism 13 The upper second spray hole 131 is sent into the first mixing mechanism 3 . The second nozzle holes 131 are distributed along the radial direction Y on the second injection mechanism 13, and along the radial direction Y, the distance between the second nozzle holes 131 decreases gradually, and the distance between adjacent second nozzle holes 131 decreases. The ratio of the ratio can be reduced according to the geometric sequence, and the aperture of the second nozzle hole 131 gradually increases, and the ratio of the diameter of the second nozzle hole 131 can be increased according to the geometric sequence or the arithmetic sequence. In specific applications, The aperture of the second nozzle hole 131 can be selected within the range of 2 mm to 4 mm; through the design of the second nozzle hole 131 with reduced pitch and gradually increased aperture, the exhaust gas can enter the first mixing mechanism more uniformly through the second nozzle hole 131 3. In a specific embodiment, each second injection mechanism 13 is provided with two rows of second nozzle holes 131 , and the second nozzle holes 131 are located on the side of the second injection mechanism 13 away from the first air inlet 111 .

Part of the first gas is directly sent into the first mixing mechanism 3 through the first injection mechanism 12, partly is sent into the first mixing mechanism 3 through the second injection mechanism 13, and the gas sent through the first injection mechanism 12 and the second injection mechanism 13 Due to the different directions of the gas sent out, the first gas can be uniformly distributed in space; the gas sent out through the second injection mechanism 13 is more uniformly distributed in the plane area perpendicular to the axial direction in the channel of the first mixing mechanism 3 . The oxidizer fed in is mixed.

As shown in FIG. 6 and FIG. 7 , the second air supply mechanism 2 in this embodiment includes an annular second pipeline 21 and a third injection mechanism 22 communicating with the second pipeline 21 . The second air supply mechanism 2 is arranged at the inlet end of the combustion chamber 5, and directly sends the second gas into the combustion chamber 5, and the second gas sent in is ignited by the ignition mechanism 9, and burns on the surface of the combustion mechanism 6.

The second pipeline 21 of the second air supply mechanism 2 is an annular pipeline, which is arranged around the inlet end of the combustion chamber 5. The second pipeline 21 is connected with several third injection mechanisms 22, and the third injection mechanism 22 is along the axial direction X. The direction extends, and the second gas is divided into several branches and sent into the combustion chamber 5. In a specific embodiment, the number of the third injection mechanism 22 is selected as an even number, and they are arranged symmetrically along the circumferential direction.

The third injection mechanism 22 includes an air injection element 221 communicated with the second pipeline 21 and a first shower head 222 arranged at the air outlet of the air injection element 221. There are third injection holes 224 , and the third injection holes 224 may be evenly spaced on the air injection end surface 223 . In this embodiment, the air spray element 221 may be a nozzle communicated with the second pipeline 21 , and the first nozzle 222 is arranged at the gas outlet end of the nozzle. In a specific embodiment, the diameter of the third injection hole 224 is 2mm˜4mm.

The first mixing mechanism 3 includes a mixing chamber 31 and a swirl mechanism 32 . The mixing chamber 31 is a cavity disposed on the periphery of the first pipeline 11 for providing a gas mixing chamber. As shown in FIG. 8 , the arrangement of the swirl mechanism 32 in this embodiment further improves the gas mixing effect. Specifically, the first pipeline 11 has a first end 110 and a second end 120 along the axial direction X. The second end 120 of the first pipeline 11 is provided with a swirl mechanism 32, and the swirl mechanism 32 includes a plurality of swirl vanes 321, and the plane where the plurality of swirl vanes 321 is located is in line with the radial section (Y-Z axis plane) of the combustion device. ) parallel, the swirl blade 321 may be a helical blade. In some specific embodiments, the swirl angle of the swirl blades 321 is 30°-45°, which further improves the mixing effect of the airflow passing through the swirl blades. In a specific application example, the diameter of the swirl blade 321 is 2/3 times the diameter of the outer cylinder of the first mixing mechanism 3 .

In this implementation, through the setting of the first spraying mechanism 12 in a conical structure, several second spraying mechanisms 13 surrounding the first pipeline 11, and the swirl mechanism 32 arranged at the front end of the first pipeline 11, increasing The swirling strength of the first gas and the supporting gas is improved, so that the first gas, the supporting gas and the fuel gas sent from the second nozzle 721 are fully mixed.

As shown in Figure 9, in this embodiment, the fuel gas is sent in through the third air supply mechanism 7, the third air supply mechanism 7 includes a third pipeline 71 and a fourth injection mechanism 72 arranged at the gas outlet of the third pipeline 71, The fuel gas is sent into the third pipeline 71 through the second air inlet 711 of the third pipeline 71 . Since the fuel gas fed in is less, in order to fully mix it with the first gas and the combustion oxidant, in this embodiment, the third pipeline 71 is arranged inside the first pipeline 11, and the third pipeline 71 is along the The axial direction X extends inside the first pipeline 11. As an optional embodiment, the third pipeline 71 and the first pipeline 11 are arranged concentrically in the direction of the axial central axis _O1 of the combustion device. The fourth injection mechanism 72 is a delivery mechanism for fuel gas. The fourth injection mechanism 72 is arranged at the second end 120 of the first pipeline 11, and the fourth injection mechanism 72 is located at the front end of the swirl mechanism 32. The fourth injection mechanism 72 includes The second nozzle 721 is used for sending out the fuel gas. Several nozzle holes are arranged on the second nozzle 721 . In a specific application embodiment, the diameter of the nozzle hole of the fuel gas is 1mm-1.5mm.

In this embodiment, the outlet of the third air supply mechanism 7 is located at the front end of the first injection mechanism 12, the second injection mechanism 13 and the swirl mechanism 32, which ensures that the fuel gas with a small flow rate sent in through the second spray nozzle 721 is pre-swirled. The large flow of gas-supporting gas of the flow mechanism 32 drives the rotation to ensure the mixing effect of the two. At the same time, the third gas supply mechanism 7 arranged in this way does not affect the gas mixing effect, and the gas mixing effect is increased through the improvement of the three structures.

In this embodiment, the second mixing mechanism 4 is a Venturi structure arranged at the gas outlet of the first mixing mechanism 3, and the position of the Venturi throat and the minimum flow rate of the gas distributor under the metal fiber mesh of the combustion mechanism 6 are designed to be greater than the corresponding The flame combustion speed of the premixed gas can further avoid the occurrence of flashback.

The gas outlet of the second mixing mechanism 4 communicates with the combustion chamber 5 , the combustion chamber 5 has a flue gas outlet 51 , and the combustion chamber 5 is provided with a combustion mechanism 6 at its entrance.

In this embodiment, the combustion mechanism 6 is a bottom firing arrangement. In order to avoid the influence of the airflow out from the rear end of the combustion mechanism 6 on the airflow outflow from the front end of the combustion mechanism 6, the combustion mechanism 6 has a hollow circular truncated structure as a whole, and its diameter gradually decreases along the direction of axial X extension, further reducing the flames between the upper and lower sides. put one's oar in.

As shown in Figure 7, in order to avoid that the exhaust gas with low calorific value sent by the second air supply mechanism 2 cannot be stably burned on the surface of the combustion mechanism 6, in this embodiment, the angle between the air injection end surface 223 and the surface of the combustion mechanism 6 is less than 90°. angle, so that the low calorific value exhaust gas is sprayed from multiple nozzle holes of the third nozzle hole 224, and the axial direction uniformly contacts the flame surface of the surface burner or reaches the vicinity of the flame surface, ensuring sufficient combustion of the low calorific value gas but not easy to blow out the flame.

In this embodiment, the combustion mechanism 6 adopts a surface burner, and the main exhaust gas, fuel gas and combustion-supporting agent air reach the metal fiber surface of the surface burner after being uniformly mixed by the first mixing mechanism 3 and the second mixing mechanism 4 At this time, the ignition gun next to the surface burner is used to ignite to realize the combustion of the main fire of the burner. Because there are millions of microporous structures on the surface of the metal fiber, the main fire of the burner is stable on the surface of the metal fiber mesh and is not easy to flash back.

In this embodiment, in order to further ensure the stable combustion of the flame when the exhaust gas fluctuates intermittently, the ignition mechanism 9 (the ignition gun is selected in a specific application) is designed to have the function of a permanent light. When the concentration is too low to continue burning, the ignition mechanism 9 is used to maintain the stable combustion of the flame.

In a specific application, the exhaust gas treatment capacity of the combustion device ranges from 300Nm ³ /h to 3000Nm ³ /h, the maximum flow rate of fuel gas sent by the third air supply mechanism 7 is 30Nm ³ /h, and the concentration range of organic matter in the main exhaust gas is 50g/m ³ ~ 350g/m ³ , if the exhaust gas with an organic matter concentration of 100g/m ³ ~ 300g/m ³ is selected; the organic matter concentration range in the branch exhaust gas is below 50mg/m ³ , and the air velocity range sent by the fourth air supply mechanism 8 is 10m /s～15m/s, the maximum flow velocity range of the nozzle hole of the first injection mechanism 12 and the second injection mechanism 13 is 120～150m/s, and the maximum flow velocity of the nozzle hole of the fourth injection mechanism 72 is 150m/s～200m/s. The minimum flow velocity at the Venturi throat of the second mixing mechanism 4 is not less than 10m/s.

The flue gas temperature in the combustion chamber 5 is controlled at 1000-1200°C, the oxygen concentration at the outlet of the combustion chamber 5 is controlled at about 10%, the residence time of the flue gas is not less than 1s, and the temperature of the outer wall of the combustion chamber is not lower than 90°C.

The combustion device of the present application is suitable for the treatment of VOC waste gas with small flow rate, low concentration and large fluctuations, and intermittent emission in chemical tank farms. The combustion device uses surface premixed combustion and auxiliary combustion methods to ensure that the exhaust gas can be burned safely and stably under the condition of low calorific value and small flow rate, and the treatment rate of NMHC, NOx, CO and other pollutant emissions can also meet the national and local environmental protection requirements Require.

The working principle of the combustion equipment of the present application is:

According to the concentration, flow, composition and other conditions of multiple streams of waste gas, it is divided into two roads: main road waste gas (first gas) and branch road waste gas (second gas). Each exhaust gas is composed of several strands of exhaust gas, which are pre-mixed and then enter the combustion tube for combustion. The exhaust gas from the main road is mixed with the fuel gas and oxidizer air first through the pipeline layout and nozzle structure, and then mixed again through the swirl vane and Venturi, which fully ensures that the fuel gas, exhaust gas and air are fully mixed when they reach the burner. After the branch exhaust gas is evenly distributed through the ring formed by the second pipeline 21, it is sprayed into the combustion cylinder through a plurality of third injection mechanisms 22 near the burner at the bottom of the combustion cylinder and burns in contact with the high-temperature flue gas.

The application uses the combustion device to carry out the waste gas treatment method as follows:

(a) The first pipeline 11 is sent into the main road exhaust gas, the third pipeline 71 is sent into the fuel gas, and the combustion aid sent by the fourth air supply mechanism 8, the main road exhaust gas and the fuel gas are respectively sent from the first air inlet 111, After the second air inlet 711 enters, the exhaust gas from the main road is sent out by the first injection mechanism 12 and the second injection mechanism 13 arranged on the first pipeline 11, and then mixed with the air sent in by the fourth air supply mechanism 8, and passed through After the swirl blades 321 are preliminarily mixed; the fuel gas is injected through the fourth injection mechanism 72 at the front end of the swirl blades 321 and mixed with exhaust gas and air to form the final fuel premixed gas.

(b) The fuel premixed gas enters the Venturi mixing chamber of the second mixing mechanism 4 and is further mixed.

(c) The mixed fuel premixed gas enters the combustion mechanism 6, is ignited by the ignition mechanism 9, and finally forms a stable flame on the metal fiber surface of the combustion mechanism 6, and the high-temperature flue gas generated goes up through the combustion tube to the flue gas outlet 51 discharge; the first flame detection device 101 and the second flame detection device 102 respectively monitor the flame situation of the entire combustion process; when the ignition mechanism 9 ignites the burner, it acts as an ever-burning lamp and keeps the burning state.

(d) The second air supply mechanism 2 sends the branch exhaust gas into the combustion chamber 5. After passing through the second pipeline 21, the branch exhaust gas passes through the third injection mechanism 22 and evenly distributes it to each air injection element 221, and directly sprays it through the first nozzle 222. into the combustion chamber for combustion.

(e) The thermal couple 103 arranged in the height direction of the combustion cylinder can provide real-time feedback of the flue gas temperature. When the temperature deviates from the design range, the intake air volume of the fuel gas sent in by the second air inlet 711 and the air intake by the fourth air supply mechanism 8 are adjusted. Air intake volume to regulate temperature.

(f) When the VOC exhaust gas pressure in the main road does not reach the set minimum value, the third pipeline 71 feeding fuel gas is cut off at this time, the fan is adjusted to the minimum opening, and the flame of the ignition mechanism 9 remains stable.

(g) When the VOC exhaust gas pressure in the main road reaches the set minimum value, the combustion mechanism 6 starts, the air volume changes accordingly with the VOC exhaust gas flow in the main road, and the fuel gas volume is adjusted according to the temperature feedback of the thermocouple. As long as the ignition mechanism 9 is put into use, The branch VOC exhaust gas can be passed into the combustion chamber at any time.

In the foregoing embodiments, the descriptions of each embodiment have their own emphases, and for parts not described in detail in a certain embodiment, reference may be made to relevant descriptions of other embodiments.

The above is a detailed introduction to a combustion device and a waste gas treatment method provided by the embodiments of the present application. In this paper, specific examples are used to illustrate the principles and implementation methods of the present application. The descriptions of the above embodiments are only used to help understand the present application. The method of application and its core idea; at the same time, for those skilled in the art, according to the idea of this application, there will be changes in the specific implementation and application scope. In summary, the content of this specification should not be understood as Limitations on this Application.

Claims (13)

1. A combustion device, characterized in that it comprises a first air supply mechanism (1), a second air supply mechanism (2), a first mixing mechanism (3), a second mixing mechanism (4), a combustion chamber (5), Combustion mechanism (6) and the third air delivery mechanism (7); The air outlet of the first air supply mechanism (1) communicates with the first mixing mechanism (3), and is used to send the first gas into the first mixing mechanism (3); The air outlet of the second air supply mechanism (2) communicates with the combustion chamber (5), and is used to send the second gas into the combustion chamber (5); The air outlet of the first mixing mechanism (3) communicates with the air inlet of the second mixing mechanism (4), for sending the mixed gas into the second mixing mechanism (4); The air outlet of the second mixing mechanism (4) communicates with the air inlet of the combustion mechanism (6), for sending the mixed gas into the combustion mechanism (6); The combustion mechanism (6) is located inside the combustion chamber (5) for providing a combustion surface; The air outlet of the third air delivery mechanism (7) communicates with the first mixing mechanism (3) for sending fuel gas into the first mixing mechanism (3). 2. The combustion device according to claim 1, characterized in that, the first air supply mechanism (1) comprises a first pipeline (11), a first injection mechanism (12) and a second injection mechanism (13); The first injection mechanism (12) is arranged at the gas outlet end of the first pipeline (11), and along the axial (X) direction, the diameter of the first injection mechanism (12) gradually decreases; The second injection mechanism (13) is arranged around the first pipeline (11), and is used to change the first gas flowing along the axial direction (X) into a radial (Y) flow and send it into the Describe the first mixing mechanism (3). 3. The combustion device according to claim 2, characterized in that, the first injection mechanism (12) is provided with first injection holes (121), and the first injection holes (121) are arranged in a row ; Along the radial direction (Y), the second injection mechanism (13) is provided with a second injection hole (131). 4. The combustion device according to claim 3, characterized in that, along the radial direction (Y), the distance between the second injection holes (131) gradually decreases; and/or, Along the radial direction (Y), the diameter of the second spray hole (131) gradually increases. 5. The combustion device according to claim 2, characterized in that, the second air supply mechanism (2) comprises an annular second pipeline (21) and a third pipe connected to the second pipeline (21). Injection mechanism (22); the third injection mechanism (22) includes an air injection element (221) communicated with the second pipeline (21) and a first spray head arranged at the air outlet of the air injection element (221) (222). 6. The combustion device according to claim 5, characterized in that, the gas injection port of the first nozzle (222) is provided with a gas injection end surface (223), and the gas injection end surface (223) is provided with a third injection hole ( 224). 7. The combustion device according to claim 6, characterized in that, the combustion mechanism (6) has a circular truncated structure, and the diameter of the combustion mechanism (6) gradually decreases along the air flow direction. 8. The combustion device according to claim 7, characterized in that, the included angle between the gas injection end surface (223) and the surface of the combustion mechanism (6) is less than 90°. 9. The combustion device according to claim 7, characterized in that, the first mixing mechanism (3) comprises a first mixing chamber (31) and a swirl mechanism (32); The first mixing chamber (31) is sleeved on the outer periphery of the first pipeline (11); The swirl mechanism (32) is arranged at the gas outlet end of the first pipeline (11). 10. The combustion device according to claim 5, characterized in that, the third air supply mechanism (7) comprises a third pipeline (71) and a fourth gas outlet arranged at the gas outlet of the third pipeline (71). Injection mechanism (72); The third pipeline (71) extends along the axial direction (X) inside the first pipeline (11); Along the axial direction (X), the first pipeline (11) has a first end (110) and a second end (120), respectively, and the fourth injection mechanism (72) is arranged on the first The second end (120) of the pipeline (11). 11. The combustion device according to claim 9, characterized in that, the swirl mechanism (32) comprises several swirl vanes (321) extending along the circumferential direction; and/or, The swirl angle of the swirl vane (321) is 30°-45°. 12. The combustion device according to claim 1, characterized in that it comprises a fourth air supply mechanism (8), and the fourth air supply mechanism (8) is used to send a combustion aid into the combustion chamber (5); and / or, An ignition mechanism (9) is included, the ignition mechanism (9) is used to ignite the exhaust gas sent into the combustion chamber (5); and/or, A detection mechanism (10) is included, and the detection mechanism (10) is used for detecting the flame combustion state. 13. A method for treating exhaust gas using the combustion device described in any one of claims 1 to 12, characterized in that it comprises the following steps: (a) the first gas is sent into the combustion device through the first air delivery mechanism (1) for combustion; (b) The second gas is sent to the combustion device for combustion through the second air delivery mechanism (2).

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