Secondary combustion chamber

Abstract

The utility model discloses a secondary combustion chamber, and relates to the technical field of household garbage gasification incineration, the secondary combustion chamber comprises a combustion chamber, the combustion chamber is provided with a smoke inlet and a smoke outlet, the combustion chamber comprises a plurality of combustion cavities which are arranged between the smoke inlet and the smoke outlet and are communicated in sequence, the smoke inlet and the smoke outlet are communicated with the combustion cavities, and the smoke inlet and the smoke outlet are communicated with the combustion cavities. The smoke inlet is communicated with the smoke outlet, the smoke outlet is communicated with the air inducing device, a heat accumulator is arranged in each combustion cavity, combustors are arranged in the two combustion cavities close to the smoke inlet, and a denitration device is arranged in the combustion cavity close to the smoke outlet; the heat accumulators are arranged in the combustion cavities, so that the temperature in the combustion cavities is kept stable, the temperature in the combustion cavities is prevented from being too low, gas in the combustion cavities can be fully combusted, and the combustion efficiency of the combustion cavities is improved; and the combustors are arranged in the two combustion cavities close to the smoke inlet, so that the temperature in the combustion cavities is increased.

Description

Technical Field

[0001] This utility model relates to the field of biochemical waste gasification and incineration technology, and in particular to a secondary combustion chamber. Background Technology

[0002] Waste incinerators are devices used to incinerate municipal solid waste. The waste burns inside the furnace, pyrolyzing the organic matter. Direct incineration produces highly complex flue gas containing combustible mixtures such as carbon monoxide and hydrogen, as well as toxic and harmful gases like dioxins and nitrogen oxides. Direct emission of these gases would severely impact the surrounding environment. Therefore, the flue gas is usually transported to a secondary combustion chamber for re-combustion to fully decompose the toxic and harmful gases. Chinese invention patent application CN110260325A provides a multi-layer, multi-cavity in-furnace combustion furnace. This furnace has multiple combustion chambers arranged vertically within the furnace body, allowing the flue gas to pass through each chamber sequentially for thermal decomposition. However, this furnace only has a heat storage element in the lowest combustion chamber. The combustible mixture after ignition is drawn out by the negative pressure at the furnace outlet. Insufficient combustible mixture in other combustion chambers can easily lead to excessively low temperatures, affecting the complete combustion of the combustible mixture in those chambers and reducing their combustion efficiency. Utility Model Content

[0003] The purpose of this invention is to provide a secondary combustion chamber to solve the problems existing in the prior art. It can keep the temperature in each combustion chamber stable, avoid the temperature in each combustion chamber from being too low, enable the gas to burn completely, and improve the combustion efficiency in each combustion chamber.

[0004] To achieve the above objectives, this utility model provides the following solution:

[0005] This utility model provides a secondary combustion chamber, including a combustion chamber with a smoke inlet and a smoke outlet. The combustion chamber includes a plurality of sequentially connected combustion chambers disposed between the smoke inlet and the smoke outlet. The smoke inlet and the smoke outlet are both connected to each of the combustion chambers. The smoke outlet is connected to an induced draft device. Each of the combustion chambers is provided with a heat storage body. A burner is provided in the two combustion chambers near the smoke inlet. A denitrification device is provided in the combustion chamber near the smoke outlet.

[0006] In some embodiments, a plurality of heat storage bodies are provided in each of the combustion chambers, and any adjacent heat storage bodies in each combustion chamber are arranged at intervals.

[0007] In some embodiments, an oxygenation device is provided at the smoke inlet. The oxygenation device includes a first gas chamber, with a first air inlet and an air outlet at both ends of the first gas chamber along its axial direction. A second air inlet is provided on the side wall of the first gas chamber. The first air inlet is used to receive flue gas. One end of the second air inlet is an air inlet end, and the other end is an air outlet end. The shape of the second air inlet is partially spiral, and the air outlet end is closer to the air outlet end than the air inlet end along the axial direction of the first gas chamber. The air outlet end communicates with the smoke inlet.

[0008] In some embodiments, the oxygen supply device further includes a second gas chamber, which has multiple second air inlets. The second gas chamber is located outside the first gas chamber, and a third air inlet is provided on the second gas chamber to connect the outside to the inside of the second gas chamber.

[0009] In some embodiments, the combustion chamber is provided with three chambers: a first combustion chamber, a second combustion chamber, and a third combustion chamber. The flue gas inlet is connected to the first combustion chamber, the second combustion chamber is connected to the end of the first combustion chamber away from the flue gas inlet, and the third combustion chamber is connected to the end of the second combustion chamber away from the first combustion chamber. A removable preheater is also provided on the side wall of the first combustion chamber. The removable preheater can switch between a first position and a second position. When the removable preheater is in the first position, it can be energized to preheat the gas in the first combustion chamber. When the removable preheater is in the second position, it is retracted from the first combustion chamber.

[0010] In some embodiments, an oxygen supply device is also included, which is used to supply oxygen to the oxygen intake device and the combustion chamber.

[0011] In some embodiments, the oxygen supply device includes an oxygen supply pipe, which is partially disposed within the side wall of the combustion chamber, and the gas in the combustion chamber can heat the oxygen in the oxygen supply pipe disposed within the side wall of the combustion chamber during combustion.

[0012] In some embodiments, there are three oxygen supply pipes, namely a first oxygen supply pipe, a second oxygen supply pipe, and a third oxygen supply pipe. One end of the first oxygen supply pipe, the second oxygen supply pipe, and the third oxygen supply pipe is used to introduce oxygen. The other end of the first oxygen supply pipe is used to communicate with the third air inlet. The other end of the second oxygen supply pipe is used to communicate with the end of the second combustion chamber near the first combustion chamber. The other end of the third oxygen supply pipe is used to communicate with the third combustion chamber.

[0013] In some embodiments, the combustion chamber sidewall includes a refractory layer, a thermal insulation layer, and a corrosion-resistant layer arranged sequentially from the inside to the outside.

[0014] In some embodiments, a temperature measuring device is provided in each of the combustion chambers to measure the temperature inside the combustion chamber.

[0015] The present invention achieves the following technical advantages over the prior art:

[0016] The secondary combustion chamber provided by this utility model allows a combustible mixture to be introduced through the flue gas inlet. After combustion within the combustion chamber, the combustible mixture is discharged through the flue gas outlet. The combustion chamber includes multiple sequentially connected combustion chambers located between the flue gas inlet and the flue gas outlet. By installing heat storage bodies in each combustion chamber, when the pyrolysis flue gas in the combustion chamber is insufficient, the heat released by the heat storage bodies keeps the temperature in each combustion chamber stable, preventing the temperature in the combustion chamber from becoming too low, and ensuring that the gas in each combustion chamber can be fully combusted, thereby improving the combustion efficiency of each combustion chamber. Furthermore, by using two heat storage bodies near the flue gas inlet... Each combustion chamber is equipped with a burner. On the one hand, when the secondary combustion chamber is started, the combustible mixture introduced into the combustion chamber can be ignited multiple times to quickly raise the temperature in the combustion chamber to above 850°C, so that pollutants such as dioxins can be fully pyrolyzed. On the other hand, if the calorific value in the combustion chamber is too low to reach 850°C during combustion, the burner can be selectively turned on to assist combustion and increase the temperature in the combustion chamber. Furthermore, by installing a denitrification device in the combustion chamber near the flue gas outlet, nitrogen oxides are converted into harmless nitrogen and water, thereby improving the exhaust gas quality. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a cross-sectional view of the combustion chamber structure in one embodiment of the present invention;

[0019] Figure 2 This is a schematic diagram of the combustion chamber structure in one embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of the oxygen supply device in one embodiment of the present invention;

[0021] In the diagram: 1-Combustion chamber; 11-Smoke inlet; 12-Smoke outlet; 2-Combustion chamber body; 21-First combustion chamber body; 22-Second combustion chamber body; 23-Third combustion chamber body; 3-Heat regenerator; 31-Denitrification device; 4-Burner; 5-Oxygen supply device; 51-First gas chamber; 52-First air inlet; 53-Second air inlet; 54-Air outlet; 55-Second gas chamber; 56-Third air inlet; 6-Removable preheater; 7-Oxygen supply device; 71-Oxygen supply pipe; 72-Oxygen supply fan; 81-Temperature measuring device; 82-Fire observation window; 83-Inspection door. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] The purpose of this invention is to provide a secondary combustion chamber to solve the problems existing in the prior art. It can keep the temperature in each combustion chamber stable, avoid the temperature in each combustion chamber from being too low, enable the gas to burn completely, and improve the combustion efficiency in each combustion chamber.

[0024] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] This utility model provides a secondary combustion chamber, such as Figures 1-3As shown, the system includes a combustion chamber 1 with an inlet 11 and an outlet 12. The combustion chamber 1 includes multiple sequentially connected combustion chambers 2 located between the inlet 11 and the outlet 12. Both the inlet 11 and the outlet 12 are connected to each combustion chamber 2, and the outlet 12 is connected to an induced draft device. The induced draft device provides negative pressure to each combustion chamber. Each combustion chamber 2 contains a heat storage body 3. A burner 4 is installed in the two combustion chambers closest to the inlet 11, and a denitrification device 31 is installed in the combustion chamber closest to the outlet 12. By installing heat storage bodies in each combustion chamber, when the pyrolysis flue gas in the combustion chamber is insufficient, the heat released by the heat storage bodies keeps the temperature in each combustion chamber stable, preventing combustion. The low temperature within the combustion chamber ensures complete combustion of the gases in each chamber, improving combustion efficiency. Furthermore, by installing burners in both combustion chambers near the flue gas inlet, the combustible mixture entering the secondary combustion chamber can be ignited multiple times during startup, rapidly raising the temperature within the combustion chamber to above 850°C for complete pyrolysis of pollutants such as dioxins. Additionally, if the calorific value within the combustion chamber is too low to reach 850°C during combustion, the burners can be selectively activated to assist combustion and increase the temperature within the combustion chamber. Finally, a denitrification device is installed in the combustion chamber near the flue gas outlet to convert nitrogen oxides into harmless nitrogen and water, improving the quality of exhaust emissions.

[0026] In some embodiments of this utility model, the induced draft device is an induced draft fan, and a flue gas purification system is also provided between the induced draft fan and the flue gas outlet 12 to further purify the gas discharged from the combustion chamber 1.

[0027] In some embodiments of this utility model, the heat storage body is a honeycomb ceramic heat storage body. The honeycomb structure of the honeycomb ceramic heat storage body can play a filtering role, effectively intercepting large particulate matter in the flue gas and improving the emission quality of the exhaust gas.

[0028] In some embodiments of this utility model, the denitrification device is a selective non-catalytic reduction (SNCR) denitrification device. SNCR denitrification technology is a denitrification process applied in the process of waste pyrolysis incineration. Its principle is to inject a reducing agent such as ammonia or urea into the relatively stable high-temperature zone (850℃-1100℃) near the flue gas outlet 12 of the secondary combustion chamber, so as to react with nitrogen oxides (NOx) in the flue gas to generate nitrogen and water, thereby improving the emission quality of the exhaust gas.

[0029] In some embodiments of this invention, the selective non-catalytic reduction (SNCR) denitrification device is made of high-temperature resistant 310s stainless steel to improve the heat resistance of the device.

[0030] In some embodiments of this utility model, such as Figure 1 As shown, multiple heat storage bodies 3 are provided in each combustion chamber 2. Any adjacent heat storage bodies 3 in each combustion chamber 2 are arranged at intervals to increase the contact area between the heat storage bodies 3 and the combustion gas in the combustion chamber 2, thereby further improving the combustion efficiency of each combustion chamber 2 and the interception effect of large particles.

[0031] In some embodiments of this utility model, such as Figure 3 As shown, an oxygenation device 5 is provided at the smoke inlet 11. The oxygenation device 5 includes a first gas chamber 51. A first air inlet 52 and an air outlet 54 are respectively provided at both ends of the first gas chamber 51 along its axial direction. A second air inlet 53 is provided on the side wall of the first gas chamber 51. One end of the second air inlet 53 is the air inlet end, and the other end is the air outlet end. The shape of the second air inlet 53 is partially spiral, and the air outlet end is closer to the air outlet 54 than the air inlet end along the axial direction of the first gas chamber 51. The air outlet 54 communicates with the smoke inlet 11. The first air inlet 52 is used to receive flue gas, and the second air inlet 53 is used to receive oxygen. The gas is circulated and oxygen is generated in the first gas chamber 51 to form a vortex-like airflow. The flue gas and oxygen are mixed in the first gas chamber 51 to form a combustible mixture. The gas outlet 54 is used to introduce the combustible mixture into the first combustion chamber 21. By introducing the vortex-like oxygen into the first gas chamber 51, the oxygen and flue gas are fully mixed in the first gas chamber 51, giving full play to the role of oxygen in assisting combustion. After ignition, a vortex-like flame can be formed. The centrifugal force and backflow zone formed by the vortex-like flame can resist the disturbance caused by changes in external airflow pressure, making the gas combustion more stable and increasing the temperature in the combustion chamber.

[0032] In some embodiments of this utility model, the oxygen supply device 5 is made of high-temperature resistant 310s stainless steel to improve the heat resistance of the oxygen supply device 5.

[0033] In some embodiments of this utility model, such as Figure 3 As shown, the oxygen supply device 5 also includes a second gas chamber 55, with multiple second air inlets. The second gas chamber 55 is located outside the first gas chamber 51. The second gas chamber 55 is provided with a third air inlet 56 that connects the outside to the inside of the second gas chamber 55. The third air inlet 56 is used to receive oxygen. The oxygen in the second gas chamber 55 is introduced into the first gas chamber 51 through the second air inlet 53. Through the second gas chamber 55, the oxygen flow rate through each second air inlet 53 is made more uniform.

[0034] In some embodiments of this utility model, such as Figure 3As shown, the second air inlet 53 is evenly distributed along the axial and circumferential edges of the first gas chamber 51 so that the oxygen introduced into the first gas chamber 51 is evenly distributed within the first gas chamber 51, so that the combustion is more uniform after the gas is introduced into the first combustion chamber 21, reducing the amount of unburned combustible mixture.

[0035] In some embodiments of this utility model, such as Figure 1 As shown, the combustion chamber 2 is provided with three chambers: a first combustion chamber 21, a second combustion chamber 22, and a third combustion chamber 23. The smoke inlet 11 is connected to the first combustion chamber 21. The second combustion chamber 22 is connected to the end of the first combustion chamber 21 away from the smoke inlet 11. The third combustion chamber 23 is connected to the end of the second combustion chamber 22 away from the first combustion chamber 21. A removable preheater 6 is also provided on the side wall of the first combustion chamber 21. The removable preheater 6 can switch between a first position and a second position. When the removable preheater 6 is in the first position, the removable preheater 6... The system can be powered on to preheat the gas in the first combustion chamber 21. When the removable preheater 6 is in the second position, it is pulled out of the first combustion chamber 21. Before combustion, the removable preheater 6 is in the first position to heat the combustible mixture introduced into the first combustion chamber 21, thereby increasing the temperature in the first combustion chamber 21 and reducing the water vapor content in the flue gas, making it easier for the burner 4 to ignite the gas. After preheating to the set temperature, the removable preheater 6 is pulled back to avoid damage to the removable preheater 6 during combustion.

[0036] In some embodiments of this utility model, the outer wall of the pull-out movable preheater 6 is made of high-temperature resistant 310S stainless steel, and the interior is made of refractory material.

[0037] In some embodiments of this utility model, the pull-out movable preheater 6 can preheat the combustible mixture to 800~900°C, so that the burner can ignite the gas more easily.

[0038] In some embodiments of this utility model, the pull-out movable preheater 6 is a resistance wire preheater. The voltage across the resistance wire can be adjusted to control the heating temperature of the pull-out movable preheater 6. The resistance wire is made of tungsten-nickel alloy, nickel-chromium alloy, or iron-chromium-aluminum alloy, which are resistant to high temperature, have high resistivity, and are corrosion resistant.

[0039] In some embodiments of this utility model, such as Figure 1 As shown, the secondary combustion chamber also includes an oxygen supply device 7, which is used to introduce oxygen into the oxygen supply device 5 and the combustion chamber 1. The oxygen mixes with the flue gas to form a gas, and the oxygen can improve the combustion efficiency and temperature.

[0040] In some embodiments of this utility model, such as Figure 1 As shown, the oxygen supply device 7 includes an oxygen supply pipe 71, which is installed inside the side wall of the combustion chamber 1. When the gas in the combustion chamber 1 is burning, it can heat the oxygen in the oxygen supply pipe 71 installed inside the side wall of the combustion chamber, thereby giving the oxygen introduced into the oxygen supply device 5 and the combustion chamber 1 a higher temperature, making the flue gas combustion more stable.

[0041] In some embodiments of this utility model, such as Figure 1 As shown, there are three oxygen supply pipes 71, namely the first oxygen supply pipe, the second oxygen supply pipe, and the third oxygen supply pipe. One end of the first, second, and third oxygen supply pipes is used to introduce oxygen. The other end of the first oxygen supply pipe is used to connect with the third air inlet 56 to introduce oxygen into the oxygen supply device 5. The other end of the second oxygen supply pipe is used to connect with the end of the second combustion chamber 22 near the first combustion chamber 21 to add oxygen to the gas flowing from the first combustion chamber 21 to the second combustion chamber 22, making it easier for the burner 4 to ignite the gas. The other end of the third oxygen supply pipe is used to connect with the third combustion chamber 23 to supplement the oxygen content in the third combustion chamber 23, so that the gas can be fully burned in the third combustion chamber 23.

[0042] In some embodiments of this utility model, such as Figure 1 As shown, the oxygen supply pipes 1, 2 and 3 are connected to a variable frequency oxygenation fan 72 at the end for introducing oxygen. The oxygen supply is adjusted by controlling the variable frequency oxygenation fan 72. Valves are installed on the first, second and third oxygen supply pipes. The oxygen supply of each oxygen supply pipe is adjusted by controlling the opening degree of the valves.

[0043] In some embodiments of this utility model, the side wall of the combustion chamber 1 includes a fire-resistant layer, a heat-insulating layer and a corrosion-resistant layer arranged sequentially from the inside to the outside.

[0044] In some embodiments of this utility model, such as Figure 1 As shown, a temperature measuring device 81 is installed in each combustion chamber 2 to measure the temperature inside the combustion chamber 2. When the temperature is low, the temperature inside the combustion chamber 2 is increased by increasing the oxygen supply.

[0045] In some embodiments of this utility model, the temperature measuring device 81 is a thermocouple, which converts thermal energy into electrical energy signals to achieve accurate temperature monitoring of high-temperature objects or environments.

[0046] In some embodiments of this utility model, such as Figure 1As shown, a viewing mirror 82 is provided on the side wall of the first combustion chamber 21 to visually inspect the combustion state inside the first combustion chamber 21, and to control the oxygen supply of the variable frequency oxygenation fan 72 and the oxygen supply of each oxygen supply pipe according to the combustion state.

[0047] In some embodiments of this utility model, such as Figure 1 As shown, each combustion chamber 2 has an inspection port on its side wall, and an openable inspection door 83 is connected to the inspection port to facilitate maintenance work.

[0048] This utility model uses specific examples to illustrate its principles and implementation methods. The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the idea of ​​this utility model. In summary, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A secondary combustion chamber, characterized by, The application relates to a combustion chamber, which comprises an inlet and an outlet, and a plurality of combustion cavities arranged in sequence between the inlet and the outlet, wherein the inlet and the outlet are communicated with each of the combustion cavities, the outlet is communicated with an air induction device, each of the combustion cavities is provided with a heat storage body, two combustion machines are arranged in the combustion cavities close to the inlet, and a denitration device is arranged in the combustion cavity close to the outlet.

2. The secondary combustion chamber of claim 1, wherein A plurality of heat storage bodies are arranged in each of the combustion cavities, and any adjacent heat storage bodies in each of the combustion cavities are arranged at intervals.

3. The secondary combustion chamber of claim 1, wherein An oxygen-increasing air inlet device is arranged at the inlet, and the oxygen-increasing air inlet device comprises a first gas cavity, the two axial ends of the first gas cavity are respectively provided with a first air inlet hole and an air outlet hole, the side wall of the first gas cavity is provided with a second air inlet hole, the first air inlet hole is used for receiving flue gas, one end of the second air inlet hole is an air inlet end, and the other end is an air outlet end, the second air inlet hole is partially spiral-shaped, the air outlet end is closer to the air outlet hole than the air inlet end in the axial direction of the first gas cavity, and the air outlet hole is communicated with the inlet.

4. The secondary combustion chamber of claim 3, wherein The oxygen-increasing air inlet device further comprises a second gas cavity, a plurality of second air inlet holes are arranged, the second gas cavity is arranged outside the first gas cavity, and the second gas cavity is provided with a third air inlet hole communicated between the outside and the inside of the second gas cavity.

5. The secondary combustion chamber of claim 4, wherein The combustion chamber is provided with three combustion cavities, namely a first combustion cavity, a second combustion cavity and a third combustion cavity, the inlet is communicated with the first combustion cavity, the second combustion cavity is communicated with one end of the first combustion cavity away from the inlet, the third combustion cavity is communicated with one end of the second combustion cavity away from the first combustion cavity, and a pullable movable preheater is further arranged on the side wall of the first combustion cavity, the pullable movable preheater can be switched between a first position and a second position, when the pullable movable preheater is in the first position, the pullable movable preheater can be electrified to preheat the gas in the first combustion cavity, and when the pullable movable preheater is in the second position, the pullable movable preheater is pulled back from the first combustion cavity.

6. The secondary combustion chamber of claim 5, wherein The application further comprises an oxygen supply device, which is used for supplying oxygen into the oxygen-increasing air inlet device and the combustion chamber.

7. The secondary combustion chamber of claim 6, wherein The oxygen supply device comprises an oxygen supply pipe, the oxygen supply pipe is partially arranged in the side wall of the combustion chamber, and the gas in the combustion chamber can heat the oxygen in the oxygen supply pipe arranged in the side wall of the combustion chamber during combustion.

8. The secondary combustion chamber of claim 7, wherein The oxygen supply pipe has three oxygen supply pipes, namely a first oxygen supply pipe, a second oxygen supply pipe and a third oxygen supply pipe, one end of each of the first oxygen supply pipe, the second oxygen supply pipe and the third oxygen supply pipe is used for supplying oxygen, the other end of the first oxygen supply pipe is used for being communicated with the third air inlet hole, the other end of the second oxygen supply pipe is used for being communicated with one end of the second combustion cavity close to the first combustion cavity, and the other end of the third oxygen supply pipe is used for being communicated with the third combustion cavity.

9. The secondary combustion chamber of claim 1, wherein The side wall of the combustion chamber comprises, from inside to outside, a fireproof layer, a heat preservation layer and a corrosion resistant layer.

10. The secondary combustion chamber of claim 1, wherein Temperature measuring devices are arranged in each of the combustion cavities to measure the temperature in the combustion cavities.

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