A composite dechlorination domestic waste gasification treatment system

Abstract

The present invention relates to a composite dechlorination system for treating domestic waste gasification, comprising a gasifier and a composite dechlorination system. The composite dechlorination system comprises a chlorine coarse filtration device and a cyclone separator dechlorination device. The chlorine coarse filtration device comprises a plurality of filter plates arranged from top to bottom within the gasifier, and a calcium injection port disposed on the gasifier. One end of the filter plate is connected to the gasifier, and the filter plate is arranged to tilt downward from a fixed end to a free end. The gasifier comprises a gasification reaction layer and a filter layer for accommodating the chlorine coarse filtration device. The filter layer is disposed on top of the gasification reaction layer, and the calcium injection port is disposed at the gasification reaction layer. The present invention provides a composite dechlorination system for treating domestic waste gasification, which directly dechlorinates the combustible gas after it is generated in the gasifier, thereby preventing high-temperature corrosion of subsequent equipment by the combustible gas, thereby improving steam parameters and power generation efficiency, and helping to reduce the low-temperature heterogeneous catalytic synthesis of dioxins during flue gas cooling.

Description

Technical Field

[0001] The present invention relates to a domestic waste gasification treatment system, in particular to a domestic waste gasification treatment system with composite dechlorination. Background Art

[0002] The treatment and disposal of domestic waste and other wastes is a major problem that my country urgently needs to solve. Among them, incineration power generation technology has the advantages of high degree of harmlessness, significant volume and weight reduction effects, and energy recovery and utilization. It has been rapidly developed and applied in recent years. However, during the incineration process of domestic waste, secondary pollutants will inevitably be produced, especially chlorine-containing pollutants such as dioxins and hydrogen chloride (HCl), which pose a great threat to the environment and human health. On the one hand, the chlorine contained in domestic waste mainly forms HCl after incineration, and its content in the waste incineration flue gas can reach 800-1800 mg / Nm 3 , is one of the main causes of acid rain, and because HCl can easily cause high-temperature corrosion of equipment, it limits the steam parameters of waste incineration power generation (generally not higher than 400 o C, 4 MPa), resulting in power generation efficiency of only around 20%, far lower than that of coal-fired power plants. Furthermore, HCl in incineration flue gas, acting as a chlorine source, directly or indirectly plays a key role in dioxin formation during flue gas cooling. Therefore, addressing emission control issues, such as those related to chlorine-containing pollutants, is both a key and challenging issue in the current development of waste incineration technology.

[0003] The "two-step" waste incineration technology based on pyrolysis and gasification of domestic waste and combustion of combustible gas has outstanding advantages in reducing pollution emissions and improving power generation efficiency. The product of pyrolysis and gasification of waste is combustible gas, which can be pre-treated by dechlorination and other purification processes before combustion, thereby reducing the HCl content in the incineration flue gas and reducing the low-temperature heterogeneous catalytic synthesis of dioxins during the flue gas cooling process, effectively solving the problem that traditional waste incineration can only remove pollutants through low-temperature tail gas purification devices. And because the removal of HCl in the combustible gas can solve the problem of corrosion on the flue gas heating surface after incineration, the subsequent power generation system can use high steam parameters (such as 540 o C, 12 MPa), significantly improving power generation efficiency. However, solely using post-dechlorination technology for medium- and high-temperature combustible gas is associated with low efficiency, high dechlorination agent usage, and high dechlorination costs. Therefore, it is necessary to develop a system and method for removing chlorine-containing pollutants from the pyrolysis and gasification process of municipal solid waste, combining the characteristics of the pyrolysis and gasification reaction with the technological advantages to achieve deep dechlorination of combustible gas. Summary of the Invention

[0004] The present invention mainly solves the technical problems existing in the prior art that HCl can only be removed through a low-temperature tail gas purification device, which easily causes high-temperature corrosion of the equipment, thereby limiting the steam parameters of waste incineration power generation, resulting in a low power generation rate, and easily directly or indirectly causing the generation of dioxins during the flue gas cooling process. The present invention provides a domestic waste gasification treatment system that directly and deeply dechlorinates the combustible gas after it is generated in a gasifier, thereby avoiding high-temperature corrosion of subsequent equipment by the combustible gas, thereby improving steam parameters and power generation efficiency, and helping to reduce the low-temperature heterogeneous catalytic synthesis of dioxins during the flue gas cooling process.

[0005] In order to solve the above technical problems and achieve the above invention objectives, the present invention provides a composite dechlorination domestic waste gasification treatment system, including a gasifier and a composite dechlorination system, characterized in that the composite dechlorination system includes a chlorine coarse filtration device and a cyclone separator dechlorination device, the chlorine coarse filtration device includes a plurality of filter plates arranged from top to bottom in the gasifier and a calcium spraying port provided on the gasifier, one end of the filter plate is connected to the gasifier, and the filter plate is arranged downwardly from the fixed end to the free end, the gasifier includes a gasification reaction layer and a filter layer for placing the chlorine coarse filtration device, the filter layer is provided on the top of the gasification reaction layer, and the calcium spraying port is provided at the gasification reaction layer.

[0006] As an optimization of the composite dechlorination domestic waste gasification treatment system of the present invention, the cyclone separator dechlorination device includes a cyclone separator connected to the gas outlet of the gasifier, and a plurality of dechlorination agent nozzles are provided on the top of the cyclone separator, and the dechlorination agent nozzles are connected to the first dechlorination agent bin through a first blower.

[0007] As an optimization of the composite dechlorination domestic waste gasification treatment system of the present invention, the filter plate includes a left filter plate arranged on the left side of the gasifier and a right filter plate arranged on the right side of the gasifier. The left filter plate and the right filter plate are staggered from top to bottom in the gasifier to form an arched baffle area. The two adjacent left filter plates and the right filter plates above and below constitute a single filtration cycle, and a plurality of filtration cycles are provided in the gasifier.

[0008] As an optimization of the composite dechlorination domestic waste gasification treatment system of the present invention, the filter plate is a flat filter plate, and the filter plate is rotatably connected to the gasification furnace through a rotating device. The rotating device includes a rotating shaft connected to the filter plate and a rotating motor, and the rotating motor is connected to the rotating shaft.

[0009] As an optimization of the composite dechlorination domestic waste gasification treatment system of the present invention, the left filter plate and the right filter plate form an angle of 30°-70° with the horizontal plane.

[0010] As an optimization of the composite dechlorination domestic waste gasification treatment system of the present invention, the calcium injection port is connected to a calcium injection conduit, one end of the calcium injection conduit is connected to a calcium injection nozzle in the gasification furnace, and the calcium injection conduit is connected to the second dechlorination agent bin through a second blower.

[0011] As an optimization of the composite dechlorination domestic waste gasification treatment system of the present invention, the calcium injection conduit is arranged to be inclined downward.

[0012] As an optimization of the composite dechlorination domestic waste gasification treatment system of the present invention, the longitudinal orthographic projections of the left filter plate and the right filter plate do not intersect.

[0013] Compared with the prior art, the domestic waste gasification treatment system with chlorine removal function of the present invention has the following beneficial effects:

[0014] 1. Preheat the gasifier. When the temperature of the gasifier reaches 500℃, the gasification medium first enters the gasifier through the air distribution plate. Then the dried domestic waste is crushed and fed into the gasifier through the feeding device, so that the gasification medium and domestic waste are quickly mixed to generate a large amount of heat, and the incomplete reaction produces crude gas. The reaction temperature is controlled at 750℃. The important components of the crude gas are CO, CO2, H2, CH4, HCl, H2O and solid particles. Calcium is sprayed into the furnace through the calcium spray port for dechlorination. After the domestic waste is dechlorinated by calcium spraying, due to the presence of the gasification medium, the calcium-based dechlorinating agent rises continuously with the crude gas and encounters a filter plate that tilts downward from the fixed end to the free end. The fixed particles and calcium-based dechlorinating agent of the rising crude gas are precipitated and roughly removed to prevent the solid particles and calcium-based dechlorinating agent in the crude gas from continuing to rise. The precipitated calcium-based dechlorinating agent After precipitation, it flows back to the gasification reaction layer to form secondary dechlorination in the furnace, which reduces the use of dechlorination agent and reduces the dechlorination cost. The raw gas is subjected to coarse filtration of chlorine and solid particles by the coarse filtration device of the gasifier and then enters the cyclone separator, so that the raw gas is fully mixed with the calcium-based dechlorination agent, thereby forming a composite filtration to achieve deep dechlorination of the combustible gas, avoid high-temperature corrosion of the combustible gas to subsequent equipment, improve the power generation rate, and reduce the low-temperature heterogeneous synthesis of dioxins during the flue gas cooling process. The reduction of the solid particle content in the raw gas reduces impurities after the raw gas enters the cyclone separator and is fully mixed with the calcium-based dechlorination agent, thereby improving the dechlorination efficiency. The solid particles and calcium-based dechlorination agent in the raw gas are precipitated and removed by the chlorine coarse filtration device. After precipitation and removal, the solid particles and calcium-based defluorination agent can be discharged together with the gasification bottom slag, simplifying the subsequent treatment steps for the solid particles.

[0015] 2. The purpose of combining the chlorine fine filtration with the cyclone separator installed outside the gasifier is to avoid the removal of chlorine at high temperatures in the brain, thereby achieving medium-high temperature dechlorination of the crude gas (medium-high temperature dechlorination technology refers to the technology of using a solid-phase dechlorination agent to absorb HCl gas in the crude gas at a temperature greater than 500°C to ultimately achieve the separation and removal of chlorine-containing pollutants in the flue gas). This avoids the reduction of the chlorine removal effect of the device due to excessively high temperatures in the gasifier, thereby improving the filtration efficiency of the chlorine fine filtration device;

[0016] 3. The first blower delivers the dechlorinating agent in the first dechlorinating agent bin to the cyclone separator. Due to the high-speed vortex generated by the crude gas in the cyclone separator, the dechlorinating agent can quickly diffuse under the action of the vortex and come into contact with the hydrogen sulfide in the flue gas to produce a chemical reaction, thereby removing chlorine;

[0017] 4. The filter plates include a left filter plate located on the left side of the gasifier and a right filter plate located on the right side of the gasifier. The left filter plate and the right filter plate are staggered from top to bottom in the gasifier to form an arcuate baffle area. The two adjacent left and right filter plates above and below constitute a single filtration cycle. The purpose of providing several filtration cycles in the gasifier is to form an arcuate baffle in the filter layer for the crude gas, thereby enhancing the efficiency of removing solid particles from the crude gas.

[0018] 5. The filter plate is rotatably connected to the gasifier via a rotating device. The rotating device includes a rotating shaft connected to the filter plate and a rotating motor. The rotating motor is connected to the rotating shaft and is used to remove impurities accumulated on the filter plate by periodically rotating the rotating device.

[0019] 6. The second blower sprays the dechlorinating agent in the second dechlorinating agent bin into the gasifier through the calcium injection conduit, thereby causing a dechlorination reaction on the domestic waste in the gasifier;

[0020] 7. The purpose of setting the calcium spray conduit downward is to effectively spray the dechlorination agent on the garbage, further reducing the chlorine content in the crude gasification gas;

[0021] 8. The purpose of the non-intersection of the longitudinal projections of the left filter plate and the right filter plate is to avoid local congestion of the crude gas between the left filter plate and the right filter plate, thereby affecting the filtering effect.

[0022] Therefore, the present invention has the characteristics of reasonable structure, high efficiency and energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attachment Figure 1 This is a flow diagram of the crude gasification gas of the present invention;

[0024] Attachment Figure 2 This is a structural diagram of the present invention when removing impurities;

[0025] Attachment Figure 3 It is a front view of the dechlorination agent nozzle of the present invention.

[0026] Part number description in the figure: 1. Gasification furnace, 2. Calcium injection port, 3. Fixed end, 4. Free end, 5. Gasification reaction layer, 6. Filter layer, 7. Cyclone separator, 8. Dechlorination agent nozzle, 9. Left filter plate, 10. Right filter plate, 11. Rotating shaft, 12. Calcium injection guide tube, 13. Calcium injection nozzle. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0028] Example 1:

[0029] according to Figure 1 The composite dechlorination system for treating domestic waste by gasification is shown, comprising a gasifier 1 and a composite dechlorination system, characterized in that the composite dechlorination system comprises a chlorine coarse filtration device and a cyclone separator 7 dechlorination device, the chlorine coarse filtration device comprising a plurality of filter plates arranged from top to bottom in the gasifier 1 and a calcium injection port 2 arranged on the gasifier 1, one end of the filter plate is connected to the gasifier 1, and the filter plate is arranged downwardly inclined from the fixed end 3 to the free end 4, the gasifier 1 comprises a gasification reaction layer 5 and a filter layer 6 for placing the chlorine coarse filtration device, the filter layer 6 is arranged at the top of the gasification reaction layer 5, and the calcium injection port 2 is arranged at the gasification reaction layer 5.

[0030] The gasifier 1 is preheated, and when the temperature of the gasifier 1 reaches 500°C, the gasification medium first enters the gasifier 1 through the air distribution plate, and then the dried domestic garbage is crushed and fed into the gasifier 1 through the feeding device, so that the gasification medium and the domestic garbage are quickly mixed to generate a large amount of heat, and the incomplete reaction produces crude gasification gas, and the reaction temperature is controlled at 750°C. The important components of the crude gasification gas are CO, CO2, H2, CH4, HCl, H2O and solid particles, and calcium is sprayed into the furnace for dechlorination through the calcium spray port 2. After the domestic garbage is sprayed with calcium for dechlorination, due to the presence of the gasification medium, the calcium-based dechlorination agent rises continuously with the crude gasification gas and encounters the filter plate tilted downward from the fixed end 3 to the free end 4. The fixed particles and calcium-based dechlorination agent of the rising crude gasification gas are precipitated and roughly removed to prevent the solid particles and calcium-based dechlorination agent in the crude gasification gas from continuing to rise. The precipitated calcium-based dechlorination agent After precipitation, the agent flows back to the gasification reaction layer 5, forming secondary dechlorination in the furnace, reducing the use of dechlorination agent and reducing the dechlorination cost. The raw gas passes through the coarse filtration device of the gasifier 1 to filter the chlorine and solid particles and then enters the cyclone separator 7, so that the raw gas is fully mixed with the calcium-based dechlorination agent, thereby forming a composite filtration to achieve deep dechlorination of the combustible gas, avoid high-temperature corrosion of the combustible gas to subsequent equipment, improve the power generation rate, and reduce the low-temperature heterogeneous synthesis of dioxins in the flue gas cooling process. The reduction of the solid particle content in the raw gas reduces impurities after the raw gas enters the cyclone separator 7, and is fully mixed with the calcium-based dechlorination agent, thereby improving the dechlorination efficiency. The solid particles and calcium-based dechlorination agent in the raw gas are precipitated and removed by the chlorine coarse filtration device. After precipitation and removal, the solid particles and calcium-based defluorination agent can be discharged together with the gasification bottom ash, simplifying the subsequent processing steps for the solid particles.

[0031] Example 2:

[0032] according to Figure 1 and Figure 3 As shown, the difference between this embodiment and embodiment 1 is that the cyclone separator 7 dechlorination device includes a cyclone separator 7 connected to the gas outlet of the gasifier 1, and a plurality of dechlorination agent nozzles 8 are provided on the top of the cyclone separator 7. The dechlorination agent nozzles 8 are connected to the first dechlorination agent bin through the first blower.

[0033] Compared with Example 1, this embodiment further defines the dechlorination device of the cyclone separator 7. The purpose of combining the fine filtration of chlorine with the cyclone separator 7 arranged outside the gasifier 1 is to avoid the removal of chlorine at high temperature in the brain, thereby realizing medium- and high-temperature dechlorination of the crude gas (medium- and high-temperature dechlorination technology refers to the technology of using a solid-phase dechlorination agent to absorb HCl gas in the crude gas within a temperature range greater than 500°C to ultimately achieve the separation and removal of chlorine-containing pollutants in the flue gas). This avoids the reduction of the dechlorination effect of the device due to excessively high temperature in the gasifier 1, thereby improving the filtration efficiency of the chlorine fine filtration device. The dechlorination agent in the first dechlorination agent bin is sent to the cyclone separator 7 by the first blower. Since the crude gas in the cyclone separator 7 generates a high-speed vortex, the dechlorination agent can quickly diffuse under the action of the vortex and contact with hydrogen sulfide in the flue gas to produce a chemical reaction, thereby removing chlorine.

[0034] Example 3:

[0035] according to Figures 1 to 2 As shown, the difference between this embodiment and embodiment 1 is that the filter plate includes a left filter plate 9 arranged on the left side of the gasifier 1 and a right filter plate 10 arranged on the right side of the gasifier 1. The left filter plate 9 and the right filter plate 10 are staggered from top to bottom in the gasifier 1 to form an arched deflection area. The two adjacent left filter plates 9 and right filter plates 10 above and below form a single filtration cycle. A plurality of filtration cycles are provided in the gasifier 1.

[0036] Compared with Example 1, this embodiment makes further restrictions on the filter plate. The filter plate includes a left filter plate 9 arranged on the left side of the gasifier 1 and the right filter plate 10 arranged on the right side of the gasifier 1. The left filter plate 9 and the right filter plate 10 are staggered from top to bottom in the gasifier 1 to form an arched deflection area. The two adjacent left filter plates 9 and right filter plates 10 above and below constitute a single filtration cycle. The function of providing several filtration cycles in the gasifier 1 is to make the crude gasify gas form an arched deflection in the filter layer 6, thereby enhancing the efficiency of removing solid particles from the crude gasify gas.

[0037] Example 4:

[0038] according to Figures 1 to 2 As shown, the difference between this embodiment and embodiment 1 is that the filter plate is a flat filter plate, and the filter plate is rotatably connected to the gasification furnace 1 through a rotating device. The rotating device includes a rotating shaft 11 connected to the filter plate and a rotating motor, and the rotating motor is connected to the rotating shaft 11.

[0039] Compared with Example 1, this embodiment further defines the filter plate. The filter plate is rotatably connected to the gasifier 1 through a rotating device. The rotating device includes a rotating shaft 11 connected to the filter plate and a rotating motor. The function of the rotating motor connected to the rotating shaft 11 is to regularly remove impurities accumulated on the filter plate by rotating the rotating device.

[0040] Example 5:

[0041] according to Figures 1 to 2 As shown, the difference between this embodiment and embodiment 1 is that the left filter plate 9 and the right filter plate 10 form an angle of 30°-70° with the horizontal plane.

[0042] Compared with embodiment 1, this embodiment further defines the left filter plate 9 and the right filter plate 10 .

[0043] Example 6:

[0044] according to Figures 1 to 2 As shown, the difference between this embodiment and embodiment 1 is that the calcium injection port 2 is connected to a calcium injection conduit 12, one end of the calcium injection conduit 12 is connected to a calcium injection nozzle 13 in the gasification furnace 1, and the calcium injection conduit 12 is connected to the second dechlorination agent bin through a second blower.

[0045] Compared with Example 1, this embodiment further defines the calcium injection port 2 , and the dechlorination agent in the second dechlorination agent bin is sprayed into the gasifier 1 through the calcium injection conduit 12 by the second blower, thereby causing a dechlorination reaction on the domestic waste in the gasifier 1 .

[0046] Example 7:

[0047] according to Figures 1 to 2 As shown, the difference between this embodiment and embodiment 1 is that the calcium injection conduit 12 is arranged to be tilted downward.

[0048] Compared with Example 1, this embodiment further defines the calcium spraying guide tube 12. The purpose of the downwardly inclined setting of the calcium spraying guide tube is to effectively spray the dechlorination agent onto the garbage, thereby further reducing the chlorine content in the crude gasification gas.

[0049] Example 8:

[0050] according to Figures 1 to 2 As shown, the difference between this embodiment and embodiment 1 is that the longitudinal orthographic projections of the left filter plate 9 and the right filter plate 10 do not intersect.

[0051] Compared with Example 1, this embodiment further limits the calcium injection conduit 12. The purpose of the non-intersection of the longitudinal projections of the left filter plate 9 and the right filter plate 10 is to avoid local congestion of the crude gas between the left filter plate 9 and the right filter plate 10, thereby affecting the filtering effect.

Claims

1. A composite dechlorination system for treating domestic waste by gasification, comprising a gasifier and a composite dechlorination system, characterized in that: The composite dechlorination system includes a chlorine coarse filtration device and a cyclone separator dechlorination device. The chlorine coarse filtration device includes a plurality of filter plates arranged from top to bottom in the gasifier and a calcium injection port provided on the gasifier. One end of the filter plate is connected to the gasifier. The filter plate is tilted downward from the fixed end to the free end, so that when the calcium-based dechlorinator continuously rises with the crude gasification gas and encounters the filter plate tilted downward from the fixed end to the free end, the fixed particles and the calcium-based dechlorinator in the rising crude gasification gas are precipitated and roughly removed, thereby preventing the solid particles and the calcium-based dechlorinator in the crude gasification gas from continuing to rise. The precipitated calcium-based dechlorinator refluxes to the gasification reaction layer after precipitation, forming secondary dechlorination in the furnace. The gasifier includes a gasification reaction layer and a filter layer for placing the chlorine coarse filtration device. The filter layer is provided at the top of the gasification reaction layer, and the calcium injection port is provided at the gasification reaction layer. The filter plates include a left filter plate provided on the left side of the gasifier and a right filter plate provided on the right side of the gasifier. The left filter plate and the right filter plate are staggered from top to bottom in the gasifier to form an arched baffle area. The upper and lower adjacent left filter plates and the right filter plates form a single filtration cycle. The gasifier is provided with a plurality of filtration cycles. The longitudinal orthographic projections of the left filter plate and the right filter plate do not intersect, so as to avoid local congestion of the crude gas between the left filter plate and the right filter plate, thereby affecting the filtering effect; The cyclone separator dechlorination device includes a cyclone separator connected to the gas outlet of the gasifier, and a plurality of dechlorination agent nozzles are provided on the top of the cyclone separator, and the dechlorination agent nozzles are connected to the first dechlorination agent bin through a first blower; The filter plate is a flat filter plate, which is rotatably connected to the gasifier via a rotating device. The rotating device includes a rotating shaft connected to the filter plate and a rotating motor, and the rotating motor is connected to the rotating shaft.

2. A composite dechlorination domestic waste gasification treatment system according to claim 1, characterized in that: The left filter plate and the right filter plate form an angle of 30°-70° with the horizontal plane.

3. A composite dechlorination domestic waste gasification treatment system according to claim 1 or 2, characterized in that: The calcium spray port is connected to a calcium spray conduit, one end of which is connected to a calcium spray nozzle in the gasifier, and the calcium spray conduit is connected to a second dechlorination agent bin through a second blower.

4. A composite dechlorination domestic waste gasification treatment system according to claim 3, characterized in that: The calcium spraying conduit is arranged to be tilted downward.

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