Plasma-assisted multi-mode pyrolysis gasification furnace and plasma multi-mode organic solid waste pyrolysis gasification device

Abstract

The invention provides a plasma-assisted multi-mode pyrolysis gasification furnace and a plasma multi-mode organic solid waste pyrolysis gasification device. The plasma-assisted multi-mode pyrolysis gasification furnace comprises a shell, a furnace chamber in the shell, a feeding port located in the upper portion of the shell, a discharging port located in the lower side of the shell, a slag outlet located in the lower portion of the shell, an air inlet located in one side of the shell and an emergency chimney located on the upper portion of the shell, and a first fire grate and a second fire grate are arranged in the furnace chamber; the drying area and the pyrolysis area are distinguished; the first fire grate is arranged on the upper portion of the furnace chamber so as to form a drying area above the furnace chamber, and the second fire grate is arranged on the lower portion of the furnace chamber so as to form a pyrolysis area below the furnace chamber.

Description

Technical Field

[0001] The present invention relates to the technical field of organic solid waste treatment, and particularly to a plasma-assisted multi-modal pyrolysis gasification furnace and a plasma multi-mode pyrolysis gasification organic solid waste device. Background Art

[0002] Solid waste treatment is a major environmental protection issue today. So far, solid waste treatment needs to be disposed of separately according to the different compositions of the waste, resulting in a huge waste of social costs. For example, biomass waste, domestic waste, hazardous waste and medical waste, and organic-inorganic mixed industrial solid waste all require separate waste treatment devices, and more commonly, different waste treatment plants need to be built for disposal.

[0003] At present, for domestic waste treatment, the mainstream grate fire combustion technology is relatively mature. However, because it is aerobic combustion, a large amount of air needs to be injected. In order to avoid air pollution, a large-scale and costly flue gas treatment device needs to be built. Therefore, there is no mature treatment technology for small-scale (daily treatment volume less than 300 tons) domestic waste treatment. The investment cost per unit weight of waste disposal is high, and the operating cost is high, which is a difficult problem in the industry. Further, the grate fire combustion pyrolyzes organic solid waste into carbon dioxide, greatly increasing carbon emissions.

[0004] For the disposal of organic-inorganic mixed industrial solid waste, traditionally it enters the cement kiln for combustion disposal. However, with the improvement of environmental protection requirements, the state has begun to restrict the types and total amounts of industrial solid waste entering the cement kiln. The latest attempt is to build a converter fire combustion, which not only has a high investment cost, but also has high combustion energy consumption and costs. More seriously, the slag produced cannot be treated. For the disposal of medical waste and hazardous waste, it is necessary to reach and maintain a high temperature of 1100°. At present, the main method is to use the industrial converter (aerobic open fire combustion) technology for disposal, with large investment and high operating costs, which is very uneconomical. Or mixing medical waste and hazardous waste into the cement kiln for combustion disposal also has many disadvantages. Summary of the Invention

[0006] The present invention aims to achieve a pyrolysis gasification device that operates at a constant temperature with multiple pyrolysis temperatures (multi-modal) under plasma assistance, so as to solve all the above-mentioned organic solid waste disposal problems with one furnace body.

[0007] The present invention provides a plasma-assisted multi-modal pyrolysis gasification furnace. The plasma-assisted multi-modal pyrolysis gasification furnace includes a housing, a furnace cavity inside the housing, a feed inlet located above the housing, a discharge outlet located on the lower side of the housing, a slag discharge outlet located below the housing, an air inlet located on one side of the housing, and an emergency chimney located above the housing.

[0008] Wherein, the furnace cavity includes a first grate and a second grate to distinguish the drying zone and the pyrolysis zone.

[0009] Among them, the first grate is arranged at the upper part of the furnace cavity to form a drying area above the furnace cavity. The first grate is configured to receive the organic solid waste to be processed, dry the received organic solid waste according to the set drying time, and be controlled by the control system to discharge the organic solid waste on the first grate to the pyrolysis area after drying according to the set time. Among them, the drying time is set according to the water content of the organic solid waste;

[0010] Among them, the second grate is arranged at the lower part of the furnace cavity to form a pyrolysis area below the furnace cavity. The second grate is configured to receive the dried organic solid waste, and carry out a pyrolysis reaction on the dried organic solid waste by heating the dried organic solid waste and the gasifying agent, and discharge the slag after pyrolysis through the slag outlet, and send out the syngas generated after pyrolysis through the discharge port;

[0011] Among them, a plasma gun and the air inlet are connected above the pyrolysis area to send plasma and the gasifying agent for pyrolysis into the pyrolysis area respectively. The plasma gun provides plasma according to the temperature in the furnace cavity and the set conditions. The pyrolysis area is configured such that when the organic solid waste falls above the second grate, there is a gap sufficient for the plasma reaction between the top of the organic solid waste and the first grate.

[0012] In one aspect, the first grate is a multi-piece mesh structure, and the first grate discharges the organic solid waste by vibration.

[0013] In one aspect, the set time is configured as the time required for the water content of the organic solid waste to reach 20% or be lower than 20%.

[0014] In one aspect, the plasma-assisted multimodal pyrolysis gasifier further includes a slag area and a convex grate. The slag enters below the second grate and enters the slag area and the convex grate through the slag outlet to allow the slag to leak out.

[0015] In one aspect, the plasma gun includes a cathode in the middle and an anode arranged around the cathode. A working gas is fed between the cathode and the anode to cause the working gas to generate charges under the action of an electric arc to form plasma.

[0016] In one aspect, the plasma-assisted multimodal pyrolysis gasifier further includes a blower. The blower feeds the gasifying agent through the air inlet to provide the gasifying agent required for the pyrolysis of the dried organic solid waste above the second grate, and sends the heat radiation upward above the first grate to help dry the organic solid waste.

[0017] In one aspect, the pyrolysis zone is arranged such that after the organic solid waste falls from the first grate to the second grate, there is a distance between the dried organic solid waste falling on the second grate and the first grate to form an oxidation cavity, so as to avoid blocking the jet of the plasma gun, and the distance is 10%-20% of the height of the furnace cavity.

[0018] In one aspect, it further includes a bed height pressure sensor, and the bed height pressure sensor is located on the inner wall of the cavity above the pyrolysis zone to measure the height of the organic solid waste on the second grate and transmit the measured height to the bed height controller to judge whether the measured height is sufficient for the jet of the plasma gun.

[0019] In one aspect, it further includes a temperature sensor and a plasma controller to control the flow rate and frequency of the emitted plasma according to the temperature measured by the temperature sensor, so that the excess air coefficient in the furnace cavity is maintained between 0.1 and 0.3.

[0020] The present invention also provides a plasma multi-mode pyrolysis gasification device for organic solid waste, and the plasma multi-mode pyrolysis gasification device for organic solid waste includes the plasma-assisted multi-modal pyrolysis gasification furnace according to the foregoing, a plasma auxiliary secondary combustion chamber communicated with the plasma-assisted multi-modal pyrolysis gasification furnace, and a waste heat boiler system communicated with the plasma auxiliary secondary combustion chamber.

[0021] Wherein, the plasma auxiliary secondary combustion chamber includes a housing, a secondary combustion chamber air inlet on one side of the housing, a secondary combustion chamber air outlet on the other side of the housing, a secondary air inlet, and a second plasma gun. By receiving the combustion-supporting gas from the secondary air inlet and the plasma sent by the plasma gun, the syngas from the plasma-assisted multi-modal pyrolysis gasification furnace is burned, and the discharged high-temperature flue gas is sent to the waste heat boiler system.

[0022] The present invention provides a "one furnace, multiple pyrolysis" solution, that is, by using one furnace body, targeted temperature settings can be made according to the different temperatures required for different garbage disposals, and constant temperature of the set temperature can be achieved, and one furnace body meets the needs of the above-mentioned multiple garbage disposals.

[0023] The present invention itself adopts the way of oxygen-deficient combustion, and naturally has the characteristic of reducing atmospheric emissions compared with open fire combustion with oxygen. On this basis, the present invention makes full use of the self-ignition of the calorific value contained in the garbage to further reduce the energy consumption of garbage disposal.

[0024] Generally speaking, the present invention is a multi-modal pyrolysis gasification furnace technology assisted by plasma instant heating. "Multi-modal" refers to the temperatures of 650° required for biomass waste disposal, 850° required for domestic waste disposal, 1100° required for hazardous waste and medical waste disposal, and higher temperatures up to 2000° required for organic-inorganic mixed solid waste disposal. Plasma assistance mainly refers to furnace ignition and heat compensation when the temperature is lower than the set temperature, so as to achieve an instant ignition and instant heat compensation constant temperature combustion state. Carbon monoxide, methane and hydrogen are obtained through the gasification of organic solid waste and recycled as combustible resources.

[0025] In the high-temperature section mode (generally above 1300°), the pyrolysis furnace of the present invention can also dispose of organic and inorganic mixed industrial solid waste, gasify inorganic anions, and the residual heavy metals and silicon form a glassy substance to achieve heavy metal vitrification sealing layer, which is the most environmentally friendly disposal method for hazardous waste.

[0026] Generally speaking, first, the solid waste to be disposed is utilized to achieve self-ignition, thereby reducing the combustion energy consumption. When the calorific value of the solid waste is not enough to reach the disposal temperature required by the national standard, a plasma gun that can provide a temperature of tens of thousands of degrees is used for heat compensation. Plasma has the characteristics of instant start and stop, and a constant temperature of the required disposal temperature is achieved through the heat source provided by self-ignition and plasma. For organic-inorganic mixed industrial solid waste, according to the organic matter content and material composition of the object to be disposed, siliceous materials (such as broken glass, sand) can be appropriately mixed to seal the environmental pollutants that cannot be gasified in the siliceous glass particles.

[0027] In summary, the present invention is used to treat organic solid waste. First, a miniaturized design is adopted to effectively solve the problems of large collection radius of organic solid waste, difficult transportation and existing risks. Second, plasma is used to supplement heat during the pyrolysis gasification process of organic solid waste to effectively solve the problem of unstable pyrolysis gasification conditions after miniaturization. Compared with the existing plasma pyrolysis gasification technology, the energy consumption is greatly reduced and the cost is saved. Third, the pyrolysis gasification organic solid waste device of the present invention has been optimized in structure to realize the intermittent heat compensation of the plasma gun, the self-heating pyrolysis gasification of organic solid waste, make full use of the heat of organic solid waste itself, and output stable synthesis gas. Fourth, to solve the problems of many types of organic solid waste and great treatment difficulty, the present invention can perform mode-based treatment for different types of organic solid waste. Fifth, the present invention adopts a double-layer grate structure for plasma intermediate heat compensation design, which solves the limitation that the plasma outlet can only be set in the upper free space, can perform faster and less heat compensation, and is more rapid and energy-saving. Using the equipment and method of the present invention, the pyrolysis and treatment of organic solid waste can be integrated, the problems of medium and small-sized organic solid waste disposal can be solved, the problems of investment recovery and benefits of organic solid waste disposal can be solved, and the problems of land occupation, high investment and high treatment cost of organic solid waste treatment can be solved. Description of the Drawings

[0028] Preferred forms of embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0029] Figure 1A and 1B shows a schematic diagram of a plasma multi-mode pyrolysis gasification organic solid waste device and a plasma gun according to a preferred embodiment of the present invention;

[0030] Figure 2 shows a schematic diagram of a plasma multi-mode pyrolysis gasification organic solid waste device according to a preferred embodiment of the present invention;

[0031] Figure 3A and 3B shows a graph of gasification efficiency, gas production flow rate, and gas production heat of an example according to a preferred embodiment of the present invention. Detailed Embodiment

[0032] The preferred embodiment of the present invention proposes an organic solid waste treatment device. By adopting the method of the present application, organic solid waste can be fully treated.

[0033] Figure 1A shows a plasma multi-mode pyrolysis gasification organic solid waste device according to a preferred embodiment of the present invention, Figure 2 shows a schematic representation of a plasma multi-mode pyrolysis gasification organic solid waste device according to a preferred embodiment of the present invention. As Figure 1AAs shown, the plasma-assisted multimodal pyrolysis gasification furnace 12 of the plasma multimode pyrolysis gasification organic solid waste device includes a housing, a feed inlet 201 located above the housing, a gas outlet 124 located on one side of the housing, a slag outlet 122 located below the housing, an air inlet 126 located on one side of the housing, and an emergency chimney (not shown) located above the housing. Two layers of grates 203 are provided inside the housing, namely the first grate and the second grate, which respectively distinguish the areas for gradually drying and pyrolyzing the incoming organic solid waste to be treated, so as to finally generate combustible syngas and slag. In one example, the inner diameter of the furnace body of the plasma-assisted multimodal pyrolysis gasification furnace 12 is 800 - 1200 mm, such as 850 - 1150 mm, 900 - 1100 mm, 950 - 1050 mm, 1000 mm, etc., and the height of the furnace body is 2500 - 5000 mm, such as 3000 - 4500 mm, 3500 mm, 4000 mm, etc., not limited to the above. Thus, the capacity to treat organic solid waste can be 500 kg / h. Among them, according to needs, the diameter of the first grate can be set to be slightly smaller than the inner diameter of the furnace body, and the diameter of the first grate is 790 - 1190 mm, such as 840 - 1140 mm, 890 - 1090 mm, 940 - 1040 mm, 990 mm, etc. The second grate can be a suitable grate, such as a tower grate, and its diameter is 500 - 700 mm, such as 550 mm, 600 mm, 650 mm, etc. Thus, a miniaturized furnace body is achieved, which is suitable for various locations where organic solid waste needs to be treated.

[0034] The inner furnace body of the plasma-assisted multi-modal pyrolysis gasifier is specifically arranged from top to bottom as a furnace chamber, a drying zone, a first grate, a pyrolysis zone, an oxidation zone, a reduction zone, a second grate, an ash zone, and a convex grate. These zones can be partially overlapped or arranged in sequence. Above the feed inlet is a funnel part to increase the area for receiving organic solid waste. The outer shell of the plasma-assisted multi-modal pyrolysis gasifier includes a furnace cover, and on the furnace cover there is a feeding machine, such as a double-roll continuous feeding machine, to uniformly add the organic solid waste to be treated into the furnace chamber. The feed inlet can include a rotatable mechanism to scatter the organic solid waste into the furnace chamber. The organic solid waste entering the furnace chamber passes through the drying zone for drying. In the drying zone, the organic solid waste is dried by high temperature to evaporate its moisture, becoming dry organic solid waste and making it easy to undergo pyrolysis. The organic solid waste falling into the drying zone is blocked by the first grate to ensure the duration required for the drying process. The duration of the drying process is controlled by the control system to discharge the organic solid waste on the first grate into the pyrolysis zone after drying according to the set time, where the drying time is set according to the water content of the organic solid waste. The set time is configured to be the time required for the water content of the organic solid waste to reach 20% or be lower than 20%. In one example, when the water content of the organic solid waste is higher than 40%, the control system automatically extends the residence time of the organic solid waste in this area according to the water content in the organic solid waste, so as to dry the water content to below 20% and send it to the pyrolysis zone through the operation of the first grate.

[0035] The dried organic solid waste falls into the pyrolysis zone through the vibration of the first grate. The drying time of the organic solid waste can be predetermined. Generally, for different organic solid wastes, the time is slightly different. In the control system, the default values of the drying time are set as follows: for medical organic solid waste, it is set to 12 - 18 minutes, such as 13 minutes, 14 minutes, 15 minutes, 16 minutes, 17 minutes, etc.; for domestic organic solid waste, it is set to 4 - 10 minutes, such as 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, etc.; for chemical organic solid waste, it is set to 8 - 15 minutes, such as 9 minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, etc.; for biomass solid waste, it is set to 5 - 10 minutes, such as 6 minutes, 7 minutes, 8 minutes, 9 minutes, etc. The drying time setting can be set by itself in the manufacturer's parameters according to the actual operation situation. In addition, for organic solid wastes with different water contents, the drying time can also be appropriately extended or shortened, such as extended or shortened by 1 - 3 minutes.

[0036] The dried organic solid waste falls into the pyrolysis zone for pyrolysis treatment. First, the air inlet 126 is located above the pyrolysis zone and communicates with the outside, so as to send external air into the pyrolysis zone. The plasma gun 202 is also arranged to communicate with the upper part of the pyrolysis zone, so as to send plasma into the inner furnace body of the plasma-assisted multi-modal pyrolysis gasification furnace. The plasma gun can be, for example Figure 1B As shown, it includes a cathode in the middle, an anode arranged around the cathode, and a working gas, such as air, is sent between the cathode and the anode, so that the working gas generates charges under the action of the formed arc, and positive and negative ions generated by the ionization of atoms and atomic groups after partial electrons are deprived form plasma and are sent into the oxidation zone. The plasma emitted by the plasma gun helps the received air to heat up, so as to realize the pyrolysis reaction of the organic solid waste in the pyrolysis zone above the second grate. To ensure full reaction, considering the injection height of the plasma gun, enough space should be left between the top of the organic solid waste above the second grate and the first grate to enable full reaction. In one example, the space left between the top of the organic solid waste above the second grate and the first grate is greater than 10% of the furnace body height, such as 12%, 14%, 16%, 18%, 20% of the furnace body height, etc., but not exceeding 40% of the furnace body height. For example, when the furnace body height is 3500 mm, the reserved space can be greater than 500 mm, which is conducive to the full reaction of the plasma.

[0037] The organic solid waste falls from the first grate to the second grate, and an oxidation cavity 206 is formed between the organic solid waste falling on the second grate and the first grate, so that the injection height of the plasma gun is not blocked as much as possible, so that the emitted plasma can fully contact the air and maintain the temperature at a suitable temperature, such as 250°C - 700°C. Through the pyrolysis reaction, most of the volatile components in the organic solid waste are separated from the solid, and it is basically completed at 500°C - 600°C. The main products in the pyrolysis zone are ash, hydrogen, water vapor, carbon monoxide, carbon dioxide, methane, tar and other hydrocarbon substances, etc.

[0038] Optionally, a plasma controller is also provided, which controls the flow rate and frequency of the emitted plasma. For example, when there is more organic solid waste to be processed or a higher pyrolysis temperature is required, the flow rate and frequency of plasma generation and emission increase, while if there is less organic solid waste to be processed or a lower pyrolysis temperature is required, the flow rate and frequency of plasma generation and emission decrease. The heating power and heating time of the plasma gun are adjusted according to the measured value of the temperature sensor in the pyrolysis zone of the furnace body and the pyrolysis temperature threshold required for the solid waste, ensuring that the pyrolysis zone of different solid wastes always remains within the required temperature threshold range. The excess air coefficient in the furnace cavity is maintained between 0.1 and 0.3, for example, between 0.15 and 0.25, such as 0.16, 0.18, 0.2, 0.22, 0.24, etc. Thus, by controlling the plasma generation rate, air flow rate, and excess air coefficient, etc., and controlling the temperature through plasma, the problem of pyrolysis stability of small-scale organic solid waste treatment equipment can be solved.

[0039] Optionally, a bed height pressure sensor and a bed height controller are also provided. The bed height pressure sensor is located on the inner wall of the cavity above the pyrolysis zone or at a suitable position to measure the height of the organic solid waste on the second grate, so as to determine whether the height between the top of the organic solid waste and the first grate is sufficient to allow a sufficient amount of air to contact the plasma for reaction, and transmit the received data to the bed height controller. The bed height controller is used to judge and compare the received height with the preset height. If the measured bed height is greater than the preset height, it means that there is too much organic solid waste and the space reserved for the plasma reaction is too small. At this time, a warning can be generated or a part of the organic solid waste can be discharged according to the setting; if the measured bed height is less than or equal to the preset height, it means that the space reserved for the plasma reaction is sufficient for sufficient pyrolysis, and an appropriate amount of air and plasma can be continuously provided.

[0040] Optionally, the blower sends the primary air into the middle air chamber through the air inlet, and adjusts the rotation speed of the blower according to the feedback signal of the bed thickness sensor on the second grate and the pyrolysis zone temperature, so as to adjust the flow rate of the gas provided for combustion support, that is, the gasifying agent, entering the pyrolysis layer, and after generating high temperature, dry the drying zone through thermal radiation, so as to form a convection with the organic solid waste from top to bottom. When a higher temperature is required, more air and more plasma are provided to raise the temperature in the furnace cavity.

[0041] Optionally, a temperature sensor is provided to measure the temperature of the pyrolysis zone and transmit the measured temperature to a control system, which makes adjustments based on the comparison between the measured temperature and a temperature threshold. In one example, the temperature control range for organic hazardous solid waste and medical organic solid waste is set to 1000 - 1200 °C; the temperature for domestic organic solid waste is set to 800 - 1000 °C; the temperature control range for biomass organic solid waste is set to 650 - 850 °C. If the measured temperature is too high, higher than the selected value or the maximum value in the above temperature control range, the supply of air and / or plasma is reduced; if the measured temperature is too low, lower than the selected value or the minimum value in the above temperature control range, the supply of air and / or plasma is increased, so as to control the temperature inside the furnace within the temperature control range. Optionally, the temperature control range can be kept constant during the treatment process in the following way: when the temperature drops below the threshold or the threshold range, the control system controls to increase the input of plasma and gasifying agent (such as air) to increase the pyrolysis temperature; when the temperature is higher than the threshold or the threshold range, the control system reduces or keeps the input of plasma and gasifying agent (such as air) to lower the pyrolysis temperature.

[0042] During pyrolysis, heat flows upward to be provided as heat for drying to the upper drying zone.

[0043] Below the second grate, there is an ash zone and a convex furnace grate provided to allow the slag after the pyrolysis reaction to leak out.

[0044] Specifically, the organic solid waste is fed into the upper funnel of the vertical feeding bin of the plasma-assisted multimodal pyrolysis gasification furnace, and the organic solid waste in the bin is continuously, evenly and uninterruptedly fed into the plasma-assisted multimodal pyrolysis gasification furnace according to the set processing capacity through the double-roller continuous feeder installed on the furnace cover. The feeding port can rotate during feeding so that the organic solid waste fed into the plasma-assisted multimodal pyrolysis gasification furnace is scattered on any surface of the furnace cross-section along the furnace radius plane. The organic solid waste entering the furnace moves slowly from top to bottom and is first intercepted by the first grate in the drying zone to dry the organic solid waste. Among them, a plasma gun is used to provide ignition operation during ignition. In the drying zone, it is first affected by the high-temperature thermal radiation from bottom to top and rapidly heats up in the drying zone to dry and evaporate the moisture, and the generated water vapor is discharged. The greater the water content of the organic solid waste, the more heat energy is required for the drying process, resulting in a faster temperature drop in the plasma-assisted multimodal pyrolysis gasification furnace and a greater impact on the pyrolysis efficiency. At this time, a temperature sensor can be optionally used to measure the temperature in the drying zone, and the flow rate and frequency of the plasma delivery will be automatically or manually adjusted according to the measured temperature, so as to increase or decrease the reaction temperature to control the problem in the drying zone. Under the strong heat transfer of the high-temperature hot gas flow in the furnace, the organic solid waste is heated by convection and radiation, and first the moisture attached to the surface of the hazardous waste is heated and precipitated, and the rapid volatilization of the moisture completes the drying process of the hazardous waste.

[0045] After the drying process, due to the need to supply a large amount of heat, a pyrolysis zone forming a drying area is formed in the furnace. The heat for plasma drying is provided by the pyrolysis zone below. In the pyrolysis zone, the plasma gun provides plasma and the air inlet provides air. The thermal decomposition gasification process of the plasma is to break the chemical bonds of the organic matter in the organic solid waste by using the heat energy of the plasma torch under anaerobic or anoxic conditions, making it into small molecules. The reaction products include various hydrocarbons, fixed carbon and incomplete combustibles, etc. The combustible solids in the organic solid waste are generally composed of elements such as C, H, O, N, S, Cl, etc. Therefore, in the pyrolysis zone, only a small amount of oxygen is needed to reduce the treated organic solid waste into low-molecular combustible compounds. Using the plasma emitted by the plasma gun, when the temperature in the pyrolysis gasification device of the organic solid waste is in the range of 300°C - 600°C, the substances in the organic solid waste undergo plasma pyrolysis. In this stage, the inherent water in the organic solid waste is precipitated, and deoxidation and desulfurization reactions occur with the production of carbon dioxide. The macromolecules of substances such as cellulose, protein, and fat in the organic solid waste are broken down into solid-state compounds and small-molecule gases. During pyrolysis, the organic solid waste is basically decomposed into combustible gas, namely syngas, and solid residue.

[0046] During the top - down movement of organic solid waste, it is first affected by the bottom - up high - temperature hot gas flow, rapidly heats up in the drying zone for drying and evaporates moisture. Then pyrolysis occurs, and when the temperature further rises above 600 °C, a large amount of organic matter begins to decompose and gasify into combustible syngas such as CO and H2, which enter the plasma - assisted secondary combustion chamber with the rising high - temperature flue gas for pyrolysis. As the drying and pyrolysis proceed, the temperature of the organic solid waste further increases. A large amount of heat is released during the intense pyrolysis of the organic matter, and this heat can also provide the heat required for the drying, heating - up, and thermal decomposition processes of the newly introduced organic solid waste into the furnace.

[0047] During the continued downward movement of the high - temperature residue ash remaining after oxidative pyrolysis, it is cooled by the bottom - up air. The heat carried by it is absorbed by the air and pre - heats the air. The cooled residue is squeezed and crushed into lumps smaller than 150 mm under the action of the convex grate and discharged into the conical ash hopper below the air chamber, and then falls into the tower - shaped grate below through the ash hopper and is discharged by the screw feeder.

[0048] The pyrolysis mode can be set according to the organic solid waste to be treated. For example, for organic hazardous solid waste and medical organic solid waste, the pyrolysis temperature is 1000 - 1200 °C, such as 1050 °C, 1100 °C, 1150 °C; for domestic organic solid waste, the pyrolysis temperature is 800 - 1000 °C, such as 850 °C, 900 °C, 950 °C; for biomass organic solid waste, the pyrolysis temperature is 650 - 850 °C.

[0049] The plasma multi - mode pyrolysis gasification device for organic solid waste also includes a plasma - assisted secondary combustion chamber 13. The light - component gas and heavy - polycyclic aromatic hydrocarbons (tar) generated by the pyrolysis of the organic solid waste from the plasma - assisted multi - modal pyrolysis gasification furnace 12, as well as light - component gases such as carbon dioxide, carbon monoxide, hydrogen, methane, etc., enter the plasma - assisted secondary combustion chamber from below.

[0050] According to an embodiment of the present invention, the plasma - assisted secondary combustion chamber 13 has a hollow structure, including a housing, a secondary combustion chamber feed port on one side of the housing, a secondary combustion chamber discharge port on the other side of the housing, a secondary air inlet, and a secondary combustion chamber plasma gun 204. The syngas from the plasma pyrolysis gasification device for organic solid waste, such as light - component gas and heavy - polycyclic aromatic hydrocarbons, is helped to burn by the plasma emitted by the secondary combustion chamber plasma gun and clean gas is discharged. The secondary combustion chamber plasma gun can also be, for example Figure 1B as shown.

[0051] Specifically, the syngas entering the furnace of the plasma-assisted secondary combustion chamber undergoes combustion in the oxidation zone. In the oxidation zone, CO, CH4, etc. in the flue gas are completely oxidized, and oxidative combustion occurs to form gases such as carbon dioxide and then discharged. Among them, with the assistance of the plasma sent by the plasma gun 204 in the secondary combustion chamber, the combustion speed can be increased and the combustion efficiency can be improved.

[0052] All the secondary fly ash after being treated by the plasma-assisted secondary combustion chamber, including the unmolten fly ash carried by the flue gas, volatilized salts, etc., enters the waste heat boiler system 14. The waste heat boiler system includes a waste heat boiler, a heat utilization system, and a tail gas treatment system. The waste heat boiler, the heat utilization system, and the tail gas treatment system are connected by pipelines. The gas leaving the waste heat boiler system is discharged after being treated by the tail gas treatment system.

[0053] The organic solid waste treatment method according to an embodiment of the present invention includes the following steps:

[0054] S1. First, the organic solid waste to be treated is fed from the feeding device into the plasma-assisted multimodal pyrolysis gasification furnace in the plasma multimode pyrolysis gasification organic solid waste device;

[0055] S2. The organic solid waste to be treated is dried in the plasma-assisted multimodal pyrolysis gasification furnace, and the high-temperature gas heated by the plasma emitted by the plasma gun is used for drying treatment to remove the moisture in the organic solid waste;

[0056] S3. The dried organic solid waste is pyrolyzed in the plasma-assisted multimodal pyrolysis gasification furnace, and the plasma emitted by the plasma gun is used for high-temperature pyrolysis treatment to form combustible syngas and slag, and the slag is discharged;

[0057] S4. The combustible syngas is sent into the plasma-assisted secondary combustion chamber, and the combustible syngas is fully combusted with the assistance of plasma, and the flue gas obtained after combustion is discharged to the waste heat boiler. The heat in the waste heat boiler can be used for steam power generation, and the cooled flue gas is subjected to tail gas treatment.

[0058] By using the above device and method of the present invention for treatment, various solid wastes can be treated, including domestic organic solid waste, industrial organic solid waste, and medical organic solid waste. Solid wastes with a water content of up to 60% can be treated, enabling the organic solid waste to be cracked into combustible low-molecular compounds, including gaseous hydrogen, methane, carbon monoxide, etc., and solid coke, carbon black, etc. Thus, most of the organic solid waste can be recycled. The method of the present invention enables the organic matter in the organic solid waste, such as dioxin, to be completely decomposed by high-temperature plasma, and the content of toxic and harmful substances such as heavy metal ions in the formed vitrified slag is also all lower than the control limit standard for hazardous waste landfill treatment. At the same time, it can produce at least 2000 m³ of gas with a calorific value of 2000 kcal / ton 3, thus achieving more than three times the current efficiency.

[0059] Example 1

[0060] The organic solid waste treatment equipment according to an embodiment of the present invention treats organic solid waste containing the components shown in Table 1 below.

[0061] Table 1 Physical composition of garbage 1)

[0062] Table 1 Composition analysis of garbage %

[0063]

[0064] Note: 1) By mass fraction.

[0065] The effect of treating organic solid waste is as Figure 3A and Figure 3B shown. It can be seen that the gasification efficiency increases with the increase of temperature. At 850 °C, the gasification efficiency reaches 72%, the gas production flow rate can reach 12500 m3·h-1, and the heat generated per unit hour by the produced gas and the lower calorific value of the gasified gas are also higher than 12200 MJ·h-1 and 12200 kJ·m-3.

[0066] By using the method of the present invention, the pyrolysis of solid organic solid waste and the treatment of organic solid waste leachate in the disposal of organic solid waste can be integrated. First, through the PLZM multi-mode stage plasma pyrolysis furnace technology, the problems of using one furnace for multiple purposes, miniaturization of pyrolysis, mobile pyrolysis in skid-mounted form, and investment recovery and benefits in the disposal of organic solid waste are solved.

[0067] As used in this specification, the term "comprising" means "comprising at least in part". When interpreting each statement in this specification that contains the word "including", there may also be features other than or in addition to those starting with this word. Related terms such as "comprising" and "including" should be interpreted in the same way.

[0068] For those skilled in the art to which the present invention pertains, many variations in the structure of the present invention and a wide variety of different embodiments and applications of the present invention will be obvious without departing from the scope of the present invention defined by the appended claims. The disclosure and description herein are purely illustrative and are not intended to be limiting in any sense. When referring to specific integers known to have equivalents in the art related to the present invention, these known equivalents are considered to be incorporated herein as if individually set forth.

[0069] As used herein, the term "and / or" means "and" or "or" or both.

[0070] In the description of the present specification, reference may be made to subject matter that is not within the scope of the appended claims. Such subject matter should be readily recognizable to those skilled in the art and may assist in putting into practice the invention as defined in the appended claims.

[0071] Although the invention has been generally defined as above, those skilled in the art will understand that the invention is not limited thereto, and the invention also includes embodiments exemplified by the following examples.

[0072] The foregoing description of the invention includes its preferred forms. Modifications may be made thereto without departing from the scope of the invention.

Claims

1. A plasma-assisted multi-modal pyrolysis gasification furnace, characterized in that, The plasma-assisted multimodal pyrolysis gasifier includes a housing, a furnace chamber inside the housing, a feed inlet located above the housing, a discharge outlet located on the lower side of the housing, a slag discharge outlet located below the housing, an air inlet located on one side of the housing, and an emergency chimney located above the housing. Among them, the furnace chamber includes a first grate and a second grate to distinguish the drying zone and the pyrolysis zone. Among them, the first grate is arranged at the upper part of the furnace chamber to form a drying zone above the furnace chamber. The first grate is configured to receive the organic solid waste to be processed, dry the received organic solid waste according to the set drying time, and be controlled by the control system to discharge the organic solid waste on the first grate to the pyrolysis zone after drying according to the set time. Among them, the drying time is set according to the water content of the organic solid waste. Among them, the second grate is arranged at the lower part of the furnace chamber to form a pyrolysis zone below the furnace chamber. The second grate is configured to receive the dried organic solid waste, and carry out a pyrolysis reaction on the dried organic solid waste by heating the dried organic solid waste and the gasifying agent, and discharge the slag after pyrolysis through the slag discharge outlet, and send out the syngas generated after pyrolysis through the discharge outlet. Among them, a plasma gun and the air inlet are connected above the pyrolysis zone to send plasma and the gasifying agent for pyrolysis into the pyrolysis zone respectively. The plasma gun provides plasma according to the temperature in the furnace chamber and the set conditions. The pyrolysis zone is configured to have a sufficient interval for the plasma reaction between the top of the organic solid waste and the first grate when the organic solid waste falls above the second grate.

2. The plasma-assisted multimodal pyrolysis gasification furnace according to claim 1, characterized in that The first grate is a multi-piece mesh structure, and the first grate discharges the organic solid waste by vibration.

3. The plasma-assisted multimodal pyrolysis gasification furnace according to claim 1, characterized in that, The set time is configured as the time required for the water content of the organic solid waste to reach 20% or be lower than 20%.

4. The plasma-assisted multi-modal pyrolysis gasification furnace according to claim 1 or 2, characterized in that, The plasma-assisted multimodal pyrolysis gasifier further includes a slag zone and a convex grate. The slag enters below the second grate and enters the slag zone and the convex grate through the slag discharge outlet to make the slag leak out.

5. The plasma-assisted multimodal pyrolysis gasification furnace according to claim 1 or 2, characterized in that, The plasma gun includes a cathode in the middle and an anode arranged around the cathode. A working gas is sent between the cathode and the anode to make the working gas generate charges under the action of an electric arc to form plasma.

6. The plasma-assisted multimodal pyrolysis gasification furnace according to claim 1 or 2, characterized in that, The plasma-assisted multimodal pyrolysis gasifier further includes a blower. The blower sends the gasifying agent through the air inlet to provide the gasifying agent required for the pyrolysis of the dried organic solid waste above the second grate, and sends the heat radiation upward above the first grate to help dry the organic solid waste.

7. The plasma-assisted multi-modal pyrolysis gasification furnace according to claim 1 or 2, characterized in that, The pyrolysis zone is set such that after the organic solid waste falls from the first grate to the second grate, there is a distance between the dried organic solid waste falling on the second grate and the first grate to form an oxidation cavity to avoid blocking the injection of the plasma gun. The distance is 10%-20% of the height of the furnace chamber.

8. The plasma-assisted multimodal pyrolysis gasification furnace according to claim 7, characterized in that, It further includes a bed height pressure sensor. The bed height pressure sensor is located on the inner wall of the cavity above the pyrolysis zone to measure the height of the organic solid waste on the second grate and transmit the measured height to the bed height controller to judge whether the measured height is sufficient for the injection of the plasma gun.

9. The plasma-assisted multimodal pyrolysis gasification furnace according to claim 7, wherein It also includes a temperature sensor and a plasma controller to control the flow rate and frequency of the emitted plasma according to the temperature measured by the temperature sensor, so that the excess air coefficient in the furnace cavity is maintained between 0.1 and 0.

3.

10. A plasma multi-mode pyrolysis gasification organic solid waste device, characterized in that, The plasma multi-mode pyrolysis gasification organic solid waste device includes a plasma-assisted multi-modal pyrolysis gasification furnace according to any one of claims 1-9, a plasma-assisted secondary combustion chamber communicated with the plasma-assisted multi-modal pyrolysis gasification furnace, and a waste heat boiler system communicated with the plasma-assisted secondary combustion chamber. Among them, the plasma-assisted secondary combustion chamber includes a housing, a secondary combustion chamber air inlet on one side of the housing, a secondary combustion chamber air outlet on the other side of the housing, a secondary air inlet, and a second plasma gun. By receiving the combustion-supporting gas from the secondary air inlet and the plasma sent by the plasma gun, the syngas from the plasma-assisted multi-modal pyrolysis gasification furnace is burned, and the discharged high-temperature flue gas is sent to the waste heat boiler system.

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