Small-sized household garbage pyrolysis gasification incinerator and pyrolysis gasification method

Abstract

The present application provides a small household garbage pyrolysis gasification incinerator, comprising: a furnace body, a grate, a smoke collecting pipe, a pyrolysis gas output pipe, a secondary combustion chamber and a slag collecting hopper. The present application also provides a pyrolysis gasification method of the small household garbage pyrolysis gasification incinerator. The small household garbage pyrolysis gasification incinerator and the pyrolysis gasification method thereof can make the household garbage in the furnace better have a continuous pyrolysis reaction, and the required external input energy in the pyrolysis reaction process is less, the fluctuation of the hearth reaction state is smaller, the pyrolysis gas composition and temperature are more stable, and the ash ignition loss is lower, thereby being beneficial to improving the operation efficiency of the incinerator, being more beneficial to the stable operation of the secondary combustion chamber, reducing the load impact of the downstream flue gas treatment system, and reducing the comprehensive operation cost.

Description

Technical Field

[0001] This invention relates to the field of municipal solid waste treatment technology, and in particular to a small-scale municipal solid waste pyrolysis gasification incinerator and pyrolysis gasification method. Background Technology

[0002] Compared to other methods of municipal solid waste treatment, incineration has significant advantages, including rapid volume reduction, thorough harmlessness, low total pollution emissions, high resource utilization, and low environmental risk. It is the mainstream development direction for municipal solid waste treatment both domestically and internationally. There are two main models for municipal solid waste incineration: one is a large-scale centralized model using large-scale incineration systems for power generation; the other is a decentralized incineration model tailored to the distribution characteristics of municipal solid waste. Both methods have their advantages.

[0003] Compared to large-scale incineration systems, small-scale incineration systems have several distinct characteristics. These include limited furnace heat melting, operation only one or two shifts per day without continuous operation, no composting of the waste to be processed, higher moisture content and lower calorific value due to pretreatment processes such as crushing, homogenization, and magnetic separation, and a more uneven waste layer after entering the furnace. These characteristics result in lower flue gas temperatures, the generation of large amounts of harmful pollutants, and significant fluctuations in furnace temperature, flue gas composition, and temperature. This not only places a huge load on downstream flue gas treatment systems but also leads to excessive levels of pollutants, especially carbon monoxide and dioxins, during flue gas emissions.

[0004] To address the emissions issues of small-scale municipal solid waste incineration systems, pyrolysis gasification incinerators have gained attention and importance. The basic idea is to first heat the municipal solid waste in the furnace, promoting a pyrolysis reaction to generate pyrolysis gas containing combustible components, i.e., harmful pollutants in an environmental sense. This pyrolysis gas is then fed into a secondary combustion chamber supplemented with fresh air. In the secondary combustion chamber, the combustible components in the pyrolysis gas undergo oxidation, releasing heat. On one hand, the harmful pollutants are oxidized and decomposed, resulting in a lower concentration of harmful pollutants in the flue gas exiting the secondary combustion chamber. On the other hand, the higher temperature of the flue gas exiting the secondary combustion chamber further promotes the decomposition of harmful pollutants. Therefore, the greatest advantage of this type of pyrolysis gasification incinerator is the lower concentration of carbon monoxide and dioxins in the exhaust gas, resulting in better environmental performance.

[0005] However, the following three conditions must be met for this type of pyrolysis gasification incinerator to operate stably:

[0006] Condition 1: The temperature of the waste must be within the temperature range where a pyrolysis reaction can occur;

[0007] Condition 2: Since pyrolysis is an endothermic reaction, sufficient energy must be continuously provided to sustain the pyrolysis reaction when waste undergoes pyrolysis.

[0008] Condition three: The pyrolysis reaction must be carried out in a well-sealed, oxygen-free environment. Otherwise, when the waste is heated and comes into contact with oxygen, it will undergo an oxidation reaction instead of pyrolysis. The products of oxidation are non-flammable substances such as carbon dioxide and water.

[0009] To satisfy conditions one and two above, auxiliary energy must be input into the furnace to maintain the energy balance of the waste pyrolysis reaction process; to satisfy condition three above, either the waste must be placed in a specially sealed reactor, or the furnace's sealing design must be significantly strengthened to prevent external air from entering and interfering with the pyrolysis reaction. Even if the above three necessary conditions are met, the following practical engineering problems will still exist:

[0010] 1) The auxiliary energy input to the furnace from the outside either converts electrical energy into heat energy or generates heat energy by burning fossil fuels through a burner. Both of these energy input methods will result in high operating costs that are difficult to bear, especially when the moisture content of the waste is very high, which requires more external energy input and results in higher operating costs.

[0011] 2) The manufacturing cost of the equipment has increased, and the reliability and stability of the system operation are insufficient;

[0012] 3) The pyrolysis reaction of waste can only be carried out in a batch manner, that is, the next batch of waste can only be put in after the previous batch of waste has completed the pyrolysis reaction. Therefore, the overall processing speed of waste is very slow, and the processing capacity of a single furnace is generally difficult to exceed 2 tons / day.

[0013] 4) Since the operation of the pyrolysis furnace is batch-type, the composition and temperature of the pyrolysis gas are constantly fluctuating and sometimes absent, causing the secondary combustion chamber to operate unstablely and requiring repeated ignition. This not only increases operating costs but also puts a huge load on the downstream flue gas treatment system.

[0014] 5) The workload and difficulty for operators have increased significantly, making it difficult to achieve "button-operated" or automated operation;

[0015] 6) The residue after the pyrolysis of waste does not have enough oxidation reaction steps, resulting in a high carbon content in the ash residue. In addition, organic nuclei with incomplete reaction are formed in high-moisture parts such as fruits, making it difficult to meet the heat loss on ignition rate of the ash residue.

[0016] Based on the above problems, researching a small-scale municipal solid waste pyrolysis gasification incinerator that can stably and continuously carry out pyrolysis reactions in the furnace, has stable physical properties of pyrolysis gas, requires low auxiliary energy, meets the required ash and slag heat loss on ignition rate, and can also reduce the workload and difficulty of operation for operators is of great significance to the development of decentralized municipal solid waste incineration treatment mode. Summary of the Invention

[0017] The technical problem to be solved by the present invention is to provide a small-scale municipal solid waste pyrolysis gasification incinerator and a pyrolysis gasification method, which solves the problems of existing waste pyrolysis gasification incinerators that cannot achieve stable and continuous pyrolysis reaction of waste in the furnace, poor physical property stability of pyrolysis gas, large auxiliary energy, unsatisfactory ash loss on ignition rate, and high workload and difficulty for operators.

[0018] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0019] A small-scale municipal solid waste pyrolysis gasification incinerator includes:

[0020] The furnace body has an internal cavity and a feed inlet and a feed gate that can be sealed together with the feed inlet at the top.

[0021] A grate is located inside the furnace body and divides the furnace body cavity into an upper furnace chamber and a lower ash chamber; an air distribution system is provided at the grate.

[0022] A smoke collection pipe is provided on the inner side wall of the furnace body and communicates with the furnace chamber through a gas gathering channel;

[0023] A pyrolysis gas output pipe is provided on the outer side wall of the furnace body and is connected to the smoke collection pipe;

[0024] A secondary combustion chamber, wherein the inlet of the secondary combustion chamber is connected to the pyrolysis gas output pipe, and the outlet is provided with a flue gas pipe;

[0025] The slag collection hopper is located at the bottom of the furnace body and is provided with a slag discharge port and a slag discharge door that can be sealed and fitted with the slag discharge port.

[0026] Preferably, a feed gate drive mechanism is provided between the feed gate and the top of the furnace body; and / or, a slag discharge gate drive mechanism is provided between the slag discharge gate and the slag collection hopper.

[0027] Preferably, a pyrolysis temperature sensor is provided on the pyrolysis gas output pipe; and / or, a secondary combustion temperature sensor is provided on the flue gas pipe. Based on the data from the pyrolysis temperature sensor, the rate of chemical reaction of the waste in the furnace can be determined, thus providing a basis for decision-making to improve the energy balance in the furnace. Based on the data from the secondary combustion temperature sensor, combined with the data from the pyrolysis temperature sensor, the calorific value of the combustible gas components in the pyrolysis gas can be determined, thereby determining the chemical reaction state of the waste in the furnace, thus providing a basis for decision-making to optimize the reaction process within the furnace.

[0028] Preferably, the geometric center of the feed inlet coincides with the geometric center of the top of the furnace body. This arrangement improves the symmetry of the waste layer after it enters the furnace along the furnace centerline, preventing the waste layer from converging on one side of the furnace body and causing flow problems in the furnace that would be detrimental to various reactions.

[0029] Preferably, the sidewall of the furnace body is provided with an outer shell, an insulation layer, and a refractory layer from the outside to the inside. This three-layer structure not only increases the durability of the furnace body, but also reduces the heat dissipation of the furnace body, increases the strength of the furnace body, and lowers the temperature of the outer wall of the furnace body, thus reducing the possibility of burns to operators and improving safety.

[0030] Preferably, a tie rod is provided between the refractory layer and the outer shell, with one end of the tie rod fixed to the outer shell and the other end embedded in the refractory layer. The tie rod effectively prevents the refractory layer from detaching, making the furnace body's refractory layer more robust.

[0031] Preferably, the end of the anchor embedded in the fire-resistant layer is "L"-shaped or "T"-shaped.

[0032] Preferably, the ash collection hopper is equipped with ash-blocking bars inside. Each time ash is discharged, due to the blocking effect of the ash-blocking bars, some residual ash remains in the ash chamber. The retained cold ash can separate the subsequently falling hot ash from the inner wall of the ash collection hopper, or reduce the possibility of hot ash contacting the inner wall of the ash collection hopper. Since ash is a poor conductor of heat, it can reduce the surface temperature of the outer wall of the ash collection hopper, improve the operational safety of the incinerator, reduce the heat dissipation of the ash, and make it more conducive to the ideal reaction of waste in the furnace.

[0033] Preferably, the waste layer in the furnace includes, from top to bottom, a preheating and drying zone with an oxygen-free atmosphere, a pyrolysis and gasification zone with an oxygen-free atmosphere, a deep combustion zone with an oxygen-deficient atmosphere, and a burnout zone with an oxygen-rich atmosphere, and the material in the waste layer moves from top to bottom in the furnace.

[0034] The working process of the small-scale municipal solid waste pyrolysis gasification incinerator described in this invention is as follows:

[0035] The feed gate is opened by the feed gate drive mechanism, allowing the waste to be processed to enter the furnace from the feed inlet in one go. Then the feed gate is closed to prevent outside air from entering the furnace. The combustion air enters the furnace through the air distribution system to maintain the series of reactions of the waste in the furnace. After a series of reactions such as preheating, drying, pyrolysis, deep burning, and burnout in the furnace, the waste forms ash and pyrolysis gas containing organic combustible components. The ash falls into the ash chamber from the gaps in the grate.

[0036] The pyrolysis gas enters the flue gas collecting pipe from the gas gathering channel, and then enters the secondary combustion chamber through the pyrolysis gas output pipe. The pyrolysis gas mixes with the secondary combustion air that enters the secondary combustion chamber simultaneously, forming an oxygen-rich atmosphere in the secondary combustion chamber. The combustible components in the atmosphere undergo an oxidation reaction, eliminating the combustible components in the flue gas, i.e., organic pollutants, while releasing heat. This converts the pyrolysis gas into high-temperature flue gas with a higher temperature and a very low concentration of organic pollutants, which is then discharged through a high-temperature flue gas pipe or discharged downstream. The temperature of the high-temperature flue gas is 850℃-930℃.

[0037] The pyrolysis gasification method of the small-scale municipal solid waste pyrolysis gasification incinerator of the present invention is implemented using the aforementioned small-scale municipal solid waste pyrolysis gasification incinerator, and includes the following steps: the waste moves from top to bottom in the furnace and forms from top to bottom an anaerobic preheating and drying zone, an anaerobic pyrolysis gasification zone, an oxygen-deficient deep combustion zone, and an oxygen-rich combustion zone in the furnace.

[0038] When the waste enters the furnace, it first enters the preheating and drying zone in the upper part of the furnace, which is an oxygen-free atmosphere (here, "oxygen-free" refers to an extremely oxygen-deficient state with almost no oxygen). The waste is preheated and dried in the preheating and drying zone. During the preheating and drying process, the waste gradually moves towards the pyrolysis and gasification zone in the oxygen-free atmosphere and further absorbs heat to raise the temperature to above 110°C, causing the moisture in the waste to evaporate further and some organic polymer components to approach the decomposition state.

[0039] Then, the waste enters the pyrolysis gasification zone, where it further absorbs heat and heats up to the temperature range where the pyrolysis reaction can occur, initiating the pyrolysis reaction. The pyrolysis reaction includes the cracking reaction of the organic polymer components in the waste and the dry distillation reaction of the biomass components. Specifically, the organic polymer components in the waste, such as various plastics and rubbers, undergo cracking reactions when heated in an anaerobic atmosphere, generating combustible gases such as C2H4, C2H6, CH4, and H2, as well as carbon black—the so-called gasification reaction. The composition of the products varies at different temperatures; the higher the cracking temperature, the smaller the product molecules. The cracking reaction generally takes place in the temperature range of 280℃-650℃. Simultaneously, the biomass components in the waste, such as leaves and wood, undergo dry distillation reactions in an anaerobic atmosphere, generating gaseous wood tar in the furnace, wood gas containing combustible components such as CH4, H2, and CH3OH, and solid carbon—the so-called carbonization reaction. Carbonization reactions typically occur within a temperature range of 250℃-600℃, similar to the principle of common wood charcoal production. The aforementioned reactions are highly complex, with various reactions intertwined and lacking clear temperature, time, or physical spatial boundaries. Both pyrolysis and distillation reactions are endothermic, meaning they require external heat to continue. The heat sustaining the reaction includes high-temperature flue gas flowing upwards in the opposite direction to the waste's movement. Although waste is a poor conductor of heat, the high-temperature flue gas seeps through the gaps in the waste layer, directly and fully contacting the waste, resulting in rapid heat absorption and pyrolysis.

[0040] Next, after the pyrolysis reaction, the volume of the waste is greatly reduced. The waste residue and solid products after the pyrolysis reaction move downward in the furnace and enter the deep combustion zone with a moderately oxygen-deficient atmosphere. They come into contact with the mixed-burning air once and undergo an incomplete oxidation reaction in the deep combustion zone to generate combustible components such as CO and H2 and non-combustible components such as CO2, and release heat.

[0041] Finally, the waste residue and solid products after deep combustion, such as refractory components, inert substances, and solid carbon in the waste, move downward in the furnace and enter the oxygen-rich combustion zone. In the combustion zone, they come into contact with the oxygen-containing primary combustion air and undergo a full oxidation reaction, releasing heat and forming ash with a very low loss on ignition. The ash enters the ash chamber through the gaps in the grate.

[0042] When the waste reacts in the furnace, a co-fuel air is introduced into the furnace through the air distribution system. A portion of this co-fuel air enters the ash chamber, absorbs some of the heat from the ash, and then rises through the grate into the burnout zone and the deep combustion zone, where it co-fuels with other co-fuel air entering the furnace. This maintains the continuous progress of various reactions in the burnout and deep combustion zones. The oxygen component in the co-fuel air is gradually consumed, and the temperature rises. Then, the co-fuel air enters the pyrolysis gasification zone, where the waste undergoes a pyrolysis reaction, forming pyrolysis gas containing combustible components. Finally, the co-fuel air enters the preheating and drying zone to preheat and dry the waste, and lower its temperature.

[0043] Preferably, the pyrolysis gasification method of the small-scale municipal solid waste pyrolysis gasification incinerator further includes the following steps:

[0044] When the value of the pyrolysis temperature sensor is higher than the set range, the flow rate of the primary combustion air is reduced, the range of the deep combustion zone is narrowed, the waste is directly burned in the furnace, and the initial temperature of the primary combustion air entering the furnace is reduced.

[0045] When the value of the pyrolysis temperature sensor is within the set range, maintain the flow rate of the primary combustion air and increase the initial temperature of the primary combustion air when it enters the furnace.

[0046] When the value of the pyrolysis temperature sensor is lower than the set range, the flow rate of the primary combustion air is increased to expand the range of the deep combustion zone, so that some of the waste is directly burned in the furnace and the initial temperature of the primary combustion air when it enters the furnace is increased.

[0047] Preferably, the pyrolysis gasification method of the small-scale municipal solid waste pyrolysis gasification incinerator further includes the following steps:

[0048] When the initial temperature of the primary combustion air entering the furnace reaches its maximum value, the value of the pyrolysis temperature sensor is lower than the set range, and the difference between the value of the primary combustion air and the value of the secondary combustion temperature sensor is less than the set value, the flow rate of the primary combustion air is increased, the secondary combustion air is shut off, and the operation of the secondary combustion chamber is stopped; or,

[0049] When the initial temperature of the primary combustion air entering the furnace reaches its maximum value, the value of the pyrolysis temperature sensor is lower than the set range, and the difference between the value of the primary combustion air and the value of the secondary combustion temperature sensor is less than the set value, the flow rate of the primary combustion air is increased, and auxiliary fuel is supplied to the secondary combustion chamber to maintain the operation of the secondary combustion chamber.

[0050] The energy balance relationship for the pyrolysis reaction of waste in the furnace is as follows:

[0051] The heat Q released by the waste in the deep combustion zone 深烧The heat Q released by the burnout zone 燃尽 The sum of these should be equal to the sensible heat Q required for the waste to heat up. 升温 The latent heat Q required for the evaporation of moisture from waste 蒸发 The amount of heat Q required for the pyrolysis reaction of waste 热解 The energy Q carried away by the flue gas discharged from the furnace 烟气 The heat Q carried away by the ash 灰渣 and the heat Q emitted by the furnace body 散失 The sum of these two equations achieves a balance, as shown in equation (1).

[0052] Q 深烧 +Q 燃尽 =Q 升温 +Q 蒸发 +Q 热解 +Q 烟气 +Q 灰渣 +Q 散失 (1)

[0053] However, in some cases, such as when the waste has a high moisture content, Q 蒸发 A higher value, or a lower carbon content in the residue after deep burning, Q 燃尽 When the value is small, the balance shown in equation (1) will be broken, that is, the heat released by the deep combustion zone and the burnout zone is insufficient to balance the heat absorbed by the pyrolysis gasification zone, and the pyrolysis reaction of the waste will move towards Q. 热解 Q 烟气 The trend of reducing waste to maintain energy balance leads to a gradual decrease in the proportion of waste undergoing pyrolysis and a drop in furnace temperature, until the waste is converted into an incomplete oxidation reaction in the furnace, i.e., smoldering. As a result, the combustible components of the flue gas discharged from the furnace decrease significantly, the secondary combustion chamber cannot operate, and the harmful pollutants in the flue gas increase dramatically, resulting in emissions exceeding standards.

[0054] To overcome this phenomenon, the present invention increases the temperature of the primary combustion air and inputs energy Q into the furnace. 输入 Furthermore, by enhancing heat exchange between a portion of the primary combustion air and the incandescent ash, a portion of the energy Q is recovered from the ash. 灰渣回收 Input is used to achieve the equilibrium shown in equation (2), which promotes the continuous pyrolysis reaction of waste in the furnace.

[0055] Q 输入 +Q 灰渣回收 +Q 深烧 +Q 燃尽 =Q 升温 +Q 蒸发 +Q 热解 +Q 烟气 +Q 灰渣 +Q 散失 (2)

[0056] When the method shown in equation (2) still cannot achieve balance, for example, when the moisture content of the waste is very high, the amount of primary combustion air supplied is increased so that some of the waste that has not been fully pyrolyzed is directly burned, that is, heat Q is released through oxidation reaction. 直燃 This achieves the equilibrium shown in equation (3), promoting the continuous pyrolysis reaction of waste in the furnace.

[0057] Q 直燃 +Q 输入 +Q 灰渣回热 +Q 深烧 +Q 燃尽 =Q 升温 +Q 蒸发 +Q 热解 +Q 烟气 +Q 灰渣 +Q 散失 (3)

[0058] In other words, under the above three conditions, the following methods are used to maintain the continuous pyrolysis reaction of waste in the furnace:

[0059] 1) When the moisture content of the waste is low, Q 蒸发 When it is small, make Q 直燃 ≈0, Q 输入 =0, meaning that the pyrolysis reaction of waste in the furnace can be guaranteed to continue without the need for direct combustion of waste to release heat or external energy input;

[0060] 2) When the moisture content of the waste is high, Q 蒸发 When it is large, make Q 直燃 ≈0, Q 输入 >0, meaning that there is no need for direct combustion of waste to release heat; only external energy input is needed to ensure that the pyrolysis reaction of waste in the furnace can continue.

[0061] 3) When the moisture content of the garbage is very high, Q 蒸发 When it is very large, Q 直燃 >0, Q 输入 >0, meaning that the heat released by direct combustion of waste and the external input of energy occur simultaneously to ensure that the pyrolysis reaction of waste in the furnace proceeds smoothly.

[0062] Preferably, the pyrolysis gasification method of the small-scale municipal solid waste pyrolysis gasification incinerator further includes the following steps:

[0063] When the ash collected in the ash chamber reaches the set amount and the ash needs to be discharged, the flow rate of the primary combustion air and the secondary combustion air is first reduced, and the ash discharge door is opened through the ash discharge door drive mechanism so that the ash collected in the ash chamber is discharged from the ash discharge port outside the furnace. Then the ash discharge door is closed and the flow rate of the primary combustion air is restored.

[0064] When the waste undergoes various reactions in the furnace and is reduced to a set amount, requiring replenishment, the flow rates of the primary and secondary combustion air are first reduced. The feed gate is then opened via the feed gate drive mechanism, allowing the replenished waste to enter the furnace through the feed inlet. The feed gate is then closed, and the flow rates of the primary and secondary combustion air are restored, thereby enabling the continuous operation of the pyrolysis reaction of the waste in the furnace.

[0065] The above-described solution of the present invention has at least the following beneficial effects:

[0066] The small-scale municipal solid waste pyrolysis gasification incinerator and pyrolysis gasification method of the present invention enable better and more continuous pyrolysis reactions of municipal solid waste within the furnace. This results in lower external energy input during the pyrolysis process, less fluctuation in the furnace reaction state, more stable pyrolysis gas composition and temperature, and lower ash loss on ignition. Consequently, it improves the incinerator's operating efficiency, promotes stable operation of the secondary combustion chamber, reduces the load impact on downstream flue gas treatment systems, and lowers overall operating costs. Specifically,

[0067] First, during operation, the feed door and ash discharge door of the small-scale municipal solid waste pyrolysis gasification incinerator are mostly closed, ensuring good airtightness of the furnace and facilitating the pyrolysis reaction of the waste.

[0068] Secondly, the small-scale municipal solid waste pyrolysis gasification incinerator forms an oxygen-free preheating and drying zone, an oxygen-free pyrolysis gasification zone, an oxygen-deficient deep combustion zone, and an oxygen-rich combustion zone from top to bottom in the furnace. Through the comprehensive application of multiple measures such as deep combustion, combustion, primary combustion with air to recover ash heat, and reducing furnace heat dissipation, it not only helps to reduce the external energy input required to maintain the pyrolysis reaction in the furnace and reduce operating costs, but also helps to reduce the heat loss rate of ash, thus having better economic and environmental benefits.

[0069] Third, the reaction of waste in the furnace of the small-scale municipal solid waste pyrolysis gasification incinerator can be maintained in a continuous state, overcoming the general mode of small-scale municipal solid waste pyrolysis gasification incinerators that can only operate in batches. Moreover, the waste is in direct contact with the high-temperature, deeply burned flue gas in the pyrolysis gasification zone, and the heat exchange rate is very fast. The pyrolysis reaction rate largely depends on the heat absorption rate of the waste, so the pyrolysis reaction of the waste is more rapid, thus more waste can be processed in the same amount of time, which is more conducive to the development of furnaces with larger processing capacity or the miniaturization of processing equipment.

[0070] Fourth, the reaction fluctuation of the waste in the furnace of the small-scale municipal solid waste pyrolysis gasification incinerator is very small, and the composition of the pyrolysis gas is relatively more stable. Therefore, the flame in the secondary combustion chamber is more stable, which greatly reduces the number of times the secondary combustion chamber is ignited. This not only helps to save costs, but also reduces the load impact on the purification and treatment of downstream high-temperature flue gas.

[0071] Fifth, in the reaction process of the waste in the furnace of the small-scale municipal solid waste pyrolysis gasification incinerator, different stages such as preheating and drying, pyrolysis and gasification, deep combustion, and burnout are carried out in different zones. After the waste enters the furnace, it passes through the preheating and drying zone, the pyrolysis zone, the deep combustion zone, and the burnout zone in sequence, which can achieve better reaction results and quality. The loss on ignition (LOI) of the ash residue after waste pyrolysis can be as low as below 3%, while the LOI of the ash residue from ordinary pyrolysis gasification processes is still difficult to reach the level of 5%.

[0072] Sixth, the small-scale municipal solid waste pyrolysis gasification incinerator not only increases the durability of the furnace body, but also reduces the heat dissipation of the furnace body, increases the strength of the furnace body, and lowers the temperature of the outer wall of the furnace body, thus reducing the possibility of burns to operators and improving safety. Attached Figure Description

[0073] Figure 1 This is a schematic diagram of the structure of the small-scale municipal solid waste pyrolysis gasification incinerator of the present invention;

[0074] Figure 2 yes Figure 1 A schematic diagram along direction A;

[0075] Figure 3 yes Figure 1 A magnified view of a portion of point I;

[0076] Figure 4 yes Figure 3 A partial sectional view along the BB direction;

[0077] Figure 5 yes Figure 1 A magnified view of part II in the state before ash discharge from the ash chamber;

[0078] Figure 6 yes Figure 1 A magnified view of part II in the state after the ash slag chamber has not been discharged;

[0079] Figure 7 This is a schematic diagram of the furnace body of the small-scale municipal solid waste pyrolysis gasification incinerator of the present invention;

[0080] Figure 8 This is a schematic diagram of the air distribution system of the small-scale municipal solid waste pyrolysis gasification incinerator of the present invention;

[0081] Figure 9 yes Figure 8 A magnified view of a portion of point I;

[0082] Figure 10 yes Figure 8 Axonometric drawing of the second air duct, vertical duct, and outward air outlet assembly of the air distribution system;

[0083] Figure 11 yes Figure 8 A magnified view of section II;

[0084] The components include: 1. Furnace body; 2. Furnace chamber; 3. Smoke collection pipe; 4. Air distribution system; 41. Circular air duct; 42. Main air supply pipe; 421. First air duct; 422. Second air duct; 423. Third air duct; 424. Vertical pipe; 43. Inward air outlet; 44. Outward air outlet; 45. First air supply; 46. Second air supply; 47. Third air supply; 5. Grate; 6. Ash chamber; 7. Slag collection hopper; 8. Slag discharge door; 9. Feed inlet; 10. Feed door; 11. Feed door drive mechanism; 12. Pyrolysis temperature sensor; 13. Pyrolysis gas output pipe; 14. Secondary combustion temperature sensor; 15. Flue gas pipe; 16. High-temperature flue gas; 17. Secondary combustion chamber; 18. Secondary combustion air blending; 19. Primary combustion air blending; 20. Slag discharge port; 21. Slag discharge door drive mechanism; 22. Outer shell. 23. Insulation layer; 24. Pyrolysis gas; 25. Anchoring; 26. Refractory layer; 27. Gas gathering channel; 271. First gas gathering channel plate; 272. Second gas gathering channel plate; 28. Ash and slag; 29. ​​Slag-blocking bar; 30. Preheating and drying zone; 31. Pyrolysis and gasification zone; 32. Deep combustion zone; 33. Combustion zone. Detailed Implementation

[0085] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0086] Example 1

[0087] like Figure 1-2 As shown, the small-scale municipal solid waste pyrolysis gasification incinerator proposed in the embodiment of the present invention includes: furnace body 1, grate 5, flue gas collection pipe 3, pyrolysis gas output pipe 13, secondary combustion chamber 17, and slag collection hopper 7.

[0088] The furnace body 1 has a hollow interior and a feed inlet 9 and a feed door 10 that can be sealed together with the feed inlet 9 at the top. In order to facilitate the control of the opening and closing state of the feed door 10, in this embodiment, a feed door drive mechanism 11 is provided between the feed door 10 and the top of the furnace body 1.

[0089] The grate 5 is located inside the furnace body 1 and divides the cavity of the furnace body 1 into an upper furnace chamber 2 and a lower ash chamber 6; that is, the space enclosed by the grate 5, the inner surface of the side wall of the furnace body 1, the top, and the feed door 10 is the furnace chamber 2, and the space enclosed by the grate 5, the inner surface of the side wall of the furnace body 1, the inner surface of the slag collection hopper 7, and the slag discharge door 8 is the ash chamber 6; an air distribution system 4 is provided at the grate 5;

[0090] The smoke collecting pipe 3 is located on the inner side wall of the furnace body 1 and communicates with the furnace chamber 2 through the gas gathering channel 27; wherein, as Figure 3 As shown, the gas-gathering channel 27 is composed of a first gas-gathering channel plate 271 and a second gas-gathering channel plate 272; one end of the first gas-gathering channel plate 271 is fixed to the inner wall of the furnace body 1, and the other end is a free end, extending towards the second gas-gathering channel plate 272; one end of the second gas-gathering channel plate 272 is fixed to the inner wall of the furnace body 1, and the other end is a free end, extending towards the first gas-gathering channel plate 271; the first gas-gathering channel plate 271 and the second gas-gathering channel plate 272 form an acute angle, and a gap suitable for gas passage towards the bottom of the furnace body 1 is formed at the free ends of the first gas-gathering channel plate 271 and the second gas-gathering channel plate 272.

[0091] The pyrolysis gas output pipe 13 is located on the outer side wall of the furnace body 1 and is connected to the smoke collection pipe 3;

[0092] The inlet of the secondary combustion chamber 17 is connected to the pyrolysis gas output pipe 13, and the outlet is provided with a flue gas pipe 15;

[0093] The slag collection hopper 7 is located at the bottom of the furnace body 1, and is provided with a slag discharge port 20 and a slag discharge door 8 that can be sealed and fitted with the slag discharge port 20. In order to facilitate the control of the opening and closing state of the slag discharge door 8, in this embodiment, a slag discharge door drive mechanism 21 is provided between the slag discharge door 8 and the slag collection hopper 7.

[0094] To facilitate the determination of the rate of chemical reaction of waste in the furnace and thus provide a basis for decision-making to improve the energy balance of the furnace, in this embodiment, a pyrolysis temperature sensor 12 is provided on the pyrolysis gas output pipe 13. As a preferred implementation of this embodiment, a secondary combustion temperature sensor 14 is provided on the flue gas pipe 15. Based on the data from the secondary combustion temperature sensor 14 and in combination with the data from the pyrolysis temperature sensor 12, the calorific value of the combustible gas components in the pyrolysis gas can be determined, thereby determining the chemical reaction state of the waste in the furnace 2, and thus providing a basis for decision-making to optimize the reaction process within the furnace.

[0095] The geometric center of the feed inlet 9 coincides with the geometric center of the top of the furnace body 1. This arrangement improves the symmetry of the waste layer after it enters the furnace chamber 2 along the centerline of the furnace, preventing the waste layer from converging on one side of the furnace body 1 and causing flow problems in the furnace, which would be detrimental to various reactions.

[0096] like Figure 4 As shown, the sidewall of the furnace body 1 is provided with an outer shell 22, an insulation layer 23, and a refractory layer 26 in sequence from the outside to the inside. The three-layer structure not only increases the durability of the furnace body 1, but also reduces the heat dissipation of the furnace body 1 and increases the strength of the furnace body 1.

[0097] In a preferred embodiment, an anchor 25 is provided between the refractory layer 26 and the outer shell 22. One end of the anchor 25 is fixed to the outer shell 22, and the other end is embedded in the refractory layer 26. The anchor 25 effectively prevents the refractory layer 26 from falling off, making the furnace body refractory layer more robust. In this embodiment, the end of the anchor 25 embedded in the refractory layer 26 is "L"-shaped, which makes it more stable and less prone to falling off. It should be noted that the specific structural design of the anchor 25 is not unique; the end of the anchor 25 embedded in the refractory layer 26 can also be "T"-shaped.

[0098] In a preferred embodiment, the slag collecting hopper 7 is provided with slag-blocking bars 29, which are disposed on the inner surface of the slag collecting hopper 7. Each time ash and slag are discharged, due to the obstruction effect of the slag-blocking bars 29, some residual ash and slag remain in the ash and slag chamber 6, such as... Figure 5-6 As shown, the retained cold ash can separate the subsequently falling hot ash 28 from the inner wall of the ash collection hopper 7, or reduce the possibility of hot ash contacting the inner wall of the ash collection hopper. Since ash is a poor conductor of heat, it can reduce the surface temperature of the outer wall of the ash collection hopper 7, improve the operating safety of the incinerator, reduce the heat dissipation of ash, and make it more conducive to the ideal reaction of waste in the furnace.

[0099] As a preferred implementation of this embodiment, such as Figure 8-11 As shown, the air distribution system 4 includes an annular air duct 41 and a main air supply duct 42. The annular air duct 41 is arranged around the inside of the side wall of the furnace body 1 and has inward air inlets 43 that communicate with the furnace chamber 2. The gas outlet of the inward air inlets 43 points towards the center line of the furnace chamber 2. The main air supply duct 42 is located outside the furnace body 1 and has a first air duct 421, a second air duct 422, and a third air duct 423. The first air duct 421 passes through the side wall of the furnace body 1 and communicates with the annular air duct 41. The second air duct 422 passes through the side wall of the furnace body 1 and extends to the ash chamber 6. The second air duct 422 has a connection to the ash chamber 6. A vertical pipe 424 is connected; the vertical pipe 424 passes through the grate 5 and extends to the furnace 2, and is provided with an outward air outlet 44 that communicates with the furnace 2; the gas outlet of the outward air outlet 44 points to the surrounding side wall of the furnace 2; the third air duct 423 passes through the side wall of the slag collection hopper 7 and extends to the ash chamber 6.

[0100] One type of combustion air 19 enters the main air supply pipe 42 and is divided into three air paths:

[0101] The first airflow 45 enters the annular airflow 41 through the first airflow duct 421, and then enters the deep combustion zone of the furnace 2 through the inward airflow vent 43 to participate in waste combustion;

[0102] The second airflow 46 enters the vertical pipe 424 via the second air duct 422, and then enters the deep combustion zone of the furnace 2 through the outward air outlet 44 to participate in the combustion of waste pyrolysis residues.

[0103] The third airflow 47 enters the ash chamber 6 through the third air duct 423, where it exchanges heat with the ash and flows upward, passing through the gaps in the grate 5 and entering the combustion zone of the furnace 2 to participate in the combustion of the waste residue.

[0104] The co-firing air is actively delivered to different reaction zones in the furnace in three separate streams to maintain the waste reaction. The flow field inside the furnace is actively controlled, and the oxygen supply to the corresponding areas can be actively controlled according to the oxygen demand of the waste in different reaction zones. This is beneficial to improving the stability of the flow field in the furnace, optimizing the waste reaction process, reducing the external energy consumption of various reactions of waste and the heat loss rate of ash, improving the compositional stability of pyrolysis gas and the smooth operation of the secondary combustion chamber, facilitating further treatment of pyrolysis gas, and creating favorable conditions for the incinerator to achieve better emission levels.

[0105] In a preferred embodiment, the distance between the gas outlet of the outward-blowing vent 44 and the centerline of the furnace 2 increases uniformly from top to bottom along the vertical pipe 424. This arrangement ensures that the lower the gas outlet of the outward-blowing vent 44 is, the closer it is to the grate 5, the farther its gas outlet is from the centerline of the furnace 2. This results in all the outward-blowing vents 44 forming a roughly "pagoda" shape. This structure is more conducive to the entry of waste pyrolysis residue into the deep combustion zone, and makes the waste residue entering the burnout zone more dispersed. Furthermore, the gas distribution in the second air duct 422 is more uniform, which can accelerate the reaction speed in both the deep combustion zone and the burnout zone.

[0106] The structural design of the outward air outlet 44 is not unique. In this embodiment, a specific design is provided. The vertical pipe 44 is located on the center line of the furnace 2, and the outward air outlet 44 is an air pipe provided on the vertical pipe 424. The air pipe is arranged circumferentially from top to bottom along the vertical pipe 424, and the length of the air pipe at the higher horizontal position is less than the length of the air pipe at the lower horizontal position, so that the distance between the gas outlet of the air pipe and the center line of the furnace 2 increases uniformly from top to bottom.

[0107] To create an ideal flow field, the gas outlet direction of the inward air vent 43 is inclined upwards. That is, the gas outlet direction of the inward air vent 43 points obliquely upwards towards the centerline of the furnace 2. The gas outlet direction of the inward air vent 43 has an angle α between 20° and 45° with the horizontal plane. An angle α within this range is beneficial for a more uniform distribution of gas from the first air duct within the deep combustion zone, thereby improving the deep combustion effect of the waste pyrolysis residue.

[0108] The working process of the small-scale municipal solid waste pyrolysis gasification incinerator described in this embodiment is as follows:

[0109] The feed gate 10 is opened by the feed gate drive mechanism 11, allowing the waste to be processed to enter the furnace 2 from the feed inlet 9. Then the feed gate 10 is closed to prevent outside air from entering the furnace. The primary combustion air 19 enters the furnace 2 through the air distribution system 4 to maintain the series of reactions of the waste in the furnace 2. After a series of reactions such as preheating, drying, pyrolysis, deep burning, and burnout in the furnace 2, the waste forms ash 28 and pyrolysis gas 24 containing organic combustible components. The ash 28 falls into the ash chamber 6 from the gaps in the grate 5.

[0110] The pyrolysis gas 24 enters the flue gas collecting pipe 3 through the gas gathering channel 27, and then enters the secondary combustion chamber 17 through the pyrolysis gas output pipe 13. The pyrolysis gas 24 mixes with the secondary combustion air 18 that enters the secondary combustion chamber 17 simultaneously, forming an oxygen-rich atmosphere in the secondary combustion chamber 7. The combustible components in the atmosphere undergo an oxidation reaction, releasing heat and converting the pyrolysis gas 24 into high-temperature flue gas 16 with a higher temperature and a very low concentration of organic pollutants. This high-temperature flue gas 16 is then discharged through the high-temperature flue gas pipe 15 or discharged downstream. The temperature of the high-temperature flue gas 16 is 850℃-930℃.

[0111] When the ash 28 collected in the ash chamber 6 reaches the set amount and needs to be discharged, the flow rates of the primary combustion air 19 and the secondary combustion air 18 are first reduced, and the ash discharge door 8 is opened through the ash discharge door drive mechanism 21, so that the ash 28 collected in the ash chamber 6 is discharged from the ash discharge port 20 outside the furnace. Then the ash discharge door 8 is closed and the flow rate of the primary combustion air 19 is restored.

[0112] When the waste undergoes various reactions in the furnace 2 and is reduced to a set amount, and when it needs to be replenished, the flow rates of the primary combustion air 19 and the secondary combustion air 18 are first reduced. The feed gate 10 is then opened through the feed gate drive mechanism 11, allowing the replenished waste to enter the furnace 2 from the feed inlet 9. The feed gate 9 is then closed, and the flow rates of the primary combustion air 19 and the secondary combustion air 18 are restored, thereby enabling the continuous operation of the pyrolysis reaction of the waste in the furnace.

[0113] Example 2

[0114] The pyrolysis gasification method of the small-scale municipal solid waste pyrolysis gasification incinerator in this embodiment is as follows: Figure 7 As shown, this is achieved using the small-scale municipal solid waste pyrolysis gasification incinerator described in Example 1, which includes the following steps:

[0115] The waste moves from top to bottom within the furnace 2, forming an oxygen-free preheating and drying zone 30, an oxygen-free pyrolysis and gasification zone 31, an oxygen-deficient deep combustion zone 32, and an oxygen-rich combustion zone 33 from top to bottom within the furnace 2.

[0116] Specifically, when the waste enters the furnace 2, it first enters the preheating and drying zone 30, which is an oxygen-free atmosphere (here, "oxygen-free" refers to an extremely oxygen-deficient state with almost no oxygen). The waste is preheated and dried in the preheating and drying zone 30. During the preheating and drying process, the waste gradually moves towards the pyrolysis and gasification zone 31, which is an oxygen-free atmosphere, and further absorbs heat and rises to above 110°C, causing the moisture in the waste to evaporate further and some organic polymer components to approach the decomposition state.

[0117] Then, the waste enters the pyrolysis gasification zone 31. In the pyrolysis gasification zone 31, the waste further absorbs heat and heats up to the temperature range where the pyrolysis reaction can occur, and the pyrolysis reaction begins. The pyrolysis reaction includes the cracking reaction of the organic polymer components in the waste and the dry distillation reaction of the biomass components. Specifically, the organic polymer components in the waste, such as various plastics and rubbers, will undergo a cracking reaction when heated in an anaerobic atmosphere, generating combustible gases such as C2H4, C2H6, CH4, and H2, as well as carbon black, which is the so-called gasification reaction. The composition of the products varies at different temperatures. The higher the cracking temperature, the smaller the product molecules. The cracking reaction generally takes place in the temperature range of 280℃-650℃. At the same time, the biomass components in the waste, such as leaves and wood, will undergo a dry distillation reaction in an anaerobic atmosphere, generating gaseous wood tar in the furnace, wood gas containing combustible components such as CH4, H2, and CH3OH, as well as solid carbon, which is the so-called carbonization reaction. Carbonization reactions typically occur within a temperature range of 250℃-600℃, similar to the principle of common wood charcoal production. The aforementioned reactions are highly complex, with various reactions intertwined and lacking clear temperature, time, or physical spatial boundaries. Both pyrolysis and distillation reactions are endothermic, meaning they require external heat to continue. The heat sustaining the reaction includes high-temperature flue gas flowing upwards in the opposite direction to the waste's movement. Although waste is a poor conductor of heat, the high-temperature flue gas seeps through the gaps in the waste layer, directly and fully contacting the waste, resulting in rapid heat absorption and pyrolysis.

[0118] Next, the waste residue and solid products after the pyrolysis reaction move downward in the furnace 2 and enter the deep combustion zone 32 with a moderately oxygen-deficient atmosphere. They come into contact with the mixed combustion air and undergo an incomplete oxidation reaction in the deep combustion zone 32 to generate combustible components such as CO and H2 and non-combustible components such as CO2, and release heat.

[0119] Finally, the waste residue and solid products after deep combustion, such as refractory components, inert substances, and solid carbon in the waste, move downward in the furnace 2 and enter the oxygen-rich combustion zone 33. In the combustion zone 33, they come into contact with the oxygen-containing mixed combustion air and undergo a full oxidation reaction, releasing heat and forming ash 28 with a very low loss on ignition. The ash 28 enters the ash chamber 6 through the gaps in the grate 5.

[0120] It can be seen that the movement of the waste and its reaction products and residues in the furnace 2 is a gradual downward movement, and the morphological change process is from raw waste to dry waste, pyrolysis residues, deep combustion residues, and ash 28.

[0121] In a preferred embodiment, when the waste reacts in the furnace 2, a co-firing air 19 is introduced into the furnace 2 through the air distribution system 4. A portion of the co-firing air 19 enters the ash chamber 6, absorbs some of the heat from the ash 28, and then passes upwards through the grate 5 into the burnout zone 33 and the deep combustion zone 32, where it co-fires with other co-firing air entering the furnace. This maintains the continuous progress of various reactions in the burnout zone 33 and the deep combustion zone 32. The oxygen component in the co-firing air 19 is gradually consumed, and the temperature rises. Then, the co-firing air 19 enters the pyrolysis gasification zone 31, causing the waste to undergo a pyrolysis reaction, forming pyrolysis gas 24 containing combustible components. Finally, the co-firing air 19 enters the preheating and drying zone 30 to preheat and dry the waste, and lower its temperature.

[0122] It can be seen that the movement of the combustion air 19 within the furnace 2 is gradually upward, its temperature changes by first rising and then falling, and its oxygen content changes by gradually decreasing to zero.

[0123] As a preferred implementation of this embodiment, controlling the reaction of waste within the furnace 2 includes the following steps:

[0124] When the value of the pyrolysis temperature sensor 12 is higher than the set range, the flow rate of the primary combustion air 19 is reduced, the range of the deep combustion zone 32 is reduced, and the initial temperature of the primary combustion air 19 when it enters the furnace is lowered.

[0125] When the value of the pyrolysis temperature sensor 12 is higher than the set range, that is, the temperature of the pyrolysis gas 24 is too high and the moisture content of the waste in the furnace 2 is very low, at this time, the flow rate of the co-firing air 19 is appropriately reduced, the range of the deep combustion zone 32 is reduced, and the waste is prevented from being directly burned. At the same time, the initial temperature of the co-firing air 19 when it enters the furnace is reduced. For example, the auxiliary heating device for heating the co-firing air 19 is turned off, and the auxiliary energy input to the furnace 2 is reduced.

[0126] When the value of the pyrolysis temperature sensor 12 is within the set range, the flow rate of the primary combustion air 19 is maintained, and the initial temperature of the primary combustion air 19 when it enters the furnace is increased.

[0127] When the value of the pyrolysis temperature sensor 12 is within the set range, that is, the temperature of the pyrolysis gas 24 is high and the moisture content of the waste in the furnace 2 is high, at this time, the flow rate of the primary combustion air 19 should be slightly reduced to reduce the possibility of direct combustion of the waste. However, the auxiliary heating device of the primary combustion air 19 should be activated to input auxiliary energy into the furnace 2.

[0128] When the value of the pyrolysis temperature sensor 12 is lower than the set range, the flow rate of the primary combustion air 19 is increased to expand the range of the deep combustion zone 32, so that some of the waste is directly burned in the furnace and the initial temperature of the primary combustion air 19 when it enters the furnace is increased.

[0129] If the value of the pyrolysis temperature sensor 12 is lower than the set range, that is, the temperature of the pyrolysis gas 24 is too low and the moisture content of the waste in the furnace 2 is very high, then the flow rate of the co-firing air 19 is increased to expand the range of the deep combustion zone 32, promote the direct combustion of some waste in the furnace, and increase the initial temperature of the co-firing air 19 when it enters the furnace. For example, an auxiliary heating device is used and its power is increased to input more auxiliary energy into the furnace 2 to promote the pyrolysis reaction of the waste.

[0130] In a preferred implementation of this embodiment, when the initial temperature of the primary combustion air 19 entering the furnace reaches its maximum value, the value of the pyrolysis temperature sensor 12 is lower than the set range, and the difference between the value of the primary combustion air 19 and the value of the secondary combustion temperature sensor 14 is less than the set value, the flow rate of the primary combustion air 19 is increased, the secondary combustion air 18 is shut off, and the operation of the secondary combustion chamber 17 is stopped; or, auxiliary fuel is supplied to the secondary combustion chamber 17 to maintain the operation of the secondary combustion chamber 17.

[0131] When the initial temperature of the primary combustion air 19 enters the furnace reaches its maximum value, that is, the auxiliary heating device of the primary combustion air 19 has reached its maximum power. The pyrolysis temperature sensor 12 detects that the temperature of the pyrolysis gas 24 is still lower than the set range. When the difference between the values ​​of the pyrolysis temperature sensor 12 and the secondary combustion temperature sensor 14 is less than the set value, for example, approaching zero, it indicates that the moisture content of the waste is extremely high at this time, and the pyrolysis reaction can no longer take place in the furnace 2. The flow rate of the primary combustion air 19 is further increased, and the secondary combustion air 18 is shut off or auxiliary fuel is supplied to the secondary combustion chamber 17, so that the reaction of the waste in the furnace is completely converted into an oxidation reaction.

[0132] It should also be noted that the small-scale municipal solid waste pyrolysis gasification incinerator and pyrolysis gasification method described in this invention are mainly used in small-scale municipal solid waste incinerators, but can also be used in other applications, including but not limited to medium-sized municipal solid waste incinerators, medical waste incinerators, industrial solid waste incinerators, etc.

[0133] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A small-scale municipal solid waste pyrolysis gasification incinerator, characterized in that, include: The furnace body (1) has a cavity inside and a feed inlet (9) and a feed door (10) that can be sealed and fitted with the feed inlet (9) at the top. A grate (5) is located inside the furnace body (1) and divides the cavity of the furnace body (1) into an upper furnace chamber (2) and a lower ash chamber (6); an air distribution system (4) is provided at the grate (5). The smoke collection pipe (3) is located on the inner side wall of the furnace body (1) and is connected to the furnace chamber (2) through the gas gathering channel (27); The pyrolysis gas output pipe (13) is located on the outer side wall of the furnace body (1) and is connected to the smoke collection pipe (3); A secondary combustion chamber (17) is provided with an inlet connected to the pyrolysis gas output pipe (13) and an outlet provided with a flue gas pipe (15). Slag collection hopper (7), the slag collection hopper (7) is located at the bottom of the furnace body (1), and is provided with slag discharge port (20) and slag discharge door (8) that can be sealed and fitted with the slag discharge port (20). The air distribution system (4) includes an annular air duct (41) and a main air supply duct (42). The annular air duct (41) is arranged around the inside of the side wall of the furnace body (1) and has an inward air inlet (43) that communicates with the furnace chamber (2) in the circumferential direction. The gas outlet of the inward air inlet (43) points to the center line of the furnace chamber (2). The main air supply duct (42) is located outside the furnace body (1) and has a first air duct (421), a second air duct (422), and a third air duct (423). The first air duct (421) passes through the side wall of the furnace body (1) and connects with the annular air duct. The second air duct (422) passes through the side wall of the furnace body (1) and extends to the ash chamber (6); the second air duct (422) is provided with a vertical pipe (424) that communicates with the ash chamber (6); the vertical pipe (424) passes through the grate (5) and extends to the furnace (2), and is provided with an outward air outlet (44) that communicates with the furnace (2); the gas outlet of the outward air outlet (44) points to the surrounding side wall of the furnace (2); the third air duct (423) passes through the side wall of the slag collection hopper (7) and extends to the ash chamber (6). One type of combustion air (19) enters the main air supply pipe (42) and is divided into three air paths: The first airflow (45) enters the annular airflow (41) through the first airflow duct (421), and then enters the deep combustion zone of the furnace (2) through the inward airflow port (43) to participate in the combustion of waste; The second airflow (46) enters the vertical pipe (424) through the second air duct (422), and then enters the deep combustion zone of the furnace (2) through the outward air outlet (44) to participate in the combustion of the waste pyrolysis residue. The third air (47) enters the ash chamber (6) through the third air duct (423), and while exchanging heat with the ash, it turns upward and flows through the gap of the grate (5) into the combustion zone of the furnace (2) to participate in the combustion of the waste deep incineration residue; The distance between the gas outlet of the outward blowing port (44) and the center line of the furnace (2) increases uniformly from top to bottom along the vertical pipe (424); The vertical pipe (424) is located on the center line of the furnace (2), and the outward air outlet (44) is an air pipe provided on the vertical pipe (424); the air pipe is arranged circumferentially from top to bottom along the vertical pipe (424), and the length of the air pipe at the higher horizontal position is less than the length of the air pipe at the lower horizontal position. The gas outlet direction of the inward blowing port (43) is obliquely upward pointing to the center line of the furnace (2), and the gas outlet direction of the inward blowing port (43) has an angle α of 20°-45° with the horizontal plane; The gas-gathering channel (27) includes a first gas-gathering channel plate (271) and a second gas-gathering channel plate (272); one end of the first gas-gathering channel plate (271) is fixed to the inner wall of the furnace body (1), and the other end is a free end, extending towards the second gas-gathering channel plate (272); one end of the second gas-gathering channel plate (272) is fixed to the inner wall of the furnace body (1), and the other end is a free end, extending towards the first gas-gathering channel plate (271); the first gas-gathering channel plate (271) and the second gas-gathering channel plate (272) form an acute angle, and a gap suitable for gas passage towards the bottom of the furnace body (1) is formed at the free ends of the first gas-gathering channel plate (271) and the second gas-gathering channel plate (272); The slag collection hopper (7) is provided with a slag-blocking strip (29) inside. The slag-blocking strip (29) is provided on the inner surface of the slag collection hopper (7). The slag-blocking strip (29) is used to block the slag each time it is discharged, so that there is slag remaining in the slag cavity (6).

2. The small-scale municipal solid waste pyrolysis gasification incinerator according to claim 1, characterized in that, A feed gate drive mechanism (11) is provided between the feed gate (10) and the top of the furnace body (1); and / or, a slag discharge gate drive mechanism (21) is provided between the slag discharge gate (8) and the slag collection hopper (7).

3. The small-scale municipal solid waste pyrolysis gasification incinerator according to claim 1, characterized in that, A pyrolysis temperature sensor (12) is provided on the pyrolysis gas output pipe (13); and / or, a secondary combustion temperature sensor (14) is provided on the flue gas pipe (15).

4. The small-scale municipal solid waste pyrolysis gasification incinerator according to claim 1, characterized in that, The side wall of the furnace body (1) is provided with an outer shell (22), an insulation layer (23) and a refractory layer (26) from the outside to the inside.

5. The small-scale municipal solid waste pyrolysis gasification incinerator according to claim 4, characterized in that, An anchor (25) is provided between the fire-resistant layer (26) and the outer shell (22). One end of the anchor (25) is fixed to the outer shell (22), and the other end is embedded in the fire-resistant layer (26).

6. The small-scale municipal solid waste pyrolysis gasification incinerator according to claim 5, characterized in that, The end of the anchor (25) embedded in the fire-resistant layer (26) is "L" shaped or "T" shaped.

7. A pyrolysis gasification method for a small-scale municipal solid waste pyrolysis gasification incinerator, implemented using the small-scale municipal solid waste pyrolysis gasification incinerator described in any one of claims 1 to 6, characterized in that, The process includes the following steps: the waste moves from top to bottom in the furnace (2) and forms from top to bottom a preheating and drying zone (30) with an oxygen-free atmosphere, a pyrolysis and gasification zone (31) with an oxygen-free atmosphere, a deep combustion zone (32) with an oxygen-deficient atmosphere, and a burnout zone (33) with an oxygen-rich atmosphere.

8. The pyrolysis gasification method for a small-scale municipal solid waste pyrolysis gasification incinerator according to claim 7, characterized in that, It also includes the following steps: When the value of the pyrolysis temperature sensor (12) is higher than the set range, the flow rate of the primary combustion air (19) is reduced, the range of the deep combustion zone (32) is narrowed, and the initial temperature of the primary combustion air (19) when it enters the furnace is lowered. When the value of the pyrolysis temperature sensor (12) is within the set range, the flow rate of the primary combustion air (19) is maintained, and the initial temperature of the primary combustion air (19) when it enters the furnace is increased. When the value of the pyrolysis temperature sensor (12) is lower than the set range, the flow rate of the primary combustion air (19) is increased, the range of the deep combustion zone (32) is expanded, some of the waste is directly burned in the furnace, and the initial temperature of the primary combustion air (19) when it enters the furnace is increased.

9. The pyrolysis gasification method for a small-scale municipal solid waste pyrolysis gasification incinerator according to claim 8, characterized in that, It also includes the following steps: When the initial temperature of the primary combustion air (19) entering the furnace reaches its maximum value, the value of the pyrolysis temperature sensor (12) is lower than the set range, and the difference between the value of the primary combustion air (12) and the value of the secondary combustion temperature sensor (14) is less than the set value, the flow rate of the primary combustion air (19) is increased, and the secondary combustion air (18) is shut off, stopping the operation of the secondary combustion chamber (17); or, When the initial temperature of the primary combustion air (19) enters the furnace reaches its maximum value, the value of the pyrolysis temperature sensor (12) is lower than the set range, and the difference between the value of the primary combustion air (19) and the value of the secondary combustion temperature sensor (14) is less than the set value, the flow rate of the primary combustion air (19) is increased, and auxiliary fuel is supplied to the secondary combustion chamber (17) to maintain the operation of the secondary combustion chamber (17).

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