WO2025190432A1 - Municipal solid waste treatment system, method and apparatus - Google Patents

Abstract

Disclosed in the present invention are a municipal solid waste treatment system, method and apparatus. The municipal solid waste treatment system comprises: a pretreatment device; a pyrolysis device, which comprises a pyrolysis and gasification furnace and a feeder, wherein the feeder feeds pretreated waste into the pyrolysis and gasification furnace where the waste is pyrolyzed to generate pyrolysis gas and slag, and the feeder comprises a box body, the box body comprising a feeding door, a discharging door and an isolation door, and when the feeding door, the isolation door and the discharging door are all in closed states, the box body being divided into a sealed feeding bin and a sealed discharging bin; a pyrolysis gas purification device, which is used for removing harmful substances from the pyrolysis gas and separating macromolecular organics from small-molecule combustible gases, the macromolecular organics being further subjected to pyrolysis, and the small-molecule combustible gases being collected into a storage device; and a slag sorting device, which is used for sorting the slag into metal, incompletely pyrolyzed organics and slag ash, the incompletely pyrolyzed organics being further subjected to pyrolysis. By means of the municipal solid waste treatment system, the maximum utilization of energy and resources in waste treatment is realized.

Description

Domestic waste treatment system, method and equipment

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese patent application No. 2024113106667, filed on September 19, 2024, entitled “Feeding device for cracking gasifier and method thereof”, and Chinese patent application No. 2024222927409, filed on September 19, 2024, entitled “Feeding device for cracking gasifier”, and application number 2024222927409, and all disclosed contents of the above patent applications are incorporated into this application by reference.

Technical Field

The present invention relates to the technical field of waste disposal, and in particular to a system, method and equipment for disposing of domestic waste.

Background Art

Common methods of treating domestic waste include landfill, incineration and composting. Landfill and composting have fallen into the dilemma of occupying a large amount of land, low resource utilization level, and long-term damage to land and groundwater. Although incineration can achieve the goals of reducing volume and amount and utilizing resources, there are problems of pollution from harmful substances such as dioxins and the large amount of funds required for treatment.

The emergence of domestic waste cracking technology has provided a new idea and solution for waste disposal. Specifically, domestic waste needs to be dried, sorted, and crushed before being put into a cracking furnace. The waste is cracked in the high-temperature environment of the cracking furnace, and cracking gas and slag are generated during the cracking process. The cracking gas enters the secondary combustion chamber and directly burns to generate heat and produces flue gas or tail gas and fly ash. The generated heat energy is further converted into electrical energy. The generated flue gas or tail gas needs to be purified before it can be discharged, and the generated fly ash needs to be solidified and landfilled together with the slag.

However, the existing domestic waste cracking technology not only cannot achieve the reuse of slag, resulting in low resource utilization, but also cannot directly use the cracking gas as electricity or other energy. The secondary conversion of energy leads to low energy efficiency utilization, and the landfill of fly ash and slag requires additional high fees, which not only wastes land resources but also increases waste disposal costs.

Summary of the Invention

The main purpose of the present invention is to provide a system, method and equipment for treating domestic waste, so as to solve the problem of low utilization rate of energy and resources generated by cracking in the prior art.

According to an embodiment of the present invention, a domestic waste treatment system is proposed, which includes: a pretreatment device, which pre-treats domestic waste, and the pretreatment includes: dehydration, drying, sorting and crushing; a cracking device, which includes: a cracking gasification furnace and a feeder arranged above the cracking gasification furnace, and the feeder feeds the pre-treated domestic waste into the cracking gasification furnace for cracking and generating cracking gas and slag; wherein, the feeder includes a box body, and the box body includes: a feed door at the upper end, a discharge door at the lower end, and an isolation door located in the middle between the feed door and the discharge door; wherein, the feed door, the discharge door and the isolation door are connected to each other. When the isolation door and the discharge door are both closed, the box body is divided into a sealed upper hopper and a lower hopper; a cracking gas purification device, which removes chlorine-containing compounds and sulfur-containing compounds in the cracking gas, and cools the cracking gas to separate large molecular organic matter and small molecular combustible gas. The large molecular organic matter is sent back to the cracking gasifier for further cracking, and the small molecular combustible gas is collected in an external storage device; a slag sorting device, which sorts the slag into metal, incompletely cracked organic matter and slag ash, and sends the incompletely cracked organic matter back to the cracking gasifier for further cracking.

The cracked gas purification device further comprises a spray water washing structure, which reduces the temperature of the cracked gas and changes the macromolecular organic matter from gas to liquid, solid-liquid mixed state or solid state, so as to separate the macromolecular organic matter and small molecular combustible gas in the cracked gas.

Among them, the feeder includes the following three modes: a first mode, in which the feed door is in an open state, and the isolation door and the discharge door are in a closed state; a second mode, in which the feed door is in a closed state, the isolation door is in an open state, and the discharge door is in a closed state; a third mode, in which the feed door and the isolation door are in a closed state, and the discharge door is in an open state.

Wherein, the feeder is a vertical feeder or a horizontal feeder, the discharge door of the vertical feeder is arranged along the horizontal direction, and the discharge door of the horizontal feeder is arranged along the vertical direction.

Wherein, the horizontal feeder also includes a propeller, which is arranged opposite to the discharge door. The propeller pushes the domestic waste falling from the upper hopper into the lower hopper in a horizontal direction, so that the domestic waste falls into the cracking gasification furnace.

Wherein, at least two of the horizontal feeders are evenly arranged above the feed port on the side wall of the cracking gasifier.

Wherein, the vertical feeder is arranged above the center of the feed port of the cracking gasifier.

Wherein, the feed door is a single-side push-pull structure with the open end arranged horizontally or tilted downward.

Wherein, the volume of the lower silo is greater than the volume of the upper silo.

The small molecule combustible gases include carbon monoxide, hydrogen, methane and small molecule hydrocarbons.

According to an embodiment of the present invention, a method for treating domestic waste is further proposed, which comprises: pre-treating domestic waste, wherein the pre-treatment comprises: dehydration, drying, sorting and crushing; cracking the domestic waste by a cracking device, wherein the cracking device comprises: a cracking gasification furnace and a feeder arranged above the cracking gasification furnace, wherein the feeder feeds the pre-treated domestic waste into the cracking gasification furnace for cracking and generating cracking gas and slag; wherein the feeder comprises a box body, wherein the box body comprises: a feed door at the upper end, a discharge door at the lower end, and a container located between the feed door and the discharge door. an isolation door in the middle; wherein, the feed door, the isolation door and the discharge door are all in the closed state, dividing the box body into a sealed upper hopper and a lower hopper; removing chlorine-containing compounds and sulfur-containing compounds in the cracking gas, and cooling the cracking gas to separate large molecular organic matter and small molecular combustible gas, the large molecular organic matter is sent back to the cracking gasifier for further cracking, and the small molecular combustible gas is collected in an external storage device; the slag is sorted into metal, incompletely cracked organic matter and slag ash, and the incompletely cracked organic matter is sent back to the cracking gasifier for further cracking.

The cracked gas purification device further comprises a spray water washing structure, which reduces the temperature of the cracked gas and changes the macromolecular organic matter from gas to liquid, solid-liquid mixed state or solid state, so as to separate the macromolecular organic matter and small molecular combustible gas in the cracked gas.

Among them, the feeder includes the following three modes: a first mode, in which the feed door is in an open state, and the isolation door and the discharge door are in a closed state; a second mode, in which the feed door is in a closed state, the isolation door is in an open state, and the discharge door is in a closed state; a third mode, in which the feed door and the isolation door are in a closed state, and the discharge door is in an open state.

Wherein, the feeder is a vertical feeder or a horizontal feeder, the discharge door of the vertical feeder is arranged along the horizontal direction, and the discharge door of the horizontal feeder is arranged along the vertical direction.

Wherein, the horizontal feeder also includes a propeller, which is arranged opposite to the discharge door. The propeller pushes the domestic waste falling from the upper hopper into the lower hopper in a horizontal direction, so that the domestic waste falls into the cracking gasification furnace.

Wherein, at least two of the horizontal feeders are evenly arranged above the feed port on the side wall of the cracking gasifier.

Wherein, the vertical feeder is arranged above the center of the feed port of the cracking gasifier.

Wherein, the feed door is a single-side push-pull structure with the open end arranged horizontally or tilted downward.

According to an embodiment of the present invention, a feeder for a cracking gasification furnace in a domestic waste treatment system is also proposed, comprising: a box body, the box body comprising: a feed door at the upper end, a discharge door at the lower end, and an isolation door located in the middle between the feed door and the discharge door; wherein, the feed door, the isolation door and the discharge door are all in a closed state, dividing the box body into a sealed upper bin and a lower bin; the feeding device comprises the following three modes: a first mode, wherein the feed door is in an open state, and the isolation door and the discharge door are in a closed state; a second mode, wherein the feed door is in a closed state, the isolation door is in an open state, and the discharge door is in a closed state; a third mode, wherein the feed door and the isolation door are in a closed state, and the discharge door is in an open state.

According to an embodiment of the present invention, a feeding method for a cracking gasification furnace of a domestic waste treatment system is also proposed, which includes: providing a feeding box body, the box body including: a feeding door at the upper end, a discharge door at the lower end, and an isolation door located in the middle between the feeding door and the discharge door; wherein the feeding door, the isolation door and the discharge door are simultaneously in a closed state to divide the box body into a sealed upper silo and a lower silo; opening the feeding door and closing the isolation door to seal the lower silo, allowing the material to enter the upper silo through the feeding door, and closing the feeding door after the feeding is completed; opening the isolation door to allow the material in the upper silo to enter the lower silo, and closing the isolation door to seal the upper silo after the feeding is completed; opening the discharge door to allow the material to enter the cracking gasification furnace.

According to the technical solution of the present invention, by setting up a complete domestic waste treatment system, including: a pretreatment device, a cracking device, a cracking gas purification device and a slag sorting device, domestic waste can be completely cracked, and the final products can be reused as resources, which greatly increases the resource utilization rate; and the final products also include small molecular combustible gases that can be used instead of natural gas, which greatly increases the energy utilization efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

FIG1 is a schematic diagram of a domestic waste treatment system according to an embodiment of the present invention;

FIG2 is a schematic diagram of the overall structure of a vertical feeder according to one embodiment of the present invention;

FIG3 is a schematic structural diagram of a discharge door according to an embodiment of the present invention;

FIG4 is a schematic structural diagram of a discharge door according to another embodiment of the present invention;

FIG5 is a schematic structural diagram of an isolation door according to an embodiment of the present invention;

FIG6 is a schematic structural diagram of the U-shaped sealing groove on the edge of the side door in FIG5 ;

7 is a schematic structural diagram of a horizontal feeder according to yet another embodiment of the present invention;

FIG8 is a schematic structural diagram of a propeller according to yet another embodiment of the present invention;

FIG9 is a flow chart of a method for treating domestic waste according to an embodiment of the present invention;

FIG10 is a flow chart of a feeding method for a cracking gasifier according to an embodiment of the present invention.

DETAILED DESCRIPTION

To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

The technical solutions provided by various embodiments of the present invention are described in detail below with reference to the accompanying drawings.

Existing waste incineration or pyrolysis systems typically pre-process domestic waste. Specifically, the waste is first dehydrated and dried, then sorted to remove soil and metal materials. The sorted waste is then crushed, heated, and extruded to form fine particles suitable for use with conventional screw feeders. However, processing the waste into fine particles is time-consuming, labor-intensive, and requires additional equipment, significantly increasing the time and financial costs of waste treatment.

Pre-treated domestic waste is fed into the cracking furnace via a screw feeder, where it is cracked to produce cracking gas and slag. Currently, projects using cracking equipment to treat domestic waste or other combustible waste typically pass the resulting cracking gas directly into a secondary combustion chamber, where it burns to generate heat, which in turn heats a liquid to produce steam. This steam can drive a steam turbine, which in turn drives a generator set to generate electricity; alternatively, the steam can be used directly for heating. These methods all involve energy conversion and utilization, resulting in high energy loss and low efficiency.

Direct combustion of pyrolysis gas also produces flue gas, which requires purification before discharge. However, the purification process produces hazardous waste such as fly ash, which can only be solidified and landfilled. Furthermore, the slag produced by pyrolysis contains mixed metals, incompletely cracked organic matter, and ash. Existing technologies do not separate and recycle these slag for resource utilization, instead solidifying them as waste and landfilling them directly. Solidification and landfilling are expensive, increasing waste disposal costs.

In order to solve the above problems, a domestic waste treatment system is provided according to an embodiment of the present invention. Referring to Figure 1, the domestic waste treatment system includes: a pretreatment device 10, a cracking device 20, a cracking gas purification device 30 and a slag sorting device 40. The domestic waste treatment system can finally decompose domestic waste into small molecular combustible gas and slag ash. Not only is the cracking rate high, the calorific value of the generated small molecular combustible gas is about 1100 kcal/cubic meter. After combustion, it mainly produces carbon dioxide and water, and no tail gas purification treatment is required. It can be used directly instead of natural gas or directly drive a gas generator set to generate electricity, thereby reducing one heat exchange, not only improving thermal efficiency, but also improving energy utilization; the generated slag ash can also be used as building materials or landfill covering materials, increasing resource utilization and reducing land resource waste caused by landfill.

In some areas, the moisture content of domestic garbage or kitchen waste can be as high as about 60%, and the calorific value is about 1,700 kcal per kilogram. Excessive moisture content will not only cause garbage to stick to each other, making it difficult to sort out inorganic debris from domestic garbage, but will also reduce the calorific value of the garbage and reduce the cracking efficiency. The pretreatment device 10 can be used to implement pretreatment operations such as dehydration, drying, sorting and crushing of domestic garbage. Specifically, the domestic garbage is first sent to the crushing device to crush sealed packaging such as plastic or other packaging bags, bottles, cans, etc., to release any liquid that may be present therein. The domestic garbage is then mixed with the microbial flora and placed in a drying bin, where microorganisms are used to ferment the easily degradable organic matter in the domestic garbage to generate heat, and the water content in the garbage is partially evaporated to achieve dehydration and drying of the domestic garbage. In the embodiment of the present application, the fermentation treatment time is about 14 days, and the moisture content of the domestic garbage after fermentation treatment is 20%-40%, preferably about 30%. Inorganic impurities and metals are separated from the dehydrated and dried domestic waste. The inorganic impurities can include stones, glass, slag, etc., and the separated inorganic impurities and metals can be recovered in other ways. Because the cracking furnace in the embodiment of the present invention does not use the screw feeder commonly used in the prior art when feeding, but instead uses a more adaptable feeder, the domestic waste does not need to be finely crushed or extruded into pellets. This not only reduces the amount of equipment, saves costs, but also reduces energy consumption.

Common cracking devices currently available on the market generally consist of a cracking gasifier and a feeder positioned above or upstream of the furnace. Existing feeders fall into two general categories: The first is a screw feeder, which uses a rotating screw pusher to push waste material from a trough forward into the cracking furnace. The trough is narrowed at the furnace entrance, and the flexible compression of the waste material seals the feed opening, preventing air from entering the cracking furnace. This type of screw feeder is suitable for soft waste materials and can provide a seal, isolate air, and continuously feed the material. However, the feed speed is slow, the feeder requires continuous operation, consumes a lot of power, and is prone to jamming and shutdown when squeezed by hard materials such as coal, wood, and straw. Furthermore, the screw feeder lacks the ability to create a seal through compression deformation. The other type is a feeder that can be used for hard materials, including rotary feeders, coal block feeders, etc. These feeders can be used for coal blocks, wood blocks, hard particles, homogeneous powder materials, etc. However, these feeders are not suitable for continuous feeding of flexible materials such as domestic waste, foam plastic waste, and waste textiles. They are prone to clogging, low efficiency, and poor sealing effect.

Therefore, an embodiment of the present invention provides a cracking device 20 comprising: a hydraulic grab, a feeder, and a cracking gasification furnace. A vertical cracking furnace can be used as the cracking gasification furnace. The advantages of a vertical cracking furnace include: 1. the furnace temperature can be raised to above 800°C, meeting the requirements for high-temperature cracking; 2. the ability to perform cracking operations continuously for 24 hours; 3. a large processing capacity; 4. relatively low energy consumption, resulting in a high cost-effectiveness; and 5. excellent sealing performance, capable of maintaining a sealed state during continuous operation to prevent cracking gas from overflowing the cracking furnace. The vertical cracking furnace may include multiple feed ports, which may be located at the center of the furnace roof or above the sidewalls of the furnace roof. The feeder is located at the feed port of the vertical cracking furnace. The hydraulic grab is used to grab pretreated domestic waste and place it into the feeder. The feeder completes the process of feeding the vertical cracking furnace in a sealed state. The vertical cracking furnace cracks the domestic waste to produce cracking gas and slag. Furthermore, in order to reduce slag agglomeration, the temperature of the vertical cracking furnace can be set to 800-900℃, so that the temperature inside the furnace is lower than the temperature of slag agglomeration, greatly reducing slag agglomeration; the vertical cracking furnace can be made of refractory materials and thermal insulation materials, which not only reduces the problem of slag adhering to the furnace wall, but also improves the thermal efficiency of the cracking reaction. Without adding any other fuel or energy, the cracking operation can be maintained continuously and stably by relying solely on the energy of the waste material itself.

With reference to Figures 2 and 7, the feeder includes a box body 21, the upper end of the box body 21 is a material inlet, and the lower end is a material outlet. The cross-section of the box body 21 can be rectangular, but it can also be designed into other shapes according to actual needs, and the present application is not limited to this. A feed door 22 is provided at the upper end of the box body 21, a discharge door 23 is provided at the lower end of the box body 21, and an isolation door 24 is provided in the middle position or near the middle position of the box body 21. The isolation door 24 divides the box body 21 into two parts, forming an upper material bin 211 between the feed door 22 and the isolation door 24, and a lower material bin 212 between the isolation door 24 and the discharge door 23. When the feed door 22, the isolation door 24 and the discharge door 23 are all closed, the box body 21 is divided into a sealed upper material bin 211 and a lower material bin 212. The volume of the lower hopper 212 should be larger than that of the upper hopper 211 to prevent abnormal accumulation of material when entering the lower hopper 212, causing it to rise above the level of the central sliding door, potentially affecting the sealing effect of the central isolation door. A feed hopper 25 is also provided at the top of the main body 21 to facilitate feeding of material into the box. The feeders in this embodiment of the present invention include: a vertical feeder and a horizontal feeder. The cracking unit 20 can be equipped with either a vertical feeder or a horizontal feeder. The vertical feeder can be positioned above the center of the feed opening of the vertical cracking furnace to ensure uniform feeding. The number of horizontal feeders is at least two, preferably four. Accordingly, the vertical cracking furnace can also have four feed openings, evenly distributed above the four side walls of the vertical cracking furnace. The horizontal feeders can be evenly distributed around the vertical cracking furnace to achieve multi-point uniform feeding. The structural features of the vertical and horizontal feeders are described in detail below.

Continuing to refer to Figure 2, Figure 2 is a vertical feeder. In an embodiment of the present invention, the feed door 22 of the vertical feeder can be a single-sided push-pull structure design that is set horizontally or tilted downward. One side of the feed door 22 can penetrate the side wall of the box body 21 and be connected to the driving end of the power mechanism 221. The edges of the other three sides of the feed door 22 are provided with sealing strips, which can effectively seal the inlet of the box body 21 when closed. The sealing strips are formed by compacting and sealing with heat-resistant rubber strips to ensure a reliable seal between the edge of the feed door and the inner wall of the box body to prevent gas from overflowing. The power mechanism 221 is arranged on the outside of the box body 21 and is used to drive the feed door 22 to move along the side wall of the box body 21. During specific production, the power mechanism 221 can use a hydraulic cylinder, an air cylinder or an electric push rod to achieve the translation of the feed door 22. After the feed door 22 is opened, it is convenient to feed into the upper silo. After closing, the material in the upper silo can be unloaded into the lower silo.

A discharge door 23 is provided at the lower end of the box body 21. The discharge door 23 is directly connected to the feed port of the cracking gasifier. According to the embodiment of the present application, the discharge door 23 can be implemented in a variety of ways, which are described in detail below.

With reference to Figure 3 , in some embodiments of the present application, the discharge door 23 includes two symmetrically arranged flip doors 231. The opposite closed sides of the flip doors 231 are provided with interlocking steps 232. In practice, the protrusions of the upper and lower mating steps 232 only need to extend 5 cm, which increases the sealing surface when the discharge door is closed. Two power mechanisms 233 are symmetrically fixed to the levers of the box body 21 and the discharge door shaft, which are used to drive the flip doors 231 up and down. The power mechanisms 233 can be designed with electro-hydraulic push rods, whose driving ends are connected to the levers on the flip doors 231. The expansion and contraction of the two electro-hydraulic push rods drive the opening and closing of the flip doors. The flip doors open when they flip downward and close when they flip upward. When closed, they effectively seal the lower opening of the feeder box. The opening angle of the flip doors is controlled by a controller, and material can be fed to different locations along the tilted flip doors as needed, increasing the material delivery area and achieving uniform material distribution. The lower surface of the flip door 231 is provided with a high temperature resistant layer 234. The high temperature resistant material on the bottom of the flip door faces the cracking gasification furnace and can be used in high temperature environments to block and reduce the impact of the high temperature in the furnace on the feeder.

Referring to Figure 4 , in some embodiments of the present application, the door shaft 235 of the discharge door 23 is fixedly connected to the side wall of the housing 21 using a bearing. The door shaft 235 is appropriately extended outside the housing. A lever 236 is welded to the end of the extended door shaft 235 and fixed perpendicularly to the door shaft 235. The other end of the lever is connected to an electro-hydraulic push rod via a movable joint. When the electro-hydraulic push rod extends and retracts, it drives the door shaft and the flip door to complete the flip movement. The power mechanism 233 in this embodiment can use a hydraulic cylinder, a pneumatic cylinder, or an electric push rod to achieve the flip movement of the discharge door.

In addition, the discharge door 23 can also be set horizontally or with the open end tilted downward, and the power mechanism is set on both sides of the box body to drive the discharge door to move through the side wall of the box body.

Because the discharge door faces directly into the furnace, a high-temperature-resistant layer 234 is applied to the lower surface of the discharge door 23 to enhance its high-temperature resistance. This layer is suitable for high-temperature environments and blocks and reduces the impact of the furnace's high temperatures on the feeder. Refractory sealing strips are also provided on the edges of the other three sides of the discharge door 23, ensuring a tight seal with the inner wall of the main body 21. The high-temperature-resistant layer is made of an inorganic, high-temperature-resistant material.

With reference to Figures 2 and 5 , the isolation door 24 can be a double-sided push-pull structure, with two side doors 241 of the isolation door 24 arranged horizontally and side by side. Tracks that match the movement of the side doors 241 are provided on the opposite side walls of the box body 1. A power mechanism 242 is provided on the outside of the box body 21 to drive the two side doors 241 to move horizontally relative to each other. The power mechanism 242 can be a hydraulic cylinder, a pneumatic cylinder, or an electric push rod to open and close the biparting doors.

With reference to Figure 6 , the isolation door 4 features a mortise and tenon structure 243. One side door 241 has a U-shaped sealing groove 244 on its edge, while the other side door 241 has a tenon that fits within the U-shaped sealing groove 244. This structure ensures a tight seal when the bi-directional doors are closed. When closed, the isolation door 24 seals and separates the upper and lower hoppers 211 and 212 within the housing.

It should be noted that the power mechanism 221, the power mechanism 233, and the power mechanism 242 are all connected to a controller for controlling the start and stop sequence of the power mechanisms 221, 233, and 242. When the upper, middle, and lower doors are simultaneously closed, the feeder forms two sealed bins: an upper bin and a lower bin.

According to an embodiment of the present application, the lower part of the side wall of the box body 21 is a double-layer structure, and there is cooling water between the two layers, that is, the lower part of the side wall of the box body 21 has a water jacket structure. The water jacket structure has a cooling function, and the circulating water absorbs the heat emitted from the lower part of the box body, thereby preventing the lower part of the box body from being too hot when the feeding device is working, ensuring that the box body and the door shaft rotation structure are not deformed, and making the feeding device more stable and safe to complete the feeding work. At the same time, an insulation layer is provided at the bottom of the door to reduce the deformation of the flip door panel due to heat. This structure greatly reduces the deformation effect of temperature on the feeder, ensuring that the feeder can still operate normally and stably and maintain a sealed state in a high temperature environment. In addition, the heat absorbed by the circulating water can form water vapor, which can be used for production to complete the waste heat utilization.

Referring to FIG7 , FIG7 is a schematic diagram of the structure of a horizontal feeder. The feed door 22 of the horizontal feeder can be a single-sided push-pull structure designed to be set horizontally or tilted downwards and driven by a power mechanism (not shown in the figure). Specifically, in the embodiment of the present application, it is a single-sided push-pull door structure set horizontally; the isolation door 24 of the horizontal feeder can be a double-sided push-pull structure designed to be set horizontally or tilted downwards and driven by a power mechanism (not shown in the figure). Specifically, in the embodiment of the present application, it is a double-sided push-pull door structure set downwards. In other words, the structure of the feed door 22 and isolation door 24 of the horizontal feeder is the same as that of the feed door 22 and isolation door 24 of the vertical feeder, and will not be repeated here. Only the parts that are different from the structure of the vertical feeder are described below.

Continuing to refer to Figure 7, the horizontal feeder also includes a discharge door 23 and a propeller 26 arranged at the lower end of the box body 21, wherein the discharge door 23 is arranged on one side of the lower bin 212 in the vertical direction, and the propeller 26 is arranged on the other side of the lower bin 212 opposite to the discharge door 23. The propeller 26 can move horizontally toward or away from the discharge door 23, and the discharge door 23 can be opened or closed. The propeller 26 and the discharge door 23 cooperate to move to push the domestic waste in the lower bin 212 into the cracking gasification furnace.

In the embodiment of the present application, the discharge bin 212 of the horizontal feeder includes a first space and a second space having a length greater than the first space, that is, the second space protrudes from the first space on both opposite sides along the length direction to facilitate the arrangement of the pusher 26 and the discharge door 23. The discharge door 23 is a single-sided push-pull structure designed in the vertical direction. One side of the discharge door 23 can penetrate the side wall of the discharge bin 212 and be connected to the driving end of the power mechanism (not shown in the figure). The power mechanism can drive the discharge door 23 to open or close in the vertical direction. The edges of the other three sides of the discharge door 23 are provided with sealing strips, which can effectively seal the discharge port of the box body 21 when closed. The sealing strips are formed by compacting and sealing with heat-resistant rubber strips to ensure a reliable seal between the edge of the feed door and the inner wall of the box body. During specific production, the power mechanism can use a hydraulic cylinder, an air cylinder or an electric push rod to realize the translation of the discharge door 23. After the discharge door 23 is opened, the propeller 26 starts to work, pushing the material falling from the upper hopper 211 into the lower hopper 212 toward the discharge door 23 and falling into the cracking gasification furnace through the discharge door 23.

With reference to Figure 8 , the pusher 26 includes a front end for pushing materials, a rear end fixedly connected to the side wall of the lower hopper 212, and a telescopic portion located behind the front and rear ends for controlling the horizontal movement of the pusher 26. The front end of the pusher 26 may be trapezoidal in shape. To prevent materials from becoming stuck in the space above the pusher 26, the height of the pusher 26 may be slightly less than the height of the second space. Furthermore, to prevent materials from remaining in the lower hopper 212, the pusher 26 may protrude beyond the side wall edge of the lower hopper 212 after fully moving toward the discharge door 23.

1 , the domestic waste is cracked by the cracking device 20 to generate cracking gas and slag, wherein the cracking gas is discharged into the cracking gas purification device 30 , and the slag is transported to the slag sorting device 40 .

The cracking gas obtained by cracking domestic waste specifically includes: pollutants containing sulfur or chlorine elements, various other harmful substances, large molecular organic matter and small molecular combustible gases. Small molecular combustible gases include: carbon monoxide, hydrogen, methane and small molecular hydrocarbons and other gases. Among them, small molecular hydrocarbons specifically include: olefin compounds or alkyne compounds, etc. Since the combustion of small molecular combustible gases only produces carbon dioxide and water, small molecular combustible gases are also called clean combustible gases. Since pollutants may be produced after the combustion of large molecular organic matter, the flue gas needs to be purified before it can be discharged. Therefore, the large molecular organic matter in the cracking gas needs to be separated, collected and sent back to the cracking gasification furnace for secondary cracking until it becomes a small molecular combustible gas. In the embodiment of the present application, the large molecular organic matter is a compound with a molecular weight greater than 200Da or a carbon atom number greater than 6. The cracked gas purification device 30 can be used to remove pollutants and separate large-molecule organic matter from small-molecule combustible gases. Specifically, the cracked gas purification device 30 includes a harmful element absorption structure, a spray water washing structure, and an air cooling structure. The harmful element absorption structure can be a turbulent bed reactor or other device, and the spray water washing structure can be a spray tower. The generated cracked gas is passed into the turbulent bed reactor, where an alkaline solution such as calcium hydroxide or sodium carbonate acts as an absorbent to remove chlorine- and sulfur-containing compounds from the cracked gas. Other harmful substances, including nitrides or heavy metal aerosols, can also be removed through catalytic reduction reactions or ceramic/metal filters. The gas, free of chlorine- and sulfur-containing compounds, and other harmful substances, is passed into the spray tower, where the gas temperature is lowered through spray water washing. Because the boiling point of large-molecule organic matter is much higher than that of small-molecule combustible gases, the lowered temperature causes the large-molecule organic matter to change its physical form, from gas to liquid, solid-liquid mixed state, or solid, thereby separating it from the small-molecule combustible gases. The air-cooling system further separates residual macromolecular organic matter from the cracked gas cooled by the spray tower. The separated macromolecular organic matter is returned to the cracking gasifier for secondary cracking, breaking it down into small molecular combustible gases. The separated small molecular combustible gases can then be collected and used in an external storage device.

Although inorganic impurities and metals are sorted in the pretreatment device 10, there are still unsorted inorganic impurities and metals in the domestic waste. The unsorted inorganic impurities and metals will be discharged from the cracking gasification furnace into the slag sorting device 40 together with the slag. The slag sorting device 40 will sort the slag into metals, incompletely cracked organic matter and slag ash through operations such as screening and crushing and through instruments such as magnetic separators, jigs or eddy current separators. The separated metals can be directly sold and utilized, and the incompletely cracked organic matter (tar and charcoal, etc.) is sent back to the cracking gasification furnace for secondary cracking to continue to produce cracking gas. The slag ash is inorganic slag without impurities and can be used as building materials or landfill cover materials.

In one embodiment of the present application, a domestic waste treatment system can process 100 tons of domestic waste per day. Specifically, approximately 46 kilograms of large inorganic impurities and metals are first separated through pretreatment, of which approximately 26 kilograms of inorganic impurities are present. The pretreated waste is then fed into a cracking gasifier for cracking. The resulting cracked gas passes through a cracking gas purification device to produce approximately 1,230 cubic meters of combustible gas (small molecule combustible gas) and approximately 53 kilograms of macromolecular organic matter, such as tar. The aforementioned macromolecular organic matter is immediately returned to the cracking gasifier for further cracking. After the above process, the total amount of combustible gas obtained can reach 1,580-1,600 cubic meters. That is, the secondary cracking of 53 kilograms of macromolecular organic matter can produce an additional 350-370 cubic meters of combustible gas, significantly improving the energy and resource utilization of the domestic waste cracking products. Furthermore, testing has shown that the combustible gas produced by this domestic waste treatment system produces 0.02 nanograms of dioxin-like harmful substances after combustion, which is far less than the most stringent international standard of 0.1 nanogram.

Referring to FIG9 , according to an embodiment of the present application, a method for treating domestic waste is further provided, which includes:

S902, pre-processing the domestic waste, including dehydration, drying, sorting and crushing.

S904, cracking the domestic waste through a cracking device, wherein the cracking device includes: a cracking gasifier and a feeder arranged above the cracking gasifier, the feeder feeds the pre-treated domestic waste into the cracking gasifier for cracking and generating cracking gas and slag; wherein the feeder includes a box body, and the box body includes: a feed door located at the upper end, a discharge door located at the lower end, and an isolation door located in the middle between the feed door and the discharge door; wherein the feed door, the isolation door and the discharge door are all in a closed state, dividing the box body into a sealed upper silo and a lower silo.

S906, removing chlorine-containing compounds and sulfur-containing compounds from the cracked gas, and cooling the cracked gas to separate large molecular organic matter and small molecular combustible gas. The large molecular organic matter is sent back to the cracking gasifier for further cracking, and the small molecular combustible gas is collected in an external storage device.

S908, sorting the slag into metal, incompletely cracked organic matter and slag ash, and sending the incompletely cracked organic matter back to the cracking gasifier for further cracking.

Referring to FIG10 , according to an embodiment of the present application, a feeding method for a cracking gasifier is further provided, which includes:

S1002, provide a feed box body, the box body comprising: a feed door at the upper end, a discharge door at the lower end, and an isolation door located in the middle between the feed door and the discharge door; wherein, when the feed door, the isolation door and the discharge door are all in the closed state, the box body is divided into a sealed upper bin and a lower bin.

That is to say, the pyrolysis gasification furnace comprises three doors from top to bottom, namely: a feed door, an isolation door and a discharge door, and these three doors separate the main body of the box into an upper silo and a lower silo.

S1004, open the feed door and close the isolation door to seal the lower silo, allowing the material to enter the upper silo through the feed door, and close the feed door after the feeding is completed.

In the first mode, the upper bin is opened and the lower bin is closed.

S1006, open the isolation door to allow the material in the upper silo to enter the lower silo, and close the isolation door to seal the upper silo after the feeding is completed.

S1008, opening the discharge door to allow the material to enter the cracking gasification furnace.

The working process of the domestic waste treatment system of the present invention is as follows:

The domestic waste is crushed and mixed with microbial flora and then placed in a drying bin for dehydration for 14 days. After 14 days, the dehydrated domestic waste is sorted to remove obvious or large inorganic impurities and metals.

The crushed domestic waste is grabbed by a hydraulic grab and fed into the feed hopper 25 of the feeder. The feeder feeds the domestic waste into the cracking gasification furnace in a sealed state and cracks it to produce cracking gas and slag.

The cracking gas purification device 30 separates large molecular organic matter and small molecular combustible gas, wherein the large molecular organic matter is sent back to the cracking gasifier for secondary cracking, and the small molecular combustible gas is collected and used.

The slag sorting device 40 sorts metals, incompletely cracked organic matter and slag ash. The sorted metals can be sold directly, the incompletely cracked organic matter is sent back to the cracking gasifier for secondary cracking, and the slag ash can be recycled.

Specifically, the feeder includes a vertical feeder and a horizontal feeder. The working process of the vertical feeder is as follows:

The controller sends an opening command to the power mechanism 221 to drive the feed door 22 to open, and simultaneously sends a closing command to the power mechanism 242 and the power mechanism 233 to drive the isolation door 24 and the discharge door 23 to close. The feeder is in the first mode, and the feeder can be fed into the upper bin 211 of the feeder through the feed hopper 25;

After the upper bin 211 is full of material, the controller sends a closing command to the power mechanism 221, and the feed door 22 closes. Then, the controller sends an opening command to the power mechanism 242, and the isolation door 24 opens. The feeder is in the second mode, and the material in the upper bin 211 falls into the lower bin 212.

After the material falls into the lower hopper 212, the controller sends a closing command to the power mechanism 242, and the middle isolation door 24 closes; then it sends an opening command to the power mechanism 233, opens the discharge door 23, and the feeder is in the third mode and completes feeding into the furnace body.

As can be seen from the above, when feeding, the isolation doors 24 on both sides of the middle of the box body 21 and the bottom discharge door 23 are completely closed to form a seal, preventing air from entering the cracking gasification furnace. Then, the top feed door 22 is opened and the garbage material is placed in the upper hopper 211. The top feed door 22 is closed, and the upper hopper 211 is in a sealed state. The openings at the upper and lower ends of the box body 21 are both closed. Subsequently, the isolation door 24 in the middle is opened, and the garbage material enters the lower hopper 212 under the action of gravity. The isolation door 24 in the middle is then closed. At this time, both the upper and lower hoppers are sealed at the same time. The upper opening of the upper hopper 211 can continue to feed, and the lower opening of the lower hopper 212 can feed into the furnace, thereby achieving the functions of sealing, preventing air from entering the furnace, and continuous feeding.

During unloading, the bottom discharge door 23 is opened, and the material enters the pyrolysis gasifier under the action of gravity. After that, the discharge door 23 is closed, and the lower hopper 212 is resealed. During the unloading process, a controller controls the opening and closing sequence and status of the discharge doors 23 on both sides, changing the amount of material distributed within the furnace: when both discharge doors 23 are opened simultaneously, the waste material falls directly below the feeder; however, when only the left discharge door 23 is opened, the amount of material distributed to the left increases due to gravity and inertia, significantly exceeding 50% of the total material volume. Similarly, when only the right discharge door 23 is opened, the amount of material distributed to the right increases, significantly exceeding 50% of the total material volume. When the discharge doors 23 are fully opened, all the material enters the pyrolysis gasifier; when the discharge doors 23 are only partially opened, only a portion of the material can enter the pyrolysis gasifier.

The first mode, second mode and feeding process of the horizontal feeder are the same as those of the vertical feeder, so they will not be described here. The following only describes the working processes that are different between the horizontal feeder and the vertical feeder:

After the material falls into the lower hopper 212, the controller sends a closing command to the power mechanism of the controlled isolation door 24, and the middle isolation door 24 closes; then it sends an opening command to the power mechanism and propeller 26 that control the discharge door 23. After the discharge door 23 is opened, the propeller 26 begins to reciprocate. The feeder is in the third mode, and the propeller 26 pushes the material that has fallen into the lower hopper 212 into the cracking gasifier through the discharge door 23. During the reciprocating push of the propeller 26, the garbage falls one after another, thereby effectively dispersing the material, increasing the gaps between the garbage blocks, and greatly improving the efficiency of the subsequent cracking process. Since the horizontal feeders in the embodiment of the present application are evenly arranged above the four side walls of the cracking gasifier, each horizontal feeder completes the uniform distribution of 25% of the cross-sectional area of the cracking gasifier, effectively solving the problem of uneven feeding and improving the cracking efficiency.

According to the embodiment of the present application, the feed door 22 at the top of the feeder housing can effectively seal the housing inlet when closed. The symmetrical isolation doors 24 on both sides of the middle of the housing 21 can effectively seal the middle and lower parts of the housing when closed and the top feed door is open. The discharge door at the bottom of the feeder housing can effectively seal the bottom of the housing when sealed closed. By coordinating the opening or closing of the three doors in the housing, the continuous feeding function under sealed conditions can be reliably achieved. Since each door is opened and closed in a few seconds, no continuous power is required. Therefore, the overall energy consumption for completing the same amount of feeding is much lower than that of a screw feeder that needs to operate continuously, and the energy saving effect is obvious.

The differences between the feeder of the present invention and the existing feeder are shown in the following table:

The feeder in this invention features a scientific and rational design, a simple structure, stable performance, and low energy consumption. It is suitable for handling hard and soft garbage of various shapes and sizes, as well as combustible solid waste, and provides continuous feeding while maintaining a sealed and airtight seal. This provides a cost-effective, reliable, and energy-efficient supporting device for the new technology of treating domestic waste with pyrolysis gasification equipment. Specific advantages are as follows:

1. It can meet the feeding function of different hard and soft garbage materials.

2. Able to meet the feeding requirements of large-volume materials.

For example, if discarded packaging foam blocks, discarded plastic nets, and large sponge blocks are crushed into small pieces, the cost would be significantly increased, making the cost more than worthwhile. However, these materials shrink immediately upon exposure to heat. Once the entire block enters the cracking gasifier, it shrinks dramatically upon exposure to heat, reducing its volume to a negligible level within a short period of time. Therefore, the feeder of the present invention is fully capable of feeding these materials into the cracking gasifier, utilizing the heat within the furnace to quickly and efficiently process this type of waste without the need for crushing, significantly reducing the energy consumption required for crushing, logistics, and other operating costs.

3. Gravity feeding. The feeder is mounted on the top of the furnace. Whether feeding horizontally or vertically, gravity allows the material to fall naturally into the furnace, resulting in a fast feeding speed and no need for additional power to push the material. Furthermore, the feeder's discharge door seals securely when closed, significantly reducing power consumption for the same feeding volume, resulting in significant energy savings.

4. Increase the feeding area. By flipping the discharge door at the bottom of the vertical feeder and opening it separately, the material can be sent to different parts, or by setting up horizontal feeders at multiple points, the material can be evenly fed into the cracking gasification furnace. The area for feeding the material into the furnace is increased, which is beneficial to the uniform distribution of the material in the furnace.

5. Reliable sealing. The feeder is sealed through the door structure of each part. The door is opened and closed by the equipment controller. It is automated and stable and reliable. It does not need to rely on material extrusion sealing (extrusion sealing may be unstable due to different materials) and has good sealing performance.

The present invention provides a complete domestic waste treatment system that completely pyrolyzes domestic waste and recycles the resulting pyrolysis products, effectively improving the utilization rate of energy and resources generated by pyrolysis. Specific advantages are as follows:

1. By setting up horizontal feeders or vertical feeders suitable for various material forms and sizes, the cost of further crushing and granulation of materials in pretreatment is reduced.

2. Uniform feeding is achieved through multi-condition control, including: placing the feeder above the cracking furnace, allowing the material to fall vertically into the cracking furnace. The falling impact increases the dispersion of the material and the gaps between the materials; the horizontal feeder distributes the material at multiple points, and the vertical feeder controls the number and/or angle of opening of the discharge door. Due to the increased dispersion of the material, the particle size of the material has little effect on the cracking efficiency, thereby also reducing the cost of further crushing and granulation of the material during pretreatment.

3. Multi-condition control reduces slag agglomeration, including: sorting inorganic slag from domestic waste through pretreatment in the early stage; controlling the furnace temperature at 800-900℃ during cracking, which not only meets the cracking needs but also does not reach the temperature required for slag agglomeration (greater than 900℃); sorting the slag in the later stage, adding incompletely burned charcoal and other organic matter to the material for secondary cracking, which not only increases the calorific value but also makes full use of the material.

4. The pyrolysis gasification furnace uses refractory materials and thermal insulation materials to reduce heat loss. Without adding any other fuel or energy, it relies solely on the energy of the waste material itself to maintain continuous and stable pyrolysis operation.

5. Multiple measures are taken to improve the overall efficiency of the waste treatment system, including: increasing the calorific value of materials through drying and dehydration; sorting materials to reduce the content of inorganic slag and metals in the waste entering the furnace, thereby reducing cracking heat loss; evenly distributing materials in the cracking gasification furnace and increasing the gaps between materials to improve cracking efficiency; and using thermal insulation and refractory materials in the cracking gasification furnace to further reduce heat loss.

6. The complete resource utilization of domestic waste is realized. Not only can all products be reused, but the products also include small molecular combustible gases that can replace natural gas, thereby improving the utilization rate of energy and resources.

Although the present disclosure has been described in detail with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the embodiments. Therefore, the present disclosure is intended to cover modifications and variations of the present disclosure, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present disclosure shall be included within the scope of the claims of the present disclosure and their equivalents.

In addition, the features disclosed in the above description or claims or drawings, in their specific forms or according to the methods or processes for performing the disclosed functions or obtaining the disclosed results, can be used alone or in any combination of these features to implement the present invention in their different forms. In particular, one or more features of any embodiment described herein can be combined with one or more features of any other embodiment described herein.

Protection may also be sought for any features disclosed in any one or more of the publications cited in conjunction with the present disclosure and/or incorporated by reference.

Claims (20)

A domestic waste treatment system, comprising: A pre-treatment device, wherein the pre-treatment device pre-treats the domestic waste, and the pre-treatment includes: dehydration, drying, sorting and crushing; A cracking device, comprising: a cracking gasifier and a feeder disposed above the cracking gasifier, wherein the feeder feeds pretreated domestic waste into the cracking gasifier for cracking and produces cracking gas and slag; wherein the feeder comprises a box body, wherein the box body comprises: a feed door at an upper end, a discharge door at a lower end, and an isolation door located in the middle between the feed door and the discharge door; wherein, when the feed door, the isolation door, and the discharge door are simultaneously closed, the box body is divided into a sealed upper silo and a lower silo; a cracked gas purification device, which removes chlorine-containing compounds and sulfur-containing compounds from the cracked gas and cools the cracked gas to separate large molecular organic matter and small molecular combustible gas. The large molecular organic matter is sent back to the cracking gasifier for further cracking, and the small molecular combustible gas is collected in an external storage device; A slag sorting device is used to sort the slag into metal, incompletely cracked organic matter and slag ash, and to return the incompletely cracked organic matter to the cracking gasifier for further cracking. The domestic waste treatment system according to claim 1 is characterized in that the cracked gas purification device further includes a spray water washing structure, which reduces the temperature of the cracked gas and changes the macromolecular organic matter from a gaseous state to a liquid state, a solid-liquid mixed state, or a solid state, so as to separate the macromolecular organic matter and small molecular combustible gas in the cracked gas. The domestic waste treatment system according to claim 1 is characterized in that the feeder includes the following three modes: A first mode, wherein the feed door is in an open state, and the isolation door and the discharge door are in a closed state; A second mode, wherein the feed door is closed, the isolation door is open, and the discharge door is closed; The third mode is wherein the feed door and the isolation door are in a closed state, and the discharge door is in an open state. The domestic waste treatment system according to claim 1 is characterized in that the feeder is a vertical feeder or a horizontal feeder, the discharge door of the vertical feeder is arranged in the horizontal direction, and the discharge door of the horizontal feeder is arranged in the vertical direction. The domestic waste treatment system according to claim 4 is characterized in that the horizontal feeder also includes a propeller, which is arranged opposite to the unloading door, and the propeller pushes the domestic waste falling from the upper hopper into the lower hopper in a horizontal direction, so that the domestic waste falls into the cracking gasification furnace. The domestic waste treatment system according to claim 4 is characterized in that at least two of the horizontal feeders are evenly arranged above the feed inlet of the side wall of the pyrolysis gasification furnace. The domestic waste treatment system according to claim 4 is characterized in that the vertical feeder is arranged above the center of the feed inlet of the pyrolysis gasification furnace. The domestic waste treatment system according to claim 1 is characterized in that the feed door is a single-sided push-pull structure with the open end tilted downward and arranged horizontally. The domestic waste treatment system according to claim 1 is characterized in that the volume of the lower silo is greater than the volume of the upper silo. The domestic waste treatment system according to claim 1 is characterized in that the small molecule combustible gas includes: carbon monoxide, hydrogen, methane and small molecule hydrocarbons. A method for treating domestic waste, comprising: Pre-processing domestic waste includes: dehydration, drying, sorting and crushing; The domestic waste is cracked by a cracking device, wherein the cracking device includes: a cracking gasifier and a feeder disposed above the cracking gasifier, wherein the feeder feeds pre-treated domestic waste into the cracking gasifier for cracking and producing cracking gas and slag; wherein the feeder includes a box body, wherein the box body includes: a feed door at an upper end, a discharge door at a lower end, and an isolation door located in the middle between the feed door and the discharge door; wherein the feed door, the isolation door, and the discharge door are simultaneously closed, the box body is divided into a sealed upper silo and a lower silo; Removing chlorine-containing compounds and sulfur-containing compounds from the cracked gas, and cooling the cracked gas to separate macromolecular organic matter and small molecular combustible gas. The macromolecular organic matter is sent back to the cracking gasifier for further cracking, and the small molecular combustible gas is collected in an external storage device. The slag is sorted into metal, incompletely cracked organic matter and slag ash, and the incompletely cracked organic matter is sent back to the cracking gasifier for further cracking. The method for treating domestic waste according to claim 11 is characterized in that the cracked gas purification device further includes a spray water washing structure, which reduces the temperature of the cracked gas, causing the macromolecular organic matter to change from a gaseous state to a liquid state, a solid-liquid mixed state, or a solid state, so as to separate the macromolecular organic matter and small molecular combustible gas in the cracked gas. The method for treating domestic waste according to claim 11 is characterized in that the feeder includes the following three modes: A first mode, wherein the feed door is in an open state, and the isolation door and the discharge door are in a closed state; A second mode, wherein the feed door is closed, the isolation door is open, and the discharge door is closed; The third mode is wherein the feed door and the isolation door are in a closed state, and the discharge door is in an open state. The method for treating domestic waste according to claim 11 is characterized in that the feeder is a vertical feeder or a horizontal feeder, the discharge door of the vertical feeder is arranged in the horizontal direction, and the discharge door of the horizontal feeder is arranged in the vertical direction. The method for treating domestic waste according to claim 14 is characterized in that the horizontal feeder further includes a propeller, which is arranged opposite to the unloading door, and the propeller pushes the domestic waste falling from the upper hopper into the lower hopper in a horizontal direction, so that the domestic waste falls into the pyrolysis gasification furnace. The method for treating domestic waste according to claim 14 is characterized in that at least two of the horizontal feeders are evenly arranged above the feed inlet of the side wall of the pyrolysis gasification furnace. The method for treating domestic waste according to claim 14, wherein the vertical feeder is arranged above the center of the feed port of the pyrolysis gasification furnace. The method for treating domestic waste according to claim 11 is characterized in that the feed door is a single-sided push-pull structure with the open end tilted downward and arranged horizontally. A feeder for a cracking gasifier in a domestic waste treatment system, characterized by comprising: The box body comprises: a feed door at the upper end, a discharge door at the lower end, and an isolation door located in the middle between the feed door and the discharge door; wherein, when the feed door, the isolation door, and the discharge door are simultaneously closed, the box body is divided into a sealed upper silo and a lower silo; The feeding device includes the following three modes: A first mode, wherein the feed door is in an open state, and the isolation door and the discharge door are in a closed state; A second mode, wherein the feed door is closed, the isolation door is open, and the discharge door is closed; The third mode is wherein the feed door and the isolation door are in a closed state, and the discharge door is in an open state. A feeding method for a cracking gasifier in a domestic waste treatment system, characterized by comprising: A feeding box body is provided, the box body comprising: a feeding door at the upper end, a discharge door at the lower end, and an isolation door located in the middle between the feeding door and the discharge door; wherein the feeding door, the isolation door, and the discharge door are simultaneously closed, dividing the box body into a sealed upper bin and a lower bin; Open the feed door and close the isolation door to seal the lower silo, allowing the material to enter the upper silo through the feed door, and close the feed door after the feeding is completed; Open the isolation door to allow the material in the upper hopper to enter the lower hopper, and close the isolation door to seal the upper hopper after the feeding is completed; Open the discharge door to allow the materials to enter the cracking gasifier.