Multi-hearth furnace combination of forward and reverse push grading gasification combustion furnace

Abstract

The present application relates to solid waste incineration processing technical field, specifically disclose a multi-chamber combination of forward and reverse push grading gasification combustion furnace, including drying pyrolysis chamber, gasification combustion chamber and pyrolysis gasification chamber, pyrolysis gasification chamber and drying pyrolysis chamber and gasification combustion chamber are communicated;Gasification combustion chamber is equipped with high temperature flue gas outlet, and the high temperature flue gas outlet is communicated with the waste heat utilization chamber;Drying pyrolysis chamber is equipped with drying pyrolysis section grate group, gasification combustion chamber is equipped with gasification section grate group and combustion and incineration section grate group, and the gasification section grate group and combustion and incineration section grate group form V type, the input end of the gasification section grate group is located below the outlet of the pyrolysis gasification chamber, the gasification section grate group adopts reverse push structure, and the drying pyrolysis section grate group and combustion and incineration section grate group adopt forward push structure. Using the present application to process garbage, garbage material is transported smoothly in the furnace, and the efficiency is high, the agitation mixing is sufficient, the gasification combustion efficiency is high, and the whole combustion furnace is simple to operate, the structure is compact, and the construction and use maintenance cost is lower.

Description

Technical Field

[0001] This invention relates to the field of solid waste incineration technology, specifically to a multi-furnace forward and reverse combined staged gasification combustion furnace. Background Technology

[0002] Existing waste treatment technologies mainly include incineration, sanitary landfill, and composting. Among conventional waste treatment technologies, incineration is widely used due to its advantages such as significant volume reduction, thorough detoxification, small land occupation, utilization of waste heat energy, and less secondary pollution.

[0003] The most common existing incinerators include fluidized bed incinerators, mechanical grate incinerators, and fixed bed combustion furnaces. Fluidized bed incineration technology is one of the most mature waste incineration technologies in the world. However, fluidized bed incinerators have high requirements for waste pretreatment. Currently, the standardization of household waste sorting and collection in my country is poor, and waste without pretreatment often fails to meet size requirements. Furthermore, the composition of waste in my country is complex, its sources are diverse, and it often has high moisture content and low calorific value, leading to unstable operating conditions and a high failure rate for fluidized bed incinerators. Mechanical grate incinerators have advantages such as a long history of application, mature technology, no need for waste pretreatment, low failure rate, long annual operating time, large processing capacity, stable combustion without the need for auxiliary fuel, and low fly ash production. They have extensive track records both domestically and internationally, and the vast majority of the global waste incineration industry uses this technology, especially in the field of waste-to-energy incineration in large and medium-sized cities in my country.

[0004] Given the complex composition, diverse sources, and wide distribution of domestic waste in my country's rural areas, with significant fluctuations in quantity and composition due to seasonal and regional variations, particularly its multi-scale nature, low calorific value, and high moisture content, fixed-bed pyrolysis gasification combustion furnaces have been developed both domestically and internationally. Among these, the vertical rotary gasification combustion furnace, based on fixed-bed pyrolysis gasification technology, boasts advantages such as compact structure, convenient maintenance, and simple operation, and has been widely adopted in rural areas of southern my country. However, to ensure the normal operation of the pyrolysis gasification combustion process within the fixed-bed / vertical rotary gasification combustion furnace, pretreatment processes and equipment such as sorting, crushing, magnetic separation, and drying of the waste are required, leading to substantial investment. Furthermore, the numerous procedures increase the potential for failures, consequently raising operating and maintenance costs.

[0005] Furthermore, rural waste is geographically dispersed and transported over long distances, resulting in extremely limited processing capacity for a single vertical rotary gasification combustion furnace. The thermochemical reaction space and slag discharge channel in the developed pyrolysis gasification chamber are also narrow, leading to poor agitation and mixing. With inadequate waste pretreatment, it is difficult to ensure uniform material distribution. Additionally, the physical and chemical properties of the waste vary significantly due to its different composition and origin, and coking and clumping are common occurrences within the furnace under pyrolysis gasification conditions. These multiple unfavorable factors easily lead to unstable operation of the vertical rotary gasification combustion furnace, incomplete combustion, and even serious shutdowns such as poor slag discharge and mechanical jamming.

[0006] In the prior art, in order to combine the pyrolysis and gasification of waste incineration with reducing the size and investment of incinerators, there has been extensive research in this field on incinerators and the grate systems they employ. For example, a multi-layer reciprocating gasification combustion furnace, patent publication number CN107131503A, is described. This combustion furnace consists of three overlapping grates, with connecting channels between two layers and a feeding hopper. This technology has a wide range of adaptability to raw materials used in waste treatment, and each grate layer can achieve pyrolysis and gasification combustion.

[0007] A boiler grate with energy-saving and emission-reduction functions, disclosed in patent publication number CN111473347A, includes an extrusion roller, a V-shaped plate, a wind box, a support plate, a sliding plate, and a lead screw. Coal combustion occurs on the V-shaped plate, which is oscillatingly connected to the support plate at its bottom. Limiting bodies are fixedly installed on two inclined surfaces at the bottom of the V-shaped plate. When the coal accumulated on the V-shaped plate burns, producing large, incompletely burned carbon slag particles, the sliding plate drives the extrusion roller to roll and crush the carbon slag on one inclined surface of the V-shaped plate, thus ensuring complete combustion. Simultaneously, the other inclined surface becomes more inclined, facilitating the sliding of the carbon slag and thus improving the ash discharge. This also increases the combustion rate of the carbon slag on the other inclined surface and reduces ash discharge.

[0008] The technology described in CN107131503A, when applied to the incineration of rural household waste in my country, suffers from several drawbacks. The overall process control is complex, and the multi-layered grate setup results in a large incinerator structure and substantial investment in plant and equipment. Furthermore, the waste has an extremely high moisture content (up to 50%), low calorific value, and low density, requiring a grate thickness of approximately 600mm. Continuous and active multi-dimensional agitation is also necessary to ensure thorough drying and complete combustion. In contrast, CN111473347A describes a thinner coal combustion layer, typically 100-200mm, which burns more easily without excessive agitation. However, this approach is not suitable for the incineration of rural household waste in China. Therefore, the aforementioned technology is not applicable to the needs of rural household waste treatment in my country. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the prior art and provide a miniaturized multi-furnace forward and reverse push combined staged gasification combustion furnace for the disposal of rural domestic waste. When this multi-furnace forward and reverse push combined staged gasification combustion furnace is used to process waste, the waste material is transported efficiently in the furnace, the mixing is thorough, the gasification and combustion efficiency is high, and the entire combustion furnace is simple to operate, compact in structure, and has low construction, use and maintenance costs.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] The multi-furnace forward and reverse push combined staged gasification combustion furnace includes a drying pyrolysis chamber and a gasification combustion chamber arranged vertically. A pyrolysis gasification chamber is also located between the drying pyrolysis chamber and the gasification combustion chamber. The inlet of the pyrolysis gasification chamber is connected to the outlet of the upper drying pyrolysis chamber, and the outlet of the pyrolysis gasification chamber is connected to the lower gasification combustion chamber. The gasification combustion chamber is under negative pressure and has a high-temperature flue gas outlet connected to a waste heat utilization chamber. The drying pyrolysis chamber contains a drying pyrolysis section grate assembly, and the gasification combustion chamber contains a gas... The gasification section grate group and the combustion and burnout section grate group are connected. Waste from the output end of the gasification section grate group is fed into the input end of the combustion and burnout section grate group. The gasification section grate group and the combustion and burnout section grate group form a V-shape. The input end of the gasification section grate group is located below the outlet of the pyrolysis gasification chamber. The input end of the gasification section grate group is higher than the output end of the gasification section grate group and the output end of the combustion and burnout section grate group. The gasification section grate group adopts a reverse push structure. The drying pyrolysis section grate group and the combustion and burnout section grate group both adopt a forward push structure.

[0012] Preferably, as an improvement, the angle between the overall grate surface of the gasification section grate group and the overall grate surface of the combustion section grate group is 168 degrees, the inclination angle of the overall grate surface of the gasification section grate group relative to the horizontal plane is 28 degrees, the inclination angle of a single row grate surface of the gasification section grate group relative to the horizontal plane is 44 degrees, the inclination angle of the overall grate surface of the combustion section grate group relative to the horizontal plane is 16 degrees, and the inclination angle of a single row grate surface of the combustion section grate group relative to the horizontal plane is 0 degrees.

[0013] Preferably, as an improvement, the waste heat utilization chamber surrounds the outer wall of the pyrolysis gasification chamber, and multiple baffles are provided on the flue gas flow path of the waste heat utilization chamber, with adjacent baffles staggered, so that the flue gas flow path is S-shaped.

[0014] Preferably, as an improvement, the waste heat utilization chamber has an S-shaped heat exchange tube coiled around its outdoor surface. The heat exchange tube is used to provide primary air for heating the gasification section grate assembly and the combustion section grate assembly of the gasification combustion chamber.

[0015] Preferably, as an improvement, the high-temperature flue gas is purified after passing through the waste heat utilization chamber, and the low-temperature flue gas formed after purification is sent into the drying pyrolysis chamber as needed. A temperature sensor is installed at the inlet of the low-temperature flue gas entering the drying pyrolysis chamber.

[0016] Preferably, as an improvement, it also includes a pressing block placed at the junction of the gasification section grate group and the combustion section grate group; so that the gap at the junction of the gasification section grate group and the combustion section grate group can be covered as much as possible, so that the waste can smoothly pass through the joint at the junction.

[0017] Preferably, as an improvement, the cross-section of the pressing block is trapezoidal.

[0018] Preferably, as an improvement, the gasification combustion chamber is provided with a secondary air duct, and the outlet of the secondary air duct faces upwards towards the grate assembly of the combustion and burnout section.

[0019] Preferably, as an improvement, it also includes multiple temperature sensors and pressure sensors installed in the drying pyrolysis chamber, pyrolysis gasification chamber, and gasification combustion chamber; to facilitate the detection of the temperature in each reaction section and the pressure in each chamber, and to facilitate real-time online control of temperature and pressure.

[0020] Preferably, as an improvement, the gasification combustion chamber is provided with a burner.

[0021] The technical principle of this invention is as follows: During use, waste is fed into the drying pyrolysis chamber. The waste is conveyed and agitated by the moving grate bars of the drying pyrolysis section grate assembly within the chamber. Under the influence of low-temperature flue gas and the conductive heat from the waste heat utilization chamber, it is fully dried and undergoes a localized pyrolysis reaction, releasing water vapor and generating a small amount of pyrolysis gas which simultaneously enters the waste bed in the pyrolysis gasification chamber under negative pressure. The dried waste moves from the discharge end of the drying pyrolysis section grate assembly to the pyrolysis gasification chamber, where it continues to undergo pyrolysis and gasification reactions under the radiant heat of the gasification combustion chamber furnace and the partially heated primary air, producing syngas. Simultaneously, the water vapor passing through the waste bed enhances the gasification process, further increasing syngas production. The mixture of pyrolysis and gasification waste residue and a small amount of raw waste continuously enters the gasification grate assembly with a reverse-push structure. This grate assembly pushes the waste bed upwards at an angle. Under the combined forces of gravity and the upward push, the waste bed tumbles and mixes, falling layer by layer into the combustion grate assembly, enhancing the mixing effect. The waste is better mixed and has a longer residence time during this process, allowing for greater contact between the waste and the heated primary air. Under the combined effects of radiant heat from the furnace, heat from gas-phase combustion, and the movement of the reverse and forward push grates, the waste undergoes complete gasification and combustion, turning into ash and being discharged, thus completing the incineration process. Simultaneously, the combustible gases in the flue gas are completely combusted in the gasification combustion chamber under the action of secondary air. Only then does the high-temperature flue gas enter the waste heat recovery chamber from the high-temperature flue gas outlet, and finally, after purification, it meets emission standards.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. A relatively independent 3+1 chamber (i.e., drying pyrolysis chamber, pyrolysis gasification chamber, gasification combustion chamber, and waste heat utilization chamber) with temperature and pressure sensors was designed and integrated into a single unit to ensure the feasibility of the staged gasification combustion process. The drying pyrolysis chamber ensures sufficient drying and local pyrolysis reaction. The pyrolysis gasification chamber facilitates the complete pyrolysis and gasification of waste. The gasification combustion chamber enables complete combustion of waste. The waste heat utilization chamber utilizes high-temperature flue gas to provide heat for the insulation and heating of the waste pyrolysis gasification chamber and the primary air heating. The entire system has a compact structure, low cost, is easy to programmatically control in stages and segments, is simple to operate, and requires fewer personnel.

[0024] 2. The upper drying pyrolysis chamber adopts a forward-push structure for the drying pyrolysis section grate assembly, which helps to reduce the furnace height, ensures fast conveying and high processing efficiency, and has low requirements for waste size. Furthermore, the high-temperature flue gas discharged from the gasification combustion chamber, after waste heat recovery and subsequent desulfurization and dust removal purification treatment, forms low-temperature flue gas that is introduced into the drying pyrolysis chamber as needed, realizing energy reuse. A temperature sensor is installed at the inlet of the low-temperature flue gas into the drying pyrolysis chamber to control the gas inlet temperature and prevent excessively high temperatures that could lead to premature pyrolysis and gasification reactions.

[0025] 3. A pyrolysis gasification chamber is provided to facilitate the full pyrolysis and gasification of complex, high-moisture, and low-calorific-value township waste. This allows the large molecules of organic components in the waste to break down and be converted into small-molecule combustible gases such as combustion gas and combustion oil, which is beneficial for subsequent gasification and combustion and promotes the harmlessness and volume reduction of all gaseous and solid materials in the furnace.

[0026] 4. The pyrolysis gasification chamber has a reasonable spatial design, which ensures the smooth movement of waste, water vapor and combustible gas from top to bottom in the pyrolysis gasification chamber, which is conducive to the full pyrolysis gasification of waste.

[0027] 5. The outer side of the drying pyrolysis chamber is equipped with a waste heat utilization chamber through which high-temperature flue gas passes. The functions of the waste heat utilization chamber are as follows: First, to heat and keep the pyrolysis gasification chamber warm, so that the high-temperature flue gas after high-temperature combustion in the gasification combustion chamber can be reused, thereby enhancing the drying, pyrolysis and gasification effects of the pyrolysis gasification chamber; Second, to use the waste heat of the high-temperature flue gas to heat the primary air in the heat exchange tubes arranged in the wall of the waste heat utilization chamber. The heated primary air is then introduced into the gasification section grate group and the combustion and burnout section grate group, which is more conducive to the gasification and combustion reaction.

[0028] 6. This invention features multiple baffles, with adjacent baffles staggered, resulting in an S-shaped flow path for the high-temperature flue gas within the waste heat recovery chamber, thus improving waste heat recovery efficiency. Simultaneously, the baffles facilitate the collection of particulate matter in the flue gas, reducing dust emissions from the medium-temperature exhaust port of the waste heat recovery chamber and simplifying subsequent dust removal processes. Furthermore, the heat from the high-temperature dust falling into the waste heat recovery chamber is also recovered, further enhancing the heat recovery efficiency of the chamber.

[0029] 7. The lower gasification combustion chamber adopts a combination of reverse-push and forward-push grate structures. The grate structure is V-shaped, and the tilt angle design of the grate group in the gasification section and the grate group in the combustion section optimizes the stroke of the grate. This facilitates strong agitation and mixing of waste during transportation, enhances heat exchange and gasification combustion efficiency, and extends the residence time of waste. This ensures that waste with high moisture content, complex composition, and multiple scales in rural areas can be fully gasified and burned, preventing waste accumulation and clumping, incomplete gasification and combustion, or even problems such as poor slag discharge and mechanical jamming. This reduces the pretreatment required for rural waste and the maintenance costs during the use of the combustion furnace.

[0030] 8. When using this invention, the gas in the combustion furnace is under negative pressure and passes through the drying pyrolysis chamber, the pyrolysis gasification chamber, and the gasification combustion chamber before finally being sent to the waste heat utilization chamber. Throughout the process, all the water vapor generated in the drying pyrolysis chamber, as well as the pyrolysis gas and gasification synthesis gas generated in the pyrolysis gasification chamber, are discharged after entering the gasification combustion chamber. The water vapor participates in the gasification reaction as a gasifying agent at high temperature, while the combustible gas generated by pyrolysis and gasification is sent into the gasification combustion chamber for complete combustion under negative pressure. Compared with the prior art, there is no need to set up separate processes and corresponding equipment for the treatment of water vapor, flue gas, pyrolysis gas, and gasification gas, which greatly simplifies the treatment of water vapor, pyrolysis gas, and gasification gas.

[0031] 9. This invention incorporates a secondary air duct in the gasification combustion chamber. The secondary air supply provides oxygen-containing air to the high-temperature flue gas above the grate assembly in the combustion burnout section. Under the impact of the secondary air, the high-temperature flue gas forms turbulence in the upper space of the gasification combustion chamber. This ensures that the combustible gases in the flue gas have a large and prolonged contact and reaction with the oxygen-containing air, guaranteeing thorough mixing and residence of the flue gas at temperatures above 850 degrees Celsius. Simultaneously, it promotes the complete decomposition of dioxins and helps reduce the difficulty of subsequent flue gas treatment and lower the content of harmful substances in the flue gas.

[0032] 10. The burner of this invention serves two purposes: firstly, it acts as a furnace preheater, ensuring that each chamber reaches its expected performance; secondly, it serves as a furnace start-up device. When the incinerator starts up, the temperature of each chamber is not yet at the expected level, requiring the burner to be activated to provide heat, raise the temperature of each chamber, prepare for feeding, and lay the foundation for the gasification combustion process. In addition, the burner also plays a role in combustion assistance and regulation. Under extreme operating conditions, the burner is activated to provide heat, regulate, and maintain the normal operating conditions of the gasification combustion system.

[0033] 11. This invention features an integrated design that optimizes the combination of various chambers and structures, making full use of the space. It adopts a system design with an upper drying pyrolysis chamber, a lower gasification combustion chamber, and a connecting area that serves as a pyrolysis gasification chamber. This results in a lower overall height of the combustion furnace. Furthermore, the reverse-push grate structure and the forward-push grate structure within the gasification combustion chamber form a V-shape. A pressure plate is placed at the intersection of the reverse-push grate structure and the forward-push grate structure to facilitate the passage of waste. This design does not increase the floor space excessively. While improving combustion efficiency and environmental performance, it reduces the overall volume and eliminates the need for excessive investment in plant facilities and equipment, making it conducive to construction and promotion.

[0034] In summary, this invention can be widely applied to the miniaturized gasification combustion of rural domestic waste. Attached Figure Description

[0035] Figure 1 This is a structural front view of an embodiment of the present invention.

[0036] Figure 2 for Figure 1 The left view.

[0037] Figure 3 for Figure 2 AA sectional view.

[0038] Figure 4 This is a schematic diagram of the installation of the indoor spoiler for waste heat utilization in an embodiment of the present invention.

[0039] Figure 5 This is a diagram showing airflow and heat radiation in an embodiment of the present invention. Detailed Implementation

[0040] The following detailed description illustrates the specific implementation method:

[0041] The reference numerals in the accompanying drawings include: 1. Drying pyrolysis chamber; 2. Gasification combustion chamber; 3. Pyrolysis gasification chamber; 4. Hopper; 41. Discharge valve; 5. Gasification section grate assembly; 6. Combustion burnout section grate assembly; 7. Press briquette; 8. Waste heat utilization chamber; 20. High-temperature flue gas outlet; 10. Low-temperature flue gas supply duct; 30. Heat exchange tube; 81. Baffle plate; 40. Temperature sensor; 50. Pressure sensor; 60. Secondary air duct; 80. Medium-temperature flue gas outlet; 70. Ash discharge outlet.

[0042] The basic implementation examples are as follows: Figures 1 to 5 As shown, the multi-furnace forward and reverse push combined staged gasification combustion furnace includes a hopper 4, a drying pyrolysis chamber 1, and a gasification combustion chamber 2 arranged sequentially from top to bottom. A discharge valve 41 is installed at the connection between the hopper 4 and the drying pyrolysis chamber 1. In this embodiment, the discharge valve 41 is a single-line discharge valve 41. The presence of the discharge valve 41 and the hopper 4 enables the mechanical seal and material seal of the feed inlet of the drying pyrolysis chamber 1 to work simultaneously, resulting in a better sealing effect and ensuring the controllability of the atmosphere in the drying pyrolysis chamber 1.

[0043] A pyrolysis gasification chamber 3 is also provided between the drying pyrolysis chamber 1 and the gasification combustion chamber 2. The pyrolysis gasification chamber 3 has a floor area larger than 1 meter * 1 meter and a height greater than 1 meter to avoid material blockage problems caused by narrow connecting channels. The inlet of the pyrolysis gasification chamber 3 is connected to the outlet of the upper drying pyrolysis chamber 1, and the outlet of the pyrolysis gasification chamber 3 is connected to the lower gasification combustion chamber 2. Neither the drying pyrolysis chamber 1 nor the gasification combustion chamber 2 has a steam exhaust outlet. Only the gasification combustion chamber 2 has a high-temperature flue gas outlet 20, which is connected to a negative pressure unit to keep the gasification combustion chamber 2 under negative pressure.

[0044] The drying pyrolysis chamber 1 is equipped with a drying pyrolysis section grate assembly, and the gasification combustion chamber 2 is equipped with a gasification section grate assembly 5 and a combustion and burnout section grate assembly 6. The gasification section grate assembly 5 and the combustion and burnout section grate assembly 6 form a V-shape. The included angle between the overall grate surface of the gasification section grate assembly 5 and the overall grate surface of the combustion and burnout section grate assembly 6 is 168 degrees. The overall grate surface of the gasification section grate assembly 5 has an inclination angle of 28 degrees relative to the horizontal plane. The inclination angle of a single row of the gasification section grate assembly 5 relative to the horizontal plane is 44 degrees. The overall grate surface of the combustion and burnout section grate assembly 6 has an inclination angle of 16 degrees relative to the horizontal plane. The inclination angle of a single row of the combustion and burnout section grate assembly 6 relative to the horizontal plane is 0 degrees. The input end of the gasification section grate group 5 is located below the outlet of the pyrolysis gasification chamber 3. The input end of the gasification section grate group 5 is higher than the output end of the gasification section grate group 5 and the output end of the combustion and burnout section grate group 6. The gasification section grate group 5 adopts a reverse push structure, while the drying pyrolysis section grate group and the combustion and burnout section grate group 6 both adopt a forward push structure. In this embodiment, the number of fixed grate bars and movable grate bars in the combustion and burnout section grate group 6 is one more than that in the gasification section grate group 5, and the grate bars at the output end of the combustion and burnout section grate group 6 are movable grate bars.

[0045] To facilitate the faster falling of solids at the junction onto the combustion grate group 6, a transverse pressure block 7 is placed at the junction of the gasification grate group 5 and the combustion grate group 6. The cross-section of the pressure block 7 is trapezoidal.

[0046] The outer wall of the pyrolysis gasification chamber 3 is also surrounded by a waste heat utilization chamber 8, which is U-shaped and extends to the front and rear sides of the drying pyrolysis chamber 1. This allows the waste heat utilization chamber 8 to both insulate and heat the pyrolysis gasification chamber 3 while also providing some insulation for the drying pyrolysis chamber 1. The high-temperature flue gas outlet 20 of the gasification combustion chamber 2 is close to the output end of the grate group 6 in the combustion burnout section, and the high-temperature flue gas outlet 20 is connected to the waste heat utilization chamber 8. The waste heat utilization chamber 8 is equipped with a medium-temperature flue gas outlet 80. The medium-temperature flue gas discharged from the medium-temperature flue gas outlet 80 is desulfurized to form low-temperature flue gas. The low-temperature flue gas is then sent into the drying pyrolysis chamber through the low-temperature flue gas supply pipe 10. A temperature sensor 40 is installed at the inlet of the low-temperature flue gas into the drying pyrolysis chamber 1. A flow regulating valve is installed on the low-temperature flue gas supply pipe 10 to allow operators to control the flow rate of the gas required by the grate group in the drying pyrolysis section based on the temperature displayed by the temperature sensor 40, preventing excessively high temperatures and premature pyrolysis gasification reactions.

[0047] The waste heat utilization chamber 8 has an S-shaped heat exchange tube 30 coiled inside the wall. The heat exchange tube 30 is used to provide heating primary air to the gasification section grate group 5 and the combustion section grate group 6 of the gasification combustion chamber 2. In this embodiment, the waste heat utilization chamber 8 has a sandwich layer inside the wall, and the heat exchange tube 30 is placed in the sandwich layer. At the same time, in order to ensure that the heat of the heat exchange tube 30 is not easily lost, the surface of the wall of the waste heat utilization chamber 8 is covered with thermal insulation material.

[0048] To improve the waste heat recovery effect of the waste heat utilization chamber 8, multiple baffles 81 are fixed in the flue gas flow path of the waste heat utilization chamber 8. Adjacent baffles 81 are staggered, making the flue gas flow path S-shaped. The baffles 81 of the waste heat utilization chamber 8 are arranged as follows: Figure 4 As shown.

[0049] In addition, multiple temperature sensors 40 and pressure sensors 50 are installed in the drying pyrolysis chamber 1, the pyrolysis gasification chamber 3, the gasification combustion chamber 2, and the waste heat utilization chamber 8, so that the temperature of each stage of waste treatment—drying, pyrolysis, gasification, combustion, and burnout can be accurately obtained, facilitating segmented control at each stage.

[0050] A burner is installed inside the gasification combustion chamber 2. A secondary air duct 60 is installed on the gasification combustion chamber 2, located near the high-temperature flue gas outlet 20. In this embodiment, the secondary air duct 60 is located above the high-temperature flue gas outlet 20, and its outlet faces upwards towards the grate assembly 6 in the combustion and burnout section. Both the drying pyrolysis chamber 1 and the gasification combustion chamber 2 are provided with ash discharge ports 70 below the grate assembly to facilitate the cleaning of ash and slag falling from the reciprocating grate. The gasification combustion chamber 2 is provided with a slag discharge port for convenient ash discharge.

[0051] The specific implementation process is as follows:

[0052] In this embodiment, during waste processing, the waste is fed into the drying pyrolysis chamber 1. The waste is conveyed and agitated by the moving grate bars of the drying pyrolysis section grate assembly within the chamber 1. Under the influence of low-temperature flue gas and radiant heat from the waste heat utilization chamber 8, the waste is thoroughly dried and undergoes localized pyrolysis, releasing water vapor and generating a small amount of pyrolysis gas. This gas simultaneously enters the waste layer in the pyrolysis gasification chamber 3 under the action of a negative pressure compressor. The dried waste moves from the discharge end of the drying pyrolysis section grate assembly to the pyrolysis gasification chamber 3 and accumulates there. Under the influence of radiant heat from the furnace of the gasification combustion chamber 2, the heat of gas-phase combustion, and heated primary air, pyrolysis and gasification reactions continue, producing syngas. Simultaneously, the water vapor passing through this waste layer enhances the gasification process, further increasing syngas production. The mixture of pyrolysis and gasification waste residue and a small amount of raw waste continuously enters the gasification grate group 5 of the reverse-push structure. The gasification grate group 5 of the reverse-push structure pushes the material layer obliquely upward. Under the action of gravity and oblique upward push, the material layer tumbles and falls layer by layer, which enhances the mixing effect. The waste is better mixed and has a longer residence time in this process, so that the waste comes into a large amount of contact with the heated primary air. Under the action of furnace radiation heat, gas phase combustion heat, grate movement, etc., the waste undergoes a complete gasification and combustion reaction, turns into ash and is discharged from the ash discharge port, thus completing the waste incineration treatment.

[0053] During the process of drying, pyrolysis, gasification, combustion, and burnout of waste, the gasification combustion chamber 2 is under negative pressure, causing all the water vapor, pyrolysis gas, gasification gas, and high-temperature flue gas generated in the furnace to flow towards the high-temperature flue gas outlet 20. At the same time, the secondary air duct 60 sends oxygen-containing air into the gasification combustion chamber 2, reducing the flow rate of all gases towards the high-temperature flue gas outlet 20. This allows the combustible gas in the gasification combustion chamber 2 to remain sufficiently and be completely burned before entering the waste heat utilization chamber 8 from the high-temperature flue gas outlet 20 as high-temperature flue gas. Finally, after undergoing desulfurization, dust removal, and other processes for flue gas purification, the waste gas is discharged in compliance with emission standards.

[0054] This multi-chamber, combined forward and reverse push staged gasification combustion furnace treats waste with high efficiency in material conveying within the furnace, long residence time, thorough mixing, and high gasification combustion efficiency. It reduces heat loss and improves heat exchange efficiency, resulting in high heat recovery efficiency and effectively reducing pollutant emissions. Furthermore, this gasification combustion furnace allows for staged and segmented control based on temperature and pressure readings in each chamber, simplifying operation. In addition, its compact structure, small overall size, and low construction and maintenance costs make it ideal for small-scale gasification combustion of municipal solid waste in rural areas.

[0055] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A multi-furnace combined forward and reverse push staged gasification combustion furnace, comprising a drying pyrolysis chamber and a gasification combustion chamber arranged vertically, characterized in that: A pyrolysis gasification chamber is also provided between the drying pyrolysis chamber and the gasification combustion chamber. The inlet of the pyrolysis gasification chamber is connected to the outlet of the upper drying pyrolysis chamber, and the outlet of the pyrolysis gasification chamber is connected to the lower gasification combustion chamber. The gasification combustion chamber is under negative pressure and has a high-temperature flue gas outlet that is connected to the waste heat utilization chamber. The drying pyrolysis chamber is equipped with a drying pyrolysis section grate group, and the gasification combustion chamber is equipped with a gasification section grate group and a combustion burnout section grate group. The waste from the output end of the gasification section grate group is fed into the input end of the combustion burnout section grate group. The gasification section grate group and the combustion burnout section grate group form a V-shape. The input end of the gasification section grate group is located below the outlet of the pyrolysis gasification chamber. The input end of the gasification section grate group is higher than the output end of the gasification section grate group and the output end of the combustion burnout section grate group. The gasification section grate group adopts a reverse push structure, while the drying pyrolysis section grate group and the combustion burnout section grate group both adopt a forward push structure.

2. The multi-furnace forward and reverse combined staged gasification combustion furnace according to claim 1, characterized in that: The angle between the overall grate surface of the gasification section grate group and the overall grate surface of the combustion section grate group is 168 degrees. The overall grate surface of the gasification section grate group has an inclination angle of 28 degrees relative to the horizontal plane. The single-row grate surface of the gasification section grate group has an inclination angle of 44 degrees relative to the horizontal plane. The overall grate surface of the combustion section grate group has an inclination angle of 16 degrees relative to the horizontal plane. The single-row grate surface of the combustion section grate group has an inclination angle of 0 degrees relative to the horizontal plane.

3. The multi-furnace forward and reverse combined staged gasification combustion furnace according to claim 2, characterized in that: The waste heat utilization chamber surrounds the outer wall of the pyrolysis gasification chamber. Multiple baffles are provided on the flue gas flow path of the waste heat utilization chamber. Adjacent baffles are staggered, so that the flue gas flow path is S-shaped.

4. The multi-furnace forward and reverse combined staged gasification combustion furnace according to claim 2, characterized in that: The waste heat utilization chamber has S-shaped heat exchange tubes coiled around its outer surface. These heat exchange tubes are used to provide primary air for heating the gasification section grate assembly and the combustion section grate assembly in the gasification combustion chamber.

5. The multi-furnace forward and reverse combined staged gasification combustion furnace according to claim 2, characterized in that: After passing through the waste heat utilization chamber, the high-temperature flue gas is purified. The low-temperature flue gas formed after purification is sent into the drying pyrolysis chamber as needed. A temperature sensor is installed at the inlet of the low-temperature flue gas into the drying pyrolysis chamber.

6. The multi-furnace forward and reverse combined staged gasification combustion furnace according to claim 1, characterized in that: It also includes briquettes placed at the intersection of the gasification grate group and the combustion grate group.

7. The multi-furnace forward and reverse combined staged gasification combustion furnace according to claim 6, characterized in that: The cross-section of the pressing block is trapezoidal.

8. The multi-furnace forward and reverse combined staged gasification combustion furnace according to any one of claims 1-7, characterized in that: The gasification combustion chamber is equipped with a secondary air duct, and the outlet of the secondary air duct faces upwards from the grate assembly of the combustion and burnout section.

9. The multi-furnace forward and reverse combined staged gasification combustion furnace according to any one of claims 1-7, characterized in that: It also includes multiple temperature and pressure sensors installed in the drying pyrolysis chamber, pyrolysis gasification chamber, and gasification combustion chamber.

10. The multi-furnace forward and reverse combined staged gasification combustion furnace according to any one of claims 1-7, characterized in that: The gasification combustion chamber is equipped with a burner.

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