Pyrolysis gasification combustion furnace and organic solid waste combustion treatment method

Abstract

The invention discloses an organic solid waste pyrolysis gasification combustion system and method, and relates to the technical field of solid waste pyrolysis incineration equipment. A secondary combustion area, a drying area and a pyrolysis gasification area which are communicated with one another are arranged in the organic solid waste pyrolysis gasification combustion furnace body from top to bottom; arranging a dryer in a combustion furnace, and drying the wet-based organic solid waste by using heat generated by pyrolysis and gasification; a water vapor recovery pipe is arranged above an opening in the upper end of the dryer and is communicated with the outside of the furnace body; the pyrolysis gasification area is provided with a pyrolysis gasification air distribution device; a smoke outlet is formed in the side face of the secondary combustion area. Heat generated in the thermochemical conversion process is efficiently utilized to dry raw materials in the furnace, evaporated water vapor is guided out of the furnace in time, the lower calorific value of the materials is increased, and the problem that due to the fact that the moisture of the raw materials is too large, pyrolysis, gasification and combustion cannot be rapidly and directly conducted is solved. And the adaptability of direct pyrolysis gasification combustion energy utilization of the wet-based organic solid waste material is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste pyrolysis and incineration equipment, and in particular to a pyrolysis and gasification combustion furnace and a combustion treatment method for organic solid waste. Background Art

[0002] Among organic solid wastes, the initial moisture content of Chinese medicine residues, distiller's grains, and discarded edible mushroom sticks is 55-85%, which is a wet-based organic solid waste. It is produced in large quantities, has a high moisture content, is easy to rot, has a peculiar smell, and some drugs or bacterial residues are difficult to degrade. The traditional treatment processes mainly include landfill, anaerobic fermentation, aerobic composting, feed additives, etc., which have the problems of small disposal scale, long treatment cycle, and easy to cause environmental pollution. On the other hand, wastes such as Chinese medicine residues and waste mushroom sticks are also biomass with high organic matter and high volatile content. The dry basis calorific value can reach more than 3500kcal / kg, and it has the characteristics of concentrated emissions, and has the potential for centralized energy disposal and utilization.

[0003] The existing biomass organic solid waste pyrolysis gasification combustion system is only suitable for the treatment of materials with low moisture content. For high-moisture organic solid waste, independent drying equipment is required to reduce the material to the ideal level through dehydration and drying before pyrolysis gasification or combustion. The water removed by mechanical filter pressing and other methods is limited. It is necessary to introduce external heat source or reuse the heat source to perform thermal drying in the drying system before feeding the combustion furnace to reduce the moisture content in the raw material to the ideal level, resulting in high operating energy consumption for dehydration, drying and thermal conversion of the system. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a pyrolysis gasification combustion furnace and a combustion treatment method for organic solid waste, wherein a dryer is arranged in the combustion furnace and the heat of pyrolysis gasification is used to dry the wet-based organic solid waste.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] The first aspect of the present invention provides a pyrolysis gasification combustion furnace, wherein the furnace body includes a secondary combustion zone, a drying zone, and a pyrolysis gasification zone which are interconnected from top to bottom;

[0007] A dryer is provided at the center of the drying area. The dryer is a cylindrical structure with an open top. A feed hole is provided on the side wall of the cylindrical structure. The feed hole is connected to the feed port of the furnace body. The bottom of the cylindrical structure is an inverted cone with a larger top and a smaller bottom. The cone angle of the inverted cone is connected to a drying air distribution device. The drying air distribution device includes a spiral coil. The spiral coil is coiled in the furnace body.

[0008] A water vapor recovery pipe is provided above the upper opening of the dryer, and the water vapor recovery pipe is connected to the outside of the furnace body;

[0009] The pyrolysis and gasification zone is provided with a pyrolysis and gasification air distribution device;

[0010] A smoke outlet is provided on the side of the secondary combustion zone.

[0011] The second aspect of the present invention provides a pyrolysis gasification combustion system, comprising the above-mentioned pyrolysis gasification combustion furnace, a feeding device, a slag discharge device, an air distribution device, and a smoke exhaust device;

[0012] The feeding device comprises a hopper, and the hopper is connected to the feeding port of the furnace body through a screw feeder.

[0013] The slag discharge device is connected to the slag discharge pipe;

[0014] The air distribution device is respectively connected to the burning zone air distribution device, the pyrolysis gasification air distribution device, the drying air distribution device and the secondary air distribution port;

[0015] The smoke exhaust device is connected to the smoke outlet.

[0016] The third aspect of the present invention provides a combustion treatment method for organic solid waste based on the above-mentioned pyrolysis gasification combustion system. The combustion treatment method comprises the following steps:

[0017] S1. After filter pressing, dehydration and homogenization, the wet organic solid waste particles enter the dryer inside the pyrolysis gasification furnace through the hopper and the spiral feeding device. The materials are forced to evaporate quickly to remove moisture under the action of the dry air blown by the dry air distribution device. The removed moisture is absorbed by the water vapor recovery pipe and discharged out of the furnace. When the gravity of the material is less than the buoyancy of the dry air, it is ejected from the top edge of the dryer, completing the drying process of the material;

[0018] S2. The materials that have completed the drying process are evenly dispersed and fall onto the grate in the pyrolysis and gasification zone. Under the action of the pyrolysis and gasification air blown by the pyrolysis and gasification air distribution device, the materials are pyrolyzed and gasified to generate hot flue gas, which includes combustible gas and solid ash;

[0019] S3: The air distribution pressure of the air distribution device in the burning zone is lower than that of the air distribution device in the pyrolysis gasification zone, so that the solid ash generated in S2 enters and stays in the burning zone. Under the action of the burning air distribution blown by the air distribution device in the burning zone, the ash forms a layered burning state, and the inorganic ash that has been burned is discharged out of the furnace through the slag discharge device.

[0020] The hot flue gas and the mixed gas with sensible heat generated in S4 and S2 move upward, form a swirl state under the action of the tangential wind of the secondary air distribution port, enter the secondary combustion zone for full combustion, enter the smoke exhaust device through the flue gas outlet, and be discharged.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The present invention uses reasonable structural design to directly and efficiently utilize the heat generated by the thermochemical conversion process to dry the raw materials in the furnace, and promptly guide the evaporated water vapor out of the furnace, thereby increasing the low calorific value of the material and solving the problem of being unable to quickly and immediately directly pyrolyze, gasify and burn the raw materials due to excessive moisture content. At the beginning of startup, an external heat source is required to preheat the furnace body. After normal operation, no additional heat source is required, and the moisture content of the appropriate materials entering the furnace can be increased to more than 60%, greatly improving the adaptability of direct pyrolysis, gasification and combustion energy utilization of wet-based organic solid waste materials.

[0023] 2. The present invention establishes physical isolation of material drying, pyrolysis gasification and secondary combustion space and organic coupling of chemical reaction processes, thereby improving the heat and mass transfer efficiency between materials, ensuring that the thermochemical reaction of materials is uniform, sufficient, rapid and efficient, promoting the full decomposition of components such as macromolecular tar substances, ash and fly ash carbon residues, and realizing the maximum energy conversion of organic matter.

[0024] 3. The combustion treatment method in the present invention is a pyrolysis gasification coupled combustion process, which is used to treat wet-based organic solid waste, so that pyrolysis gasification and combustion are both operated in a low-oxygen or oxygen-controlled environment, with a low excess air coefficient, which greatly reduces the exhaust volume, and can inhibit the generation rate of pollutants such as nitrogen oxides and particulate matter in the flue gas, facilitate the recovery and utilization of high-temperature flue gas heat, and reduce the investment in flue gas treatment equipment. The thermal drying of wet-based materials and pyrolysis gasification combustion are integrated into one, with a more reasonable and compact structure, simple system process, reduced floor space, saved drying equipment investment, high energy utilization, low operating cost, and better economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for illustration only.

[0027] Figure 1 Schematic diagram of the structure of the pyrolysis gasification combustion system in the embodiment.

[0028] Among them, 1. hopper; 2. screw feeder; 3. dryer; 4. pyrolysis gasification zone; 5. burning zone; 6. bracket; 7. slag discharge device; 8. burning zone air distribution device; 9. pyrolysis gasification air distribution device; 10. hood air distribution device; 11. drying air distribution device; 12. dryer support plate; 13. water vapor recovery pipe; 14. throat; 15. secondary air distribution port; 16. spoiler; 17. flue gas outlet; 18. secondary combustion zone. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0030] Embodiment 1:

[0031] An organic solid waste pyrolysis gasification combustion furnace, such as Figure 1 As shown, the furnace body includes, from top to bottom, a secondary combustion zone 18, a drying zone, and a pyrolysis gasification zone 4 which are interconnected;

[0032] A dryer 3 is provided at the center of the drying area. The dryer 3 is a cylindrical structure with an opening at the top. A feed hole is provided on the side wall of the cylindrical structure, and the feed hole is connected to the feed port of the furnace body. The bottom of the cylindrical structure is an inverted cone with a larger top and a smaller bottom. The cone angle of the inverted cone is connected to a drying air distribution device 11. The drying air distribution device 11 includes a spiral coil, and the spiral coil is coiled in the furnace body.

[0033] A water vapor recovery pipe 13 is provided above the upper opening of the dryer 3, and the water vapor recovery pipe 13 is connected to the outside of the furnace body;

[0034] A pyrolysis gasification air distribution device 9 is provided at the bottom of the pyrolysis gasification zone 4 , and a hood air distribution device 10 including a hood assembly is provided inside the pyrolysis gasification air distribution device 9 .

[0035] A smoke outlet 17 is provided on the side of the secondary combustion zone 18 .

[0036] With such an arrangement, the heat generated by the thermochemical conversion process in the furnace can be collected through the spiral coil, the raw materials in the furnace can be dried directly and efficiently, and the evaporated water vapor can be promptly discharged out of the furnace, thereby increasing the low calorific value of the material, and solving the problem of the inability to quickly and immediately carry out direct pyrolysis, gasification and combustion treatment due to excessive moisture in the raw materials; the moisture content of the suitable material entering the furnace can be increased to more than 60%, greatly improving the adaptability of direct pyrolysis, gasification and combustion energy utilization of wet-based organic solid waste materials.

[0037] The dryer 3 is fixed in the furnace body through a dryer support plate 12. One end of the dryer support plate 12 is fixed to the cylindrical structure of the dryer 3, and the other end is fixed to the side wall of the furnace body.

[0038] Preferably, the dryer support plates 12 are intermittently distributed radially around the dryer 3 to prevent the hot flue gas from being blocked from rising.

[0039] There are multiple water vapor recovery pipes 13, which are straight pipes that penetrate the side wall of the furnace body, with one end opening arranged above the upper end opening of the dryer 3 and the other end communicating with the outside of the furnace body.

[0040] Preferably, the bottom pipe openings of the plurality of water vapor recovery pipes 13 are spaced apart at set gaps to evenly cover the top of the uncovered open top of the dryer 3, so as to centrally collect the high-water-content gas generated at the opening on the barrel of the dryer 3, thereby preventing the tubular opening from being too large so that too much combustible gas escapes through the water vapor recovery pipe 13.

[0041] The spiral coil is wound on the inner wall of the furnace body below the dryer 3, and can collect the heat of the pyrolysis and gasification zone 4 so that the blown dry air reaches the set temperature.

[0042] The secondary combustion zone 18 is connected to the drying zone through the throat 14. The channel size at the throat 14 is smaller than that of the secondary combustion zone 18 and the drying zone. The connection position has a smooth transition to make the airflow state entering the secondary combustion zone 18 as uniform as possible.

[0043] The throat 14 is a cylindrical section, and a secondary air distribution port 15 is provided on the side of the cylindrical section. The secondary air distribution port 15 enters the furnace along a tangential direction. The tangential air intake can transform the airflow entering the secondary combustion zone 18 into a swirl state, thereby promoting uniform mixing of the tangential air intake.

[0044] A plurality of spoilers 16 are provided above the throat 14 of the secondary combustion zone 18. The spoilers 16 are used to further form turbulence inside the secondary combustion zone 18 to promote complete combustion.

[0045] Preferably, the spoiler 16 is obliquely connected to the side wall of the furnace body, and the gap between the spoiler 16 and the side wall of the furnace body forms a tortuous flue gas channel; the airflow is prevented from passing directly through the secondary combustion zone 18 and being discharged directly from the flue gas outlet 17, thereby ensuring the full progress of the combustion reaction; at the same time, it can also intercept fly ash of larger particle size that has not been completely reacted to prevent it from being directly carried out of the furnace by the flue gas.

[0046] Preferably, the connection position between the spoiler 16 and the side wall of the furnace body is lower than the gap between the spoiler 16 and the side wall of the furnace body, so that the airflow direction is consistent with the inclination direction of the spoiler 16, ensuring that the smoke can flow through and preventing backflow.

[0047] A soot blowing port is provided at the connection position between the spoiler 16 and the side wall of the furnace body. The soot blowing port is designed to regularly remove the accumulated ash attached to the inner wall of the furnace body and the spoiler 16, and cooperate with the secondary air distribution of the throat 14 to ensure smooth airflow and combustion efficiency in the secondary combustion zone 18.

[0048] The soot blowing port is located below the connection position between the spoiler 16 and the side wall of the furnace body, but slightly higher than the lowest point of the tortuous flue gas channel formed between the spoiler 16 and the side wall of the furnace body; such a position selection can ensure that the soot blowing airflow can effectively cover the ash accumulation area while avoiding excessive interference with the normal flue gas flow.

[0049] The soot blowing port is designed to be circular or elliptical to adapt to the shape and injection angle of the soot blowing nozzle. The diameter or length and width of the soot blowing port is determined according to the specifications of the soot blowing nozzle and the required soot blowing area to ensure sufficient soot blowing coverage and soot blowing effect.

[0050] A sootblowing nozzle is installed in the sootblowing port. The shape and angle of the nozzle should be optimized according to the furnace structure and ash accumulation conditions. The nozzle can be spiral, direct or combined to provide sufficient sootblowing pressure and coverage.

[0051] The sootblower port is made of high temperature resistant and corrosion resistant materials, such as stainless steel or high temperature alloy, to withstand the erosion of high temperature and corrosive gas in the furnace.

[0052] The soot blowing port is connected to a soot blowing system, which includes a compressed gas source, a soot blowing pipeline, a control system, etc., wherein the compressed gas source can be ambient air or oxygen-enriched air.

[0053] A burning zone 5 is arranged at the center of the pyrolysis gasification zone 4, the top surface of the burning zone 5 is higher than the hood air distribution device 10, the bottom surface of the central position of the burning zone 5 is lower than the hood air distribution device 10, and a burning zone air distribution device 8 is arranged below the burning zone 5; between the burning zone 5 and the pyrolysis gasification zone 4, by reasonably setting the air distribution pressure of the burning zone 5 and the pyrolysis gasification zone 4, solid ash such as fly ash is concentrated in the burning zone 5;

[0054] The center position of the burning zone 5 is connected to the slag discharge device 7, and the slag discharge device 7 is a pipeline passing through the burning zone air distribution device 8. The slag discharge device 7 is not connected to the burning zone air distribution device 8. The solid ash entering the slag discharge device 7 is discharged out of the furnace after the temperature is detected to be lower than the set value.

[0055] Example 2

[0056] A pyrolysis gasification combustion system, comprising the pyrolysis gasification combustion furnace in Example 1, a feeding device, an air distribution device, and a smoke exhaust device;

[0057] The feeding device comprises a hopper 1 , and the hopper 1 is connected to a feeding port of a furnace body through a screw feeder 2 .

[0058] The slag discharge device 7 is connected to the slag discharge pipe;

[0059] The air distribution device is respectively connected to the burning zone air distribution device 8, the pyrolysis gasification air distribution device 9, the drying air distribution device 11, the secondary air distribution port 15 and the soot blowing port;

[0060] The smoke exhaust device is connected to the smoke outlet 17 .

[0061] The smoke exhaust device includes a high-temperature waste heat utilization device and a purification treatment device.

[0062] The pyrolysis gasification combustion furnace is fixed at the installation position by a bracket 6 and maintains a vertical posture.

[0063] It also includes operation monitoring and control devices;

[0064] The operation monitoring and control device is connected to the slag discharge device 7 and can detect the temperature of the ash in the slag discharge device 7;

[0065] The operation monitoring and control device is connected to the drying air distribution device 11, the burning zone air distribution device 8, the pyrolysis gasification air distribution device 9, the secondary air distribution port 15 and the soot blowing port, and can detect the air volume, air pressure, temperature, and can adjust the air distribution volume online.

[0066] The combustion treatment method of organic solid waste based on the pyrolysis gasification combustion system of this embodiment includes the following steps:

[0067] S1. After filter pressing, dehydration and homogenization, the wet organic solid waste particles enter the dryer 3 inside the pyrolysis gasification furnace body from the hopper 1 through the screw feeder 2. Under the blowing action of the dry air blown by the dry air distribution device 11, the material is in a fountain-like bubbling fluidized state in the dryer 3, which promotes uniform contact and rapid heat transfer between the material and the dry air, and forces the material to evaporate quickly to remove moisture. The removed moisture is absorbed by the water vapor recovery pipe 13 and discharged out of the furnace body; the weight of the material gradually becomes lighter after dehydration, and when the gravity of the material is less than the buoyancy of the dry air, it is sprayed out from the top edge of the dryer 3, completing the material drying process;

[0068] S2. The materials that have completed the drying process are evenly dispersed and fall into the pyrolysis gasification zone 4. Under the action of the pyrolysis gasification air blown by the pyrolysis gasification air distribution device 9, pyrolysis gasification is carried out to generate hot flue gas, which includes combustible gas and solid ash;

[0069] S3, the air distribution pressure of the burning zone air distribution device 8 is lower than the air distribution pressure of the pyrolysis gasification air distribution device 9, so that the solid ash generated in S2 enters and stays in the burning zone 5. Under the action of the burning air distribution blown by the burning zone air distribution device 8, the ash forms a layer burning state, and the inorganic ash after burning is discharged out of the furnace through the slag discharge device 7;

[0070] The hot flue gas and the mixed gas with sensible heat generated in S4 and S2 move upward, form a swirl state under the action of the tangential wind of the secondary air distribution port 15, enter the secondary combustion zone 18 for full combustion, enter the smoke exhaust device through the smoke outlet 17, and are discharged.

[0071] Through the above steps, the physical isolation of material drying, pyrolysis gasification and secondary combustion space and the organic coupling of chemical reaction processes can be achieved, the heat and mass transfer efficiency between materials can be improved, and the thermochemical reaction of materials can be guaranteed to be uniform, sufficient, rapid and efficient; the full decomposition of components such as macromolecular tar substances, ash and fly ash residue can be promoted to achieve the maximum energy conversion of organic matter.

[0072] In S1, the moisture content of the wet-based organic solid waste particles is less than 60%, and the particle size is less than 10 mm; the material in the dryer 3 is in a fountain-like bubbling fluidized state, and the drying air blown out by the drying air distribution device 11 is hot air at 150-200°C; the moisture content of the material after the drying process is completed is less than 35%;

[0073] The drying air is hot air that absorbs the radiation conduction heat of the furnace pyrolysis and gasification zone 4 through the spiral coil, so that the material stays in the drying zone for 2 to 5 minutes.

[0074] In S1 , the water vapor recovery pipe 13 is maintained in a negative pressure state to reduce the amount of gas with excessive humidity entering the secondary combustion zone 18 .

[0075] In S1, the gas absorbed by the water vapor recovery pipe 13 is dehydrated and then introduced into the pyrolysis gasification furnace through other air distribution devices to participate in the reaction again as a reaction medium, so as to avoid the combustible gas that may exist in the extracted gas from being discharged into the atmosphere, causing energy loss or safety hazards or environmental pollution, etc.;

[0076] The gas absorbed by the water vapor recovery pipe 13 can be passed into the combustion zone air distribution device 8, the pyrolysis gasification air distribution device 9, the secondary air distribution port 15 and / or the soot blowing port after being dehydrated.

[0077] In S2, under the action of pyrolysis and gasification air distribution, a small part of the material undergoes oxidative combustion to maintain the temperature of pyrolysis and gasification zone 4 at 600-800°C; most of the remaining materials undergo a series of incomplete combustion thermochemical reactions such as pyrolysis and gasification quickly, evenly and efficiently, producing a mixed gas containing carbon monoxide, hydrogen, methane, carbon dioxide, unsaturated hydrocarbon small molecules and tar macromolecules, as well as solid ash containing some incompletely reacted residual carbon and inorganic components.

[0078] In S3, under the action of combustion air distribution, the ash is in a layered combustion state, achieving full decomposition and transformation of organic carbon residue and energy release.

[0079] In S3, when the operation monitoring and control device detects that the ash temperature in the layer combustion state drops to a limit value, it is considered that the combustion is complete, and the slag discharge device 7 is started to discharge the remaining inorganic ash out of the furnace layer by layer intermittently.

[0080] In S4, the hot flue gas and the mixed gas with sensible heat form a counter-movement with the material ejected and falling from the dryer 3, and further drying and preheating of the material particles are achieved through heat and mass transfer, providing good conditions for the thermochemical reaction between the material particles and the pyrolysis gasification air in the pyrolysis gasification zone 4.

[0081] In S4, the hot flue gas and the mixed gas with sensible heat are fully mixed with the secondary air distribution of the secondary air distribution port 15, and a turbulent state is formed through the throat 14 structure and the spoiler 16, thereby increasing the disturbance to the mixed gas and achieving full mixing with the secondary air distribution; at the same time, through the joint action of the throat 14 and the spoiler 16 of the turbulent structure, the air flow speed and path are controlled, and the air flow is adjusted to form a good turbulent state, avoiding the air flow from passing directly through the secondary combustion zone 18 and being discharged directly from the flue gas outlet 17, and can also prolong the residence and reaction time in the secondary combustion zone 18, thereby improving the combustion efficiency, ensuring the full progress of the combustion reaction, and promoting the release of heat.

[0082] In S4, the gas enters the smoke exhaust device and is discharged after being utilized and purified by high-temperature waste heat.

[0083] In S4, the cyclic opening and closing of each soot blowing port is set by the operation monitoring and control device to purge the ash accumulated between the spoiler 16 and the side wall of the pyrolysis gasification furnace body, so that the deposited and intercepted fly ash particles return to the secondary combustion zone 18 or fall to the pyrolysis gasification zone 4 to re-participate in the reaction. At the same time, the purge air can be discharged from multiple soot blowing ports as a supplement to the secondary air distribution. The air volume of multiple soot blowing ports can be adjusted to achieve gradient rich and thin combustion in the reaction environment conditions of the secondary combustion zone 18;

[0084] Specifically, gradient rich-lean combustion means that in the secondary combustion zone 18, by precisely controlling the opening and closing of each soot blowing port and the air volume, differences in oxygen concentration and airflow velocity are formed in local areas, thereby constructing an oxygen concentration gradient and a combustion intensity gradient in the combustion space; specifically, this control method makes the oxygen supply in some areas (rich areas) relatively sufficient and the combustion intensity high, which is conducive to the rapid decomposition and full combustion of difficult-to-burn components such as tar macromolecules and fly ash and carbon residues, thereby releasing more energy; while the other areas (lean areas) form a relatively mild combustion environment by reducing the oxygen supply or reducing the airflow velocity, which helps to inhibit the formation of nitrogen oxides and reduce the generation of fly ash; this gradient distribution not only promotes the deep combustion of organic matter and the efficient conversion of energy, but also optimizes the environmental impact of the combustion process, so that the entire combustion system has good environmental protection performance while ensuring high efficiency; through the precise control of the operation monitoring and control device, the degree of richness and thinness of each area can be dynamically adjusted to adapt to the changes in material properties and combustion requirements under different working conditions, so as to achieve refined control and optimization of the combustion process.

[0085] The air volume ratio of drying air, pyrolysis gasification air, combustion air, secondary air and purge air is: drying air volume: pyrolysis gasification air volume: combustion air volume: secondary air volume: purge air volume = (0.3~0.35): (0.3~0.35): (0.1~0.15): (0.3~0.4): (0.1~0.2).

[0086] The total air supply volume is 135% to 140% of the theoretical air volume for complete combustion of the materials entering the furnace; 30% to 35% of it is the air supply for material drying, which basically does not participate in the thermochemical reaction of the materials, that is, it enters the furnace through the drying air supply device 11 to provide heat for the drying process in the dryer 3, and carries the evaporated water vapor, which is directly guided out of the furnace through the water vapor recovery pipe 13. Therefore, the total air volume entering the furnace and actually participating in the reaction is 105% to 110% of the theoretical air volume for complete combustion of the materials entering the furnace.

[0087] The gas absorbed by the water vapor recovery pipe 13 can be passed into the combustion zone air distribution device 8, the pyrolysis gasification air distribution device 9, the secondary air distribution port 15 and / or the soot blowing port after being dehydrated, and become the combustion air, pyrolysis gasification air, secondary air and / or purge air to re-enter the furnace for reaction, thereby avoiding the combustible gas that may exist in the extracted gas from being discharged into the atmosphere, causing energy loss or safety hazards or environmental pollution.

[0088] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A pyrolysis gasification combustion furnace, characterized in that: The furnace body includes, from top to bottom, a secondary combustion zone, a drying zone, and a pyrolysis and gasification zone which are interconnected; A dryer is provided at the center of the drying area. The dryer is a cylindrical structure with an open top. A feed hole is provided on the side wall of the cylindrical structure. The feed hole is connected to the feed port of the furnace body. The bottom of the cylindrical structure is an inverted cone with a larger top and a smaller bottom. The cone angle of the inverted cone is connected to a drying air distribution device. The drying air distribution device includes a spiral coil. The spiral coil is coiled in the furnace body. A water vapor recovery pipe is provided above the upper opening of the dryer, and the water vapor recovery pipe is connected to the outside of the furnace body; The pyrolysis and gasification zone is provided with a pyrolysis and gasification air distribution device; A smoke outlet is provided on the side of the secondary combustion zone.

2. The pyrolysis gasification combustion furnace according to claim 1, characterized in that: The dryer is fixed in the furnace body through a dryer support plate, one end of the dryer support plate is fixed to the cylindrical structure of the dryer, and the other end is fixed to the side wall of the furnace body; Preferably, the dryer support plates are intermittently distributed radially around the dryer; Optionally, the number of the water vapor recovery pipes is multiple, and the water vapor recovery pipe is a straight pipe that passes through the side wall of the furnace body, one end of the opening is arranged above the upper end opening of the dryer, and the other end is connected to the outside of the furnace body; Optionally, the spiral coil is wound on the inner wall of the furnace body below the dryer.

3. The pyrolysis gasification combustion furnace according to claim 1, characterized in that: The secondary combustion zone is connected to the drying zone through a throat, the channel size at the throat position is smaller than that of the secondary combustion zone and the drying zone, and the connection position has a smooth transition; Optionally, the throat is a cylindrical section, and a secondary air distribution port is provided on the side of the cylindrical section, and the secondary air distribution port enters the furnace along a tangential direction; Optionally, a plurality of spoilers are provided above the throat of the secondary combustion zone; Preferably, the spoiler is obliquely connected to the side wall of the furnace body, and the gap between the spoiler and the side wall of the furnace body forms a smoke channel; Preferably, the connection position between the spoiler and the side wall of the furnace body is lower than the gap between the spoiler and the side wall of the furnace body; Preferably, a soot blowing port is provided at the connection position between the spoiler and the side wall of the furnace body.

4. The pyrolysis gasification combustion furnace according to claim 1, characterized in that: The pyrolysis gasification air distribution device comprises a hood air distribution device provided with a hood assembly; Optionally, a burning zone is provided at the center of the pyrolysis and gasification zone, the top surface of the burning zone is higher than the pyrolysis and gasification air distribution device, the bottom surface at the center of the burning zone is lower than the pyrolysis and gasification air distribution device, and a burning zone air distribution device is provided below the burning zone; The central position of the burning zone is connected to a slag discharge device, and the slag discharge device is a pipeline passing through the air distribution device of the burning zone.

5. A pyrolysis gasification combustion system comprising the pyrolysis gasification combustion furnace according to any one of claims 1 to 4, characterized in that: include: Feeding device, air distribution device and smoke exhaust device; The feeding device comprises a hopper, and the hopper and the feeding port of the furnace body are connected through a screw feeder; The slag discharge device is connected to the slag discharge pipe; The air distribution device is respectively connected to the combustion zone air distribution device, the pyrolysis gasification air distribution device, the drying air distribution device, the secondary air distribution port and the soot blowing port; The smoke exhaust device is connected to the smoke outlet, and the smoke exhaust device includes a high-temperature waste heat utilization device and a purification treatment device.

6. The pyrolysis gasification combustion system according to claim 1, characterized in that: It also includes operation monitoring and control devices; The operation monitoring and control device is connected to the slag discharge device and can detect the temperature of the ash inside the slag discharge device; the operation monitoring and control device is connected to the drying air distribution device, the burning zone air distribution device, the pyrolysis gasification air distribution device, the secondary air distribution port and the soot blowing port and can adjust the air distribution volume.

7. A method for treating organic solid waste by combustion using the pyrolysis gasification combustion furnace according to any one of claims 1 to 4 and / or the pyrolysis gasification combustion system according to any one of claims 5 to 6, characterized in that: The following steps are involved: S1. After filter pressing, dehydration and homogenization, the wet organic solid waste particles enter the dryer inside the pyrolysis gasification furnace body through the hopper and the spiral feeding device. The materials are forced to evaporate quickly to remove moisture under the action of the dry air blown by the dry air distribution device. The removed moisture is absorbed by the water vapor recovery pipe and discharged out of the furnace body. When the gravity of the material is less than the buoyancy of the dry air, it is ejected from the top edge of the dryer, completing the drying process of the material; S2. The materials that have completed the drying process are evenly dispersed and fall onto the grate in the pyrolysis and gasification zone. Under the action of the pyrolysis and gasification air blown by the pyrolysis and gasification air distribution device, the materials are pyrolyzed and gasified to generate hot flue gas, which includes combustible gas and solid ash; S3: The air distribution pressure of the air distribution device in the burning zone is lower than that of the air distribution device in the pyrolysis gasification zone, so that the solid ash generated in S2 enters and stays in the burning zone. Under the action of the burning air distribution blown by the air distribution device in the burning zone, the ash forms a layered burning state, and the inorganic ash that has been burned is discharged out of the furnace through the slag discharge device. The hot flue gas and the mixed gas with sensible heat generated in S4 and S2 move upward, form a swirl state under the action of the tangential wind of the secondary air distribution port, enter the secondary combustion zone for full combustion, enter the smoke exhaust device through the flue gas outlet, and be discharged.

8. The method for treating organic solid waste by combustion according to claim 7, characterized in that: In S1, the moisture content of wet-based organic solid waste particles is less than 60%, and the particle size is less than 10 mm; the material in the dryer is in a fountain-like bubbling fluidized state, and the drying wind is hot air at 150-200°C; the moisture content of the material after the drying process is less than 35%; Optionally, in S1, the water vapor recovery pipe is maintained in a negative pressure state; Optionally, in S1, the gas absorbed by the water vapor recovery pipe is dehydrated and then introduced into the pyrolysis gasification furnace through other air distribution devices.

9. The method for treating organic solid waste by combustion according to claim 7, characterized in that: In S2, the temperature of the pyrolysis and gasification zone is 600-800°C; Optionally, in S3, when the operation monitoring and control device detects that the ash temperature at the slag discharge port drops to a limited value, it is considered that the burning is complete, and the slag discharge device is started to discharge the residual inorganic ash out of the furnace layer by layer intermittently; Optionally, in S4, the hot flue gas and the mixed gas with sensible heat are mixed with the secondary air distribution of the secondary air distribution port, and a turbulent state is formed through the throat structure and the spoiler; Optionally, in S4, the cyclic opening and closing operation of each soot blowing port is set by operating the monitoring and control device to blow away the ash accumulated between the spoiler and the side wall of the pyrolysis gasification furnace body, so that the deposited and intercepted fly ash particles return to the secondary combustion zone or fall into the pyrolysis gasification zone to re-participate in the reaction. At the same time, the purge air serves as a supplement to the secondary air supply, so that the reaction environment conditions in the secondary combustion zone can achieve gradient rich and thin combustion.

10. The method for treating organic solid waste by combustion according to claim 7, characterized in that: The air volume ratio of drying air, pyrolysis gasification air, combustion air, secondary air and purge air is (0.3~0.35):(0.3~0.35):(0.1~0.15):(0.3~0.4):(0.1~0.2); The total air volume is 135% to 140% of the theoretical air volume for complete combustion of the materials entering the furnace, and the total air volume entering the furnace and actually participating in the reaction is 105% to 110% of the theoretical air volume for complete combustion of the materials entering the furnace.

Images