Household garbage pyrolysis system with high-temperature ash circulation and operation method

Abstract

The invention provides a household garbage pyrolysis system with high-temperature ash circulation and an operation method.The household garbage pyrolysis system with the high-temperature ash circulation comprises a garbage pyrolysis furnace module, a high-temperature ash collecting module and a high-temperature ash transporting and lifting module, the high-temperature ash collecting module is arranged at the bottom of the garbage pyrolysis furnace module, and the high-temperature ash transporting and lifting module is arranged at the bottom of the garbage pyrolysis furnace module; the waste pyrolysis furnace has the advantages that high-temperature ash generated in the pyrolysis process is fed into the furnace again through the high-temperature ash recycling device, the temperature in the waste pyrolysis furnace is increased, the yield of pyrolysis gas is increased, and the risk that tar blocks a pyrolysis gas outlet pipeline is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of garbage pyrolysis, and in particular to a domestic garbage pyrolysis system with high-temperature ash circulation and an operation method. Background Art

[0002] With the rapid development of economy and the acceleration of urbanization, the amount of domestic waste generated has increased. Domestic waste disposal has become one of the important issues in urban management. Traditional waste disposal methods mainly include landfill, composting and incineration. Although these methods have alleviated the pressure of waste disposal to a certain extent, they also have many problems.

[0003] Landfill is the most common way to dispose of garbage, but this method has a serious problem of wasting land resources. With the increasing shortage of urban land resources, the site selection of landfills is becoming more and more difficult. In addition, leakage problems in landfills may also lead to groundwater and soil pollution. Composting is a method of converting organic waste into fertilizer, but its processing efficiency is low and it has high requirements for garbage classification. In actual operation, due to incomplete garbage classification, the quality of compost is unstable and it is difficult to promote and apply on a large scale. Incineration can effectively reduce the volume and weight of garbage, but its investment and operating costs are high, and harmful substances such as dioxins may be produced during the incineration process, posing a threat to the environment and human health.

[0004] In recent years, pyrolysis technology has attracted widespread attention as an emerging waste treatment technology. Pyrolysis is a process in which organic matter in waste is decomposed into smaller molecules of gas, liquid and solid by high temperature under anaerobic or anoxic conditions. Pyrolysis technology can effectively reduce the volume of waste, while recovering heat energy and valuable chemicals to realize the resource utilization of waste.

[0005] However, the kitchen waste, paper and other water-absorbing materials contained in domestic garbage may not be able to effectively remove the bound water or adsorbed water in the garbage during a simple pretreatment process. The pyrolysis gas generated after entering the garbage pyrolysis furnace has a low temperature, and the content of moisture and polar compounds in the pyrolysis gas increases, resulting in reduced fluidity of the tar and a greatly increased probability of tar blockage at the pyrolysis gas outlet. Accordingly, the increase in temperature in the pyrolysis furnace can promote the cracking of organic matter, increase the output of pyrolysis gas, and reduce the generation of harmful substances such as dioxins. In addition, the high-temperature ash generated during the pyrolysis process has not been effectively utilized, resulting in a certain amount of heat loss. Summary of the invention

[0006] In order to overcome the above problems existing in the prior art, the present invention provides a domestic waste pyrolysis system with high-temperature ash circulation and an operation method.

[0007] The present invention discloses a domestic waste pyrolysis system with high-temperature ash circulation, comprising a waste pyrolysis furnace module, a high-temperature ash collection module and a high-temperature ash transportation and lifting module, wherein the high-temperature ash collection module is arranged at the bottom of the waste pyrolysis furnace module, and the high-temperature ash transportation and lifting module is arranged on the side of the waste pyrolysis furnace module; the waste pyrolysis furnace module comprises a furnace wall, a furnace top, a waste feed port, a high-temperature ash feed port, a waste quantity control valve, an ash quantity control valve, a buffer bin, a waste / high-temperature ash integrated inlet, an ash hopper and a slag outlet.

[0008] On this basis, the garbage / high-temperature ash integrated entrance is opened in the middle area of ​​the furnace top, the garbage inlet and the high-temperature ash inlet are respectively opened at both ends of the garbage / high-temperature ash integrated entrance, the buffer bin is set on the furnace top, the buffer bin outlet is connected to the high-temperature ash inlet, an ash quantity control valve is set between the buffer bin outlet and the high-temperature ash inlet, a garbage quantity control valve is set above the garbage inlet, the ash hopper is arranged at the lower part of the pyrolysis furnace, and the slag outlet is opened in the middle area of ​​the bottom of the ash hopper.

[0009] On this basis, the high-temperature ash collection module includes an ash storage bin and a slag discharge device. The ash storage bin inlet is connected to the slag outlet of the pyrolysis furnace, and the ash storage bin outlet is connected to the slag outlet on one side and to the high-temperature ash transportation and lifting module on the other side.

[0010] On this basis, the high-temperature ash transport and lifting module includes an elevator, the bottom of which is connected to the outlet of the ash storage bin, and the top is connected to the buffer bin.

[0011] On this basis, the ash storage bin and the buffer bin are both provided with heat preservation devices.

[0012] On this basis, the capacity of the buffer bin is calculated according to the rated ash discharge capacity, which shall not be less than 20 minutes.

[0013] A method for operating a domestic waste pyrolysis system with high-temperature ash circulation, wherein the amount of waste entering the furnace is adjusted by a waste quantity control valve, and the amount of high-temperature ash is adjusted by a high-temperature ash quantity control valve. The waste and high-temperature ash enter the waste pyrolysis furnace through a waste inlet and a high-temperature ash inlet, respectively, and then enter the waste pyrolysis furnace through a waste / high-temperature ash integrated inlet. The waste and high-temperature ash are mixed and pyrolyzed in the pyrolysis furnace, and the generated ash falls into the bottom of the ash hopper and enters the ash storage bin from the slag outlet for storage. A portion of the ash is transported to a buffer bin by a hoist, and another portion of the ash in the ash storage bin is discharged from the slag discharge device to the waste pyrolysis system; the hoist transports the high-temperature ash to the buffer bin and waits for the ash quantity control valve to adjust the ash quantity before entering the pyrolysis furnace.

[0014] On this basis, the single feeding time of garbage is controlled within 20s~120s, and the single feeding time of high-temperature ash is controlled within 30s~100s.

[0015] On this basis, in a single garbage and high-temperature ash feeding process, the ratio of the garbage feed mass flow rate to the high-temperature ash feed mass flow rate is 1:0.3 to 1:5.

[0016] On this basis, the garbage and high-temperature ash feeding method takes "garbage-high-temperature ash" as a cycle. In a single garbage and high-temperature ash feeding process, the garbage and high-temperature ash experience no less than 3 feeding cycles.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention sends the high temperature ash into the pyrolysis furnace through the high temperature ash collection module and the high temperature ash transportation and lifting module. Because the temperature is high when it is discharged from the pyrolysis furnace (the slag discharge temperature is usually higher than 500°C), when the high temperature ash is recycled back to the system, it is equivalent to a low-cost "fuel additive" to increase the calorific value of the material. When the high temperature circulating ash and the material enter the furnace, the material and the high temperature ash are in direct contact. This process is equivalent to the material being heated by an external heat source in the drying stage, thereby accelerating the drying process, and the pyrolysis gas coming out of the pyrolysis section is also heated by the high temperature circulating ash in the drying section, so that the pyrolysis gas discharge temperature of the pyrolysis furnace is significantly increased. At the same time, since the porosity of the material in the drying section is significantly increased due to the evaporation of water, and the height of the drying section is shortened, the uniformity of the pyrolysis gas passing through the material is significantly improved, the gas flow resistance will also be significantly reduced, and the risk of gas blockage in the drying section is also significantly reduced. In addition, the high temperature circulating ash may contain unburned carbon residues and other combustible components, and recycling it back to the pyrolysis furnace will help further burn out the combustible components in the high temperature circulating ash. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the garbage pyrolysis system of the present invention;

[0019] In the figure: A, pyrolysis furnace module; B, high-temperature ash collection module; C, high-temperature ash transportation and lifting module; 0, material; 1, garbage inlet; 2, high-temperature ash inlet; 3, garbage / high-temperature ash combined inlet; 4, ash hopper; 5, slag outlet; 6, furnace wall; 7, garbage quantity control valve; 8, ash storage bin; 9, elevator; 10, buffer bin; 11, ash quantity control valve; 12, furnace top; 13, slag discharge device. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0021] In a fixed bed pyrolysis furnace, material 0 goes through four stages of drying, pyrolysis, gasification and combustion in sequence, and the temperature of material 0 increases in sequence. Especially in the drying stage, the temperature of material 0 is usually low, generally not exceeding 200°C. Material 0 at this stage usually has a high moisture content, is prone to agglomeration and causes gas path blockage, thereby greatly increasing the unevenness of flue gas flow.

[0022] The present invention discloses a domestic waste pyrolysis system with high-temperature ash circulation, comprising a waste pyrolysis furnace module A, a high-temperature ash collection module B and a high-temperature ash transportation and lifting module C, wherein the high-temperature ash collection module B is arranged at the bottom of the waste pyrolysis furnace module A, and the high-temperature ash transportation and lifting module C is arranged on the side of the waste pyrolysis furnace module A. The waste pyrolysis furnace module A comprises a furnace wall 6, a furnace top 12, a waste feed port 1, a high-temperature ash feed port 2, a waste quantity control valve 7, an ash quantity control valve 11, a buffer bin 10, a waste / high-temperature ash integrated inlet 3, an ash hopper 4 and a slag outlet 5.

[0023] A garbage / high-temperature ash integrated entrance 3 is opened in the middle area of ​​the furnace top 12, a garbage feed port 1 and a high-temperature ash feed port 2 are respectively opened at both ends of the garbage / high-temperature ash integrated entrance 3, a buffer bin 10 is arranged on the furnace top 12, an outlet of the buffer bin 10 is connected to the high-temperature ash feed port 2, an ash quantity control valve 11 is arranged between the outlet of the buffer bin 10 and the high-temperature ash feed port 2, a garbage quantity control valve 7 is arranged above the garbage feed port 1, an ash hopper 4 is arranged at the lower part of the pyrolysis furnace, and a slag outlet 5 is opened in the middle area at the bottom of the ash hopper 4.

[0024] The high-temperature ash collection module B includes an ash storage bin 8 and a slag discharge device 13. The inlet of the ash storage bin 8 is connected to the slag outlet 5 of the pyrolysis furnace. One outlet of the ash storage bin 8 is connected to the slag outlet 5 and the other outlet is connected to the high-temperature ash transportation and lifting module C.

[0025] The high-temperature ash transport and lifting module C includes an elevator 9 , the bottom of which is connected to the outlet of the ash storage bin 8 , and the top of which is connected to the buffer bin 10 .

[0026] The ash storage bin 8 and the buffer bin 10 are both provided with heat preservation devices.

[0027] The capacity of the buffer bin 10 is calculated based on the rated ash discharge capacity and shall not be less than 20 minutes.

[0028] A method for operating a domestic waste pyrolysis system with high-temperature ash circulation, wherein the amount of waste entering the furnace is adjusted by a waste quantity control valve 7, and the amount of high-temperature ash is adjusted by a high-temperature ash quantity control valve 11. The waste and high-temperature ash enter the waste pyrolysis furnace through a waste inlet 1 and a high-temperature ash inlet 2, respectively, and then enter the waste pyrolysis furnace through a waste / high-temperature ash integrated inlet 3. The waste and high-temperature ash are mixed and pyrolyzed in the pyrolysis furnace, and the generated ash falls into the bottom of an ash hopper 4 and enters an ash storage bin 8 from a slag outlet 5 for storage. A portion of the ash is transported to a buffer bin 10 by an elevator 9, and another portion of the ash in the ash storage bin 8 is discharged from a slag discharge device 13 to discharge the waste pyrolysis system; the elevator 9 transports the high-temperature ash to the buffer bin 10 and waits for the ash quantity control valve 11 to adjust the ash quantity to enter the pyrolysis furnace.

[0029] The single feeding time of garbage is controlled within 20s~120s, and the single feeding time of high-temperature ash is controlled within 30s~100s.

[0030] In a single garbage and high-temperature ash feeding process, the ratio of the garbage feed mass flow rate to the high-temperature ash feed mass flow rate is 1:0.3 to 1:5.

[0031] The garbage and high-temperature ash feeding method takes "garbage-high-temperature ash" as a cycle. In a single garbage and high-temperature ash feeding process, the garbage and high-temperature ash experience no less than 3 feeding cycles.

[0032] refer to Figure 1 In this embodiment, the pyrolysis furnace is composed of a furnace wall 6 and a furnace roof 12, and its cross-section is rectangular, with a size of 5m×3m and a height of 10m. The garbage feed port 1 and the high-temperature ash inlet 2 are respectively opened on the left and right sides of the garbage / high-temperature ash integrated inlet 3. The garbage / high-temperature ash integrated inlet 3 is opened in the center of the furnace roof 12, and its shape is rectangular, with a size of 1m×1m. The ash hopper 4 is located at the bottom of the pyrolysis furnace. The slag outlet 5 is opened at the bottom of the ash hopper 4. The ash storage bin 8 is arranged on the right side of the pyrolysis furnace. The elevator 9 is arranged on the right side of the ash storage bin 8, with a height of 15m. The buffer bin 10 is arranged on the top of the pyrolysis furnace. Calculated according to the rated ash discharge volume, the buffer bin capacity can be maintained for 30 minutes.

[0033] In this embodiment, garbage 0 and high-temperature ash pass through garbage inlet 1 and high-temperature ash inlet 2 respectively, and then enter the garbage pyrolysis furnace through garbage / high-temperature ash integrated inlet 3, and the garbage and high-temperature ash are mixed and pyrolyzed in the pyrolysis furnace; the generated ash falls into the bottom of the ash hopper 4 and enters the ash storage bin 8 for storage from the slag outlet 5, and the elevator 9 transports the high-temperature ash from the ash storage bin 8 to the buffer bin 10, and the high-temperature ash control valve 11 controls the high-temperature ash to be fed once every 60 seconds, and the feeding time is 30 seconds; the garbage control valve 7 controls the garbage to be fed once every 30 seconds, and the feeding time is 30 seconds; the garbage Both garbage and high-temperature ash are fed evenly, with a single garbage feeding mass flow rate of 15t / d, and a high-temperature ash feeding mass flow rate of 20t / d. The garbage and high-temperature ash feeding method takes "garbage-high-temperature ash" as a cycle. The garbage and high-temperature ash complete the feeding process after 5 cycles of cyclic feeding. The garbage and high-temperature ash are mixed, dried and pyrolyzed in the pyrolysis furnace. After the pyrolysis of the garbage and high-temperature ash is completed, the ash generated falls into the bottom of the ash hopper 4 and enters the ash storage bin 8 from the slag outlet 5 for storage. Part of the ash in the ash storage bin 8 is discharged from the slag discharge device to the garbage pyrolysis system every 30 minutes.

[0034] Compared with the prior art, the present invention sends the high-temperature ash into the pyrolysis furnace through the high-temperature ash collection module B and the high-temperature ash transportation and lifting module C. Because the temperature is relatively high when it is discharged from the pyrolysis furnace (the slag discharge temperature is usually higher than 500°C), when the high-temperature ash is recycled back to the system, it is equivalent to being a low-cost "fuel additive" to increase the calorific value of material 0. When the high-temperature circulating ash and material 0 are entering the furnace, material 0 and the high-temperature ash are in direct contact. This process is equivalent to material 0 being heated by an external heat source in the drying stage, thereby accelerating the drying process, and the pyrolysis gas coming out of the pyrolysis section is also heated by the high-temperature circulating ash in the drying section, thereby significantly increasing the pyrolysis gas discharge temperature of the pyrolysis furnace. At the same time, since the porosity of material 0 in the drying section is significantly increased due to the evaporation of water, and the height of the drying section is shortened, the uniformity of the pyrolysis gas passing through material 0 is significantly improved, the gas path flow resistance will also be significantly reduced, and the risk of gas path blockage in the drying section is also significantly reduced. In addition, the high-temperature circulating ash may contain unburned carbon residues and other combustible components, and recycling it back to the pyrolysis furnace will help further burn out the combustible components in the high-temperature circulating ash.

[0035] In the description of the present invention, it is necessary to understand that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0036] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation", "screwing", "pad installation" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0037] The above description shows and describes the preferred embodiments of the present invention. As mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A domestic waste pyrolysis system with high-temperature ash circulation, characterized in that: The invention comprises a garbage pyrolysis furnace module (A), a high-temperature ash collection module (B) and a high-temperature ash transportation and lifting module (C), wherein the high-temperature ash collection module (B) is arranged at the bottom of the garbage pyrolysis furnace module (A), and the high-temperature ash transportation and lifting module (C) is arranged on the side of the garbage pyrolysis furnace module (A). The garbage pyrolysis furnace module (A) comprises a furnace wall (6), a furnace top (12), a garbage inlet (1), a high-temperature ash inlet (2), a garbage quantity control valve (7), an ash quantity control valve (11), a buffer bin (10), a garbage / high-temperature ash integrated inlet (3), an ash hopper (4) and a slag outlet (5).

2. The domestic waste pyrolysis system with high-temperature ash circulation according to claim 1 is characterized in that: The garbage / high-temperature ash integrated inlet (3) is opened in the middle area of ​​the furnace top (12); the garbage feed port (1) and the high-temperature ash feed port (2) are respectively opened at two ends of the garbage / high-temperature ash integrated inlet (3); the buffer bin (10) is arranged on the furnace top (12); the outlet of the buffer bin (10) is connected to the high-temperature ash feed port (2); an ash quantity control valve (11) is arranged between the outlet of the buffer bin (10) and the high-temperature ash feed port (2); a garbage quantity control valve (7) is arranged above the garbage feed port (1); the ash hopper (4) is arranged at the lower part of the pyrolysis furnace; and the slag outlet (5) is opened in the middle area at the bottom of the ash hopper (4).

3. The domestic waste pyrolysis system with high-temperature ash circulation according to claim 2 is characterized in that: The high-temperature ash collection module (B) comprises an ash storage bin (8) and a slag discharge device (13); the inlet of the ash storage bin (8) is connected to the slag outlet (5) of the pyrolysis furnace; one path of the outlet of the ash storage bin (8) is connected to the slag outlet (5) and the other path is connected to the high-temperature ash transport and lifting module (C).

4. The domestic waste pyrolysis system with high-temperature ash circulation according to claim 3 is characterized in that: The high-temperature ash transport and lifting module (C) comprises an elevator (9), the bottom of which is connected to the outlet of the ash storage bin (8), and the top of which is connected to the buffer bin (10).

5. The domestic waste pyrolysis system with high-temperature ash circulation according to claim 4 is characterized in that: The ash storage bin (8) and the buffer bin (10) are both provided with a heat preservation device.

6. The domestic waste pyrolysis system with high-temperature ash circulation according to claim 5, characterized in that: The capacity of the buffer bin (10) is calculated based on the rated ash discharge capacity and is not less than 20 minutes.

7. A method for operating a domestic waste pyrolysis system with high-temperature ash circulation according to claim 6, characterized in that: The amount of garbage entering the furnace is adjusted by the garbage amount control valve (7), and the amount of high-temperature ash is adjusted by the high-temperature ash amount control valve (11). The garbage and high-temperature ash enter the garbage pyrolysis furnace through the garbage inlet (1) and the high-temperature ash inlet (2) respectively, and then enter the garbage / high-temperature ash integrated inlet (3). The garbage and high-temperature ash are mixed and pyrolyzed in the pyrolysis furnace. The generated ash falls into the bottom of the ash hopper (4) and enters the ash storage bin (8) from the slag outlet (5) for storage. A part of the ash is transported to the buffer bin (10) by the elevator (9), and another part of the ash in the ash storage bin (8) is discharged from the garbage pyrolysis system through the slag discharge device (13); the elevator (9) transports the high-temperature ash to the buffer bin (10) and waits for the ash amount control valve (11) to adjust the ash amount to enter the pyrolysis furnace.

8. The method for operating a domestic waste pyrolysis system with high-temperature ash circulation according to claim 7, characterized in that: The single feeding time of garbage is controlled within 20s ~ 120s, and the single feeding time of high-temperature ash is controlled within 30s ~ 100s.

9. The method for operating a domestic waste pyrolysis system with high-temperature ash circulation according to claim 7, characterized in that: In a single garbage and high-temperature ash feeding process, the ratio of the garbage feeding mass flow rate to the high-temperature ash feeding mass flow rate is 1:0.3 to 1:

5.

10. The method for operating a domestic waste pyrolysis system with high-temperature ash circulation according to claim 7, characterized in that: The garbage and high-temperature ash feeding method takes "garbage-high-temperature ash" as a cycle. In a single garbage and high-temperature ash feeding process, the garbage and high-temperature ash experience no less than 3 feeding cycles.

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