Fire grate distribution system and method for municipal waste incineration power generation

Abstract

The invention provides a fire grate material distribution system and method for municipal waste incineration power generation, the fire grate material distribution system comprises a fire grate, a waste feeding chute and a waste distribution pretreatment device arranged at the front end of the fire grate, the waste distribution pretreatment device comprises a first chain scraper conveyor, a second chain scraper conveyor, a spiral conveyor, a bidirectional chute and a waste rectifying device, the first chain scraper conveyor is obliquely arranged, the discharging end is provided with a bidirectional chute, the feeding end is adjacent to the feeding end of the second chain scraper conveyor, the discharging port is located on the upper portion of a fire grate inlet, and the spiral conveyors are arranged on the left side and the right side of the second chain scraper conveyor respectively. A discharging port of the spiral conveyor is located above the fire grate inlet and below the discharging port of the second chain plate conveyor, a hot air pipe is connected to a shell of the spiral conveyor through a plurality of branch pipes, and the garbage rectifying device is used for conducting flow guiding and tiling on garbage. According to the system and the method, the household garbage about to enter the fire grate can be pre-quickly and uniformly distributed, the garbage distribution on the fire grate is adjusted, and the combustion efficiency of the garbage incinerator is improved in an auxiliary manner.

Description

Technical Field

[0001] This invention belongs to the field of waste-to-energy, and particularly relates to a grate feeding system and feeding method for municipal waste incineration power generation. Background Technology

[0002] Traditionally, municipal solid waste was treated through landfills. However, due to rapid urbanization, landfilling is no longer sufficient to meet the demands of waste disposal, given the limited land available around towns and the rate of waste generation. This also aligns with environmental requirements. Therefore, waste-to-energy incineration technology has emerged. This technology alleviates the problem of disposing of large amounts of municipal solid waste to some extent and generates electricity, thus achieving resource utilization of waste.

[0003] The mainstream method for municipal solid waste incineration power generation is to use an incinerator to burn municipal solid waste for heat extraction and generate electricity. Combustion efficiency is a crucial technical aspect, directly affecting power generation efficiency and the control of combustion pollutants. Incomplete combustion not only affects power generation efficiency but also produces harmful pollutants such as dioxins. The incinerator grate system is key to ensuring stable waste transport and efficient combustion within the incinerator; therefore, its rational design is essential. Existing technologies, including hydraulic reciprocating grates, combined grates, and rolling grates, all aim to achieve more uniform waste distribution, facilitating preheating and combustion of municipal solid waste within the incinerator.

[0004] In the field of municipal solid waste incineration technology in China, traditional combined inclined and forward-pushing grates are mostly used. Their advantages are moderate cost and simple maintenance, but the material distribution effect is generally poor. Some use imported Japanese L-type or R-type grates, which are more expensive and require specific calorific value municipal solid waste (requiring multiple pretreatment steps) to achieve better results. Therefore, the design of grate systems in the field of municipal solid waste power generation is far from meeting the needs of use, and there is an urgent need for a more efficient grate system. Summary of the Invention

[0005] The purpose of this invention is to provide a grate feeding system for municipal solid waste incineration power generation. This system can pre-distribute municipal solid waste that is about to enter the grate quickly and evenly, and adjust the distribution of waste on the grate to help improve the combustion efficiency of the waste incinerator.

[0006] Another objective of this invention is to provide a feeding method suitable for the above-described grate feeding system.

[0007] To achieve the above objectives, the technical solution of the present invention is a grate feeding system for municipal solid waste incineration power generation, comprising a grate, a waste feeding chute, and a waste distribution pretreatment device disposed at the front end of the grate. The waste distribution pretreatment device includes a first chain conveyor, a second chain conveyor, a screw conveyor, a bidirectional chute, and a waste rectification device. The first chain conveyor is arranged obliquely, with its discharge end higher than its inlet end. A bidirectional chute is installed at the discharge end. The inlet end is adjacent to the inlet end of the second chain conveyor. The second chain conveyor is horizontally positioned, with its discharge port located above the grate inlet. The discharge port of the waste inlet chute is located above the connection point between the first and second chain conveyors. Screw conveyors are arranged on the left and right sides of the second chain conveyor. The inlet of the screw conveyor is connected to the outlet of the bidirectional chute. The outlet of the screw conveyor is provided with a discharge chute, which is located above the grate inlet and below the outlet of the second chain conveyor. The outlets of the two discharge chutes are arranged opposite each other and are located on the three equal bisectors of the grate width. The outer shell of the screw conveyor is connected to a hot air pipe through several branch pipes for supplying hot air into the screw conveyor. The hot air pipe is connected to the primary air duct of the waste incinerator. The waste straightening device is located above the outlet end of the second chain conveyor, at a distance of 0.4 to 0.6 meters from the second chain conveyor, and is used to guide and spread the waste.

[0008] The first chain conveyor is arranged at an angle of 15 to 30 degrees.

[0009] The lower part of the front face of the waste rectification device is provided with a protrusion of the same width as the second chain conveyor. The lower side of the protrusion is set at an angle to the second chain conveyor. The lower side of the protrusion is V-shaped, with the lowest point being the center line of the lower side. The upper side of the protrusion is a downward slope.

[0010] The bottom surface of the waste rectification device has a notch, and the open surface of the notch is located on the bottom and rear side of the waste rectification device. A motor-driven rotating shaft is installed in the notch, and several material-pushing wheels are set on the rotating shaft. Each material-pushing wheel has three blades.

[0011] The front end face of the waste rectification device is provided with a shuttle-shaped wheel via a rotating shaft, and the upper side of the protrusion matches the shape of the shuttle-shaped wheel after the shuttle-shaped wheel is installed.

[0012] Waste baffles are provided on the left and right sides of the first and second chain conveyors, and the height of the waste baffles of the second chain conveyor is flush with the bottom edge of the waste rectification device.

[0013] The discharge port of the second chain conveyor is provided with an oblique discharge chute.

[0014] It also includes an inclined chute, which is arranged next to the second chain conveyor. The high end is located on the discharge side of the second chain conveyor and is flush with the garbage baffle. The bottom end is connected to the garbage collection pool. The inclined chute is equipped with a vibrator.

[0015] A method for placing materials in a grate feeding system for municipal solid waste incineration power generation includes the following steps. 1) The waste feeding chute is set above the connection between the first chain conveyor and the second chain conveyor. The waste released from the waste feeding chute falls into the adjacent area of ​​the first chain conveyor and the second chain conveyor. Finally, a small part of the waste is carried upward by the first chain conveyor into the bidirectional chute, and most of the waste is conveyed to the grate by the second chain conveyor. 2) The waste conveyed by the second chain conveyor is evenly spread out by the waste straightening device and enters the grate at a uniform speed through the inclined chute. 3) The waste entering the bidirectional chute enters the screw conveyor, is pre-dried by primary air, and is finally conveyed and released to the middle position of the grate.

[0016] This invention features a novel structure. Compared with existing technologies, it incorporates a new waste distribution pretreatment device between the original grate and the waste feeding chute. This device can efficiently and evenly distribute the waste that is about to enter the grate, while also solving the problem of saddle-shaped waste distribution on the grate, which tends to be low in the middle and high on both sides, thereby improving waste combustion efficiency. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the system of the present invention.

[0018] Figure 2 This is a schematic diagram of the waste distribution pretreatment device of the present invention.

[0019] Figure 3 This is a front side view of the waste rectification device.

[0020] Figure 4 This is a rear side view of the waste rectification device. Detailed Implementation

[0021] Example 1 like Figure 1-2 As shown, a feeding grate system for municipal solid waste incineration power generation includes a grate 1, a waste feeding chute 2, and a waste distribution pretreatment device 3 installed at the front end of the grate. The waste distribution pretreatment device 3 includes a first chain conveyor 31, a second chain conveyor 32, a screw conveyor 33, a bidirectional chute 34, and a waste rectification device 35. The first chain conveyor 31 is arranged obliquely, with its discharge end higher than its inlet end, at an angle of 15-30 degrees. A bidirectional chute 34 is provided at the discharge end of the first chain conveyor 31. The inlet end of the first chain conveyor 31 is adjacent to the inlet end of the second chain conveyor 32. Preferably, the inlet end of the first chain conveyor 31 slightly overlaps with the upper side of the inlet end of the second chain conveyor 32. The bidirectional chute 34 is an open-top box with two oblique chutes inside. The chute outlets are located on the lower left and right sides of the box. The second chain conveyor 32 is horizontally arranged, with its discharge port located above the grate 1 inlet. An oblique discharge chute 321 is provided at the discharge port of the second chain conveyor 32. The discharge port of the waste inlet chute 2 is located above the connection between the first chain conveyor 31 and the second chain conveyor 32. This arrangement utilizes two chain conveyors to transport the waste inlet chute 2... Part of the falling garbage is transported forward to the grate, and part is transported in reverse to the screw conveyors on both sides. Since the first chain plate conveyor 31 is set at an angle, during the movement of the chain plate, some garbage falling on it will fall into the second chain plate conveyor 32 due to gravity and the movement of the chain plate. Overall, the conveying capacity of the second chain plate conveyor 32 is greater than that of the first chain plate conveyor 31. Screw conveyors 33 are arranged on the left and right sides of the second chain conveyor 32. The inlet of the screw conveyor 33 is connected to the outlet of the bidirectional chute 34. The outlet of the screw conveyor 33 is provided with a discharge chute 36, which is located above the inlet of the grate 1 and below the outlet of the second chain conveyor 32. The outlets of the two discharge chute 36 are arranged opposite each other and are located on the three equal bisectors of the grate width. The outer shell of the screw conveyor 33 is connected to a hot air pipe 4 through several branch pipes for supplying hot air into the screw conveyor. The hot air pipe is connected to the primary air pipeline of the waste incinerator, and the primary air is supplied to the screw conveyor 33. The purpose of the above operation is to dry the waste in the screw conveyor 33 and place the waste in the middle of the grate. In the existing technology, after the waste falls into the incinerator, firstly, due to the complex composition of the waste, it is a loose material with cohesive force and friction. Moreover, the grate is equipped with refractory walls on both sides, and the waste will rub against the refractory walls. During operation, the waste in the middle of the grate will move faster than the waste on both sides, and the waste on the grate will be saddle-shaped. This uneven distribution will directly reduce the combustion efficiency of the waste. Therefore, the screw conveyor 33 slowly and adjustably puts a part of the pre-dried waste into the middle of the grate, so that the waste accumulation shape on the grate is uniform and the combustion efficiency is improved. This part of the waste released by the screw conveyor is mostly distributed in the upper layer of the waste on the grate, so pre-drying is more effective. The waste straightening device 35 is a plate-shaped object located above the discharge end of the second chain conveyor 32, with a distance of 0.4 to 0.6 meters between it and the second chain conveyor 32. It uses the gap between itself and the second chain conveyor 32 to guide and spread the waste on the second chain conveyor 32, ensuring that the waste falling into the grate is evenly spread.

[0022] In operation, the waste feeding chute is positioned above the connection between the first and second chain conveyors. Waste released from the chute falls into the area adjacent to the first and second chain conveyors. Part of the waste is carried upwards by the first chain conveyor into the bidirectional chute, while the other part is conveyed to the grate by the second chain conveyor. The waste conveyed by the second chain conveyor is evenly spread out by the waste straightening device and enters the grate through the inclined chute. The waste entering the bidirectional chute enters the screw conveyor, is pre-dried by primary air, and is finally conveyed and released to the center of the grate. Sensors on existing equipment are used to monitor the waste condition on the grate, and pre-dried waste is continuously added to the center of the grate to maintain the uniformity of the waste and ensure combustion efficiency.

[0023] Example 2

[0024] like Figure 3 As shown, in order to improve the performance of the waste rectification device 35, a protrusion 351 with the same width as the second chain conveyor 32 is provided on the lower part of its front end face. The lower side of the protrusion 351 is set at an angle to the second chain conveyor 32. The lower side of the protrusion is V-shaped, with the lowest point being the center line of the lower side. The upper side of the protrusion is a downward slope.

[0025] The waste is diverted to both sides by a V-shaped design resembling a ship's bow (as the waste falls onto the second chain conveyor 32 in a conical pile), which helps to spread out the waste released from the waste inlet chute, making it easier for the waste straightening device 35 to flatten the waste on the second chain conveyor.

[0026] Example 3

[0027] Furthermore, such as Figure 3 , 4 As shown, a notch is provided on the bottom surface of the waste rectification device 35. The open surface forming the notch is located on the bottom and rear side of the waste rectification device. A motor-driven rotating shaft is installed inside the notch, and several material-pushing wheels 352 are provided on the rotating shaft. Each material-pushing wheel has three blades. The purpose of this optimization is to reduce the length of the forced rectification channel formed by the waste rectification device 35 and the second chain conveyor 32. The material-pushing wheels assist the waste in passing through, alleviating the problem of blockage caused by sudden space constraints when the waste passes through the waste rectification device 35, and ensuring the smooth operation of the equipment.

[0028] Example 4

[0029] like Figure 4 As shown, the first and second chain conveyors are equipped with garbage baffles on their left and right sides. The height of the garbage baffle of the second chain conveyor is flush with the bottom edge of the garbage rectification device. A shuttle wheel 353 is installed on the front face of the garbage rectification device via a rotating shaft. The upper side of the protrusion after the shuttle wheel 353 is installed matches the shape of the shuttle wheel. It also includes an inclined chute, which is arranged next to the second chain conveyor. The high end is located on the discharge side of the second chain conveyor and is flush with the garbage baffle. The bottom end is connected to the garbage collection pool. The inclined chute is equipped with a vibrator. When there are large pieces of garbage or the garbage volume is large and overflows, the large pieces of garbage can be sent into the collection pool through the inclined chute with the assistance of the shuttle wheel.

Claims

1. A grate feeding system for municipal solid waste incineration power generation, characterized in that, The system includes a grate, a waste feeding chute, and a waste distribution and pretreatment device located at the front end of the grate. The waste distribution and pretreatment device includes a first chain conveyor, a second chain conveyor, a screw conveyor, a bidirectional chute, and a waste rectification device. The first chain conveyor is arranged obliquely, with its discharge end higher than its inlet end. A bidirectional chute is installed at the discharge end. The inlet end is adjacent to the inlet end of the second chain conveyor. The second chain conveyor is horizontally positioned, with its discharge port located above the grate inlet. The discharge port of the waste inlet chute is located above the connection point between the first and second chain conveyors. Screw conveyors are arranged on both sides of the second chain conveyor. The inlet of the screw conveyor is connected to the outlet of the bidirectional chute. The outlet of the screw conveyor is provided with a discharge chute, which is located above the grate inlet and below the outlet of the second chain conveyor. The outlets of the two discharge chutes are arranged opposite each other and are located on the third line of the grate width. The outer shell of the screw conveyor is connected to a hot air pipe through several branch pipes for supplying hot air into the screw conveyor. The hot air pipe is connected to the primary air duct of the waste incinerator. The waste straightening device is located above the discharge end of the second chain conveyor, with a distance of 0.4 to 0.6 meters between it and the second chain conveyor, and is used to guide and spread the waste.

2. The grate feeding system for municipal solid waste incineration power generation according to claim 1, characterized in that, The first chain conveyor is arranged at an angle of 15 to 30 degrees.

3. The grate feeding system for municipal solid waste incineration power generation according to claim 1, characterized in that, The lower part of the front face of the waste rectification device is provided with a protrusion of the same width as the second chain conveyor. The lower side of the protrusion is set at an angle to the second chain conveyor. The lower side of the protrusion is V-shaped, with the lowest point being the center line of the lower side. The upper side of the protrusion is a downward slope.

4. The grate feeding system for municipal solid waste incineration power generation according to claim 1, characterized in that, The bottom surface of the waste rectification device has a notch, and the open surface of the notch is located on the bottom and rear side of the waste rectification device. A motor-driven rotating shaft is installed in the notch, and several material-pushing wheels are set on the rotating shaft. Each material-pushing wheel has three blades.

5. The grate feeding system for municipal solid waste incineration power generation according to claim 1, characterized in that, The front end face of the waste rectification device is provided with a shuttle-shaped wheel via a rotating shaft, and the upper side of the protrusion matches the shape of the shuttle-shaped wheel after the shuttle-shaped wheel is installed.

6. The grate feeding system for municipal solid waste incineration power generation according to claim 1, characterized in that, Waste baffles are provided on the left and right sides of the first and second chain conveyors, and the height of the waste baffles of the second chain conveyor is flush with the bottom edge of the waste rectification device.

7. The grate feeding system for municipal solid waste incineration power generation according to claim 1, characterized in that, The discharge port of the second chain conveyor is provided with an oblique discharge chute.

8. The grate feeding system for municipal solid waste incineration power generation according to claim 1, characterized in that, It also includes an inclined chute, which is arranged next to the second chain conveyor. The high end is located on the discharge side of the second chain conveyor and is flush with the garbage baffle. The bottom end is connected to the garbage collection pool. The inclined chute is equipped with a vibrator.

9. The method for placing materials in the grate feeding system for municipal solid waste incineration power generation according to claim 1, characterized in that, Includes the following steps, 1) The waste feeding chute is set above the connection between the first chain conveyor and the second chain conveyor. The waste released from the waste feeding chute falls into the adjacent area of ​​the first chain conveyor and the second chain conveyor. Finally, a small part of the waste is carried upward by the first chain conveyor into the bidirectional chute, and most of the waste is conveyed to the grate by the second chain conveyor. 2) The waste conveyed by the second chain conveyor is evenly spread out by the waste straightening device and enters the grate at a uniform speed through the inclined chute. 3) The waste entering the bidirectional chute enters the screw conveyor, is pre-dried by primary air, and is finally conveyed and released to the middle position of the grate.

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