Incinerator with primary air duct structure

Abstract

This utility model relates to the field of incinerator technology, and in particular to an incinerator with a primary air duct structure. The incinerator body includes a grate and an ash hopper at the bottom. A primary air duct is installed inside the ash hopper, extending from its side to the center and then upwards to below the grate. The distance between the bottom of the grate and the outlet of the primary air duct is 0.5–1.5 m. Primary air is directly delivered to the central area of ​​the grate via the duct, concentrating and strengthening the air supply to this area through increased flow rate and pressure. This improves the "on-demand" primary air supply, making it suitable for incinerators where combustion is difficult in the middle. This results in a more uniform temperature field within the furnace, reduces localized high and low temperatures, and prevents coking, refractory material burn-out, the formation of a reducing gas atmosphere, or high-temperature damage to the grate bars. This improves the incinerator's operational stability, increases combustion efficiency, and extends the service life of the grate bars.

Description

Technical Field

[0001] This utility model relates to the field of incinerator technology, and in particular to an incinerator with a primary air duct structure. Background Technology

[0002] As the core equipment for solid waste incineration, the stability and combustion efficiency of the waste incinerator are crucial to the project's operation. The primary air in the incinerator plays a dominant role in the combustion of waste within the furnace; therefore, the air distribution system directly affects the incinerator's operational status.

[0003] In theory, the waste is spread evenly on the surface of the incinerator grate, and the gaps between the grate bars are also uniform. After the primary air enters from the primary air chamber at the bottom of the incinerator grate, it forms an equalizing chamber in the primary air chamber. The primary air is evenly distributed in the lower chamber of the grate and then enters the furnace through the gaps between the grate bars to participate in combustion.

[0004] The performance of a waste incinerator is affected by factors such as waste characteristics, equipment performance, and operational management. Due to limitations in the size and structure of the waste hoist, a thicker material layer often forms in the middle area and a thinner layer on both sides during waste feeding. Primary air enters from the primary air chamber at the bottom of the grate, forming a pressure equalization chamber within the chamber to provide the air required for combustion on the upper surface of the grate. The primary air is evenly distributed in the lower chamber of the grate before entering the furnace through the gaps between the grate bars to participate in combustion. In practical applications, due to the thicker and more resistant middle layer of waste material and the thinner and less resistant layers on both sides, coupled with the uneven gaps between the grate bars and the typically larger gaps between the side walls and the grate bars, the waste material layer on the grate surface tends to be thicker in the middle and thinner at the edges. This results in a large primary air supply to the sides of the grate and a small air supply to the middle area. Primary air easily enters the furnace from the left and right sides of the grate, leading to faster combustion of waste on the sides of the furnace. The smaller air supply and thicker waste layer in the middle area prevent the fuel from fully contacting the air and forming a good combustion condition. Consequently, the waste in the middle area burns slowly, the fire line is uneven, and fuel incomplete combustion losses increase. This not only reduces combustion efficiency but also causes uneven temperature distribution in the furnace.

[0005] Furthermore, due to the differences in combustion conditions between the sides and the center, coking often occurs on the side walls of the furnace, easily leading to localized high and low temperatures within the furnace and causing uneven temperature distribution. This can also damage the refractory material of the furnace walls, shortening the incinerator's service life. Utility Model Content

[0006] The technical problem to be solved by this utility model is: in order to solve the problems existing in the prior art in the background art, to provide an incinerator with a primary air duct structure that addresses the problems of unreasonable air supply, difficulty in combustion in the middle of the incinerator grate, and slow combustion in the prior art, and enables "on-demand air supply" of primary air supply through structural improvement.

[0007] The technical solution adopted by this utility model to solve its technical problem is as follows: an incinerator with a primary air duct structure, including an incinerator body, which is the main place of the entire incineration process, providing space for the incineration of waste, allowing the waste to burn completely, converting the organic matter in the waste into inorganic matter, and realizing the reduction and harmless treatment of waste. The incinerator body is equipped with an incinerator grate and an ash hopper located at the bottom of the incinerator. The incinerator grate is used to carry and transport waste. Through the movement of the grate, the waste is continuously tumbled and stirred on the grate, increasing the contact area between the waste and air, promoting the drying, ignition and combustion process of the waste, and improving the combustion efficiency. The ash hopper is located at the bottom of the incinerator and is used to collect the ash produced after combustion, facilitating the discharge of the ash. Subsequent processing: A primary air duct is installed inside the ash hopper. The primary air duct provides primary air to the incinerator. Primary air is one of the main air sources in the combustion process, which can meet the air requirements for the three stages of preheating, combustion, and burnout of waste on the grate. The primary air duct is installed on the side of the ash hopper, extends to the center of the ash hopper after entering, and then extends upward to the bottom of the incinerator grate. The reasonable layout and design of the primary air duct ensures that the primary air can be evenly delivered into the furnace, penetrate the waste layer to achieve complete combustion, improve combustion efficiency, reduce pollutant generation, and reduce carbon monoxide emissions. The distance between the bottom surface of the incinerator grate and the air outlet of the primary air duct is 0.5-1.5m, maintaining a 0.5-1.5m air pressure buffer zone to prevent high-speed flow from disturbing the combustion layer.

[0008] Furthermore, the primary air duct includes a primary air main pipe with an "L" shaped cross-section, serving as the main channel for transporting primary air. This allows the primary air to flow smoothly within the main pipe and be rationally distributed to the required locations. The outlet of the primary air main pipe is equipped with a primary air outlet baffle to prevent ash from falling into the primary air main pipe (3-1) and to regulate the outlet air volume and velocity of the primary air, further optimizing the supply of primary air to meet the primary air requirements of different combustion stages.

[0009] Furthermore, the primary air main pipe is divided into a primary air horizontal pipe and a primary air vertical pipe. The connection between the primary air horizontal pipe and the primary air vertical pipe is through an elbow. This structural design can better adapt to the internal space layout of the incinerator, allowing the primary air to enter the furnace along a predetermined path. At the same time, the elbow changes the flow direction of the primary air. A bypass pipe is provided at the elbow, which increases the flexibility and adjustability of the primary air pipe structure.

[0010] Furthermore, a valve is installed at the outlet of the bypass pipe to control the opening size of the bypass pipe, thereby adjusting the air volume ratio between the primary air main pipe and the bypass pipe. This allows operators to adjust the air volume according to actual needs and ensures a reasonable distribution of primary air volume.

[0011] Furthermore, the valve can be either a manual mode valve or an electric mode valve.

[0012] Furthermore, the outlet of the bypass pipe is located inside the ash hopper and directly opposite the ash outlet of the ash hopper, forming an air curtain barrier to prevent ash from rising, while creating a negative pressure environment inside the ash hopper to reduce the risk of ash hopper blockage.

[0013] Furthermore, the number of ash hoppers below the incinerator is one or more.

[0014] Furthermore, the spacing between the corresponding primary air ducts in the two ash hoppers is 1 to 3 meters to balance the uniformity of air supply and the compactness of the structure.

[0015] The beneficial effects of this utility model are as follows: This utility model directly delivers primary air to the middle area of ​​the grate through a duct, and strengthens the air supply to the middle area by concentrating the flow rate and pressure of the primary air, thereby changing the primary air supply structure and realizing centralized air supply to the middle area of ​​the grate. It is suitable for incinerators where combustion is difficult in the middle.

[0016] Firstly, because the temperature of the intermediate grate bars is high, the primary air duct faces the middle of the incinerator grate and is close to the incinerator grate body. The primary air duct structure in the ash hopper can instantly cool down the intermediate grate bars and improve their lifespan.

[0017] Secondly, the air supply is strengthened in areas with high air supply resistance and strong air demand in the middle, while the air supply is reduced in areas with low air supply resistance and moderate air demand on both sides. This increases the air volume and penetration in the middle, making the air distribution more reasonable, allowing the thicker garbage in the middle to fully contact the air, resulting in better combustion conditions, improved fuel combustion speed and efficiency, and reduced slag heat loss on ignition.

[0018] Third, it makes the temperature field of the entire furnace more uniform, reduces local high and low temperatures, and avoids damage to refractory materials, high-temperature coking in the furnace, formation of virgin gas atmosphere, or high-temperature damage to grate bars caused by local high temperatures.

[0019] Fourth, improve the operational stability of the incinerator, increase combustion efficiency within the furnace, and extend the service life of the grate bars. Ultimately, this will lead to a dual improvement in operational efficiency and management level. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this utility model;

[0022] Figure 2 This is a side view of the primary air duct inside the ash hopper of this utility model;

[0023] Figure 3 This is a structural schematic diagram of Embodiment 2 of the present invention;

[0024] In the diagram: 1. Incinerator grate, 2. Ash hopper, 3. Primary air duct, 3-1. Primary air main pipe, 3-1-1. Primary air horizontal pipe, 3-1-2. Primary air vertical pipe, 3-2. Primary air outlet baffle, 3-3. Bypass pipe, 3-4. Valve. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0026] Example 1: Single Ash Hopper

[0027] According to Bernoulli's principle, the kinetic energy, potential energy, and pressure energy of air are conserved during flow. At the primary air duct outlet, the air leaving the duct still possesses a certain amount of kinetic and pressure energy. However, due to the resistance loss inside the primary air chamber, the air resistance loss increases with the distance of departure, leading to a decrease in both kinetic and pressure energy. Therefore, to achieve this design effect, the distance between the primary air duct outlet and the grate surface is related to the air velocity and pressure of the fluid inside the duct.

[0028] Therefore, depending on the grate structure, such as Figures 1-2 The incinerator shown includes an incinerator body providing a high-temperature combustion space. The incinerator body is equipped with an incinerator grate 1 and an ash hopper 2 (i.e., a primary air chamber) located at the bottom of the incinerator, forming an integrated working chamber for incineration and ash removal. There is one ash hopper 2 at the bottom of the incinerator. The upper part of the incinerator grate 1 carries solid waste and maintains a permeable combustion layer. The bottom gap cooperates with the primary air duct to achieve penetrating oxygen supply. The ash hopper 2 collects incineration residue and prevents ash from entering the air duct system.

[0029] A primary air duct 3 is installed inside the ash hopper 2, serving as the main air delivery channel. This duct transports the combustion-supporting space from the side wall of the ash hopper 2 to directly below the incinerator grate 1. The primary air duct 3 is installed on the side of the ash hopper 2, extending into the center of the ash hopper 2 and then upwards to below the incinerator grate. This positions the primary air duct 3 in the middle of the incinerator grate 1, close to it. The increased primary air velocity and residual pressure enhance the air supply to this area, achieving the functions of cooling the grate bars of the incinerator grate 1, extending the lifespan of the grate bars, and increasing the air volume within the furnace to ensure complete combustion of the waste. The distance between the bottom surface of the incinerator grate 1 and the outlet of the primary air duct 3 is 0.5–1.5 meters. m, strengthen the air supply and penetration in the middle of the incinerator grate 1, change the primary air supply form, and achieve concentrated air supply to the middle area of ​​the grate by strengthening the flow rate and pressure of the primary air. The air distribution is more reasonable, so that the thicker garbage in the middle can fully contact the air. The combustion conditions are better, the combustion speed and efficiency of the fuel are improved, the slag heat loss rate is reduced, the temperature field of the entire furnace is more uniform, and local high temperature and low temperature are reduced. This avoids damage to refractory materials, high temperature coking in the furnace, formation of primordial gas atmosphere, or high temperature damage to grate bars caused by local high temperature. The above design is suitable for incinerators where intermediate combustion is difficult.

[0030] like Figure 1 As shown, the primary air duct 3 includes a primary air main pipe 3-1, which has an "L" shaped cross-section. To prevent ash from falling from the grate surface into the primary air main pipe 3-1, a primary air outlet baffle 3-2 is installed at the air outlet of the primary air main pipe 3-1. The primary air outlet baffle 3-2 can prevent ash from falling into the primary air main pipe 3-1 and also further guide the airflow at the primary air outlet.

[0031] In addition, if some ash and slag still enter the primary air main pipe 3-1, the primary air main pipe 3-1 is divided into a primary air horizontal pipe 3-1-1 arranged along the side wall of the ash hopper 2 and a primary air vertical pipe 3-1-2 precisely aligned with the ventilation holes of the incinerator grate 2. The connection between the primary air horizontal pipe 3-1-1 and the primary air vertical pipe 3-1-2 is connected by a bend. A bypass pipe 3-3 is provided at the bend. The bypass port 3-3 can discharge the ash and slag that have mistakenly entered the primary air main pipe 3-1.

[0032] The coordinated design of the primary air main pipe 3-1 and the bypass pipe 3-3 optimizes combustion.

[0033] In addition, the outlet of the bypass pipe 3-3 is located inside the ash hopper 2 and is directly opposite the ash outlet of the ash hopper 2.

[0034] like Figure 1As shown, a valve 3-4 is provided at the outlet of the bypass pipe 3-3. The valve 3-4 is a manual mode valve or an electric mode valve. The valve 3-4 is a flap valve, a slide valve, etc. The valve 3-4 is used to control the opening size of the bypass pipe 3-3 to adjust the air volume ratio between the primary air main pipe 3-1 and the bypass pipe 3-3, so as to achieve the purpose of local air supply intensity.

[0035] Workflow:

[0036] Step 1: Insert the primary air main pipe 3-1 from the side of the ash hopper 2, and extend the primary air horizontal pipe 3-1-1 laterally into the center of the ash hopper 2. At the same time, the primary air vertical pipe 3-1-2 coincides with the central axis of the ash hopper 2. The distance between the air outlet of the primary air vertical pipe 3-1-2 and the bottom surface of the incinerator grate 1 is 0.5 to 1.5 m.

[0037] Step 2: Install the primary air outlet baffle 3-2 at the outlet of the primary air riser 3-1-2;

[0038] Step 3: Adjust valve 3-4 according to the needs, thereby changing the outlet cross-section size of bypass pipe 3-3, and thus adjusting the air volume ratio between primary air main pipe 3-1 and bypass pipe 3-3 to adjust the local air supply intensity.

[0039] Step 4: After the primary air fan draws air from above the waste pit, it is heated to the temperature required for combustion by the air preheater, and then sent through the primary air duct 3 of the ash hopper 2 to the area near the bottom of the incinerator grate 1.

[0040] Step 5: The air from Step 4 is further guided through the primary air outlet baffle 3-2, blowing the air towards the incinerator grate 1, so that the waste is fully burned.

[0041] Example 2: Double Ash Hopper

[0042] The difference from Example 1 is as follows: Figure 3 As shown, there are two ash hoppers 2 below the incinerator. When there are two ash hoppers 2 at the bottom of the incinerator grate 1, the primary air duct 3 enters from the sides of the two ash hoppers 2 respectively, extends to the center of the ash hopper 2, then extends to about 1 / 3 of the incinerator grate 1, and then extends upward to the height of the lower part of the incinerator grate 1. The optimal distance is determined to be 0.5 to 1.5 meters, and the spacing between the corresponding primary air ducts 3 in the two ash hoppers is 1 to 3 meters.

[0043] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An incinerator with a primary air duct structure, comprising an incinerator body, wherein a grate (1) and an ash hopper (2) are installed in the incinerator body, and a primary air duct (3) is installed in the ash hopper (2), characterized in that: The primary air duct (3) is installed on the side of the ash hopper (2), extends into the center of the ash hopper (2), and then extends upward to the bottom of the incinerator grate. The distance between the bottom surface of the incinerator grate (1) and the outlet of the primary air duct (3) is 0.5 to 1.5 m.

2. The incinerator with a primary air duct structure according to claim 1, characterized in that: The primary air duct (3) includes a primary air main pipe (3-1), the cross-sectional shape of which is "L" shaped, and a primary air outlet baffle (3-2) is installed at the air outlet of the primary air main pipe (3-1).

3. An incinerator with a primary air duct structure according to claim 2, characterized in that: The primary air main pipe (3-1) is divided into a primary air horizontal pipe (3-1-1) and a primary air vertical pipe (3-1-2). The connection between the primary air horizontal pipe (3-1-1) and the primary air vertical pipe (3-1-2) is through an elbow, and a bypass pipe (3-3) is provided at the elbow.

4. An incinerator with a primary air duct structure according to claim 3, characterized in that: A valve (3-4) is provided at the outlet of the bypass pipe (3-3). The valve (3-4) is used to control the opening size of the bypass pipe (3-3) to adjust the air volume ratio between the primary air main pipe (3-1) and the bypass pipe (3-3).

5. An incinerator with a primary air duct structure according to claim 4, characterized in that: The valves (3-4) mentioned are manual mode valves or electric mode valves.

6. An incinerator with a primary air duct structure according to claim 3, characterized in that: The outlet of the bypass pipe (3-3) is located inside the ash hopper (2) and is directly opposite the ash outlet of the ash hopper (2).

7. An incinerator with a primary air duct structure according to claim 1, characterized in that: The number of ash hoppers (2) below the incinerator is one or more.

8. An incinerator with a primary air duct structure according to claim 7, characterized in that: The distance between the corresponding primary air ducts (3) in the two ash hoppers is 1 to 3 m.

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