Vertical flue of low nitrogen oxide heat recovery coke oven

Abstract

The utility model discloses a low nitrogen oxide heat recovery coke oven vertical flame path which comprises carbonization chamber main walls, carbonization chambers are positioned between two adjacent carbonization chamber main walls, chamber bottom horizontal flame paths are arranged at the bottoms of the carbonization chambers, vertical flame paths are arranged in the carbonization chamber main walls, and flame path air supply pipes are arranged in the vertical flame paths along the height direction. And the air supply amount of the flame path air supply pipe is gradually increased from top to bottom. The vertical flame path comprises a descending flame path and an ascending flame path which are arranged in the main wall of the carbonization chamber, the upper end of the descending flame path is communicated with the upper space of the carbonization chamber, the lower end of the descending flame path is communicated with the horizontal flame path at the bottom of the chamber, and the lower end of the ascending flame path is communicated with the horizontal flame path at the bottom of the chamber. The ratio of the chamber width B to the chamber height h of the carbonization chamber is 1: (2-4). A plurality of flame path air supply holes are formed in the sections of the air supply holes of the vertical flame path, and the number of the flame path air supply holes in the sections of the air supply holes is sequentially increased from top to bottom. The vertical flue of the heat recovery coke oven can effectively inhibit the generation of nitrogen oxides in the coking process.

Description

Technical Field

[0001] This utility model relates to a clean heat recovery coke oven, and more particularly to an improvement in the vertical flue structure of the clean heat recovery coke oven, which includes a descending flue and an ascending flue. Background Technology

[0002] Clean heat recovery coke ovens are a new type of coke oven that efficiently and completely combusts coke oven gas, chemical products, and some harmful substances generated during the coking process, recovering the heat from the high-temperature waste gas for power generation or other purposes. Clean heat recovery coke ovens not only significantly reduce environmental pollution hazards during the coking process, but also ensure the full and comprehensive utilization of waste heat resources.

[0003] Clean heat recovery coke ovens include a carbonization chamber and a combustion chamber. The combustion chamber, which provides heat for coking, mainly includes an upward fire channel and a downward fire channel installed in the partition wall of the carbonization chamber. Existing heat recovery coke ovens all use wide carbonization chambers for coking, resulting in large coke pieces. However, the excessively wide carbonization chambers severely affect the heat transfer efficiency in the central part of the chamber, leading to prolonged coking time, large footprint, and high investment costs. Narrowing the width of the coke carbonization chamber would inevitably increase its height and the length of the vertical flues (such as the rising and falling flues) in the main wall. While this could effectively reduce the coke oven's footprint and optimize heat transfer, the increased length of the rising and falling flues would lead to the following drawbacks: First, the increased length of the vertical flues would directly affect the thermal efficiency of the carbonization chamber walls, causing extreme unevenness in the content of combustible raw gas and combustion air in the rising and falling flues. This would result in differences in the combustion of raw gas in the rising and falling flues, leading to different amounts of heat generated. Consequently, the coke oven would be heated unevenly, affecting heating efficiency and coke quality. Secondly, the narrowing of the carbonization chamber and the lengthening of the vertical flue also lead to the generation of nitrogen oxides. Due to the lengthening of the vertical flue, localized intense combustion and high-temperature zones will form within it. Under high-temperature conditions, nitrogen in the combustion air will react with oxidation to generate thermal nitrogen oxides. Nitrogen oxides are a major source of air pollution, and the large-scale emission of nitrogen oxides will undermine the environmentally friendly characteristics of clean heat recovery coke ovens. Furthermore, under high-temperature combustion conditions, the generation rate of thermal nitrogen oxides accelerates rapidly. Studies have shown that for every 100-degree increase in temperature, the amount of nitrogen oxides generated increases by 6-7 times. The existence of localized high-temperature zones in the vertical flue becomes a major source of pollutants from the coke oven. Utility Model Content

[0004] In view of the above-mentioned shortcomings of the existing technology, the technical problem to be solved by this utility model is to provide a low nitrogen oxide heat recovery coke oven vertical flue, which not only occupies a small area and reduces investment costs, but also effectively suppresses the generation of nitrogen oxides during the coking process.

[0005] To solve the above-mentioned technical problems, the present invention provides a low-NOx heat recovery coke oven vertical flue, including a carbonization chamber main wall, the carbonization chamber being located between two adjacent carbonization chamber main walls, a bottom horizontal flue being provided at the bottom of the carbonization chamber, a vertical flue being provided inside the carbonization chamber main wall, and a flue air supply pipe being provided along the height direction inside the vertical flue, the air supply volume on the flue air supply pipe increasing sequentially from top to bottom.

[0006] Preferably, the vertical fire channel includes a descending fire channel and an ascending fire channel disposed in the main wall of the carbonization chamber. The upper end of the descending fire channel is connected to the upper space of the carbonization chamber, the lower end of the descending fire channel leads to the horizontal fire channel at the bottom of the chamber, and the lower end of the ascending fire channel is connected to the horizontal fire channel at the bottom of the chamber.

[0007] Preferably, the ratio of the width B to the height h of the carbonization chamber is 1:(2-4).

[0008] Furthermore, each of the several air supply holes of the vertical fire channel is provided with several fire channel air supply holes, and the number of fire channel air supply holes on each air supply hole cross section increases sequentially from top to bottom.

[0009] Furthermore, the vertical fire channel is a square column pipe, and the fire channel air supply pipe includes an arc-shaped pipe wall. The arc-shaped pipe wall and the inner wall of the vertical fire channel form an air supply channel, and the fire channel air supply holes set on the arc-shaped pipe wall have different orientations.

[0010] Furthermore, the fire duct air supply pipe includes a straight pipe wall, which forms an air supply channel with the inner wall of the vertical fire duct, and the straight pipe wall is provided with fire duct air supply holes.

[0011] Preferably, the fire duct air supply pipe has horizontal air supply openings with increasing width from top to bottom.

[0012] Preferably, the fire duct air supply pipe has a vertical air supply opening along the height direction on its pipe wall, and the vertical air supply opening is a vertical passage that is narrow at the top and wide at the bottom.

[0013] In the above structure, because a flue gas supply duct is installed in the vertical flue, combustion air is evenly supplied to all areas of the narrow space of the vertical flue. This ensures uniform mixing of combustible raw gas and combustion air in the narrow descending and ascending flues, forming a relatively balanced diffuse combustion in the descending and ascending flues. This not only avoids incomplete combustion but also prevents concentrated and intense combustion of raw gas and combustion air at the entrance of the vertical flue, thus suppressing the formation of nitrogen oxides. This not only improves the combustion efficiency of combustibles in the flue and makes heating more uniform but also shortens the coking time of the coke oven and effectively reduces the formation of nitrogen oxides during combustion, lowering the concentration of nitrogen oxides in the exhaust gas. Furthermore, the increasing air supply volume on the supply duct ensures that the combustible content in the high-temperature flue gas of the vertical flue matches the combustion air content, resulting in uniform and complete combustion, balancing the combustion speed and energy release intensity. The carbonization chamber flue structure of this utility model can not only shorten the width of the carbonization chamber and reduce the coke oven floor space without affecting the coke production, but also promote the uniform combustion of combustible gases in the flue, effectively suppress the generation of nitrogen oxides, and avoid the pollution of the coke oven to the environment. Attached Figure Description

[0014] The following detailed description of the low-NOx heat recovery coke oven vertical flue of this utility model, in conjunction with the accompanying drawings and specific embodiments, provides further insight.

[0015] Figure 1 This is a schematic diagram of the structure of a heat recovery coke oven with a vertical flue for low nitrogen oxide heat recovery, which applies this utility model.

[0016] Figure 2 yes Figure 1 A-A cross-section;

[0017] Figure 3 yes Figure 1 A schematic diagram of the vertical cross-sectional structure of a specific structure of the main wall of the intermediate carbonization chamber;

[0018] Figure 4 yes Figure 3 A schematic diagram of a specific structure in the B-B cross section;

[0019] Figure 5 yes Figure 3 Another specific structural diagram of the B-B cross section;

[0020] Figure 6 yes Figure 1 A schematic diagram of the vertical cross-section of another specific structure of the main wall of the intermediate carbonization chamber;

[0021] Figure 7 yes Figure 1 A schematic diagram of the vertical cross-section of another specific structure of the main wall of the carbonization chamber.

[0022] In the diagram, 1—carbonization chamber, 2—main wall of carbonization chamber, 3—vertical fire channel, 4—upper connecting fire channel, 5—fire channel air supply pipe, 6—lower connecting fire channel, 7—horizontal fire channel at the bottom of the chamber, 8—fire channel air supply hole, 9—horizontal air supply outlet, 10—vertical air supply outlet. Detailed Implementation

[0023] like Figure 1 , Figure 2 The illustrated low-NOx recovery coke oven vertical flue includes several parallel, vertically arranged carbonization chamber main walls 2. The tops of adjacent carbonization chamber main walls 2 are arched, and the arched tops and adjacent carbonization chamber main walls 2 enclose several perforated carbonization chambers 1. Each carbonization chamber 1 has a width B = 2m and a height H = 5m, forming a narrow and tall carbonization chamber structure. This ensures that the volume of the carbonization chamber remains unchanged, but the floor space occupied by the carbonization chamber is effectively reduced. Each carbonization chamber 1 has the same structure and dimensions. Preferably, the ratio of the width B to the height H of the carbonization chamber 1 is 2-4.

[0024] In each carbonization chamber main wall 2, several vertically arranged fire channels 3 are provided at equal intervals. Each fire channel 3 includes mutually vertical and parallel descending fire channels and ascending fire channels, which are alternately arranged in the carbonization chamber main wall 2. Alternatively, descending fire channels and ascending fire channels are alternately arranged in pairs or groups in the carbonization chamber main wall 2, and so on.

[0025] A horizontal fire channel 7 is provided at the bottom of the carbonization chamber 1. The upper end of the descending fire channel 3 is connected to the upper space of the carbonization chamber 1, and the lower end of the descending fire channel is connected to the horizontal fire channel 7 at the bottom of the chamber. The lower end of the ascending fire channel is connected to the horizontal fire channel 7 at the bottom of the chamber. A fire channel air supply pipe 5 is vertically installed in the cavity of the vertical fire channel 3.

[0026] like Figure 3 , Figure 4 As shown, the fire duct air supply pipe 5 adopts an arc-shaped tile-like structure. The arc-shaped tile-like pipe wall, together with the inner wall of the descending or ascending fire duct, forms an air supply channel. Several fire duct air supply holes 8 are arranged circumferentially on the tile-like pipe wall of the fire duct air supply pipe 5. The fire duct air supply holes 8 on the same horizontal cross-section have different air supply orientations to uniformly disperse the combustion flame direction. Several air supply hole cross-sections are equidistantly arranged on the fire duct air supply pipe 5. The total area of ​​each air supply hole cross-section increases sequentially from the top to the bottom of the fire duct air supply pipe 5, forming a structure where the air supply volume increases sequentially from top to bottom. In this embodiment, the fire duct air supply pipe 5 has five air supply hole cross-sections from top to bottom, and each air supply hole cross-section has one to five fire duct air supply holes 8 arranged radially in sequence. The fire duct air supply holes 8 are cylindrical holes, but can also be rectangular holes or other geometric cross-section holes, and the cross-sectional areas of each fire duct air supply hole 8 are approximately equal.

[0027] like Figure 5As shown, the difference between this embodiment and the above embodiments is that the fire duct air supply pipe 5 adopts a straight pipe wall structure. The straight pipe wall and the cavity wall of the vertical fire duct 3 form an air supply pipe, and a number of fire duct air supply holes 8 are provided on the straight pipe wall. One to five fire duct air supply holes 8 are arranged sequentially on the cross-section of each air supply hole in the straight pipe wall.

[0028] like Figure 6 As shown, this embodiment is similar to Figure 3 , Figure 4 The difference in the embodiment is that the fire duct air supply pipe 5 still adopts an arc-shaped tile-shaped pipe wall structure, and each air supply hole cross section is provided with an air supply horizontal opening 9. The width B of each air supply horizontal opening 9 increases sequentially from top to bottom, that is, B5>B4>B3>B2>B1.

[0029] like Figure 7 As shown, this embodiment is similar to Figure 3 , Figure 4 The difference in the embodiment is that a vertical air supply opening 10 is provided on the pipe wall of the fire duct air supply pipe 5. The air supply opening 10 is an air outlet with an isosceles trapezoidal cross section that is narrow at the top and wide at the bottom.

[0030] The above are some preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make improvements and substitutions to the technical solutions described in the foregoing embodiments. Such substitutions and improvements that violate the spirit and principles of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A vertical flue for a low-NOx heat recovery coke oven, comprising a carbonization chamber main wall (2), wherein a carbonization chamber (1) is located between two adjacent carbonization chamber main walls (2), characterized in that: The bottom of the carbonization chamber (1) is provided with a horizontal fire channel (7), and a vertical fire channel (3) is provided in the main wall (2) of the carbonization chamber. A fire channel air supply pipe (5) is provided in the vertical fire channel (3) along the height direction. The air supply volume on the fire channel air supply pipe (5) increases sequentially from top to bottom.

2. The low-NOx heat recovery coke oven vertical flue according to claim 1, characterized in that: The vertical fire channel (3) includes a descending fire channel and an ascending fire channel installed in the main wall (2) of the carbonization chamber. The upper end of the descending fire channel is connected to the upper space of the carbonization chamber (1), and the lower end of the descending fire channel leads to the horizontal fire channel (7) at the bottom of the chamber. The lower end of the ascending fire channel is connected to the horizontal fire channel (7) at the bottom of the chamber.

3. The low-NOx heat recovery coke oven vertical flue according to claim 1, characterized in that: The ratio of the width B to the height h of the carbonization chamber (1) is 1:(2-4).

4. The low-NOx heat recovery coke oven vertical flue according to claim 1, 2 or 3, characterized in that: The vertical fire channel (3) has several fire channel air supply holes (8) on its cross-section, and the number of fire channel air supply holes (8) on each cross-section increases sequentially from top to bottom.

5. The low-NOx heat recovery coke oven vertical flue according to claim 4, characterized in that: The fire channel (3) is a square column tube, and the fire channel air supply pipe (5) includes an arc-shaped pipe wall. The arc-shaped pipe wall and the inner wall of the fire channel (3) form an air supply channel, and the fire channel air supply holes (8) set on the arc-shaped pipe wall have different orientations.

6. The low-NOx heat recovery coke oven vertical flue according to claim 4, characterized in that: The fire duct air supply pipe (5) includes a straight pipe wall, which forms an air supply channel with the inner wall of the vertical fire duct (3), and the straight pipe wall is provided with a fire duct air supply hole (8).

7. The low-NOx heat recovery coke oven vertical flue according to claim 1, 2 or 3, characterized in that: The fire duct air supply pipe (5) has air supply horizontal openings (9) with increasing width from top to bottom.

8. The low-NOx heat recovery coke oven vertical flue according to claim 1, 2 or 3, characterized in that: The fire duct air supply pipe (5) has an air supply vertical opening (10) along the height direction on the pipe wall. The air supply vertical opening (10) is a vertical opening that is narrow at the top and wide at the bottom.

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