Annular jet type pulverized coal concentration adjusting device

Abstract

The utility model discloses an annular jet type pulverized coal concentration adjusting device which comprises a pulverized coal pipeline. An air chamber is coaxially and fixedly connected outside the pulverized coal pipeline, the air chamber is fixedly connected with an air supply pipe, the windward side of the front end of the air chamber opposite to the airflow direction of primary air powder in the pulverized coal pipeline is a conical surface, at least two jet flow nozzles are evenly distributed on the circumference of the side wall of the pulverized coal pipeline in front of the air chamber, and the conical surface of the air chamber is connected to the axial front sides of the jet flow nozzles. An inclined flow guide plate is fixedly connected to the axial rear side of the jet flow nozzle, a certain angle a is formed between the incident angle of the jet flow nozzle formed by the conical surface of the air chamber and the flow guide plate and the central axis of the pulverized coal pipeline, and a is larger than 0 degree and smaller than 90 degrees; the utility model not only has the advantage of good adjusting effect, but also has a non-mechanical adjusting structure, is small in abrasion, can avoid jamming, and can ensure the stability of the adjusting effect.

Description

Technical Field

[0001] The utility model relates to a pulverized coal concentration regulating device, in particular to an annular jet type pulverized coal concentration regulating device for a pulverized coal boiler coal mill. Background Art

[0002] For pulverized coal boilers, it is crucial to balance the power of each burner by adjusting the pulverizing system. The power of the burner depends on the amount of pulverized coal in each pulverized coal inlet pipe. Since the pulverized coal pipelines on the pulverizer are connected to different locations of the boiler, the direction and length of the pipelines are also different. Due to this difference, the resistance of the pulverized coal pipeline to the air-pulverized mixture is also different, which further affects the flow rate, resulting in large deviations in the amount of pulverized coal in each pulverized coal pipeline. Large deviations in pulverized coal amount will cause the following problems in boiler operation:

[0003] 1. The thermal deviation of the heating surface is large, and the tube wall is prone to overheating;

[0004] 2. The heat load in the furnace is uneven, and local coking occurs on the water-cooled wall;

[0005] 3. Coal powder deposition in the primary air horizontal pipeline can easily lead to pipe blockage and cause the corresponding burner to burn out;

[0006] 4. Furnace outlet NO x Uneven distribution leads to NO entering the denitrification device x The concentration field is uneven, the ammonia escape amount of the denitrification device is also uneven, and there is a risk of ammonium bisulfate blockage in the air preheater;

[0007] 5. If the burners with a large amount of powder are located on the two side walls, the O2 in the two side wall areas will be extremely low and the CO will be extremely high, increasing the probability of high temperature corrosion of the side wall water-cooled wall.

[0008] Currently, the commonly used coal powder concentration adjustment devices are mechanical adjustment mechanisms such as adjustable shrinkage holes or shutter-type coal powder distributors. Not only are the adjustment effects limited, but they also have defects such as easy wear, sticking, and inconvenient adjustment, which affect their service life and are difficult to achieve remote operation and automatic control. Summary of the invention

[0009] The purpose of the utility model is to provide an annular jet type coal powder concentration regulating device in view of the above-mentioned deficiencies in the prior art, which not only has the advantage of good regulating effect, but also is a non-mechanical regulating structure with little wear and can avoid jamming, thereby ensuring the stability of the regulating effect.

[0010] In order to achieve the above-mentioned purpose, the utility model provides an annular jet-type coal powder concentration regulating device, including a coal powder pipeline; characterized in that: an air chamber is coaxially fixedly connected outside the coal powder pipeline, the air chamber is fixedly connected to the air supply pipe, the front end windward surface of the air chamber relative to the primary air and powder airflow direction in the coal powder pipeline is a conical surface, and the side wall of the coal powder pipeline in front of the air chamber is provided with at least two jet nozzles evenly distributed on the circumference, the conical surface of the air chamber is connected to the axial front side of the jet nozzle, and the axial rear side of the jet nozzle is fixedly connected with an inclined guide plate, and the incident angle of the jet nozzle formed by the conical surface of the air chamber and the guide plate is at a certain angle a with the central axis of the coal powder pipeline, and 0°<a<90°.

[0011] When the utility model is used, high-pressure air is fed into the wind chamber through the air supply pipe, and the high-pressure air in the wind chamber forms regulated wind through each jet nozzle, and the regulated wind is sprayed into the coal powder pipeline. Since the spray direction of the regulated wind is obliquely opposite to the primary air and powder airflow direction in the coal powder pipeline, the resistance of the primary air and powder can be increased and the flow field can be disturbed, thereby achieving the purpose of reducing the amount of coal powder in the coal powder pipeline, thereby adjusting the coal powder concentration; when the utility model is used for multiple coal powder pipelines, the powder amount distribution of each coal powder pipeline can be more uniform; the device not only has the advantage of good regulating effect, but also each component is fixedly connected, and only high-pressure air needs to be introduced through the air supply pipe. It is a non-mechanical regulating structure, with little wear and can avoid jamming, which can ensure the stability of the regulating effect and extend the service life;

[0012] As a further improvement of the utility model, the radial inner end of the conical surface and the radial inner end of the guide plate are both flush with the axial sides of the jet nozzle on the side wall of the pulverized coal pipeline to form a flush nozzle;

[0013] As a further improvement of the utility model, the radial inner end of the conical surface and the radial inner end of the guide plate are both located radially inside the jet nozzle on the side wall of the pulverized coal pipeline, and the radial outer end of the guide plate is located in the wind chamber; both sides of the nozzle can be extended;

[0014] As a further improvement of the utility model, the radial inner end of the conical surface is flush with the axial front side of the jet nozzle on the side wall of the pulverized coal pipeline, the radial inner end of the guide plate is located radially inside the jet nozzle on the side wall of the pulverized coal pipeline, and the radial outer end of the guide plate is located in the wind chamber; a single-side extension nozzle can be formed;

[0015] The above three types of nozzles have increasing effects on regulating the pulverized coal concentration;

[0016] As a further improvement of the utility model, the inner wall of the pulverized coal pipeline, the inner wall of the cone surface and the guide plate are all provided with a wear-resistant material spray coating or patch; or the pulverized coal pipeline, the cone surface and the guide plate are integrally cast with a wear-resistant material; wear resistance can be improved;

[0017] In summary, the utility model not only has the advantage of good adjustment effect, but also is a non-mechanical adjustment structure, has little wear and can avoid jamming, thereby ensuring the stability of the adjustment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional diagram of an embodiment of the utility model.

[0019] Figure 2 for Figure 1 Schematic diagram of the cross-section of each jet nozzle in the pulverized coal pipeline.

[0020] Figure 3 for Figure 1 Front view of the first embodiment of the middle jet nozzle.

[0021] Figure 4 for Figure 1 Front view of the second embodiment of the middle jet nozzle.

[0022] Figure 5 for Figure 1 Front view of the third embodiment of the middle jet nozzle. DETAILED DESCRIPTION

[0023] The utility model is further described below in conjunction with the accompanying drawings.

[0024] like Figure 1 to Figure 2 As shown, an annular jet type coal powder concentration regulating device of this embodiment comprises a coal powder pipeline 1, a wind chamber 2 coaxially welded and fixedly connected to the outside of the coal powder pipeline 1, the wind chamber 2 is welded and fixedly connected to the air supply pipe 3, the front windward surface of the wind chamber relative to the primary air and powder airflow direction in the coal powder pipeline 1 is a conical surface 4, and the side wall of the coal powder pipeline 1 in front of the wind chamber 1 is provided with three jet nozzles 5 evenly distributed on the circumference, the conical surface 4 of the wind chamber 1 is connected to the axial front side of the jet nozzle 5, and the axial rear side of the jet nozzle 5 is fixedly connected with an inclined guide plate 6, and the incident angle of the jet nozzle formed by the conical surface 4 of the wind chamber and the guide plate 6 is at a certain angle a with the central axis of the coal powder pipeline 1, and 0°<a<90°.

[0025] like Figure 3 As shown, the radial inner end of the conical surface 4 and the radial inner end of the guide plate 6 are flush with the axial sides of the jet nozzle 5 on the side wall of the pulverized coal pipeline 1, forming a flush nozzle; Figure 4 As shown, the radial inner end of the conical surface 4 and the radial inner end of the guide plate 6 are both located radially inside the jet nozzle 5 on the side wall of the pulverized coal pipeline 1, and the radial outer end of the guide plate 6 is located in the wind chamber 2; both sides of the extended nozzle can be formed; as shown Figure 5As shown, the radial inner end of the conical surface 4 is flush with the axial front side of the jet nozzle 5 on the side wall of the pulverized coal pipeline 1, the radial inner end of the guide plate 6 is located radially inside the jet nozzle 5 on the side wall of the pulverized coal pipeline 1, and the radial outer end of the guide plate 6 is located in the wind chamber 2; a single-side extension nozzle can be formed;

[0026] When the utility model is used, high-pressure air is fed into the air chamber 2 through the air supply pipe 3, and the high-pressure air in the air chamber 2 forms regulated air through each jet nozzle 5, and the regulated air is injected into the coal powder pipeline 1. Since the injection direction of the regulated air is obliquely opposite to the primary air and powder airflow direction in the coal powder pipeline 1, the resistance of the primary air and powder can be increased and the flow field can be disturbed, thereby achieving the purpose of reducing the amount of coal powder in the coal powder pipeline, thereby adjusting the coal powder concentration; when the utility model is used for multiple coal powder pipelines, the powder amount distribution of each coal powder pipeline can be more uniform; the device not only has the advantage of good regulating effect, but also each component is fixedly connected, and only high-pressure air needs to be introduced through the air supply pipe 3. It is a non-mechanical regulating structure, with little wear and can avoid jamming, which can ensure the stability of the regulating effect and extend the service life;

[0027] Among the three types of jet nozzles, since both the double-side extension nozzle and the single-side extension nozzle have guide plates, the front side of the single-side extension nozzle is perpendicular to the flow direction of the pulverized coal, and the injection area is larger, the pulverized coal concentration adjustment effects of the three types of jet nozzles increase in turn;

[0028] The inner wall of the pulverized coal pipeline 1, the inner wall of the cone surface 4 and the guide plate 6 are all provided with a wear-resistant material spray coating or patch; or the pulverized coal pipeline 1, the cone surface 4 and the guide plate 6 are integrally cast with a wear-resistant material; both can improve the wear resistance;

[0029] The number of the jet nozzles 5 of the utility model can be changed, the corresponding nozzle gaps also change, the flow area of ​​the jet nozzles 5 accounts for the proportion of the total area of ​​the circular ring where they are located, and the proportion is 1 / n (n=2, 3, 4, 5, 6, 7, 8, 9, 10...), and the outlet wind speed of the jet nozzle is higher than the wind speed of the gas phase flow in the coal powder pipeline; it is illustrated by the above embodiments, but it should be understood that the above embodiments are only for the purpose of example and description, and are not intended to limit the utility model to the scope of the described embodiments.

Claims

1. An annular jet type pulverized coal concentration regulating device, comprising a pulverized coal pipeline; characterized in that: An air chamber is coaxially fixedly connected outside the coal powder pipeline, the air chamber is fixedly connected to the air supply pipe, the front windward surface of the air chamber relative to the primary air and powder airflow direction in the coal powder pipeline is a conical surface, and the side wall of the coal powder pipeline in front of the air chamber is provided with at least two jet nozzles evenly distributed on the circumference, the conical surface of the air chamber is connected to the axial front side of the jet nozzle, and the axial rear side of the jet nozzle is fixedly connected with an inclined guide plate, the incident angle of the jet nozzle formed by the conical surface of the air chamber and the guide plate forms a certain angle a with the central axis of the coal powder pipeline, and 0°<a<90°.

2. The annular jet type pulverized coal concentration regulating device according to claim 1, characterized in that: The radial inner end of the conical surface and the radial inner end of the guide plate are both flush with the axial sides of the jet nozzle on the side wall of the pulverized coal pipeline.

3. The annular jet type pulverized coal concentration regulating device according to claim 1, characterized in that: The radial inner end of the conical surface and the radial inner end of the guide plate are both located radially inside the jet nozzle on the side wall of the pulverized coal pipeline, and the radial outer end of the guide plate is located in the wind chamber.

4. The annular jet type pulverized coal concentration regulating device according to claim 1, characterized in that: The radial inner end of the conical surface is flush with the axial front side of the jet nozzle on the side wall of the coal powder pipeline, the radial inner end of the guide plate is located radially inside the jet nozzle on the side wall of the coal powder pipeline, and the radial outer end of the guide plate is located in the wind chamber.

5. The annular jet type coal powder concentration regulating device according to any one of claims 1 to 4, characterized in that: The inner wall of the pulverized coal pipeline, the inner wall of the cone surface and the guide plate are all provided with a wear-resistant material spray coating or patch.

6. The annular jet type pulverized coal concentration regulating device according to any one of claims 1 to 4, characterized in that: The pulverized coal pipeline, cone surface and guide plate are integrally cast with wear-resistant materials.

Images