Fire pumping device and combustor

Abstract

The utility model provides a fire extraction device and a combustor, and relates to the technical field of pulverized coal combustion equipment, the fire extraction device comprises a first end cover; the fire extraction cylinder is provided with a first inclined hole penetrating through the fire extraction cylinder, the first inclined hole is provided with an air nozzle, and the outlet direction of the nozzle is consistent with the fire extraction direction; the sleeve is coaxially arranged on the outer side of the fire extraction barrel, and an air inlet hole is formed in the sleeve; the second end cover is a hollow cylinder, an inner hole of the hollow cylinder is a trumpet-shaped through hole with an outward opening, the two ends of the fire extraction barrel and the two ends of the sleeve are fixed to the second end cover and the second end cover respectively, and a compressed air cavity is formed between the inner wall of the sleeve and the outer wall of the fire extraction barrel. The fire pumping device can pump part of flames combusted at the front end of the combustor back to the rear end of the combustor, stable combustion of pulverized coal in the combustor is achieved, and the igniter does not need to work continuously.

Description

Technical Field

[0001] The utility model relates to the technical field of coal powder combustion equipment, in particular to a fire extraction device and a burner. Background Art

[0002] Coal is the most abundant and widely distributed fossil fuel on earth. It has a wide range of uses and is also an important raw material for metallurgy and chemical industries, mainly used for combustion, coking, gasification, low-temperature distillation, hydrogenation liquefaction, etc.

[0003] The combustion stability of pulverized coal boiler is the basic premise to ensure stable combustion in the furnace and safe and normal operation of the boiler. However, for many pulverized coal boilers, combustion stability is a common problem, especially when running at low load.

[0004] The main method currently used for low-load stable combustion of pulverized coal boilers is high-temperature plasma combustion-assisted combustion, but the plasma combustion-assisted power is limited, the plasma igniter works for a long time, and there is also the problem of short design life of the cathode head, which needs frequent replacement. Otherwise, failure may occur at any time, leading to boiler extinguishing. After the failure, not only will the stable combustion effect be lost, but the safe operation of the equipment will also be affected. Utility Model Content

[0005] The utility model aims to provide a fire extraction device and a burner to solve the technical problem in the prior art that pulverized coal cannot burn stably when running at low load.

[0006] The fire extraction device provided by the utility model is characterized in that it comprises: a first end cover, the first end cover is a frustum, and a cylindrical through hole is provided in the center of the frustum; a fire extraction tube, the fire extraction tube is provided with a first inclined hole that penetrates the tube wall of the fire extraction tube, the first inclined hole faces the middle part of the fire extraction tube, the axis of the first inclined hole intersects with the axial direction of the fire extraction tube at one point, the first inclined holes are evenly distributed along the barrel wall of the fire extraction tube, each of the first inclined holes is provided with at least one nozzle, the outlet direction of the nozzle is consistent with the fire extraction direction, one end of the fire extraction tube is fixedly connected to the bottom surface of the frustum, the inner hole of the fire extraction tube has the same diameter as the cylindrical through hole and The axes coincide; a sleeve, the sleeve is coaxially arranged on the outside of the fire extraction tube, one end of the sleeve is fixedly connected to the bottom surface of the cone, and the sleeve is provided with an air inlet hole; a second end cover, the second end cover is arranged at the fire extraction end of the fire extraction device, the second end cover is a hollow cylinder, the inner hole of the hollow cylinder is a trumpet-shaped through hole opening outward, the minimum bottom diameter of the trumpet-shaped through hole is larger than the inner diameter of the fire extraction tube, the other end of the fire extraction tube and the other end of the sleeve are fixedly connected to the second end cover, and the axis of the hollow cylinder coincides with the axis of the fire extraction tube, and a compressed air cavity is formed between the inner wall of the sleeve and the outer wall of the fire extraction tube.

[0007] Furthermore, a V-shaped groove is concentrically provided on the outer wall of the fire extractor, the V-shaped groove is close to the fire extraction end of the fire extractor, the angle of the V-shaped groove is 90°-110°, the depth of the V-shaped groove is 1 / 3-1 / 2 of the thickness of the fire extractor wall, and the first inclined hole is arranged on the inclined surface of the V-shaped groove away from the fire extraction end of the fire extractor.

[0008] Furthermore, the angle between the first inclined hole and the axis of the fire extraction tube is 20°-70°.

[0009] Furthermore, a concave cavity is provided on the bottom surface of the truncated cone, and the concave cavity is connected with the compressed air cavity. A plurality of second inclined holes are provided between the bottom surface of the concave cavity and the top surface of the truncated cone. The axis of the second inclined hole intersects with the axis of the truncated cone at one point. At least one nozzle is provided on the second inclined hole, and the outlet direction of the nozzle is consistent with the ignition direction.

[0010] Furthermore, the angle between the second inclined hole and the axis of the frustum is 10°-60°.

[0011] Furthermore, the top surface of the truncated cone is transitionally connected to the side surface arc.

[0012] Furthermore, each of the first inclined holes is provided with two air nozzles.

[0013] On the other hand, the utility model provides a burner, which includes the fire extraction device, igniter and combustion tube as described in any one of the above items, the ignition position of the igniter is located at the inlet of the first end cover of the fire extraction device, and the fire extraction device is connected to the primary air inlet of the coal powder; the fire extraction device is arranged in the combustion tube.

[0014] The beneficial effects brought by the technical solution provided by the embodiment of the utility model include:

[0015] (1) Compressed air is used as the power source of the fire extraction device to extract part of the flame burning at the front end of the burner back to the rear end of the burner to ignite other coal powder in the burner, thereby achieving stable combustion of coal powder in the burner without the need for the igniter to work continuously.

[0016] (2) The igniter does not need to work continuously, which reduces energy consumption and is beneficial to sustainable development and environmental protection.

[0017] (3) The igniter does not need to work continuously, which reduces the replacement frequency of the igniter, reduces the boiler combustion cost, and improves production efficiency and market competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A front view of a fire extraction device provided by an embodiment of the utility model;

[0020] Figure 2 For the utility model embodiment Figure 1 Section view along AA;

[0021] Figure numerals: 1. first end cover; 11. cylindrical through hole; 12. concave cavity; 13. second inclined hole; 2. spark extractor; 21. first inclined hole; 22. nozzle; 3. sleeve; 31. air inlet; 4. second end cover; 41. trumpet-shaped through hole; 5. compressed air cavity. DETAILED DESCRIPTION

[0022] The technical solution of the utility model will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model. Therefore, the following detailed description of the embodiments of the utility model provided in the drawings is not intended to limit the scope of the utility model for which protection is sought, but merely represents the selected embodiments of the utility model. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the utility model.

[0024] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" 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 a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0025] In the present utility model, unless otherwise clearly specified and limited, the first feature being above or below the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. Moreover, the first feature being above, above, and above the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being below, below, and below the second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0026] The utility model provides a fire extraction device, which is characterized in that: Figure 1 and Figure 2 As shown, it comprises: a first end cover 1, which is a truncated cone, and a cylindrical through hole 11 is provided at the center of the truncated cone; a fire extraction tube 2, which is provided with a first inclined hole 21 penetrating the barrel wall of the fire extraction tube 2, and the first inclined hole 21 faces the middle of the fire extraction tube 2, and the axis of the first inclined hole 21 intersects with the axial direction of the fire extraction tube 2 at one point, and the first inclined holes 21 are evenly distributed along the barrel wall of the fire extraction tube 2, and each of the first inclined holes 21 is provided with at least one nozzle 22, and the outlet direction of the nozzle 22 is consistent with the direction of fire extraction, one end of the fire extraction tube 2 is fixedly connected to the bottom surface of the truncated cone, and the inner hole of the fire extraction tube 2 has the same aperture as the cylindrical through hole 11, and the axis coincides; A sleeve 3, wherein the sleeve 3 is coaxially arranged on the outside of the fire extraction tube 2, one end of the sleeve 3 is fixedly connected to the bottom surface of the cone, and an air inlet hole 31 is provided on the sleeve 3; a second end cover 4, wherein the second end cover 4 is arranged at the fire extraction end of the fire extraction device, and the second end cover 4 is a hollow cylinder, and the inner hole of the hollow cylinder is a trumpet-shaped through hole 41 opening outward, and the minimum bottom diameter of the trumpet-shaped through hole 41 is larger than the inner diameter of the fire extraction tube 2, the other end of the fire extraction tube 2 and the other end of the sleeve 3 are fixedly connected to the second end cover 4, and the axis of the hollow cylinder coincides with the axis of the fire extraction tube 2, and a compressed air cavity 5 is formed between the inner wall of the sleeve 3 and the outer wall of the fire extraction tube 2.

[0027] Through the above-mentioned fire extraction device, the compressed air in the compressed air cavity 5 is quickly ejected forward through the nozzle 22, thereby forming a negative pressure area in the fire extraction tube 2 relative to the second end cover 4, and then part of the flame at the second end cover 4 is drawn back into the fire extraction tube 2 and ejected from the cylindrical through hole 11 of the first end cover 1 along with the airflow of the compressed air, and contacts with the coal powder at the rear end of the burner to achieve ignition. It should be noted here that the primary air of the coal powder passes through the opening of the cylindrical through hole 11 of the first end cover 1. Under normal circumstances, the fire of the burner is ejected from the rear end to the front end, and the coal powder entering the rear end is ignited by the flame extracted by the fire extraction device without the need for ignition by an igniter.

[0028] Setting the first end cover 1 as a truncated cone structure with a cylindrical through hole 11 is helpful to achieve effective diversion of the coal powder at the front end of the burner. A part of the coal powder is diverted to the side wall of the cone and burned in the combustion tube outside the fire extraction tube 2, and a part of the coal powder is concentrated in the central hole of the fire extraction device and fully mixed with the flame from the fire extraction tube 2 to ignite the coal powder; the first inclined holes 21 are evenly distributed along the tube wall, so that the flame in the fire extraction device can be evenly distributed along the fire extraction tube; the air inlet hole 31 on the sleeve 3 is used to connect an air compressor or other device that can provide compressed air, and the trumpet-shaped opening of the second end cover 4 can draw the flame at the front end of the burner back to the fire extraction tube 2 to the greatest extent.

[0029] The second oblique hole 13 on the cylinder wall of the fire extraction tube 2 can be directly arranged on the cylinder wall, or a groove can be provided on the cylinder wall and on the corresponding side of the groove.

[0030] Preferably, a V-shaped groove is concentrically provided on the outer wall of the fire extractor 2, the V-shaped groove is close to the fire extraction end of the fire extractor 2, the angle of the V-shaped groove is 90°-110°, the depth of the V-shaped groove is 1 / 3-1 / 2 of the thickness of the wall of the fire extractor 2, and the first inclined hole 21 is arranged on the inclined surface of the V-shaped groove away from the fire extraction end of the fire extractor 2.

[0031] The first inclined hole 21 is arranged on the inclined surface of the V-shaped groove. On the one hand, the processing depth of the first inclined hole 21 can be reduced. The inclined hole is easier to position and process on the inclined surface of the V-shaped groove, which reduces the processing difficulty and saves the processing cost. On the other hand, the setting of the V-shaped groove can alleviate the deformation of the combustion tube caused by heat, and the V-shaped groove can absorb part of the thermal expansion deformation. The angle of the V-shaped groove is set to 90°-110°. When it is greater than 90°, the two sides of the V-shaped groove interfere with each other when processing the first inclined hole 21. When it is less than 110°, the width of the V-shaped groove is prevented from being too wide, which affects the processing efficiency. The depth of the V-shaped groove is 1 / 3-1 / 2 of the thickness of the wall of the fire extraction tube 2. While reducing the processing difficulty, the rigidity of the combustion tube is ensured at the same time.

[0032] Specifically, the angle between the first inclined hole 21 and the axis of the fire extractor 2 is 20°-70°.

[0033] The angle between the first inclined hole 21 and the axis of the fire extraction tube 2 is set to 20°-70°. Under the same conditions, a technical effect of higher fire extraction efficiency can be achieved.

[0034] Specifically, Figure 2 As shown, a concave cavity 12 is provided on the bottom surface of the truncated cone, and the concave cavity 12 is connected with the compressed air cavity 5. A plurality of penetrating second inclined holes 13 are provided between the bottom surface of the concave cavity 12 and the top surface of the truncated cone. The axis of the second inclined hole 13 intersects with the axis of the truncated cone at one point. At least one nozzle 22 is provided on the second inclined hole 13, and the outlet direction of the nozzle 22 is consistent with the ignition direction.

[0035] The setting of the concave cavity 12 can increase the capacity of compressed air, increase the overall heat exchange area of ​​the fire extraction device, and facilitate the processing of the second inclined hole 13; a second inclined hole 13 is provided on the bottom surface of the concave cavity 12, and a compressed air nozzle 22 is provided on the second inclined hole 13, and the compressed air is quickly ejected from the second inclined hole 13, and a negative pressure is formed at the first end cover 1 relative to the outlet of the first inclined hole 21, which is more conducive to improving the overall suction efficiency of the fire extraction tube 2; in addition, the compressed air ejected from the second inclined hole 13 can be more fully mixed with the oncoming coal powder, and can provide enough oxygen for the coal powder to burn.

[0036] It can be understood that the above technical effect can be achieved as long as the injection position of the second inclined hole 13 is set between the bottom surface of the cavity 12 and the top surface of the truncated cone.

[0037] Preferably, the angle between the second inclined hole 13 and the axis of the truncated cone is 10°-60°.

[0038] Setting the included angle between the second inclined hole 13 and the axis of the truncated cone to 10°-60° is more conducive to improving the suction rate.

[0039] Specifically, Figure 2 As shown, the top surface of the frustum is transitionally connected to the side arc.

[0040] The transition connection between the top surface of the truncated cone and the side arc can not only prevent the generation of weak surfaces at the corners, but also reduce stress concentration, and avoid the generation of shrinkage holes, cracks and other undesirable phenomena, while ensuring that the coal powder is subject to less resistance at the first end cover 1 of the fire extraction device.

[0041] Specifically, each of the first inclined holes 21 is provided with two air nozzles 22 .

[0042] The arrangement of the two air nozzles 22 can quickly spray more gas, forming a stronger negative pressure at the rear end of the nozzle 22, which is more conducive to the extraction of flames by the fire extractor 2.

[0043] The fixed connection between the fire extractor 2, the first end cover 1, the second end cover 4 and the sleeve 3 can be any connection as long as it can be firmly connected and form the compressed air cavity 5. Preferably, the fixed connection is welding.

[0044] The welding process is beneficial to saving metal materials, reducing structural weight and having good economic benefits; welding is easy to mechanize and automate, saving processing costs; the welded structure has high strength and the joints have better sealing.

[0045] As another aspect of the utility model, the utility model also provides a burner, which includes the fire extraction device, igniter and combustion tube as described in any one of the above items, the ignition position of the igniter is located at the inlet of the first end cover 1 of the fire extraction device, and the fire extraction device is connected to the primary air inlet of the coal powder; the fire extraction device is arranged in the combustion tube.

[0046] The primary air of coal powder is introduced into the combustion tube, and the igniter ignites the coal powder in the combustion tube, and the coal powder burns in the combustion tube, and the flame is pushed from the rear end to the front end of the burner; in the fire extraction device provided by the utility model, compressed air is quickly ejected from the nozzle, and negative pressure is formed in the fire extraction tube 2, then part of the flame at the rear end of the combustion tube will be drawn back to the front end of the combustion tube through the fire extraction tube 2 to ignite the primary air of coal powder that has just entered the combustion tube, thereby realizing self-sustaining stable combustion of the coal powder in the combustion tube, and the igniter does not need to work continuously; the fire extraction efficiency can be adjusted by adjusting the flow rate of compressed air, thereby realizing the adjustment of self-sustaining stable combustion, reducing the ignition power and saving energy; in addition, the center of the fire extraction device is set to be a through hole, so when the fire extraction device is not needed in the burner, the coal powder can also pass through the through hole in the center of the fire extraction device without affecting the normal operation of the burner.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A fire extraction device, characterized in that: include: A first end cover, wherein the first end cover is a truncated cone, and a cylindrical through hole is provided at the center of the truncated cone; A fire extraction tube, wherein the fire extraction tube is provided with a first oblique hole penetrating through the tube wall of the fire extraction tube, the first oblique hole faces the middle of the fire extraction tube, the axis of the first oblique hole intersects with the axial direction of the fire extraction tube at a point, the first oblique holes are evenly distributed along the tube wall of the fire extraction tube, each of the first oblique holes is provided with at least one nozzle, the outlet direction of the nozzle is consistent with the direction of fire extraction, one end of the fire extraction tube is fixedly connected to the bottom surface of the truncated cone, the inner hole of the fire extraction tube has the same diameter as the cylindrical through hole and the axis coincides; A sleeve, wherein the sleeve is coaxially arranged on the outside of the fire extraction cylinder, one end of the sleeve is fixedly connected to the bottom surface of the truncated cone, and an air inlet hole is provided on the sleeve; The second end cover is arranged at the fire extraction end of the fire extraction device, the second end cover is a hollow cylinder, the inner hole of the hollow cylinder is a trumpet-shaped through hole opening outward, the minimum bottom diameter of the trumpet-shaped through hole is larger than the inner diameter of the fire extraction tube, the other end of the fire extraction tube and the other end of the sleeve are fixedly connected to the second end cover, and the axis of the hollow cylinder coincides with the axis of the fire extraction tube, and a compressed air cavity is formed between the inner wall of the sleeve and the outer wall of the fire extraction tube.

2. The fire extraction device according to claim 1, characterized in that: A V-shaped groove is concentrically provided on the outer wall of the fire extractor, the V-shaped groove is close to the fire extraction end of the fire extractor, the angle of the V-shaped groove is 90°-110°, the depth of the V-shaped groove is 1 / 3-1 / 2 of the thickness of the fire extractor wall, and the first inclined hole is arranged on the inclined surface of the V-shaped groove away from the fire extraction end of the fire extractor.

3. The fire extraction device according to claim 1 or 2, characterized in that: The angle between the first inclined hole and the axis of the fire extraction tube is 20°-70°.

4. The fire extraction device according to claim 1, characterized in that: A concave cavity is provided on the bottom surface of the truncated cone, and the concave cavity is connected with the compressed air cavity. A plurality of second inclined holes are provided between the bottom surface of the concave cavity and the top surface of the truncated cone. The axes of the second inclined holes intersect with the axis of the truncated cone at one point. At least one nozzle is provided on the second inclined hole, and the outlet direction of the nozzle is consistent with the ignition direction.

5. The fire extraction device according to claim 4, characterized in that: The included angle between the second inclined hole and the axis of the frustum is 10°-60°.

6. The fire extraction device according to claim 1, characterized in that: The top surface of the truncated cone is transitionally connected to the side surface circular arc.

7. The fire extraction device according to claim 1, characterized in that: Each of the first inclined holes is provided with two air nozzles.

8. A burner, characterized in that: The burner comprises the fire extraction device, igniter and combustion tube as described in any one of claims 1-7, the ignition position of the igniter is located at the inlet of the first end cover of the fire extraction device, the fire extraction device is connected to the primary air inlet of the coal powder; the fire extraction device is arranged in the combustion tube.

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