Secondary air device and biomass boiler

Abstract

The utility model belongs to the technical field of biomass boilers, and particularly relates to a secondary air device and a biomass boiler. The secondary air device comprises at least one pair of secondary air pipes, the pair of secondary air pipes are symmetrically arranged on the two sides of the combustion area, the secondary air pipes are provided with at least one air spraying pipe at intervals in the length direction of the secondary air pipes, and air enters the air spraying pipes through the secondary air pipes and then is sprayed to the combustion area; extension lines of outlets of the gas ejector pipes are tangent to the same cylinder in the combustion area, and gas ejected by the gas ejector pipes can drive materials in the combustion area to rotate in the same circumferential direction in the same direction. The extension lines of the outlets of the gas ejector pipes are tangent to the same cylinder in the combustion area, so that gas ejected by the gas ejector pipes can drive materials in the combustion area to rotate in the same circumferential direction in the same direction, the staying time of the materials in the combustion area can be prolonged through centrifugal force generated by rotation, and combustion is more sufficient.

Description

Technical Field

[0001] The utility model belongs to the technical field of biomass boilers, and in particular relates to a secondary air device and a biomass boiler. Background Art

[0002] A biomass boiler is a type of boiler equipment that uses biomass as fuel, usually used to generate heat or steam to supply industrial production or heating needs.

[0003] Secondary air device is a common device in industrial production process, mainly used in industrial boilers and kilns. It is also widely used in biomass boilers. Its main functions are as follows:

[0004] 1. Increase fuel combustion efficiency: The secondary air device can introduce additional air into the combustion chamber to promote full combustion of the fuel and improve thermal efficiency.

[0005] 2. Reduce pollutant emissions: The secondary air device can increase the oxygen supply for combustion, which is beneficial to reduce the emission of harmful substances such as carbon monoxide and unburned hydrocarbons in the flue gas.

[0006] 3. Improve combustion state: Secondary air can change the airflow distribution in the combustion chamber, so that the fuel can be burned more fully and achieve a stable combustion state.

[0007] 4. Improve boiler thermal efficiency: The introduction of secondary air can improve the thermal efficiency of the boiler and reduce fuel consumption.

[0008] When the existing secondary air device is used on the biomass boiler, it only adopts a single blowing or counter-blowing method. Although it can increase the contact area between air and biomass particles, the secondary air device in the prior art can improve the combustion efficiency. However, the secondary air device of the existing biomass boiler does not take into account the light weight characteristics of biomass fuel. Therefore, its combustion efficiency still has room for further improvement. Utility Model Content

[0009] The technical problem to be solved by the present invention is to provide a secondary air device that utilizes the light weight of biomass pellets to increase the time the biomass pellets stay in the combustion zone, thereby enabling more complete combustion of the biomass fuel. The present invention also provides a biomass boiler that utilizes the secondary air device.

[0010] The technical solution proposed by the utility model is:

[0011] In a first aspect, the present invention provides a secondary air device comprising at least one pair of secondary air ducts, the pair of secondary air ducts being symmetrically arranged on either side of a combustion zone, the secondary air ducts being provided with at least one injection pipe spaced apart along their lengths, and gas passing through the secondary air ducts and entering the injection pipes is then sprayed toward the combustion zone;

[0012] The extension lines of the outlets of the multiple jet pipes are tangent to the same cylinder in the combustion zone, and the gases ejected from the multiple jet pipes can drive the materials in the combustion zone to rotate in the same circumferential direction.

[0013] Optionally, the outlet of the air jet pipe is inclined upward.

[0014] In a second aspect, the present invention provides a biomass boiler that uses a secondary air device;

[0015] Optionally, also include:

[0016] A hearth with multiple hoods evenly arranged on the hearth;

[0017] Gas blown from multiple hoods blows up the materials on the hearth and burns them in the combustion zone.

[0018] Optionally, the air outlet of the hood is tilted toward the hearth.

[0019] Optionally, a feeding device is also included, which is used to transport materials to the biomass boiler.

[0020] Optionally, the feeding device includes:

[0021] hopper;

[0022] Pneumatic feeding pipe, the discharge end of the hopper is connected to the pneumatic feeding pipe;

[0023] A feed pipe, one end of which is connected to the pneumatic feed pipe, and the other end of which passes through the hearth from top to bottom;

[0024] An air blowing device is connected to the end of the pneumatic feeding pipe away from the feeding pipe;

[0025] The blast device inputs gas into the wind feeding pipe, and the material falling from the hopper into the wind feeding pipe is transported to the feed pipe through the gas. The material in the feed pipe is sprayed into the biomass boiler under the action of the gas.

[0026] Optional feed connection includes:

[0027] Spraying section: The spraying section is fixed on the furnace bed, the axis of the spraying section is parallel to the vertical direction, and the material enters the boiler through the spraying section.

[0028] Optionally, also include:

[0029] The material guide pipe is connected to the discharge end of the hopper and the discharge end of the material guide pipe is connected to the pneumatic feeding pipe;

[0030] The conveying device is arranged in the material guide pipe, and the conveying device pushes the material in the material guide pipe to move toward the discharge end of the material guide pipe.

[0031] Optionally, also include:

[0032] The furnace wall and the furnace roof form a furnace, and the combustion area and the hearth are arranged in the furnace.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] The utility model makes the extension lines of the outlets of multiple jet pipes tangent to the same cylinder in the combustion zone, so that the gas ejected by the multiple jet pipes can drive the material in the combustion zone to rotate in the same circumferential direction. The centrifugal force generated by the rotation can extend the time the material stays in the combustion zone, making the combustion more complete. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention.

[0036] Figure 1 This is a schematic diagram of the internal structure of the utility model;

[0037] Figure 2 For this utility model Figure 1 sectional view of ;

[0038] Figure 3 A top view of the hearth of the utility model;

[0039] Figure 4 This is a structural diagram of the hopper of the utility model;

[0040] Figure 5 For this utility model Figure 4 Side view of;

[0041] Figure 6 This is a structural diagram of the feed pipe of the utility model;

[0042] Figure 7 This is a schematic diagram of the structure of the hood of the utility model;

[0043] Figure 8 This is the installation structure diagram of the hopper and biomass boiler of the utility model;

[0044] Figure 9 This is a gas path diagram of a pair of secondary air ducts in Example 1 of the present utility model;

[0045] Figure 10 This is an air circuit diagram of two pairs of secondary air ducts in Example 1 of the present utility model.

[0046] In the figure: 100, feeding device; 110, hopper; 120, pneumatic feeding pipe; 130, feeding pipe; 140, connecting pipe; 150, material guide pipe; 160, primary blanking pipe; 131, spraying section; 132, bending section; 133, connecting section; 141, secondary blanking pipe; 142, secondary feeding pipe; 151, conveying device; 200, air distribution device; 210, hearth; 220, wind hood; 221, air guide section; 222, connecting section; 223, gas storage section; 300, biomass boiler; 310, furnace wall; 320, furnace top; 400, secondary air device; 410, secondary air duct; 420, jet pipe. DETAILED DESCRIPTION

[0047] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0048] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0049] Example 1

[0050] Please refer to Figure 1-10 The present invention provides a secondary air device 400, which includes a pair of secondary air ducts 410. The pair of secondary air ducts 410 are symmetrically arranged on both sides of the combustion zone along the left-right direction.

[0051] Multiple air jets 420 are mounted on the secondary air duct 410. The gases ejected from these jets can move the biomass fuel, fly ash, and fly ash combustibles within the combustion zone, forming a circular trajectory. The secondary air device 400 stirs and mixes the gas and materials within the biomass boiler 300, creating a vortex within the flue gas and materials within the biomass boiler 300. This, firstly, prolongs the time the biomass fuel remains within the combustion zone; secondly, it increases the travel distance of suspended fly ash and fly ash combustibles within the furnace, further reducing their contents; and thirdly, it provides some air to the combustibles passing through the combustion zone, thereby improving boiler thermal efficiency, reducing initial exhaust smoke concentration, and facilitating energy conservation and environmental protection.

[0052] It should be noted that the extension lines of the outlets of the multiple air injection pipes 420 are tangent to the same cylinder in the combustion zone, and the cylinder here is not a solid body.

[0053] It should be noted that the reference Figure 9 When a pair of secondary air ducts 410 are used, the number of the air injection pipes 420 on each secondary air duct 410 is multiple.

[0054] It should be noted that if Figure 10 As shown, two or more pairs of secondary air ducts 410 may be arranged outside the combustion zone as required, wherein at least one air injection pipe 420 is provided on each secondary air duct 410 .

[0055] It should be noted that the combustion zone refers to the area where the biomass fuel burns in the furnace.

[0056] As a further solution, the outlet of the air jet 420 is tilted upward. The angle between the air jet 420 and the horizontal direction is 0 to 60 degrees. When the air jet 420 is tilted, the ejected gas acts on the biomass fuel, fly ash, and fly ash combustibles. This not only drives the biomass fuel, fly ash, and fly ash combustibles to rotate in the same circumferential direction, but also provides a vertical upward force on the biomass fuel, fly ash, and fly ash combustibles, increasing the time the biomass fuel, fly ash, and fly ash combustibles remain suspended and improving combustion efficiency.

[0057] It should be noted that the structure of the air jet pipe 420 can be further improved. For example, a nozzle can be provided at the outlet of the air jet pipe 420 , and the cross-sectional area of ​​the nozzle decreases along the air jet pipe 420 in a direction away from the secondary air duct 410 .

[0058] Example 2

[0059] refer to Figure 1-3 , providing an air distribution device 200 for use with Example 1, the air distribution device 200 includes a hearth 210 disposed in a biomass boiler 300, and a plurality of hoods 220 are evenly disposed on the hearth 210;

[0060] The gas ejected from the multiple hoods 220 forms multiple airflows from bottom to top. Under the action of the multiple airflows, the biomass fuel moves above the hearth 210 and burns in the combustion zone.

[0061] It should be noted that the hearth 210 uses an air distribution plate and is provided with at least one slag discharge port.

[0062] As a further solution, the hood 220 includes an air guide section 221, a connection section 222 and an air storage section 223 which are sequentially connected from bottom to top.

[0063] The air guide section 221 is connected to the air path, the horizontal cross-sectional dimension of the air storage section 223 is larger than the horizontal cross-sectional dimension of the air guide section 221, the connecting section 222 is an inclined surface or an arc surface, the air outlet of the hood 220 is set in the connecting section 222, and when the gas is ejected from the air outlet of the hood 220, it forms an angle with the horizontal plane.

[0064] Specifically, after the ejected gas strikes the upper surface of hearth 210, it refracts. The upwardly refracted gas forms an angle with the vertical direction. When it acts on the biomass fuel, it pushes the fuel upward vertically and moves the material horizontally away from hood 220. This allows for a more even horizontal dispersion of the biomass particles, fly ash, and combustibles in the fly ash. In this embodiment, hood 220 has eight air outlets, evenly distributed along the circumference of connecting section 222.

[0065] It should be noted that the gas in this solution is preferably air, and the gas can be further pressurized by a pressurizing device.

[0066] Example 3

[0067] refer to Figure 4 、 Figure 5 、 Figure 8 Based on Example 2, the feeding method of the biomass boiler 300 is further improved.

[0068] The feeding device 100 is used to transport biomass fuel to the biomass boiler 300. The feeding device 100 includes a hopper 110, a pneumatic feeding pipe 120, a feed pipe 130 and a blasting device, wherein the outlet of the feed pipe 130 is arranged in the boiler, and the feed pipe 130 passes through the furnace bed 210 from bottom to top; the pneumatic feeding pipe 120 is connected to the feed pipe 130, and the end of the pneumatic feeding pipe 120 away from the feed pipe 130 is connected to the blasting device. The hopper 110 is arranged outside the boiler, and the material discharged from the hopper 110 is input into the pneumatic feeding pipe 120.

[0069] Specifically, the biomass fuel in the hopper 110 falls into the wind feeding pipe 120, and the blowing device inputs gas into the wind feeding pipe 120. The gas drives the biomass fuel through the feed pipe 130 and enters the boiler to achieve feeding.

[0070] It should be noted that the blowing device can be a blower, an air compressor, etc.

[0071] It should be noted that the gas blown into the pneumatic feeding pipe 120 by the blowing device is preferably air.

[0072] It should be noted that in this embodiment, two sets of feeding devices 100 are preferably used, and the spraying sections 131 of the two sets of feeding devices 100 are symmetrically arranged along the front-to-back direction of the hearth 210. Obviously, the number of feeding devices 100 can be appropriately increased or decreased according to the size of the biomass boiler.

[0073] Example 4

[0074] refer to Figure 4 、 Figure 5 、 Figure 8 , the structure of the feed pipe 130 in Example 3 is described in detail.

[0075] The feed pipe 130 includes a spraying section 131, a curved section 132 and a connecting section 133 connected in sequence, wherein the connecting section 133 is connected to the wind feeding pipe 120, and the curved section 132 is arranged in an arc shape, which can guide the gas into the spraying section 131. The arc shape can guide the gas to turn and reduce the energy loss of the gas. The spraying section 131 is fixed on the furnace bed 210, and the opening of the spraying section 131 faces upward. After the biomass fuel is sprayed out through the spraying section 131, the gas diffuses after passing through the spraying section 131, and combined with the effect of gravity, the trajectory of the biomass fuel after spraying is parabolic, and it is dispersed to the surroundings along the opening of the spraying section 131 (the use of gas to drive the biomass fuel in conjunction with the spraying section 131 with an upward opening can disperse the agglomerated biomass fuel, so that the biomass fuel particles can fully contact with the air, reduce or avoid incomplete combustion, and improve combustion efficiency); further, after the feeding device 100 is equipped with multiple wind hoods 220, the biomass fuel can be more evenly distributed in the entire combustion area.

[0076] More preferably, the spraying section 131 is arranged in the vertical direction. In this way, it can be further ensured that the sprayed biomass fuel can be evenly dispersed around the spraying section 131.

[0077] It should be noted that the above solution does not limit the directions of the wind feeding pipe 120 and the connecting section 133. Preferably, in this solution, the wind feeding pipe 120 and the connecting section 133 are arranged in the horizontal direction.

[0078] Example 5

[0079] refer to Figure 4 、 Figure 5 、 Figure 8 Based on Example 3, the connection method between the hopper 110 and the wind feeding pipe 120 is further improved.

[0080] A guide pipe 150 is also provided, and the discharge end of the hopper 110 is connected to the guide pipe 150, and the discharge end of the guide pipe 150 is connected to the wind feeding pipe 120; a conveying device 151 is provided in the guide pipe 150, and the biomass fuel transported to the guide pipe 150 by the hopper 110 is pushed by the conveying device 151 and moves toward the discharge end of the guide pipe 150.

[0081] By providing the guide pipe 150 and the conveying device 151 , blockage during the biomass fuel conveying process can be prevented, thereby achieving continuous feeding.

[0082] As a further solution, the conveying device 151 can be any one of a screw conveying device, a conveyor belt, and a vibrating machine.

[0083] More preferably, the spiral conveying device includes a rotating shaft and blades spirally wound around the outer wall of the rotating shaft. The rotating shaft is driven to rotate by a motor, thereby pushing the biomass fuel toward the discharge end of the guide pipe 150 through the blades.

[0084] As a further solution, a connecting pipe 140 is further provided. The upper end of the connecting pipe 140 is communicated with the discharge end of the material guide pipe 150 , and the lower end of the connecting pipe 140 is communicated with the wind feeding pipe 120 .

[0085] Further preferably, the connecting pipe 140 includes a secondary drop pipe 141 and a secondary feed pipe 142 which are interconnected from top to bottom.

[0086] More preferably, the cross-sectional area of ​​the secondary drop pipe 141 increases from top to bottom. This approach can increase the drop speed and prevent blockage. The cross-sectional area of ​​the secondary feed pipe 142 decreases from top to bottom, allowing the lower end of the secondary feed pipe 142 to adapt to the relatively small pneumatic feed pipe 120. The cross-sections of the secondary drop pipe 141 and the secondary feed pipe 142 are both rectangular, and the longitudinal cross-sections of the secondary drop pipe 141 and the secondary feed pipe 142 along the front-to-back direction are both triangular, and the angle between the two inclined surfaces of the secondary drop pipe 141 is smaller than the angle between the two inclined surfaces of the secondary feed pipe 142.

[0087] The secondary feeding pipe 142 is tilted, and the wind feeding pipe 120 is arranged in the left and right directions. Figure 8Biomass fuel enters biomass boiler 300 from right to left, with the upper end of secondary feed pipe 142 located on the right and the lower end on the left. This design not only provides a force for the biomass fuel to move leftward, reducing the force required for the gas to propel the biomass fuel, but also prevents gas from entering guide pipe 150 along connecting pipe 140.

[0088] As a further solution, a primary discharge pipe 160 is provided. The upper end of the primary discharge pipe 160 is connected to the discharge end of the hopper 110, and the lower end of the primary discharge pipe 160 is connected to the feed end of the guide tube 150. By providing the primary discharge pipe 160, the hopper 110 and the guide tube 150 can be connected, so that the material in the hopper 110 can be transported to the guide tube 150.

[0089] Further preferably, the cross-section of the single-time blanking pipe 160 is rectangular, the cross-sectional area of ​​the single-time blanking pipe 160 decreases from top to bottom, and the longitudinal section of the single-time blanking pipe 160 along the front-to-back direction is triangular. In this way, the single-time blanking pipe 160 can be matched with the smaller material guide tube 150.

[0090] Example 6

[0091] refer to Figure 1 、 Figure 2 The present invention also provides a biomass boiler 300 , which adopts the aforementioned secondary air device 400 , feeding device 100 and air distribution device 200 .

[0092] Furnace walls 310 are arranged around the air distribution device 200, and a furnace roof 320 is located above the air distribution device 200, forming a furnace. Both the furnace walls 310 and the furnace roof 320 are made of refractory clay. The secondary air duct 410 and the air injection pipe 420 are embedded in the furnace walls 310. A furnace constructed in this manner can improve thermal efficiency, save energy, improve thermal performance, extend service life, reduce pollution emissions, and optimize combustion.

[0093] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A secondary air device, comprising at least one pair of secondary air ducts (410), wherein the pair of secondary air ducts (410) are symmetrically arranged on both sides of a combustion zone, and the secondary air ducts (410) are provided with at least one injection pipe (420) at intervals along the length direction thereof, and gas enters the injection pipe (420) through the secondary air ducts (410) and is then sprayed toward the combustion zone; characterized in that: The extension lines of the outlets of the multiple jet pipes (420) are tangent to the same cylinder in the combustion zone, and the gases ejected from the multiple jet pipes (420) can drive the materials in the combustion zone to rotate in the same circumferential direction.

2. The secondary air device according to claim 1, characterized in that: The outlet of the air injection pipe (420) is inclined upward.

3. A biomass boiler, characterized in that: A secondary air device according to any one of claims 1 or 2 is used.

4. The biomass boiler according to claim 3, characterized in that: It also includes an air distribution device, which includes: A hearth (210), with a plurality of hoods (220) evenly arranged on the hearth (210); Gas blown out from the multiple hoods (220) blows up the materials on the hearth (210) and burns them in the combustion zone.

5. The biomass boiler according to claim 4, characterized in that: The air outlet of the hood (220) faces the hearth (210) and is tilted.

6. The biomass boiler according to claim 4, characterized in that: It also includes a feeding device, which is used to transport materials to the biomass boiler.

7. The biomass boiler according to claim 6, characterized in that: The feeding device includes: Hopper (110); A pneumatic feeding pipe (120), the discharge end of the hopper (110) is connected to the pneumatic feeding pipe (120); A feed pipe (130), one end of which is connected to the pneumatic feed pipe (120), and the other end of which passes through the furnace bed (210) from top to bottom; An air blowing device connected to an end of the pneumatic feeding pipe (120) away from the feeding pipe (130); The blast device inputs gas into the wind feeding pipe (120), and the gas transports the material into the feeding pipe (130). The material in the feeding pipe (130) is sprayed into the biomass boiler (300) under the action of the gas.

8. The biomass boiler according to claim 7, characterized in that: The feed pipe (130) includes: The spraying section (131) is fixed on the furnace bed (210), the axis of the spraying section (131) is parallel to the vertical direction, and the material enters the boiler through the spraying section (131).

9. The biomass boiler according to claim 7, characterized in that: Also includes: A material guide pipe (150), the material discharge end of the hopper (110) is in communication with the material guide pipe (150), and the material discharge end of the material guide pipe (150) is in communication with the pneumatic feeding pipe (120); The conveying device (151) pushes the material in the material guide pipe (150) to move toward the discharge end of the material guide pipe (150).

10. The biomass boiler according to claim 4, characterized in that: Also includes: The furnace wall (310) and the furnace top (320) form a furnace, and the furnace wall (310) and the furnace top (320) form a furnace. The combustion zone and the hearth (210) are both located in the furnace.

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