A biomass low-nitrogen combustion system

Abstract

The application provides a biomass low-nitrogen combustion system, and relates to the field of biomass combustion equipment; the system comprises a storage unit, a first conveying unit, a premixing unit, a second conveying unit and a combustion chamber; the storage unit is used for storing powdered biomass; the input end of the first conveying unit is connected with the output end of the storage unit; the premixing unit comprises a tank body, the tank body is provided with an input port connected with the output unit of the first conveying unit, and the tank body is provided with an agitating part capable of rotating under the drive of a power unit; the feeding port of the second conveying unit is connected with the output port of the tank body, and the discharging port of the second conveying unit is connected with the feeding end of the combustion chamber; and the biomass low-nitrogen combustion system can make the biomass fully burn, so that the content of nitrogen oxides in the gas after the biomass burns is reduced.

Description

Technical Field

[0001] This invention relates to the field of biomass combustion equipment technology, specifically to a low-NOx biomass combustion system. Background Technology

[0002] A biomass burner is a device that efficiently burns biomass fuel and converts it into heat energy. It is widely used in heating, hot water supply and industrial heat sources.

[0003] Existing biomass burners require the biomass to be made into pellets. Biomass pellets have a large surface area but a small contact area with air, resulting in high nitrogen oxide (NOx) emissions. Furthermore, to ensure complete combustion, an excess of air is required, leading to high oxygen content in the exhaust gas. Moreover, biomass pellet fuel generally has a high water content, and its ash content, along with impurities, easily forms coke. If the feed rate of the biomass pellet burner is too fast, the existing biomass pellets in the furnace may not be fully combusted before new pellets cover the furnace. Locally, the temperature may become excessively high, exceeding the ash melting point. At high temperatures, most ash melts into a liquid or softened state. If the ash remains softened and comes into contact with heated surfaces, it will adhere to the heated surfaces due to cooling, forming coke. Summary of the Invention

[0004] To address this issue, the present invention proposes a low-NOx combustion system for biomass, which can at least partially solve the technical problem of high NOx emission concentrations in existing biomass burners.

[0005] The technical solution of the present invention is as follows: A low-NOx biomass combustion system includes a storage unit, a first conveying unit, a premixing unit, a second conveying unit, and a combustion chamber. The storage unit stores powdered biomass, and the input end of the first conveying unit is connected to the output end of the storage unit. The premixing unit includes a tank with an input port connected to the output end of the first conveying unit, and an agitator that can be rotated by a power unit inside the tank. The inlet of the second conveying unit is connected to the output port of the tank, and the outlet of the second conveying unit is connected to the inlet of the combustion chamber.

[0006] Furthermore, the first conveying unit is a belt conveyor or a screw conveyor.

[0007] Furthermore, the interior of the tank is provided with a tray located below the agitator and the unblocking rod. The tray is connected to the inner wall of the tank by a flexible material around its perimeter. A plurality of elastic elements are provided between the bottom surface of the tray and the inner wall of the tank. A transmission part is provided between the tray and the agitator. The tray has a first stroke that is driven downward by the transmission part and a second stroke that is pushed upward by the elastic elements.

[0008] Furthermore, the transmission unit includes a drain rod with one end fixed to the tray and the other end extending into the inlet. The drain rod can clear the inlet as the tray reciprocates.

[0009] Furthermore, the power unit is a motor fixed to the outside of the tank, and the agitator includes a rotating shaft that can be driven to rotate by the motor, and several sets of fan blades fixed on the rotating shaft. Each of the fan blades can blow air upward as the rotating shaft rotates.

[0010] Furthermore, a process rod is fixed on the tray; and two guide holes are fixed on the inner wall of the tank, the unblocking rod can slide within one of the two guide holes, and the process rod can slide within the other of the two guide holes.

[0011] Furthermore, the transmission unit also includes a transmission shaft rotatably disposed in the tank body. The transmission shaft and the rotating shaft are driven by gears so that the transmission shaft can rotate with the rotating shaft. A turntable is fixed on the bottom end of the transmission shaft, and a wedge block is fixed on the turntable. As the transmission shaft rotates, the wedge block can periodically press down on the unblocking rod.

[0012] Furthermore, a process tray is fixed on the tray, the process tray protrudes from the upper end surface of the tray, and a plurality of ventilation holes are fixed on the outer peripheral surface of the process tray. Each ventilation hole is circumferentially spaced around the process tray, and each ventilation hole is connected to an external aerodynamic device.

[0013] The working principle and beneficial effects of this invention are as follows: The biomass low-NOx combustion system provided by this invention stores powdered biomass in a storage unit, premixes the biomass and air in the tank, and then transports it into the combustion chamber for combustion. Since the powdered biomass can fully contact the air, it can also burn more completely, thereby reducing the emission concentration of nitrogen oxides. Attached Figure Description

[0014] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0015] Figure 1 This is a schematic diagram of the overall structure of the biomass low-NOx combustion system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the premixing unit provided in an embodiment of the present invention; Figure 3 for Figure 2 A magnified view of a section at point A in the middle; Figure 4 for Figure 2 A local magnification at point B in the middle; In the diagram: 100, storage unit; 200, first conveying unit; 300, premixing unit; 310, tank; 320, power unit; 330, stirring part; 331, rotating shaft; 332, blade; 340, tray; 341, flexible material; 342, elastic element; 350, unblocking rod; 360, process rod; 301, guide hole; 302, inlet; 400, second conveying unit; 500, combustion chamber; 600, push plate; 700, drive shaft; 710, turntable; 720, wedge block; 800, process plate; 810, vent. Detailed Implementation

[0016] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0017] This invention provides a low-NOx biomass combustion system, comprising a storage unit 100, a first conveying unit 200, a premixing unit 300, a second conveying unit 400, and a combustion chamber 500. The storage unit 100 stores powdered biomass, and the input end of the first conveying unit 200 is connected to the output end of the storage unit 100. The premixing unit 300 includes a tank 310, which has an input port 302 connected to the output unit of the first conveying unit 200, and an agitator 330 that can be rotated by a power unit 320 inside the tank 310. The feed inlet of the second conveying unit 400 is connected to the output port of the tank 310, and the discharge port of the second conveying unit 400 is connected to the feed end of the combustion chamber 500.

[0018] Based on the above overall structure, in use, the biomass low-NOx combustion system of this embodiment allows the pre-powdered biomass to be stored in the storage unit 100. When the combustion chamber 500 is operating, the first conveying unit 200 transports the powdered biomass to the premixing unit 300. After the biomass powder is fully mixed with air in the premixing unit 300, it is then transported to the combustion chamber 500 by the second conveying unit 400 for combustion. Compared with the prior art, the biomass low-NOx combustion system of this application, because the biomass powder and air are fully mixed in the premixing unit 300, allows the powdered biomass to burn fully in the combustion chamber 500 after being transported there, thereby reducing the emission concentration of nitrogen oxides.

[0019] In terms of specific structure, the storage unit 100 in this embodiment can be a storage tower, and its specific structure can be referred to existing products, which will not be described in detail here. The first conveying unit 200 in this embodiment is a screw conveyor. In some embodiments, the first conveying unit 200 can also be a belt conveyor. It should be noted that both screw conveyors and belt conveyors can be referred to existing products, and will not be described in detail here either.

[0020] refer to Figure 1 and Figure 2 As shown, the tank 310 in this embodiment is cylindrical, with an inlet 302 on one side of its top. The inner hole of the inlet pipe is connected to the inner cavity of the tank 310, and the powdered biomass conveyed by the first conveying unit 200 can enter the inner cavity of the tank 310 through the inlet 302.

[0021] refer to Figure 2 As shown, the power unit 320 in this embodiment is a motor fixed to the outside of the tank 310, and the stirring part 330 in this embodiment includes a rotating shaft 331 that can be driven to rotate by the motor, and several sets of fan blades fixedly mounted on the rotating shaft 331. Each set of fan blades is spaced apart along the axial direction of the rotating shaft 331, and each set of fan blades can blow air upward as the rotating shaft 331 rotates. The structure of the fan blades can be referred to the prior art, and will not be described in detail here.

[0022] By setting up the power unit 320 and the agitator 330, the blowers blow air upwards. When the powdered biomass falls from the inlet 302, it can be blown upwards by the blowers, so that the powdered biomass is diffused throughout the tank 310. This allows the powdered biomass to be fully mixed with air in the tank 310, which is beneficial for the complete combustion of the powdered biomass after it is transported to the combustion chamber 500.

[0023] refer to Figure 2 As shown, in this embodiment, a tray 340 is also provided inside the tank 310, located below the stirring part 330. The tray 340 is connected to the inner wall of the tank 310 by a flexible material 341 around its perimeter. A plurality of elastic members 342 are provided between the bottom surface of the tray 340 and the inner wall surface of the tank 310. A transmission part is provided between the tray 340 and the stirring part 330. Through the transmission part, the tray 340 has a first stroke driven by the stirring part 330 to move downward, and a second stroke pushed by the elastic members 342 to bounce upward.

[0024] In simple terms, in this embodiment, a tray 340 is provided at the bottom of the tank 310. The tray 340 is connected to the inner wall of the tank 310 by a flexible material 341, such as cloth or plastic sheeting. That is, the tray 340 constitutes the bottom of the tank 310 for supporting materials. In this embodiment, by setting the tray 340 and having it periodically bounce up, the biomass falling on the tray 340 can be bounced back into the tank 310. Then, the blades 332 blow the biomass upward, allowing the powdery biomass falling on the tray 340 to participate in the mixing again, preventing it from accumulating at the bottom of the tank 310.

[0025] If the aforementioned pop-up tray 340 is not installed, even though the fan blades that can blow air upwards are installed, some powdery biomass will still deposit at the bottom of the tank 310. As the powdery biomass deposits at the bottom of the tank 310, the tank 310 will gradually lose its premixing function.

[0026] refer to Figure 2 As shown, the transmission unit in this embodiment includes a drain rod 350 with one end fixedly mounted on the tray 340. The other end of the drain rod 350 extends into the inlet 302, allowing the drain rod 350 to clear the inlet 302 as the tray 340 reciprocates. In this embodiment, a process rod 360 is also fixedly mounted on the tray 340, and two guide holes 301 are fixedly mounted on the inner wall of the tank 310. The drain rod 350 can slide within one of the two guide holes 301, and the process rod 360 can slide within the other guide hole 301. By providing two guide holes 301 and allowing the drain rod 350 and process rod 360 to slide within the two guide holes 301 respectively, guidance can be provided for the sliding of the drain rod 350 and the sliding of the tray 340.

[0027] refer to Figure 2 As shown, the transmission unit in this embodiment also includes a transmission shaft 700 rotatably disposed in the tank body 310. The transmission shaft 700 and the rotating shaft 331 are driven by gears so that the transmission shaft 700 can rotate with the rotating shaft 331 and can decelerate relative to the rotational speed of the rotating shaft 331. The specific gear reduction mechanism can be referred to the prior art, and will not be described in detail here.

[0028] In this embodiment, reference Figures 2 to 3As shown, a turntable 710 is fixed at the bottom end of the drive shaft 700, and two wedge blocks 720 are fixed on the bottom surface of the turntable 710. A support plate 600 is connected between the unblocking rod 350 and the process rod 360. As the drive shaft 700 rotates, when the wedge block 720 contacts the support plate 600, the wedge block 720 can press down on the support plate 600, i.e., the unblocking rod 350. When the wedge block 720 crosses the support plate 600, the tray 340 can quickly bounce upward under the push of the elastic element 342, thereby realizing the periodic bounce of the tray 340. On the one hand, it drives the unblocking rod 350 to unblock the inlet 302, and on the other hand, it bounces the powdery biomass falling on the tray 340 into the air to participate in the mixing.

[0029] refer to Figure 2 and Figure 4 As shown, in this embodiment, a process tray 800 is also fixed on the tray 340. The process tray 800 protrudes from the upper surface of the tray 340, and a plurality of vent holes 810 are fixed on the outer periphery of the process tray 800. Each vent hole 810 is arranged circumferentially around the process tray 800 at intervals. Along the direction from the center of the process tray 800 to the outside of the process tray 800, each vent hole 810 is inclined upward. Each vent hole 810 is connected to an external aerodynamic device via a pipeline. In this embodiment, by setting the above-mentioned process tray 800, the external aerodynamic device can introduce air flowing obliquely upward into the tank 310 through each vent hole 810. The powdery biomass that bounces with the tray 340 can be pushed upward by the air discharged from each vent hole 810, thereby being able to participate in the premixing in the tank 310 better.

[0030] The second conveying unit 400 and combustion chamber 500 in this embodiment can also refer to the prior art, and their structure and working principle will not be described in detail in this embodiment. The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A biomass low-NOx combustion system, characterized in that: The system includes a storage unit (100), a first conveying unit (200), a premixing unit (300), a second conveying unit (400), and a combustion chamber (500). The storage unit (100) is used to store powdered biomass. The input end of the first conveying unit (200) is connected to the output end of the storage unit (100). The premixing unit (300) includes a tank (310). The tank (310) is provided with an input port (302) connected to the output unit of the first conveying unit (200). The tank (310) is provided with an agitator (330) that can be driven to rotate by a power unit (320). The feed inlet of the second conveying unit (400) is connected to the output port on the tank (310), and the discharge port of the second conveying unit (400) is connected to the feed end of the combustion chamber (500).

2. The biomass low-NOx combustion system according to claim 1, characterized in that, The first conveying unit (200) is a belt conveyor or a screw conveyor.

3. The biomass low-NOx combustion system according to claim 1, characterized in that, The tank (310) has a tray (340) located below the stirring part (330) inside. The tray (340) is connected to the inner wall of the tank (310) by a flexible material (341) around its perimeter. A plurality of elastic elements (342) are provided between the bottom surface of the tray (340) and the inner wall of the tank (310). A transmission part is provided between the tray (340) and the stirring part (330). Through the transmission part, the tray (340) has a first stroke driven by the stirring part (330) to move downward, and a second stroke pushed by the elastic elements (342) to bounce upward.

4. The biomass low-NOx combustion system according to claim 3, characterized in that, The transmission unit includes a drain rod (350) with one end fixed to the tray (340) and the other end of the drain rod (350) extending into the inlet (302). The drain rod (350) can clear the inlet (302) as the tray (340) moves back and forth.

5. The biomass low-NOx combustion system according to claim 4, characterized in that, The power unit (320) is a motor fixed to the outside of the tank (310). The stirring part (330) includes a rotating shaft (331) that can be driven to rotate by the motor, and several sets of fan blades fixed on the rotating shaft (331). Each set of fan blades can blow air upward as the rotating shaft (331) rotates.

6. The biomass low-NOx combustion system according to claim 5, characterized in that, A process rod (360) is fixed on the tray (340); and two guide holes (301) are fixed on the inner wall of the tank (310). The unblocking rod (350) can slide within one of the two guide holes (301), and the process rod (360) can slide within the other of the two guide holes (301).

7. The biomass low-NOx combustion system according to claim 6, characterized in that, The transmission unit also includes a transmission shaft (700) rotatably disposed in the tank (310). The transmission shaft (700) and the rotating shaft (331) are driven by gears so that the transmission shaft (700) can rotate with the rotating shaft (331). A turntable (710) is fixedly disposed on the bottom end of the transmission shaft (700). A wedge block (720) is fixedly disposed on the turntable (710). As the transmission shaft (700) rotates, the wedge block (720) can periodically press down the unblocking rod (350).

8. The biomass low-NOx combustion system according to claim 3, characterized in that, A process disk (800) is fixed on the tray (340). The process disk (800) protrudes from the upper end face of the tray (340). A plurality of ventilation holes (810) are fixed on the outer peripheral surface of the process disk (800). Each ventilation hole (810) is arranged circumferentially around the process disk (800). Along the direction from the center of the process disk (800) to the outside of the process disk (800), each ventilation hole (810) is inclined upward. Each ventilation hole (810) is connected to an external aerodynamic device.

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