Feeding system of updraft fixed bed biomass gasifier and operation method of feeding system

Abstract

The invention relates to an updraft type fixed bed biomass gasification furnace feeding system and an operation method thereof.The feeding system comprises a gasification furnace body (1), a conical stock bin (2), a biomass gas guiding-out device, a feeding conveying device and an ash tray water seal device (3), and the conical stock bin (2) is arranged in the middle of the top end of the gasification furnace body (1); the biomass gas leading-out device comprises at least two biomass gas outlets (4) which are symmetrically distributed on the two sides of the conical stock bin (2), the conical stock bin (2) is connected with the feeding and conveying device, the ash tray water seal device (3) is arranged at the bottom end of the gasifier body (1), and a spraying system (8) is arranged above a chain scraper conveyor (5) of the feeding device. Compared with the prior art, the updraft type fixed bed biomass gasification furnace has the advantages that through the material sealing design of the feeding hole, the water sealing design of the ash basin at the bottom of the gasification furnace body and the arrangement of the spraying system, the updraft type fixed bed biomass gasification furnace has better sealing performance and safety.

Description

Technical Field

[0001] The present invention relates to the technical field of gasifier structures, and in particular to an updraft fixed-bed biomass gasifier feeding system and an operation method thereof. Background Art

[0002] An updraft fixed-bed biomass gasifier is a device that converts solid biomass into clean combustible gas, and its height is usually about ten-odd meters. Biomass fuel needs to be crushed to an appropriate particle size and then fed into the material inlet at the top of the gasifier through a conveyor. During the conveying process, dust is easily generated, which affects the plant environment.

[0003] The gasifier is divided into a drying layer, a pyrolysis layer, a reduction layer, and an oxidation layer from top to bottom (as Figure 1 shown). The fuel is added from the upper part of the furnace and slowly moves down, supported by the grate. The gasifying agent enters from the lower part, and the gas is discharged from the upper part. The distribution of each reaction zone is crucial for the gasification effect. The gasification reaction needs to be carried out in an oxygen-deficient environment, and the generated gas is flammable and explosive, so the gasifier has high requirements for airtightness. However, the gasifier cannot be designed as a fully enclosed structure because continuous feeding is required. Especially for the feeding port of the upper silo, special attention should be paid to preventing gas leakage and air entry to avoid affecting the gasification process and gas quality.

[0004] Biomass gasification technology, as an energy conversion method that efficiently converts solid biomass into clean combustible gas, its core lies in converting biomass raw materials (such as agricultural waste, forestry residues, etc.) into syngas rich in combustible components such as CO, H2, CH4, etc. under oxygen-deficient conditions through a thermochemical process. A typical updraft fixed-bed gasifier adopts a four-stage reaction structure of "drying - pyrolysis - reduction - oxidation", the raw material vertically drops from the top of the furnace, and the gasification medium (air / oxygen / water vapor) is blown in from the bottom, and the gas is led out from the top. This process is extremely sensitive to the control of reaction conditions.

[0005] The existing updraft fixed-bed biomass gasifiers mainly have the following problems: The gasification reaction needs to be carried out in a strictly oxygen-deficient environment, but the raw materials need to be continuously added and the gas needs to be continuously exported. Traditional sealing structures (such as single gate valves) are difficult to balance the dual requirements of dynamic feeding and gas barrier, and are prone to gas leakage or air backflow, resulting in explosion risks or a decrease in reaction efficiency; The height of the fixed-bed gasifier is generally about ten-odd meters, and a large amount of dust is easily generated during the raw material transportation, screening, and falling process of the existing feeding device, seriously polluting the working environment and threatening the health of workers; The moisture content of the raw materials needs to be controlled in the range of 15% - 25%. Too high will lead to a decrease in the gasification rate, and too low will intensify the severity of the reaction, causing local overheating and even furnace body damage.

[0006] Therefore, there are still technical bottlenecks in the prior art in aspects such as dynamic seal coordination and material humidity adjustment. There is an urgent need for an upper-suction fixed-bed biomass gasification furnace feeding system that integrates sealing and safety. Summary of the Invention

[0007] The purpose of the present invention is to provide an upper-suction fixed-bed biomass gasification furnace feeding system and its operation method, so that the upper-suction fixed-bed biomass gasification furnace has better sealing and safety.

[0008] The purpose of the present invention can be achieved through the following technical solutions:

[0009] The present invention provides an upper-suction fixed-bed biomass gasification furnace feeding system, which is characterized by including a gasification furnace body, a conical silo, a biomass gas export device, a feeding and conveying device, and an ash pan water seal device. The conical silo is arranged in the middle of the top of the gasification furnace body. The biomass gas export device includes at least two biomass gas outlets symmetrically distributed on both sides of the conical silo. The conical silo is connected to the feeding and conveying device, and the ash pan water seal device is arranged at the bottom end of the gasification furnace body;

[0010] The feeding and conveying device includes a chain conveyor, a buffer silo, and a feeding auger. The chain conveyor transports the material to the buffer silo and then transports it to the conical silo through the feeding auger. A spraying system is arranged above the chain conveyor.

[0011] Preferably, the chain conveyor includes an inclined lifting section, the inclination angle α of the inclined lifting section is 30 - 45°, the material input end of the chain conveyor is connected to a feeding hopper, and the feeding hopper is buried underground.

[0012] More preferably, the inclination angle α of the inclined lifting section is 38°.

[0013] Preferably, the chain conveyor is provided with a plurality of humidity sensors for detecting the humidity of the material.

[0014] In the present invention, the lower feeding hopper is buried underground. One is to avoid dust, and the other is that it will be simpler and faster to use a forklift for feeding, which is convenient for operation and saves time cost.

[0015] The present invention uses a chain conveyor for material transportation. The chain conveyor is particularly suitable for transporting materials with small volume and regular shape. Its conveying surface is flat and smooth, with small friction, which can ensure the stability of the material during transportation; the chain conveyor runs stably, the conveying speed is relatively slow and stable, and it is not easy to get stuck or malfunction, which can ensure long-term reliable operation.

[0016] In the present invention, the conveying inclination angle of the chain plate conveyor is relatively large (30 - 45°), and it can be flexibly arranged according to actual requirements, saving floor area; the chain plate conveyor has a simple structure, is convenient for maintenance, and is easy to operate, suitable for various industrial environments and capable of meeting different production requirements.

[0017] Further preferably, the spraying system includes a support plate and a plurality of spraying units evenly distributed on the support plate. The support plate is horizontally arranged above the chain plate conveyor. The spraying unit includes an atomizing nozzle and a PLC controller. The PLC controller can receive the humidity signal detected by the humidity sensor and regulate the spraying intensity of the spraying unit.

[0018] Further preferably, when the detected value of the humidity sensor < 15%, the spraying unit increases the spraying intensity until the material humidity reaches between 15% - 25%.

[0019] Further preferably, the spraying direction of the atomizing nozzle forms an angle of 45 - 90° with the material conveying direction of the chain plate conveyor.

[0020] The gasification reaction has certain requirements for the particle size of the biomass raw material. Therefore, the materials are broken through the previous process and then sent into the furnace for combustion to produce gas. During the conveying process, dust is inevitably generated, which affects the plant environment. Therefore, in the present invention, a spraying system is installed above the chain plate conveyor. On the one hand, it can reduce the dust generated during the conveying process of the materials; on the other hand, it can change the dry - wet degree of the materials. Especially for the debris residues in building floors and wooden box packages, if the water content of the materials is less than 15%, the gasification reaction will be too intense, which may lead to the situation of over - temperature of the furnace body.

[0021] Preferably, the ash pan water seal device includes a rotary ash pan unit and an ash pan. The rotary ash pan unit is arranged inside the bottom end of the gasification furnace body, and the ash pan is arranged on the outer periphery of the bottom end of the gasification furnace body. There is a gap between the ash pan and the gasification furnace body, and the gap serves as a slag chute. The slag chute is communicated with the ash pan, and the ash pan contains water for sealing.

[0022] In the present invention, the biomass residues after the combustion of the biomass raw materials are slowly discharged from the slag chute through the rotation of the rotary ash pan unit and float on the water surface of the ash pan.

[0023] Preferably, the buffer bin is respectively connected to the material output end of the chain plate conveyor and the feed inlet of the feed auger. The discharge port of the feed auger is connected to the top end of the conical bin. An inlet gate valve for controlling the material feed quantity is arranged between the discharge port of the feed auger and the conical bin.

[0024] Preferably, the feeding auger includes a trough, a rotating shaft axially penetrating the trough, and a spiral blade spirally wound around the rotating shaft. The feeding port of the feeding auger is opened at one end of the trough, and the discharging port is opened at the other end of the trough. One end of the rotating shaft close to the feeding port of the feeding auger is connected with a driving device that provides power for the rotation of the rotating shaft, and the driving device includes a motor and a speed reducer.

[0025] In the present invention, the feeding auger is mainly composed of a spiral blade, a rotating shaft, a trough, and a driving device. The spiral blade is the core component for conveying materials, and it is wound around the rotating shaft in a spiral shape. The rotating shaft serves as the support for the spiral blade, not only providing a stable rotation center for the blade, but also having sufficient strength and rigidity itself to withstand the gravity of the materials and the friction and pressure generated during the conveying process. The driving device usually consists of a motor and a speed reducer, which provides power for the rotation of the rotating shaft and can flexibly adjust the rotation speed according to actual production requirements. After the materials enter the trough from the feeding port, the spiral blade exerts two forces on the materials: one is the circumferential force along the tangent direction of the spiral line, which causes the materials to move in a circular motion around the rotating shaft; the other is the thrust along the axial direction of the trough, which pushes the materials towards the discharging port. Due to the friction between the materials and the trough wall, the circular motion of the materials is restricted, so the materials mainly move in the axial direction, thus realizing efficient conveying from the feeding end to the discharging end. Since the rotation speed of the feeding auger motor is adjustable, the feeding speed can be accurately controlled, and then the height of the material layer in the gasifier can be effectively regulated.

[0026] Preferably, the bottom end of the conical silo extends into the inner cavity of the gasifier body. The conical silo has a structure that is narrow at the top and wide at the bottom, and the cross-sectional area at the top of the conical silo is smaller than that at the bottom.

[0027] In the present invention, the design of the conical silo is considered for the following two points: 1. In terms of sealing performance, since the upper part of the gasifier is in a positive pressure environment, by utilizing the self-weight of the biomass fuel, a certain resistance can be formed at the feeding port, effectively preventing the gas in the furnace from leaking through the feeding port, ensuring that the gas in the furnace only discharges through the biomass gas outlets on both sides of the silo, and achieving a good sealing effect (material seal); 2. In terms of ash content control and combustion efficiency, when the biomass fuel enters the furnace chamber of the gasifier body, since its falling process is not a free fall, but a smooth fall along the structure of the conical silo, no dusting phenomenon will occur, thus significantly reducing the ash content in the biomass gas. At the same time, the narrow-top and wide-bottom structure of the conical silo enables the materials to be more evenly dispersed and spread during the falling process, further improving the uniformity and sufficiency of combustion.

[0028] Preferably, two level gauges are symmetrically distributed on both sides of the upper end wall of the conical silo for real-time monitoring of the height of the material layer.

[0029] Further preferably, the level gauge includes a mechanical rotary level gauge, which is vertically arranged on the wall of the conical bin, and the included angle β between it and the wall of the conical bin is 90°.

[0030] Preferably, a gas filtration assembly is provided at each biomass gas outlet.

[0031] The present invention also provides an operation method for the feeding system of the up-draft fixed-bed biomass gasifier described above. The material is transported into the conical bin through the feeding and conveying device, and then enters the gasifier body and burns and gasifies. The gas generated after the material burns and gasifies is exported through the biomass gas outlet, and the residue generated after the material burns and gasifies is discharged through the ash pan water seal device. During this process, the spraying system can adjust the humidity of the material.

[0032] Preferably, the material includes biomass raw materials.

[0033] In the feeding system of the up-draft fixed-bed biomass gasifier provided by the present invention, on the one hand, the entire cavity inside the gasifier is in a sealed state. The feeding port forms a sealed space by material sealing, and the lower ash pan is isolated from air by water sealing. The positive pressure in the upper part of the furnace can just make the biomass gas enter the burner in the next link and burn out along the biomass gas outlet. Such a structure is simple, but the operation is stable and convenient, and it is convenient to operate. While ensuring the good sealing of the gasifier, it can prevent the escape of biomass gas and cause safety accidents. The entry and exit of the material can also be appropriately adjusted through the feeding gate valve, which can flexibly control the feeding quantity while ensuring the operation safety.

[0034] On the other hand, the feeding device of the up-draft fixed-bed biomass gasifier feeding system provided by the present invention transports the material to the height of the gasifier feeding port through a chain conveyor, and then sends the material into the gasifier for high-temperature pyrolysis by a feeding auger (screw conveyor). During the feeding process, the spraying system can adjust the dryness and humidity of the material, increase its water content, and make the gasification process proceed well; at the same time, it can also reduce the floating dust during the feeding process and improve the air quality in the factory area. The chain conveyor adopted in the feeding device of the present invention uses chain drive, and the matching precision between the chain and the gear is high, the transmission efficiency is high, the operation is stable and reliable, which ensures the continuous transportation of the material and reduces the occurrence of blockage and faults.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] (1) The present invention provides a feeding system for an up-draft fixed-bed biomass gasifier. Through the material sealing design of the feeding port, the water sealing design of the ash pan at the bottom of the gasifier body, and the setting of the spraying system, the up-draft fixed-bed biomass gasifier has good sealing and safety.

[0037] (2) The present invention adopts the form of material seal at the feed inlet and water seal at the ash pan at the bottom of the gasifier body to make the entire interior of the gasifier a closed space. The positive pressure in the upper part of the gasifier furnace can just make the biomass gas flow out from the biomass gas outlets on both sides of the conical bin and enter the burner to burn out completely, which can keep the gasifier running at a high gasification efficiency for a long time. At the same time, it can ensure the operation safety of the gasifier when producing gas, improve the gas production rate and guarantee the gasification quality.

[0038] (3) After the present invention conveys the material to the height of the feed inlet of the gasifier through the chain conveyor, the feed auger (screw conveyor) then sends the material into the gasifier for high-temperature pyrolysis. During the feeding process, the spraying system can adjust the dryness and humidity of the material, increase its water content, reduce the dust during the transportation of the material, make the gasification process proceed well, and ensure its safety.

[0039] (4) In the present invention, since the rotation speed of the feed auger motor is adjustable, the feeding speed can be accurately controlled, and then the effective regulation of the height of the material layer in the gasifier can be realized. At the same time, the feeding and discharging of the material can be appropriately adjusted through the gate valve, which can ensure the operation safety and flexibly control the feeding quantity at the same time.

[0040] (5) The present invention can improve and reduce the dust during the transportation of the material by the feed device of the gasifier, reduce the floor area of the feed device, and has the function of changing the dryness and humidity of the material. At the same time, it can reduce the labor intensity of the operator and make the operation of the whole system more convenient and fast. Description of the Drawings

[0041] Figure 1 It is a schematic structural diagram of a traditional up-draft fixed-bed biomass gasifier;

[0042] Figure 2 It is a schematic structural diagram of the feed device of the feed system of the up-draft fixed-bed biomass gasifier of the present invention;

[0043] Figure 3 It is a partial structural schematic diagram of the feed system of the up-draft fixed-bed biomass gasifier of the present invention;

[0044] Figure 4 It is a partial structural schematic diagram of the installation position of the level gauge of the feed system of the up-draft fixed-bed biomass gasifier of the present invention;

[0045] Figure 5 It is a partial structural schematic diagram of the feed auger of the feed system of the up-draft fixed-bed biomass gasifier of the present invention;

[0046] In the figure, 1 is the gasifier body; 2 is the conical silo; 3 is the ash pan water seal device, 31 is the rotating ash pan unit, 32 is the ash pan, and 33 is the slag chute; 4 is the biomass gas outlet; 5 is the chain conveyor; 6 is the buffer silo; 7 is the feeding auger, 71 is the trough, 72 is the rotating shaft, 73 is the spiral blade, 74 is the feeding port, 75 is the discharging port, and 76 is the driving device; 8 is the spraying system, 81 is the support plate, and 82 is the spraying unit; 9 is the feeding hopper; 10 is the feeding gate valve; 11 is the level gauge. Detailed implementation mode

[0047] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and the detailed implementation manner and specific operation process are given, but the protection scope of the present invention is not limited to the following embodiments.

[0048] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 construed as a limitation of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0049] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0050] In the following embodiments or examples, if there is no specifically described functional component or structure, it means that they are all conventional components or conventional structures adopted in the art to achieve the corresponding functions.

[0051] Embodiment 1

[0052] An up-draft fixed-bed biomass gasifier feeding system, as Figure 2-3 shown, its specific structure is as follows:

[0053] The system mainly consists of the main body of the gasifier 1, the conical silo 2, the biomass gas export device, the feeding and conveying device, and the ash pan water seal device 3. Among them, the conical silo 2 is located at the center of the top of the main body of the gasifier 1 and is used to store the biomass raw materials (materials) to be burned and gasified. The biomass gas export device includes biomass gas outlets 4 (at least 2) symmetrically arranged on both sides of the conical silo 2, and these outlets are used to export the generated biomass gas fuel. The feeding and conveying device is connected to the conical silo 2 and is responsible for conveying the biomass raw materials into the conical silo 2. In addition, the ash pan water seal device 3 is installed at the bottom of the main body of the gasifier 1 and is used to collect the ashes (biomass residues after the combustion of biomass raw materials) and form a water seal to prevent gas leakage.

[0054] The feeding and conveying device consists of a chain conveyor 5, a buffer silo 6, and a feeding auger 7. The chain conveyor 5 is responsible for conveying the materials to the buffer silo 6. Its conveying speed is relatively slow, but it has high stability and reliability and is not prone to jamming. The buffer silo 6 is used to temporarily store the materials, and then the materials are conveyed to the conical silo 2 through the feeding auger 7. A spraying system 8 is also equipped above the chain conveyor 5 to change the dryness and wetness of the materials and avoid dust flying.

[0055] In this embodiment, the materials are transported to the conical silo 2 through the feeding and conveying device, and then enter the gasifier body 1 and are burned and gasified. The gas generated after the combustion and gasification of the materials is exported through the biomass gas outlet 4, and the residues generated after the combustion and gasification of the materials are discharged through the ash pan water seal device 3. During this process, the spraying system can adjust the humidity of the materials.

[0056] Embodiment 2

[0057] An up-draft fixed-bed biomass gasifier feeding system includes the main body of the gasifier 1, the conical silo 2, the feeding and conveying device, and the ash pan water seal device 3.

[0058] The feeding and conveying device includes a chain conveyor 5, a buffer silo 6, and a feeding auger 7. The material input end of the chain conveyor 5 is connected to the feeding hopper 9 buried underground, the material output end of the chain conveyor 5 is connected to the buffer silo 6 for temporarily storing materials, the feeding port of the feeding auger 7 is connected to the buffer silo 6, and its discharging port is connected to the top of the conical silo 2. The feeding auger 7 is used to convey the materials from the buffer silo 6 into the conical silo 2.

[0059] In this embodiment, as Figure 5As shown in the figure, the feeding auger 7 includes a trough 71, a rotating shaft 72, a spiral blade 73, and a driving device 76 that provides power for the rotation of the rotating shaft 72. The rotating shaft 72 axially penetrates the trough 71. The spiral blade 73 is spirally wound around the rotating shaft 72. The feeding port 74 of the feeding auger 7 is opened at one end of the trough 71, and the discharging port 75 is opened at the other end of the trough 71. The driving device 76 is arranged at one end of the rotating shaft 72 close to the feeding port 74 of the feeding auger 7. The driving device 76 includes a motor and a speed reducer.

[0060] In this embodiment, the chain plate conveyor 5 includes an inclined lifting section with an inclination angle α of 30 - 45°, which is convenient for the efficient transportation of materials. A spraying system 8 is also equipped above the chain plate conveyor 5 to make the humidity of the materials reach between 15% - 25%. An inlet gate valve 10 for flexibly controlling the material feeding amount is arranged between the discharging port of the feeding auger 7 and the conical bin 2.

[0061] The conical bin 2 is arranged at the center of the top of the gasifier body 1. The bottom end of the conical bin 2 extends into the inner cavity of the gasifier body 1. It adopts a structure design with a narrower upper part and a wider lower part, and the cross-sectional area at the top is smaller than that at the bottom to ensure uniform material falling. Two level gauges 11 for monitoring the material height are symmetrically distributed on both sides of the inner wall at the upper end of the conical bin 2. Two biomass gas outlets 4 for leading out the biomass gas generated after the combustion of the biomass raw materials are symmetrically arranged on both sides of the conical bin 2.

[0062] The ash pan water seal device 3 is arranged at the bottom of the gasifier body 1, used for collecting ashes and forming a water seal to prevent gas leakage. The ash pan water seal device 3 is mainly composed of a rotating ash pan unit 31 and an ash pan 32. The rotating ash pan unit 31 is arranged inside the bottom end of the gasifier body 1, and the ash pan 32 is arranged on the outer periphery of the bottom end of the gasifier body 1. A gap is left between the ash pan 32 and the gasifier body 1 as a slag chute 33. The slag chute 33 is communicated with the ash pan 32, and the ash pan 32 contains water for sealing.

[0063] In this embodiment, the feeding port forms a sealed space by material seal, and the lower ash pan 32 isolates air by water seal. The entire cavity inside the gasifier body 1 is in a sealed state. At the same time, the positive pressure in the upper part of the furnace can just make the biomass gas flow out along the biomass gas outlet 4, which can ensure the good sealing of the gasifier and prevent the escape of biomass gas from causing safety accidents. The setting of the spraying system 8 can avoid the occurrence of dust and the over-temperature of the furnace body, and further enhance the safety of the combustion of biomass raw materials in the gasifier.

[0064] Embodiment 3

[0065] An up-draft fixed-bed biomass gasifier feeding system, above which a spraying system 8 is installed on the chain conveyor 5. On the basis of Embodiment 2, this system is composed of a support plate 81 and a plurality of spraying units 82 uniformly arranged on the support plate 81. The support plate 81 is horizontally installed above the chain conveyor 5, and each spraying unit 82 includes an atomizing nozzle and a PLC controller. The spraying direction of the atomizing nozzle forms an angle of 45-90° with the material conveying direction of the chain conveyor 5. A plurality of humidity sensors for detecting the humidity of the material are arranged on the chain conveyor 5. The PLC controller of the spraying unit 82 can receive the humidity signal detected by the humidity sensor and regulate the spraying intensity of the atomizing nozzle. When the detected value of the humidity sensor is less than 15%, the spraying unit 82 will increase the spraying intensity until the material humidity reaches between 15% and 25%.

[0066] In this embodiment, as Figure 4 shown, the level gauge 11 is specifically a mechanical rotary level gauge, which is vertically arranged on the wall of the conical bin 2, and the angle β between it and the wall of the conical bin 2 is 90° to ensure the accuracy of measurement.

[0067] In this embodiment, gas filtering components are provided at the biomass gas outlet 4 for filtering impurities in the gas.

[0068] The above description of the embodiments is to enable those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. An upper-suction fixed-bed biomass gasifier feeding system, characterized in that, It includes a gasifier body (1), a conical silo (2), a biomass gas export device, a feeding and conveying device, and an ash pan water seal device (3). The conical silo (2) is arranged in the middle of the top of the gasifier body (1). The biomass gas export device includes at least two biomass gas outlets (4) symmetrically distributed on both sides of the conical silo (2). The conical silo (2) is connected to the feeding and conveying device, and the ash pan water seal device (3) is arranged at the bottom end of the gasifier body (1). The feeding and conveying device includes a chain conveyor (5), a buffer silo (6), and a feeding auger (7). The chain conveyor (5) conveys materials to the buffer silo (6), and then conveys them to the conical silo (2) through the feeding auger (7). A spraying system (8) is arranged above the chain conveyor (5).

2. The feeding system of an up-draft fixed-bed biomass gasifier according to claim 1, characterized in that The chain conveyor (5) includes an inclined lifting section. The inclination angle α of the inclined lifting section is 30 - 45°. The material input end of the chain conveyor (5) is connected to a feeding hopper (9), and the feeding hopper (9) is buried underground.

3. The feeding system of an up-draft fixed-bed biomass gasifier according to claim 1, characterized in that, The chain conveyor (5) is provided with a plurality of humidity sensors for detecting the humidity of materials. The spraying system (8) includes a support plate (81) and a plurality of spraying units (82) evenly distributed on the support plate (81). The support plate (81) is horizontally installed above the chain conveyor (5). The spraying unit (82) includes an atomizing nozzle and a PLC controller. The PLC controller can receive the humidity signal detected by the humidity sensor and regulate the spraying intensity of the spraying unit (82). When the detection value of the humidity sensor < 15%, the spraying unit (82) increases the spraying intensity until the material humidity reaches between 15% - 25%.

4. The feeding system of an up-draft fixed-bed biomass gasifier according to claim 3, wherein The spraying direction of the atomizing nozzle forms an angle of 45 - 90° with the material conveying direction of the chain conveyor (5).

5. The feeding system of an up-draft fixed-bed biomass gasifier according to claim 1, wherein The ash pan water seal device (3) includes a rotating ash pan unit (31) and an ash basin (32). The rotating ash pan unit (31) is arranged inside the bottom end of the gasifier body (1). The ash basin (32) is arranged on the outer periphery of the bottom end of the gasifier body (1). There is a gap between the ash basin (32) and the gasifier body (1), and the gap serves as a slag chute (33). The slag chute (33) is communicated with the ash basin (32), and the ash basin (32) contains water for sealing.

6. The feeding system of an up-draft fixed-bed biomass gasifier according to claim 1, wherein The buffer silo (6) is respectively connected to the material output end of the chain conveyor (5) and the feeding port (74) of the feeding auger (7). The discharging port (75) of the feeding auger (7) is connected to the top end of the conical silo (2). A feeding gate valve (10) for controlling the material feeding amount is arranged between the discharging port (75) of the feeding auger (7) and the conical silo (2).

7. The feeding system of an up-draft fixed-bed biomass gasifier according to claim 6, characterized in that, The feeding auger (7) includes a trough (71), a rotating shaft (72) axially penetrating the trough (71), and a spiral blade (73) spirally wound around the rotating shaft (72). The feeding port (74) of the feeding auger (7) is opened at one end of the trough (71), and the discharging port (75) is opened at the other end of the trough (71). One end of the rotating shaft (72) close to the feeding port (74) of the feeding auger (7) is connected to a driving device (76) that provides power for the rotation of the rotating shaft (72). The driving device (76) includes a motor and a speed reducer.

8. The feeding system of an up-draft fixed-bed biomass gasifier according to claim 1, characterized in that, The bottom end of the conical bin (2) extends into the inner cavity of the gasifier body (1). The conical bin (2) has a structure that is narrow at the top and wide at the bottom, and the cross-sectional area at the top of the conical bin (2) is smaller than the cross-sectional area at the bottom.

9. The feeding system of an up-draft fixed-bed biomass gasifier according to claim 1, wherein, Two level gauges (11) are symmetrically distributed on both sides of the upper wall of the conical bin (2). The level gauge (11) includes a mechanical rotary level gauge. The mechanical rotary level gauge is vertically arranged on the wall of the conical bin (2), and the included angle β between it and the wall of the conical bin (2) is 90°.

10. A method for operating the feeding system of an up-draft fixed-bed biomass gasifier as described in any one of claims 1-9, characterized in that, The material is transported to the conical bin (2) by the feeding and conveying device, and then enters the gasifier body (1) and burns and gasifies. The gas generated after the material burns and gasifies is led out through the biomass gas outlet (4), and the residue generated after the material burns and gasifies is discharged through the ash pan water seal device (3). During this process, the spraying system (8) can adjust the humidity of the material.

Images