Biomass gasification feed system

Abstract

The application provides a biomass gasification feeding system, which comprises a feeding bin, a first feeder, at least two sealing mechanisms and a second feeder. The inlet of the first feeder is communicated with the feeding port of the feeding bin through a falling pipeline and a pneumatic valve. The at least two sealing mechanisms are connected in series at the outlet of the first feeder, and the adjacent two sealing mechanisms are connected through a connecting pipeline. The connecting pipeline is provided with a sealing gas inlet for connecting an external sealing gas source. The inlet of the second feeder is communicated with the outlet of the downstream sealing mechanism through a discharging pipeline, and the discharging pipeline is provided with a sealing gas inlet for communicating with the external sealing gas source. The outlet of the second feeder is communicated with the feeding port of a biomass gasification furnace. By introducing the first sealing gas into the connecting pipeline and the second sealing gas into the second feeder, the positive pressure in the sealing mechanism and the second feeder can be maintained to be higher than the preset value interval of the operating pressure of the biomass gasification furnace, so that the sealing property of the sealing mechanism and the second feeder can be improved.

Description

Technical Field

[0001] This invention relates to the field of biomass energy technology, and in particular to a biomass gasification feeding system. Background Technology

[0002] Circulating fluidized bed gasifiers (CFBGs) are common large-scale biomass utilization devices that gasify biomass fuel into combustible gases for reuse. They are characterized by large biomass processing capacity, high content of effective gas components, low tar content, and high gasification efficiency. The feeding system is a crucial component of the CFBG, playing a vital role in its stable and safe operation and operational condition regulation.

[0003] Currently, the fuel inlet of a biomass circulating fluidized bed gasifier is generally designed on the side of the furnace body. During operation, air is typically supplied from the bottom of the furnace to its interior, allowing the biomass to undergo sufficient pyrolysis and gasification within the furnace chamber to produce combustible gas. During this process, the gasification temperature inside the furnace can reach as high as 850℃, and a positive pressure of approximately 10 kPa is maintained, potentially reaching 20 kPa in extreme cases. This makes gas leakage a significant risk, thus requiring high sealing performance from the biomass circulating fluidized bed gasifier. If the feed inlet is not properly sealed, gas can easily backflow into the feed hopper. Once it accumulates to a certain concentration, contact with dust and air, combined with static electricity or other ignition sources, can easily lead to a fire or explosion. Summary of the Invention

[0004] The purpose of this invention is to provide a biomass gasification feeding system with high sealing performance that can prevent the backflow of flammable and explosive gases.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] According to one aspect of this application, a biomass gasification feeding system is provided for feeding material into a biomass gasifier, the biomass gasification feeding system comprising:

[0007] A feeding hopper for storing materials; the bottom of the feeding hopper is provided with a feeding port;

[0008] The first feeding mechanism has an inlet and an outlet. The inlet of the first feeding mechanism is connected to the feed port of the feeding bin through a discharge pipe and a pneumatic valve. The first feeding mechanism is used to transport materials.

[0009] At least two sealing mechanisms are connected in series at the outlet of the first feeding mechanism; adjacent sealing mechanisms are connected by a connecting pipe, and the connecting pipe is provided with a sealing gas inlet for connecting an external sealing gas source.

[0010] The second feeding mechanism has an inlet and an outlet. The inlet of the second feeding mechanism is connected to the outlet of the downstream sealing mechanism through a feeding pipe. The connecting pipe is provided with a sealing gas filling port, which is used to connect with an external sealing gas source. The outlet of the second feeding mechanism is connected to the feed inlet of the biomass gasifier.

[0011] Specifically, a first sealing gas is introduced into the connecting pipeline through the sealing gas inlet to maintain a positive pressure in the sealing mechanism that is higher than the preset operating pressure of the biomass gasifier. Furthermore, a second sealing gas is introduced into the second feeding mechanism through the inlet connecting pipe of the second feeding mechanism to maintain a positive pressure inside the second feeding mechanism that is higher than the preset operating pressure of the biomass gasifier. This prevents flammable and explosive gases in the biomass gasifier from flowing back into the feeding hopper when the biomass gasifier is operating normally or when pressure fluctuations occur.

[0012] In some embodiments, the flow rate of the first sealing gas introduced into the connecting pipe is negatively correlated with the flow rate of the second sealing gas introduced into the second feeding mechanism.

[0013] In some embodiments, the pressure inside the sealing mechanism is 20 kPa to 30 kPa higher than the operating pressure of the biomass gasifier;

[0014] The pressure inside the second feeding mechanism is 10 kPa to 20 kPa higher than the operating pressure of the biomass gasifier.

[0015] In some embodiments, the pressure of the first sealing gas inside the sealing mechanism is positively correlated with the flow rate of the first sealing gas entering the biomass gasifier;

[0016] The pressure of the second sealing gas inside the second feeding mechanism is positively correlated with the flow rate of the second sealing gas entering the biomass gasifier.

[0017] In some embodiments, the gas flow rate maintaining the fluidized flow field inside the biomass gasifier includes the flow rate of the first sealing gas entering the biomass gasifier, the flow rate of the second sealing gas entering the biomass gasifier, and the flow rate of the gasifying agent introduced into the biomass gasifier.

[0018] In some embodiments, the outlet of the second feeding mechanism is connected to the inlet of the biomass gasification furnace through a feed pipe; the feed pipe is provided with a steam interface for connecting to an external steam source;

[0019] The length of the feed pipe is 30cm to 50cm.

[0020] In some embodiments, the biomass gasification feeding system further includes a controller, which is electrically connected to the pneumatic valve, the first feeding mechanism, the second feeding mechanism, and at least two of the sealing mechanisms.

[0021] The biomass feeding system also includes a temperature sensor, which is used to detect the temperature signal at the inlet of the second feeding mechanism; the temperature sensor is electrically connected to the controller, and the controller can control the opening and closing of the pneumatic valve, the first feeding mechanism, the second feeding mechanism, and at least two of the sealing mechanisms according to the temperature signal;

[0022] The biomass gasification feeding system also includes a gas detector, which is located at the top of the feeding hopper and is used to detect the concentration signal of flammable and explosive gases in the feeding hopper; the gas detector is electrically connected to the controller.

[0023] In some embodiments, the biomass gasification feeding system further includes a shut-off valve, which is connected between the outlet of the sealing mechanism located downstream and the inlet of the second feeding mechanism, and is used to control the connection and disconnection between the sealing mechanism and the second feeding mechanism;

[0024] The biomass gasification feeding system also includes an emergency shut-off valve, which is located at the outlet of the second feeding mechanism and is used to control the opening and closing of the outlet of the second feeding mechanism.

[0025] In some embodiments, the biomass gasification feeding system further includes a first dust collection device, which is connected to the outlet end of the first feeding mechanism near the outlet and is used to draw in and collect a small amount of flammable and explosive gas flowing back into the first feeding mechanism and dust generated during the material conveying process.

[0026] The biomass gasification feeding system also includes a second dust collection device, which is connected to the feeding hopper and is used to draw in and collect a small amount of flammable and explosive gases and dust generated during the feeding process.

[0027] In some embodiments, the first feeding mechanism includes an inlet end and an outlet end. The first feeding mechanism is inclined upward from the inlet end to the outlet end, such that the outlet of the first feeding mechanism is located above the inlet of the first feeding mechanism and is connected to the inlet through a cylindrical sealed cavity that can accommodate materials.

[0028] The angle between the first feeding mechanism and the horizontal plane is 0° to 20°.

[0029] In some embodiments, a material loosening device is provided at the bottom of the feeding hopper for rolling the material in the feeding hopper to the feeding port;

[0030] The feeding hopper is also equipped with a vibrator, which loosens the material in the feeding hopper by means of high-pressure gas pulse or medium- and high-frequency mechanical vibration.

[0031] In some embodiments, the first feeding mechanism is a screw feeding mechanism;

[0032] The second feeding mechanism is a water-cooled spiral feeding mechanism;

[0033] The sealing mechanism is a high-sealing rotary valve.

[0034] In some embodiments, the second feeding mechanism includes a conveying pipeline connecting the downstream sealing mechanism and the biomass gasifier, the conveying pipeline being inclined downward toward the biomass gasifier from the sealing mechanism;

[0035] The angle between the delivery pipeline and the horizontal plane is greater than or equal to 70°.

[0036] As can be seen from the above technical solution, the present invention has at least the following advantages and positive effects:

[0037] In the biomass gasification feeding system of this application, at least two sealing mechanisms are connected in series between the outlet of the first feeding mechanism and the inlet of the second feeding mechanism. These mechanisms facilitate the forward transport of material from the feeding hopper to the biomass gasifier and prevent flammable and explosive gases from the biomass gasifier from flowing back through the sealing mechanisms into the first feeding mechanism, or even into the feeding hopper, thus preventing a fire or explosion. In other words, the sealing mechanisms enable unidirectional material transport; any material passing through the sealing mechanism can only be transported from the inlet to the outlet, but not from the outlet back into the inlet. This provides a sealing effect, preventing combustible gases from the biomass gasifier from entering the sealing mechanism during material transport. Therefore, the sealing mechanisms serve as a measure to prevent the backflow of combustible gases in the biomass gasification feeding system, thereby improving the safety and reliability of the system.

[0038] Simultaneously, a first sealing gas is introduced into the connecting pipeline through the sealing gas inlet to maintain a positive pressure in the sealing mechanism that is higher than the preset value range of the biomass gasifier's operating pressure. Furthermore, a second sealing gas is introduced into the second feeding mechanism through the sealing gas inlet to maintain a positive pressure in the second feeding mechanism that is higher than the preset value range of the biomass gasifier's operating pressure. This not only improves the sealing performance of the sealing mechanism to prevent flammable and explosive gases in the biomass gasifier from backflowing into the first feeding mechanism and feeding hopper during normal operation or when pressure fluctuations occur in the biomass gasifier, but also overcomes the pressure of combustible gases in the biomass gasifier, allowing materials to pass smoothly through the sealing mechanism and the second feeding mechanism, thereby improving the continuity and stability of material conveying. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the biomass feeding system in this embodiment.

[0040] Figure 2 This is a schematic diagram of the sealing mechanism in this embodiment.

[0041] The annotations in the attached figures are explained as follows:

[0042] 100. Biomass gasification feeding system; 1. Feed hopper; 11. Feed inlet; 12. Loading inlet; 2. First feeding mechanism; 21. Inlet end; 22. Outlet end; 3. Sealing mechanism; 3a. First sealing mechanism; 3b. Second sealing mechanism; 31. Outer shell; 32. Impeller; 321. Blade; 33. Sealing strip; 4. Second feeding mechanism; 51. Discharge pipe; 52. Connecting pipe; 521. Sealing gas inlet; 53. Conveying pipe; 54. Discharge pipe ; 541, Sealed gas inlet; 55, Feed pipe; 551, Steam interface; 61, Pneumatic valve; 62, First regulating valve; 63, Second regulating valve; 64, Shut-off valve; 65, Emergency shut-off valve; 7, First dust collection device; 8, Second dust collection device; 9, Material loosening device; 10, Vibrator; 20, First material detector; 30, Second material detector; 40, Third material detector; 50, Temperature sensor; 60, Gas detector; 200, Biomass gasification furnace. Detailed Implementation

[0043] Typical embodiments embodying the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various variations in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the present invention.

[0044] In the description of this application, it should be understood that, in the embodiments shown in the accompanying drawings, the indications of direction or positional relationships (such as up, down, left, right, front, and back) are merely for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. These descriptions are appropriate when these elements are in the positions shown in the accompanying drawings. If the description of the positions of these elements changes, these directional indications also change accordingly.

[0045] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0046] This application provides a biomass feeding system for conveying material to a biomass gasifier located downstream therefrom. The biomass gasifier is used to gasify the material to generate combustible gas.

[0047] Specifically, the biomass gasifier has a feed inlet for connecting the interior of the biomass gasifier with the biomass gasification feed system.

[0048] The biomass gasification feeding system conveys biomass raw materials. For example, biomass raw materials can be biomass pellets, biomass briquettes, wood chips, bark chips, pulverized material, etc. Because these biomass raw materials have high surface friction and poor flowability, they are prone to arching and blockage during conveying. Therefore, this application optimizes and improves the structure of the biomass gasification feeding system to enhance the smoothness, continuity, and stability of material conveying.

[0049] The following detailed description of specific embodiments of the biomass feeding system of this application, in conjunction with the accompanying drawings, provides a comprehensive overview.

[0050] Figure 1 This is a schematic diagram of the biomass feeding system in this embodiment.

[0051] refer to Figure 1The biomass gasification feeding system 100 includes a feeding silo 1, a first feeding mechanism 2, at least two sealing mechanisms 3, and a second feeding mechanism 4. The feeding silo 1 is used to store materials. A feeding port 11 is provided at the bottom of the feeding silo 1. The first feeding mechanism 2 has an inlet and an outlet. The inlet of the first feeding mechanism 2 is connected to the feeding port 11 of the feeding silo 1 via a discharge pipe 51 and a pneumatic valve 61. The first feeding mechanism 2 is used to transport materials. At least two sealing mechanisms 3 are connected in series at the outlet of the first feeding mechanism 2. Adjacent sealing mechanisms 3 are connected via a connecting pipe 52. The connecting pipe 52 is provided with a sealing gas inlet 521, which is used to connect to an external sealing gas source. The second feeding mechanism 4 has an inlet and an outlet. The inlet of the second feeding mechanism 4 is connected to the outlet of the downstream sealing mechanism 3 via a discharge pipe 54. The discharge pipe 54 is provided with a sealing gas filling port 541, which is used to connect to an external sealing gas source. The outlet of the second feeding mechanism 4 is connected to the inlet of the biomass gasifier 200. First sealing gas is introduced into the connecting pipe 52 through the sealing gas inlet 521 to maintain a positive pressure in the sealing mechanism 3 that is higher than a preset operating pressure of the biomass gasifier 200. Second sealing gas is introduced into the second feeding mechanism 4 through the sealing gas inlet 541 to maintain a positive pressure inside the second feeding mechanism 4 that is higher than the preset operating pressure of the biomass gasifier 200. This prevents flammable and explosive gases inside the biomass gasifier 200 from flowing back into the first feeding mechanism 2 and the feeding bin 1 during normal operation of the biomass gasifier 200 or when pressure fluctuations occur.

[0052] In the aforementioned biomass gasification feeding system 100, at least two sealing mechanisms 3 are connected in series between the outlet of the first feeding mechanism 2 and the inlet of the second feeding mechanism 4. These mechanisms facilitate the forward transport of material from the feeding hopper 1 to the biomass gasifier 200 and prevent flammable and explosive gases from the biomass gasifier 200 from flowing back through the sealing mechanisms 3 into the first feeding mechanism 2, or even into the feeding hopper 1, thus preventing a fire or explosion. In other words, the sealing mechanisms 3 enable unidirectional material transport; any material passing through the sealing mechanism 3 can only be transported from the inlet to the outlet, but not from the outlet back into the inlet. This provides a sealing effect, preventing combustible gases from entering the biomass gasifier 200 during material transport. Therefore, the sealing mechanisms 3 serve as a measure to prevent the backflow of combustible gases in the biomass gasification feeding system 100, thereby improving the safety and reliability of the system.

[0053] Simultaneously, a first sealing gas is introduced into the connecting pipe 52 through the sealing gas inlet 521. The first sealing gas can flow in the connecting pipe 52 and into the sealing mechanism 3 to maintain a positive pressure in the sealing mechanism 3 that is higher than the preset value of the operating pressure of the biomass gasifier 200. Furthermore, a second sealing gas is introduced into the second feeding mechanism 4 through the sealing gas inlet 541 to maintain a positive pressure in the second feeding mechanism 4 that is higher than the preset value of the operating pressure of the biomass gasifier 200. This can improve the sealing performance of the sealing mechanism 3 and the second feeding mechanism 4, preventing flammable and explosive gases in the biomass gasifier 200 from backflowing into the first feeding mechanism 2 and the feeding bin 1 when the biomass gasifier 200 is operating normally or when pressure fluctuations occur. It can also overcome the pressure of combustible gases in the biomass gasifier 200, allowing the material to pass smoothly through the sealing mechanism 3 and the second feeding mechanism 4, thereby improving the continuity and stability of material conveying.

[0054] refer to Figure 1 The feed hopper 1 is hollow inside and used to store materials. A feed inlet 12, communicating with the interior of the feed hopper 1, is located at the top of the feed hopper 1 for adding materials. Specifically, the feed inlet 12 is located at the top of the feed hopper 1. The biomass gasification feeding system 100 also includes a conveying device connected to the feed inlet 12 of the feed hopper 1 to transport materials into the feed hopper 1.

[0055] The bottom of the feeding bin 1 is provided with a feeding port 11 that communicates with its interior, which is used to convey the material inside the feeding bin 1 to the outside.

[0056] The feeding bin 1 can be a cylindrical shape, a single square shape, a combination of multiple square shapes, or a conical structure, or it can be a flat-bottomed sweeping bin.

[0057] For example, the feeding bin 1 includes a cylindrical section and a conical section. The inner diameter of the cylindrical section is consistent from top to bottom. The conical section is connected to the bottom of the cylindrical section, and the feed port 11 is located at the bottom of the conical section. The inner diameter of the conical section gradually decreases from top to bottom. That is, by setting the feeding bin 1 to a structure with different wall angles, it is beneficial for material to fall, preventing arching and blockage problems, and improving the smoothness and continuity of material discharge from the feeding bin 1.

[0058] Alternatively, the feed bin 1 may consist only of a cylindrical section, that is, the bottom of the feed bin 1 is flat, in which case the feed port 11 is located at the bottom of the cylindrical section. Alternatively, the feed bin 1 may consist only of a conical section.

[0059] The specific structural configuration of the feed hopper 1 depends on the needs.

[0060] refer to Figure 1The first feeding mechanism 2 has an inlet and an outlet. The inlet of the first feeding mechanism 2 is connected to the feed port 11 of the feeding bin 1 through the discharge pipe 51 and the pneumatic valve 61. The first feeding mechanism 2 is used to transport materials. Specifically, the pneumatic valve 61 is installed on the discharge pipe 51 and is used to control the opening and closing of the discharge pipe 51 to realize the on / off control between the inlet of the first feeding mechanism 2 and the feed port 11 of the feeding bin 1.

[0061] In this embodiment, the first feeding mechanism 2 includes an inlet end 21 for feeding and an outlet end 22 for discharging. The first feeding mechanism 2 is inclined upward from the inlet end 21 to the outlet end 22, so that the outlet of the first feeding mechanism 2 is located above the inlet of the first feeding mechanism 2 and is connected to the inlet through a cylindrical sealed cavity that can accommodate materials. This allows the material accumulated inside the first feeding mechanism 2 to form a certain material seal, that is, to form a seal against backflow of flammable gas through the retention of material, so as to prevent flammable and explosive gases from flowing back from the outlet of the first feeding mechanism 2 through the inlet of the first feeding mechanism 2 into the feeding bin 1 and causing a fire or explosion. In other words, the above design can be used as a first measure to prevent flammable and explosive gases from flowing back into the feeding bin 1, so as to improve the safety and reliability of the biomass gasification feeding system 100.

[0062] The inclination angle of the first feeding mechanism 2 is determined based on the characteristic parameters of the biomass material. For example, the angle between the first feeding mechanism 2 and the horizontal plane can be 0° to 20°, so that the material accumulated inside the first feeding mechanism 2 can form a better material sealing effect.

[0063] In this embodiment, the first feeding mechanism 2 is a screw feeder. Specifically, the first feeding mechanism 2 is a multi-shaft screw feeder with two, three, or five shafts, thereby achieving uniform material discharge and preventing material accumulation and arching inside the first feeding mechanism 2. In other embodiments, the first feeding mechanism 2 may also be a single-shaft screw feeder. It should be noted that the terms "multi-shaft" and "single-shaft" here refer to the number of screw conveying shafts included in the first feeding mechanism 2.

[0064] In this embodiment, the first feeding mechanism 2 adopts frequency conversion control to adjust its operating frequency. On the one hand, the feeding rate of the first feeding mechanism 2 can be adjusted according to the load of the biomass gasification feeding system 100 and the biomass gasifier 200, thereby adjusting the feeding rate of the biomass gasifier 200. On the other hand, the frequency conversion control of the first feeding mechanism 2 will cause it to vibrate, ensuring uniform, continuous, and stable feeding. Furthermore, the vibration generated by the first feeding mechanism 2 during operation can also be transmitted to the feeding bin 1, which can loosen the material in the feeding bin 1, allowing the material in the feeding bin 1 to fall smoothly to the feed port 11, thereby improving the continuity and stability of the feed output from the feeding bin 1.

[0065] In this embodiment, at least two sealing mechanisms 3 are connected in series at the outlet of the first feeding mechanism 2.

[0066] Two adjacent sealing mechanisms 3 are connected by a connecting pipe 52. Specifically, each sealing mechanism 3 has an inlet and an outlet, wherein, in two adjacent sealing mechanisms 3, the connecting pipe 52 connects the outlet of the upstream sealing mechanism 3 and the inlet of the downstream sealing mechanism 3.

[0067] Specifically, taking two sealing mechanisms as an example, the two sealing mechanisms 3 are a first sealing mechanism 3a and a second sealing mechanism 3b, wherein the first sealing mechanism 3a and the second sealing mechanism 3b are arranged upstream and downstream. The first sealing mechanism 3a is connected to the outlet of the first feeding mechanism 2 through the material conveying pipe 53. The inlet of the second sealing mechanism 3b is connected to the outlet of the first sealing mechanism 3a through the connecting pipe 52.

[0068] The diameter of the conveying pipeline 53 gradually increases from the first feeding mechanism 2 to the first sealing mechanism 3a to prevent material from accumulating and arching inside, thereby further improving the smoothness and stability of material conveying. In this embodiment, a sealing gas inlet 521 is provided on the connecting pipe 52. The sealing gas inlet 521 is used to connect to an external sealing gas source so that the first sealing gas can be introduced into the connecting pipe 52 through the sealing gas inlet 521. This allows the first sealing gas to fill the interior of the sealing mechanism 3, thereby increasing the pressure inside the sealing mechanism 3. Furthermore, this can maintain a positive pressure in the sealing mechanism 3 that is higher than the preset operating pressure of the biomass gasifier 200. Since gas has the characteristic of moving from high pressure to low pressure, the above design can suppress the tendency of flammable and explosive gases to flow back into the sealing mechanism 3 through the feed inlet, thereby reducing the probability of syngas backflow and leakage inside the biomass gasifier 200. This prevents flammable and explosive gases inside the biomass gasifier 200 from backflowing into the first feeding mechanism 2 and the feeding bin 1 when the biomass gasifier 200 is operating normally or when pressure fluctuations occur. That is, the pressure inside each sealing mechanism 3 is negatively correlated with the amount of syngas backflow in the biomass gasifier 200. The higher the pressure inside each sealing mechanism 3, the lower the amount of flammable and explosive gas backflow in the biomass gasifier 200.

[0069] Meanwhile, in this embodiment, by introducing a first sealing gas into the connecting pipe 52 between two adjacent sealing mechanisms 3, the first sealing gas can enter and fill the interior of the sealing mechanism 3 through the inlet or outlet of the sealing mechanism 3, so that at least two sealing mechanisms 3 form a multi-stage seal. This allows at least two sealing mechanisms 3 to cooperate to constitute a second measure of the biomass gasification feeding system 100 to prevent flammable and explosive gases from backflowing into the feed hopper 1, thereby further improving the safety and reliability of the biomass gasification feeding system 100.

[0070] Specifically, during the process of introducing the first sealing gas into the sealing gas inlet 521, the first sealing gas will split into two branches in the connecting pipe 52. One branch flows into the first sealing mechanism 3a and the other branch flows into the second sealing mechanism 3b. This allows the first sealing gas to fill the interior of the first sealing mechanism 3a and the second sealing mechanism 3b, thereby increasing the pressure inside the first sealing mechanism 3a and the second sealing mechanism 3b. Furthermore, this allows the first sealing mechanism 3a and the second sealing mechanism 3b to maintain a positive pressure higher than the preset value of the operating pressure of the biomass gasifier 200.

[0071] The first sealing gas mentioned above can be a high-pressure inert gas or a high-pressure steam.

[0072] In this embodiment, each sealing gas inlet 521 is equipped with a first regulating valve 62 for controlling the opening and closing of the sealing gas inlet 521 and adjusting the opening degree of the sealing gas inlet 521. The sealing performance of the sealing mechanism 3 is a variable value. As the flow rate of the first sealing gas increases, the internal pressure of the sealing mechanism 3 increases, and the sealing performance increases. However, the amount of first sealing gas escaping from the inlet and outlet of the sealing mechanism 3 also increases, meaning the consumption of the first sealing gas increases. In other words, the flow rate of the first sealing gas is positively correlated with the consumption of the first sealing gas.

[0073] Here, the consumption of the first sealing gas refers to the portion of the first sealing gas that escapes upstream from the inlet of the upstream sealing mechanism 3 or downstream from the outlet of the downstream sealing mechanism 3. The consumed portion of the first sealing gas flows into the biomass gasifier 200 to serve as a component of the gas that maintains the fluidized flow field within the biomass gasifier 200. At this time, the pressure of the first sealing gas inside the sealing mechanism 3 is positively correlated with the flow rate of the first sealing gas entering the biomass gasifier 200. Therefore, by providing a first regulating valve 62 at the sealing gas inlet 521, the flow rate of the first sealing gas entering the sealing mechanism 3 can be adjusted by operating the first regulating valve 62, thereby optimizing the sealing performance of the biomass gasification feeding system 100.

[0074] In this embodiment, the pressure within each sealing mechanism 3 is 20 kPa to 30 kPa higher than the operating pressure of the biomass gasifier 200. This pressure difference can suppress the tendency of flammable and explosive gases to flow backward through the feed inlet to the sealing mechanism 3, thereby reducing the probability of backflow leakage of gas maintaining the fluidized flow field inside the biomass gasifier 200. The backflow leakage rate of gas maintaining the fluidized flow field can be controlled below 1000 PPM (parts per million). Furthermore, the consumption of the first sealing gas can be reduced, and the consumption of the first sealing gas can be controlled below 200 m³. 3 / h and below.

[0075] Figure 2 This is a schematic diagram of the sealing mechanism 3 in this embodiment.

[0076] refer to Figure 2 In this embodiment, the sealing mechanism 3 employs a high-sealing rotary valve with a leakage rate in the PPM range. Specifically, the sealing mechanism 3 includes a housing 31 and an impeller 32 disposed inside the housing 31. The impeller 32 is rotatably connected to the housing 31 at both axial ends, allowing it to rotate relative to the housing 31. The impeller 32 includes a plurality of blades 321 arranged at circumferential intervals. Adjacent blades 321 and the housing 31 enclose a material cavity for holding material.

[0077] In practical applications, during normal feeding of the biomass gasifier 200, the impeller 32 rotates along its axial direction and in the same direction, keeping the sealing mechanism 3 in the activated state. As the impeller 32 rotates, at least one material chamber aligns with the inlet of the sealing mechanism 3 to receive material, and simultaneously, at least one material chamber aligns with the outlet of the sealing mechanism 3, allowing material to fall to the outlet, thus achieving unidirectional material conveying. When the biomass gasifier 200 does not require feeding, the impeller 32 of the sealing mechanism 3 stops rotating, which is equivalent to the sealing mechanism 3 being in the closed state.

[0078] In this embodiment, a soft seal can be used between the impeller 32 and the outer casing 31. This can be achieved by placing a sealing strip 33 on the outer periphery of the impeller 32, allowing the sealing strip 33 to contact the inner peripheral wall of the outer casing 31, thus achieving a complete seal between the impeller 32 and the outer casing 31. The sealing strip 33 can be detachably connected to the impeller 32 for easy replacement. Specifically, the sealing strip 33 has a through hole, and the impeller 32 has a through hole. Fasteners are inserted through both the through hole and the through hole to secure the sealing strip 33 to the impeller 32. The through hole and / or the through hole are oblong, allowing the fasteners to move within them. This allows adjustment of the fastener's position within the oblong hole based on the wear of the sealing strip 33, thereby adjusting the gap between the sealing strip 33 and the inner peripheral wall of the outer casing 31 to ensure the sealing performance of the sealing mechanism 3.

[0079] In other embodiments, a hard seal can also be used between the impeller 32 and the housing 31. In this case, a dynamic seal redundancy is left between the outer periphery of the impeller 32 and the inner peripheral wall of the housing 31 to avoid friction between the radial outer periphery of the impeller 32 and the inner peripheral wall of the housing 31 during rotation, which could easily cause wear of the impeller 32 and ensure the integrity of the impeller 32. The dynamic seal redundancy is filled with material to achieve a material seal between the radial outer periphery of the impeller 32 and the inner peripheral wall of the housing 31, thereby improving the sealing performance of the sealing mechanism 3. Specifically, the distance between the outer periphery of the impeller 32 and the inner peripheral wall of the housing 31 is 0.03–0.05 mm.

[0080] refer to Figure 1 In this embodiment, the second feeding mechanism 4 is used to convey materials. The second feeding mechanism 4 adopts a water-cooled spiral feeding mechanism. Specifically, the second feeding mechanism 4 can be a multi-axis water-cooled spiral feeding mechanism with two, three, or five axes, thereby achieving uniform material discharge and preventing material accumulation and arching inside the second feeding mechanism 4. In other embodiments, the second feeding mechanism 4 can also be a single-axis water-cooled spiral feeding mechanism. It should be noted that the terms "multi-axis" and "single-axis" here refer to the number of spiral conveying shafts included in the second feeding mechanism 4.

[0081] Specifically, the second feeding mechanism 4 adopts a cantilevered water-cooled spiral feeding mechanism.

[0082] In this embodiment, the second feeding mechanism 4 has an inlet and an outlet. The inlet of the second feeding mechanism 4 is connected to the outlet of the downstream sealing mechanism 3. Specifically, the inlet of the second feeding mechanism 4 is connected to the outlet of the second sealing mechanism 3b via a discharge pipe 54.

[0083] In this embodiment, the feeding pipeline 54 is provided with a sealed gas inlet 541, which is used to communicate with an external sealed gas source. This allows the second sealed gas to be supplied to the interior of the second feeding mechanism 4 through the sealed gas inlet 541. This allows the second sealed gas to fill the interior of the second feeding mechanism 4, thereby increasing the pressure inside the second feeding mechanism 4. Furthermore, this maintains a positive pressure in the second feeding mechanism 4 that is higher than the preset operating pressure of the biomass gasifier 200, thereby suppressing the tendency of flammable and explosive gases to flow back into the second feeding mechanism 4 through the feed inlet. This reduces the probability of gas backflow leakage inside the biomass gasifier 200 that maintains the fluidized flow field, and prevents flammable and explosive gases inside the biomass gasifier 200 from backflowing into the sealing mechanism 3, the first feeding mechanism 2, and the feeding bin 1 when the biomass gasifier 200 is operating normally or when pressure fluctuations occur. In other words, this embodiment introduces a second sealing gas into the second feeding mechanism 4, allowing the gas to enter and fill the interior of the second feeding mechanism 4. This enables the second feeding mechanism 4 to constitute a third layer of protection for the biomass gasification feeding system 100, preventing flammable and explosive gases from backflowing into the feeding hopper 1, thereby further improving the safety and reliability of the biomass gasification feeding system 100. Furthermore, introducing the second sealing gas into the second feeding mechanism 4 also loosens the material inside, improving the stability and smoothness of material conveying by the second feeding mechanism 4.

[0084] The second sealing gas mentioned above can be a high-pressure inert gas or a high-pressure steam.

[0085] In this embodiment, a second regulating valve 63 is provided at the sealed gas inlet 541 to control the opening and closing of the sealed gas inlet 541 and to adjust the opening degree of the sealed gas inlet 541. Similarly, as described above, the amount of second sealing gas supplied is positively correlated with the amount of second sealing gas consumed. The amount of second sealing gas consumed refers to the portion of the second sealing gas that escapes downstream from the outlet of the second feeding mechanism 4. The consumed portion of the second sealing gas flows into the biomass gasifier 200 to serve as a component of the gas maintaining the fluidized flow field inside the biomass gasifier 200. At this time, the pressure of the second sealing gas inside the second feeding mechanism 4 is also positively correlated with the flow rate of the second sealing gas entering the biomass gasifier 200. Therefore, by providing the second regulating valve 63 at the sealed gas inlet 541, the flow rate of the second sealing gas entering the sealing mechanism 3 can be adjusted by operating the second regulating valve 63, thereby optimizing the sealing performance of the biomass gasification feeding system 100.

[0086] That is, the gas maintaining the fluidized flow field inside the biomass gasifier 200 mentioned above includes the flow rate of the first sealing gas entering the biomass gasifier 200, the flow rate of the first sealing gas entering the biomass gasifier 200, and the flow rate of the gasifying agent. Among them, the gasifying agent is used for the gasification reaction of the material.

[0087] In this embodiment, the flow rate of the first sealing gas introduced into the sealing gas inlet 521 is negatively correlated with the flow rate of the second sealing gas introduced into the sealing gas filling port. In practical applications, while ensuring that the total gas flow rate maintaining the fluidized flow field inside the biomass gasifier 200 is constant, the flow rates of the first and second sealing gases are adjusted by regulating the opening of the first regulating valve 62 and the second regulating valve 63, thereby regulating the consumption of the first and second sealing gases. Under the premise of ensuring that the sealing mechanism 3 and the second feeding mechanism 4 have a pressure higher than the operating pressure inside the biomass gasifier 200, the flow rate of the first and second sealing gases entering the biomass gasifier 200 is reduced, thereby ensuring the flow rate of the gasifying agent entering the biomass gasifier 200, increasing the ratio of the gasifying agent in the gas flow rate maintaining the fluidized flow field, improving the reaction efficiency inside the biomass gasifier 200, and improving the material gasification efficiency inside the biomass gasifier 200.

[0088] In this embodiment, the pressure inside the second feeding mechanism 4 is 10 kPa to 20 kPa higher than the operating pressure of the biomass gasifier 200. Since gas has the characteristic of moving from high pressure to low pressure, this embodiment sets the pressure inside the second feeding mechanism 4 to be lower than the pressure inside the sealing mechanism 3. The pressure difference between the two can further suppress the backflow of flammable and explosive gases from the biomass gasifier 200 into the first feeding mechanism 2 or even the feeding hopper 1, thus ensuring the stability and safety of the biomass gasification feeding system 100.

[0089] In this embodiment, the biomass gasification feeding system 100 further includes a shut-off valve 64, which is connected between the outlet of the downstream sealing mechanism 3 and the inlet of the second feeding mechanism 4. The shut-off valve 64 is used to control the on / off connection between the sealing mechanism 3 and the second feeding mechanism 4. Specifically, the shut-off valve 64 is located on the discharge pipeline 54 and is positioned above the sealed gas filling port 541.

[0090] The outlet of the second feeding mechanism 4 is connected to the inlet of the biomass gasifier 200. Specifically, the outlet of the second feeding mechanism 4 is connected to the inlet of the biomass gasifier 200 through the feed pipe 55.

[0091] In this embodiment, the length of the feed pipe 55 is 30cm to 50cm. During feeding, the feed pipe 55 is filled with material, which can act as a material seal and insulate against heat radiation, preventing excessive temperature from affecting the normal operation of the second feeding mechanism 4, thus ensuring the normal use of the second feeding mechanism 4. It should be noted that the length of the feed pipe 55 here refers to the length of the internal cavity of the feed pipe 55 from the outlet of the first feeding mechanism 2 to the feed inlet of the biomass gasifier 200, which is 30cm to 50cm.

[0092] The feed pipe 55 is equipped with a steam interface 551, which is used to connect with an external steam source so that steam can be transported through the steam interface 551 into the feed pipe 55 to react with the material at the feed inlet of the biomass gasifier to produce carbon monoxide and hydrogen, thereby avoiding blockage of the feed inlet of the biomass gasifier.

[0093] In this embodiment, an emergency shut-off valve 65 is provided at the outlet of the second feeding mechanism 4 to control the opening and closing of the outlet of the second feeding mechanism 4. In other embodiments, the emergency shut-off valve 65 may also be provided on the feed pipe 55 to control the opening and closing of the feed pipe 55. It should be noted that, in this case, the length of the internal cavity of the feed pipe 55 from the emergency shut-off valve 65 to the feed inlet of the biomass gasifier 200 is 30cm to 50cm, so as to provide sufficient space for the biomass coke reaction of the material at the feed inlet.

[0094] In other embodiments, the second feeding mechanism 4 includes a conveying pipeline connecting the downstream sealing mechanism 3 and the biomass gasifier 200. Specifically, the second sealing mechanism 3b is directly connected to the biomass gasifier 200 through the conveying pipeline. In this case, a gas inlet is provided on the conveying pipeline, and the gas inlet is connected to an external sealing gas source. The conveying pipeline slopes downwards from the sealing mechanism 3 towards the biomass gasifier 200, achieving a better feeding effect. Specifically, the angle between the conveying pipeline and the horizontal plane is greater than or equal to 70°.

[0095] In this embodiment, the biomass gasification feeding system 100 further includes a first dust collection device 7. The first dust collection device 7 is connected to the outlet end 22 of the first feeding mechanism 2 near the outlet and is used to suck up and collect a small amount of flammable and explosive gases flowing back into the first feeding mechanism 2 and dust generated during the feeding process, so as to prevent flammable and explosive gases and dust generated during the feeding process from flowing back into the feeding hopper 1. That is, the first dust collection device 7 can serve as a fourth measure to prevent flammable and explosive gases from flowing back into the feeding hopper 1, and can cooperate with the first feeding mechanism 2, the sealing mechanism 3, and the second feeding mechanism 4 to further improve the safety and reliability of the biomass gasification feeding system 100.

[0096] Specifically, the first dust collection device 7 includes a suction pump and a filter element. The suction pump has a suction port and an outlet, with the suction port connected to the outlet end 22 of the first feeding mechanism 2. The filter element is located at the outlet of the suction pump and is used to filter and collect dust generated during the material conveying process. In practical applications, the suction pump extracts flammable and explosive gases that have backflowed into the first feeding mechanism 2, as well as dust generated during the material conveying process, through the suction port. Under the action of the filter element, the dust is collected, while the flammable and explosive gases are discharged through the outlet for subsequent centralized processing.

[0097] In this embodiment, the first dust collection device 7 can be a bag filter dust collection mechanism.

[0098] The biomass gasification feeding system 100 also includes a second dust collection device 8, which is connected to the feed hopper 1 and is used to extract and collect small amounts of flammable and explosive gases and dust generated during the feeding process. The structure of the second dust collection device 8 is the same as that of the first dust collection device 7, as described above.

[0099] In this embodiment, the biomass gasification feeding system 100 further includes a loosening device 9, which is located at the bottom of the feeding hopper 1 and is used to roll the material in the feeding hopper 1 to the feeding port 11 to assist in feeding. For example, the loosening device 9 can roll the material in the feeding hopper 1 to the feeding port 11 in a spiral manner.

[0100] The loosening device 9 can be arranged horizontally or at an angle. Depending on the size of the feeding bin 1, it can be arranged as a single piece or in combination of multiple pieces.

[0101] The biomass gasification feeding system 100 may further include a vibrator 10, which is installed on the feeding hopper 1. The vibrator 10 loosens the material in the feeding hopper 1 through high-pressure gas pulses or medium-to-high frequency mechanical vibration. Under the action of external force, the material in the feeding hopper 1 can fall smoothly to the feed inlet 11 and pass smoothly through the feed inlet 11, thus avoiding material accumulation, arching, and blockage at the feed inlet 11 of the feeding hopper 1, thereby ensuring the continuity, stability, and reliability of material conveying in the biomass gasification feeding system 100. Specifically, the vibrator 10 is located at the lower end of the feeding hopper 1 near the feed inlet 11 to improve the loosening effect of the vibrator 10.

[0102] In this embodiment, the vibrator 10 can be one of an electromagnetic vibrator, an electric vibrator, or a pneumatic vibrator.

[0103] The biomass gasification feeding system 100 also includes a controller, which is electrically connected to the pneumatic valve 61, the first feeding mechanism 2, the sealing mechanism 3, the second feeding mechanism 4, the first regulating valve 62, the second regulating valve 63, the shut-off valve 64, the emergency shut-off valve 65, the first dust collection device 7, the second dust collection device 8, the loosening device 9, and the vibrator 10, and is able to control the opening and closing of the pneumatic valve 61, the first feeding mechanism 2, the sealing mechanism 3, the second feeding mechanism 4, the first regulating valve 62, the second regulating valve 63, the shut-off valve 64, the emergency shut-off valve 65, the first dust collection device 7, the second dust collection device 8, the loosening device 9, and the vibrator 10.

[0104] The controller is also connected to the conveying equipment via electrical signals to control the opening and closing of the conveying equipment, so as to realize the automatic feeding of the conveying equipment to the biomass gasification feeding system 100 and improve the automation of material replenishment.

[0105] The biomass gasification feeding system 100 also includes a first material detector 20, which is located at the lower end of the feeding hopper 1 and is used to detect low material level signals in the hopper. The first material detector 20 is electrically connected to the controller and can transmit the detected low material level signal to the controller.

[0106] The biomass gasification feeding system 100 also includes a second material detector 30, which is located at the upper end of the feeding hopper 1 and is used to detect the high material level signal in the hopper. The second material detector 30 is electrically connected to the controller and can transmit the detected high material level signal to the controller.

[0107] The biomass gasification feeding system 100 also includes a third material detector 40, which is located at the upper end of the feeding hopper 1 and above the second material detector 30, and is used to detect the limit material level signal in the hopper.

[0108] Among them, the third material detector 40 mainly serves as a backup detector. It can play a backup detection role when the second material detector 30 fails, preventing the material in the feed hopper 1 from overflowing and blocking the top feed port 12 of the feed hopper 1. It can also prevent the material in the feed hopper 1 from overflowing and causing the discharge pressure at the bottom feed port 11 of the feed hopper 1, thereby ensuring the material conveying stability of the entire biomass gasification feeding system 100.

[0109] The third material detector 40 is connected to the controller via electrical signals and can transmit the detected limit level signal to the controller.

[0110] In this embodiment, the first material detector 20, the second material detector 30, the third material detector 40, the conveying equipment, and the controller cooperate to achieve automatic replenishment of the feeding hopper 1. Specifically, when only the first material detector 20 detects...

[0111] The first material detector 20, the second material detector 30, and the third material detector 40 can be one of the following: a rotary paddle level gauge, an ultrasonic level gauge, or a weighted level gauge.

[0112] The biomass gasification feeding system 100 also includes a temperature sensor 50, which is installed on the feed pipe 54 and is used to detect the temperature signal at the second inlet. The temperature sensor 50 is electrically connected to the controller, which can control the opening and closing of the pneumatic valve 61, the first feeding mechanism 2, the sealing mechanism 3, the second feeding mechanism 4, the first regulating valve 62, the second regulating valve 63, the shut-off valve 64, the emergency shut-off valve 65, the first dust collection device 7, the second dust collection device 8, the loosening device 9, and the vibrator 10 according to the temperature signal.

[0113] Specifically, in practical applications, when the temperature signal detected by the temperature sensor 50 exceeds the preset value, the controller will close the pneumatic valve 61 and the emergency shut-off valve 65, and simultaneously close the first feeding mechanism 2, the sealing mechanism 3, and the second feeding mechanism 4. It will also control the first regulating valve 62 to adjust the opening of the sealing gas inlet 521 to increase the air pressure between the sealing mechanisms 3. Furthermore, the first sealing gas also cools the backflowing gas, preventing excessive temperature from deteriorating the sealing effect of the sealing mechanism 3. Simultaneously, the controller activates the first dust collection mechanism to extract the backflowing flammable and explosive gases and dust generated during the material conveying process, preventing flammable and explosive gases from backflowing into the feeding hopper 1 and causing a fire or explosion, thereby improving the safety and reliability of the biomass gasification feeding system 100.

[0114] The biomass gasification feeding system 100 also includes a gas detector 60, which is located at the top of the feed hopper 1. The gas detector 60 is used to detect the concentration of flammable and explosive gases within the feed hopper 1, enabling real-time monitoring of the gas concentration and facilitating emergency measures when the concentration exceeds the limit. The gas detector 60 is electrically connected to the controller, allowing it to transmit the detected flammable and explosive gas concentration signal to the controller.

[0115] Specifically, the gas detector 60 includes a detection module and an alarm module. The detection module is used to detect the concentration signal of flammable and explosive gases in the feed hopper 1. The detection module and the alarm module are communicatively connected, and both the detection module and the alarm module are electrically connected to the controller. The controller has a preset flammable gas concentration value. When the flammable and explosive gas concentration signal received by the controller is higher than the flammable and explosive gas concentration value, the controller controls the alarm module to issue an alarm signal to remind the personnel.

[0116] In this embodiment, a catalytic combustion type or an infrared absorption type stationary combustible gas detector 60 can be selected as the gas detector 60 according to the composition of the flammable and explosive gas. Both can quickly and accurately detect the content of flammable and explosive gases in the feed hopper 1, ensuring the safety of the feed hopper 1. The gas detector 60 is electrically connected to the controller.

[0117] Specifically, when the concentration signal of flammable and explosive gas received by the controller is higher than the preset value, the controller controls the second dust collection device 8 to start, so as to extract the small amount of flammable and explosive gas and dust generated during the material conveying process in the feeding hopper 1, so as to ensure the safety of the feeding hopper 1.

[0118] As can be seen from the above technical solution, the present invention has at least the following advantages and positive effects:

[0119] In the biomass gasification feeding system of this application, at least two sealing mechanisms are connected in series between the outlet of the first feeding mechanism and the inlet of the second feeding mechanism. These mechanisms facilitate the forward transport of material from the feeding hopper to the biomass gasifier and prevent flammable and explosive gases from the biomass gasifier from flowing back through the sealing mechanisms into the first feeding mechanism, or even into the feeding hopper, thus preventing a fire or explosion. In other words, the sealing mechanisms enable unidirectional material transport; any material passing through the sealing mechanism can only be transported from the inlet to the outlet, but not from the outlet back into the inlet. This provides a sealing effect, preventing combustible gases from the biomass gasifier from entering the sealing mechanism during material transport. Therefore, the sealing mechanisms serve as a measure to prevent the backflow of combustible gases in the biomass gasification feeding system, thereby improving the safety and reliability of the system.

[0120] Simultaneously, a first sealing gas is introduced into the connecting pipeline through the sealing gas inlet. The first sealing gas can flow within the connecting pipeline 52 and into the sealing mechanism 3 to maintain a positive pressure higher than the preset value of the biomass gasifier's operating pressure in the sealing mechanism. Furthermore, a second sealing gas is introduced into the second feeding mechanism through the inlet to maintain a positive pressure higher than the preset value of the biomass gasifier's operating pressure inside the second feeding mechanism. This not only improves the sealing performance of the sealing mechanism to prevent flammable and explosive gases in the biomass gasifier from backflowing into the first feeding mechanism and feeding hopper during normal operation or when pressure fluctuations occur in the biomass gasifier, but also overcomes the pressure of combustible gases in the biomass gasifier, allowing the material to pass smoothly through the sealing mechanism and the second feeding mechanism, thereby improving the continuity and stability of material conveying.

[0121] Although the invention has been described with reference to several typical embodiments, it should be understood that the terminology used is illustrative and exemplary, and not restrictive. Since the invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be interpreted broadly within the spirit and scope defined by the appended claims. Therefore, all variations and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A biomass gasification feeding system for conveying materials to a biomass gasifier, characterized in that, The biomass gasification feeding system includes: A feeding hopper for storing materials; the bottom of the feeding hopper is provided with a feeding port; The first feeding mechanism has an inlet and an outlet. The inlet of the first feeding mechanism is connected to the feed port of the feeding bin through a discharge pipe and a pneumatic valve. The first feeding mechanism is used to transport materials. At least two sealing mechanisms are connected in series at the outlet of the first feeding mechanism; adjacent sealing mechanisms are connected by a connecting pipe, and the connecting pipe is provided with a sealing gas inlet for connecting an external sealing gas source. The second feeding mechanism has an inlet and an outlet. The inlet of the second feeding mechanism is connected to the outlet of the downstream sealing mechanism through a feeding pipe. The connecting pipe is provided with a sealing gas filling port, which is used to connect with an external sealing gas source. The outlet of the second feeding mechanism is connected to the feed inlet of the biomass gasifier. Specifically, a first sealing gas is introduced into the connecting pipeline through the sealing gas inlet to maintain a positive pressure in the sealing mechanism that is higher than the preset operating pressure of the biomass gasifier. Furthermore, a second sealing gas is introduced into the second feeding mechanism through the inlet connecting pipe of the second feeding mechanism to maintain a positive pressure inside the second feeding mechanism that is higher than the preset operating pressure of the biomass gasifier. This prevents flammable and explosive gases in the biomass gasifier from flowing back into the feeding hopper when the biomass gasifier is operating normally or when pressure fluctuations occur.

2. The biomass gasification feeding system according to claim 1, characterized in that, The flow rate of the first sealing gas introduced into the connecting pipeline is negatively correlated with the flow rate of the second sealing gas introduced into the second feeding mechanism.

3. The biomass gasification feeding system according to claim 2, characterized in that, The pressure inside the sealing mechanism is 20 kPa to 30 kPa higher than the operating pressure of the biomass gasifier; The pressure inside the second feeding mechanism is 10 kPa to 20 kPa higher than the operating pressure of the biomass gasifier.

4. The biomass gasification feeding system according to claim 1, characterized in that, The pressure of the first sealing gas inside the sealing mechanism is positively correlated with the flow rate of the first sealing gas entering the biomass gasifier. The pressure of the second sealing gas inside the second feeding mechanism is positively correlated with the flow rate of the second sealing gas entering the biomass gasifier.

5. The biomass gasification feeding system according to claim 4, characterized in that, The gas flow rate maintaining the fluidized flow field inside the biomass gasifier includes the flow rate of the first sealing gas entering the biomass gasifier, the flow rate of the second sealing gas entering the biomass gasifier, and the flow rate of the gasifying agent introduced into the biomass gasifier.

6. The biomass gasification feeding system according to claim 1, characterized in that, The outlet of the second feeding mechanism is connected to the inlet of the biomass gasification furnace through a feed pipe; the feed pipe is equipped with a steam interface for connecting to an external steam source. The length of the feed tube is 30cm to 50cm.

7. The biomass gasification feeding system according to claim 1, characterized in that, The biomass gasification feeding system also includes a controller, which is electrically connected to the pneumatic valve, the first feeding mechanism, the second feeding mechanism, and at least two of the sealing mechanisms. The biomass feeding system also includes a temperature sensor, which is used to detect the temperature signal at the inlet of the second feeding mechanism; the temperature sensor is electrically connected to the controller, and the controller can control the opening and closing of the pneumatic valve, the first feeding mechanism, the second feeding mechanism, and at least two of the sealing mechanisms according to the temperature signal; The biomass gasification feeding system also includes a gas detector, which is located at the top of the feeding hopper and is used to detect the concentration signal of flammable and explosive gases in the feeding hopper; the gas detector is electrically connected to the controller.

8. The biomass gasification feeding system according to claim 1, characterized in that, The biomass gasification feeding system also includes a shut-off valve, which is connected between the outlet of the sealing mechanism located downstream and the inlet of the second feeding mechanism. The shut-off valve is used to control the connection and disconnection between the sealing mechanism and the second feeding mechanism. The biomass gasification feeding system also includes an emergency shut-off valve, which is located at the outlet of the second feeding mechanism and is used to control the opening and closing of the outlet of the second feeding mechanism.

9. The biomass gasification feeding system according to claim 1, characterized in that, The biomass gasification feeding system also includes a first dust collection device, which is connected to the outlet end of the first feeding mechanism near the outlet and is used to draw in and collect a small amount of flammable and explosive gas flowing back into the first feeding mechanism and dust generated during the material conveying process. The biomass gasification feeding system also includes a second dust collection device, which is connected to the feeding hopper and is used to draw in and collect a small amount of flammable and explosive gases and dust generated during the feeding process.

10. The biomass gasification feeding system according to claim 1, characterized in that, The first feeding mechanism includes an inlet end and an outlet end. The first feeding mechanism is inclined upward from the inlet end to the outlet end, so that the outlet of the first feeding mechanism is located above the inlet of the first feeding mechanism and is connected to the inlet through a cylindrical sealed cavity that can accommodate materials. The angle between the first feeding mechanism and the horizontal plane is 0° to 20°.

11. The biomass gasification feeding system according to claim 1, characterized in that, The bottom of the feeding hopper is equipped with a material loosening device, which is used to roll the material in the feeding hopper to the feeding port; The feeding hopper is also equipped with a vibrator, which loosens the material in the feeding hopper by means of high-pressure gas pulse or medium- and high-frequency mechanical vibration.

12. The biomass gasification feeding system according to claim 1, characterized in that, The first feeding mechanism is a screw feeding mechanism; The second feeding mechanism is a water-cooled spiral feeding mechanism; The sealing mechanism is a high-sealing rotary valve.

13. The biomass gasification feeding system according to claim 1, characterized in that, The second feeding mechanism includes a conveying pipeline connecting the downstream sealing mechanism and the biomass gasifier, the conveying pipeline being inclined downwards from the sealing mechanism toward the biomass gasifier; The angle between the delivery pipeline and the horizontal plane is greater than or equal to 70°.

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