A biomass gasification system and method with dust removal function

Abstract

This invention relates to a biomass gasification system and method with dust removal function, including a gasifier, a burner, a raw material supply module, and a dust collection device. The raw material supply module is used to transport pulverized green waste or other biomass raw materials to the gasifier for gasification to generate biomass fuel gas. The inlet of the dust collection device is located near the outlet of the raw material supply module, and is used to extract dust entrained during the process of the raw material falling into the gasifier. The dust includes sawdust, glue fragments, and other lightweight combustible particles. The outlet of the dust collection device is connected to the oxygen supply path of the burner, and is used to introduce the dust into the burner to mix and burn with the biomass fuel gas. This invention, by constructing a closed-loop path of "dust extraction-reburning," can significantly reduce coking in the gasifier, improve gasification efficiency and burner temperature rise rate, achieve efficient recovery and utilization of dust energy, and enhance the overall operational stability and thermal output efficiency of the system.

Description

Technical Field

[0001] This invention relates to the field of biomass energy technology, and in particular to a biomass gasification system and method with dust removal function. Specifically, it refers to a biomass gasification and heat energy utilization system with dust adsorption and reburning function, which is suitable for efficient gasification and clean heat energy output of biomass resources such as garden green waste and forestry residues. Background Technology

[0002] Biomass energy is a clean and renewable energy source, widely derived from agricultural and forestry waste, urban greening branches, straw, and wood chips. Through gasification, it can be converted into combustible gases, providing a sustainable alternative for heat supply. Biomass gasification heating systems have significant environmental benefits and economic potential in industrial heating, district heating, and combined heat and power (CHP) applications.

[0003] Existing biomass gasification systems typically include: a feedstock pretreatment unit, a feeding system, a gasifier, a combustion device, a heat output unit, and a waste gas treatment unit. After being crushed, the biomass feedstock is continuously fed into the gasifier by a feeding system (such as a screw conveyor or belt conveyor), where it undergoes drying, pyrolysis, oxidation, and reduction reactions to generate a mixed combustible gas (mainly containing CO, H2, and CH4), which is then supplied to the burner for use in steam boilers, hot water boilers, or other thermal equipment.

[0004] However, in practical applications, biomass feedstocks often carry a large amount of lightweight dust, such as sawdust, colloid fragments, and fine fiber powder, during the crushing and transportation process. When this dust enters the gasifier along with the main feedstock, it can easily cause the following problems:

[0005] 1. Severe coking: Light dust easily softens and melts at high temperatures, accumulating on the gasifier wall or the lower part of the material bed to form coke blocks, which block the gasification channel;

[0006] 2. Gasification efficiency fluctuation: Coking will interfere with the airflow channel, resulting in uneven fuel distribution and disordered temperature zones, which in turn makes the gasification reaction rate and combustible gas composition unstable;

[0007] 3. Decreased operational reliability: Frequent coking necessitates periodic shutdowns for cleaning, shortening the system's operating cycle;

[0008] 4. Increased workload for manual maintenance: The descaling operation requires manual intervention, increasing labor costs;

[0009] 5. Insufficient combustion efficiency: The initial gas temperature of the burner is low, which may lead to ignition difficulties or a delayed thermal initial response.

[0010] Some improved gasification systems are equipped with dust collectors or cyclone separators at the gasifier outlet to purify combustible gases. However, these devices are often located at the end of the gas generation process, making it impossible to effectively control the dust material before it enters the furnace. This makes it impossible to fundamentally avoid the risk of coking and also fails to effectively utilize the energy value of the dust material.

[0011] Therefore, how to actively separate dust before the fuel enters the gasification reaction and efficiently recover it for combustion, without altering the original gasifier structure, has become a key technical issue for improving the operational efficiency and stability of biomass gasification heating systems. Summary of the Invention

[0012] This invention aims to address the problems in existing biomass gasification heating systems, such as dust easily entering the gasifier with the feedstock, causing coking, reducing gasification efficiency, and increasing the burden of operation and maintenance. It proposes an improved gasification heating system with a rational structure, clear path, and high energy recovery efficiency. By installing a dust collection device in the feedstock supply path, lightweight dust in the feedstock is actively separated before entering the gasifier and guided into the burner for co-combustion. This not only effectively reduces the coking frequency in the gasifier but also improves the combustion temperature rise rate and the system's thermal output efficiency, thereby achieving more efficient and cleaner utilization of biomass resources and improving the operational stability of the heating system.

[0013] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0014] A biomass gasification system with dust removal function, comprising:

[0015] A gasifier is used to gasify biomass feedstock to produce biomass fuel gas.

[0016] A burner for burning the biomass fuel gas to output heat energy;

[0017] The raw material supply module has its outlet connected to the feed inlet of the gasification furnace, and is used to transport the crushed green waste or other types of biomass raw materials to the gasification furnace.

[0018] The vacuuming device includes an air intake, a conveying channel, and connecting structures.

[0019] Its air intake is located in the outlet area of ​​the raw material supply module or near the feed inlet of the gasification furnace, and is used to suck up light combustible dust such as dust particles, wood fiber chips, and glue fragments carried in the raw material during the process of the raw material falling into the gasification furnace.

[0020] The dust collection device's conveying channel is connected to the burner's oxygen supply path, and is used to guide the dust material into the burner to burn together with the biomass fuel gas.

[0021] In this process, the dust is separated from the main gasification path of the raw materials and introduced into the burner for mixing and combustion.

[0022] This enables rapid high-temperature energy recovery from the dust material, reduces the risk of coking in the gasification furnace, improves the thermal stability of the gasification reaction, and extends the continuous operating time of the system.

[0023] Optionally, the dust collection device includes an air intake located in the outlet area of ​​the raw material supply module. The air intake has a constricted flow guide structure for collecting and preferentially extracting lightweight combustible dust.

[0024] Optionally, the dust collection device includes a dust conveying channel, which guides the dust to the oxygen supply channel of the burner through negative pressure or an auxiliary fan, so that the dust and biomass gas form a stable mixed airflow.

[0025] Optionally, the dust collection device is equipped with a filter screen or a vortex guide structure to block large particles, impurities or non-combustible materials that may be mixed in with the raw materials, so as to prevent clogging of the oxygen supply path of the burner.

[0026] Optionally, the working state of the dust collection device is linked to the operating state of the raw material supply module, and the suction is activated when the raw material is fed and automatically turned off after the raw material is stopped being fed.

[0027] Optionally, the connecting pipe between the dust collection device and the burner is made of heat-resistant and corrosion-resistant material, and is provided with a bend buffer section to reduce the impact of high-temperature gas backflow.

[0028] Optionally, the dust material includes, but is not limited to, wood chips, fiber fragments, adhesive microparticles, and other combustible lightweight particles. After being treated at high temperature inside the burner, the dust material can synergistically assist combustion with biomass gas, thereby improving the flame initiation temperature and combustion efficiency.

[0029] Optionally, the flue gas output from the burner is provided with a diversion path, which is connected to a dust removal device and a heat exchange module respectively, in order to realize pollution control and waste heat utilization of the flue gas from the steam boiler.

[0030] Optionally, the system further includes a soft water preparation module and a steam heating circuit for heating water using the heat energy output from the burner and supplying heat to the outside. The dust collection device constitutes an efficiency enhancement component of the entire thermal energy chain.

[0031] To achieve the above-mentioned technical objectives, the present invention also adopts the following technical solution:

[0032] A biomass gasification heating method with dust removal function, applied to any of the above-mentioned systems, comprising the following steps:

[0033] Step 1: The crushed green waste or other biomass raw materials are transported to the gasification furnace through the raw material supply module, and a dust collection device is installed at the discharge port and / or feeding section of the raw material supply module.

[0034] Step 2: During the process of the raw material falling into the gasification furnace, the dust suction device sucks up the dust entrained in the raw material;

[0035] Step 3: The dust material obtained by suction is introduced into the oxygen supply path of the burner through the conveying channel and mixed with the biomass gas generated during the gasification process of the raw materials;

[0036] Step 4: The mixed gas is ignited by the burner for high-temperature combustion, and steam or hot water is output for external use;

[0037] Step 5: During the combustion process, the dust material provides a rapid ignition heat source, increases the combustion initiation temperature, and inhibits coking in the gasification furnace, thereby improving the thermal efficiency and operational stability of the system.

[0038] The main advantages of the in-situ calibration device and method for level gauges of the present invention compared to the prior art are as follows:

[0039] This invention removes lightweight dust materials such as wood chips and glue fragments from the raw materials before they enter the gasifier by installing a dust collection device at the raw material feeding port. This prevents these dust particles from accumulating and melting in the gasification area, significantly reducing the frequency of coking and improving the continuity of system operation.

[0040] The dust material of this invention, being a finely broken combustible material, is prone to causing localized overheating and uneven heat distribution if it enters the gasifier. This invention addresses this by redirecting the dust material to the burner's recirculation path, thereby stabilizing the gasification reaction environment and improving the consistency and calorific value of the combustible gas.

[0041] In traditional gasification systems, dust is often treated as waste and sent to downstream dust removal equipment along with the gas, failing to fully release its energy. This invention reintroduces the dust into the high-temperature zone of the burner for mixing and combustion, fully releasing its calorific value, achieving an "energy closed loop," and improving the overall energy efficiency of the system.

[0042] The dust material of this invention has the characteristics of low heat capacity and easy ignition. After entering the burner as auxiliary fuel, it can quickly participate in the initial combustion, playing a role in combustion assistance and heat guidance, thus solving the problems of slow burner temperature and unstable initial flame in existing systems.

[0043] The system of this invention can significantly extend continuous operation time and reduce the number of shutdowns due to frequent furnace cleaning caused by coking by reducing coking. This helps to reduce manual maintenance costs and improve the overall economic efficiency and industrial adaptability of the system. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the overall structure of the biomass gasification system of the present invention;

[0045] Figure 2 This is a schematic diagram illustrating the steps of the biomass gasification heating method of the present invention. Detailed Implementation

[0046] The following provides further details on specific embodiments of the present invention:

[0047] Firstly, given the increasing demand for clean energy, the efficient utilization of biomass energy, as a clean and renewable energy source, is crucial. This invention, a biomass gasification system and method with dust removal function, aims to solve many problems existing in current biomass gasification heating systems, achieving more efficient and cleaner utilization of biomass resources and improving the operational stability of the heating system. The specific implementation methods will be described in detail below.

[0048] like Figure 1 As shown, the detailed implementation methods of each module of the biomass gasification system with dust removal function in this embodiment are described below:

[0049] Gasification furnace:

[0050] The gasifier is the core equipment in the entire system for the gasification reaction of biomass feedstock. Its internal structure design must meet the condition requirements of the biomass feedstock at different reaction stages. For example, a fixed-bed gasifier structure can be adopted, which has advantages such as good gas-solid contact and stable reaction.

[0051] In actual operation, biomass feedstock enters the gasification furnace from the top and undergoes four reaction stages from top to bottom: drying, pyrolysis, oxidation, and reduction.

[0052] Drying Stage: After the biomass briquettes enter the gasification furnace, they are first heated to remove surface moisture. The temperature range for this stage is approximately 100-150℃, with most of the moisture released below 105℃. To achieve efficient drying, the gasification furnace can be equipped with heating devices, such as electric heating wires or gas heating pipes, to provide a stable heat source. Simultaneously, vents are installed at the top of the gasification furnace to expel the large amount of water vapor generated during the drying process, ensuring smooth operation. For example, for a batch of green waste raw materials with a moisture content of 20%, by controlling the heating temperature and ventilation during the drying stage, the moisture content can be reduced to below 10% in approximately 15-20 minutes.

[0053] Pyrolysis Stage: After preliminary drying, the biomass feedstock begins initial pyrolysis and gasification at a temperature of 400-600℃, releasing volatile components, including hydrocarbons, hydrogen, tar, water vapor, carbon monoxide, and carbon dioxide. To promote the pyrolysis reaction, a stirring device can be installed in the gasification furnace to ensure more uniform heating of the feedstock. For example, the stirring device can be activated every 5 minutes for 30 seconds each time to ensure sufficient reaction of the feedstock during the pyrolysis stage. Simultaneously, a temperature sensor monitors the furnace temperature in real time, automatically adjusting the heating power when the temperature deviates from the set range to ensure the pyrolysis reaction proceeds at a suitable temperature.

[0054] Oxidation Stage: The pyrolysis products undergo an oxidation reaction with a limited amount of air or oxygen within the gasifier. This is a vigorous exothermic reaction. In the oxidation zone of a fixed-bed gasifier, the heat released by combustion can raise the temperature to 1000-1400℃. To precisely control the oxidation reaction, the supply of air or oxygen needs to be accurately controlled. For example, a flow control valve can be used to adjust the air or oxygen flow rate in real time based on monitoring data of the furnace temperature and gas composition. This ensures that the oxidation reaction provides sufficient heat to sustain subsequent reactions without reducing gasification efficiency due to over-combustion.

[0055] Reduction Stage: Located after the oxidation reaction, the reduction reaction involves the reaction of water vapor and CO2 produced by combustion with coke to generate H2 and CO. To increase hydrogen production and promote the water-gas reaction, water vapor (softened water) needs to be added to the gasifier. Softened water can be evenly sprayed into the reduction zone through steam nozzles to ensure sufficient contact and reaction with the coke. Simultaneously, the reduction reaction is endothermic; as the reaction proceeds, the temperature continuously decreases, and the reaction rate gradually slows down. Therefore, a heating device is also required in the reduction zone to maintain a suitable reaction temperature, approximately 600-900℃.

[0056] In addition, to handle the small amount of tar water (approximately 5% volatile matter) generated during the initial gasification process, the gasifier is equipped with a purification device. This device collects the tar water and returns it to the fuel bed inside the furnace for secondary gasification and pyrolysis, ultimately converting it entirely into gaseous fuel without producing residual wood tar. Simultaneously, the gasifier employs a rotating bottom wet slag removal process, utilizing water (softened water) stored in the ash pan to seal the inside and outside of the furnace. The water in the ash pan is absorbed by the slag, and water is replenished as needed based on the water level drop to ensure furnace sealing and prevent dust generation. Most of the water in the ash pan is lost as steam, with a small portion absorbed by the slag and entering solid waste, resulting in no wastewater generation. After discharge, the slag is directly bagged for temporary storage, eliminating the need for washing the workshop floor.

[0057] Burner:

[0058] The burner is used to combust the biomass gas generated by the gasification furnace and the dust conveyed by the dust collection device to output heat energy. The burner design must ensure that the biomass gas and dust can be fully mixed and combusted stably.

[0059] The burner can employ a premixed combustion structure, meaning that biomass fuel gas and dust are thoroughly mixed with air in a mixing chamber before combustion. Baffles are installed inside the mixing chamber to increase the turbulence of the gas and dust, resulting in more uniform mixing. For example, the shape and angle of the baffles are carefully designed to create a complex flow field within the mixing chamber, ensuring thorough mixing of the three components.

[0060] During combustion, the flame status is monitored in real time by a flame detector. When the flame becomes unstable or extinguishes, the flame detector sends a signal to the control system, which immediately cuts off the gas supply and restarts the ignition device. Simultaneously, the burner is equipped with a temperature sensor to monitor the combustion temperature in real time. By adjusting the gas and air supply, the combustion temperature is maintained within a set range to improve combustion efficiency and thermal output stability. For example, for biomass gas with CO and H2 as its main components, controlling the combustion temperature between 1200-1400℃ achieves highly efficient combustion.

[0061] In addition, the flue gas output from the burner has a branch path, connecting to a dust removal device and a heat exchange module respectively. The path connected to the dust removal device is used to remove pollutants such as particulate matter and sulfides from the flue gas, ensuring that emissions meet environmental standards; the path connected to the heat exchange module is used to utilize the waste heat of the steam boiler flue gas, improving energy efficiency. For example, a bag filter is used in the dust removal device to effectively remove fine particulate matter from the flue gas; in the heat exchange module, heat from the flue gas is transferred to cold water through a heat exchanger to produce hot water or steam for heating other process or domestic water.

[0062] Raw material supply module:

[0063] The raw material supply module is responsible for conveying the pulverized green waste or other types of biomass raw materials to the gasification furnace. This module typically includes a storage bin, conveying equipment, and control devices.

[0064] Storage silos are used to store pulverized biomass raw materials, and their design must consider factors such as storage capacity, moisture protection, and ventilation. For example, storage silos can adopt a sealed structure with internal ventilation openings and humidity sensors. When the humidity exceeds a set value, the ventilation equipment is automatically activated to prevent the raw materials from becoming damp and deteriorating. Simultaneously, the capacity of the storage silos is rationally designed based on the system's processing capacity and the raw material supply to ensure a continuous supply of raw materials.

[0065] Conveying equipment can be either screw conveyors or belt conveyors. Screw conveyors offer good sealing and high conveying efficiency, making them suitable for conveying powdery or small-particle biomass raw materials. Belt conveyors are suitable for conveying larger particles or lumps of raw materials over longer distances. For example, screw conveyors can be used to transport pulverized wood chips, while belt conveyors can be used for larger-sized biomass briquettes. The conveying speed can be adjusted using a frequency converter to precisely control the amount of raw material conveyed according to the feeding requirements of the gasifier.

[0066] The control device coordinates the operation of the storage bins and conveying equipment. For example, when the raw material in the storage bins falls below a certain level, the control device sends a signal to the feeding equipment to replenish the raw material; when the raw material sensor at the gasifier inlet detects insufficient raw material, the control device automatically increases the conveying speed of the conveying equipment to ensure continuous feeding of the gasifier.

[0067] Vacuum cleaning device:

[0068] The dust extraction device is a key part of this invention. Its purpose is to effectively extract the dust entrained in the raw materials before they enter the gasification furnace and guide it to the burner to be burned together with the biomass gas.

[0069] Air intake: The air intake is located in the outlet area of ​​the raw material supply module or near the inlet of the gasification furnace. To more effectively gather and preferentially extract lightweight combustible dust, the air intake adopts a tapered airflow guide structure. This structure concentrates the airflow generated during the raw material's descent, guiding the lightweight dust towards the air intake. For example, the tapering angle of the air intake can be designed from 30° to 60°, adjusted according to the actual raw material's descent speed and the characteristics of the dust, ensuring maximum dust extraction. Simultaneously, the air intake can be equipped with multiple adjustable guide vanes to further optimize the airflow direction and improve dust extraction efficiency.

[0070] Conveying Channel: The dust collection device guides the sucked-up dust to the oxygen supply channel of the burner through a dust conveying channel. To ensure smooth dust conveying, the channel can be operated using negative pressure or an auxiliary fan. When using negative pressure, a vacuum pump is installed at the end of the channel to create a negative pressure environment, drawing in the dust and conveying it to the burner. If an auxiliary fan is used, a fan is installed at an appropriate location in the channel, using positive pressure to blow the dust to the burner. For example, for longer conveying channels, a multi-stage fan relay system can be used to ensure that the dust does not become clogged due to excessive resistance during transport. Furthermore, to ensure a stable mixture of dust and biomass fuel gas, a mixer, such as a Venturi mixer, can be installed at the connection between the burner's oxygen supply channel and the conveying channel, utilizing the Venturi effect to thoroughly mix the dust and fuel gas.

[0071] Filtration and Protection Structure: The dust collection device is equipped with a filter screen or a cyclone guide structure to block large particles, impurities, or non-combustible materials that may be mixed in with the raw materials, preventing them from clogging the oxygen supply path of the burner. The filter screen can be made of stainless steel, with an appropriate mesh size selected according to actual needs. For example, a mesh size of 1-5mm can effectively block large particles without affecting the passage of dust. The cyclone guide structure separates large particles by causing the airflow to rotate and using centrifugal force. For example, spiral blades are installed in the channel, causing the airflow to form a spiral motion. Large particles are thrown against the channel wall under centrifugal force, thus achieving separation from the dust.

[0072] Operation Control: The operating status of the dust collection device is linked to the operating status of the raw material supply module. When the raw material supply module starts feeding, the control system detects the operating signal of the conveyor equipment and automatically activates the suction function of the dust collection device. When the raw material feeding stops, the control system detects the stop signal of the conveyor equipment and, after a certain delay (e.g., 1-2 minutes to ensure that residual dust is completely removed), automatically shuts off the suction function. This linked control method not only effectively removes dust but also avoids ineffective operation of the dust collection device, saving energy.

[0073] Connecting Duct: The connecting duct between the vacuum cleaner and the burner is made of heat- and corrosion-resistant materials, such as stainless steel or ceramic composites, to withstand high-temperature, high-humidity environments and the presence of potentially corrosive gases. Simultaneously, to mitigate the impact of high-temperature gas backflow, the connecting duct is equipped with a bend buffer section. The bending angle and length of the bend buffer section are designed according to actual conditions; for example, the bending angle can be set to 90°-180°, and the length to be 1-2 meters. By changing the airflow direction and increasing the airflow path length, the impact of high-temperature gas is effectively buffered, protecting the vacuum cleaner and related equipment.

[0074] Detailed implementation of the system operation flow in this embodiment

[0075] 1. Raw material preparation and transportation

[0076] First, biomass raw materials such as green waste and forestry residues are crushed to a particle size suitable for gasification. For example, branches and straw are crushed into particles with a diameter of about 5-10 mm using a crusher. The crushed raw materials are then temporarily stored in the storage bin of the raw material supply module.

[0077] When the system starts, the conveying equipment of the raw material supply module begins to operate, transporting the raw materials in the storage bin to the feed inlet of the gasification furnace. The conveying speed of the equipment is adjusted according to the feeding requirements of the gasification furnace to ensure that the raw materials can enter the gasification furnace evenly and stably. During the conveying process, the dust collection device is linked to the raw material supply module. When the conveying equipment starts, the suction port of the dust collection device begins to operate, sucking up the dust and dirt carried by the raw materials during their descent.

[0078] 2. Dust suction and conveying

[0079] The dust collection device's suction port utilizes its constricted airflow structure to effectively gather and extract lightweight combustible dust materials, such as sawdust, fiber fragments, and viscous particles, as the raw materials fall into the gasification furnace. The suction power of the suction port can be adjusted according to actual conditions. For example, by adjusting the fan speed or negative pressure value, the air velocity at the suction port can be maintained at 5-10 m / s to ensure that sufficient dust materials are extracted.

[0080] The extracted dust is guided through a conveying channel to the oxygen supply channel of the burner under negative pressure or by an auxiliary fan. During the conveying process, a filter screen or cyclone guide structure filters and separates the dust, preventing large particles, impurities, or non-combustible materials from entering the burner. Simultaneously, pressure and flow sensors installed on the conveying channel monitor the conveying pressure and flow rate of the dust in real time to ensure stable conveying. If abnormal pressure or low flow occurs, the control system will issue an alarm and take corresponding measures, such as cleaning the filter screen or checking the fan's operating status.

[0081] 3. Gasification reaction

[0082] Biomass feedstock undergoes four reaction stages in sequence—drying, pyrolysis, oxidation, and reduction—in a gasifier to generate biomass fuel gas.

[0083] Drying Stage: As mentioned earlier, the furnace temperature is raised to 100-150℃ using a heating device, causing the moisture in the raw materials to gradually evaporate. The power of the heating device is automatically adjusted according to the moisture content of the raw materials and the feed rate to ensure the drying effect. Simultaneously, water vapor is promptly discharged through ventilation openings to maintain a dry environment inside the furnace.

[0084] Pyrolysis stage: The dried raw materials undergo pyrolysis at a temperature of 400-600℃. A stirring device and temperature control device ensure that the raw materials react fully during the pyrolysis stage, releasing volatile components. The stirring frequency and intensity can be adjusted according to the characteristics of the raw materials. For example, for harder raw materials, the stirring frequency and intensity can be appropriately increased to ensure more uniform heating.

[0085] Oxidation stage: The pyrolysis products undergo an oxidation reaction with limited air or oxygen at a high temperature of 1000-1400℃, releasing a large amount of heat. The stable progress of the oxidation reaction is ensured by precisely controlling the supply of air or oxygen. Simultaneously, a temperature sensor monitors the temperature of the oxidation zone in real time; when the temperature is too high, the air or oxygen supply is appropriately reduced; when the temperature is too low, the supply is increased to maintain a suitable reaction temperature.

[0086] Reduction Stage: In the reduction zone, by supplementing with steam and using a heating device, the steam and CO2 produced by combustion react with the coke to generate H2 and CO. The amount of steam supplied is adjusted according to the reaction requirements, and the heating device ensures that the reduction reaction takes place within a temperature range of 600-900℃. Precise control of the reduction stage improves the quality and yield of biomass fuel gas.

[0087] 4. Hybrid Combustion and Heat Output

[0088] Biomass fuel gas from the gasifier is mixed with dust transported by a dust collection device and then combusted in the burner after being thoroughly mixed with air. The burner's premixing structure and mixer ensure uniform mixing of fuel gas, dust, and air. During combustion, a flame detector monitors the flame status in real time, a temperature sensor monitors the combustion temperature, and the control system automatically adjusts the supply of fuel gas, air, and dust based on the monitoring data to ensure stable combustion, high efficiency, and stable heat output.

[0089] The heat generated by combustion is used to heat soft water to produce steam or hot water, which is then supplied to the outside through a steam heating loop. For example, in a steam boiler, the high-temperature flue gas produced by combustion transfers heat to the soft water through a heat exchanger, raising the water temperature and converting it into steam. After being distributed by a steam distributor, the steam is transported to the heat-using unit through pipelines, where it undergoes indirect heat exchange with the unit's cold water, cold air, etc., to achieve heating. Simultaneously, the condensate after heat exchange is returned to the boiler through pipelines for recycling, improving energy efficiency.

[0090] 5. System monitoring and maintenance

[0091] The entire system is equipped with a comprehensive monitoring system, including temperature sensors, pressure sensors, flow sensors, flame detectors, etc., to monitor the operating parameters of each part of the system in real time. The monitoring system transmits the collected data to the control system, which analyzes and processes the data. When abnormal parameters are detected, the control system promptly issues an alarm and takes corresponding control measures, such as adjusting equipment operating parameters and activating backup equipment, to ensure the safe and stable operation of the system.

[0092] In addition, regular system maintenance and upkeep are essential, including checking equipment operation, cleaning filters, and replacing worn parts. For example, the dust collection device's filter should be cleaned or replaced every month to ensure effective dust collection; the internal structure of the gasification furnace should be inspected every three months to check for coking, wear, or other issues, and addressed promptly to extend the equipment's lifespan.

[0093] like Figure 2 As shown in the figure, the detailed implementation steps of the heating method of the biomass gasification system with dust removal function in this embodiment are as follows:

[0094] Step 1: Setting up raw material conveying and dust collection devices

[0095] The crushed green waste or other biomass raw materials are transported from the storage silo to the gasification furnace feed inlet via the conveying equipment of the raw material supply module. A dust collection device is installed at the discharge port and / or feed section of the raw material supply module to ensure effective extraction of entrained dust during the material's descent. For example, for a screw conveyor, a suction port for the dust collection device can be installed below its discharge port, ensuring close alignment with the material's descent path to improve dust collection efficiency.

[0096] Step 2: Dust extraction

[0097] As the raw materials fall into the gasification furnace, the dust extraction device's suction port begins operation, utilizing its constricted airflow structure and appropriate suction force to extract dust entrained in the raw materials. The suction force of the suction port can be adjusted according to the characteristics of the raw materials and the dust content. For example, for raw materials with a high dust content, the suction force is appropriately increased; for lightweight raw materials, the suction force is appropriately decreased to avoid extracting too much material. Simultaneously, by adjusting the angle of the guide vane at the suction port, the airflow direction is optimized to ensure maximum dust extraction.

[0098] Step 3: Dust Material Introduction and Mixing

[0099] The extracted dust is conveyed through a transport channel and, under negative pressure or with an auxiliary fan, is introduced into the oxygen supply path of the burner. During this process, a mixer ensures that the dust is thoroughly mixed with the biomass fuel gas generated during the gasification of the raw materials. The structure and parameters of the mixer are designed according to actual conditions. For example, the throat diameter and length of the Venturi mixer need to be optimized based on factors such as the flow rate and velocity of the fuel gas and dust to ensure uniform mixing and a stable mixed airflow.

[0100] Step 4: High-temperature combustion and heating

[0101] The mixed gas is ignited by a burner for high-temperature combustion. The burner's ignition device employs either electronic or gas ignition to ensure reliable ignition. During combustion, flame detectors and temperature sensors monitor the flame state and combustion temperature in real time. The control system automatically adjusts the supply of gas, air, and dust based on the monitoring data, ensuring stable combustion and improving combustion efficiency. The heat generated by combustion is used to heat soft water, producing steam or hot water, which is then supplied to the outside through a steam heating circuit. For example, in a steam boiler, the high-temperature flue gas generated by combustion transfers heat to soft water through a heat exchanger, converting the soft water into steam. The steam is then piped to the heat-consuming unit to provide heating.

[0102] Step 5: System Optimization and Stable Operation

[0103] During combustion, the dust, with its low heat capacity and easy ignition, provides a rapid ignition heat source, increasing the initial combustion temperature and making combustion more stable. Simultaneously, because the dust is separated from the main gasification path of the raw materials, it avoids agglomeration and melting within the gasifier, inhibiting coking and thus improving the system's thermal efficiency and operational stability. Furthermore, by continuously monitoring and analyzing system operating parameters in real time, the system's operating status is optimized, such as adjusting the raw material conveying speed, the suction power of the dust collector, and the gas-air ratio of the burner, ensuring long-term stable and efficient operation. For example, based on monitoring data of combustion temperature and flue gas composition, the supply of gas and air is adjusted in a timely manner to ensure more complete combustion and improve thermal energy output efficiency; based on monitoring of temperature distribution and coking conditions within the gasifier, the operating parameters of the dust collector are adjusted to further reduce coking.

[0104] Meanwhile, the system is regularly inspected and maintained, including checking for coking inside the gasifier, cleaning the dust collection device filter, and cleaning the burner nozzles. Any problems found are dealt with promptly, such as cleaning coking material inside the gasifier, replacing clogged filters, and adjusting the position of the burner nozzles, to ensure the normal operation of all system components and extend the system's service life.

[0105] During long-term operation, the system can be upgraded and improved according to changes in actual heating demand and raw material characteristics. For example, if heating demand increases, the size of the gasifier and burner can be appropriately increased to improve the system's capacity; if the type or characteristics of the raw materials change, the structure of the dust collection device's air inlet, the parameters of the conveying channel, and the combustion parameters of the burner can be adjusted accordingly to adapt to the new raw material conditions and ensure that the system always maintains a good operating condition.

[0106] Through the detailed embodiments described above, the biomass gasification system and method with dust removal function of the present invention can effectively solve the problems existing in the current biomass gasification heating system, realize the efficient utilization of biomass resources and the stable operation of the heating system, and provide a reliable technical solution for the development and application of biomass energy. In practical applications, the various parts of the system can be flexibly configured and adjusted according to different needs and conditions to meet diverse production and heating needs, and has broad application prospects and significant economic and environmental benefits.

[0107] Furthermore, with continuous technological development and advancement, intelligent control technology and big data analytics can be incorporated into the system. Intelligent control technology enables automated operation and intelligent adjustment of the system, automatically optimizing system parameters based on real-time monitoring data to improve system efficiency and stability. Big data analytics, on the other hand, analyzes data accumulated over long-term system operation, uncovering potential optimization opportunities, predicting equipment failures, and enabling proactive maintenance and upkeep, further reducing system operating costs and improving reliability.

[0108] For example, by utilizing intelligent control technology, the system can automatically adjust the raw material conveying speed, burner combustion power, and dust collection device operating status based on factors such as outdoor temperature and heating demand, achieving precise energy supply and efficient utilization. Through big data analysis, in-depth research can be conducted on the gasification characteristics, coking conditions, and relationships between system operating parameters of different types of biomass raw materials, providing a more scientific basis for system optimization. Simultaneously, equipment fault early warning models can be established to predict potential faults based on trends in equipment operating parameters, promptly notifying maintenance personnel to handle them and avoiding downtime and production losses due to equipment failure.

[0109] The biomass gasification system and method with dust removal function of the present invention not only has important practical value at present, but also has the potential for further optimization and improvement in the future with the continuous development of related technologies, which will make a greater contribution to the development of the biomass energy field.

[0110] In summary, by installing a dust collection device at the raw material feeding port, the present invention removes lightweight dust materials such as wood chips and glue fragments from the raw materials before they enter the gasifier, thereby preventing these dust particles from accumulating and melting in the gasification area, significantly reducing the frequency of coking, and improving the continuity of system operation.

[0111] The dust material of this invention, being a finely broken combustible material, is prone to causing localized overheating and uneven heat distribution if it enters the gasifier. This invention addresses this by redirecting the dust material to the burner's recirculation path, thereby stabilizing the gasification reaction environment and improving the consistency and calorific value of the combustible gas.

[0112] In traditional gasification systems, dust is often treated as waste and sent to downstream dust removal equipment along with the gas, failing to fully release its energy. This invention reintroduces the dust into the high-temperature zone of the burner for mixing and combustion, fully releasing its calorific value, achieving an "energy closed loop," and improving the overall energy efficiency of the system.

[0113] The dust material of this invention has the characteristics of low heat capacity and easy ignition. After entering the burner as auxiliary fuel, it can quickly participate in the initial combustion, playing a role in combustion assistance and heat guidance, thus solving the problems of slow burner temperature and unstable initial flame in existing systems.

[0114] The system of this invention can significantly extend continuous operation time and reduce the number of shutdowns due to frequent furnace cleaning caused by coking by reducing coking. This helps to reduce manual maintenance costs and improve the overall economic efficiency and industrial adaptability of the system.

[0115] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A biomass gasification system with dust removal function, characterized in that, include: A gasifier is used to gasify biomass feedstock to produce biomass fuel gas. A burner for burning the biomass fuel gas to output heat energy; The raw material supply module has its outlet connected to the feed inlet of the gasification furnace, and is used to transport the crushed green waste biomass raw material to the gasification furnace. The vacuuming device includes an air intake, a conveying channel, and connecting structures. Its air intake is located in the outlet area of ​​the raw material supply module or near the feed inlet of the gasification furnace, and is used to extract dust particles, wood fiber chips, glue fragments and lightweight combustible dust entrained in the raw material during the process of the raw material falling into the gasification furnace. The dust collection device's conveying channel is connected to the burner's oxygen supply path, and is used to guide the dust material into the burner to burn together with the biomass fuel gas. In this process, the dust is separated from the main gasification path of the raw materials and introduced into the burner for mixing and combustion. The dust collection device includes an air intake located in the outlet area of ​​the raw material supply module. The air intake has a tapered airflow guiding structure for collecting and preferentially extracting lightweight combustible dust. The dust collection device includes a dust conveying channel, which guides the dust to the oxygen supply channel of the burner through negative pressure or an auxiliary fan, so that the dust and biomass fuel gas form a stable mixed airflow. The dust collection device is equipped with a filter screen or a swirling guide structure to block large particles, impurities, or non-combustible materials that may be mixed in with the raw materials, thereby preventing blockage of the oxygen supply path to the burner. The working status of the dust collection device is linked to the operating status of the raw material supply module. The suction is activated when the raw material is fed and automatically turned off when the raw material stops being fed.

2. The system of claim 1, wherein, The connecting pipe between the dust collection device and the burner is made of heat-resistant and corrosion-resistant material, and is equipped with a bend buffer section to reduce the impact of high-temperature gas backflow.

3. The system of claim 2, wherein, The dust material includes wood chips, fiber fragments, adhesive microparticles, and other combustible lightweight particles. After being treated at high temperature in the burner, the dust material can synergistically assist combustion with biomass gas, thereby improving the flame initiation temperature and combustion efficiency.

4. The system according to claim 3, characterized in that, The flue gas output from the burner is provided with a diversion path, which is connected to a dust removal device and a heat exchange module respectively, in order to realize pollution control and waste heat utilization of the flue gas from the steam boiler.

5. The system according to claim 4, characterized in that, The system also includes a soft water preparation module and a steam heating circuit, which are used to heat water using the heat energy output from the burner and supply heat to the outside. The dust collection device constitutes an efficiency enhancement component of the entire thermal energy chain.

6. A biomass gasification heating method with dust removal function, applied to the system described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: The crushed green waste biomass raw material is transported to the gasification furnace through the raw material supply module, and a dust collection device is installed at the discharge port and / or feeding section of the raw material supply module. Step 2: During the process of the raw material falling into the gasification furnace, the dust suction device sucks up the dust entrained in the raw material; Step 3: The dust material obtained by suction is introduced into the oxygen supply path of the burner through the conveying channel and mixed with the biomass gas generated during the gasification process of the raw materials; Step 4: The mixed gas is ignited by the burner for high-temperature combustion, and steam or hot water is output for external use; Step 5: During the combustion process, the dust material provides a rapid ignition heat source, increases the combustion initiation temperature, and inhibits coking in the gasification furnace, thereby improving the thermal efficiency and operational stability of the system.

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