Mixed suction type biomass fixed bed gasifier system and use method

Abstract

The invention discloses a mixed suction type biomass fixed bed gasifier system and a using method, and relates to the technical field of biomass gasification equipment, the mixed suction type biomass fixed bed gasifier system comprises a feeding mechanism, a first gasifier body, a second gasifier body, a tower-shaped grate, an ash tray and a rotating base, the first gasifier body is provided with a drying layer, a pyrolysis layer, a first oxidation layer and a first reduction layer, and the second gasifier body is provided with a second oxidation layer and a second reduction layer; the first oxidation layer enables residual fixed carbon and fuel gas after pyrolysis to be subjected to oxidation reaction with oxygen and generate first heat, and the first heat can enable tar to be subjected to cracking reaction; the second gasification furnace body comprises an annular fuel gas channel, a second reduction layer, a second oxidation layer and an ash layer, the annular fuel gas channel is formed in the space between the first gasification furnace body and the second gasification furnace body, and the annular fuel gas channel is used for reducing the flow speed of combustible gas and is communicated with the combustible gas collecting device. The utilization efficiency of biomass energy is effectively improved, the tar content of fuel gas is effectively reduced, and the dust content of the fuel gas is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass gasification equipment, and in particular to a mixed-suction biomass fixed-bed gasification furnace system and a use method thereof. Background Art

[0002] Against the backdrop of the increasing diversification of the global energy mix and the growing demand for clean energy, biomass energy, as a rich, renewable source of clean energy, has garnered widespread attention and research. Biomass gasification technology, as a key means of converting biomass into high-quality energy, plays a vital role in achieving efficient biomass utilization. Updraft and downdraft fixed-bed gasifiers are two of the most widely used traditional biomass gasification furnace types. However, these technologies have faced a series of significant challenges in their long-term practical application, severely hindering the further development and expansion of biomass gasification technology.

[0003] Limitations of Updraft Fixed-Bed Gasifiers

[0004] Gasification efficiency: Updraft fixed-bed gasifiers consistently struggle to break the 75% upper limit. This means that only a portion of the biomass input is converted into usable fuel gas, while the remaining energy is wasted in the form of incompletely reacted substances or other waste, resulting in low energy utilization. This not only fails to fully unleash the energy contained in the biomass, but also results in unnecessary resource loss and increased energy production costs.

[0005] Gas quality problem: The tar content in the gas produced by this type of furnace is generally 50-100g / m 3 Tar is sticky and easily adheres to gas pipelines, equipment components, and purification devices, causing pipeline blockage, reducing the service life of equipment, and increasing maintenance costs. In addition, tar may also cause incomplete combustion during the combustion process, further polluting the environment and failing to meet the needs of high-end application scenarios such as chemical synthesis and precision instrument heating, which have extremely strict requirements on gas cleanliness. At the same time, the calorific value of the gas generated by the updraft fixed-bed gasifier is only ≥1100kcal / m 3 , the combustion temperature is maintained at around 1200°C. In industrial production processes that require high-temperature heat sources (such as certain metallurgical processes and high-temperature kilns), the low calorific value of fuel and the combustion temperature cannot meet the activation energy and thermal environment requirements required for the reaction, which greatly limits the application of this technology in these fields.

[0006] Disadvantages of Downdraft Fixed Bed Gasifier

[0007] Gasification efficiency bottleneck: Similar to updraft gasifiers, downdraft fixed-bed gasifiers achieve a maximum gasification efficiency of only 75%, failing to meet the expectations of large-scale, efficient energy production. This efficiency limitation poses challenges to the economic benefits and energy supply stability of large-scale biomass gasification projects, making it difficult to establish strong competitiveness in the energy market.

[0008] Gas purity challenge: The dust content in the gas produced by the downdraft fixed-bed gasifier is about 50g / m 3 , high dust content will cause serious wear and tear on subsequent gas processing and utilization equipment, affecting the normal operation and service life of the equipment. In addition, in order to reduce the negative impact of dust on the system, complex and expensive dust removal equipment must be additionally configured. This not only increases the construction cost and operating burden of the entire gasification system, but also reduces the stability and efficiency of the system operation. For those application environments that are sensitive to dust (such as electronics manufacturing, food processing and other industries), the dusty gas produced by the downdraft gasifier cannot meet their production process requirements at all; furthermore, the low calorific value and combustion temperature of the gas make it difficult for this type of furnace to meet the needs of high-temperature industrial production and certain special energy applications, limiting its scope of application.

[0009] In summary, the various problems exposed in the actual application of traditional updraft and downdraft fixed-bed gasifiers have seriously hindered the efficient, clean and widespread application of biomass gasification technology.

[0010] The development of a new mixed-suction biomass fixed-bed gasifier that combines the advantages of both technologies while effectively overcoming their respective shortcomings has become an urgent need for industry development. This new type of gasifier will open up new avenues for the efficient utilization of biomass energy, strongly promoting the large-scale application of biomass energy in multiple fields, and further promoting the optimization of energy structure and sustainable development. Summary of the Invention

[0011] The purpose of the present invention is to provide a mixed-suction biomass fixed-bed gasification furnace system and a method of use to solve the problems existing in the above-mentioned prior art. It has a simple structure, is easy to use, effectively improves the utilization efficiency of biomass energy, effectively reduces the tar content of the fuel gas, and effectively reduces the dust content of the fuel gas.

[0012] To achieve the above object, the present invention provides the following solutions:

[0013] The present invention provides a mixed-suction biomass fixed-bed gasification furnace system, comprising: a feeding mechanism, a first gasification furnace body, a second gasification furnace body, a tower-shaped grate, an ash tray and a rotating base, wherein the feeding mechanism is used to convey biomass raw materials; a feeding port is provided on the top of the first gasification furnace body, and the feeding mechanism conveys the biomass raw materials into the first gasification furnace body through the feeding port; a drying layer, a pyrolysis layer, a first oxidation layer and a first reduction layer are sequentially provided in the first gasification furnace body from top to bottom, the drying layer is used to dry the biomass raw materials and reduce the humidity of the biomass raw materials to a level where a pyrolysis reaction occurs, and the pyrolysis layer is used to provide a high-temperature environment to The biomass raw material is pyrolyzed into fuel gas, tar and residual fixed carbon. The first oxidation layer is used to provide oxygen supply and high temperature environment so that the residual fixed carbon and the fuel gas undergo oxidation reaction with oxygen and generate first heat. The first heat provides energy support for the drying layer, the pyrolysis layer and the first reduction layer, and can also cause the tar to undergo cracking reaction. The first reduction layer is used to provide a reducing atmosphere to reduce the remaining substances after the high-temperature oxidation reaction of the first oxidation layer and generate combustible gas and coke. The second gasification furnace body includes an annular fuel gas channel, a second reduction layer, a second oxidation layer and ash arranged in sequence from top to bottom. The bottom of the first gasification furnace body extends into the top of the second gasification furnace body and is sealed and connected to the second gasification furnace body. The space between the first gasification furnace body and the second gasification furnace body forms the annular gas channel. The top of the annular gas channel is connected to the combustible gas collecting device so that the combustible gas enters the combustible gas collecting device after passing through the annular gas channel. The second reduction layer is used to cause the coke to undergo a reduction reaction to generate combustible gas. The second oxidation layer is used to provide oxygen and a high-temperature environment to fully burn the carbon in the remaining coke and generate a second heat and carbon dioxide. The second heat is used to maintain the second oxidation layer. The high-temperature environment provides energy for the second reduction reaction layer, and the carbon dioxide rises to the second reduction layer to participate in the reduction reaction as a reactant of the reduction reaction. The ash layer is used to collect the residue produced by the second oxidation reaction layer; the tower-type grate is arranged below the second gasification furnace body, and its top extends into the ash layer to allow air to pass into the ash layer; the ash pan is arranged below the second gasification furnace body and forms an ash removal channel with the second gasification furnace body, and the bottom of the tower-type grate is fixedly connected to the ash pan; the bottom of the rotating base is fixedly connected to the ground, and the driving end of the rotating base is fixedly connected to the ash pan to drive the ash pan to rotate.

[0014] Preferably, it further includes a first water-cooling jacket, a first circulating water supply device, a second water-cooling jacket and a second circulating water supply device, the first water-cooling jacket is arranged on the outside of the portion of the first gasification furnace body extending out of the second gasification furnace body, the first water-cooling jacket is connected to the first circulating water supply device, the second water-cooling jacket is arranged on the outside of the second gasification furnace body, and the second water-cooling jacket is connected to the second circulating water supply device.

[0015] Preferably, the feeding mechanism is a screw feeder.

[0016] Preferably, it also includes a first air supply system, a first annular air supply pipe and multiple first air supply branches, the first gasification furnace body is provided with multiple first ignition holes and multiple first air inlet holes, the first ignition holes correspond to the bottom position of the first oxidation layer, the first air inlet holes correspond to the middle position of the first oxidation layer, the first annular air supply pipe is sleeved on the outside of the first gasification furnace body, and is connected to the output end of the first air supply system, one end of the first air supply branch is connected to the first annular air supply pipe, and the other end is connected to the first air inlet hole.

[0017] Preferably, it also includes a second air supply system, a second annular air supply pipe and multiple second air supply branches. The second gasification furnace body is provided with multiple second ignition holes and multiple second air inlet holes. The second ignition holes correspond to the bottom position of the second oxide layer, and the second air inlet holes correspond to the middle position of the second oxide layer. The second annular air supply pipe is sleeved on the outside of the second gasification furnace body and is connected to the output end of the second air supply system. One end of the second air supply branch is connected to the second annular air supply pipe, and the other end is connected to the second air inlet hole.

[0018] Preferably, it further comprises a third air supply system, wherein the third air supply system is connected to the tower-type grate.

[0019] Preferably, the first gasification furnace body and the second gasification furnace body are both cylindrical structures, and the diameter of the second gasification furnace body is 300 to 500 mm larger than that of the first gasification furnace body, so that the flow rate of the combustible gas in the annular gas channel is controlled below 3 m / s.

[0020] Preferably, the rotating base includes a fixed base, a rotating base, a first gear, a driving motor and a second gear. The fixed base is installed on the ground, the rotating base is rotatably connected to the top of the fixed base, a first gear is provided on the outer periphery of the rotating base, the ash tray is fixedly connected to the top surface of the rotating base, the driving motor is installed on the ground, the output shaft of the driving motor is fixedly connected to the second gear, and the second gear is meshed with the first gear.

[0021] Preferably, it also includes an intelligent control system, which includes an intelligent controller, a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor, a fifth temperature sensor, a sixth temperature sensor, a seventh temperature sensor and an ash carbon content monitor, the first temperature sensor is installed in the drying layer, the second temperature sensor is installed in the pyrolysis layer, the third temperature sensor is installed in the first oxidation layer, the fourth temperature sensor is installed in the first reduction layer, the fifth temperature sensor is installed in the second reduction layer, the sixth temperature sensor is installed in the second oxidation layer, the seventh temperature sensor is installed in the ash layer, and the ash carbon content monitor is installed in the ash layer, and the intelligent controller is connected to the screw feeder, the first air supply system, the second air supply system, the third air supply system, the first circulating water supply equipment, the second circulating water supply equipment and the drive motor signal.

[0022] The present invention further provides a method for using the mixed-suction biomass fixed-bed gasification furnace system as described in any one of the above items, comprising the following steps:

[0023] The screw feeder transports the biomass raw material into the first gasification furnace body through the feed port on the top of the first gasification furnace body;

[0024] After the biomass feedstock enters the first gasification furnace body, the drying layer reduces the moisture content of the biomass feedstock to a level suitable for pyrolysis reaction. The pyrolysis layer pyrolyzes the biomass feedstock into fuel gas, tar, and residual fixed carbon. The first oxidation layer causes the residual fixed carbon and fuel gas to undergo an oxidation reaction with oxygen and generate a first heat. The first heat provides the necessary energy support for the drying layer, pyrolysis layer, and first reduction layer. At the same time, the high temperature can cause the tar to undergo a cracking reaction, greatly reducing the tar content in the fuel gas. The first reduction layer causes the remaining substances after the high-temperature oxidation reaction in the first oxidation layer to undergo a reduction reaction to generate combustible gas and coke.

[0025] The annular gas channel reduces the flow rate of the combustible gas and thus can reduce the dust content in the gas. The combustible gas eventually enters the combustible gas collection device through the top of the annular gas channel; the second reduction layer causes the coke from the first reduction layer to undergo a reduction reaction, further generating combustible gas, which enters the combustible gas collection device through the top of the annular gas channel; the second oxidation layer fully burns the carbon in the remaining coke and generates a second heat and carbon dioxide, the second heat being used to maintain its own high temperature and the energy demand of the second reduction layer; the carbon dioxide rises to the second reduction layer as a reactant to participate in the reduction reaction; the residue generated by the reaction in the second oxidation layer falls into the ash layer, and the tower-shaped grate introduces air into the ash layer to further oxidize any incompletely reacted substances that may remain in the ash;

[0026] The rotating base drives the ash pan to rotate, so that the ash can be evenly discharged through the ash removal channel formed with the second gasification furnace body.

[0027] Compared with the prior art, the present invention has achieved the following technical effects:

[0028] The present invention provides a mixed-suction biomass fixed-bed gasification furnace system and a method for use thereof. The feeding mechanism can ensure that biomass raw materials can stably and continuously enter the gasification furnace system, provide a material basis for subsequent gasification reactions, and ensure the continuity of the entire gasification process.

[0029] The layered structure of the first gasifier, consisting of a drying layer, a pyrolysis layer, a first oxidation layer, and a first reduction layer, sequentially arranged from top to bottom, allows the biomass feedstock to be processed stepwise according to a specific process. Each layer has a clear division of labor, which improves the efficiency and quality of biomass gasification and avoids chaotic reactions within the furnace that could waste resources and reduce efficiency. The drying layer effectively separates moisture from the biomass feedstock, reducing its hindrance to the subsequent pyrolysis reaction, improving the efficiency and quality of the pyrolysis reaction while also minimizing the energy loss associated with excess moisture, creating favorable conditions for subsequent efficient gasification. Furthermore, as the fuel's moisture passes through the first and second reduction zones along with the fuel gas, this design allows the water vapor in the fuel to participate in the reduction reaction, increasing the H2 content and calorific value of the fuel gas. This design also facilitates subsequent chemical processes such as methanol production, broadening the range of gas applications. Under a suitable high-temperature environment, the biomass feedstock undergoes pyrolysis in the pyrolysis layer, producing a variety of intermediate products. These products provide the foundation for subsequent oxidation and reduction reactions, serving as a crucial intermediate step in converting biomass into usable fuel gas. On the one hand, the heat generated by the oxidation reaction in the first oxidation layer meets the energy needs of the other reaction layers, ensuring that the different reaction layers react under appropriate temperature conditions. On the other hand, the high temperature of the first oxidation layer causes tar to crack, which reduces the tar content in the gas, improves the cleanliness and quality of the gas, and prevents the adverse effects of tar on the system, such as blockage.

[0030] The sealed connection and communication design between the first gasification furnace body and the second gasification furnace body ensures the orderly flow of gas and materials between the two gasification furnace bodies. The annular gas channel not only plays the role of transporting combustible gas, but also has a certain regulating effect on gas flow rate, etc., which can effectively prevent the gas from carrying ash and greatly reduce the dust content in the gas. It is connected with the combustible gas collection device to ensure that the combustible gas can be effectively collected for subsequent utilization.

[0031] The second reduction layer further processes the coke generated from the first reduction layer, converting the coke into combustible gas, thereby significantly increasing gas production and improving the energy output efficiency of the entire gasifier system.

[0032] The second oxidation layer achieves full combustion of coke, and the heat generated maintains the high-temperature environment required for itself and the adjacent reaction layer. At the same time, carbon dioxide participates in the reduction reaction to achieve the recycling of materials, which is beneficial to improving the energy utilization and reaction efficiency of the entire gasification process.

[0033] The residue layer can effectively collect the residue after the reaction, preventing it from accumulating in the furnace and affecting the normal operation of the system, ensuring the continuous and stable operation of the gasifier, and facilitating the subsequent treatment and cleaning of the residue. Bringing air into the ash layer helps to further oxidize any incompletely reacted substances that may remain in the ash, reducing the carbon content in the ash and improving the utilization rate of biomass. At the same time, it can maintain a suitable environment within the ash layer, which is conducive to the stable operation of the entire gasification process. The formed ash removal channel facilitates the smooth discharge of ash from the gasifier, enabling the system to operate continuously and stably, and preventing excessive accumulation of ash in the lower part of the furnace body that affects the performance of the gasifier. The fixed connection between the tower-type grate and the ash pan ensures the stability and coordinated working performance of the entire lower structure. The rotating base connection method allows the ash pan to rotate stably, which helps to evenly discharge ash, prevent localized accumulation of ash, and ensure the smooth progress of the ash removal process and the long-term stable operation of the gasifier system. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 A front cross-sectional view of the mixed-suction biomass fixed-bed gasification furnace system provided by the present invention;

[0036] Figure 2 A layered schematic diagram of the mixed-suction biomass fixed-bed gasification furnace system provided by the present invention;

[0037] In the figure: 1. feeding mechanism; 2. first gasification furnace body; 21. drying layer; 22. pyrolysis layer; 23. first oxidation layer; 24. first reduction layer; 25. first annular air supply pipe; 26. first air inlet hole; 27. first ignition hole; 28. first water-cooling jacket; 3. second gasification furnace body; 31. annular gas channel; 32. second reduction layer; 33. second oxidation layer; 34. ash layer; 35. second annular air supply pipe; 36. second air inlet hole; 37. second ignition hole; 38. second water-cooling jacket; 4. tower-type grate; 5. ash tray; 6. rotating base; 61. fixed base; 62. rotating base; 63. second gear; 64. driving motor; 7. third temperature sensor; 8. fourth temperature sensor; 9. fifth temperature sensor. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0039] The purpose of the present invention is to provide a mixed-suction biomass fixed-bed gasification furnace system and a method of use to solve the problems existing in the above-mentioned prior art. It has a simple structure, is easy to use, effectively improves the utilization efficiency of biomass energy, effectively reduces the tar content of the fuel gas, and effectively reduces the dust content of the fuel gas.

[0040] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Example 1

[0042] The present embodiment provides a mixed-suction biomass fixed-bed gasification furnace system, comprising: a feeding mechanism 1, a first gasification furnace body 2, a second gasification furnace body 3, a tower-shaped grate 4, an ash tray 5 and a rotating base 6. The feeding mechanism 1 is used to transport biomass raw materials; a feeding port is provided on the top of the first gasification furnace body 2, and the feeding mechanism 1 transports the biomass raw materials into the first gasification furnace body 2 through the feeding port. A drying layer 21, a pyrolysis layer 22, a first oxidation layer 23 and a first reduction layer 24 are sequentially provided in the first gasification furnace body 2 from top to bottom. The drying layer 21 is used to dry the biomass raw materials and reduce the humidity of the biomass raw materials to a level where a pyrolysis reaction occurs, and the pyrolysis layer 22 The first reduction layer 24 is used to provide a high-temperature environment to pyrolyze the biomass raw materials into fuel gas, tar and residual fixed carbon. The first oxidation layer 23 is used to provide oxygen supply and high-temperature environment to allow the residual fixed carbon and fuel gas to undergo oxidation reaction with oxygen and generate first heat. The first heat provides energy support for the drying layer 21, the pyrolysis layer 22 and the first reduction layer 24, and can also cause the tar to undergo cracking reaction. The first reduction layer 24 is used to provide a reducing atmosphere to reduce the remaining substances after the high-temperature oxidation reaction of the first oxidation layer 23 and generate combustible gas and coke. The second gasification furnace body 3 includes an annular fuel gas channel 31, a second reduction layer 32, The second oxidation layer 33 and the ash layer 34, the bottom of the first gasification furnace body 2 extends into the top of the second gasification furnace body 3 and is sealed and connected to the second gasification furnace body 3, the space between the first gasification furnace body 2 and the second gasification furnace body 3 forms an annular gas channel 31, the top of the annular gas channel 31 is connected to the combustible gas collecting device so that the combustible gas enters the combustible gas collecting device after passing through the annular gas channel 31, the second reduction layer 32 is used to cause the coke to undergo a reduction reaction to produce combustible gas, the second oxidation layer 33 is used to provide oxygen and a high temperature environment to fully burn the carbon in the remaining coke and produce a second heat and carbon dioxide, and the second heat is used to maintain the first The high temperature of the carbon dioxide layer 33 provides energy for the second reduction reaction layer. Carbon dioxide rises to the second reduction layer 32 and participates in the reduction reaction as a reactant. The ash layer 34 collects the residue produced by the second oxidation reaction layer. A tower-shaped grate 4 is positioned below the second gasification furnace body 3, and its top extends into the ash layer 34 to allow air to flow into the ash layer 34. An ash pan 5 is positioned below the second gasification furnace body 3 and between the two bodies, forming an ash removal channel. The bottom of the tower-shaped grate 4 is fixedly connected to the ash pan 5. The bottom of the rotating base 6 is fixedly connected to the ground, and the driving end of the rotating base 6 is fixedly connected to the ash pan 5 to drive the ash pan 5 to rotate. The feeding mechanism 1 ensures that biomass feedstock can enter the gasification furnace system stably and continuously, providing the material foundation for subsequent gasification reactions and ensuring the continuity of the entire gasification process. The layered structural design enables the biomass feedstock to be processed step by step according to a specific process. Each layer has a clear division of labor, which is conducive to improving the efficiency and quality of biomass gasification and avoiding chaotic reactions of feedstock within the furnace, which would waste resources and reduce efficiency.The drying layer 21 effectively separates moisture from the biomass feedstock, reducing its hindrance to the subsequent pyrolysis reaction, improving the efficiency and quality of the pyrolysis reaction, and simultaneously reducing the energy loss that may be caused by excessive moisture, creating favorable conditions for the subsequent efficient gasification reaction. Furthermore, the moisture in the fuel passes through the first and second reduction zones along with the fuel gas. This design allows the water vapor in the fuel to participate in the reduction reaction, increasing the H2 ratio in the fuel gas (generally, the H2 ratio in air vaporization is about 8-12% by volume; water vapor participation in the gasification reaction can increase the H2 ratio to 15-25% by volume), improving the calorific value of the fuel gas, and facilitating subsequent chemical processes such as methanol production, thus expanding the range of fuel gas applications. Under a suitable high-temperature environment, the biomass feedstock undergoes pyrolysis in the pyrolysis layer, generating a variety of intermediate products. These products provide the foundation for subsequent oxidation and reduction reactions, serving as an important intermediate step in converting biomass into usable fuel gas. On the one hand, the first heat generated by the oxidation reaction in the first oxidation layer 23 meets the energy needs of the other reaction layers, ensuring that the different reaction layers react under appropriate temperature conditions. On the other hand, the high temperature of the first oxidation layer 23 causes tar to undergo cracking reactions, reducing the tar content in the fuel gas, improving its cleanliness and quality, and preventing adverse effects such as tar clogging the system. Under specific environmental conditions, the remaining materials after the oxidation reaction complete a reduction reaction in the first reduction layer 24, generating combustible gas, increasing fuel gas production. The resulting coke, as a partial product, can enter the subsequent reaction zone and further participate in the reaction, improving biomass utilization. The sealed connection and interconnected design between the first gasifier body 2 and the second gasifier body 3 ensures the orderly flow of gases and materials between the two gasifier bodies. The annular fuel gas channel 31 not only transports fuel gas but also regulates gas flow rate, effectively preventing ash from entering the fuel gas and significantly reducing dust content. It is connected to the fuel gas collection device, ensuring that fuel gas can be effectively collected for subsequent utilization. The second reduction layer 32 further processes the coke generated in the first reduction layer 24, converting it into fuel gas, thereby significantly increasing fuel gas production and enhancing the energy efficiency of the entire gasifier system. The second oxidation layer 33 achieves full combustion of coke, and the heat generated maintains the high temperature environment required by itself and the adjacent reaction layer. At the same time, the carbon dioxide participates in the reduction reaction to achieve material recycling, which is beneficial to improving the energy utilization and reaction efficiency of the entire gasification process. The residue layer can effectively collect the residue after the reaction, preventing the residue from accumulating in the furnace and affecting the normal operation of the system, ensuring the continuous and stable operation of the gasifier, and facilitating the subsequent treatment and cleaning of the residue. The introduction of air into the ash layer 34 helps to further oxidize the incompletely reacted substances that may remain in the ash, reduce the carbon content in the ash, and improve the utilization rate of biomass. At the same time, it can maintain a suitable environment inside the ash layer 34, which is beneficial to the stable operation of the entire gasification process.The resulting ash removal channel facilitates the smooth discharge of ash from the gasifier, enabling continuous and stable system operation and preventing excessive ash accumulation in the lower portion of the furnace, which could impact gasifier performance. The fixed connection between the tower-shaped grate 4 and the ash pan 5 ensures the stability and interoperability of the entire lower structure. The connection to the rotating base 6 allows for stable rotation of the ash pan 5, facilitating even ash discharge and preventing localized accumulation, ensuring smooth ash removal and the long-term stable operation of the gasifier system.

[0043] In a preferred solution of this embodiment, the mixed-suction biomass fixed-bed gasification furnace system further includes a first water-cooling jacket 28, a first circulating water supply device, a second water-cooling jacket 38 and a second circulating water supply device. The first water-cooling jacket 28 is arranged on the outside of the portion of the first gasification furnace body 2 extending out of the second gasification furnace body 3, and the first water-cooling jacket 28 is connected to the first circulating water supply device. The second water-cooling jacket 38 is arranged on the outside of the second gasification furnace body 3, and the second water-cooling jacket 38 is connected to the second circulating water supply device. The first water-cooling jacket 28 and the second water-cooling jacket 38 respectively cool and protect the first gasification furnace body 2 and the second gasification furnace body 3. Cold water enters the first water-cooling jacket 28 and the second water-cooling jacket 38 from the bottom and high-temperature hot water flows out from the top. During operation, the circulating water always fills the water-cooling jacket and is connected to the circulating water supply device to achieve circulating cooling, thereby preventing the furnace body from being damaged due to overheating due to high temperature and extending the service life of the equipment. At the same time, the heat absorbed by the circulating water can also be utilized to improve the overall energy utilization efficiency of the system.

[0044] In a preferred solution of this embodiment, the feeding mechanism 1 is a screw feeder, which can effectively control the feeding speed and feeding amount to ensure that the biomass raw materials enter the first gasification furnace body 2 evenly and stably, which is beneficial to maintaining the stability and continuity of the reaction in the gasification furnace and avoiding interference with the gasification process due to unstable feeding.

[0045] In a preferred scheme of this embodiment, the mixed-suction biomass fixed-bed gasification furnace system also includes a first air supply system, a first annular air supply pipe 25 and a plurality of first air supply branches. The first gasification furnace body 2 is provided with a plurality of first ignition holes 27 and a plurality of first air inlet holes 26. The first ignition holes 27 correspond to the bottom position of the first oxidation layer 23, and the first air inlet holes 26 correspond to the middle position of the first oxidation layer 23. The first annular air supply pipe 25 is sleeved on the outside of the first gasification furnace body 2 and is connected to the output end of the first air supply system. One end of the first air supply branch is connected to the first annular air supply pipe 25, and the other end is connected to the first air inlet hole 26. Through the reasonably set air supply system structure and the connection method with the gasification furnace body, the air can be accurately transported to the required position of the first oxidation layer 23 to provide sufficient oxygen for the oxidation reaction. The degree and rate of the oxidation reaction can be controlled by adjusting the air supply system to ensure the stable operation of the first oxidation layer 23, thereby improving the performance of the entire gasification furnace system.

[0046] In a preferred solution of this embodiment, the mixed-suction biomass fixed-bed gasification furnace system also includes a second air supply system, a second annular air supply pipe 35 and multiple second air supply branches. The second gasification furnace body 3 is provided with multiple second ignition holes 37 and multiple second air inlet holes 36. The second ignition holes 37 correspond to the bottom position of the second oxidation layer 33, and the second air inlet holes 36 correspond to the middle position of the second oxidation layer 33. The second annular air supply pipe 35 is sleeved on the outside of the second gasification furnace body 3 and is connected to the output end of the second air supply system. One end of the second air supply branch is connected to the second annular air supply pipe 35, and the other end is connected to the second air inlet hole 36. Similar to the first air supply system, this design can provide a suitable oxygen supply for the second oxidation layer 33. Through a fine structural layout, the reaction conditions of the second oxidation layer 33 can be accurately controlled, which helps to improve the reaction efficiency of the second oxidation layer 33, improve the reaction process of the entire gasification furnace system, and enhance the overall performance of the system.

[0047] In a preferred solution of this embodiment, the mixed-suction biomass fixed-bed gasification furnace system also includes a third air supply system, which is connected to the tower-type grate 4. The third air supply system is connected to the tower-type grate 4, and can effectively provide an appropriate amount of air to the ash layer 34 and the space above it, thereby optimizing the combustion and gasification conditions in the area, reducing the residue of unreacted substances, further improving the conversion efficiency of biomass, and ensuring that the entire gasification process is more complete and efficient.

[0048] In a preferred embodiment of this invention, both the first gasifier body 2 and the second gasifier body 3 are cylindrical structures, with the diameter of the second gasifier body 3 being 300-500 mm larger than that of the first gasifier body 2. This ensures that the flow rate of the combustible gas within the annular gas channel 31 is controlled below 3 m / s. The cylindrical structure facilitates uniform internal airflow distribution and stable reactions. A reasonable diameter difference design effectively controls the flow rate of the combustible gas within the annular gas channel 31. Reducing the flow rate reduces impurities such as dust carried by the gas, improving gas quality, and facilitating sufficient gas mixing and reaction, thereby enhancing the overall system's performance.

[0049] In a preferred embodiment of this invention, the rotating base 6 includes a fixed base 61, a rotating base 62, a first gear, a drive motor 64, and a second gear 63. The fixed base 61 is mounted on the ground, the rotating base 62 is rotatably connected to the top of the fixed base 61, and a first gear is provided on the outer periphery of the rotating base 62. The ash pan 5 is fixedly connected to the top surface of the rotating base 62. The drive motor 64 is mounted on the ground, and the output shaft of the drive motor 64 is fixedly connected to the second gear 63. The second gear 63 is meshed with the first gear. This gear transmission structure of the rotating base 6 can provide stable power transmission, ensuring smooth and reliable rotation of the ash pan 5. By adjusting the gear parameters, the rotation speed of the ash pan 5 can be changed to meet the ash removal requirements under different operating conditions, ensuring the normal operation and ash removal efficiency of the gasifier.

[0050] In a preferred solution of this embodiment, the mixed-suction biomass fixed-bed gasification furnace system also includes an intelligent control system, which includes an intelligent controller, a first temperature sensor, a second temperature sensor, a third temperature sensor 7, a fourth temperature sensor 8, a fifth temperature sensor 9, a sixth temperature sensor, a seventh temperature sensor and an ash carbon content monitor. The first temperature sensor is installed in the drying layer 21, the second temperature sensor is installed in the pyrolysis layer 22, the third temperature sensor 7 is installed in the first oxidation layer 23, the fourth temperature sensor 8 is installed in the first reduction layer 24, the fifth temperature sensor 9 is installed in the second reduction layer 32, the sixth temperature sensor is installed in the second oxidation layer 33, the seventh temperature sensor is installed in the ash layer 34, and the ash carbon content monitor is installed in the ash layer 34. The intelligent controller is connected to the screw feeder, the first air supply system, the second air supply system, the third air supply system, the first circulating water supply equipment, the second circulating water supply equipment and the drive motor 64. The intelligent control system can obtain temperature information of each reaction layer and key position and ash carbon content information in real time. Based on this data, the intelligent controller can automatically adjust operating parameters such as feed rate, air volume of the air supply system, circulating water flow, and 64-degree speed of the drive motor to achieve precise control and real-time optimization of the entire gasification process, maximize gasification efficiency and energy utilization, reduce energy consumption, and ensure stable, efficient, and energy-saving operation of the system.

[0051] Example 2

[0052] This embodiment also provides a method for using the mixed-suction biomass fixed-bed gasification furnace system as in the first embodiment, comprising the following steps:

[0053] Biomass pretreatment: Biomass raw materials are pretreated and crushed to a particle size of 2-5 cm to facilitate better reaction in the gasifier. This step can make the raw materials more uniform during subsequent drying and pyrolysis processes, which is conducive to improving the efficiency of the entire gasification process.

[0054] Feeding: A screw feeder is used to slowly and evenly deliver the pretreated biomass feedstock into the first gasifier body 2 through the feed port at the top of the first gasifier body 2. The screw feeder's speed can be adjusted based on parameters such as the temperature and pressure within the gasifier to ensure that the feed rate matches the gasification reaction rate, maintaining stable operation of the gasification process.

[0055] First gasification furnace 2 reaction control:

[0056] Drying layer 21: After entering the first gasification furnace body 2, the biomass raw materials first reach the drying layer 21. The heat generated during the gasification process evaporates the water at 150-250°C, reducing the humidity of the biomass raw materials to a level suitable for the pyrolysis reaction, ensuring that the subsequent pyrolysis reaction can proceed smoothly.

[0057] Pyrolysis Layer 22: The dried feedstock enters the pyrolysis layer 22, which provides a high-temperature environment of 250-600°C, pyrolyzing the biomass into gas, tar, and residual fixed carbon. The gas and tar produced in this stage form the basis for subsequent reactions. The stability and efficiency of the pyrolysis process directly impact the gas quality and yield of the entire gasification process.

[0058] First Oxidation Layer 23: The pyrolysis products enter this layer. The first air supply system delivers air to this layer through the first annular air supply duct 25 and the first air supply branch duct, ensuring an oxygen supply. This layer is maintained at a temperature of 1000-1100°C, allowing the remaining fixed carbon and fuel gas to undergo an oxidation reaction with oxygen, generating primary heat. This primary heat provides the necessary energy for the drying layer 21, pyrolysis layer 22, and first reduction layer 24. Furthermore, the high temperature causes tar to crack, significantly reducing the tar content in the fuel gas.

[0059] First Reduction Layer 24: This layer provides a reducing atmosphere, either oxygen-deficient or weakly oxidizing, at a temperature controlled between 600°C and 800°C. This atmosphere allows the remaining substances after the high-temperature oxidation reaction in the first oxidation layer 23 to undergo a reduction reaction, generating combustible gas and coke. This combustible gas further increases the gas production of the gasifier system, while the coke enters the second gasifier body 3 for further reaction.

[0060] Second gasification furnace 3 reaction control:

[0061] Annular gas channel 31: Some combustible gas and unreacted substances generated by the first gasifier body 2 enter the second gasifier body 3 through the bottom. The annular gas channel 31 between the first and second gasifier bodies 2 and 3 controls the flow rate of the combustible gas, reducing it to below 3 m / s (for a mixed-intake gasifier equipped with a 10 t / h boiler, the gas flow rate is approximately 0.6 m / s). Through the rational design of the flow area, the dust content in the gas is greatly reduced. The gas ultimately enters the combustible gas collection device through the top of the annular gas channel 31.

[0062] Second reduction layer 32: The coke from the first reduction layer 24 enters the second reduction layer 32 and undergoes a reduction reaction in an environment of 600-800°C, further generating combustible gas and increasing the total gas production.

[0063] Second Oxidation Layer 33: The second air supply system provides sufficient oxygen to maintain a high temperature in the second oxidation layer 33, allowing the carbon in the remaining coke to fully combust and generate secondary heat and carbon dioxide. This secondary heat is used to maintain the temperature and energy requirements of the second reduction layer 32. Carbon dioxide rises to the second reduction layer 32 and participates in the reduction reaction as a reactant, achieving material recycling and improving energy efficiency.

[0064] Ash layer 34: The residue produced by the reaction in the second oxidation layer 33 falls into the ash layer 34 for collection. The top of the tower grate 4 extends into the ash layer 34. The third air supply system introduces air into the ash layer 34 through the tower grate 4, helping to further oxidize any unreacted substances that may remain in the ash. The rotating base 6 drives the ash pan 5 to rotate, allowing the ash to be evenly discharged through the ash removal channel formed with the second gasification furnace body 3.

[0065] The mixed-suction biomass fixed-bed gasifier system provided by the present invention has a gasification efficiency that is much higher than that of a traditional gasifier, and is increased from 75% to 80%.

[0066] Temperature regulation and intelligent control:

[0067] Temperature sensor: The first temperature sensor, the second temperature sensor, the third temperature sensor 7, the fourth temperature sensor 8, the fifth temperature sensor 9, the sixth temperature sensor and the seventh temperature sensor are respectively installed in the drying layer 21, the pyrolysis layer 22, the first oxidation layer 23, the first reduction layer 24, the second reduction layer 32, the second oxidation layer 33 and the ash layer 34 to monitor the temperature of each layer in real time.

[0068] Ash carbon content monitor: The ash carbon content monitor installed in the ash layer 34 monitors the carbon content in the ash in real time.

[0069] Intelligent controller: The intelligent controller is connected to the screw feeder, the first air supply system, the second air supply system, the third air supply system, the first circulating water supply device, the second circulating water supply device, and the drive motor 64. Based on data from various temperature sensors and the ash carbon content monitor, the intelligent controller automatically adjusts parameters such as the feed rate, the air volume of each air supply system, the circulating water flow rate, and the speed of the drive motor 64, achieving precise control and real-time optimization of the entire gasification process, ensuring that the gasification process operates under optimal conditions.

[0070] Water Cooling System Operation: The first and second water cooling jackets 28 and 38 surround the portion of the first gasifier body 2 extending beyond the second gasifier body 3, respectively, and are connected to the first and second circulating water supply devices, respectively. Circulating water passes through the jackets, absorbing heat from the furnace body, preventing damage from overheating and extending the service life of the equipment. The absorbed heat is then fed into the subsequent boiler feedwater system, improving system thermal efficiency.

[0071] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A mixed-suction biomass fixed-bed gasification furnace system, characterized by: include: A feeding mechanism (1), the feeding mechanism (1) is used to transport biomass raw materials; A first gasification furnace body (2), wherein a feed port is provided at the top of the first gasification furnace body (2), and the feeding mechanism (1) transports the biomass raw material into the first gasification furnace body (2) through the feed port. A drying layer (21), a pyrolysis layer (22), a first oxidation layer (23) and a first reduction layer (24) are sequentially provided in the first gasification furnace body (2) from top to bottom. The drying layer (21) is used to dry the biomass raw material and reduce the humidity of the biomass raw material to a level where a pyrolysis reaction occurs. The pyrolysis layer (22) is used to provide a high-temperature environment to reduce the biomass raw material to a high temperature. The raw material is pyrolyzed into fuel gas, tar and residual fixed carbon, the first oxidation layer (23) is used to provide oxygen supply and high temperature environment so that the residual fixed carbon and the fuel gas undergo oxidation reaction with oxygen and generate first heat, the first heat provides energy support for the drying layer (21), the pyrolysis layer (22) and the first reduction layer (24), and can also cause the tar to undergo cracking reaction; the first reduction layer (24) is used to provide a reducing atmosphere so as to reduce the remaining substances after the high temperature oxidation reaction of the first oxidation layer (23) and generate combustible gas and coke; The second gasification furnace body (3) comprises an annular gas channel (31), a second reduction layer (32), a second oxidation layer (33) and an ash layer (34) arranged in sequence from top to bottom, the bottom of the first gasification furnace body (2) extends into the top of the second gasification furnace body (3) and is sealed and connected to the second gasification furnace body (3), the space between the first gasification furnace body (2) and the second gasification furnace body (3) forms the annular gas channel (31), the top of the annular gas channel (31) is connected to the combustible gas collecting device so that the combustible gas passes through the annular gas channel (31) and is connected to the combustible gas collecting device. The gas passes through the gas channel (31) and enters the combustible gas collection device. The second reduction layer (32) is used to cause the coke to undergo a reduction reaction to generate combustible gas. The second oxidation layer (33) is used to provide oxygen and a high-temperature environment to fully burn the carbon in the remaining coke and generate a second heat and carbon dioxide. The second heat is used to maintain the high-temperature environment of the second oxidation layer (33) and provide energy for the second reduction reaction layer. The carbon dioxide rises to the second reduction layer (32) and participates in the reduction reaction as a reactant of the reduction reaction. The ash layer (34) is used to collect the residue generated by the second oxidation reaction layer. a tower-shaped grate (4), the tower-shaped grate (4) being arranged below the second gasification furnace body (3), and the top of the tower-shaped grate extending into the ash layer (34) to allow air to flow into the ash layer (34); an ash tray (5), the ash tray (5) being arranged below the second gasification furnace body (3) and forming an ash removal channel between the second gasification furnace body (3), and the bottom of the tower-shaped grate (4) being fixedly connected to the ash tray (5); as well as A rotating base (6) is provided, wherein the bottom of the rotating base (6) is fixedly connected to the ground, and the driving end of the rotating base (6) is fixedly connected to the ash tray (5) to drive the ash tray (5) to rotate.

2. The mixed-suction biomass fixed-bed gasification furnace system according to claim 1, characterized in that: The invention also includes a first water-cooling jacket (28), a first circulating water supply device, a second water-cooling jacket (38) and a second circulating water supply device, wherein the first water-cooling jacket (28) is arranged on the outside of the portion of the first gasification furnace body (2) extending out of the second gasification furnace body (3), and the first water-cooling jacket (28) is connected to the first circulating water supply device, and the second water-cooling jacket (38) is arranged on the outside of the second gasification furnace body (3), and the second water-cooling jacket (38) is connected to the second circulating water supply device.

3. The mixed-suction biomass fixed-bed gasification furnace system according to claim 2, characterized in that: The feeding mechanism (1) is a screw feeder.

4. The mixed-suction biomass fixed-bed gasification furnace system according to claim 3, characterized in that: The invention also includes a first air supply system, a first annular air supply pipe (25) and a plurality of first air supply branches. The first gasification furnace body (2) is provided with a plurality of first ignition holes (27) and a plurality of first air inlet holes (26). The first ignition holes (27) correspond to the bottom position of the first oxidation layer (23), and the first air inlet holes (26) correspond to the middle position of the first oxidation layer (23). The first annular air supply pipe (25) is sleeved on the outside of the first gasification furnace body (2) and is connected to the output end of the first air supply system. One end of the first air supply branch is connected to the first annular air supply pipe (25), and the other end is connected to the first air inlet hole (26).

5. The mixed-suction biomass fixed-bed gasification furnace system according to claim 4, characterized in that: The invention also includes a second air supply system, a second annular air supply pipe (35) and a plurality of second air supply branches. The second gasification furnace body (3) is provided with a plurality of second ignition holes (37) and a plurality of second air inlet holes (36). The second ignition holes (37) correspond to the bottom position of the second oxide layer (33), and the second air inlet holes (36) correspond to the middle position of the second oxide layer (33). The second annular air supply pipe (35) is sleeved on the outside of the second gasification furnace body (3) and is connected to the output end of the second air supply system. One end of the second air supply branch is connected to the second annular air supply pipe (35), and the other end is connected to the second air inlet hole (36).

6. The mixed-suction biomass fixed-bed gasification furnace system according to claim 5, characterized in that: It also includes a third air supply system, and the third air supply system is connected to the tower-shaped grate (4).

7. The mixed-suction biomass fixed-bed gasification furnace system according to claim 6, characterized in that: The first gasification furnace body (2) and the second gasification furnace body (3) are both cylindrical structures, and the diameter of the second gasification furnace body (3) is 300 to 500 mm larger than the diameter of the first gasification furnace body (2), so that the flow rate of the combustible gas in the annular gas channel (31) is controlled to be below 3 m / s.

8. The mixed-suction biomass fixed-bed gasification furnace system according to claim 7, characterized in that: The rotating base (6) comprises a fixed base (61), a rotating base (62), a first gear, a driving motor (64) and a second gear (63); the fixed base (61) is installed on the ground; the rotating base (62) is rotatably connected to the top of the fixed base (61); a first gear is provided on the outer periphery of the rotating base (62); the ash tray (5) is fixedly connected to the top surface of the rotating base (62); the driving motor (64) is installed on the ground; an output shaft of the driving motor (64) is fixedly connected to the second gear (63); and the second gear (63) is meshed with the first gear.

9. The mixed-suction biomass fixed-bed gasification furnace system according to claim 1, characterized in that: The invention also includes an intelligent control system, which includes an intelligent controller, a first temperature sensor, a second temperature sensor, a third temperature sensor (7), a fourth temperature sensor (8), a fifth temperature sensor (9), a sixth temperature sensor, a seventh temperature sensor and an ash carbon content monitor, wherein the first temperature sensor is installed on the drying layer (21), the second temperature sensor is installed on the pyrolysis layer (22), the third temperature sensor (7) is installed on the first oxidation layer (23), the fourth temperature sensor (8) is installed on the first reduction layer (24), the fifth temperature sensor (9) is installed on the second reduction layer (32), the sixth temperature sensor is installed on the second oxidation layer (33), the seventh temperature sensor is installed on the ash layer (34), and the ash carbon content monitor is installed on the ash layer (34). The intelligent controller is connected to the screw feeder, the first air supply system, the second air supply system, the third air supply system, the first circulating water supply equipment, the second circulating water supply equipment and the drive motor (64) through signals.

10. A method for using the mixed-suction biomass fixed-bed gasification furnace system according to any one of claims 1 to 9, characterized in that: The following steps are involved: The screw feeder transports the biomass raw material into the first gasification furnace body (2) through the feed port at the top of the first gasification furnace body (2); After the biomass raw material enters the first gasification furnace body (2), the drying layer (21) reduces the humidity of the biomass raw material to a level suitable for pyrolysis reaction, the pyrolysis layer (22) pyrolyzes the biomass raw material into fuel gas, tar and residual fixed carbon, the first oxidation layer (23) causes the residual fixed carbon and fuel gas to undergo oxidation reaction with oxygen and generate first heat, the first heat provides necessary energy support for the drying layer (21), the pyrolysis layer (22) and the first reduction layer (24), and the high temperature can cause the tar to undergo cracking reaction, greatly reducing the tar content in the fuel gas, the first reduction layer (24) causes the remaining substances after the high-temperature oxidation reaction of the first oxidation layer (23) to undergo reduction reaction to generate combustible gas and coke; The annular gas channel (31) reduces the flow rate of the combustible gas and thus reduces the dust content in the gas. The combustible gas eventually enters the combustible gas collecting device through the top of the annular gas channel (31); the second reduction layer (32) causes the coke from the first reduction layer (24) to undergo a reduction reaction, further generating combustible gas. The combustible gas enters the combustible gas collecting device through the top of the annular gas channel (31); the second oxidation layer (33) causes the carbon in the remaining coke to fully burn and generate a second heat and carbon dioxide. The second heat is used to maintain its own high temperature and the energy demand of the second reduction layer (32); the carbon dioxide rises to the second reduction layer (32) and participates in the reduction reaction as a reactant. The residue generated by the reaction of the second oxidation layer (33) falls into the ash layer (34); the tower grate (4) introduces air into the ash layer (34) to further oxidize the incompletely reacted substances that may remain in the ash; The rotating base (6) drives the ash pan (5) to rotate, so that the ash can be evenly discharged through the ash removal channel formed with the second gasification furnace body (3).

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