A biomass production pretreatment and pneumatic conveying system

Abstract

The utility model discloses a kind of biomass production pretreatment and pneumatic conveying system, belong to pneumatic conveying technical field, the conveying system includes crushing section, the crushing section is connected by first conveying mechanism coarse crushing section, the coarse crushing section is connected by second conveying mechanism drying section, the drying section is connected by third conveying mechanism fine crushing section, the discharge end of the fine crushing section is connected by fourth conveying mechanism powder bin, the discharge end of the powder bin is connected by belt conveyor and rotary closed air unloader, the discharge end of the rotary closed air unloader is connected solid gas mixer, the air inlet end of the solid gas mixer is fixedly installed Roots blower, the discharge end of the solid gas mixer is communicated with the feed end of special burner by pipeline, the discharge end of the special burner is adaptively connected boiler, the system is adapted to the characteristics of biomass, guarantee conveying efficient stability and combustion effect, reduce coal consumption and carbon dioxide emission, detail design improves practicality and environmental protection.

Description

Technical Field

[0001] This utility model relates to the field of pneumatic conveying technology, and more specifically, to a biomass production pretreatment and pneumatic conveying system. Background Technology

[0002] Currently, biomass, as a renewable green energy source, has significant value in replacing non-renewable mineral energy, alleviating the pressure of energy depletion, and responding to environmental protection needs. However, biomass has diverse properties (such as significant differences in length, moisture content, and particle size of raw materials like corn cobs, rice husks, straw, and wood chips) and relatively low calorific value. To facilitate subsequent transportation, storage, and combustion, it needs to undergo specialized pretreatment. However, existing technologies lack effective integration of the "production pretreatment - terminal transportation" process for biomass, making it difficult to achieve efficient and integrated utilization.

[0003] In the prior art, utility model patent application number 202422844025.1 discloses a biomass raw material production and processing system. The system includes a crushing section, a coarse crushing section, a drying section, a fine crushing section, a pellet processing section, and a bypass channel. Through the bypass channel and the supporting bypass delivery mechanism, the biomass raw materials can be directly transported to the corresponding processing section according to their properties, which solves the problem of over-processing caused by traditional uniform mixing processing and improves pretreatment efficiency. At the same time, the coarse crushing section is equipped with an anti-clogging variable frequency hopper, a destoner, and an iron remover, and the drying section is equipped with a dust collector and a fan, which optimizes the stability of each stage of pretreatment.

[0004] However, the solutions in the aforementioned existing technologies only focus on the pretreatment stage of biomass raw materials production, without addressing the design of the conveying system for the pretreated materials to the terminal boiler, thus failing to form a complete process of "pretreatment-conveying-terminal energy conversion". In addition, existing independent pneumatic conveying solutions have many compatibility issues: such as failure to design the solid-gas mixing ratio according to the differences in biomass material particle size (micrometer-level and millimeter-level), insufficient sealing performance of the rotary unloader leading to reverse airflow in the pipeline, uneven mixing of materials and air in the solid-gas mixer, severe wear due to lack of wear-resistant treatment of the pipeline, and mismatch between the conveying flow rate and the wind speed of the terminal burner. These problems make it difficult to efficiently and stably convey the pretreated biomass materials to the boiler for energy conversion, ultimately limiting the comprehensive utilization efficiency of biomass energy and failing to fully meet the current green production needs of enterprises to reduce coal consumption and carbon dioxide emissions. Utility Model Content

[0005] To overcome the above deficiencies, this utility model provides a biomass production pretreatment and pneumatic conveying system, which aims to improve the design of the conveying system for pretreated materials to the terminal boiler, thus addressing the problem of the inability to form a complete process of "pretreatment-conveying-terminal energy conversion".

[0006] In a first aspect, this utility model provides a pretreatment for biomass production, including a crushing section and a bypass channel. The crushing section is connected to a coarse crushing section via a first conveying mechanism. The coarse crushing section is connected to a drying section via a second conveying mechanism. The drying section is connected to a fine crushing section via a third conveying mechanism. A fourth conveying mechanism is installed at the discharge end of the fine crushing section. The bypass channel is connected to first to fourth bypass distribution mechanisms and is respectively connected to the first to fourth conveying mechanisms. The coarse crushing section includes an anti-clogging variable frequency hopper, a destoner, an iron remover, and a coarse crusher.

[0007] Secondly, this utility model also provides a pneumatic conveying system, including the above-mentioned biomass production pretreatment and powder silo. One end of the fourth conveying mechanism is connected to the feed end of the powder silo, and the discharge end of the powder silo is connected to the feed end of a rotary closed-air unloader via a belt conveyor. The discharge end of the rotary closed-air unloader is connected to a solid-gas mixer. A Roots blower is fixedly installed at the air inlet end of the solid-gas mixer. The discharge end of the solid-gas mixer is connected to the feed end of a special burner via a pipeline. The discharge end of the special burner is adapted to be connected to a boiler.

[0008] In the preferred embodiment of this utility model, the pressure head of the Roots blower ranges from 20 to 98 kPa, and the pressure head is determined according to the conveying distance and inner diameter of the pipeline; when the material output from the powder silo has a micron-sized particle size, the solid-gas mixing ratio of the system is greater than 10; when the material has a particle size of more than a millimeter, the solid-gas mixing ratio of the system is less than 3.

[0009] In a preferred embodiment of this utility model, the rotary closed-air unloader is provided with sealing blades inside, and the gap between the sealing blades and the inner wall of the housing is less than 0.5mm, which is used to ensure that the air in the pipeline does not flow backwards when the material is conveyed.

[0010] In a preferred embodiment of this utility model, the solid-gas mixer is provided with a spiral guide plate inside, and the pitch of the spiral guide plate is 1-2 times the inner diameter of the solid-gas mixer, which is used to enhance the uniformity of mixing between materials and air.

[0011] In a preferred embodiment of this invention, the inner wall of the pipe is provided with a wear-resistant ceramic coating. The coating thickness is 1-3 mm.

[0012] In the preferred embodiment of this utility model, the nozzle velocity of the special burner is not less than 25 m / s, and the flow velocity of the gas-solid two-phase flow in the pipeline deviates from the nozzle velocity of the special burner by no more than ±2 m / s.

[0013] In a preferred embodiment of this utility model, a pelletizer is installed at the bottom of the powder silo via a feed pipe, and a filter screen is installed at the top of the feed pipe. The filter screen is a circular metal filter screen that effectively filters out particles or impurities with a diameter exceeding 1mm. If these excessive particles and impurities enter the pelletizer 190, they can easily cause wear and jamming of the pelletizing components inside the pelletizer 190, or even damage to the pelletizing mold. The filter screen can prevent such risks in advance, ensuring the operational stability of the pelletizer 190, while also ensuring that the particle size of the material entering the pelletizer 190 is uniform, thus improving the consistency of the final pellet quality.

[0014] In a preferred embodiment of this utility model, a dust collector is installed at the top exhaust port of the pellet mill via a dust collection pipe, and a fan is installed at the exhaust end of the dust collector. The shell of the dust collector is fixed to the top shell of the pellet mill by a bracket, and the height of the bracket allows the dust collection pipe to be arranged at an upward inclination of 10°-15°.

[0015] The beneficial effects of this utility model are as follows: Firstly, the parameters and structural design of the pneumatic conveying system are precisely adapted to the characteristics of biomass. The pressure head of the Roots blower (20-98KPa) can be flexibly adjusted according to the pipeline conveying distance and inner diameter. The rotary closed-loop unloader prevents reverse airflow through sealing blades (with a gap of less than 0.5mm between the blades and the inner wall of the shell). The spiral guide plate inside the solid-gas mixer (with a pitch of 1-2 times the inner diameter) ensures uniform gas-solid mixing. The 1-3mm thick wear-resistant ceramic coating on the inner wall of the pipeline extends its service life. Furthermore, the deviation between the gas-solid two-phase flow velocity in the pipeline and the air velocity at the nozzle of the dedicated burner (not less than 25m / s) is controlled within ±2m. Within a 1 / s range, it perfectly matches the terminal combustion requirements, ensuring conveying efficiency and energy conversion effect; secondly, the detailed design of the system further enhances its practicality and environmental friendliness. The filter screen at the bottom of the powder silo can filter particulate impurities with a particle size of more than 1mm, and the dust collector matched with the pellet mill (the dust collection pipe is arranged at a 10°-15° angle upward) can effectively purify the exhaust gas and reduce dust pollution; thirdly, the overall system can fully adapt to the complexity and diversity of biomass, realize the efficient utilization of biomass resources, significantly reduce coal consumption and carbon dioxide emissions, provide a practical and feasible technical path for green energy development, and has significant economic and environmental benefits. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0017] Figure 1This is a schematic diagram of the structure of a biomass production pretreatment provided by an embodiment of the present invention; Figure 2 A schematic diagram of a pneumatic conveying system is provided for an embodiment of this utility model; Figure 3 This utility model provides a structural schematic diagram of a biomass production pretreatment and pneumatic conveying system.

[0018] In the diagram: 110-Powder silo; 120-Belt conveyor; 130-Rotary closed-loop unloader; 140-Roots blower; 150-Solid-gas mixer; 160-Pipeline; 170-Special burner; 180-Boiler; 190-Pellet mill; 191-Dust collector; 192-Fan. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0020] Please see Figure 1 and Figure 3 This utility model provides a technical solution: a biomass production pretreatment, including a crushing section and a bypass channel. The crushing section is connected to a coarse crushing section through a first conveying mechanism. The coarse crushing section is connected to a drying section through a second conveying mechanism. The drying section is connected to a fine crushing section through a third conveying mechanism. A fourth conveying mechanism is installed at the discharge end of the fine crushing section. The bypass channel is connected to the first to fourth bypass distribution mechanisms and is respectively connected to the first to fourth conveying mechanisms. The coarse crushing section includes an anti-clogging variable frequency hopper, a destoner, an iron remover, and a coarse crusher.

[0021] Please see Figure 2 and Figure 3 This utility model embodiment also provides a pneumatic conveying system, including the above-mentioned biomass production pretreatment and powder silo 110. One end of the fourth conveying mechanism is connected to the feed end of the powder silo 110. The discharge end of the powder silo 110 is connected to the feed end of the rotary closed-air unloader 130 through the belt conveyor 120. The discharge end of the rotary closed-air unloader 130 is connected to the solid-gas mixer 150. The air inlet end of the solid-gas mixer 150 is fixedly installed with a Roots blower 140. The discharge end of the solid-gas mixer 150 is connected to the feed end of a special burner 170 through a pipe 160. The discharge end of the special burner 170 is adapted to be connected to a boiler 180.

[0022] In some specific implementation schemes, the pressure head of the Roots blower 140 ranges from 20 to 98 kPa, and the pressure head is determined based on the conveying distance and inner diameter of the pipeline 160. When the material output from the powder silo 110 has a micron-sized particle size, the solid-gas mixing ratio of the system is greater than 10. When the material has a particle size of more than a millimeter, the solid-gas mixing ratio of the system is less than 3. This ensures that biomass materials of different particle sizes can form a stable gas-solid two-phase flow with air, effectively preventing problems such as material deposition and blockage in the pipeline 160, and significantly improving the adaptability and efficiency of pneumatic conveying.

[0023] In some specific implementations, the rotary air-sealed unloader 130 is equipped with sealing blades inside, with a gap of less than 0.5mm between the sealing blades and the inner wall of the housing. This is to ensure that the air in the pipeline 160 does not flow backward during material conveying, to ensure stable pressure in the pneumatic conveying system, and to avoid insufficient material conveying power due to reverse airflow. At the same time, the good sealing performance can also prevent external impurities from entering the connection between the rotary air-sealed unloader 130 and the pipeline 160, to ensure the purity of the conveyed material, to reduce the wear of the internal components of the rotary air-sealed unloader 130, and to extend its service life.

[0024] In some specific implementation schemes, the solid-gas mixer 150 is equipped with a spiral guide plate inside. The pitch of the spiral guide plate is 1-2 times the inner diameter of the solid-gas mixer 150. This is used to enhance the uniformity of mixing between the material and the air. After the uniform gas-solid two-phase flow enters the pipeline 160, it can further improve the conveying stability and lay the foundation for the uniformity of combustion of the material entering the dedicated burner 170.

[0025] In some specific implementation schemes, the inner wall of pipe 160 is provided with a wear-resistant ceramic coating with a coating thickness of 1-3mm, which effectively reduces the wear on the inner wall of pipe 160, extends the service life of pipe 160, reduces material waste and safety hazards caused by wear and leakage of pipe 160, and at the same time reduces the frequency of maintenance and replacement of pipe 160, thereby reducing system operation and maintenance costs.

[0026] In some specific implementation schemes, the nozzle velocity of the dedicated burner 170 is not less than 25 m / s, and the flow velocity of the gas-solid two-phase flow in the pipeline 160 deviates from the nozzle velocity of the dedicated burner 170 by no more than ±2 m / s. This allows for rapid fusion with the high-speed airflow at the nozzle, preventing uneven distribution of materials within the dedicated burner 170 due to velocity differences. This ensures complete combustion of biomass materials within the dedicated burner 170, improves energy conversion efficiency, and prevents carbon deposits caused by incomplete combustion from adhering to the inner wall of the boiler 180, thus ensuring the normal operation of the boiler 180.

[0027] In some specific implementation schemes, a pellet mill 190 is installed at the feed end of the powder silo 110 via a feed pipe, and a filter screen is installed at the top of the feed pipe. The filter screen is a circular metal filter screen.

[0028] In some specific implementation schemes, a dust collector 191 is installed at the top exhaust port of the pellet mill 190 through a dust collection pipe. A fan 192 is installed at the exhaust end of the dust collector 191. The shell of the dust collector 191 is fixed to the top shell of the pellet mill 190 by a bracket. The height of the bracket allows the dust collection pipe to be arranged at an upward inclination of 10°-15°, which can prevent dust from accumulating and clogging inside the dust collection pipe, ensure the long-term stable operation of the dust collection system, and reduce the workload of pipe cleaning and maintenance.

[0029] Working principle: Biomass raw materials first enter the production pretreatment system: If the length of the raw material exceeds the coarse crushing requirement, it is first crushed in the crushing section, and then conveyed to the anti-clogging variable frequency hopper of the coarse crushing section through the first conveying mechanism; If the length of the raw material meets the coarse crushing requirement, it is directly put into the bypass channel. After being detected by the detection element on the bypass channel, it is conveyed to the first conveying mechanism, second conveying mechanism, third conveying mechanism, or fourth conveying mechanism through the corresponding first bypass distribution mechanism, second bypass distribution mechanism, third bypass distribution mechanism, or fourth bypass distribution mechanism, respectively, to avoid over-processing of the raw material. Raw materials entering the anti-clogging variable frequency hopper are temporarily stored and real-time blocked, with the feeding speed adjusted according to production capacity. The raw materials then pass through a conveyor channel, sequentially passing through a destoner to remove sand and gravel impurities, and an iron remover to remove metal impurities. They then enter a coarse crusher to be pulverized to the required length for subsequent processing. The pulverized raw materials are then conveyed via a second conveyor to the dryer in the drying section. The dryer controls the moisture content of the raw materials to 10%-20% (to meet the requirements for subsequent processing and combustion) through direct or indirect heating. The dried raw materials are then conveyed via a third conveyor to a pulverizing bin in the fine pulverizing section for temporary storage. From there, they are sent to the fine pulverizer to be pulverized to the target particle size. The finely pulverized raw materials then pass through a fourth conveyor... The conveying mechanism transports the raw materials to the powder silo 110 for temporary storage. Some of the raw materials enter the pellet mill 190 through the feed pipe at the bottom of the powder silo 110 (the metal circular filter at the top of the feed pipe will filter out particles or impurities with a diameter greater than 1mm, ensuring that the raw materials entering the pellet mill 190 meet the pelletizing requirements). The pellet mill 190 presses the raw materials into granular materials with higher density. The gas discharged from the exhaust port at the top of the pellet mill 190 is transported to the dust collector 191 for purification through the dust collector pipe (the dust collector 191 is fixed to the outer shell of the pellet mill 190 by the bracket, and the height of the bracket makes the dust collector pipe inclined upward at 10°-15°). The purified gas is then discharged by the fan 192, completing the production pretreatment process.

[0030] After pretreatment, the material enters the pneumatic conveying system: the material in the powder silo 110 is conveyed to the rotary closed-air unloader 130 via the belt conveyor 120. The rotary closed-air unloader 130 ensures that the air in the pipeline 160 does not flow backward through the internal sealing blades (the gap between the sealing blades and the inner wall of the shell is less than 0.5mm), and at the same time conveys the material to the solid-gas mixer 150 in the specified direction. The Roots blower 140 (pressure head range is 20-98KPa, the pressure head is determined according to the conveying distance and inner diameter of the pipeline 160) introduces sufficient air into the solid-gas mixer 150. The solid-gas mixer 150 is reinforced by the internal spiral guide plate (the pitch is 1-2 times the inner diameter of the solid-gas mixer 150). The uniformity of mixing between the material and air forms a gas-solid two-phase flow that meets the requirements (when the material output from the powder silo 110 has a micron-sized particle size, the solid-gas mixing ratio of the system is greater than 10; when the material has a particle size of more than a millimeter, the solid-gas mixing ratio of the system is less than 3). The gas-solid two-phase flow is conveyed through the pipe 160, which has a 1-3mm thick wear-resistant ceramic coating on its inner wall. The flow velocity of the gas-solid two-phase flow in the pipe 160 deviates from the air velocity at the nozzle of the dedicated burner 170 (not less than 25m / s) by no more than ±2m / s. Finally, the gas-solid two-phase flow enters the dedicated burner 170, where the dedicated burner 170 completes the energy conversion of the biomass material on the boiler body 180, realizing the entire biomass production pretreatment and pneumatic conveying process.

[0031] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A pretreatment method for biomass production, characterized in that, It includes a crushing section and a bypass channel. The crushing section is connected to a coarse crushing section via a first conveying mechanism. The coarse crushing section is connected to a drying section via a second conveying mechanism. The drying section is connected to a fine crushing section via a third conveying mechanism. A fourth conveying mechanism is installed at the discharge end of the fine crushing section. The bypass channel is connected to the first to fourth bypass distribution mechanisms and is respectively connected to the first to fourth conveying mechanisms. The coarse crushing section includes an anti-clogging variable frequency hopper, a destoner, an iron remover, and a coarse crusher.

2. A pneumatic conveying system, characterized in that, The system includes the biomass production pretreatment and powder silo as described in claim 1. One end of the fourth conveying mechanism is connected to the feed end of the powder silo. The discharge end of the powder silo is connected to the feed end of a rotary closed-air unloader via a belt conveyor. The discharge end of the rotary closed-air unloader is connected to a solid-gas mixer. A Roots blower is fixedly installed at the air inlet of the solid-gas mixer. The discharge end of the solid-gas mixer is connected to the feed end of a special burner via a pipeline. The discharge end of the special burner is adapted to connect to a boiler.

3. The pneumatic conveying system according to claim 2, characterized in that, The pressure head range of the Roots blower is 20-98 kPa.

4. A pneumatic conveying system according to claim 2, characterized in that, The rotary air-sealed unloader is equipped with sealing blades inside, and the gap between the sealing blades and the inner wall of the housing is less than 0.5 mm.

5. A pneumatic conveying system according to claim 2, characterized in that, The solid-gas mixer is equipped with a spiral guide plate inside.

6. A pneumatic conveying system according to claim 2, characterized in that, The inner wall of the pipe is coated with a wear-resistant ceramic coating.

7. A pneumatic conveying system according to claim 2, characterized in that, The nozzle velocity of the special burner is not less than 25 m / s, and the flow velocity of the gas-solid two-phase flow in the pipeline deviates from the nozzle velocity of the special burner by no more than ±2 m / s.

8. A pneumatic conveying system according to claim 2, characterized in that, A pellet mill is installed at the bottom of the powder silo via a feed pipe, and a filter screen is installed at the top of the feed pipe.

9. A pneumatic conveying system according to claim 8, characterized in that, A dust collector is installed at the top exhaust port of the pellet mill via a dust removal pipe, and a fan is installed at the exhaust end of the dust collector.

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