Biomass powder pneumatic conveying system and its commissioning and decommissioning methods

Abstract

The present application belongs to the field of coal-biomass combined power generation technology, and discloses a biomass powder pneumatic conveying system and its commissioning method and shutdown method. The biomass powder pneumatic conveying system comprises a pneumatic conveying part, a feeding device, a gas-solid mixer, a gas-solid separation assembly and a circulating device. The inlet of the pneumatic conveying part is communicated with the external atmosphere. The feeding device is used for feeding biomass powder. The gas inlet of the gas-solid mixer is communicated with the air outlet of the pneumatic conveying part, and the solid inlet of the gas-solid mixer is communicated with the discharge port of the feeding device. The inlet of the gas-solid separation assembly is communicated with the outlet of the gas-solid mixer, and the gas-solid separation assembly is used for carrying out gas-solid separation on the gas flow carrying biomass powder. The inlet of the circulating device is communicated with the outlet section of the gas-solid separation assembly, the solid outlet of the circulating device is communicated with the feeding port of the feeding device, and the gas outlet of the circulating device is communicated with the inlet section of the pneumatic conveying part. The biomass powder can be conveyed at high concentration, high power and strong stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal-fired coupling biomass power generation, and particularly relates to a biomass powder pneumatic conveying system and a starting method and a stopping method thereof. BACKGROUND

[0002] With the increasing demand for energy in society, the utilization rate of resources such as biomass is also increasing. At present, biomass direct combustion power generation has the disadvantages of high investment and low efficiency, and therefore, coal-fired coupling biomass power generation is usually adopted, which is a technology of fully utilizing the value of existing coal power assets and energy utilization of biomass. The direct blending of biomass in a coal-fired boiler has the advantages of high consumption level, high cycle efficiency, low construction and operation cost, and is widely used in biomass coupling power generation projects. The biomass powder conveying method is the key to the direct blending of biomass in a coal-fired boiler, which determines the scale, stability and energy consumption level of biomass treatment.

[0003] Due to the small bulk density and poor flowability of biomass powder, and the relatively long distance between the biomass crushing area and the boiler combustion area, the existing biomass powder conveying method generally adopts pneumatic conveying to convey the crushed biomass powder. However, the biomass powder pneumatic conveying faces the problems of low powder concentration, small conveying capacity and poor stability, which is difficult to meet the demand of large-scale and large-proportion blending of biomass in a coal-fired boiler. Moreover, the low-concentration pneumatic conveying of biomass powder will lead to a decrease in combustion performance in the furnace and a significant increase in cold air into the furnace, which is not conducive to the ignition / burning in the furnace and the control of NOx emission, and increases the heat loss of flue gas, thereby reducing the thermal efficiency of the boiler.

[0004] Therefore, there is an urgent need for a biomass powder pneumatic conveying system and a starting method and a stopping method thereof to solve the above technical problems. SUMMARY

[0005] An object of the present application is to provide a biomass powder pneumatic conveying system capable of realizing high-concentration, large-capacity and strong-stability conveying of biomass powder.

[0006] To achieve the above object, the present application adopts the following technical solutions:

[0007] The biomass powder pneumatic conveying system comprises:

[0008] a pneumatic conveying member, an inlet of the pneumatic conveying member being communicated with the outside atmosphere, the pneumatic conveying member being used for supplying air with a preset pressure to form an air flow with the preset pressure for conveying the biomass powder;

[0009] a feeding device, the feeding device being used for supplying the biomass powder;

[0010] a gas-solid mixer, a gas inlet of the gas-solid mixer being communicated with an air outlet of the pneumatic conveying device, a solid inlet of the gas-solid mixer being communicated with a material outlet of the feeding device, the gas-solid mixer being used for mixing the biomass powder and air;

[0011] a gas-solid separation assembly, an inlet of the gas-solid separation assembly being communicated with an outlet of the gas-solid mixer, the gas-solid separation assembly being used for separating the gas flow carrying the biomass powder into a dense phase gas flow and a dilute phase gas flow;

[0012] a circulating device, an inlet of the circulating device being communicated with an outlet section of the gas-solid separation assembly, a solid outlet of the circulating device being communicated with a feeding port of the feeding device, and a gas outlet of the circulating device being communicated with an inlet section of the pneumatic conveying device, so as to suck the dilute phase gas flow and recycle it.

[0013] Optionally, the gas-solid separation assembly comprises a first main pipeline, an inlet of the first main pipeline being communicated with the outlet of the gas-solid mixer, and an outlet of the first main pipeline being used for supplying the biomass powder outside;

[0014] the first main pipeline is provided with an arc-shaped bend, and the arc-shaped bend is used for performing first-stage gas-solid separation on the gas flow carrying the biomass powder;

[0015] the first main pipeline is further provided with a gas-solid separation block, and along a flow direction of the gas flow in the first main pipeline, the gas-solid separation block is arranged downstream of the arc-shaped bend, so as to perform second-stage gas-solid separation on the gas flow carrying the biomass powder, and an inlet of the circulating device is communicated downstream of the gas-solid separation block, so as to suck the dilute phase gas flow.

[0016] Optionally, the circulating device comprises:

[0017] a first circulating pipeline, an inlet of the first circulating pipeline being communicated with the outlet section of the gas-solid separation assembly;

[0018] a cyclone separator, an inlet of the cyclone separator being communicated with an outlet of the first circulating pipeline, and the cyclone separator having a gas outlet and a solid outlet;

[0019] a second circulating pipeline, an inlet of the second circulating pipeline being communicated with the gas outlet of the cyclone separator, and an outlet of the second circulating pipeline being communicated with the inlet section of the pneumatic conveying device;

[0020] a return pipeline, an inlet of the return pipeline being communicated with the solid outlet of the cyclone separator, and an outlet of the return pipeline being communicated with the feeding port of the feeding device.

[0021] Optionally, the feeding device comprises:

[0022] a powder bin, an inlet of the powder bin being communicated with the feeding device;

[0023] a first screw conveyor, an inlet of the first screw conveyor being communicated with the powder bin, and the first screw conveyor being horizontally arranged, the first screw conveyor being used for screw conveying of the biomass powder;

[0024] a second screw conveyor, an inlet of the second screw conveyor being communicated with an outlet of the first screw conveyor, an outlet of the second screw conveyor being communicated with a solid inlet of the gas-solid mixer, and the second screw conveyor being obliquely arranged, the second screw conveyor being used for screw conveying of the biomass powder.

[0025] Optionally, an outlet section of the pneumatic conveying member is provided with a check structure, the check structure being used for preventing the biomass powder in the gas-solid mixer from flowing back to the pneumatic conveying member; and / or,

[0026] an outlet section of the feeding device is provided with a first air lock, the first air lock being used for preventing the gas flow in the gas-solid mixer from flowing back into the feeding device; and / or,

[0027] a solid outlet section of the circulating device is provided with a second air lock, the second air lock being used for preventing the gas flow in the circulating device from flowing into the feeding device.

[0028] Optionally, an inlet section of the pneumatic conveying member is provided with a first regulating valve, the first regulating valve being used for regulating the amount of external air entering; and / or,

[0029] an outlet section of the circulating device is provided with a second regulating valve, the second regulating valve being used for regulating the amount of air circulating.

[0030] Optionally, an outlet section of the pneumatic conveying member is provided with a cyclone vane, the cyclone vane being used for increasing the turbulence degree of the conveying air.

[0031] Optionally, the gas-solid mixer is a Venturi structure.

[0032] Still another object of the present application is to provide a biomass powder pneumatic conveying system commissioning method, which can realize high-concentration, high-power and strong-stability conveying of the biomass powder.

[0033] To achieve the above objects, the present application adopts the following technical solutions:

[0034] The biomass powder pneumatic conveying system commissioning method uses the biomass powder pneumatic conveying system, and comprises the following steps:

[0035] S110, close the first regulating valve between the pneumatic conveying device and the outside atmosphere and the second regulating valve between the circulating device and the pneumatic conveying device, and start the pneumatic conveying device;

[0036] S120, open the first regulating valve and adjust the conveying pressure of the pneumatic conveying device;

[0037] S130, sequentially start the second screw conveyor, the first air lock and the first screw conveyor of the feeding device to start the feeding device;

[0038] S140, start the second air lock of the solid outlet of the circulating device and open the second regulating valve to start the circulating device;

[0039] S150, adjust the opening degree of the first regulating valve and the second regulating valve to change the circulating air ratio;

[0040] S160, put the biomass powder into the feeding port of the feeding device and adjust the running frequency of the first screw conveyor and the second screw conveyor to change the feeding amount of the biomass powder.

[0041] Still another object of the present application is to provide a biomass powder pneumatic conveying system shutdown method, which can realize high-concentration, high-power and strong-stability conveying of biomass powder.

[0042] To achieve the above object, the present application adopts the following technical scheme:

[0043] The biomass powder pneumatic conveying system shutdown method uses the biomass powder pneumatic conveying system, and comprises the following steps:

[0044] S210, stop putting the biomass powder into the feeding device and observe the position of the biomass powder in the powder bin of the feeding device;

[0045] S220, after the biomass powder in the powder bin is consumed and a first preset time is maintained, sequentially stop the first screw conveyor, the first air lock and the second screw conveyor to close the feeding device;

[0046] S230, close the second regulating valve and stop the second air lock to close the circulating device;

[0047] S240, maintain the pneumatic conveying device blowing for a second preset time, stop the pneumatic conveying device and close the first regulating valve.

[0048] The present application has the following advantages:

[0049] This invention provides a pneumatic conveying system for biomass powder, along with its commissioning and shutdown methods. By incorporating a gas-solid separation component, resistance is created to the airflow carrying biomass powder, impacting the airflow and achieving gas-solid mixing and separation. This results in a dense phase airflow and a dilute phase airflow. The dense phase airflow is used for output, increasing the concentration, conveying capacity, and stability of the biomass powder in the output airflow of the pneumatic conveying system. This improves the ignition / combustion performance of biomass and the stable combustion capability of the boiler, reducing emissions of pollutants such as NOx. Simultaneously, it reduces the amount of air entering the boiler, lowering boiler flue gas heat loss and improving boiler thermal efficiency. Furthermore, the dilute phase airflow is recycled through a circulation device, increasing the utilization rate of the pneumatic conveying system and contributing to energy conservation and emission reduction. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the working principle of the pneumatic conveying system for biomass powder provided in a specific embodiment of the present invention.

[0051] In the picture:

[0052] 10. Pneumatic conveying components; 11. High-pressure blower; 12. Second main pipeline; 13. Third main pipeline; 14. Swirl blades;

[0053] 20. Feeding device; 21. Powder silo; 22. First screw conveyor; 23. Second screw conveyor; 24. Conical structure;

[0054] 30. Gas-solid mixer;

[0055] 40. Gas-solid separation component; 41. First main pipeline; 42. Arc-shaped bend; 43. Gas-solid separation block;

[0056] 50. Circulation device; 51. First circulation pipeline; 52. Cyclone separator; 53. Second circulation pipeline; 54. Return pipe;

[0057] 60. Check valve; 70. First airlock; 80. Second airlock; 90. First regulating valve; 100. Second regulating valve. Detailed Implementation

[0058] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0059] In the description of the present application, unless otherwise explicitly specified and limited, the terms "connected", "linked", "fixed" should be understood broadly, for example, can be fixedly connected, can be detachably connected, or integrated; can be directly connected, or indirectly connected through an intermediate medium; can be internal connection of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0060] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the first feature "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature "under", "below" and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0061] In the description of the present embodiment, the terms "up", "down", "left", "right", and other orientation or position relationships are based on the orientation or position relationship shown in the drawings, and are only for the convenience of description and simplification of operation, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0062] The following refers to Figure 1 The present application provides a biomass powder pneumatic conveying system and its commissioning method and shutdown method.

[0063] It should be noted that, Figure 1 The arrow direction of the biomass powder pneumatic conveying system in the present embodiment is the flow direction of the gas flow conveying the biomass powder.

[0064] The present embodiment provides a biomass powder pneumatic conveying system, which conveys biomass powder by gas force.

[0065] Please refer to Figure 1, specifically, the biomass powder pneumatic conveying system comprises a pneumatic conveying part 10, a feeding device 20, a gas-solid mixer 30, a gas-solid separation assembly 40 and a circulating device 50. The inlet of the pneumatic conveying part 10 is communicated with the outside atmosphere, the pneumatic conveying part 10 is used for supplying air with a preset pressure to form an air flow with a preset pressure for conveying the biomass powder; the feeding device 20 is used for supplying the biomass powder; the gas inlet of the gas-solid mixer 30 is communicated with the air outlet of the pneumatic conveying part 10, the solid inlet of the gas-solid mixer 30 is communicated with the discharge port of the feeding device 20, the gas-solid mixer 30 is used for mixing the biomass powder and the air; the inlet of the gas-solid separation assembly 40 is communicated with the outlet of the gas-solid mixer 30, the gas-solid separation assembly 40 is used for separating the air flow carrying the biomass powder to divide the air flow carrying the biomass powder into a dense phase air flow and a dilute phase air flow; the inlet of the circulating device 50 is communicated with the outlet section of the gas-solid separation assembly 40, the solid outlet of the circulating device 50 is communicated with the feeding port of the feeding device 20, and the gas outlet of the circulating device 50 is communicated with the inlet section of the pneumatic conveying part 10, so as to suck the dilute phase air flow and recycle it.

[0066] In use, the air with the preset pressure output by the pneumatic conveying part 10 forms an air flow, the air flow flows into the gas-solid mixer 30 to mix with the biomass powder, and carries the biomass powder to the gas-solid separation assembly 40 to form the dense phase air flow and the dilute phase air flow, the dense phase air flow flows out of the output port to increase the concentration of the biomass powder in the output air flow and reduce the output of the air; and the dilute phase air flow is returned to the corresponding pneumatic conveying part 10 and feeding device 20 through the circulating device 50 to realize recycling.

[0067] The biomass powder pneumatic conveying system in the embodiment forms a resistance to the air flow carrying the biomass powder to impact the air flow, realizes gas-solid mixing and separation, and forms the dense phase air flow and the dilute phase air flow, the dense phase air flow is used for output, the concentration, conveying amount and stability of the biomass powder in the air flow output by the biomass powder pneumatic conveying system are improved, the ignition / burning performance of the biomass and the stable combustion ability of the boiler are improved, the emission of pollutants such as NOx is reduced, the amount of air entering the boiler is reduced, the flue gas heat loss of the boiler is reduced, and the thermal efficiency of the boiler is improved. Moreover, the dilute phase air flow is recycled through the circulating device 50, the utilization rate of the biomass powder pneumatic conveying system is improved, and energy saving and emission reduction are facilitated.

[0068] It should be noted that the above-mentioned preset pressure is a required pressure, that is, the air flow velocity required by the biomass powder pneumatic conveying system is set, which is not limited here.

[0069] Please continue to refer to Figure 1In the embodiment, the pneumatic conveying device 10 comprises a high-pressure fan 11, a second main pipeline 12 and a third main pipeline 13, the inlet of the second main pipeline 12 is communicated with the external atmosphere, the inlet of the high-pressure fan 11 is communicated with the second main pipeline 12, the outlet of the high-pressure fan 11 is communicated with the inlet of the third main pipeline 13, and the outlet of the third main pipeline 13 is communicated with the gas-solid mixer 30. In use, the high-pressure fan 11 drives the second main pipeline 12 to suck air from the external atmosphere and convey the air to the third main pipeline 13, so that the third main pipeline 13 circulates air with a preset pressure.

[0070] Specifically, the high-pressure fan 11 is configured with a variable-frequency and explosion-proof motor to change the operating frequency of the high-pressure fan 11 and has an explosion-proof function to improve safety.

[0071] Optionally, the pressure head of the high-pressure fan 11 has a pressure range of 10 kPa to 70 kPa to meet the conveying of biomass powder of common boilers and other structures.

[0072] Further, the inlet section of the pneumatic conveying device 10 is provided with a first regulating valve 90, and specifically, the first regulating valve 90 is arranged on the second main pipeline 12 to regulate the amount of external air entering and adjust the supply amount of airflow.

[0073] Optionally, the first regulating valve 90 is selected from an electric explosion-proof valve or a pneumatic explosion-proof valve, that is, the second main pipeline 12 can be opened, closed or regulated, which is not specifically limited here.

[0074] Further, the outlet section of the pneumatic conveying device 10 is provided with a check structure 60, and specifically, the check structure 60 is arranged on the third main pipeline 13, and the check structure 60 is used to prevent the biomass powder in the gas-solid mixer 30 from flowing back to the pneumatic conveying device 10, thereby avoiding the backflow of airflow when the pressure of the boiler and other output structures is too large, thereby avoiding the damage of the structures such as the high-pressure fan 11 in the pneumatic conveying device 10, and improving the use reliability and safety of the structures in the pneumatic conveying device 10.

[0075] Further, the outlet section of the pneumatic conveying device 10 is provided with a cyclone blade 14, and specifically, the cyclone blade 14 is arranged on the third main pipeline 13 to increase the turbulence degree of the conveying air, thereby strengthening the mixing of the biomass powder and air in the gas-solid mixer 30 and preventing the accumulation of the biomass powder.

[0076] In the embodiment, the feeding device 20 comprises a powder bin 21, a first screw conveyor 22 and a second screw conveyor 23, the inlet of the powder bin 21 is communicated with the feeding device; the inlet of the first screw conveyor 22 is communicated with the powder bin 21, and the first screw conveyor 22 is horizontally arranged and used for screw conveying of the biomass powder; the inlet of the second screw conveyor 23 is communicated with the outlet of the first screw conveyor 22, the outlet of the second screw conveyor 23 is communicated with the solid inlet of the gas-solid mixer 30, and the second screw conveyor 23 is obliquely arranged and used for screw conveying of the biomass powder. In use, the operator can put the biomass powder into the powder bin 21, and the biomass powder is sequentially screw mixed by the two screw conveyors through the outlet of the powder bin 21, so that the uniformity of the mixed biomass powder is improved and the biomass powder is conveyed, thereby realizing more uniform conveying of the biomass powder. Moreover, the first screw conveyor 22 is horizontally arranged, and the second screw conveyor 23 is obliquely arranged, so that the accumulation and blockage of the biomass powder are greatly reduced, and the conveying effect of the biomass powder is improved.

[0077] Specifically, the powder bin 21 is in an inverted trapezoidal structure, and the top opening is large as a feeding port to realize external feeding or feeding of the recycled material of the circulating device 50.

[0078] Optionally, the powder bin 21 is provided with a cone structure 24 to prevent arching of the biomass powder and improve the flow effect of the biomass powder in the powder bin 21.

[0079] Specifically, the side wall of the discharge port of the first screw conveyor 22 is an inclined wall to prevent accumulation and blockage of the biomass powder, so that the biomass powder can be completely fed into the second screw conveyor 23.

[0080] Optionally, the first screw conveyor 22 and the second screw conveyor 23 are both provided with a variable-frequency explosion-proof motor to dynamically and accurately adjust the feeding amount of the biomass powder.

[0081] Moreover, the first screw conveyor 22 and the second screw conveyor 23 adopt a shaftless screw conveying structure, which greatly improves the anti-winding performance of the screw conveying and avoids blockage.

[0082] Further, the discharge section of the feeding device 20 is provided with a first air lock 70 for preventing the airflow in the gas-solid mixer 30 from carrying the powder back into the feeding device 20. Specifically, the first air lock 70 is arranged between the first screw conveyor 22 and the second screw conveyor 23 to prevent the airflow from carrying the powder back into the feeding device 20.

[0083] In the embodiment, the gas-solid mixer 30 is a Venturi structure, i.e. the diameter of the throat is smaller than the diameter of the body, so that the air flow rate at the throat is increased, the mixing effect of the biomass powder and the air is improved, the static pressure at the throat is reduced, the biomass powder is prevented from returning, and the use reliability of the gas-solid mixer 30 is improved.

[0084] Optionally, the air flow rate at the throat of the gas-solid mixer 30 is selected to be 50 m / s to 100 m / s, so that the mixing effect of the gas-solid is improved and the biomass powder is prevented from returning.

[0085] In the embodiment, the gas-solid separation assembly 40 includes a first main pipeline 41, the inlet of the first main pipeline 41 is communicated with the outlet of the gas-solid mixer 30, and the outlet of the first main pipeline 41 is used to supply the biomass powder externally; the first main pipeline 41 is provided with an arc-shaped bend 42, the arc-shaped bend 42 is used to perform the first-stage gas-solid separation on the gas flow carrying the biomass powder; the first main pipeline 41 is further provided with a gas-solid separation block 43, along the flow direction of the gas flow in the first main pipeline 41, the gas-solid separation block 43 is arranged downstream of the arc-shaped bend 42 to perform the second-stage gas-solid separation on the gas flow carrying the biomass powder; and the inlet of the circulating device 50 is communicated with the downstream of the gas-solid separation block 43 to suck the dilute-phase gas flow. In this way, when the gas flow carrying the biomass powder flows through the first main pipeline 41, the gas flow is subjected to the gas-solid separation twice by the pipe wall of the arc-shaped bend 42 and the gas-solid separation block 43, so that the concentration and separation of the biomass powder in the gas flow are realized, and the dense-phase gas flow and the dilute-phase gas flow are separated. Moreover, the arc-shaped bend 42, the gas-solid separation block 43 and the circulating device 50 are sequentially arranged along the flow direction of the gas flow in the first main pipeline 41, so that the dense-phase gas flow and the dilute-phase gas flow are directly separated and discharged after the gas flow carrying the biomass powder is separated twice, and the gas flow is prevented from being mixed again.

[0086] Specifically, the gas flow rate in the first main pipeline 41 is 14 m / s to 30 m / s, so that the flow of the gas flow in the first main pipeline 41 is realized, the conveying, separation and recycling of the biomass powder are ensured, and the deposition is avoided.

[0087] Optionally, the arc-shaped bend 42 is a large-curvature-radius anti-wear elbow, which can reduce the frictional resistance during the flow, has good wear resistance, and is good for the separation of the dense-phase and the dilute-phase in the gas flow.

[0088] Further optionally, the gas-solid separation block 43 is a wear-resistant part, and the cross-sectional area of the gas-solid separation block 43 accounts for 1 / 4 to 1 / 3 of the cross-sectional area of the pipeline. In this way, the separation of the gas and the solid is better realized, and the dense-phase gas flow and the dilute-phase are separated.

[0089] Optionally, the gas-solid separation block 43 is trapezoidal, arc-shaped, triangular, etc., which is not limited here. For example, the gas-solid separation block 43 is trapezoidal, and the separation effect is better.

[0090] In the embodiment, the circulating device 50 comprises a first circulating pipeline 51, a cyclone separator 52, a second circulating pipeline 53, and a return pipeline 54. The inlet of the first circulating pipeline 51 is communicated with the outlet section of the gas-solid separation assembly 40. The inlet of the cyclone separator 52 is communicated with the outlet of the first circulating pipeline 51, and the cyclone separator 52 has a gas outlet and a solid outlet. The inlet of the second circulating pipeline 53 is communicated with the gas outlet of the cyclone separator 52, and the outlet of the second circulating pipeline 53 is communicated with the inlet section of the pneumatic conveying device 10, i.e., the second main pipeline 12. The inlet of the return pipeline 54 is communicated with the solid outlet of the cyclone separator 52, and the outlet of the return pipeline 54 is communicated with the feeding port of the feeding device 20, i.e., the feeding port of the powder bin 21. The dilute phase gas flow enters the cyclone separator 52 through the first circulating pipeline 51 for gas-solid separation. The residual biomass powder flows into the return pipeline 54 through the solid outlet of the cyclone separator 52 and flows to the feeding device 20 for secondary use. The residual air flows into the second circulating pipeline 53 through the gas outlet of the cyclone separator 52 and flows back to the inlet section of the pneumatic conveying device 10 for secondary use.

[0091] Optionally, the air flow rate in the first circulating pipeline 51 is 10 m / s to 30 m / s, so that the dilute phase gas flow can be inhaled and conveyed.

[0092] Further, the solid outlet section of the circulating device 50 is provided with a second air lock 80, i.e., the second air lock 80 is arranged on the return pipeline 54, and the second air lock 80 is used to prevent the gas flow in the circulating device 50 from flowing into the feeding device 20.

[0093] Further, the outlet section of the circulating device 50 is provided with a second adjusting valve 100 to adjust the air amount for circulation. The first adjusting valve 90 and the second adjusting valve 100 cooperate to adjust the circulating air ratio.

[0094] It should be noted that the circulating air ratio is the percentage of the air amount of the circulating gas flow in the total conveying air amount.

[0095] Optionally, the circulating air ratio is usually selected to be 20% to 60%, so that the biomass powder pneumatic conveying system in common use can be used.

[0096] Optionally, the second adjusting valve 100 is selected to be an electric explosion-proof valve or a pneumatic explosion-proof valve, i.e., the second adjusting valve 100 can be opened, closed, or adjusted in the circulating pipeline, which is not limited here.

[0097] The embodiment also provides a method for putting into operation of the biomass powder pneumatic conveying system, so as to realize the operation of the biomass powder pneumatic conveying system and the conveying of the biomass powder.

[0098] Specifically, the method for putting into operation of the biomass powder pneumatic conveying system comprises the following steps:

[0099] In step S110, the first regulating valve 90 between the pneumatic conveying device 10 and the external atmosphere and the second regulating valve 100 between the circulating device 50 and the pneumatic conveying device 10 are closed, and the pneumatic conveying device 10 is started; that is, whether the system is in the full closed state is checked, and then the pneumatic conveying device 10 is started, so as to avoid the damage caused by the residual biomass powder in the pipeline and other structures to the inlet section of the pneumatic conveying device 10.

[0100] In step S110, the first regulating valve 90 between the pneumatic conveying device 10 and the external atmosphere and the second regulating valve 100 between the circulating device 50 and the pneumatic conveying device 10 are closed, and the pneumatic conveying device 10 is started; that is, whether the system is in the full closed state is checked, and then the pneumatic conveying device 10 is started, so as to avoid the damage caused by the residual biomass powder in the pipeline and other structures to the inlet section of the pneumatic conveying device 10.

[0101] In step S120, the first regulating valve 90 is opened, and the conveying pressure of the pneumatic conveying device 10 is adjusted; that is, the air with the preset pressure is input, so as to form the airflow with the preset pressure, and the pipeline is purged.

[0102] In step S130, the second screw conveyor 23, the first air lock 70 and the first screw conveyor 22 of the feeding device 20 are sequentially put into operation, so as to start the feeding device 20; in this way, the blockage of the two screw conveyors during the conveying process is avoided when the powder bin 21 has the stored material, and the use safety is improved.

[0103] In step S140, the second air lock 80 of the solid outlet of the circulating device 50 is put into operation, and the second regulating valve 100 is opened, so as to start the circulating device 50; that is, the opening and use of the circulating device 50 are realized.

[0104] In step S150, the opening degrees of the first regulating valve 90 and the second regulating valve 100 are adjusted, and the circulating air ratio is changed; the value meeting the use requirement is adjusted, so as to better convey the biomass powder.

[0105] The biomass powder pneumatic conveying system operation method improves the use safety, avoids damage of residual powder to various structures and pipelines in the conveying system, improves the reliability of the biomass powder pneumatic conveying system operation, and can realize high-concentration, high-power and strong-stable conveying of the biomass powder.

[0106] The embodiment also provides a biomass powder pneumatic conveying system shutdown method to realize equipment shutdown and cleaning of the biomass powder pneumatic conveying system.

[0107] Specifically, the biomass powder pneumatic conveying system shutdown method uses the biomass powder pneumatic conveying system according to any one of the above solutions, and the biomass powder pneumatic conveying system shutdown method comprises the following steps.

[0108] In step S210, the biomass powder input to the feeding device 20 is stopped, and the position of the biomass powder in the powder bin 21 of the feeding device 20 is observed; the biomass powder in the feeding device 20 is as much as possible to be completely delivered before shutdown.

[0109] After step S210, step S220 is further included, that is, after the biomass powder in the powder bin 21 is consumed and a first preset time is maintained, the first screw conveyor 22, the first air lock 70 and the second screw conveyor 23 are sequentially shut down to close the feeding device 20; after the biomass powder is completely delivered, the feeding device 20 is sequentially shut down in the reverse order of the opening order to avoid occurrence of biomass powder residue and material blocking.

[0110] After step S220, step S230 is further included, that is, the second regulating valve 100 is closed, the second air lock 80 is shut down to close the circulating device 50; and the biomass powder in the pipeline of the conveying system behind the feeding device 20 is also gradually emptied, so that the circulating device 50 is also purged by the airflow, thereby the circulating device 50 can be closed.

[0111] After step S230, step S240 is further included, that is, the biomass powder pneumatic conveying member 10 is purged for a second preset time, the biomass powder pneumatic conveying member 10 is shut down, and the first regulating valve 90 is closed. The main pipeline of the conveying system is purged to realize cleaning of the conveying system, and residual powder is avoided, and the material return in the boiler is also avoided.

[0112] The biomass powder pneumatic conveying system operation method realizes shutdown and cleaning of the conveying system, improves the use safety, avoids damage of residual powder to various structures and pipelines in the conveying system, and improves the reliability of the biomass powder pneumatic conveying system operation.

[0113] Obviously, the above embodiments of the present application are merely exemplary but not intended to limit the embodiments of the present application. Various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the scope of the present application. It is not necessary or possible to enumerate all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A biomass powder pneumatic conveying system, characterized by, The utility model relates to a biomass powder pneumatic conveying device, comprising: a pneumatic conveying part (10), an inlet of the pneumatic conveying part (10) being communicated with the outside atmosphere, the pneumatic conveying part (10) being used for supplying air with a preset pressure to form a gas flow with a preset pressure to convey biomass powder; a feeding device (20), the feeding device (20) being used for supplying biomass powder; a gas-solid mixer (30), a gas inlet of the gas-solid mixer (30) being communicated with an air outlet of the pneumatic conveying part (10), a solid inlet of the gas-solid mixer (30) being communicated with a discharge port of the feeding device (20), the gas-solid mixer (30) being used for mixing biomass powder and air; a gas-solid separation assembly (40), an inlet of the gas-solid separation assembly (40) being communicated with an outlet of the gas-solid mixer (30), the gas-solid separation assembly (40) being used for carrying out gas-solid separation on a gas flow carrying biomass powder to divide the gas flow carrying biomass powder into a dense phase gas flow and a dilute phase gas flow; a circulating device (50), an inlet of the circulating device (50) being communicated with an outlet section of the gas-solid separation assembly (40), a solid outlet of the circulating device (50) being communicated with a feeding port of the feeding device (20), a gas outlet of the circulating device (50) being communicated with an inlet section of the pneumatic conveying part (10) to suck in and recycle the dilute phase gas flow; the circulating device (50) comprising: a first circulating pipeline (51), an inlet of the first circulating pipeline (51) being communicated with the outlet section of the gas-solid separation assembly (40); a cyclone separator (52), an inlet of the cyclone separator (52) being communicated with an outlet of the first circulating pipeline (51), the cyclone separator (52) having a gas outlet and a solid outlet; a second circulating pipeline (53), an inlet of the second circulating pipeline (53) being communicated with the gas outlet of the cyclone separator (52), an outlet of the second circulating pipeline (53) being communicated with the inlet section of the pneumatic conveying part (10); a back feeding pipe (54), an inlet of the back feeding pipe (54) being communicated with the solid outlet of the cyclone separator (52), an outlet of the back feeding pipe (54) being communicated with the feeding port of the feeding device (20).

2. The biomass powder pneumatic conveying system according to claim 1, wherein, the gas-solid separation assembly (40) comprising a first main pipeline (41), an inlet of the first main pipeline (41) being communicated with the outlet of the gas-solid mixer (30), an outlet of the first main pipeline (41) being used for externally supplying biomass powder; the first main pipeline (41) being provided with an arc-shaped bend (42), the arc-shaped bend (42) being used for carrying out first-stage gas-solid separation on the gas flow carrying biomass powder; the first main pipeline (41) further being provided with a gas-solid separation block (43), along the flow direction of the gas flow in the first main pipeline (41), the gas-solid separation block (43) being arranged downstream of the arc-shaped bend (42) to carry out second-stage gas-solid separation on the gas flow carrying biomass powder; an inlet of the circulating device (50) being communicated downstream of the gas-solid separation block (43) to suck in the dilute phase gas flow.

3. The biomass powder pneumatic conveying system according to claim 1, wherein, The feeding device (20) comprises: a powder bin (21), an inlet of the powder bin (21) being communicated with the feeding device; a first screw conveyor (22), an inlet of the first screw conveyor (22) being communicated with the powder bin (21), and the first screw conveyor (22) being horizontally arranged, the first screw conveyor (22) being used for screw conveying of the biomass powder; a second screw conveyor (23), an inlet of the second screw conveyor (23) being communicated with an outlet of the first screw conveyor (22), an outlet of the second screw conveyor (23) being communicated with a solid inlet of the gas-solid mixer (30), and the second screw conveyor (23) being obliquely arranged, the second screw conveyor (23) being used for screw conveying of the biomass powder.

4. The biomass powder pneumatic conveying system according to claim 1, wherein: an outlet section of the pneumatic conveying member (10) is provided with a check structure (60), the check structure (60) being used for preventing the biomass powder in the gas-solid mixer (30) from flowing back to the pneumatic conveying member (10); and / or, an outlet section of the feeding device (20) is provided with a first air lock (70), the first air lock (70) being used for preventing the powder in the gas-solid mixer (30) from flowing back into the feeding device (20) carried by the gas flow; and / or, a solid outlet section of the circulating device (50) is provided with a second air lock (80), the second air lock (80) being used for preventing the gas flow in the circulating device (50) from flowing into the feeding device (20).

5. The biomass powder pneumatic conveying system according to claim 1, wherein: an inlet section of the pneumatic conveying member (10) is provided with a first regulating valve (90) for adjusting the amount of external air entering; and / or, an outlet section of the circulating device (50) is provided with a second regulating valve (100) for adjusting the amount of air circulating.

6. The biomass powder pneumatic conveying system according to claim 1, wherein, An outlet section of the pneumatic conveying member (10) is provided with a cyclone vane (14) for increasing the turbulence degree of the conveying air.

7. The biomass powder pneumatic conveying system according to claim 1, wherein The gas-solid mixer (30) is of a Venturi structure.

8. A method of putting into operation a biomass powder pneumatic conveying system, characterized by, The biomass powder pneumatic conveying system according to any one of claims 1-7 is put into operation by the following steps: S110, closing the first regulating valve (90) between the pneumatic conveying member (10) and the external atmosphere and the second regulating valve (100) between the circulating device (50) and the pneumatic conveying member (10), and starting the pneumatic conveying member (10); S120, opening the first regulating valve (90) and adjusting the conveying pressure of the pneumatic conveying member (10); S130, sequentially putting the second screw conveyor (23), the first air lock (70) and the first screw conveyor (22) of the feeding device (20) into operation to start the feeding device (20); S140, putting the second air lock (80) of the solid outlet of the circulating device (50) into operation, and opening the second regulating valve (100) to start the circulating device (50); S150, sequentially putting the first air lock (70) of the feeding device (20), the second air lock (80) of the solid outlet of the circulating device (50) and the first regulating valve (90) into operation to start the biomass powder pneumatic conveying system. S150, adjusting the opening degree of the first regulating valve (90) and the second regulating valve (100) to change the circulating air ratio; S160, feeding the biomass powder into the feeding inlet of the feeding device (20), and adjusting the operating frequency of the first screw conveyor (22) and the second screw conveyor (23) to change the feeding amount of the biomass powder.

9. Biomass powder pneumatic conveying system shutdown method, characterized by, The biomass powder pneumatic conveying system according to any one of claims 1-7, wherein the shutdown method of the biomass powder pneumatic conveying system comprises the following steps: S210, stopping the feeding of the biomass powder into the feeding device (20), and observing the position of the biomass powder in the powder bin (21) of the feeding device (20); S220, after the biomass powder in the powder bin (21) is consumed and a first preset time is maintained, sequentially shutting down the first screw conveyor (22), the first air lock (70) and the second screw conveyor (23) to close the feeding device (20); S230, closing the second regulating valve (100) and shutting down the second air lock (80) to close the circulating device (50); S240, maintaining the blowing of the pneumatic conveying part (10) for a second preset time, shutting down the pneumatic conveying part (10), and closing the first regulating valve (90).

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