Uniformly-distributed feeding and discharging powder bin conveying structure, powder conveying method and application

Abstract

The invention relates to the technical field of powder conveying, in particular to a uniformly-distributed feeding and discharging powder bin conveying structure, a powder conveying method and application. The uniform feeding and discharging powder bin conveying structure comprises a bin body, a secondary powder distribution conical component, a multi-point fluidizer pipe opening, a powder collector, a discharging pipeline and a fluidizing disc. Compared with the technical defects that in the prior art, powder caking and unstable flowing are caused by the problems of powder overstocking, agglomeration and accumulation of lower discharging, the situation that powder is scratched by several discharging pipes of side discharging happens occasionally, the mass flow fluctuation of a powder pipeline is large, and the powder pipeline vibrates, the technical defects that in the prior art, the feeding and discharging structure and the fluidization mode are optimized, and the powder pipeline is formed; uniform feeding, dead-corner-free fluidization and stable discharging of powder are achieved, and the strict requirement for powder conveying under the medium-high pressure working condition is met. And meanwhile, the powder conveying method matched with the conveying structure with the evenly-distributed feeding and discharging powder bins is high in adaptability and flexible to operate, and the stability and efficiency of the whole production process are improved.

Description

Technical Field

[0001] This invention relates to the field of powder conveying technology, and in particular to a uniformly distributed powder silo conveying structure, powder conveying method and application. Background Technology

[0002] Powder conveying primarily relies on a gaseous medium to carry powder particles in a fluidized state to achieve the conveying purpose. Especially in the fields of dry powder and biomass powder fluidized bed gasification, the powder must achieve a stable and homogeneous flow state within medium- and high-pressure pipelines, ensuring that the pipelines are free from high-frequency vibration and excessive wear. Currently, the direct vertical drop of powder into the silo from the top of the silo easily leads to powder accumulation under gravity, causing biomass powder particles to easily adhere and clump together, and resulting in poor feed uniformity.

[0003] In existing technologies, powder silo discharge mainly adopts two methods: bottom discharge and side discharge. The powder in the silo is continuously output from the silo in a fluidized state through the process pipe. Bottom discharge increases the device height due to the discharge pipeline and fluidizing airflow device being set at the bottom of the powder silo. In addition, bottom discharge is prone to powder accumulation, agglomeration, and accumulation, leading to powder clumping and unstable flow. Side discharge, on the other hand, has a lower device height because the discharge process pipe is located on the side of the silo, resulting in lower investment compared to bottom discharge. However, current side discharge powder silos share a single fluidizing disc component at the bottom, which can easily cause uneven powder distribution at the discharge pipe, frequent instances of powder competing for powder among several discharge pipes, large fluctuations in the mass flow rate of the powder pipeline, and vibration of the powder pipeline.

[0004] Alternatively, CN223751587U discloses a flow-assisted powder arch-breaking and feeding device, including an arch-breaking and agitating device, a feeding box, a chain drive device, and a drive motor. The feeding box is installed at the discharge flange below the powder silo cone, and the chain drive device and drive motor are installed on the side wall of the feeding box. The arch-breaking and agitating device consists of two main parts: an agitating scraper and a scraper sleeve. The agitating scraper is placed inside the powder silo cone, and the scraper sleeve is placed inside the feeding box and rigidly connected to the agitating scraper. A sleeve drive gear is provided on the lower circumferential outer wall of the scraper sleeve, and the sleeve drive gear is installed inside the groove of the feeding box. Under the combined action of the chain drive device and the drive motor, the scraper sleeve drives the agitating scraper to move circumferentially along the inner wall of the powder silo cone, agitating the material inside the powder silo cone. Although the technical solution designed a spiral curved scraper to address the "powder caking and voids", it did not take into account the unique physical characteristics of biomass powder, such as "high adhesion and easy agglomeration", and still suffers from the technical defect of poor compatibility between the arch breaking and anti-sticking effects.

[0005] Alternatively, CN222433112U discloses a top-discharge feeding tank with a conical fluidized disc structure, relating to a feeding tank in a pneumatic conveying system. It includes a feeding tank body, a material inlet and a material outlet located at the top of the feeding tank body. The material outlet extends to the bottom of the feeding tank body via a set of conveying pipes. A set of fluidized discs, inverted conical shapes, is installed at the bottom of the feeding tank body. The bottom end of the fluidized discs has a circular hole connecting to a conveying gas pipe. The bottom inlet of the conveying pipes extends above the circular hole. A fluidizer is also installed within the opening on the conical surface of the fluidized disc. This technical solution focuses on "improving the efficiency of material entering the conveying pipes" but does not consider the homogeneity requirements of powder conveying under medium- and high-pressure conditions. Its single conveying pipe design cannot meet the stable feeding needs of multiple branches.

[0006] Based on the above-mentioned existing technology, there are still technical problems that urgently need to be solved, such as the large space occupied by the powder silo, uneven discharge, and inability to adapt to the requirements of medium and high pressure powder conveying. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention proposes a uniformly distributed feed and discharge powder silo conveying structure and powder conveying method. By optimizing the feed and discharge structure and fluidization mode, uniform feeding, dead-angle-free fluidization, and stable discharge of powder are achieved, meeting the stringent requirements for powder conveying under medium and high pressure conditions.

[0008] This invention provides a uniformly distributed powder silo conveying structure, including a silo body, a secondary powder distribution conical component, a multi-point fluidizer inlet, a powder collector, a discharge pipeline, and a fluidizing disc;

[0009] The top of the silo is provided with a feed inlet, and a secondary powder distribution cone component is set on the top of the inner side of the silo. The feed inlet is arranged inside the cone component to guide the powder to fall evenly to the middle of the silo. The multi-point fluidizer inlet is located on the lower side of the chamber body and is used to introduce fluidizing gas into the chamber body to eliminate fluidization dead zones. The powder collector is located at the bottom of the silo, and the discharge pipeline corresponds to the powder collector and is arranged at an angle upward to avoid powder grabbing during discharge. The fluidizing disc is located at the bottom of the powder collector, and its upper part is evenly divided into sections according to the number of powder collectors. Each section corresponds to one powder collector, ensuring that each collector receives uniform fluidizing gas.

[0010] Furthermore, the silo is a vertical silo.

[0011] Furthermore, the silo body is made of low alloy steel, the secondary powder distribution cone component and the powder collector are made of stainless steel, and the discharge pipeline is made of duplex steel pipe to adapt to medium and high pressure conditions and the wear resistance requirements of powder conveying.

[0012] Furthermore, the secondary powder distribution cone-shaped component is coaxially arranged with the silo body.

[0013] Furthermore, the multi-point fluidizer inlet introduces fluidizing gas into the silo in a circumferential and tangential flow pattern, which couples with the fluidizing gas generated by the fluidizing plate at the bottom of the silo, ensuring that the powder in the silo is in a fluidized state without dead corners, while solving the problems of powder sticking to the wall and sedimentation.

[0014] Furthermore, the number and opening angle of the fluidizing holes in each zone of the fluidizing plate are consistent, ensuring that the fluidizing gas pressure and flow rate output from each zone are uniform, thereby ensuring that the fluidization state of the powder in each powder collector is consistent, providing a guarantee for stable discharge.

[0015] Furthermore, the secondary powder distribution cone component is fixed to the outer shell of the silo by ribs to ensure its installation stability under medium and high pressure conditions and to prevent displacement due to airflow impact or material compression.

[0016] Furthermore, the structure, volume, and size parameters of the powder collectors are all consistent, ensuring uniform material distribution in each collector and structurally preventing powder snatching between discharge pipelines.

[0017] Furthermore, the number of feed inlets at the top of the silo is at least two, which can be adjusted according to the actual conveying volume requirements. The feed inlets are evenly arranged around the secondary powder distribution cone component to ensure that the powder is evenly dispersed to the middle of the silo after being guided by the cone component.

[0018] Furthermore, the number of feed inlets at the top of the silo is preferably 2-4.

[0019] Furthermore, the cone angle of the secondary powder distribution cone component is between 30-50°, and the distance between its outer circle and the inner wall of the silo is between 50-100mm. This parameter design can ensure the uniform distribution of powder and prevent powder from accumulating between the cone component and the silo wall.

[0020] Furthermore, the number of multi-point fluidizer inlets is at least 6, the angle between the inlet and the outer shell of the silo is between 45-60°, and the radial angle between the inlet and the cross-section of the silo is between 50-60°. The number of layers of multi-point fluidizing gas can be adjusted according to the height of the silo to ensure that the powder at different heights in the lower part of the silo can be effectively fluidized.

[0021] Furthermore, the number of the multi-point fluidizer inlets is preferably 6-8.

[0022] Furthermore, the radial angle between the multi-point fluidizer inlet and the cross-section of the chamber is preferably 60°.

[0023] Furthermore, the upward inclination angle of the discharge pipe is between 60-80°, the bottom of the discharge pipe is parallel to the surface of the fluidizing plate, and the distance between them is between 80-130mm. This inclination angle design is conducive to the smooth flow of fluidized powder, reduces the wear of powder on the pipe wall, reduces the fluctuation of powder density, and reduces the vibration frequency of the discharge pipeline.

[0024] Furthermore, the fluidizing disk is a side-swirling guide fluidizing disk, and the fluidizing disk is provided with several fluidizing channels.

[0025] Furthermore, the angle between the fluidization channel and the central axis of the silo is between 30-60°. This angle design is conducive to generating a swirling fluidized airflow, which again allows the fluidized powder to flow out smoothly.

[0026] Furthermore, the bottom of the chamber is also provided with a fluidizing gas inlet.

[0027] The present invention also provides a powder conveying method, which adopts the above-mentioned uniformly distributed inlet and outlet powder silo conveying structure, and includes the following steps: Step 1, Introduce fluidizing gas: Divide the fluidizing gas into two streams. One stream is introduced from the bottom of the silo, and after passing through each section of the fluidizing plate, it forms a swirling fluidizing gas flow, which is then evenly introduced into the corresponding powder collector. The other stream enters the silo from the multi-point fluidizer pipe on the side of the silo in a circumferential and tangential flow form, and couples with the fluidizing gas at the bottom. Step 2, Powder feeding: The powder is fed in through the feed pipe at the top of the silo. Under the guidance of the secondary powder distribution cone component, the powder is evenly dropped into the middle of the silo to avoid local accumulation and adhesion. Step 3, Powder fluidization: Under the synergistic effect of two streams of fluidizing gas, the powder forms a gas-solid two-phase fluidized material in the silo, and there are no fluidization dead zones in the silo, which effectively prevents the powder from agglomerating. Step 4, Uniform Discharge: Under the impetus of gravity and fluidizing gas, the fluidized material enters the powder collector at the bottom of the silo. With the assistance of the swirling fluidizing gas flow, it flows smoothly out of the silo through the upward-sloping discharge pipeline corresponding to each collector, thus achieving uniform distribution and stable conveying of the powder.

[0028] Furthermore, the fluidizing gas mentioned in step 1 is an inert gas, including but not limited to nitrogen and carbon dioxide.

[0029] Furthermore, in step 1, the two fluidizing gases have different pressures. The fluidizing gas introduced from the bottom of the silo has a pressure 0.2-0.5 MPa higher than the fluidizing gas introduced from the multi-point fluidizer inlet, in order to ensure that the compacted powder at the bottom is fully fluidized.

[0030] Furthermore, in step 1, the multi-point fluidizer inlets on the side of the silo are divided into 2-3 layers according to height. The fluidizing gas pressure at the upper layer inlet is 0.1-0.3 MPa lower than that at the lower layer to avoid excessive disturbance of the powder at the top, which could cause fluctuations in the material surface.

[0031] Furthermore, for biomass powder that is prone to absorbing moisture and clumping, the fluidizing gas mentioned in step 1 is preheated to 50-80℃ (temperature fluctuation ≤ ±2℃) and dried before being introduced into the silo. This not only improves the fluidization effect but also prevents the powder from absorbing moisture and aggravating adhesion.

[0032] Furthermore, if an even number of feed inlets are used in step 2, the feed can be switched diagonally. The feeding time for each set of inlets is 30-45 minutes, and after a 5-minute interval, the feed is switched to another set of inlets. This avoids the accumulation of powder on the top of the secondary powder distribution cone component caused by multiple inlets feeding at the same time.

[0033] Furthermore, in step 2, the feeding rate is adjusted according to the bulk density of the powder, and the dry powder feeding rate is controlled at 50~120 t / (h). Due to the high viscosity of biomass powder, the feeding rate is reduced to 40-100 t / (h) at the pipe opening. (pipe opening), and pause feeding for 5 minutes every 30~45 minutes, in conjunction with side fluidizing gas purging, to prevent secondary powder distribution and powder adhesion to the surface of the conical component.

[0034] Furthermore, in step 2, for powders with severe agglomeration, pretreatment is performed before feeding, i.e., when the particle size after grinding or crushing is ≤250μm, the powder is then fed through the feed pipe to reduce the guiding pressure of the secondary powder distribution cone component.

[0035] Furthermore, in step 3, first turn on the side multi-point fluidizer inlet to supply air and maintain it for 5-8 minutes to allow the surface powder in the bin to initially fluidize; then turn on the bottom fluidizing plate to supply air to prevent the bottom powder from being directly compressed and clumped together, ensuring a smooth transition in the fluidization process.

[0036] Furthermore, in step 3, 4-6 auxiliary purging ports are added at the location where dead corners are easily formed at the connection between the secondary powder distribution cone component and the silo body. These ports are opened synchronously with the side fluidizing gas. The purging gas pressure is 0.3-0.6 MPa higher than that of the side fluidizing gas. Each purging lasts 10-15 seconds, with an interval of 30-40 minutes, to thoroughly remove the powder deposited in the dead corners.

[0037] Furthermore, in step 4, multiple discharge pipelines achieve a continuous discharge mode based on the pressure difference of the powder silo and the fluidization state of the powder. They can be divided into several discharge pipe groups, and each group of discharge pipelines meets the requirements for continuous discharge.

[0038] The present invention also provides a pressurized fluidized coal conveying system, the system comprising the above-mentioned uniformly distributed feed and discharge pulverized coal silo conveying structure.

[0039] The present invention also provides a pressurized fluidized conveying system for biomass powder, the system comprising the above-mentioned uniformly distributed feed and discharge powder silo conveying structure.

[0040] The beneficial effects of the invention are: 1. This invention provides a uniformly distributed feed and discharge powder silo conveying structure, including a silo body, a secondary powder distribution conical component, a multi-point fluidizer inlet, a powder collector, a discharge pipeline, and a fluidizing disc. Compared with the existing technology, which suffers from powder accumulation, agglomeration, and pile-up problems in bottom discharge leading to powder agglomeration and unstable flow, and the side discharge where powder is often contested by several discharge pipes, resulting in large fluctuations in the mass flow rate of the powder pipeline and vibration of the powder pipeline, this invention optimizes the feed and discharge structure and fluidization method to achieve uniform feeding, dead-angle-free fluidization, and stable discharge of powder, meeting the stringent requirements of powder conveying under medium and high pressure conditions.

[0041] 2. The feeding uniformity of the uniformly distributed feed and discharge powder silo conveying structure of the present invention is significantly improved: Through the design of the secondary powder distribution cone component on the top of the silo, the powder is guided to fall evenly to the middle of the silo body, which effectively solves the problems of powder accumulation, adhesion and agglomeration caused by traditional top vertical feeding. At the same time, the bottom cone surface of the secondary distribution structure can also redistribute the fluctuation of the material surface of the fluidized powder, maintain the stability of the material surface, and ensure that the discharge pressure at the bottom of the silo body is consistent. 3. The present invention has a uniformly distributed inlet and outlet powder silo conveying structure with no fluidization dead zone inside the silo: the multi-point fluidizer inlet set laterally at the lower part of the silo body introduces fluidizing gas in the form of circumferential and tangential flow, which forms a coupling effect with the swirling fluidizing gas generated by the fluidizing plate at the bottom of the silo. This not only solves the problem of powder sticking to the wall and sedimentation, but also ensures that the powder inside the silo is in a fluidized state without dead zones, thus avoiding powder agglomeration. 4. The uniformly distributed inlet and outlet powder silo conveying structure of this invention provides stable discharge without "powder grabbing" phenomenon: the powder collectors at the bottom of the silo correspond one-to-one with the discharge pipelines, and the structure, volume, and size parameters of each collector are consistent. The fluidizing gas uniformity of each zone of the fluidizing plate is good, which fundamentally eliminates the "powder grabbing" phenomenon of traditional side-discharge powder silos, ensures the stability of the flow rate and density of powder in each discharge pipeline, and reduces pipeline vibration. 4. The uniformly distributed feed and discharge powder silo conveying structure of this invention is suitable for medium and high pressure conditions: the silo body is made of low alloy steel, the secondary powder distribution cone component and powder collector are made of stainless steel, and the discharge pipeline is made of duplex steel pipe. The connection of each component is stable and the sealing performance is reliable. It can be adapted to medium and high pressure conditions of 2.0-7.0MPa and meet the application requirements of dry powder and biomass powder fluidized bed gasification. 5. The uniformly distributed inlet and outlet powder silo conveying structure of this invention has low equipment investment cost: the inclined upward discharge form can effectively reduce the overall equipment layout height, reduce the space occupied by the equipment, and reduce investment costs compared with the traditional bottom discharge powder silo. 6. The powder conveying method of this invention, adapted to the uniformly distributed feed and discharge powder silo conveying structure, is highly adaptable and flexible in operation: Through the process design of step-by-step fluidization, directional guidance, and precise discharge, this conveying method can flexibly adjust the fluidizing gas pressure, flow rate, and feed rate according to the characteristics of the powder (such as viscosity and particle size) and conveying requirements, adapting to the conveying of various powder materials such as dry powder and biomass powder; at the same time, the process steps are simple, the coordination of each link is strong, no complex manual intervention is required, and automated continuous operation can be achieved, reducing the difficulty of operation and labor costs, and facilitating seamless connection with subsequent gasification, reaction and other process units, improving the stability and efficiency of the overall production process. Attached Figure Description

[0042] Figure 1 This is a cross-sectional view of the uniformly distributed feed and discharge powder silo structure in an embodiment of the present invention; Figure 2 This is a top view of the uniformly distributed feed and discharge fluidized bed structure in an embodiment of the present invention; Figure 3 This is a cross-sectional view of the multi-point fluidizer inlet structure with evenly distributed feed and discharge powder bins in an embodiment of the present invention; Figure 4 This is a cross-sectional view of the powder hopper structure in Comparative Example 1 of the present invention; Figure 5 This is a cross-sectional view of the powder hopper structure in Comparative Example 2 of the present invention; The labels in the diagram are named as follows: 1. Bin body; 101. Feed inlet; 2. Secondary powder distribution conical component; 3. Multi-point fluidizer inlet; 4. Powder collector; 401. Powder collector baffle; 5. Discharge pipeline; 501. Discharge inlet; 6. Fluidizing disc; 7. Fluidizing gas inlet; 8. Vertical bin body; 801. Feed hole; 9. Discharge pipe; 10. Fluidized airflow device. Detailed Implementation

[0043] Example 1 like Figure 1-3 As shown, this embodiment provides a uniformly distributed powder silo conveying structure, including a silo body 1, a secondary powder distribution conical component 2, a multi-point fluidizer inlet 3, a powder collector 4, a discharge pipeline 5, and a fluidizing disc 6; The top of the silo body 1 is provided with a feed inlet 101, and the secondary powder distribution cone component 2 is provided on the top inner side of the silo body 1. The feed inlet 101 is arranged inside the secondary powder distribution cone component 2 to guide the powder to fall evenly to the middle of the silo body 1. The multi-point fluidizer port 3 is located on the lower side of the cylinder of the chamber 1 and is used to introduce fluidizing gas into the chamber 1 to eliminate fluidization dead zones. The powder collector 4 is located at the bottom of the silo 1, and the discharge pipeline 5 corresponds one-to-one with the powder collector 4 and is arranged obliquely upward to avoid powder grabbing during discharge. The fluidizing plate 6 is located at the bottom of the powder collector 4, and its upper part is evenly divided into sections according to the number of powder collectors 4. Each section corresponds to one powder collector 4, ensuring that the powder collector 4 receives uniform fluidizing gas. The bottom of the chamber 1 is also provided with a fluidizing gas inlet 7.

[0044] like Figure 1 As shown, in this embodiment, the silo body 1 is a vertical silo body.

[0045] In this embodiment, the chamber 1 is made of low alloy steel, with a design pressure of 4.0 MPa, a height of 8 m, and an inner diameter of 4 m. In some embodiments, the design pressure can be changed according to the properties of the powder, and the height and inner diameter of the chamber can be changed according to the amount of powder. The secondary powder distribution cone component 2 and the powder collector 4 are made of stainless steel, and the discharge pipeline 5 is made of duplex steel pipe to adapt to medium and high pressure conditions and the wear resistance requirements of powder conveying. This meets the application requirements in the fields of dry powder and biomass powder fluidized bed gasification.

[0046] like Figure 1 As shown, the secondary powder distribution cone component 4 is coaxially arranged with the silo body 1. Through the design of the secondary powder distribution cone component 4 at the top of the silo, the powder is guided to fall evenly to the middle of the silo body 1, effectively solving the problems of powder accumulation, adhesion and agglomeration caused by traditional top vertical feeding. At the same time, the bottom cone surface of the secondary powder distribution cone component 4 can also redistribute the fluctuation of the material surface of the fluidized powder, maintain the stability of the material surface, and ensure that the material pressure at the bottom of the silo body 1 is consistent.

[0047] like Figure 3 As shown, the multi-point fluidizer inlet 3 introduces fluidizing gas into the chamber 1 in a circumferential and tangential flow form, which couples with the fluidizing gas generated by the fluidizing plate 6 at the bottom of the chamber 1 to ensure that the powder in the chamber 1 is in a fluidized state without dead corners, while solving the problems of powder sticking to the wall and sedimentation. The fluidizing disk 6 is a side-swirling guide fluidizing disk, and the fluidizing disk 6 is provided with a plurality of fluidizing holes. The angle between the fluidizing holes and the central axis of the bin 1 is 35°. This angle design is conducive to generating a swirling fluidizing airflow, which again allows the fluidized powder to flow out smoothly. In some embodiments, the angle between the fluidizing holes and the central axis of the bin 1 can be any value between 30° and 60°.

[0048] The fluidizing disk 6 has a consistent number of fluidizing holes and opening angles in each zone, ensuring uniform fluidizing gas pressure and flow rate in each zone. This, in turn, ensures a consistent fluidization state of the powder in each powder collector 4, guaranteeing stable discharge. In this embodiment, the fluidizing disk 6 is divided into four zones, each with 20 fluidizing holes. Each zone corresponds to a separate powder collector 4, ensuring that each powder collector 4 receives a uniform swirling fluidizing airflow.

[0049] The secondary powder distribution cone component 2 is fixed to the outer shell of the silo body 1 by four stainless steel reinforcing plates to ensure its installation stability under medium and high pressure conditions and to avoid displacement due to airflow impact or material compression.

[0050] like Figure 2 As shown, the powder collector 4 has the same structure, volume, and size parameters. It also has an internal powder collector partition 401 that divides the powder collector 4 into four zones, ensuring uniform distribution of the falling material in each powder collector 4 and structurally preventing powder grabbing between discharge pipelines 5. That is, the powder collectors 4 at the bottom of the silo 1 correspond one-to-one with the discharge pipelines 5, and the structure, volume, and size parameters of each collector are consistent. The fluidizing gas uniformity in each zone of the fluidizing disc 6 is good, fundamentally eliminating the "powder grabbing" phenomenon of traditional side-discharge powder silos, ensuring stable flow rate and density of powder in each discharge pipeline 5, and reducing pipeline vibration. In this embodiment, there are four feed inlets 101 at the top of the silo body. The feed inlets 101 are evenly arranged around the secondary powder distribution cone component 2 to ensure that the powder is evenly dispersed to the middle of the silo body 1 after being guided by the secondary powder distribution cone component 2. In some embodiments, the number of feed inlets 101 can be adjusted according to the actual conveying volume requirements.

[0051] like Figure 1 As shown, the cone angle θ1 of the secondary powder distribution cone component 2 is 45°, and the distance L between its outer circle and the inner wall of the silo is 60 nm, which is between 50-100 mm. This parameter design can ensure the uniform distribution of powder and prevent powder from accumulating between the secondary powder distribution cone component 2 and the silo wall. In some embodiments, the cone angle θ1 of the secondary powder distribution cone component 2 is between 30-50°, and the distance L between its outer circle and the inner wall of the silo is between 50-100 mm.

[0052] like Figure 1 and Figure 3As shown, the multi-point fluidizer inlets 3 have 8 ports, arranged in two layers, with each layer having evenly distributed ports 3. The angle between each multi-point fluidizer inlet 3 and the outer shell of the silo is 60°, and the radial angle θ2 with the cross-section of the silo is also 60°, ensuring effective fluidization of powder at different heights in the lower part of the silo. In some embodiments, the number of multi-point fluidizer inlets 3 is at least 6, with the angle between them and the outer shell of the silo being between 45° and 60°, and the radial angle θ2 with the cross-section of the silo being between 50° and 60°. The number of layers of multi-point fluidizer inlets 3 can be adjusted according to the height of the silo, but is at least 1 layer.

[0053] like Figure 1 As shown, the upward inclination angle θ3 of the discharge port 501 of the discharge pipeline 5 is 70°, the bottom of the discharge pipeline 5 is parallel to the surface of the fluidizing plate 6, and the spacing H is 100 nm. This inclination angle design facilitates the smooth flow of fluidized powder, reduces the wear of powder on the pipe wall, reduces powder density fluctuation, and lowers the vibration frequency of the discharge pipeline 5. In some embodiments, the upward inclination angle θ3 of the discharge port 501 of the discharge pipeline 5 is between 60-80°, the bottom of the discharge pipeline 5 is parallel to the surface of the fluidizing plate 6, and the spacing H is between 80-130 mm.

[0054] Example 2 A uniformly distributed feed and discharge powder silo conveying structure is adopted to complete the medium-high pressure dense phase conveying of dry powder. The vertical pressure silo body 1 is designed with a pressure of 4.0MPa. The cone angle of the secondary powder distribution cone component 2 is 40°, and the distance between the outer circle and the inner wall of the silo body is 80mm. Seven multi-point fluidizer pipe ports 3 are set on the lower side of the silo body 1, with an angle of 50° with the outer shell of the silo body 1, and are divided into two layers according to height. Four stainless steel powder collectors 4 are set at the bottom of the silo 1, and four discharge pipelines 5 are matched. The outlet of the discharge pipe 501 is inclined upward at an angle of 70°, and the distance between the bottom of the pipe port and the surface of the fluidizing plate 6 is 100mm. The upper part of the fluidizing plate 6 is evenly divided into four zones, and the number and opening angle of the fluidizing holes in each zone are consistent.

[0055] The specific conveying steps are as follows: Step 1: Introducing fluidizing gas: Nitrogen gas is selected as the fluidizing gas and introduced into the chamber 1 in two streams. The pressure of the bottom fluidizing gas is controlled at 0.6 MPa. It forms a swirling fluidizing gas flow through the four zones of the fluidizing plate 6 and is evenly introduced into the corresponding powder collector 4. The pressure of the lower layer fluidizing gas at the side multi-point fluidizer port 3 is 0.4 MPa, and the pressure of the upper layer fluidizing gas is 0.3 MPa. It enters the chamber in a circumferential and tangential flow form and couples with the bottom fluidizing gas. Step 2, Powder Feeding: Four feed inlets (101) are used for feeding in a diagonal alternating manner. Each set of inlets has a single feeding time of 35 minutes, with a 5-minute interval before switching to another set of inlets. The dry powder bulk density is 0.8 t / m³. 3 The feed rate is controlled at 80 t / (h) (pipe opening), every 35 minutes of feeding, pause feeding for 5 minutes, and cooperate with the side fluidizing gas to purge the secondary powder distribution cone component 2 surface; Step 3, Powder fluidization: First, turn on the side multi-point fluidizer port 3 to supply air and maintain it for 6 minutes to initially fluidize the dry powder on the surface of the bin; then turn on the bottom fluidization plate 6 to supply air; at the same time, the four auxiliary purging ports at the connection between the secondary powder distribution cone component 2 and the bin body 1 are opened simultaneously, with a purging air pressure of 0.7 MPa, each purging lasts for 12 seconds, with an interval of 35 minutes, to remove dead corner deposited powder and ensure that there are no fluidization dead zones in the bin; Step 4, uniform discharge: Divide the 4 discharge pipelines 5 into 2 groups of 2 pipelines each. Based on the pressure difference of the powder silo and the fluidized state of the dry powder, continuous discharge is achieved. The fluidized dry powder enters the corresponding powder collector 4 under the push of gravity and fluidizing gas, and flows out smoothly through the inclined upward discharge pipeline 5. The dry powder flow rate of each discharge pipeline 5 is stable at 20t / h, and the flow rate fluctuation is ≤±2%.

[0056] In this embodiment, the dry powder is pulverized coal, and the uniformly distributed feed silo conveying structure of this embodiment is applied to the pressurized fluidized coal conveying system.

[0057] Example 3 A uniformly distributed feed and discharge silo conveying structure is adopted to complete the medium- and high-pressure dense phase conveying of biomass powder. The vertical pressure silo body 1 is designed with a pressure of 3.5MPa. The secondary powder distribution conical component 2 has a cone angle of 45° and a distance of 90mm between the outer circle and the inner wall of the silo body. Six multi-point fluidizer pipes 3 are set on the side of the lower part of the silo body, with an angle of 55° with the outer shell of the silo body, and are divided into 3 layers according to height. Three stainless steel powder collectors 4 are set at the bottom of the silo, and three discharge pipelines 5 are matched with them. The discharge pipes are inclined upward at an angle of 75° and the distance between the bottom of the pipe and the surface of the fluidizing plate is 110mm. The upper part of the fluidizing plate is evenly divided into 3 zones, and the number and opening angle of the fluidizing holes in each zone are consistent.

[0058] The specific conveying steps are as follows: Step 1: Introducing fluidizing gas: Carbon dioxide is selected as the fluidizing gas. After drying, it is preheated to 65℃ with a temperature fluctuation of ≤±2℃. It is divided into two streams and introduced into the chamber 1. The pressure of the bottom fluidizing gas is controlled at 0.7MPa. It forms a swirling fluidizing gas flow through the three zones of the fluidizing plate 6 and is evenly introduced into the corresponding powder collector 4. The pressure of the lower layer fluidizing gas at the side multi-point fluidizer port 3 is 0.5MPa, the middle layer is 0.4MPa, and the upper layer is 0.3MPa. It enters the chamber in a circumferential and tangential flow form, and forms a coupling effect with the bottom fluidizing gas. Step 2, Powder Feeding: The biomass powder is pre-treated by grinding, with a particle size ≤200μm; it is continuously fed through 3 feed ports 101, and the feeding rate is controlled at 60t / (h). (pipe opening), every 40 minutes of feeding, pause feeding for 5 minutes, and use side fluidizing gas to purge the surface of the secondary powder distribution cone component 1 to prevent biomass powder from adhering and clumping. Step 3, Powder fluidization: First, open the side multi-point fluidizer port 3 to supply air and maintain it for 7 minutes to initially fluidize the surface biomass powder in the bin; then open the bottom fluidization plate 6 to supply air; at the same time, open the 6 auxiliary purging ports at the connection between the secondary powder distribution cone component 2 and the bin body 1, with a purging air pressure of 0.9 MPa, each purging lasts 15 seconds, with an interval of 30 minutes, to remove dead corner deposited powder and ensure that there are no fluidization dead zones in the bin; Step 4, uniform discharge: The three discharge pipelines 5 are grouped together. Based on the pressure difference of the powder silo and the fluidized state of the biomass powder, continuous discharge is achieved. The fluidized biomass powder enters the corresponding powder collector 4 under the push of gravity and fluidizing gas, and flows out smoothly through the inclined upward discharge pipeline 5. The biomass powder flow rate of each discharge pipeline 5 is stable at 18t / h, and the flow rate fluctuation is ≤±3%.

[0059] The uniformly distributed feed and discharge powder silo conveying structure in this embodiment is applied to a pressurized fluidized conveying system for biomass powder.

[0060] Therefore, the conveying method of the present invention, through the process design of step-by-step fluidization, directional guidance and precise discharge, can flexibly adjust the fluidizing gas pressure, flow rate and feed rate according to the characteristics of the powder (such as viscosity and particle size) and the conveying requirements, and is suitable for conveying various powder materials such as dry powder and biomass powder. At the same time, the process steps are simple, the coordination of each link is strong, no complex manual intervention is required, and automated continuous operation can be achieved, reducing the difficulty of operation and labor costs. It is also easy to seamlessly connect with subsequent gasification, reaction and other process units, and improve the stability and efficiency of the overall production process.

[0061] Comparative Example 1 Comparative Example 1 shows a traditional bottom-discharge powder silo structure, such as... Figure 4 As shown, it mainly includes a vertical silo body 8, a discharge pipe 9 at the bottom of the silo body, and a fluidizing airflow device 10. The top of the vertical silo body 8 has a single feed hole 801, through which powder falls vertically into the vertical silo body 8. A vertical discharge pipe 9 is located at the center of the bottom of the vertical silo body 8, and a fluidizing airflow device 10 (including a single fluidizing disc) is installed at the inlet of the discharge pipe 9 to introduce fluidizing gas into the vertical silo body 8, causing the powder to become fluidized, and then output through the vertical discharge pipe 9. The fluidizing disc is an integral structure without partitioning.

[0062] Its working principle is as follows: the powder falls vertically from the single feed hole 801 at the top of the vertical silo 8 and accumulates at the bottom of the vertical silo 8 under the action of gravity; the fluidized airflow device 10 introduces fluidizing gas into the vertical silo 8, so that the powder accumulated at the bottom forms a fluidized state. Under the combined action of gravity and the thrust of the fluidizing gas, the fluidized powder is conveyed downward along the vertical discharge pipe 9 to complete the powder transfer.

[0063] Therefore, compared to the uniformly distributed feed and discharge powder silo conveying structure of the present invention, this bottom discharge method has the following drawbacks: The equipment is tall and requires a large investment: Because a vertical discharge pipeline and a matching flow air device 10 need to be installed at the bottom of the vertical silo 8, the overall height of the powder silo device is significantly increased, which not only occupies more space, but also increases the investment cost of equipment manufacturing and installation.

[0064] Poor feed uniformity: The powder falls vertically directly from the top, which can easily cause local accumulation in the vertical silo 8. For sticky powders such as biomass powder, there will also be particle adhesion and agglomeration, resulting in uneven distribution of powder in the vertical silo 8.

[0065] Poor fluidization and discharge stability: The fluidizing gas distribution of the integral fluidizing disc is uneven, and fluidization dead zones are easily formed in the vertical silo 8, resulting in some powder materials failing to fluidize fully and clumping; the design of the bottom discharge pipe 9 is easily affected by the material accumulation state in the silo, resulting in large fluctuations in discharge flow rate, and the powder material has a large impact on the pipe wall when flowing in the vertical discharge pipe 9, which can easily cause pipeline vibration.

[0066] Comparative Example 2 Comparative Example 2 uses a traditional side-discharge powder silo structure, such as... Figure 5 As shown, the structure includes a vertical silo body 8, multiple discharge pipes 9 on the lower side of the silo body, and a shared fluidizing disc 11 at the bottom of the silo body. The top of the vertical silo body 8 is provided with a feed hole 801, allowing powder to fall directly and vertically into the silo. Three to four discharge pipes 9 are arranged circumferentially on the lower side of the vertical silo body 8. All discharge pipes 9 correspond to the same shared fluidizing disc 11 at the bottom of the silo body. The shared fluidizing disc 11 is an integral, unpartitioned structure used to introduce fluidizing gas into the silo. The vertical silo body 8 and the feed hole 801 are made of ordinary carbon steel, while the discharge pipes 9 are made of low-alloy steel.

[0067] Its working principle is as follows: the powder falls vertically into the silo from the top feed hole 801 of the vertical silo body 8 and accumulates. The shared fluidizing plate 11 introduces fluidizing gas into the silo, so that the powder in the silo forms a fluidized state. Under the action of the fluidizing gas and gravity, the fluidized powder flows to the multiple discharge pipes 9 on the side of the silo body and is output through the discharge pipeline 9.

[0068] Therefore, compared to the uniformly distributed feed and discharge powder silo conveying structure of the present invention, this side discharge method has the following drawbacks: The phenomenon of "powder grabbing" at the discharge point is serious: multiple discharge pipes 9 share an integral shared fluidizing plate 11. The fluidizing gas output from the shared fluidizing plate 11 is unevenly distributed in the bin, resulting in differences in powder concentration and pressure near each discharge pipe 9. This easily leads to "powder grabbing" in some discharge pipes and insufficient feed in some pipes.

[0069] Large flow fluctuations and frequent pipeline vibrations: Due to the "powder grabbing" phenomenon and uneven distribution of fluidizing gas, the mass flow rate of powder in each discharge pipeline 9 fluctuates greatly, making it impossible to guarantee uniform phase conveying; at the same time, the flow state of powder in the discharge pipeline 9 is unstable, which can easily cause high-frequency vibration of the pipeline and affect the service life of the discharge pipeline 9.

[0070] There is a fluidization dead zone in the silo: The fluidization range of the integrated shared fluidizing tray 11 is limited, and the structure of side discharge restricts the flow. The area between the inner wall of the vertical silo body 8 and the discharge pipe 9 is prone to forming a fluidization dead zone. Powder is prone to sticking to the wall, depositing and agglomerating, which further affects the conveying stability.

[0071] Poor feeding uniformity: The direct vertical drop method from the top causes uneven accumulation of powder in the silo, and sticky powder is prone to sticking and clumping, which aggravates the problem of uneven discharge.

[0072] Through the above comparison, it can be seen that the uniformly distributed feed and discharge powder silo conveying structure provided by the present invention has the advantages of existing technologies, which have problems such as powder accumulation, agglomeration and accumulation in the bottom discharge, resulting in powder agglomeration and unstable flow, and the side discharge, where the powder is often caught between several discharge pipes, and the powder pipeline has large fluctuations in mass flow rate and vibration. The present invention optimizes the feed and discharge structure and fluidization method to achieve uniform feeding, fluidization without dead zones and stable discharge of powder, thus meeting the stringent requirements of powder conveying under medium and high pressure conditions.

[0073] It should be understood that the present invention is not limited to what has been described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A uniformly distributed feed and discharge powder silo conveying structure, characterized in that, Includes the silo body, secondary powder distribution conical component, multi-point fluidizer inlet, powder collector, discharge pipeline and fluidizing disc; The top of the silo is provided with a feed inlet, and a secondary powder distribution cone component is set on the top side of the silo body, with the feed inlet arranged inside the secondary powder distribution cone component. The multi-point fluidizer inlet is located on the lower side of the silo body; The powder collector is located at the bottom of the silo, and the discharge pipeline corresponds one-to-one with the powder collector and is arranged at an angle upward. The fluidizing disc is located at the bottom of the powder collector, and its upper part is evenly divided into sections according to the number of powder collectors, with each section corresponding to a single powder collector.

2. The structure according to claim 1, characterized in that, The secondary powder distribution cone component is coaxially arranged with the silo body.

3. The structure according to claim 1, characterized in that, The multi-point fluidizer inlet is supplied with fluidizing gas in a circumferential and tangential flow pattern.

4. The structure according to claim 1, characterized in that, The number of fluidizing holes and the opening angle are consistent in each zone of the fluidizing disk.

5. The structure according to claim 1, characterized in that, The secondary powder distribution cone-shaped component is fixed to the outer shell of the silo by ribs.

6. The structure according to claim 1, characterized in that, The structure, volume, and dimensional parameters of the powder collectors are all consistent.

7. A method for conveying powder, characterized in that, The structure described in any one of claims 1-6 includes the following steps: Step 1, Introduce fluidizing gas: Divide the fluidizing gas into two streams. One stream is introduced from the bottom of the silo, and after passing through each section of the fluidizing plate, it forms a swirling fluidizing gas flow, which is then evenly introduced into the corresponding powder collector. The other stream enters the silo from the multi-point fluidizer pipe on the side of the silo in a circumferential and tangential flow form, and couples with the fluidizing gas at the bottom. Step 2, Powder feeding: The powder is fed in through the feed pipe at the top of the silo. Under the guidance of the secondary powder distribution cone component, the powder is evenly dropped into the middle of the silo to avoid local accumulation and adhesion. Step 3, Powder fluidization: Under the synergistic effect of two streams of fluidizing gas, the powder forms a gas-solid two-phase fluidized material in the silo, and there are no fluidization dead zones in the silo, which effectively prevents the powder from agglomerating. Step 4, Uniform Discharge: Under the impetus of gravity and fluidizing gas, the fluidized material enters the powder collector at the bottom of the silo. With the assistance of the swirling fluidizing gas flow, it flows smoothly out of the silo through the upward-sloping discharge pipeline corresponding to each collector, thus achieving uniform distribution and stable conveying of the powder.

8. The powder conveying method according to claim 7, characterized in that, In step 1, the two fluidizing gases have different pressures. The fluidizing gas introduced from the bottom of the chamber has a pressure 0.2-0.5 MPa higher than the fluidizing gas introduced from the multi-point fluidizer inlet.

9. A pressurized fluidized bed conveying system for pulverized coal, characterized in that, The system includes the uniformly distributed feed and discharge powder silo conveying structure as described in any one of claims 1-6.

10. A pressurized fluidized bed conveying system for biomass powder, characterized in that, The system includes the uniformly distributed feed and discharge powder silo conveying structure as described in any one of claims 1-6.

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