Cold hydrogenation fluidized bed, system and control method thereof

Abstract

The invention relates to the field of polycrystalline silicon, in particular to a cold hydrogenation fluidized bed, a system and a control method of the cold hydrogenation fluidized bed. The four inner cyclone separators are all arranged in the inner cavity and are respectively provided with an air outlet at the upper sealing head of the fluidized bed body; the gas collecting end of each of the two gas collecting pipes is correspondingly communicated with the gas outlets of the two inner cyclone separators respectively; the herringbone pipe is provided with a converging section positioned at the top and two branch sections which are respectively communicated with the bottom of the converging section; the bottoms of the two branch sections are respectively and correspondingly communicated with the gas phase outlets of the two gas collecting pipes; the two silicon powder detectors are respectively embedded in the two branch sections and are used for monitoring the particle size and the concentration of the silicon powder in the corresponding branch sections. Two gas phase outlets are arranged, so that the problem of a single gas phase outlet of the fluidized bed is avoided, the working efficiency of the four cyclone separators is effectively improved, and the silicon consumption is reduced; meanwhile, by arranging the silicon powder detector, the inner cyclone efficiency is conveniently regulated and controlled, and the high conversion rate of the fluidized bed is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of polysilicon, and in particular to a cold hydrogenated fluidized bed, a fluidized bed control system including the cold hydrogenated fluidized bed, and a control method corresponding to the fluidized bed control system. Background Art

[0002] The cold hydrogenation fluidized bed is a key equipment used in polysilicon production, mainly used to convert the by-product silicon tetrachloride into useful trichlorosilane, thereby improving raw material utilization and reducing waste.

[0003] At present, there are four inner cyclone separators inside the cold hydrogenation fluidized bed, and the four inner cyclones are connected in parallel at the gas phase outlet of the fluidized bed. Once the discharge pipe corresponding to one of the inner cyclone separators is blocked or the corresponding wing valve fails, the working efficiency of the inner cyclone separator will decrease or the airflow will be short-circuited, which will cause a large amount of active silicon powder to be discharged through the outer cyclone separator, and the silicon powder particle size will be large, resulting in high unit silicon consumption.

[0004] Meanwhile, to address issues like internal cyclone separator failure, feed pipe blockage, and flap valve failure in the hydrocooling fluidized bed, the traditional method is to determine the amount of silicon powder discharged. However, when large amounts of silicon powder are discharged, the hydrocooling system must be shut down before repairs can be made to the internal cyclone separator, feed pipe, and flap valve. This significantly increases maintenance costs and severely impacts the efficiency of the hydrocooling fluidized bed. Summary of the Invention

[0005] Based on the above problems, the present application provides a cold hydrogenated fluidized bed, a fluidized bed control system including the cold hydrogenated fluidized bed, and a corresponding control method of the fluidized bed control system.

[0006] To achieve this goal, in the first aspect, the technical solution adopted in this application is: A cold hydrogenation fluidized bed is provided, comprising: a fluidized bed body having an inner cavity; Four inner cyclone separators, each of which is disposed in the inner cavity and is provided with an air outlet communicating with the outside at an upper end of the fluidized bed body; Two gas collecting pipes, wherein the two gas collecting ends of each gas collecting pipe are respectively connected to the gas outlets of the two inner cyclone separators; A humanoid tube having a converging section at the top and two branching sections respectively connected to the bottom of the converging section, wherein the bottoms of the two branching sections are respectively connected to the gas phase outlets of the two gas collecting pipes; Two silicon powder detectors are respectively embedded in the two branch segments and are used to monitor the particle size and concentration of the silicon powder in the corresponding branch segments.

[0007] In addition to one or more of the features described herein, or as an alternative, further embodiments of the cold hydrogenation fluidized bed may include: a manhole is provided at the upper head of the fluidized bed body, and the manhole is located on the central axis of the fluidized bed body; the four inner cyclone separators are arranged at equal intervals in the circumferential direction around the central axis of the fluidized bed body, and the gas phase outlets of the two gas collecting pipes are respectively located on opposite sides of the manhole.

[0008] In addition to or instead of one or more features described herein, further embodiments of the cold hydrogenation fluidized bed may include: a jacket is provided on the outside of the manifold for sealing gaps on the manifold; the gaps include cracked welds and gaps caused by failure of the silicon powder detector.

[0009] In addition to or as an alternative to one or more features described herein, further embodiments of the cold hydrogenation fluidized bed may include: a pressure monitoring device and a nitrogen charging system are provided on the jacket, and the nitrogen charging system is used to charge nitrogen into the jacket when the pressure monitoring device detects an abnormal increase in pressure in the jacket, until the nitrogen pressure is greater than the pressure in the man-shaped tube and the difference is a first preset value.

[0010] In addition to one or more features described herein, or as an alternative, further embodiments of the cold hydrogenation fluidized bed may include: four discharge assemblies corresponding to the four inner cyclone separators are also provided in the inner cavity, each discharge assembly includes a collecting hopper, a discharge pipe, a wing valve, a cyclone breaking pipeline and a purge pipeline, the collecting hopper, the discharge pipe and the wing valve are connected to the bottom of the inner cyclone separator in sequence, one end of the cyclone breaking pipeline is provided at the collecting hopper and communicates with the interior of the collecting hopper, and the other end is fixedly mounted on the side wall of the inner cavity and connected to the cyclone breaking control device outside the inner cavity; one end of the purge pipeline is provided at the discharge pipe and communicates with the interior of the discharge pipe, and the other end is fixedly mounted on the side wall of the inner cavity and connected to the purge control device outside the inner cavity.

[0011] In addition to or as an alternative to one or more features described herein, further embodiments of the cold hydrogenation fluidized bed may include: the number of purge lines in each discharge assembly is two, and the two purge lines are respectively arranged in the middle and bottom of the discharge pipe.

[0012] The second aspect of the present application provides a fluidized bed control system, including an operating station, the above-mentioned cold hydrogenated fluidized bed, a first barometer for monitoring the internal air pressure of the cold hydrogenated fluidized bed, a vortex breaking control device and a purge control device; the cold hydrogenated fluidized bed is also provided with four discharge assemblies corresponding to the four inner cyclone separators, each discharge assembly includes a collecting hopper, a discharge pipe, a wing valve, a vortex breaking pipeline and two purge pipelines, the collecting hopper, the discharge pipe and the wing valve are connected to the bottom of the inner cyclone separator in sequence, the vortex breaking control device is connected to the inner cyclone separator through the vortex breaking pipeline The interior of the collecting hopper is connected, and the purge control device is connected to the middle cavity and the bottom cavity of the discharge pipe through the two purge pipelines respectively; the operation station is respectively connected to each silicon powder detector of the cold hydrogenation fluidized bed, the first barometer, the vortex breaking control device and the purge control device signal; the outside of the man-shaped tube of the cold hydrogenation fluidized bed is provided with a jacket for sealing the gap on the man-shaped tube, and the jacket is provided with a pressure monitoring device and a nitrogen charging system; the operation station is also respectively connected to the pressure monitoring device and the nitrogen charging system signal.

[0013] A third aspect of the present application provides a fluidized bed control method, which is applied to an operating station in the above-mentioned fluidized bed control system, comprising: Upon detecting a coarse particle abnormal escape signal sent by any of the silicon powder detectors, obtaining current discharge data of the corresponding two inner cyclone separators collected by the purge control device, and the fluidized bed air pressure collected by the first barometer; the current discharge data includes the airflow rate in the middle cavity and the bottom cavity of the discharge pipe corresponding to each inner cyclone separator, and the air pressure in the bottom cavity of the discharge pipe; If the air flow in the middle cavity and the bottom cavity of the discharge pipe is normal, and the difference between the air pressure in the bottom cavity and the air pressure of the fluidized bed is lower than a second preset value, an alarm prompt indicating that the corresponding wing valve is in a normally open state is displayed; Controlling the purge control device to adjust the purge flow rate of the middle cavity of the discharge pipe to a minimum non-zero value, and gradually reducing the purge flow rate of the bottom cavity of the discharge pipe until the wing valve is detected to be in a closed state; The difference between the air pressure in the bottom cavity of the discharge pipe and the air pressure of the fluidized bed is continuously monitored. In response to detecting that the difference exceeds a first threshold, the purge control device is controlled to slowly adjust the purge flow rate of the middle cavity and the bottom cavity of the discharge pipe to a normal value.

[0014] In one embodiment, the method further comprises: If the air flow rate values ​​in the middle cavity and the bottom cavity of the feed pipe are lower than the third preset value, and the difference between the air pressure in the middle cavity and the air pressure in the bottom cavity exceeds the second threshold, an alarm prompt indicating that the feed pipe is blocked is displayed; Controlling the purge control device to quickly increase the purge flow rate of the middle cavity of the discharge pipe and perform intermittent purge until it is detected that the air flow rate value in the middle cavity of the discharge pipe exceeds a third threshold value, and controlling the purge control device to reduce the purge flow rate of the middle cavity of the discharge pipe to a fourth preset value and continue the purge for the first preset time; When it is detected that the long blowing of the middle cavity of the discharge pipe is completed, the purge control device is controlled to increase the purge flow of the bottom cavity of the discharge pipe and perform intermittent explosive blowing until it is detected that the air flow in the middle cavity and the bottom cavity of the discharge pipe is normal.

[0015] In one embodiment, the method further comprises: If it is detected that the particle size of the silicon powder collected by any of the silicon powder detectors is continuously smaller than a fourth threshold value for a second preset time period, a prompt message that the efficiency of the corresponding inner cyclone separator is too high is displayed; Controlling the cyclone breaking control device to adjust the airflow into the corresponding collecting hopper to destroy the internal cyclone field and cause the silicon powder with larger particle size to be discharged with the gas phase, while shielding the alarm function of the silicon powder detector; When it is detected that the silicon powder particle size collected by the silicon powder detector is still smaller than the fourth threshold value, the rotation-breaking control device is controlled to increase the flow rate of the incoming airflow until the silicon powder particle size collected by the silicon powder detector is within the target value range.

[0016] In one embodiment, the fluidized bed control system further comprises a second barometer for monitoring the air pressure in the humanoid tube; the method further comprises: acquiring in real time first pressure data in the jacket collected by the pressure monitoring device; In response to detecting an abnormal rise in the first pressure data, an alarm prompt of abnormal jacket pressure is displayed, and the nitrogen filling system is controlled to fill nitrogen into the jacket until the first pressure data is greater than the second pressure data collected by the second barometer and the difference is a first preset value.

[0017] One of the above technical solutions has the following advantages or beneficial effects: by adopting four cyclone separators connected to two gas collecting pipes respectively, the fluidized bed has two gas phase outlets, avoiding the problems existing in a single gas phase outlet, effectively improving the working efficiency of the four cyclone separators, and reducing silicon consumption; at the same time, by arranging a silicon powder detector on the man-shaped tube, it is convenient to realize online monitoring of the particle size and concentration of silicon powder in the fluidized bed, and then it is convenient for the operation station to adjust the internal cyclone efficiency online in real time according to the monitoring results, so as to achieve a high conversion rate of the fluidized bed. At the same time, it can effectively avoid the enrichment of silicon powder in the four-stage heat exchanger tube bundle behind the fluidized bed, resulting in blockage of the heat exchanger tube bundle and decreased heat exchange efficiency.

[0018] Other advantages of the present application and the technical effects of the preferred embodiments will be further described in the following specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0020] Figure 1 Schematic diagram of the structure of the fluidized bed control system provided in the embodiment of the present application; Figure 2 1 is a side view schematic diagram of a cold hydrogenation fluidized bed provided in an embodiment of the present application; Figure 3 1 is a schematic top view of a cold hydrogenation fluidized bed provided in an embodiment of the present application; Figure 4 This is a schematic structural diagram of a humanoid tube and a jacket provided in an embodiment of the present application; Figure 5 It is a flow chart of the fluidized bed control method provided in the embodiment of the present application.

[0021] Among them, the reference numerals in the figures are: DETAILED DESCRIPTION

[0022] The following describes in detail embodiments of the present application, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly indicate the quantity of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0024] It should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0025] In this application, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art will understand the specific meanings of these terms in this application based on specific circumstances.

[0026] In addition, in the description of the present application, “a plurality of” means two or more, unless otherwise clearly and specifically defined.

[0027] In order to overcome the problems of uneven thermal stress distribution in the fluidized bed, which leads to cracking of the upper head weld, low efficiency of the cyclone separator in the fluidized bed, inability to realize online monitoring and regulation of the fluidized bed, easy clogging of the feed pipe, low fluidized bed conversion rate, high silicon consumption, etc., this application provides a cold hydrogenated fluidized bed, a fluidized bed control system and a fluidized bed control method, and further provides a new cold hydrogenated dual-outlet fluidized bed with online control of silicon powder, a fluidized bed system and a corresponding control method. Figures 1 to 5 Take the above content provided in this application as an example to illustrate and introduce.

[0028] like Figures 1 to 4 As shown, the present application provides a cold hydrogenation fluidized bed, comprising a fluidized bed body 1, four inner cyclone separators 2, two gas collecting pipes 3, a man-shaped tube 4 and two silicon powder detectors 5; wherein, the fluidized bed body 1 has an inner cavity 100, the four inner cyclone separators 2 are all arranged in the inner cavity 100 and are respectively provided with an air outlet 20 connected to the outside at the upper head 11 of the fluidized bed body 1; the two air collecting ends 31 of each air collecting pipe 3 are respectively connected to the air outlet 20 of the two inner cyclone separators 2; the man-shaped tube 4 has a converging section 41 at the top and two branch sections 42 respectively connected to the bottom of the converging section 41, and the bottoms of the two branch sections 42 are respectively connected to the gas phase outlets 30 of the two gas collecting pipes 3; the two silicon powder detectors 5 are respectively embedded in the two branch sections 42 and are used to monitor the particle size and concentration of the silicon powder in the corresponding branch sections 42.

[0029] As can be seen from the above, the cold hydrogenation fluidized bed has two gas phase outlets 30, so it is necessary to use a specially designed herringbone shaped pipe fitting, that is, the above-mentioned herringbone pipe 4. In a specific embodiment, as Figure 4 As shown, the outlet diameter D of the human-shaped tube 4 is 400-500 mm, the bending radius R=4D, and the length can be 2500-3000 mm. Of course, the specific length can also be set according to the pipeline layout requirements.

[0030] Optionally, an opening may be provided on the humanoid tube 4. The position of the opening needs to be determined by stress calculation and is mainly located in the vertical section of the humanoid tube 4, such as Figure 4 The two vertical sections at the bottom end of the branch section 42 of the man-shaped tube 4 are provided with openings for installing two silicon powder detectors 5. The silicon powder detectors 5 can be designed as an internal insertion type and connected to the man-shaped tube 4 via a flange.

[0031] For the double-outlet fluidized bed proposed in this application, by designing Figure 4 The manifold 4 shown in the figure, with a silicon dust detector 5 installed on the side of its vertical section, enables online monitoring of the silicon dust particle size and concentration at the fluidized bed outlet. This allows the downstream computer system to analyze the test data in real time and promptly feedback the results to the operation station. This silicon dust detector 5 is resistant to high temperatures, high pressures, explosions, and corrosion, and offers high-precision silicon dust particle size detection capabilities. It can also rapidly process data on the engineering machine, enabling real-time online feedback on silicon dust particle size and concentration.

[0032] To ensure system stability, this application utilizes a design where two internal cyclone separators 2 correspond to one gas collecting pipe 3 and gas phase outlet 30. This design effectively prevents problems such as internal flow deviation and short circuits within the fluidized bed caused by failure of the internal cyclone separators 2. This dual-outlet fluidized bed's dual safeguard mechanism ensures both the accuracy of test data and the operational reliability and safety of the entire fluidized bed system.

[0033] By adopting four cyclone separators connected to two gas collecting pipes 3 respectively, the fluidized bed has two gas phase outlets 30, avoiding the problems existing in the single gas phase outlet 30, effectively improving the working efficiency of the four cyclone separators, and reducing silicon consumption; at the same time, by arranging a silicon powder detector 5 on the man-shaped tube 4, it is convenient to realize online monitoring of the particle size and concentration of silicon powder in the fluidized bed, and then it is convenient for the operation station to adjust the internal cyclone efficiency online in real time according to the monitoring results, so as to achieve a high conversion rate of the fluidized bed, and at the same time, it can effectively avoid the enrichment of silicon powder in the four-stage heat exchanger tube bundle behind the fluidized bed, which leads to problems such as blockage of the heat exchanger tube bundle and reduced heat exchange efficiency.

[0034] In at least one embodiment, Figure 3 As shown, a manhole 200 is also provided at the upper head 11 of the fluidized bed body 1, and the manhole 200 is located on the central axis of the fluidized bed body 1; four inner cyclone separators 2 are arranged at equal intervals along the circumferential direction around the central axis of the fluidized bed body 1, and the gas phase outlets 30 of the two gas collecting pipes 3 are respectively located on opposite sides of the manhole 200.

[0035] A specific optional embodiment is that the fluidized bed head 11 has three outlets, the central area is a manhole 200, and a 400~500mm fluidized bed gas phase outlet 30 is provided on each side at a distance of 1000~1200mm from the center of the manhole 200, that is, the gas phase outlet 30 of the above-mentioned gas collecting pipe 3. The three outlets can all be realized by inserting components.

[0036] Among them, optionally, the gas phase outlet 30 insertion pipes on both sides can be connected to the gas collecting pipe 3 by welding, and the two gas collecting pipes 3 are ensured to be horizontally parallel, and the two sides of the gas collecting pipe 3 are welded to the gas outlet 20 of the inner cyclone separator 2, wherein the inner cyclone separator 2 can be installed vertically, and the center distance between the two gas collecting pipes 3 can be 2000~2100mm, and the center distance from the manhole 200 can be 1000~1200mm.

[0037] The upper head 11 of a traditional cold hydrogenation fluidized bed is usually manufactured in the form of plate splicing, with many dense welds. Welding defects and residual stress concentration, superimposed on the cold pressing deformation stress, the local stress exceeds the yield limit of the material, which easily leads to weld cracking. At the same time, the manhole 200 of the upper head 11 is off-center and uses a fillet weld. The wall thickness of the welding area increases sharply, and the excessive welding volume causes high residual stress, further exacerbating the risk of fillet weld cracking. The welding residual stress and the forming deformation stress are accumulated at the weld, forming a local stress peak that far exceeds the material's bearing capacity, resulting in serious uneven thermal stress distribution on the head 11 of the fluidized bed.

[0038] like Figure 3 As shown, in response to the problem of uneven thermal stress distribution during operation of the fluidized bed, which leads to cracks in the manhole 200 of the upper head 11, stress balance calculations are performed to move the manhole 200 to the center of the fluidized bed, with a gas phase outlet 30 opened on each side, thus uniquely proposing a dual-outlet fluidized bed. In response to the uneven thermal stress distribution of the fluidized bed, this application specifically modified the manhole 200; the manhole 200 of the fluidized bed is moved to the center, and a fluidized bed gas phase outlet 30 is opened on each side to solve the problem of uneven thermal stress distribution of the fluidized bed, avoid cracks in the upper and lower heads of the fluidized bed, and thus ensure the structural stability and safety of the fluidized bed body 1.

[0039] In at least one embodiment, a jacket 6 is provided on the outside of the man-shaped tube 4 for sealing gaps on the man-shaped tube 4 ; the gaps include cracked welds and gaps caused by failure of the silicon powder detector 5 .

[0040] Because the man-shaped tube 4 has high requirements for welding, problems such as failure of the weld or the inner cover of the silicon powder detector 5 may occur during operation, resulting in leakage of the fluidized bed, and more seriously, fire or explosion accidents. In order to avoid the above accident hazards, a sealing protection can be formed by adding a jacket 6 structure, which effectively enhances the leakage prevention ability of the man-shaped tube 4, and can effectively prevent cracked welds and leakage caused by sealing failure when the silicon powder detector 5 is installed on the man-shaped tube 4. The risk of weld leakage of the man-shaped tube 4 is significantly reduced, and the stability of equipment operation is improved; even if the sealing of the silicon powder detector 5 or other components installed on the man-shaped tube 4 fails, the jacket 6 can still ensure that the medium does not leak, thereby improving the safety and reliability of the system as a whole.

[0041] like Figure 4 As shown, since the fluidized bed is located in the middle of the fluidized bed at the manhole 200 , a specific embodiment is that the manhole 4 is in an arc shape near the manhole 200 and is bent away from the manhole 200 , so as to facilitate maintenance of the manhole 200 .

[0042] It should be noted that the jacket 6 is but not limited to being one-piece or split-welded. It can also be designed as a modular installation to facilitate assembly and disassembly of the jacket 6. The structure is not specifically limited as long as the jacket 6 is airtight.

[0043] In at least one embodiment, the jacket 6 is provided with a pressure monitoring device 61 and a nitrogen charging system 62. The nitrogen charging system 62 is used to charge nitrogen into the jacket 6 when the pressure monitoring device 61 detects an abnormal increase in the pressure in the jacket 6 until the nitrogen pressure is greater than the pressure in the human-shaped tube 4 and the difference is a first preset value.

[0044] Specifically, the pressure monitoring device 61 can be selected as a pressure gauge, which is used to collect the pressure in the jacket 6 online in real time. If an abnormal increase in pressure is found, it indicates that a leak has occurred. The regulating valve of the nitrogen filling system 62 is opened and protective nitrogen is filled into the jacket 6 to prevent safety accidents. The pressure gauge installed on the jacket 6 can transmit the pressure signal to the operating station online in real time. If the pressure rises rapidly, the pressure in the operating station will be alarmed online, triggering the chain to open the nitrogen filling system 62, so that the nitrogen pressure is higher than the first preset value of the air pressure in the man-shaped tube 4. The first preset value can be selected as 0.1MPa, and of course it can be set to other values ​​according to actual needs. This nitrogen filling method can effectively prevent the gas phase in the fluidized bed from flowing into the jacket 6, causing a safety accident, and by timely feedback to the operator, it can be made to perform emergency stop processing, thereby ensuring the safety of the jacket 6 structure and the entire fluidized bed structure.

[0045] In at least one embodiment, the inner cavity 100 is further provided with four discharge assemblies 7 corresponding to the four inner cyclone separators 2 respectively, and each discharge assembly 7 includes a collecting hopper 71, a discharge pipe 72, a wing valve 73, a cyclone breaking pipeline 74 and a purge pipeline 75. The collecting hopper 71, the discharge pipe 72 and the wing valve 73 are connected to the bottom of the inner cyclone separator 2 in sequence. One end of the cyclone breaking pipeline 74 is provided at the collecting hopper 71 and is connected to the interior of the collecting hopper 71, and the other end is fixedly mounted on the side wall of the inner cavity 100 and is connected to the cyclone breaking control device 8 outside the inner cavity 100; one end of the purge pipeline 75 is provided at the discharge pipe 72 and is connected to the interior of the discharge pipe 72, and the other end is fixedly mounted on the side wall of the inner cavity 100 and is connected to the purge control device 9 outside the inner cavity 100.

[0046] The cyclone breaking control device 8 and the purge control device 9 can both include a flow meter, a regulating valve, an orifice plate pipeline, and a check valve. The check valve is used to prevent material backflow, and the orifice plate pipeline can be kept open to prevent silicon powder from clogging the purge pipeline 75 and the cyclone breaking pipeline 74. The cyclone breaking pipeline 74 can be arranged at the opening of the collection hopper 71 of the inner cyclone system. The opening can be installed at an angle of 10 to 90 degrees upward to weld the air inlet pipe. When necessary, the cyclone breaking control device 8 can fill the collection hopper 71 with a large amount of hydrogen through the cyclone breaking pipeline 74 to disrupt the normal airflow of the cyclone, causing the inner cyclone separator 2 to discharge a large amount of silicon powder, thereby achieving online adjustment of the internal silicon powder particle size and silicon powder amount.

[0047] For details, please refer to Figure 1 The detection circuit within the vortex-breaking control device 8 may include a check valve, a regulating valve, a pressure gauge P1 (which can be understood as its measured value P1), and a flow meter FT1 (which can be understood as its measured value FT1). The check valve is installed near the vortex-breaking pipeline 74 and, together with the regulating valve, forms a series branch circuit. The pressure gauge P1 and the flow meter FT1 can be connected to this series branch circuit, respectively. The regulating valve, pressure gauge P1, and flow meter FT1 can all communicate with the operating station.

[0048] Similarly, the detection circuit within purge control device 9 may also include a check valve, a regulating valve, a pressure gauge, and a flow meter. The check valve is installed near purge line 75, and together with the regulating valve, it forms a series branch circuit, to which the pressure gauge and flow meter can be connected, respectively. The regulating valve, pressure gauge, and flow meter can also communicate with the operation station.

[0049] In at least one embodiment, the number of the purge lines 75 in each discharge assembly 7 is two, and the two purge lines 75 are respectively provided at the middle and the bottom of the discharge pipe 72 .

[0050] In this embodiment, if Figure 1As shown, the detection circuits in the purge control device 9 may be two independent ones. The detection circuit corresponding to the middle of the discharge pipe 72 may include a pressure gauge P2 and a flow meter FT2, and the detection circuit corresponding to the bottom of the discharge pipe 72 may include a pressure gauge P3 and a flow meter FT3. P2, P3, FT2, and FT3 may all be understood as the measurement values ​​of each instrument.

[0051] It should be noted that in this embodiment, since the function of the check valve is to prevent the backflow of materials in the fluidized bed, it only has a physical protection function. Therefore, in addition to the check valve, the above-mentioned regulating valves, pressure gauges, flow meters and other instrument devices can all have the functions of online data real-time transmission, operation and alarm. The data collected and operated by all instruments can be presented online at the operation station, and then the data can be processed and processed by the operation station to achieve the purpose of online regulation of the fluidized bed silicon powder particle size and concentration, and realize high-efficiency operation of the fluidized bed.

[0052] In another embodiment of the present application, since the problem of silicon powder blocking the discharge pipe 72 is common during the operation of the fluidized bed, the main reason is analyzed to be that the silicon skin generated during the start-up and shutdown process blocks the discharge pipe 72, resulting in blockage of the inner cyclone discharge pipe 72, and then causes the fluidized bed to deviate or short-circuit, causing a large amount of silicon powder to be discharged. Therefore, in this embodiment, by widening the diameter of the discharge pipe 72, silicon powder bridging can be effectively prevented, and the probability of large-particle silicon powder being entrained can be reduced.

[0053] By widening the diameter of the discharge pipe 72, the situation in which silicon powder bridges and blocks the discharge pipe 72 during the start-up and shutdown of the fluidized bed can be effectively avoided, the air velocity of silicon powder entrained in the inner cyclone can be reduced, and the probability of large-particle silicon powder entrainment can be reduced, thereby fundamentally avoiding the situation in which silicon powder bridges and blocks the material, and ensuring the normal and efficient operation of the inner cyclone separator 2.

[0054] The second aspect of the present application provides a fluidized bed control system, including an operating station, the above-mentioned cold hydrogenated fluidized bed, a first barometer 10 for monitoring the internal air pressure of the cold hydrogenated fluidized bed, a cyclone breaking control device 8 and a purge control device 9; the cold hydrogenated fluidized bed is also provided with four discharge assemblies 7 corresponding to the four inner cyclone separators 2, each discharge assembly 7 includes a collecting hopper 71, a discharge pipe 72, a wing valve 73, a cyclone breaking pipeline 74 and two purge pipelines 75, the collecting hopper 71, the discharge pipe 72 and the wing valve 73 are sequentially connected to the bottom of the inner cyclone separator 2, the cyclone breaking control device 8 is connected to the bottom of the inner cyclone separator 2, and the cyclone breaking control device 8 is connected to the bottom of the inner cyclone separator 2. The cyclone breaking pipeline 74 is connected to the interior of the collecting hopper 71, and the purge control device 9 is connected to the middle cavity and the bottom cavity of the discharge pipe 72 through two purge pipelines 75 respectively; the operation station is respectively connected to each silicon powder detector 5, the first barometer 10, the cyclone breaking control device 8 and the purge control device 9 of the cold hydrogenation fluidized bed by signal; the outside of the man-shaped tube 4 of the cold hydrogenation fluidized bed is provided with a jacket 6 for sealing the gap on the man-shaped tube 4, and the jacket 6 is provided with a pressure monitoring device 61 and a nitrogen charging system 62; the operation station is also respectively connected to the pressure monitoring device 61 and the nitrogen charging system 62 by signal.

[0055] The third aspect of the present application provides a fluidized bed control method, which is applied to the operating station in the above-mentioned fluidized bed control system, such as Figure 5 As shown, including: S502: Detecting the coarse particle abnormal escape signal sent by any silicon powder detector, obtaining the current discharge data of the corresponding two inner cyclone separators collected by the purge control device, and the fluidized bed pressure collected by the first barometer, for example Figure 1 P4 shown; the current discharge data includes the air flow in the middle cavity and the bottom cavity of the discharge pipe corresponding to each inner cyclone separator, and the air pressure in the bottom cavity of the discharge pipe.

[0056] When the silicon powder detector detects that the silicon powder particle size has been greater than a certain value for a preset period of time, it can generate a coarse particle abnormal escape signal and feed it back to the operation station, so that it can issue an alarm in time and perform online silicon powder particle size control according to the preset program.

[0057] At step S504, if the airflow in the middle and bottom chambers of the feed pipe is normal, and the difference between the air pressure in the bottom chamber and the pressure in the fluidized bed is lower than a second preset value, an alarm indicating that the corresponding flap valve is in the normally open state is displayed. The operator at the operating station can then identify the current fault type of the fluidized bed.

[0058] S506, controlling the purge control device to adjust the purge flow of the middle cavity of the discharge pipe to a minimum non-zero value, and gradually reducing the purge flow of the bottom cavity of the discharge pipe until the wing valve is detected to be in a closed state.

[0059] S508, continuously monitor the difference between the air pressure in the bottom cavity of the discharge pipe and the air pressure of the fluidized bed, and in response to detecting that the difference exceeds a first threshold, control the purge control device to slowly adjust the purge flow of the middle cavity and the bottom cavity of the discharge pipe to a normal value.

[0060] A specific implementation method is that the operation station detects Figure 1 The medium silicon powder detector OCM1 sends a coarse particle abnormal escape signal. At this time, OCM1 can be in alarm state. The operation station will quickly determine the working conditions of the two corresponding inner cyclone separators according to the preset program, and make a comprehensive judgment based on the pressures P2, P3, P4, and the hydrogen flow meters FT2 and FT3.

[0061] If the flow rates on flowmeters FT2 and FT3 are normal and the pressure differential between P3 and P4 is nearly zero, the flap valve is considered normally open. Adjust the purge flow rate in the middle of the feed pipe to a minimum flow rate, but not to zero, to prevent clogging of the purge line. Also, adjust the purge flow rate at the bottom of the feed pipe appropriately to allow the flap valve to close. Once the pressure differential between P3 and P4 exceeds 5 kPa, slowly adjust the flow rate to normal, and continue online monitoring of the silicon powder particle size and concentration using OCM1.

[0062] This implementation scheme addresses the issue of abnormal coarse particle escape during silicon fume production by achieving rapid response and precise handling through multi-parameter coordinated control. Specifically, this solution provides proactive preventive maintenance capabilities. Using a silicon fume detector to monitor particle size distribution and concentration changes in real time, it triggers an alarm at the early stages of coarse particle escape, preventing the problem from escalating and leading to unplanned shutdowns, effectively reducing production interruptions. Furthermore, a dynamic adjustment mechanism for the purge flow rate (maintaining a minimum flow rate but not zero) effectively prevents pipeline blockages while maintaining process stability, ensuring long-term reliable system operation.

[0063] In addition, this solution adopts a multi-parameter intelligent diagnosis system, using the pressure difference (P3-P4) as the core criterion for the status of the wing valve, and combining the data from the flow meters FT2 and FT3 for cross-validation, which greatly improves the accuracy of fault diagnosis. This solution also adopts a hierarchical control strategy, prioritizing the adjustment of the purge flow in the middle of the discharge pipe as the main control variable, and then auxiliary adjustment of the bottom purge flow when necessary, to form a step-by-step control mode. This step-by-step optimization method avoids over-adjustment or system oscillation, ensuring that the process parameters smoothly transition to the normal range. In addition, the solution also has closed-loop control optimization capabilities. After adjusting the purge flow, the silicon powder detector continuously detects and feedbacks the changes in silicon powder particle size and concentration online, realizing real-time verification and automatic adjustment of the control parameters of the operation station.

[0064] In one embodiment, the fluidized bed control method further comprises: If the air flow rate values ​​in the middle cavity and the bottom cavity of the discharge pipe are lower than the third preset value, and the difference between the air pressure in the middle cavity and the air pressure in the bottom cavity exceeds the second threshold, an alarm prompt indicating that the discharge pipe is blocked will be displayed; at this time, the operating station personnel can observe the current fault type of the fluidized bed.

[0065] Controlling the purge control device to quickly increase the purge flow rate of the middle cavity of the discharge pipe and perform intermittent purge until it is detected that the air flow value in the middle cavity of the discharge pipe exceeds a third threshold value, and controlling the purge control device to reduce the purge flow rate of the middle cavity of the discharge pipe to a fourth preset value and continue the purge for the first preset time; When it is detected that the long blowing of the middle cavity of the discharge pipe is completed, the purge control device is controlled to increase the purge flow of the bottom cavity of the discharge pipe and perform intermittent explosive blowing until it is detected that the air flow in the middle cavity and the bottom cavity of the discharge pipe is normal.

[0066] Of course, when it is detected that the air flow in the middle cavity and the bottom cavity of the discharge pipe is tending to be normal, the operation station can also control the purge control device to blow the middle cavity and the bottom cavity of the discharge pipe for a certain period of time through the orifice bypass flow to ensure that the pipeline residue is completely removed.

[0067] A specific implementation method is as follows: Figure 1 As shown, if the flow rates of flow meters FT2 and FT3 are almost zero, and the pressure difference of P2-P3 is greater than 15kPa (of course, this value can be adjusted according to actual conditions), it is judged that the discharge pipe is blocked, and the purge flow in the middle of the discharge pipe is instantly increased, and intermittent explosive blowing is performed to dredge the discharge pipe; if the flow rates of flow meters FT2 and FT3 gradually have values, they can be blown for a long time for 5 minutes, and then the purge flow at the bottom of the discharge pipe can be opened and intermittent explosive blowing can be performed. After the flow rates of flow meters FT2 and FT3 return to normal values, they can continue to be blown for a long time through the orifice bypass flow.

[0068] The operating station in this embodiment of the present application can diagnose blockages in the feed pipe and perform corresponding purge control. Through innovative multi-parameter collaborative monitoring and intelligent graded purge strategies, this significantly improves blockage handling efficiency while ensuring safe and stable system operation. This solution utilizes a dual-chamber flow and pressure differential composite judgment mechanism, which effectively reduces the false alarm rate compared to traditional single pressure monitoring methods and enables the operating station to identify minor blockages in the early stages.

[0069] In one embodiment, the fluidized bed control method further comprises: If it is detected that the silicon powder particle size collected by any silicon powder detector is continuously less than the fourth threshold value for the second preset time period, a prompt message indicating that the corresponding inner cyclone separator is too efficient is displayed; at this time, the operating station personnel can observe the current fault type of the fluidized bed.

[0070] At this time, the operating station will automatically determine that the efficiency of the separator has increased abnormally and start the de-swirl program, controlling the de-swirl control device to adjust the airflow into the corresponding collecting hopper to destroy its internal swirl field and cause larger-sized silicon powder to be discharged with the gas phase, while shielding the alarm function of the silicon powder detector. This step disturbs the internal flow field of the separator by precisely controlling the opening of the de-swirl pipeline regulating valve, so that the large-particle silicon powder that was originally over-captured can be discharged normally through the gas phase outlet. This active intervention measure can quickly restore the system particle size distribution to the 30-50μm range required by the process. The escape of large particles that may occur in the early stage of the de-swirl operation is effectively handled by the intelligent shielding function of the silicon powder detector, which not only ensures the accuracy of the monitoring data but also avoids the triggering of false alarms.

[0071] The operator detects that the silicon powder particle size collected by the silicon powder detector is still smaller than the fourth threshold value, and controls the rotation-breaking control device to increase the flow rate of the incoming air flow until the silicon powder particle size collected by the silicon powder detector is within the target value range.

[0072] A specific implementation method is as follows: Figure 1 As shown, if the silicon powder particle size is less than 30μm for 2 hours continuously, it is judged that the efficiency of the inner cyclone separator is too high. At this time, the operating station can open the regulating valve of the cyclone breaking pipeline to break the inner cyclone separator, disrupting the normal working airflow inside the inner cyclone separator, so that large particles of silicon powder can be discharged normally through the corresponding gas phase outlet. During the cyclone breaking, there is a phenomenon of large particles of silicon powder escaping. The operating station can control the silicon powder detector to shield it. If the silicon powder particle size is still small at this time, the cyclone breaking flow rate can be further increased to ensure that the final silicon powder particle size is within a controllable range.

[0073] This solution effectively solves the problem of small silicon powder particle size caused by the excessive efficiency of the inner cyclone separator through an intelligent cyclone breaking and control mechanism, achieving precise particle size control while ensuring the stability of the production process.

[0074] In one embodiment, the fluidized bed control system further comprises a second pressure gauge for monitoring the air pressure in the man-shaped tube; the fluidized bed control method further comprises: acquiring first pressure data in the jacket collected by a pressure monitoring device in real time; In response to detecting an abnormal rise in the first pressure data, an alarm prompt of abnormal jacket pressure is displayed, and the nitrogen filling system is controlled to fill nitrogen into the jacket until the first pressure data is greater than the second pressure data collected by the second pressure gauge and the difference is a first preset value.

[0075] The fluidized bed control system significantly improves the safety and stability of equipment operation by adding man-shaped tube air pressure monitoring and intelligent jacket pressure control mechanism.

[0076] It should be noted that the defects in the above solutions and the proposed solutions are the results obtained by the inventor after practice and careful research. Therefore, the discovery process of the above problems and the solutions proposed in the present disclosure for the above problems below should be the contributions made by the inventor to the present disclosure during the disclosure process.

[0077] In summary, the beneficial effects of the above solution provided by this application include at least: 1. The cold hydrogenation fluidized bed features a dual-outlet manhole located in the center of the upper head. The dual outlets are located on opposite sides of the manhole. This effectively avoids problems such as weld cracking caused by uneven thermal stress in the fluidized bed, eliminates safety hazards, and ensures the fundamental safety of the fluidized bed operation. Furthermore, the dual-outlet fluidized bed prevents the discharge of large amounts of silicon powder due to the failure of a single internal cyclone.

[0078] 2. The dust detector in the fluidized bed control system can promptly alarm and quickly identify the inner cyclone separator corresponding to the fault. The operation station can realize online abnormality processing and adjustment and optimization of the particle size of silicon powder discharged from the fluidized bed according to the preset program, ensuring that the efficiency of the inner cyclone can be adjusted online and achieving the stability of the fluidized bed conversion rate.

[0079] 3. In response to problems such as the failure of the seal of the man-shaped pipe welds and the online dust detector, additional jackets and protective measures are added to prevent fires caused by abnormal leakage and further improve the safety of the cold hydrogenation fluidized bed.

[0080] 4. In view of the problem that the existing fluidized bed discharge pipe is prone to silicon powder clogging during the start-up and shutdown process, the diameter of the discharge pipe can be appropriately increased to reduce the probability of silicon powder bridging and clogging. At the same time, the gas velocity of the discharged silicon powder can be moderately reduced to reduce the possibility of large particles of silicon powder being carried out of the fluidized bed.

[0081] Obviously, the above embodiments of the present application are merely examples for the purpose of clearly illustrating the present application, and are not intended to limit the embodiments of the present application. For those skilled in the art, other variations or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application shall be included within the scope of protection of the claims of the present application.

Claims

1. A cold hydrogenation fluidized bed, characterized in that: include: a fluidized bed body having an inner cavity; Four inner cyclone separators, each of which is disposed in the inner cavity and is provided with an air outlet communicating with the outside at an upper end of the fluidized bed body; Two gas collecting pipes, wherein the two gas collecting ends of each gas collecting pipe are respectively connected to the gas outlets of the two inner cyclone separators; A humanoid tube having a converging section at the top and two branching sections respectively connected to the bottom of the converging section, wherein the bottoms of the two branching sections are respectively connected to the gas phase outlets of the two gas collecting pipes; Two silicon powder detectors are respectively embedded in the two branch segments and are used to monitor the particle size and concentration of the silicon powder in the corresponding branch segments.

2. The cold hydrogenation fluidized bed according to claim 1, characterized in that A manhole is further provided at the upper end of the fluidized bed body, and the manhole is located on the central axis of the fluidized bed body; the four inner cyclone separators are arranged at equal intervals in the circumferential direction around the central axis of the fluidized bed body, and the gas phase outlets of the two gas collecting pipes are respectively located on opposite sides of the manhole; And / or, a jacket is provided on the outside of the man-shaped tube for sealing gaps on the man-shaped tube; the gaps include cracked welds and gaps caused by failure of the silicon powder detector.

3. The cold hydrogenation fluidized bed according to claim 2, characterized in that The jacket is provided with a pressure monitoring device and a nitrogen charging system. The nitrogen charging system is used to charge nitrogen into the jacket when the pressure monitoring device detects an abnormal increase in the pressure in the jacket, until the nitrogen pressure is greater than the pressure in the human-shaped tube and the difference is a first preset value.

4. The cold hydrogenation fluidized bed according to any one of claims 1 to 3, characterized in that The inner cavity is also provided with four discharge assemblies corresponding to the four inner cyclone separators respectively, and each discharge assembly includes a collecting hopper, a discharge pipe, a wing valve, a cyclone breaking pipeline and a purge pipeline. The collecting hopper, the discharge pipe and the wing valve are connected to the bottom of the inner cyclone separator in sequence, one end of the cyclone breaking pipeline is provided at the collecting hopper and communicates with the interior of the collecting hopper, and the other end is fixedly mounted on the side wall of the inner cavity and connected to the cyclone breaking control device outside the inner cavity; one end of the purge pipeline is provided at the discharge pipe and communicates with the interior of the discharge pipe, and the other end is fixedly mounted on the side wall of the inner cavity and connected to the purge control device outside the inner cavity.

5. The cold hydrogenation fluidized bed according to claim 4, characterized in that There are two purge lines in each discharge assembly, and the two purge lines are respectively arranged in the middle and bottom of the discharge pipe.

6. A fluidized bed control system, characterized in that: The device comprises an operating station, a cold hydrogenation fluidized bed according to any one of claims 1 to 5, a first barometer for monitoring the internal pressure of the cold hydrogenation fluidized bed, a cyclone breaking control device, and a purge control device; The cold hydrogenation fluidized bed is further provided with four discharge assemblies corresponding to the four inner cyclone separators, each of which includes a collecting hopper, a discharge pipe, a wing valve, a cyclone breaking pipeline and two purge pipelines. The collecting hopper, the discharge pipe and the wing valve are sequentially connected to the bottom of the inner cyclone separator. The cyclone breaking control device is connected to the interior of the collecting hopper through the cyclone breaking pipeline. The purge control device is connected to the middle cavity and the bottom cavity of the discharge pipe respectively through the two purge pipelines. The operation station is respectively connected to each silicon powder detector of the cold hydrogenation fluidized bed, the first barometer, the vortex breaking control device and the purge control device by signal; The outside of the man-shaped tube of the cold hydrogenation fluidized bed is provided with a jacket for sealing the gap on the man-shaped tube, and the jacket is provided with a pressure monitoring device and a nitrogen filling system; the operating station is also respectively connected to the pressure monitoring device and the nitrogen filling system for signal connection.

7. A fluidized bed control method, applied to the operating station of the fluidized bed control system according to claim 6, comprising: detecting a coarse particle abnormal escape signal sent by any of the silicon powder detectors, and obtaining current discharge data of the corresponding two inner cyclone separators collected by the purge control device, as well as the fluidized bed pressure collected by the first barometer; The current discharge data includes the air flow in the middle cavity and the bottom cavity of the discharge pipe corresponding to each inner cyclone separator, and the air pressure in the bottom cavity of the discharge pipe; If the air flow in the middle cavity and the bottom cavity of the discharge pipe is normal, and the difference between the air pressure in the bottom cavity and the air pressure of the fluidized bed is lower than a second preset value, an alarm prompt indicating that the corresponding wing valve is in a normally open state is displayed; Controlling the purge control device to adjust the purge flow rate of the middle cavity of the discharge pipe to a minimum non-zero value, and gradually reducing the purge flow rate of the bottom cavity of the discharge pipe until the wing valve is detected to be in a closed state; The difference between the air pressure in the bottom cavity of the discharge pipe and the air pressure of the fluidized bed is continuously monitored. In response to detecting that the difference exceeds a first threshold, the purge control device is controlled to slowly adjust the purge flow rate of the middle cavity and the bottom cavity of the discharge pipe to a normal value.

8. The fluidized bed control method according to claim 7, characterized in that: The method further comprises: If the air flow rate values ​​in the middle cavity and the bottom cavity of the feed pipe are lower than the third preset value, and the difference between the air pressure in the middle cavity and the air pressure in the bottom cavity exceeds the second threshold, an alarm prompt indicating that the feed pipe is blocked is displayed; Controlling the purge control device to quickly increase the purge flow rate of the middle cavity of the discharge pipe and perform intermittent purge until it is detected that the air flow rate value in the middle cavity of the discharge pipe exceeds a third threshold value, and controlling the purge control device to reduce the purge flow rate of the middle cavity of the discharge pipe to a fourth preset value and continue the purge for the first preset time; When it is detected that the long blowing of the middle cavity of the discharge pipe is completed, the purge control device is controlled to increase the purge flow of the bottom cavity of the discharge pipe and perform intermittent explosive blowing until it is detected that the air flow in the middle cavity and the bottom cavity of the discharge pipe is normal.

9. The fluidized bed control method according to claim 7, characterized in that: The method further comprises: If it is detected that the particle size of the silicon powder collected by any of the silicon powder detectors is continuously smaller than a fourth threshold value for a second preset time period, a prompt message that the efficiency of the corresponding inner cyclone separator is too high is displayed; Controlling the cyclone breaking control device to adjust the airflow into the corresponding collecting hopper to destroy the internal cyclone field and cause the silicon powder with larger particle size to be discharged with the gas phase, while shielding the alarm function of the silicon powder detector; When it is detected that the silicon powder particle size collected by the silicon powder detector is still smaller than the fourth threshold value, the rotation-breaking control device is controlled to increase the flow rate of the incoming airflow until the silicon powder particle size collected by the silicon powder detector is within the target value range.

10. The fluidized bed control method according to any one of claims 7 to 9, characterized in that: The fluidized bed control system further comprises a second barometer for monitoring the air pressure in the man-shaped tube; The method further comprises: acquiring in real time first pressure data in the jacket collected by the pressure monitoring device; In response to detecting an abnormal rise in the first pressure data, an alarm prompt of abnormal jacket pressure is displayed, and the nitrogen filling system is controlled to fill nitrogen into the jacket until the first pressure data is greater than the second pressure data collected by the second barometer and the difference is a first preset value.

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