Reaction device for preparing particles and method for preparing particles

Abstract

The present invention discloses a reaction device for preparing particles and a method for preparing particles, which relates to the technical field of gas-phase to solid-phase deposition for preparing particles. The reaction device for preparing particles includes: a reaction housing having a raw material gas inlet, a gas outlet, a particle inlet, and a particle outlet, and at least one reaction zone is formed in the reaction housing; at least one tray disposed in the reaction zone and having a preset angle with the horizontal plane, and the tray can enable the particles entering from the particle inlet to roll or slide downward on the tray to the particle outlet. This application can enable all particles to contact and react with the raw material gas under a substantially constant condition, so as to obtain high-purity and high-performance particle materials.

Description

Technical Field

[0001] The present invention relates to the technical field of gas-to-solid deposition for preparing particles, and particularly to a reaction device for preparing particles and a method for preparing particles. Background Art

[0002] In modern industrial production, the demand for particulate materials such as elements like silicon, nickel, magnesium, and titanium, or compounds such as silicon nitride, silicon carbide, silicon oxide, and silicon monoxide is increasing. At the same time, the requirements for the properties of the particles are becoming more and more stringent. For example, particulate materials need to meet requirements such as high purity, moderate and uniform particle size, low production cost of the particulate material, and the ability to achieve large-scale continuous production. The preferred reactor for traditional production of particulate materials generally uses a fluidized bed reactor, which uses selected raw material gases to carry out processes such as thermal decomposition or reduction, oxidation or nitridation in the reactor, so that the target elemental substances in the raw material gases are continuously deposited on the surface of the particle seeds. Eventually, after the particles reach the set size, they are collected to become the required particulate material. Common reaction processes include: thermal decomposition of chlorosilane to prepare polysilicon, and the reaction formula is as follows: SiHCl 3 +H 2 ---Si + HCl + SiCl 4 ; carbonylation purification, such as the decomposition of nickel carbonyl to produce nickel, and its reaction formula is as follows: Ni(CO) 4 ---Ni + CO; decomposition of silane to prepare high-purity polysilicon, and its reaction formula is as follows: SiH 4 ---Si + 2H 2

[0003] In a fluidized bed reactor, when preparing particulate materials, the raw material gases are used to suspend the solid particles. This operation has defects such as a large gas consumption and a large gas circulation volume. Moreover, it will cause a large amount of free space in the cavity of the fluidized bed reactor, and it is difficult to collect a large amount of dust generated by the decomposition of the raw material gases themselves. This will reduce the raw material utilization rate and increase the cost. The fluidized bed is mainly used in the chemical industry for the catalytic reaction of solid catalysts on gases, and for chemical vapor deposition, it is only applicable to low-density small particles, and it is very difficult for high-density large particles. Secondly, the temperature change in the fluidized bed reactor is large, and the gas composition varies greatly. The temperature and gas concentration can differ by more than 50% in different regions, which will result in non-uniform internal composition of the product particles prepared. For example, for reaction particles using chlorosilane or silane as raw material gases, the contents of chlorine and hydrogen in the particles generated in different regions of the fluidized bed are completely different, and the values can differ by several times.

[0004] Similarly, for a reactor in which reaction raw material gas passes through a bed layer with particles, although larger particle materials can be produced, since the raw material gas needs to penetrate the particle layer, the reaction degree of particles at different layer depths with raw material gas at different concentrations is different. Therefore, there will also be a problem of uneven composition of the particles generated during the reaction. Summary of the Invention

[0005] In order to overcome the above defects of the prior art, the technical problem to be solved by the embodiments of the present invention is to provide a reaction device for preparing particles and a method for preparing particles, which can enable all particles to contact and react with the raw material gas under a basically constant condition, so as to obtain high-purity and high-performance particle materials.

[0006] The specific technical solution of the embodiments of the present invention is as follows:

[0007] A reaction device for preparing particles, the reaction device for preparing particles includes: a reaction housing having a raw material gas inlet, a gas outlet, a particle inlet, and a particle outlet, and at least one reaction zone is formed in the reaction housing; at least one tray disposed in the reaction zone and having a preset angle with the horizontal plane, and the tray can make the particles entering from the particle inlet roll or slide downward on the tray to the particle outlet.

[0008] Preferably, there are multiple reaction zones, and the multiple reaction zones are arranged in the vertical direction. The particle inlet is located in the uppermost reaction zone, and the particle outlet is located in the lowermost reaction zone. In one reaction zone, the raw material gas inlet and the gas outlet are located on the same side of the tray. Preferably, one side surface of the tray for supporting particles has multiple steps. Preferably, the upper end of the tray located below extends beyond the lower end of the tray located above by a certain length, so that the particles flowing down from the tray located above can be caught by the tray located below.

[0009] Preferably, the multiple trays are distributed in a zigzag shape or parallel distribution. The upper end of the tray in the reaction zone located below can receive the particles discharged from the lower end of the tray in the reaction zone located above. Preferably, a neutral or inert gas that does not participate in the reaction can be ejected from the upper surface of the tray to stir the particle bed layer, and the raw material gas can be ejected from the back surface of the tray to the upper surface of the tray in the next reaction zone.

[0010] Preferably, the reaction housing has an inner side wall and an outer side wall, and the reaction zone is formed between the inner side wall and the outer side wall, and the tray is wound around the reaction zone along a cylindrical helix.

[0011] Preferably, the trays in one of the reaction zones are symmetrically arranged in the horizontal direction. There are multiple reaction zones, and the multiple reaction zones are arranged in the vertical direction. The upper end of the tray in the reaction zone located below can receive the particles discharged from the lower end of the tray in the reaction zone located above.

[0012] Preferably, the trays in one of the reaction zones are in the shape of a conical surface or a parabolic surface. There are multiple reaction zones, and the multiple reaction zones are arranged in the vertical direction. The upper end of the tray in the reaction zone located below can receive the particles discharged from the lower end of the tray in the reaction zone located above.

[0013] Preferably, the reaction device for preparing particles further includes: a thermal management mechanism for controlling the temperature of the particles in the reaction zone, and the thermal management mechanism includes at least one of the following:

[0014] A heating element arranged in the reaction zone, and the heating element adopts one or more of combustion heating, induction heating, microwave heating, intense light heating, resistance heating, and rotary furnace heating methods;

[0015] When the material of the particles is a conductive material, the heating mechanism is an electrical output device capable of being electrically connected to the stacked particle bed layer;

[0016] The thermal management mechanism is located outside the reaction zone to heat the particles outside the reaction zone;

[0017] When the particles are formed by condensation from gas to solid, the function of the thermal management mechanism is cooling.

[0018] Preferably, the reaction device for preparing particles further includes: a particle transportation mechanism for transporting the particles discharged from the particle outlet to the particle inlet, and the particle transportation mechanism includes at least one of the following: a bucket elevator, a screw elevator, a vibrating elevator, a pneumatic conveyor; and / or

[0019] A gas-solid separation mechanism connected to the gas outlet, and the gas-solid separation mechanism is used for separating and collecting the powder in the reaction tail gas; and / or

[0020] A gas distributor arranged at the raw material gas inlet; and / or

[0021] A screening mechanism, and the screening mechanism is used for separating and collecting the particles with a required diameter in the particles in the reaction shell or the particles discharged from the particle outlet; and / or

[0022] Transition deposition prevention mechanism, the transition deposition prevention mechanism includes: an air curtain mechanism that can block between the particles and the inner wall of the reaction shell; or a sandwich mechanism for cooling or heating provided at the inner wall of the reaction shell.

[0023] A method for preparing particles using the reaction device described in any one of the above, comprising the following steps:

[0024] Add particle seeds into the reaction zone through the particle inlet of the reaction shell, so that the particle seeds form a continuously rolling stacked particle bed from top to bottom on the pallet in the reaction zone;

[0025] Heat the stacked particle bed to reach the temperature required for particle reaction;

[0026] Introduce raw material gas through the raw material gas inlet of the reaction shell, so that the raw material gas reacts and deposits on the particle seeds to form particle materials with the required diameter;

[0027] Screen the particles discharged from the particle outlet of the reaction shell to obtain particles with the required diameter and particles that do not meet the required diameter, and re-add the particles that do not meet the required diameter to the reaction zone through the particle inlet of the reaction shell.

[0028] Preferably, the method further includes the following steps:

[0029] Perform gas-solid separation on the reaction tail gas discharged from the gas outlet of the reaction shell to separate and collect the powder in the reaction tail gas; and / or

[0030] Introduce auxiliary gas into the reaction shell to form an air curtain that plays a blocking role between the inner wall of the reaction shell and the particles; and / or

[0031] Crush some of the particles with the required diameter to prepare particle seeds, and add the prepared particle seeds to the reaction zone through the particle inlet of the reaction shell; and / or

[0032] Put the particles with the required diameter into a reaction chamber containing raw material gas with a volume concentration of 0-10% for reaction to perform surface treatment on the particles; and / or

[0033] Preheat the raw material gas and / or auxiliary gas and / or particles entering the reaction shell with the waste heat of the reaction tail gas discharged from the gas outlet of the reaction shell.

[0034] The technical solution of the present invention has the following remarkable beneficial effects:

[0035] In the reaction device for preparing particles according to the embodiments of the present application, particle seeds are input from the particle inlet of the reaction housing. The particles entering the reaction housing have a certain layer thickness on the pallet in the reaction zone, and then roll or slide downward under the action of gravity. During the rolling process, the surface of the particles directly contacts and reacts with the raw material gas input from the raw material gas inlet into the reaction housing, so that the target material in the raw material gas is deposited on the surface of the particles, causing the particles to grow continuously. Since all the particles are in a continuously rolling state during the reaction, and the raw material gas in the reaction housing is located on one side of the pallet without passing through the bed layer and the pallet, all the particles can react under relatively constant conditions, thereby preparing a particle material with higher purity and uniformity. In the above manner, high-purity and consistent particle materials can be prepared efficiently, energy-savingly, stably in the long term, and safely and reliably.

[0036] Referring to the following description and the accompanying drawings, specific embodiments of the present invention are disclosed in detail, indicating the ways in which the principles of the present invention can be employed. It should be understood that the embodiments of the present invention are not limited in scope thereby. Within the spirit and terms of the appended claims, the embodiments of the present invention include many changes, modifications, and equivalents. Features described and / or illustrated for one embodiment can be used in the same or similar manner in one or more other embodiments, combined with the features in other embodiments, or replace the features in other embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure of the present invention in any way. Additionally, the shapes and proportional dimensions of the components in the drawings are only schematic and are used to assist in the understanding of the present invention, rather than specifically defining the shapes and proportional dimensions of the components of the present invention. Those skilled in the art can, under the teachings of the present invention, select various possible shapes and proportional dimensions according to specific circumstances to implement the present invention.

[0038] Figure 1 It is a schematic longitudinal sectional structure diagram in the first embodiment of the embodiments of the present invention;

[0039] Figure 2 It is a schematic structure diagram in the second embodiment of the embodiments of the present invention;

[0040] Figure 3 It is a schematic structure diagram in the third embodiment of the embodiments of the present invention;

[0041] Figure 4 It is a schematic structure diagram in the fourth embodiment of the embodiments of the present invention;

[0042] Figure 5Schematic diagram of the structure in the fifth implementation manner in the embodiments of the present invention;

[0043] Figure 6 Schematic diagram of the structure in the sixth implementation manner in the embodiments of the present invention;

[0044] Figure 7 Schematic diagram of the structure in the seventh implementation manner in the embodiments of the present invention;

[0045] Figure 8 Schematic diagram of the setting of the pallet in the embodiments of the present invention.

[0046] Reference numerals of the above drawings:

[0047] 1. Reaction housing; 11. Inner side wall; 12. Outer side wall; 2. Raw material gas inlet; 3. Gas outlet; 4. Particle inlet; 5. Particle outlet; 6. Reaction zone; 7. Pallet; 8. Storage device; 9. Collection device; 10. Particle transportation mechanism. Specific implementation manners

[0048] Combined with the description of the drawings and the specific implementation manners of the present invention, the details of the present invention can be understood more clearly. However, the specific implementation manners of the present invention described herein are only for the purpose of explaining the present invention and cannot be understood in any way as a limitation of the present invention. Under the teaching of the present invention, those skilled in the art can conceive any possible deformation based on the present invention, and these should all be regarded as belonging to the scope of the present invention. It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "mounted", "connected", and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can also be the communication inside two elements. It can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific situations. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation manner.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific implementation manners and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0050] In order to enable all particles to react under a substantially constant condition with the raw material gas, so as to obtain high-purity and high-performance particle materials, a reaction device for preparing particles is proposed in this application. Figure 1 It is a schematic longitudinal sectional structure diagram in the first implementation mode in the embodiment of the present invention, as Figure 1 shown, the reaction device for preparing particles includes: a reaction housing 1 having a raw material gas inlet 2, a gas outlet 3, a particle inlet 4 and a particle outlet 5, and at least one reaction zone 6 is formed in the reaction housing 1; at least one tray 7 disposed in the reaction zone 6 and having a preset angle with the horizontal plane, and the tray 7 can make the particles entering from the particle inlet 4 roll or slide downward on the tray 7 to the particle outlet 5.

[0051] In the reaction device for preparing particles in the embodiment of this application, the particle seeds are input from the particle inlet 4 of the reaction housing 1. The particles entering the reaction housing 1 have a certain layer thickness on the tray 7 in the reaction zone 6, and then roll downward under the action of gravity. During the rolling process, the surface of the particles directly contacts and reacts with the raw material gas input from the raw material gas inlet 2 into the reaction housing 1, so that the target material in the raw material gas is deposited on the surface of the particles, causing the particles to grow continuously. Since all particles are in a rolling state during the reaction, and the raw material gas in the reaction housing 1 is located on one side of the tray 7 without passing through the bed layer and the tray 7, it is possible to make all particles carry out contact reactions under relatively constant conditions, thereby preparing particle materials with higher purity and being single. Through the above method, it is possible to achieve efficient energy saving, long-term stability, safe and reliable preparation of high-purity and good-consistency particle materials.

[0052] In order to better understand the reaction device for preparing particles in this application, the following will further explain and illustrate it. As Figure 1As shown, in the first embodiment, the reaction device for preparing particles includes: a reaction housing 1 having a raw material gas inlet 2, a gas outlet 3, a particle inlet 4, and a particle outlet 5. At least one reaction zone 6 is formed in the reaction housing 1. When there are multiple reaction zones 6, the multiple reaction zones 6 are arranged in the vertical direction, and multiple trays 7 are distributed in a zigzag shape or in parallel. The upper end of the tray 7 in the lower reaction zone 6 can receive the particles discharged from the lower end of the tray 7 in the upper reaction zone 6. When the multiple trays 7 are distributed in parallel, the tray 7 in the lower reaction zone 6 and the tray 7 in the upper reaction zone 6 can transfer particulate material through a conveying mechanism formed by two parallel flat plates. When the multiple trays 7 are distributed in a zigzag shape, the upper end of the tray 7 in the lower reaction zone 6 is located at the tail of the tray 7 in the upper reaction zone 6, so as to directly receive the particles rolling down from the tray 7 in the upper reaction zone 6. The tray 7 in the reactor has a preset angle with the horizontal plane. By controlling the size of the preset angle, the rolling speed of particles of different shapes and sizes can be effectively controlled. The preset angle can be a constant angle or a variable angle, that is, the slopes at different positions of the tray 7 are different. In order to make the rolling speed of the particles on the tray 7 slower, the side surface of the tray 7 supporting the particles has multiple steps with smaller sizes, so as to slow down the rolling speed of the particles.

[0053] As Figure 1 shown, the particle inlet 4 of the reaction housing 1 is located in the uppermost reaction zone 6, specifically above the upper end of the tray 7 in the uppermost reaction zone 6, so that the particles input from the particle inlet 4 fall onto the upper end of the tray 7, and then the particles roll down from top to bottom on the tray 7. The particle outlet 5 is located in the lowermost reaction zone 6, so that the particles in the reaction housing 1 are discharged from the reaction housing 1 under the action of gravity. In one reaction zone 6, the raw material gas inlet 2 and the gas outlet 3 are located on the same side of the tray 7, so that the raw material gas input from the raw material gas inlet 2 can directly contact the particle surface, the particle surface is deposited, and the particles are continuously grown.

[0054] In this embodiment, the number of reaction zones 6 is 3. The raw material gas inlet 2 of the reaction housing 1 is located at the reaction housing 1 at the lower end of the tray 7 in the reaction zone 6. The gas flow of the gas input from the raw material gas inlet 2 is parallel to the particle flow direction on the tray 7. The gas outlet 3 is located above the tray 7 in the reaction zone 6. A storage device 8 for storing particles and controlling particle output can be installed at the particle inlet 4 according to actual needs. At the same time, a collection device 9 and a screening device (not shown) for collecting particles can also be installed below the particle outlet 5 or below the tray 7 in the lowermost reaction zone 6.

[0055] Figure 2 is a schematic structural diagram in the second embodiment in the embodiments of the present invention. As Figure 2As shown, in this embodiment, the raw material gas inlet 2 in the reaction housing 1 can be located above the middle of the pallet 7 and perpendicular to the surface of the pallet 7. The raw material gas can be input into the interior of the reaction housing 1 by a gas distributor, so that the gas can be more evenly sprayed onto the particles on the pallet 7 from multiple angles. There can be two gas outlets 3 in the reaction housing 1. One gas outlet 3 is located at the lower end of the pallet 7 in the reaction zone 6, and the other gas outlet 3 is located at the upper end of the pallet 7 in the reaction zone 6 or above the upper end of the pallet 7. The two gas outlets 3 are respectively located on the upper and lower sides of the raw material gas inlet 2, which can effectively discharge the gas generated in the reaction housing 1 and reduce the probability of the raw material gas being discharged. It should be noted that other structures in this embodiment can refer to the reaction devices for preparing particles in other embodiments.

[0056] Figure 3 This is a schematic structural diagram in the third embodiment of the present invention. As Figure 3 shown, in this embodiment, multiple pallets 7 are distributed in a zigzag shape. The upper end of the pallet 7 in the lower reaction zone 6 is located at the tail of the pallet 7 in the upper reaction zone 6, so as to directly receive the particles rolling down from the pallet 7 in the upper reaction zone 6. The raw material gas inlet 2 in the reaction housing 1 can be located on the left and right sides of the reaction housing 1, and the gas outlet 3 in the reaction housing 1 can also be located on the left and right sides of the reaction housing 1. The raw material gas inlets 2 and gas outlets 3 located on the left and right sides of the reaction housing 1 respectively input raw material gas and output reaction tail gas to different reaction zones. It should be noted that other structures in this embodiment can refer to the reaction devices for preparing particles in other embodiments.

[0057] Figure 4 This is a schematic structural diagram in the fourth embodiment of the present invention. As Figure 4As shown, in this embodiment, a plurality of trays 7 are arranged in a reaction zone 6 at a preset angle with the horizontal plane. The plurality of trays 7 in one reaction zone 6 are parallel to each other and arranged in sequence along the horizontal direction. There are a plurality of reaction zones 6, and the plurality of reaction zones 6 are arranged vertically. The particle inlet 4 is located in the uppermost reaction zone 6, and the particle outlet 5 is located in the lowermost reaction zone 6. The matching trays 7 in different reaction zones 6 are distributed in a zigzag shape or parallel. For example, there are 3 reaction zones 6 arranged in the reaction housing 1, and 3 trays 7 are arranged in each reaction zone 6 at a preset angle with the horizontal plane. On each tray 7, the particles entering from the particle inlet 4 can roll down on the tray 7 from top to bottom to the particle outlet 5. Through the above method, multiple tracks for rolling particles can be formed in one reaction zone 6 of one reaction housing 1, so as to achieve the purpose of saving space. The raw material gas can be sprayed from the back of the tray onto the particle layer on the next tray. It should be noted that other structures in this embodiment can refer to the reaction device for preparing particles in other embodiments.

[0058] Figure 5 It is a schematic structural diagram in the fifth embodiment of the embodiment of the present invention. As Figure 5 shown, in this embodiment, the reaction housing 1 at least includes an inner side wall 11 and an outer side wall 12. A reaction zone 6 is formed between the inner side wall 11 and the outer side wall 12. A tray 7 is arranged in the reaction zone 6. The tray 7 is wound around the reaction zone 6 along a cylindrical helix. One side of the tray 7 is connected and abutted against the inner side wall 11, and the other side of the tray 7 is connected and abutted against the outer side wall 12. The particle inlet 4 and the gas outlet 3 can be located at the upper end of the reaction housing 1. The particle inlet 4 is matched with the upper end of the tray 7 of the cylindrical helix so that the particles input from the particle inlet 4 fall on the tray 7. The raw material gas inlet 2 and the particle outlet 5 are located at the tail end of the tray 7 at the lower end of the reaction housing 1. The raw material gas inlet 2 can be specifically arranged on the upper side surface of the tail end of the tray 7. The raw material gas enters the reaction housing 1 from the raw material gas inlet 2 at the tail end of the tray 7 at the lower end of the reaction housing 1. The particles are transported from the particle inlet 4 at the upper end of the reaction housing 1 to the tray 7. The particles roll down along the cylindrical helix on the tray 7, and the raw material gas flows upward along the cylindrical helix. During this process, the target material in the raw material gas is deposited on the particles, and the particles are continuously grown. The generated tail gas is led out of the reaction housing 1 through the gas outlet 3 at the upper end of the reaction housing 1. The reacted particles are discharged from the reaction housing 1 through the particle outlet 5 located at the lower end of the reaction housing 1.

[0059] Optionally, the raw material gas inlet 2 can also be located on the side wall of the coil pipe with the same winding shape as the pallet 7, and the raw material gas is ejected from the side wall of the pipe. The coil pipe can be located at the back, above or on the side of each pallet 7, so that the upper side of the pallet 7 or the back of the upper pallet 7 is filled with uniformly distributed raw material gas, so as to achieve the reaction of all particles and the raw material gas under a basically constant condition.

[0060] In a preferred embodiment, a plurality of pallets 7 wound along a cylindrical helix can be arranged in the reaction zone 6, and the plurality of pallets 7 are parallel to each other and arranged vertically. In this way, multiple channels similar to Figure 4 the tracks for the particles to roll down parallel to each other can be formed in a reaction shell 1, so as to achieve the purpose of saving space.

[0061] Figure 6 is a schematic structural diagram of the sixth embodiment in the embodiments of the present invention. As Figure 6 shown, in this embodiment, the pallets 7 in a reaction zone 6 are symmetrically arranged in the horizontal direction. For example, the cross-section of the pallet 7 can be V-shaped or inverted V-shaped. There are two pallets 7 with an inverted V-shaped cross-section, and there is a gap in the middle of the two pallets 7 so that the particles can fall from the middle of the pallet 7 into the next reaction zone 6. There can be multiple reaction zones 6, and the multiple reaction zones 6 are arranged vertically. The upper end of the pallet 7 in the reaction zone 6 located below can receive the particles discharged from the lower end of the pallet 7 in the reaction zone 6 located above. The raw material inlet of the reaction shell 1 is located in the middle of the upper end of the reaction shell, so that the particles can be divided into two parts during the falling and conveying process, one part rolls to the left side of the pallet 7, and the other part rolls to the right side of the pallet 7. In the reaction zone 6 where the cross-section of the pallet 7 is inverted V-shaped, the raw material gas inlet 2 can be located on the left and right side walls of the reaction shell 1 at the lower end of the pallet 7, and the air flow input from the raw material gas inlet 2 is parallel to the pallet 7. In the reaction zone 6 where the cross-section of the pallet 7 is V-shaped, the raw material gas inlet 2 can be located on the side wall of the pipe in the middle above the pallet 7. The pipe extends in a direction perpendicular to the paper surface, and there can be multiple openings on the side wall of the pipe so that the gas in the pipe can be sprayed towards the particles on the pallet 7 from multiple angles. The gas outlet 3 can be located at the upper end of the reaction shell 1 and on the left and right side walls of the reaction shell 1, and specifically can be located on the reaction shell 1 above the pallet 7 in the reaction zone 6 and away from the raw material gas inlet 2.

[0062] Figure 7 is a schematic structural diagram of the seventh embodiment in the embodiments of the present invention. As Figure 7As shown, in this embodiment, the support plate 7 in one reaction zone 6 is in the shape of a cone or a parabola, and the horizontal cross-section of the reaction shell 1 is circular. There may be multiple reaction zones 6, and the multiple reaction zones 6 are arranged in the vertical direction. The upper end of the support plate 7 of the reaction zone 6 located at the bottom can receive the particles discharged from the lower end of the support plate 7 of the reaction zone 6 located at the top. The cone or parabola of the support plates 7 in the adjacent reaction zones 6 are oriented in opposite directions. The lower end of the support plate 7 with the pointed corner of the cone or parabola facing downward in the reaction zone 6 is provided with an opening, which enables the particles to fall from the middle of the support plate 7 into the next reaction zone 6. In the reaction zone 6 with the pointed corner of the cone or parabola of the support plate 7 facing upward, the raw gas inlet 2 can be located on the side wall of the reaction shell 1 at the lower end of the support plate 7. In the reaction zone 6 with the conical or parabolic surface of the support plate 7 facing downward, the raw gas inlet 2 can be located in the middle of the upper part of the support plate 7, and the gas can be sprayed at multiple angles toward the particles on the support plate 7 through a sphere with an opening or the like. The gas outlet 3 can be located in the middle of the upper end of the reaction shell 1 and on the side wall of the reaction shell 1. When the gas outlet 3 is located on the side wall of the reaction shell 1, it can be located on the reaction shell 1 above the support plate 7 in the reaction zone 6 and away from the raw gas inlet 2.

[0063] In the above-mentioned various embodiments, Figure 8 Schematic diagram of the support plate arrangement in an embodiment of the present invention, as shown in FIG. Figure 8 As shown, in a preferred embodiment, the upper end of the support plate 7 located at the bottom is longer than the lower end of the support plate 7 located at the top, so that the particles flowing down from the support plate 7 located at the top can be caught by the support plate 7 located at the bottom. Both ends of the support plate 7 are not in contact with the inner wall of the reactor shell 1 as much as possible to prevent the particle flow from directly contacting the inner wall of the reactor shell 1. All surfaces of the particles in contact with it during the circulation process are as much as possible composed of the target material itself or other materials that do not introduce pollution.

[0064] In the above-mentioned various embodiments, the reaction device for preparing particles may further include: a thermal management mechanism for controlling the temperature of the particles in the reaction zone 6, and the thermal management mechanism can enable the particles to react under the same preset temperature condition. The thermal management mechanism may be located inside or outside the reaction housing 1. The selection of the thermal management mechanism can be determined according to the specific reaction of the particles. For example, the thermal management mechanism at least includes one of the following: a heating element arranged in the reaction zone 6, and the heating element adopts one or more of combustion heating, induction heating, microwave heating, intense light heating, resistance heating, and rotary furnace heating methods; when the material of the particles is a conductive material, the thermal management mechanism is an electrical output device capable of being electrically connected to the stacked particle bed layer; the thermal management mechanism is located outside the reaction zone 6 to heat the particles outside the reaction zone 6. When the particles are formed by condensation from gas phase to solid phase, the function of the thermal management mechanism is cooling. In addition to the pallet itself, the turning pipeline between the two pallets 7 can also be used as a thermal management unit for the particles.

[0065] In the above-mentioned various embodiments, the reaction device for preparing particles further includes: a particle transportation mechanism 10 for transporting the particles discharged from the particle outlet 5 to the particle inlet 4, and the particle transportation mechanism 10 at least includes one of the following: a bucket elevator, a screw elevator, a vibrating elevator, a pneumatic conveyor, etc. In this application, no restrictions are imposed on the type of the particle transportation mechanism 10, as long as it can transport the particles discharged from the particle outlet 5 to the particle inlet 4. Through the particle transportation mechanism 10, the particles can circulate and roll on the pallet 7 in the reaction housing 1, so that they continuously react with the raw material gas until the size of the particles meets the requirements. This structure can effectively reduce the size scale of the reaction housing 1.

[0066] In the above-mentioned various embodiments, the inner wall of the reaction housing 1, the surface layer of the pallet 7 that holds up the particles, and all components that can come into contact with the particles can be made of the same material as the prepared particles or materials that do not contaminate the particles. For example, for producing polysilicon materials, high-purity silicon, high-purity silicon carbide, high-purity silicon nitride, quartz, or graphite and other materials that will not diffuse impurities into the reaction housing 1 at high temperatures can be used. In this way, the contamination of the particle by the material of the reaction housing 1 can be reduced or avoided, and at the same time, it has sufficient mechanical strength under high-temperature conditions.

[0067] In the above-mentioned various embodiments, the pallet may include multiple parts, for example, including: a surface layer for lifting particles, a heat insulation layer, a temperature control layer, a strengthening layer, a back layer, and so on. The surface layer may preferably be the target material itself, which is mainly used to lift particles and cause as little pollution to the particles as possible. The heat insulation layer is used to prevent the heat of the surface layer from propagating in the direction away from the particles. The temperature control layer can be used to control the temperature of the back surface of the pallet, so that the back surface of the pallet does not deposit too quickly. The temperature control layer can be a heat conduction pipe network or a heat pipe network arranged in the pallet, etc. The strengthening layer is used to enhance the mechanical strength of the entire pallet, and it can be a layer of material with relatively high strength for support or some reinforcing ribs, etc. The back layer can also be made of the same material as the prepared particles or a material that does not pollute the particles. Optionally, the raw material gas can be sprayed from the back surface of the pallet to the particle layer on the upper surface of the adjacent pallet below through the pipes arranged inside the pallet. Similarly, the non-reactive neutral or inert gas is ejected from the front surface of the pallet through the pipes installed in the pallet by the nozzle to stir the particle bed layer.

[0068] In the above-mentioned various embodiments, the reaction device for preparing particles may further include: a gas-solid separation mechanism connected to the gas outlet 3, and the gas-solid separation mechanism is used to separate and collect the powder in the reaction tail gas. The reaction tail gas discharged from the gas outlet 3 passes through the gas-solid separation mechanism with a densely packed particle material bed layer to collect the powder material in the reaction tail gas, and the filling rate of the densely packed particle material bed layer is more than 20%. Of course, the reaction tail gas after separating the powder material can also be separated according to the gas components, and the separated raw material gas is transported back to the reaction shell 1 through the raw material gas inlet 2 for recycling.

[0069] In order to make the free space between the particle materials in the packed particle bed layer smaller, thereby increasing the filling rate, operations such as pressurization, spouted bed, and downward moving bed can be adopted. For example, specific measures can increase the particle packing density through a moving bed (vertical, horizontal, inclined), reduce the free space, thereby reducing the generation of gas-phase powder and accelerating the polymerization of powder to particles.

[0070] In the above-mentioned various embodiments, the reaction device for preparing particles may further include: a screening mechanism, which is used to separate and collect the particles with a required diameter in the particles in the reaction housing 1 or the particles discharged from the particle outlet 5. For example, the screening mechanism may be connected to the particle outlet 5 of the reaction housing 1, and it separates and collects the particles with a required diameter in the particles discharged from the particle outlet 5 of the reaction housing 1. The particles that do not meet the required diameter can be transported to the particle transport mechanism 10, and the particle transport mechanism 10 transports the particles that do not meet the required diameter to the particle inlet 4 of the reaction housing 1. Of course, the screening mechanism may also be arranged in the reaction housing 1, which directly screens out the particles that do not meet the required diameter and the particles that meet the required diameter, and discharges them from the particle outlet 5 of the reaction housing 1 respectively. The discharged particles that do not meet the required diameter are directly transported to the particle inlet 4 of the reaction housing 1 again through the particle transport mechanism 10.

[0071] In the above-mentioned various embodiments, the reaction device for preparing particles may further include: a particle seed preparation mechanism, which is used to fragment some of the prepared particles to obtain small particle materials. On the one hand, the small particle materials can be used as the densely packed particle material bed layer in the gas-solid separation mechanism. On the other hand, they can also be transported to the particle inlet 4 of the reaction housing 1 as particle seeds to supplement the number of particles in the reaction housing 1 to maintain the dynamic balance of the particles in the reaction housing 1. For example, the seed preparation mechanism can adopt a device such as a grinder that can crush large particles.

[0072] In the above-mentioned various embodiments, the reaction device for preparing particles may further include: a surface finishing mechanism for treating the surface of the initial product of the particles with a required diameter obtained by screening by the screening mechanism. After passing through the surface finishing mechanism, particle materials with a smooth surface can be obtained. The particle materials after surface treatment are cooled, collected, packaged or directly transported to the downstream production section. The surface finishing mechanism can be a reaction chamber containing a raw material gas with a volume concentration of 0-10%. The concentration of the raw material gas can be changed according to the actual type of particles and the reaction conditions. No limitation is made in this application. When there is no raw material gas in the reaction chamber (i.e., containing 0% of the raw material gas, a neutral or inert gas), the initial products of each particle material become smooth by rubbing against each other; when there is a raw material gas in the reaction chamber, in addition to the mutual rubbing between the initial products of each particle material, the decomposed low-concentration raw material gas is deposited on the surface of the initial product of the particle material, further making the surface of the initial product of the particle material smooth.

[0073] In the above-mentioned various embodiments, the reaction device for preparing particles may further include: a preheating mechanism, which may be a heat exchanger, and is disposed inside or outside the reaction shell 1. It uses the waste heat in the reaction tail gas to preheat the raw material gas and / or auxiliary gas and / or particles entering the reaction shell 1. By the above method, the reaction waste heat is effectively utilized and the production cost is reduced.

[0074] In the above-mentioned various embodiments, the reaction device for preparing particles may further include: a transition deposition prevention mechanism, which includes: an air curtain mechanism that can play a blocking role between the particles and the inner wall of the reaction shell 1; or a cooling or heating sandwich mechanism disposed at the inner wall of the reaction shell 1. The air curtain mechanism may be a plurality of ventilation ports disposed on the inner wall of the reaction shell 1, and the arrangement of the plurality of ventilation ports can make the introduced auxiliary gas form an air curtain along the inner wall of the reaction shell 1, so that there is a certain blocking effect between the particles in the reaction shell 1 and the inner wall of the reaction shell 1. At the same time, it can also achieve the purpose of diluting the raw material gas and stirring the stacked particle bed formed on the tray 7 to prevent caking, thereby preventing the deposition of solid materials at the raw material gas inlet 2 and the inner wall of the reaction shell 1. Generally speaking, the auxiliary gas may be an inert or non-reactive gas. The cooling or heating sandwich mechanism can perform thermal management on the inner wall of the reaction shell 1, such as controlling the inner wall temperature by heating or passing a cooling water jacket to achieve the effect of reducing deposition.

[0075] The reaction device for preparing particles in this application can be applicable to particles that can be obtained by deposition and / or condensation, including but not limited to silicon particles, nickel particles, magnesium particles, silicon nitride particles, silicon carbide particles, silicon oxide particles, and silicon monoxide particles, etc.

[0076] In this application, a method for preparing particles is also proposed. The method for preparing particles may include the following steps:

[0077] Add particle seeds into the reaction zone 6 through the particle inlet 4 of the reaction shell 1, so that the particle seeds form a stacked particle bed that continuously rolls from top to bottom on the tray 7 in the reaction zone 6. The covering thickness of the particles in the stacked particle bed may be more than one time, more than two times, more than 3 times, more than 4 times, or more than 5 times the average particle diameter, etc. Preferably, it is a closely packed particle bed evenly covering the tray without leaving any place where the tray is exposed.

[0078] The stacked particle bed is heated to reach the temperature required for particle reaction. One or more of the above thermal management mechanisms can be selected to heat or cool the stacked particle bed according to the type and properties of the particles. For example, when the particles are nickel particles, during the heating process, the stacked nickel particle bed can be connected to the power supply electrodes, that is, a voltage is applied to the stacked nickel particle bed. Since the nickel particles in the stacked nickel particle bed are in contact with each other and conduct electricity, the nickel particles can be energized to generate heat by their own resistance for heating, so that the stacked particle bed reaches the thermal decomposition temperature of nickel carbonyl. Similarly, when producing granular polysilicon, the part of the upper surface of the pallet that supports the granular silicon bed can be composed of high-purity polysilicon or polysilicon plates. By applying a voltage to both ends of the plate, each plate becomes a resistance heating unit. At the same time, the granular bed on the plate will also become part of the self-conductive heating. When the particles are formed by condensation from gas phase to solid phase, the role of the thermal management mechanism is cooling.

[0079] Raw material gas is introduced through the raw material gas inlet 2 of the reaction shell 1 so that the raw material gas reacts and deposits on the particle seeds to form particle materials with the required diameter.

[0080] The particles discharged from the particle outlet 5 of the reaction shell 1 are screened to obtain particles with the required diameter and particles that do not meet the required diameter. The particles that do not meet the required diameter are re-added to the reaction zone 6 through the particle inlet 4 of the reaction shell 1.

[0081] The reaction tail gas discharged from the gas outlet 3 of the reaction shell 1 is subjected to gas-solid separation to separate and collect the powder in the reaction tail gas.

[0082] Auxiliary gas is introduced into the reaction shell 1 through the air curtain mechanism of a plurality of ventilation ports provided on the inner wall of the reaction shell 1 to form an air curtain that plays a blocking role between the inner wall of the reaction shell 1 and the particles.

[0083] Part of the particles with the required diameter are crushed by the particle seed preparation mechanism to prepare particle seeds, and the prepared particle seeds are added to the reaction zone 6 through the particle inlet 4 of the reaction shell 1, so as to supplement the number of particles in the reaction shell 1 and maintain the dynamic balance of the particles in the reaction shell 1.

[0084] The particles with the required diameter are placed in a reaction chamber containing raw material gas with a volume concentration of 0-10% by the surface finishing mechanism for reaction to perform surface treatment on the particles, so that the surface of the initial product of the particle material becomes smooth.

[0085] The preheating mechanism uses the waste heat of the reaction tail gas discharged from the gas outlet 3 of the reaction shell 1 to preheat the raw material gas and / or auxiliary gas and / or particles entering the reaction shell 1.

[0086] The reaction device for preparing particles and the method for preparing particles provided by the present application have the following main advantages compared with the currently adopted fluidized bed process for producing particulate materials:

[0087] 1. After the raw materials are fed into the reaction shell 1, a particle bed layer that rolls downward from top to bottom is formed on the pallet 7. In this way, without the need to set up a gas distributor, the raw material gas and the particulate material seeds can be fully contacted and reacted under stable reaction conditions, overcoming the problem of uneven particle composition generated by the different reaction degrees of particles at different layer depths and the raw material gas with different concentrations in the fluidized bed process. At the same time, the stable and continuous operation of the reaction device can also be achieved.

[0088] 2. The raw material gas in the reaction device of the present application sweeps over the surface of the particle bed layer on the pallet 7, or the raw material gas is sprayed onto the particle bed layer at multiple angles without passing through the bed layer, so that the reaction proceeds under stable conditions.

[0089] Each of the above-described embodiments in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. All articles and reference materials disclosed, including patent applications and publications, are incorporated herein by reference for various purposes. The term "consisting essentially of" describing a combination should include the identified elements, components, parts or steps and other elements, components, parts or steps that do not substantially affect the basic novel features of the combination. Using the terms "comprising" or "including" to describe the combination of elements, components, parts or steps herein also contemplates embodiments consisting essentially of these elements, components, parts or steps. Here, by using the term "may", it is intended to indicate that any attribute described as "may" included is optional. Multiple elements, components, parts or steps can be provided by a single integrated element, component, part or step. Alternatively, a single integrated element, component, part or step can be divided into multiple separate elements, components, parts or steps. The disclosure of "a" or "an" for an element, component, part or step does not mean to exclude other elements, components, parts or steps.

[0090] The above are only several embodiments of the present invention. Although the disclosed embodiments are as above, the above content is only an embodiment adopted for the convenience of understanding the present invention and is not used to limit the present invention. Any person skilled in the art of the present invention can make any modifications and changes in the form and details of the embodiments without departing from the spirit and scope disclosed by the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A reaction device for preparing particles, characterized in that, the reaction device for preparing particles includes: a reaction housing having a raw material gas inlet, a gas outlet, a particle inlet and a particle outlet, and at least one reaction zone is formed in the reaction housing; at least one tray disposed in the reaction zone and having a preset angle with the horizontal plane, and the tray can make the particles entering from the particle inlet roll or slide downward on the tray to the particle outlet; in one of the reaction zones, the raw material gas inlet and the gas outlet are located on the same side of the tray, and one side surface of the tray for supporting particles has a plurality of steps; the raw material gas inlet of the reaction housing is located at the reaction housing at the lower end of the tray in the reaction zone, the gas flow of the gas input from the raw material gas inlet is parallel to the particle flow direction on the tray, and the gas outlet is located above the tray in the reaction zone; the raw material gas sweeps across the surface of the particle bed on the tray; the raw material gas inlet in the reaction housing is located above the middle of the tray and perpendicular to the surface of the tray, and the raw material gas is input into the interior of the reaction housing by a gas distributor so that the gas can be sprayed onto the particles on the tray at multiple angles, and the raw material gas is sprayed onto the particle bed at multiple angles without passing through the bed; an inert gas that does not participate in the reaction can be ejected from the upper surface of the tray to stir the particle bed, and the raw material gas can be sprayed onto the upper surface of the tray in the next reaction zone from the back surface of the tray; there are multiple reaction zones, and the multiple reaction zones are arranged in the vertical direction, the particle inlet is located in the uppermost reaction zone, the particle outlet is located in the lowermost reaction zone, and the upper end of the tray located below extends beyond the lower end of the tray located above by a certain length so that the particles flowing down from the tray located above can be caught by the tray located below.

2. The reaction device for preparing particles according to claim 1, characterized in that, the multiple trays are distributed in a zigzag shape or in parallel, and the upper end of the tray in the reaction zone located below can receive the particles discharged from the lower end of the tray in the reaction zone located above.

3. The reaction device for preparing particles according to claim 1, characterized in that, the reaction housing has an inner wall and an outer wall, the reaction zone is formed between the inner wall and the outer wall, and the tray is wound around the reaction zone along a cylindrical helix.

4. The reaction device for preparing particles according to claim 1, characterized in that, the tray in one of the reaction zones is symmetrically arranged in the horizontal direction, there are multiple reaction zones, and the multiple reaction zones are arranged in the vertical direction, and the upper end of the tray in the reaction zone located below can receive the particles discharged from the lower end of the tray in the reaction zone located above.

5. The reaction device for preparing particles according to claim 1, characterized in that, The pallet in one of the reaction zones is in the shape of a conical surface or a paraboloid surface. There are multiple reaction zones, and the multiple reaction zones are arranged vertically. The upper end of the pallet in the reaction zone located below can receive the particles discharged from the lower end of the pallet in the reaction zone located above.

6. The reaction device for preparing particles according to claim 1, wherein, the reaction device for preparing particles further includes: a thermal management mechanism for controlling the temperature of the particles in the reaction zone, and the thermal management mechanism includes at least one of the following: a heating element arranged in the reaction zone, and the heating element adopts one or more of combustion heating, induction heating, microwave heating, and resistance heating; when the material of the particles is a conductive material, the thermal management mechanism is an electrical output device capable of being electrically connected to the stacked particle bed; the thermal management mechanism is located outside the reaction zone to heat the particles outside the reaction zone; when the particles are formed by condensation from gas phase to solid phase, the role of the thermal management mechanism is cooling.

7. The reaction device for preparing particles according to claim 1, wherein, the reaction device for preparing particles further includes: a particle transportation mechanism for transporting the particles discharged from the particle outlet to the particle inlet, and the particle transportation mechanism includes at least one of the following: a bucket elevator, a screw elevator, a vibrating elevator, a pneumatic conveyor; and / or a gas-solid separation mechanism connected to the gas outlet, and the gas-solid separation mechanism is used for separating and collecting the powder in the reaction tail gas; and / or a gas distributor arranged at the raw material gas inlet; and / or a screening mechanism for separating and collecting the particles with a diameter meeting the requirements in the particles in the reaction shell or the particles discharged from the particle outlet; and / or a transition deposition prevention mechanism, and the transition deposition prevention mechanism includes: an air curtain mechanism capable of blocking between the particles and the inner wall of the reaction shell or a cooling or heating sandwich mechanism arranged at the inner wall of the reaction shell.

8. A method for preparing particles by using the reaction device according to any one of claims 1 to 7, wherein, it includes the following steps: adding particle seeds into the reaction zone through the particle inlet of the reaction shell, so that the particle seeds form a stacked particle bed that continuously rolls from top to bottom on the pallet in the reaction zone; heating the stacked particle bed to reach the temperature required for particle reaction; introducing raw material gas through the raw material gas inlet of the reaction shell, so that the raw material gas reacts and deposits on the particle seeds to form particle materials with a diameter meeting the requirements; screening the particles discharged from the particle outlet of the reaction shell to obtain particles with a diameter meeting the requirements and particles with a diameter not meeting the requirements, and re-adding the particles with a diameter not meeting the requirements into the reaction zone through the particle inlet of the reaction shell.

9. The method for preparing particles according to claim 8, wherein, it further includes the following steps: performing gas-solid separation on the reaction tail gas discharged from the gas outlet of the reaction shell to separate and collect the powder in the reaction tail gas; and / or Introduce auxiliary gas into the reaction housing to form an air curtain that acts as a barrier between the inner wall of the reaction housing and the particles; and / or Crush some of the particles that reach the required diameter to prepare particle seeds, and add the prepared particle seeds into the reaction zone through the particle inlet of the reaction housing; and / or Place the particles that reach the required diameter into a reaction chamber containing a raw material gas with a volume concentration of 0-10% for reaction to perform surface treatment on the particles; and / or Preheat the raw material gas and / or auxiliary gas and / or particles entering the reaction housing with the waste heat of the reaction tail gas discharged through the gas outlet of the reaction housing.

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