Gas supply system and gas supply method for producing nano silicon powder by silane CVD (Chemical Vapor Deposition) method

Abstract

The invention relates to the technical field of nano silicon production, in particular to a gas supply system and a gas supply method for producing nano silicon powder by a silane CVD (chemical vapor deposition) method, the gas supply system comprises a reaction kettle, the reaction kettle is provided with a gas inlet pipe and a heater, the heater is internally provided with a wavy reaction channel, and the inner wall of the reaction channel is provided with a heating plate; the first processor is located between the air inlet pipe and the heater, and the first processor comprises a main pipe and a branch pipe. When the device works, airflow enters the main pipe along the branch pipe and makes contact with the tangent flow guide conical ring, the airflow moves along the flow guide conical ring and forms spiral airflow extending towards the first end of the main pipe, the gas flowing speed is high, part of the airflow rubs with the inner wall of the main pipe, the temperature rises, and the preheated airflow enters the heater; and the preheated silane moves along the wavy reaction channel in the heater, and the heating plate on the inner wall of the reaction channel further heats the preheated silane, so that the heating time of the silane is shortened, and the temperature of the silane is prevented from being too high.

Description

Technical Field

[0001] The invention relates to the technical field of nano silicon production, and in particular to a gas supply system and a gas supply method for producing nano silicon powder by a silane CVD method. Background Art

[0002] Nano silicon refers to silicon particles with a particle size of nanometers, which have the characteristics of high purity, small particle size, and uniform distribution. Nano silicon powder is a new generation of optoelectronic semiconductor material with a wide gap energy semiconductor. It is also a high-power light source material. At the same time, nano silicon is also a functional filler with excellent performance.

[0003] According to the publication (announcement) number CN203794640U, the publication (announcement) date is 2014-08-27, a device for producing nano-scale high-purity silicon powder by thermal decomposition of silane is disclosed, which includes a silane thermal decomposition system, a silicon powder filtering and collecting system, and an exhaust gas recovery and processing system. The silane decomposition system includes a reaction gas silane pipeline, a reaction gas hydrogen pipeline, a proportioning buffer tank, a silane tubular reactor, and an exhaust gas cooler. The reaction gas silane pipeline and the reaction gas hydrogen pipeline are connected to the proportioning buffer tank, and the proportioning buffer tank, the silane tubular reactor, and the exhaust gas cooler are connected in sequence. The silicon powder filtering and collecting system includes a hydrogen backwash filter pipeline, a primary silicon powder filter, a secondary silicon powder filter, a primary silicon powder collecting bin, a secondary silicon powder collecting bin, a vacuum pump, a primary silicon powder outlet pipeline, a secondary silicon powder outlet pipeline, one end of the hydrogen backwash filter pipeline is connected to the reaction gas hydrogen pipeline, and the other end of the hydrogen backwash filter pipeline is respectively connected to the primary silicon powder filter and the secondary silicon powder filter, the tail gas cooler, the primary silicon powder filter, the secondary silicon powder filter are connected in sequence, and the primary silicon powder filter, the primary silicon powder collecting bin, and the primary silicon powder outlet pipeline are connected in sequence. The device is suitable for the production of industrial nanometer-level high-purity silicon powder, all tail gas is recycled, there is no pollution emission, and it has the advantages of low investment and low cost.

[0004] In the prior art including the above patents, nano silicon powder is generally produced by thermal cracking of silane, and the thermal cracking of silane requires 400°C, but when the temperature reaches 600°C, silane will decompose to produce crystalline silicon. Most of the existing production equipment continuously heats silane to raise the temperature of silane to above 400°C, but the flow of gas is not uniform, which causes the temperature of some slower-flowing gases to be too high, even reaching above 600°C, and the crystalline silicon produced at this temperature will reduce the purity of the nano silicon produced by silane. Summary of the invention

[0005] The purpose of the present invention is to provide a gas supply system and a gas supply method for producing nano-silicon powder by a silane CVD method, aiming to solve the above-mentioned problems.

[0006] In order to achieve the above object, the present invention provides a gas supply system for producing nano-silicon powder by silane CVD method, comprising a reactor, wherein the reactor is provided with:

[0007] Intake pipe:

[0008] A heater, wherein a wavy reaction channel is arranged inside the heater, and a heating plate is arranged on the inner wall of the reaction channel;

[0009] The first processor is located between the intake pipe and the heater, and includes a main pipe and a branch pipe. A guide cone ring is provided in the middle of the main pipe. The branch pipe is perpendicular to the main pipe and its axis is tangent to the guide cone ring, wherein:

[0010] The high-speed airflow enters the main pipe along the branch pipe, moves along the guide cone ring and forms a spiral airflow extending toward the first end of the main pipe, and enters the heater for further heating after the airflow is heated by friction with the inner wall of the main pipe.

[0011] Preferably, a mixing chamber is provided between the air inlet pipe and the branch pipe, and a spoiler for mixing silane gas and hydrogen is movably provided inside the mixing chamber.

[0012] Preferably, the spoiler comprises a mounting frame movably mounted inside the mixing chamber, the mounting frame comprises an expansion portion located at the top and a guide portion located at the bottom with an isosceles trapezoidal cross section, and a first flow channel for hydrogen gas to flow out is formed at the bottom of the guide portion.

[0013] Preferably, the inclined surface of the guide portion is provided with symmetrically inclined spoilers and air ports corresponding one-to-one to the spoilers and communicating with the first flow channel.

[0014] Preferably, an absorption disk for absorbing gaseous silicon is disposed inside the reactor, and the spoiler moves relative to the mixing chamber to rotate the absorption disk.

[0015] Preferably, the expansion portion comprises a movable belt fixedly mounted on the mounting frame and used for guiding airflow, and a support plate used for supporting the movable belt, and the support plate moves relative to the mounting frame to make the expansion direction of the expansion portion adjustable.

[0016] Preferably, a movable rod for driving the absorption disk to rotate is provided on the reaction kettle, and a traction rope is provided between the movable rod and the mounting frame.

[0017] Preferably, a locking piece for fixing the support plate is movably provided on the mounting frame, and a wedge block for pushing the locking piece is symmetrically provided inside the mixing chamber.

[0018] Preferably, the width of the reaction channel decreases from the middle to both ends, and the starting end connected to the first processor is inclined.

[0019] A method for producing nano-silicon powder by silane CVD method, which is based on the gas supply system for producing nano-silicon powder by silane CVD method described in the above scheme, further comprising the following steps:

[0020] S1, introducing silane gas and hydrogen gas into a mixing chamber for mixing;

[0021] S2, the mixed gas is preheated inside the first processor and then enters the heater;

[0022] S3, the heater heats the silane to 400°C, and the silane is cracked to produce gaseous silicon and hydrogen;

[0023] S4. The gas flows through the absorption disk, which absorbs the gaseous silicon, and the remaining gas flows back to the mixing chamber for reuse.

[0024] In the above technical scheme, the present invention provides a gas supply system and gas supply method for producing nano-silicon powder by a silane CVD method, which has the following beneficial effects: when performing production work, the silane gas is first input into the branch pipe of the first processor through the air inlet pipe, the airflow enters the main pipe along the branch pipe and contacts the tangent guide cone ring, the airflow moves along the guide cone ring and forms a spiral airflow extending to the first end of the main pipe, and the gas flow speed is very fast. Part of the airflow rubs against the inner wall of the main pipe and the temperature rises. The preheated airflow enters the heater and moves along the wavy reaction channel in the heater. The heating plate on the inner wall of the reaction channel further heats the preheated silane, shortening the heating time of the silane to avoid excessive silane temperature. When heated to 400°C, the silane will thermally decompose to produce gaseous silicon and hydrogen, and then the gaseous silicon in the mixed gas is captured to produce nano-silicon. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0026] Figure 1 A schematic diagram of the overall structure provided for an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of the internal structure provided by an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of the structure of an absorption disk provided in an embodiment of the present invention;

[0029] Figure 4A schematic diagram of the internal structure of a first processor provided by an embodiment of the present invention;

[0030] Figure 5 A schematic diagram of the internal structure of a second processor provided by an embodiment of the present invention;

[0031] Figure 6 A schematic diagram of the internal structure of a heater provided by an embodiment of the present invention;

[0032] Figure 7 A schematic diagram of the structure of a reaction channel provided in an embodiment of the present invention;

[0033] Figure 8 A schematic diagram of the structure of a spoiler provided in an embodiment of the present invention;

[0034] Fig. 9 for Figure 8 Enlarged view of point A in the middle;

[0035] Fig.10 A schematic diagram of the internal structure of a mixing chamber provided in an embodiment of the present invention;

[0036] Fig.11 for Fig.10 Enlarged view of point B in the middle;

[0037] Fig.12 A schematic diagram of the internal structure of a mounting frame provided in an embodiment of the present invention.

[0038] Description of reference numerals:

[0039] 1. Reactor; 11. Mixing chamber; 111. Spoiler; 112. Mounting frame; 113. Support plate; 114. Movable belt; 115. Locking plate; 116. Wedge; 117. Spoiler; 118. First flow channel; 119. Air inlet; 121. Main pipe; 122. Branch pipe; 123. Fixing plate; 124. Guide cone ring; 125. Pipe head; 126. Air outlet; 127. Spiral flow channel; 128. First processor; 129. Second processor; 13. Heater; 131. Reactor; 132. Heating plate; 133. Starting end; 134. Terminal; 135. Tenon rod; 136. Second flow channel; 14. Absorption plate; 141. Movable rod; 142. Ratchet; 143. Towing rope; 151. Air inlet pipe; 152. Air outlet pipe. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0041] Embodiment 1

[0042] like Figure 1-12As shown, a gas supply system for producing nano-silicon powder by silane CVD method includes a reactor 1, and the reactor 1 is provided with:

[0043] Intake pipe 151:

[0044] A heater 13, wherein a wave-shaped reaction channel 131 is disposed inside the heater 13, and a heating plate 132 is disposed on the inner wall of the reaction channel 131;

[0045] The first processor 128 is located between the air intake pipe 151 and the heater 13. The first processor 128 includes a main pipe 121 and a branch pipe 122. A guide cone ring 124 is provided in the middle of the main pipe 121. The branch pipe 122 is perpendicular to the main pipe 121 and its axis is tangent to the guide cone ring 124.

[0046] The high-speed airflow enters the main pipe 121 along the branch pipe 122 , moves along the guide cone ring 124 and forms a spiral airflow extending toward the first end of the main pipe 121 , and heats up due to friction with the inner wall of the main pipe 121 before entering the heater 13 for further heating.

[0047] Specifically, the branch pipe 122 is provided with a fixing plate 123 with an air hole in the middle, and the inner diameter of the main pipe 121 increases from the guide cone ring 124 to the second end (in Figure 4 According to the invention, the left end of the main pipe 121 is the second end, and the right end is the first end), the second end of the main pipe 121 is provided with an outlet duct 126 connected with the air inlet pipe 151, the first end of the main pipe 121 is provided with a pipe head 125 connected with the heater 13, the middle part of the pipe head 125 is provided with a cone extending to the inside of the main pipe 121, and the inside of the pipe head 125 is provided with a spiral flow channel 127 distributed around the circumference of the cone.

[0048] Furthermore, when the production work is carried out, the high-pressure silane gas is first input into the branch pipe 122 of the first processor 128 through the air inlet pipe 151, and when the high-pressure gas passes through the air hole on the fixing plate 123 in the branch pipe 122, the gas flow speed is greatly accelerated due to the narrowing of the flow channel, and the high-speed airflow enters the main pipe 121 along the branch pipe 122 and contacts the guide cone ring 124 along the tangent direction of the guide cone ring 124. The airflow moves along the guide cone ring 124 and forms a spiral airflow extending to the first end of the main pipe 121. The gas flow speed is very fast, and the spiral airflow rubs against the inner wall of the main pipe 121 to increase the temperature. This part of the gas enters the heating after preheating. In the heater 13, another part of the gas with a lower temperature at the center of the main pipe 121 forms a reverse spiral airflow, which moves toward the second end of the main pipe 121 through the notch in the middle of the guide cone ring 124 and returns to the inlet pipe 151 along the outlet 126 for reuse. The airflow inside the heater 13 moves along the wavy reaction channel 131. The heating plate 132 on the inner wall of the reaction channel 131 further heats the preheated silane, shortening the heating time of the silane to avoid excessive temperature of the silane. When heated to 400°C, the silane will be thermally decomposed to produce gaseous silicon and hydrogen, and then the gaseous silicon in the mixed gas is captured to produce nano-silicon.

[0049] In the above technical scheme, when the production work is carried out, the silane gas is first input into the branch pipe 122 of the first processor 128 through the air inlet pipe 151, and the airflow enters the main pipe 121 along the branch pipe 122 and contacts the tangent guide cone ring 124. The airflow moves along the guide cone ring 124 and forms a spiral airflow extending to the first end of the main pipe 121, and the gas flow speed is very fast. Part of the airflow rubs against the inner wall of the main pipe 121 and the temperature rises. The preheated airflow enters the heater 13 and moves along the wavy reaction channel 131 in the heater 13. The heating plate 132 on the inner wall of the reaction channel 131 further heats the preheated silane, shortening the heating time of the silane to avoid the silane temperature being too high. When the silane is heated to 400°C, it will thermally decompose to produce gaseous silicon and hydrogen, and then capture the gaseous silicon in the mixed gas to produce nano-silicon.

[0050] As a further embodiment of the present invention, a mixing chamber 11 is provided between the air inlet pipe 151 and the branch pipe 122 , and a turbulent 111 for mixing silane gas and hydrogen is movably provided inside the mixing chamber 11 .

[0051] Specifically, when working, silane gas and start-up hydrogen are sent to the mixing chamber 11. The spoiler 111 in the mixing chamber 11 disturbs the airflow, causing the airflow to collide and intersect to allow hydrogen and silane gas to mix. Hydrogen can reduce the activity of silane and improve the safety of silane.

[0052] As another embodiment further provided by the present invention, the spoiler 111 includes a mounting frame 112 movably mounted inside the mixing chamber 11, the mounting frame 112 includes an expansion portion located at the top and a guide portion located at the bottom with an isosceles trapezoidal cross-section, and a first flow channel 118 for hydrogen gas to flow out is provided at the bottom of the guide portion.

[0053] Specifically, during operation, the silane gas flows vertically downward along the air inlet pipe 151. When passing through the spoiler 111, the airflow moves along the outer surface of the expansion portion of the spoiler 111, the gas flow rate accelerates and the airflow gradually approaches the two inclined surfaces of the guide portion below the expansion portion. The two airflows moving along the two inclined surfaces of the guide portion meet below the guide portion, and the high-speed flowing gas has a lower gas pressure, which will attract the slow-flowing hydrogen in the first flow channel 118 to move, thereby causing the hydrogen to mix with the silane gas.

[0054] As another embodiment further provided by the present invention, the inclined surface of the guide portion is provided with symmetrically inclined spoilers 117 and air ports 119 corresponding one-to-one to the spoilers 117 and connected to the first flow channel 118 .

[0055] Specifically, when the airflow moves along the inclined surface of the guide portion, the airflow will hit the spoiler 117 and move along the inclined spoiler 117. This part of the gas flows at a high speed and forms a vortex under the spoiler 117, and the center of the vortex faces the air port 119. At this time, the gas flowing in the first flow channel 118 will be attracted by the airflow vortex and pass through the air port 119 to mix with the silane.

[0056] As another embodiment further provided by the present invention, an absorption disk 14 for absorbing gaseous silicon is disposed inside the reactor 1, and the spoiler 111 moves relative to the mixing chamber 11 to rotate the absorption disk 14.

[0057] Specifically, the silane gas is thermally decomposed in the heater 13 to generate gaseous silicon and hydrogen. The mixed gas then flows through the absorption disk 14. The absorption disk 14 captures the gaseous silicon in the mixed gas and converts the gaseous silicon into nano-silicon powder. The hydrogen continues to move through the absorption disk 14 and enters the intake pipe 151 to mix with the silane gas.

[0058] As another embodiment further provided by the present invention, the expansion part includes a movable belt 114 fixedly mounted on a mounting frame 112 and used for guiding the airflow, and a support plate 113 for supporting the movable belt 114, the support plate 113 moves relative to the mounting frame 112 to make the expansion direction of the expansion part adjustable, and a movable rod 141 for driving the absorption disk 14 to rotate is provided on the reactor 1, and a traction rope 143 is provided between the movable rod 141 and the mounting frame 112.

[0059] Specifically, a ratchet 142 is disposed on the absorption disc 14 , a plurality of ratchet pawls adapted to the ratchet 142 are disposed on the movable rod 141 , and a spring is disposed between the movable rod 141 and the reaction kettle 1 .

[0060] Furthermore, during operation, the support plate 113 supports the movable belt 114 so that the expansion portion formed by the movable belt 114 protrudes toward one side of the mounting frame 112. When the gas flows at high speed, part of the gas flows along the protruding portion of the expansion portion, and the flow distance is longer, while the other side is relatively gentle, so that a pressure difference is formed on both sides of the expansion portion to push the expansion portion to move with the mounting frame 112 in the mixing chamber 11, and the mounting frame 112 drives the movable rod 141 to move inside the reactor 1 through the traction rope 143, and the movable rod 141 drives the ratchet 142 to rotate intermittently through the pawl, so that the working position of the absorption disk 14 is constantly changed, thereby ensuring the efficiency of the absorption disk 14 in capturing gaseous silicon. When the relative position of the support plate 113 and the mounting frame 112 changes, the expansion direction of the expansion portion can be adjusted, thereby changing the moving direction of the spoiler 111.

[0061] As another embodiment further provided by the present invention, a locking piece 115 for fixing the supporting plate 113 is movably provided on the mounting frame 112 , and a wedge block 116 for pushing the locking piece 115 is symmetrically provided inside the mixing chamber 11 .

[0062] Specifically, a spring is arranged between the locking piece 115 and the mounting frame 112, a locking groove adapted for the locking piece 115 is symmetrically provided on the support plate 113, a spring is arranged between the support plate 113 and the mixing chamber 11, a tenon rod 135 extending into the inner wall of the mixing chamber 11 is provided on the mounting frame 112, a groove connected to the first flow channel 118 is provided on the tenon rod 135, a second flow channel 136 for the reflux gas to flow into and facing the groove on the tenon rod 135 is provided on the mixing chamber 11, no matter where the spoiler 111 is, the gas in the second flow channel 136 can always enter the first flow channel 118 through the groove on the tenon block.

[0063] Furthermore, during the movement of the mounting frame 112, the locking piece 115 on the mounting frame 112 gradually approaches the inclined surface of one of the wedge blocks 116, and the spring between the support plate 113 and the mixing chamber 11 accumulates elastic potential energy, and the wedge block 116 pushes the locking piece 115 to move downward, so that the locking piece 115 is separated from the locking groove on the support plate 113. At this time, the spring releases the elastic potential energy, driving the support plate 113 to move relative to the mounting frame 112, so that the expansion portion formed by the movable belt 114 protrudes to the other side, the locking piece 115 is opposite to the other locking groove, and the pressure difference on both sides of the expansion portion pushes the mounting frame 112 to move in the opposite direction, the locking piece 115 is separated from the tenon, and the locking piece 115 is reinserted into the support plate 113 under the action of the spring to fix the support plate 113 on the mounting frame 112.

[0064] As another embodiment further provided by the present invention, the width of the reaction channel 131 decreases from the middle to both ends, and the starting end 133 connected to the first processor 128 is inclined.

[0065] Specifically, the inclined design of the starting end 133 of the reaction channel 131 can allow as much gas as possible to collide with the heating plate 132 on the inner wall of the reaction channel 131 when the gas enters the reaction channel 131, so that the heating plate 132 can heat the gas. The reactor 1 is provided with a second processor 129 having a structure similar to that of the first processor 128, and the taper of the guide cone ring 124 in the second processor 129 is smaller than that of the guide cone ring 124 in the first processor 128, so that the through hole in the middle of the guide cone ring 124 in the second processor 129 is larger, and the branch pipe 122 of the second processor 129 is connected to the terminal 134 of the reaction channel 131, and the second end of the main pipe 121 of the second processor 129 is directly opposite to the gas outlet 119 (with Figure 5 According to the invention, the upper end of the main pipe 121 is the first end, and the lower end is the second end), the air outlet 119 , the first end of the main pipe 121 of the second processor 129 , and the air outlet 126 are all connected to the second flow channel 136 .

[0066] Furthermore, when carrying out production work, the high-pressure silane gas is first introduced into the mixing chamber 11 through the air inlet pipe 151, and the silane gas flows vertically downward along the air inlet pipe 151. When passing through the spoiler 111, the airflow moves along the outer surface of the expansion part of the spoiler 111, the gas flow rate is accelerated, and the airflow gradually approaches the two inclined surfaces of the guide part below the expansion part. When the airflow moves along the inclined surface of the guide part, the airflow will hit the spoiler 117 and move along the inclined spoiler 117. This part of the gas flows at a high speed and forms a vortex below the spoiler 117, and the vortex center of the vortex is opposite to the air port 119. At this time, the gas flowing in the first flow channel 118 will be attracted by the airflow vortex and pass through the air port 119 to mix with silane. The two airflows continue to move along the two inclined surfaces of the guide part and meet below the guide part. The high-speed flowing gas has a lower air pressure, which will attract the slow-flowing hydrogen in the first flow channel 118 to move, thereby mixing the hydrogen with the silane gas.

[0067] Then the mixed gas enters the branch pipe 122 of the first processor 128, and when the high-pressure gas passes through the air holes on the fixed plate 123 in the branch pipe 122, the gas flow speed is greatly accelerated due to the narrowing of the flow channel. The high-speed airflow enters the main pipe 121 along the branch pipe 122 and contacts the guide cone ring 124 along the tangent direction of the guide cone ring 124. The airflow moves along the guide cone ring 124 and forms a spiral airflow extending to the first end of the main pipe 121. The gas flow speed is very fast, and the spiral airflow rubs against the inner wall of the main pipe 121 to increase the temperature. This part of the gas enters the heater 13 after preheating, and the other part of the gas with a lower temperature in the center of the main pipe 121 forms a reverse spiral airflow. This part of the airflow passes through the notch in the middle of the guide cone ring 124 and moves to the second end of the main pipe 121, and returns to the air inlet pipe 151 along the outlet 126 for reuse. The airflow inside the heater 13 moves along the wavy reaction channel 131 The heating plate 132 on the inner wall of the reaction channel 131 further heats the preheated silane, shortening the heating time of the silane to avoid the silane temperature being too high. When heated to 400°C, the silane will thermally decompose to produce gaseous silicon and hydrogen, and then the mixed gas enters the second processor 129. The higher temperature gas in the second processor 129 spirals upward into the second flow channel 136, and the lower temperature gas spirals downward and gradually passes through the guide cone ring 124 in the second processor 129 and contacts the absorption disk 14. The absorption disk 14 captures the gaseous silicon therein. The lower temperature gas can also protect the absorption disk 14. The remaining gas returns to the second flow channel 136 through the outlet pipe 152, and the gaseous silicon will collide with each other during the upward spiral movement, and gradually move to the middle part of the main pipe 121, and then move along the downward spiral airflow. The guide cone with a larger through hole in the second processor 129 can also allow more gas to flow downward.

[0068] Furthermore, in the above-mentioned embodiment, the absorption disk 14 captures the gaseous silicon by a commonly used low-temperature adsorption method of silicon.

[0069] Embodiment 2

[0070] A method for producing nano-silicon powder by silane CVD method, which is based on the gas supply system for producing nano-silicon powder by silane CVD method in the above scheme, further comprising the following steps:

[0071] S1, introducing silane gas and hydrogen gas into the mixing chamber 11 for mixing;

[0072] S2, the mixed gas is preheated inside the first processor 128 and then enters the heater 13;

[0073] S3, the heater 13 heats the silane to 400°C, and the silane is cracked to produce gaseous silicon and hydrogen;

[0074] S4. The gas flows through the absorption disk 14, which absorbs the gaseous silicon, and the remaining gas flows back to the mixing chamber 11 for reuse.

[0075] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A gas supply system for producing nano-silicon powder by silane CVD method, characterized in that: The invention comprises a reaction kettle (1), wherein the reaction kettle (1) is provided with: Inlet pipe (151): A heater (13), wherein a wavy reaction channel (131) is provided inside the heater (13), and a heating plate is provided on the inner wall of the reaction channel (131); A first processor (128) is located between the air intake pipe (151) and the heater (13), the first processor (128) comprising a main pipe (121) and a branch pipe (122), a guide cone ring (124) is provided in the middle of the main pipe (121), the branch pipe (122) is perpendicular to the main pipe (121) and its axis is tangent to the guide cone ring (124), wherein: The high-speed airflow enters the main pipe (121) along the branch pipe (122), moves along the guide cone ring (124) and forms a spiral airflow extending toward the first end of the main pipe (121), and the airflow heats up due to friction with the inner wall of the main pipe (121) and enters the heater (13) for further heating.

2. The gas supply system for producing nano-silicon powder by silane CVD method according to claim 1, characterized in that: A mixing chamber (11) is provided between the air inlet pipe (151) and the branch pipe (122), and a turbulent (111) for mixing silane gas and hydrogen is movably provided inside the mixing chamber (11).

3. The gas supply system for producing nano-silicon powder by silane CVD method according to claim 2, characterized in that: The spoiler (111) comprises a mounting frame (112) movably mounted inside the mixing chamber (11), the mounting frame (112) comprising an expansion portion located at the top and a guide portion located at the bottom with an isosceles trapezoidal cross section, the bottom of the guide portion being provided with a first flow channel (118) for hydrogen to flow out.

4. The gas supply system for producing nano-silicon powder by silane CVD method according to claim 3, characterized in that: The inclined surface of the guide portion is provided with symmetrically inclined spoilers (117) and air ports (119) corresponding one-to-one to the spoilers (117) and communicating with the first flow channel (118).

5. The gas supply system for producing nano-silicon powder by silane CVD method according to claim 3, characterized in that: An absorption disk (14) for absorbing gaseous silicon is arranged inside the reaction kettle (1), and the spoiler (111) moves relative to the mixing chamber (11) to rotate the absorption disk (14).

6. The gas supply system for producing nano-silicon powder by silane CVD method according to claim 5, characterized in that: The expansion portion comprises a movable belt (114) fixedly mounted on the mounting frame (112) and used for guiding airflow, and a support plate (113) used for supporting the movable belt (114); the support plate (113) moves relative to the mounting frame (112) so that the expansion direction of the expansion portion is adjustable.

7. The gas supply system for producing nano-silicon powder by silane CVD method according to claim 6, characterized in that: The reaction kettle (1) is provided with a movable rod (141) for driving the absorption disk (14) to rotate, and a traction rope (143) is provided between the movable rod (141) and the mounting frame (112).

8. The gas supply system for producing nano-silicon powder by silane CVD method according to claim 6, characterized in that: A locking piece (115) for fixing the support plate (113) is movably arranged on the mounting frame (112), and a wedge block (116) for pushing the locking piece (115) is symmetrically arranged inside the mixing chamber (11).

9. The gas supply system for producing nano-silicon powder by silane CVD method according to claim 1, characterized in that: The width of the reaction channel (131) decreases from the middle to both ends, and the starting end (133) connected to the first processor (128) is inclined.

10. A gas supply method for producing nano silicon powder by silane CVD method, characterized in that: The gas supply system for producing nano-silicon powder by the silane CVD method according to any one of claims 1 to 9 further comprises the following steps: S1, introducing silane gas and hydrogen gas into a mixing chamber (11) for mixing; S2, the mixed gas is preheated inside the first processor (128) and then enters the heater (13); S3, the heater (13) heats the silane to 400°C, and the silane is cracked to produce gaseous silicon and hydrogen; S4. The gas flows through the absorption disk (14), the absorption disk (14) absorbs the gaseous silicon, and the remaining gas flows back to the mixing chamber (11) for reuse.

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