CN108048903A - A kind of drainage system for changing carrier gas flow direction - Google Patents

Abstract

The invention belongs to polycrystalline cast ingot apparatus fields, specifically disclose a kind of drainage system for changing carrier gas flow direction, including the intake section, distributary division and conduction part being fixedly connected sequentially, the built-in air admission hole flowed into for carrier gas of intake section, splitter cavity built in distributary division, the drainage air flue that conduction part is flowed to by least one for changing carrier gas are formed, and the air admission hole is connected with splitter cavity, the air inlet of drainage air flue is connected with splitter cavity, and equidirectional angular distribution is circumferentially pressed in gas outlet.Drainage system of the present invention has the visual field led in ingot furnace, and drainage system makes carrier gas dispersedly blow the different zones for penetrating liquid silicon face, increases the contact area of carrier gas and liquid silicon face, and the impurity that local supercooling and carrier gas caused by reducing carrier gas promote is formed；Rotational flow field is generated in carrier gas driving liquid-state silicon, under the collective effect of free convection flow field and rotational flow field, promotes impurity volatilization, the impurity local enrichment in liquid-state silicon is reduced, the radial direction resistivity of crystal is made to be more evenly distributed.

Description

Drainage device for changing flow direction of carrier gas

The present application is a divisional application of a patent application having application number 201610082942.8, application date 2016-02-03, entitled diversion device for changing the flow direction of a carrier gas.

Technical Field

The invention relates to a drainage device, in particular to a drainage device for changing the flow direction of carrier gas for a polycrystalline ingot furnace, and belongs to the field of crystal growth equipment.

Background

The polycrystalline ingot furnace 10 mainly comprises an infrared detector 16, a furnace body 11, a flow guiding device 12, a heat insulation cage 13, a heater 14 and a graphite platform 15, and is shown in figure 1. The drainage device 12 comprises a graphite pipe 123, a coupling nut 121 and a drainage pipe 122. The upper end of the flow guide tube 122 is provided with an external thread matched with the internal thread of the adapter nut 121, the upper end of the flow guide tube 122 penetrates through a through hole in the middle of the top heat-insulation plate of the heat-insulation cage and is fixed with the adapter nut 121 above the top heat-insulation plate, and the lower end of the flow guide tube 122 is over against the silicon material in the crucible. Graphite tube 123 fits between mating nut 121 and the viewing port of the furnace roof. An infrared detector 16 is arranged right above the drainage device 12, and a probe of the infrared detector 16 is right opposite to a silicon material 17 in the ingot furnace. The flow guide device 12 is mainly used for conveying carrier gas into the furnace, observing the condition in the furnace, inserting a crystal measuring bar to measure the growth speed of the crystal, and detecting the state of the silicon material in the furnace by an infrared detector. The tapping device 12 is the only way to view the conditions inside the furnace, in particular the silicon material conditions. The infrared detector 16 is used for detecting whether the state of the silicon material is solid or liquid, in the automatic crystal growth process, the polycrystalline ingot furnace performs alarm processing such as material melting completion, middle crystal growth completion and the like according to the change of signals of the infrared detector 16 so as to alarm an operator to confirm the state and the crystal growth condition of the silicon material through the drainage device 12 in time, perform operation processing and enter the next process.

The polycrystalline ingot furnace mostly adopts a heating mode of heating four side walls and five top surfaces, as shown in figure 1. The temperature of the four sides of the liquid silicon in the crucible is higher than that of the middle part of the crucible, so that a natural convection flow field with the liquid silicon on the four sides floating up and the liquid silicon in the middle part sinking down is formed. If the melting degree of some impurities (such as carbon and nitrogen) melted in the liquid silicon with higher temperature on the four sides reaches or approaches saturation, when the liquid silicon flows to the middle part, the melting degree of the impurities is over saturated due to the temperature reduction, and the impurities such as carbon and nitrogen are nucleated and separated out; the impurity nuclei drop in temperature with the falling of the liquid flow and grow gradually to form impurity inclusions. As shown in FIG. 1, the carrier gas is intensively and vertically blown to the central region of the liquid silicon material 17 through the outlet of the flow guiding device 12, the amount of the carrier gas contacting per unit area of the region is large, the heat quantity carried by the carrier gas from the liquid silicon in the region is large, the temperature of the liquid silicon in the region is further reduced, the supercooling degree is enhanced, and therefore the supersaturation nucleation of impurities in the liquid silicon, such as carbon, nitrogen and the like, is promoted, and the growth of the impurity nuclei is promoted to form macroscopic impurities, such as silicon carbide impurities and silicon nitride impurities. Silicon carbide impurities are electrically active and can affect the conversion efficiency of solar cells. Chinese patent applications No. 201310564191.X and 201310564069.2 both disclose a flow directing device for changing the flow direction of a carrier gas in order to rotate the liquid silicon in the crucible to enhance the volatilization of impurities. The flow directing devices disclosed in both patent applications deflect the carrier gas away from the center of the liquid silicon and blow obliquely at the surface of the liquid silicon, but have several problems: the carrier gas is still intensively blown to a certain area of the surface of the liquid silicon, so that the temperature of the area is reduced, the liquid silicon is supercooled, and the nucleation growth of impurities in the liquid silicon is promoted; the carrier gas does not form carrier gas stress distributed circumferentially on the surface of the liquid silicon, and a rotary flow field is difficult to form in the liquid silicon; the view field in the drainage device leading to the interior of the ingot furnace is completely shielded, and the state in the ingot furnace cannot be observed through the observation window at the top of the furnace through the drainage device, so that the furnace operation is inconvenient; the crystal measuring bar cannot penetrate through the drainage device and is inserted into the ingot furnace, and the growth speed of the crystal is inconvenient to measure; and the infrared detector can not detect the state of the silicon material in the furnace, and the automatic crystal growth process can not be normally carried out. Therefore, it is urgently needed to develop a drainage device for a polycrystalline ingot furnace for changing the flow direction of carrier gas, so that the carrier gas is dispersedly blown to different areas of the surface of the liquid silicon, the contact area between the carrier gas flow and the surface of the liquid silicon is increased, the carrier gas stress distributed circumferentially is formed on the surface of the liquid silicon, and the liquid silicon is driven to flow circumferentially to form a rotating flow field; meanwhile, the drainage device is provided with a view field leading to the ingot furnace.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a drainage device for a polycrystalline ingot furnace, which is used for changing the flow direction of a carrier gas. The problems of the prior drainage device in application are overcome: carrier gas is intensively blown to a certain area of the surface of the liquid silicon, and the carrier gas takes away a large amount of heat from the area to cause local supercooling of the liquid silicon in the area and promote nucleation growth of impurities in the liquid silicon; the carrier gas does not form carrier gas stress distributed circumferentially on the surface of the liquid silicon, and a rotary flow field is difficult to form in the liquid silicon; the view field in the drainage device leading to the interior of the ingot furnace is completely shielded, and the state in the ingot furnace cannot be observed through the observation window and the drainage device, so that the furnace operation is inconvenient; the crystal measuring bar cannot penetrate through the drainage device and is inserted into the ingot furnace, so that the growth speed of the crystal is inconvenient to measure; the infrared detector cannot detect the state of the silicon material in the furnace, and the automatic crystal growth process cannot be normally carried out.

The technical scheme of the invention provides a drainage device for changing the flow direction of carrier gas for a polycrystalline ingot furnace, which is characterized in that: including fixed connection's air inlet, reposition of redundant personnel portion and drainage portion in proper order, the built-in inlet port that is used for the carrier gas to flow in of air inlet, the built-in reposition of redundant personnel chamber of reposition of redundant personnel portion, drainage portion comprises at least one drainage air flue that is used for changing the carrier gas flow direction, the inlet port with reposition of redundant personnel chamber intercommunication, the air inlet and the reposition of redundant personnel chamber intercommunication of drainage air flue, the gas outlet is according to the angular distribution of equidirectional along circumference.

In the practice of the present invention, the following further preferred embodiments are also provided.

Preferably, the flow dividing part and the drainage part are integrally formed and are cylindrical bodies provided with through holes along the central line direction of the flow dividing part, and annular flow dividing cavities extending along the circumferential direction are arranged in the side walls of the flow dividing part; the lateral wall of drainage portion sets up the drainage air flue that extends downwards from the lower extreme face of reposition of redundant personnel chamber in, and the gas outlet of drainage air flue is located the lower extreme of drainage portion. .

Preferably, the flow dividing part and the flow guiding part are cylindrical bodies provided with through holes along the central line direction of the flow dividing part, the flow dividing part comprises a first flow dividing part and a second flow dividing part which are fixedly connected in the axial direction, and the second flow dividing part and the flow guiding part are integrally formed; a first shunting cavity with an annular lower end surface opening and extending along the circumferential direction is arranged in the side wall of the lower end part of the first shunting part, and the air inlet is communicated with the first shunting cavity; a second flow dividing cavity which extends along the circumferential direction and is provided with an opening at the upper end face is arranged in the side wall of the upper end part of the second flow dividing part, the second flow dividing cavity corresponds to the first flow dividing cavity, and the first flow dividing cavity and the second flow dividing cavity form the flow dividing cavity; set up the drainage air flue that extends downwards from second reposition of redundant personnel chamber lower extreme face in the lateral wall of drainage portion, the gas outlet of drainage air flue is located the lower extreme of drainage portion.

Preferably, the air inlet hole is communicated with the flow dividing cavity through a communicating air passage, one end of the communicating air passage is communicated with the air inlet hole in a tangent mode, and the other end of the communicating air passage is communicated with the side face of the flow dividing cavity in a tangent mode.

Preferably, the air inlet part is an air inlet pipe with a built-in air inlet hole, and the drainage part comprises a drainage air pipe with a built-in drainage air passage; the flow dividing part is an annular closed cavity mainly formed by an inner side wall, an outer side wall, an upper end wall and a lower end wall, and the inner side wall, the outer side wall, the upper end wall and the lower end wall form the flow dividing cavity; one end of the air inlet pipe is communicated and fixed with the flow dividing cavity; the drainage trachea sets up in the below of reposition of redundant personnel portion, and the air inlet and the reposition of redundant personnel chamber intercommunication of drainage trachea upper end to fixed with drainage portion, the gas outlet of drainage trachea lower extreme is according to the angular distribution of equidirectional along circumference.

Preferably, the air inlet pipe is communicated with the flow dividing cavity of the flow dividing part through a communicating pipe, one end of the communicating pipe is communicated and fixed with the air inlet pipe in a tangent mode, and the other end of the communicating pipe is communicated and fixed with the side wall of the flow dividing cavity in a tangent mode.

Preferably, the air inlet part is arranged in the flow dividing part, and the central line of the air inlet hole is parallel to the central line of the flow dividing part; or,

the air inlet part is arranged outside the flow dividing part, and the central line of the air inlet hole is parallel or vertical to the central line of the flow dividing part.

Preferably, the drainage air passage extends along a cylindrical spiral line, the pitch of the spiral line at the air outlet section of the drainage air passage is gradually reduced, and the air outlet of the drainage air passage is positioned right below the lower end face of the flow dividing part; or,

the drainage air flue extends along cylindrical spiral line, the pitch of the spiral line of drainage air flue gas outlet section reduces gradually, the radius increases gradually, and the gas outlet of drainage air flue is located the lower extreme of the lateral wall extending surface of reposition of redundant personnel portion or is located the outside of reposition of redundant personnel portion lateral wall extending surface.

Preferably, the number of drainage airways is 2, 3 or 4.

Preferably, the material of the air inlet part, the flow dividing part and the flow guiding part is graphite, molybdenum, tungsten or titanium.

The air inlet part of the drainage device can be arranged inside the flow dividing part or outside the flow dividing part. When the air inlet part is arranged in the shunting part, the through hole through which the air conveying pipe penetrates can be prevented from being formed in the double-layer water-cooled steel furnace body of the polycrystalline ingot furnace and the heat insulation plate of the heat insulation cage, and the air conveying pipe is convenient to arrange and communicate. The air inlet part shields a view field leading to the inside of the ingot furnace in the drainage device, but the shielded area is less than one fourth of the area of the view field, and the drainage device is provided with the view field leading to the inside of the ingot furnace. The state of the silicon material in the ingot furnace can be observed through an observation window on the top of the furnace through the drainage device, and a crystal measuring bar can be inserted to measure the growth speed of the crystal; the infrared detector can detect the state of the silicon material in the furnace through an observation window at the top of the furnace, and the automatic crystal growth process is smoothly carried out. The drainage device divides the carrier gas into a plurality of carrier gas flows which are respectively blown to different areas of the surface of the liquid silicon in an inclined mode, so that the contact area of the carrier gas and the surface of the liquid silicon is effectively increased, the amount of the carrier gas in contact with a unit area is small, the heat taken away by the carrier gas from the unit area is small, the temperature of the liquid silicon in the area is reduced by the carrier gas, the supercooling degree is weakened, and the impurity supersaturation nucleation caused by the carrier gas in the liquid silicon in the area and the formation of impurity inclusions caused by the growth of the promoted impurity nuclei are reduced or even eliminated. The emergent carrier gas flow flowing out of the drainage device dispersedly and obliquely blows different areas of the surface of the liquid silicon, the blown areas are distributed circumferentially around the center of the liquid silicon, the emergent carrier gas flow generates carrier gas stress on the liquid silicon, the carrier gas stress is distributed circumferentially around the center of the liquid silicon, and the carrier gas stress drives the surface layer liquid silicon to flow and form a rotary flow field which flows circumferentially. The rotating flow field is beneficial to conveying impurities in the liquid silicon to the surface and promoting the volatilization of the impurities; the rotating flow field is also beneficial to the transportation and uniform distribution of impurities in the liquid silicon, so that the radial resistivity distribution of the crystal is more uniform.

Advantageous effects

The drainage device is provided with a view field leading to the interior of the ingot furnace, and when the air inlet part is arranged outside the flow dividing part, the view field leading to the interior of the ingot furnace in the drainage device is not shielded; when the air inlet part is arranged in the flow dividing part, although the air inlet part shields the view field, the shielded area is less than one fourth of the area of the view field, and the flow guiding device still has the view field leading to the ingot furnace; therefore, the state in the ingot furnace can be smoothly observed through the drainage device, and the furnace operation is convenient; inserting a crystal measuring bar through a drainage device, and measuring the growth speed of the crystal; the infrared detector can detect the state of the silicon material in the ingot furnace through the drainage device, and the automatic crystal growth process can be smoothly carried out.

The local supercooling caused by the carrier gas in the liquid silicon is reduced, the carrier gas is divided into a plurality of carrier gas flows by a plurality of drainage gas passages of the drainage device, the plurality of carrier gas flows are scattered and obliquely blown to different areas of the surface of the liquid silicon, the contact area between the carrier gas and the surface of the liquid silicon is effectively increased, the amount of the carrier gas which is contacted on the unit area of the liquid silicon in the carrier gas blowing area is reduced, the heat taken away by the carrier gas flow on the unit area is reduced, and the local temperature reduction amplitude of the area caused by the carrier gas flow is reduced, so that the local supercooling caused by the carrier gas in the liquid silicon and the promoted growth of impurity nucleation are reduced or even avoided.

The crystal quality is improved, a plurality of drainage air passages of the drainage device are uniformly distributed around the central line of the drainage device, carrier gas is divided into a plurality of carrier gas flows through the drainage air passages, the carrier gas flows are obliquely blown to different areas of the surface of the liquid silicon respectively, the blown areas of the carrier gas flows are distributed around the center of the surface of the liquid silicon, the carrier gas flows generate carrier gas stress for driving laminar flow to the liquid silicon, and the carrier gas stress drives the liquid silicon to flow to form a rotary flow field flowing around the center of the liquid silicon. The rotating flow field is beneficial to conveying the floating impurities on the surface of the liquid silicon to the edge of the liquid silicon, so that the influence of the floating impurities on the yield of crystals is reduced, and the yield of the crystals is improved; the method is also beneficial to conveying impurities in the liquid silicon to the surface of the liquid silicon and accelerating the volatilization of the impurities in the liquid silicon; under the combined action of the natural convection flow field and the rotary flow field, the liquid silicon is beneficial to the transportation and the uniform distribution of impurities in the liquid silicon, the local enrichment of the impurities is avoided, the radial resistivity distribution of the crystal is more uniform, and the quality of the crystal is further improved.

Drawings

FIG. 1 is a schematic structural diagram of a polycrystalline ingot furnace in the prior art.

Fig. 2 is a schematic view of a state of use of the drainage device 100 according to embodiment 1.

Fig. 3 is a schematic cross-sectional view of the drainage device 100 of fig. 2.

Fig. 4 is a schematic cross-sectional view of the first flow dividing portion 21 in fig. 3.

FIG. 5 is a schematic sectional view taken along line A-A of FIG. 4.

FIG. 6 is a schematic sectional view taken along line B-B in FIG. 3.

Fig. 7 is a schematic bottom view of fig. 3.

Fig. 8 is a schematic view of the distribution of the drainage airway 6 after the flow divider 3 in fig. 3 is deployed along the OR section in fig. 6.

Fig. 9 is a schematic sectional view of another structure of the flow dividing portion 3.

Fig. 10 is a schematic sectional view taken along the direction C-C in fig. 9.

Fig. 11 is a schematic view showing the assembly relationship of the drainage device 100 according to embodiment 2 in a use state.

Fig. 12 is a schematic cross-sectional view of the drainage device 100 of fig. 11.

Fig. 13 is a schematic sectional view taken along the direction D-D in fig. 12.

Fig. 14 is a schematic bottom view of the drainage device 100 of fig. 12.

Fig. 15 is a schematic diagram showing the distribution of the diversion airway 6 after the diversion part 3 in fig. 12 is expanded along the OR section in fig. 13.

FIG. 16 is a cross-sectional view of an alternative configuration of the drainage device 100 of FIG. 11.

FIG. 17 is a schematic view of a cross-section taken along line E-E in FIG. 16.

Fig. 18 is a schematic view showing an assembly relationship of an applied state of the drainage device 100 according to embodiment 3.

Fig. 19 is a schematic cross-sectional view of the drainage device 100 of fig. 18.

FIG. 20 is a schematic sectional view taken along the direction F-F in FIG. 19.

FIG. 21 is a schematic view of a pilot airway design.

In the figure, 1-an air inlet part, 2-a flow dividing part, 3-a drainage part, 4-an air inlet hole, 5-a flow dividing cavity, 6-a drainage air passage, 7-a drainage air pipe, 8-a communication air passage, 9-a communication pipe, 10-a fastening part, 11-an internal thread, 12-a drainage device in the prior art, 31-a flange, 51-a first flow dividing cavity, 52-a second flow dividing cavity, 50-an air pipe, 60-a top insulation board, 100-a drainage device, 121-a matching nut, 122-a flow guiding pipe, 123-a graphite pipe, 211-an internal thread and 221-an external thread.

Detailed Description

In order to clarify the technical solution and technical object of the present invention, the present invention will be further described with reference to the accompanying drawings and the detailed description.

Embodiment mode 1

Referring to fig. 2 and 3, the flow guide device 100 for changing the flow direction of a carrier gas according to the present invention includes an air inlet portion 1, a flow dividing portion 2, and a flow guide portion 3. The air inlet part 1 and the flow dividing part 2 are fixed, and the flow dividing part 2 and the drainage part 3 are fixed. The flow dividing part 2 and the drainage part 3 are both cylindrical bodies provided with through holes along the central line direction thereof, and are preferably cylinders. As shown in fig. 3, the flow dividing portion 2 includes a first flow dividing portion 21 and a second flow dividing portion 22, and the second flow dividing portion 22 and the drain portion 3 are integrally formed to constitute a drain cylinder. The lower end part of the first flow dividing part 21 is provided with an internal thread 211, and the upper end part of the second flow dividing part 22 is provided with an external thread 221; the internal thread 211 and the external thread 221 are coupled as shown in fig. 3. The middle part of drainage portion 3 sets up and makes the flange 31 of circumference extension along its surface, as shown in fig. 3, flange 31 encircles 3 surface of drainage portions a week, forms on the surface of drainage portions 3 and is annular protruding structure, plays spacing, fixed action. In application, the upper end of the drainage cylinder penetrates through a through hole in the middle of the top insulation board 60 of the insulation cage, as shown in fig. 2, and is axially assembled with the first shunt part 21 arranged above the top insulation board 60, and the first shunt part 21 and the second shunt part 22 of the drainage cylinder are tightly connected through the internal and external threads 211 and 221. The first flow-dividing portion 21 and the flange 31 cooperate to secure the drainage tube to the top insulation panel 60. The material of the inlet section 1, the flow dividing section 2 and the flow guiding section 3 is graphite, preferably isostatic graphite, or may be molybdenum or titanium, which is a high-cost metal.

As shown in fig. 4, a counter bore with an inner diameter larger than that of the through hole is provided at the top of the first flow dividing part 21, the counter bore and the through hole share a center line, and the counter bore and the through hole cooperate to form an annular step 212 at the top of the first flow dividing part 21. The annular step 212 is used to assemble a prior art graphite tube 123 for transporting a carrier gas, as shown in fig. 2. A first flow dividing chamber 51 having an annular lower end surface opening and extending in the circumferential direction is provided in the side wall of the first flow dividing portion 21, the first flow dividing chamber 51 and the first flow dividing portion 21 are concentric, and as shown in fig. 4 and 5, the first flow dividing chamber 51 is located below the annular step 212. The inner wall of the lower end of the first branch portion 21 is provided with the above-mentioned internal thread 211, and the internal thread 211 is located below the first branch chamber 51. The internal thread 211 extends in the direction of the center line of the first diverging portion 21 and is concentric with the first diverging portion 21, as shown in fig. 4.

The intake portion 1 is provided inside the tubular first flow dividing portion 21, as shown in fig. 4 and 5, and is fixed to the inner wall of the first flow dividing portion 21. Further, the air inlet portion 1 and the first flow dividing portion 21 are integrally formed to avoid the problem that graphite material members are not easily fixedly connected. An air inlet hole 4 for the carrier gas to flow into is arranged in the air inlet part 1, the central line of the air inlet hole 4 is parallel to the central line of the first flow dividing part 21, and as shown in fig. 4 and 5, the air inlet of the air inlet hole 4 is arranged upwards. The air inlet hole 4 is communicated with the first branch flow cavity 51 through a communication air channel 8. The communicating air duct 8 is arranged in a clockwise direction (viewed from top to bottom), as shown in fig. 5, one end portion of the communicating air duct 8 is tangentially communicated with the air inlet hole 4, the other end portion is tangentially communicated with the side wall surface of the first diversion chamber 51, and the carrier gas flow in the communicating air duct 8 flows into the first diversion chamber 51 in the clockwise direction (viewed from top to bottom).

The air inlet portion 1 may also be disposed outside the first branch portion 21 (not shown in the figures), and the air inlet portion 1 and the first branch portion 21 are integrally formed to avoid the problem that the graphite material member is not easily fixed and connected. An air inlet hole 4 for carrier gas to flow in is arranged in the air inlet part 1, the central line of the air inlet hole 4 is parallel to the central line of the first flow dividing part 21, and the opening of the air inlet hole 4 is upwards arranged or downwards arranged according to requirements. The air inlet hole 4 is communicated with the first diversion cavity 51 through the communicating air channel 8, one end part of the communicating air channel 8 is tangentially communicated with the air inlet hole 4, the other end part of the communicating air channel 8 is tangentially communicated with the side surface of the first diversion cavity 51, and the carrier gas flow in the communicating air channel 8 flows into the first diversion cavity 51 in a clockwise direction (seen from top to bottom). In addition, the central line of the air inlet hole 4 and the central line of the first flow dividing part 21 can also be vertically arranged, the air inlet hole 4 is tangentially communicated with the first flow dividing cavity 51, and the opening of the air inlet hole 4 is arranged on the left side of the first flow dividing part 21 according to the requirement and can also be arranged on the right side thereof according to the requirement of assembly.

The external thread 221 is provided on the outer wall surface of the upper end of the second branch portion 22, and the external thread 221 is engaged with the internal thread 211. A second branch chamber 52 with an open upper end surface is arranged in the side wall of the second branch part 22, the second branch chamber 52 is an annular chamber surrounding the center line of the second branch part 22 for one circle, as shown in fig. 3, the external thread 221 is nested outside the outer side wall of the second branch part 22. The second branch chamber 52, the external thread 221 and the second branch portion 22 are concentric. The second branch chamber 52 corresponds to the first branch chamber 51, that is, the upper end opening of the second branch chamber 52 is opposite to the lower end opening of the first branch chamber 51. The second branch chamber 52 and the first branch chamber 51 constitute the branch chamber 5 of the branch portion 2. 4 drainage air passages 6 are arranged in the side wall of the drainage part 3 of the drainage tube, as shown in fig. 6-8, the 4 drainage air passages 6 are uniformly distributed around the central line of the drainage part 3, as shown in fig. 6, the number of the drainage air passages 6 can be 2, 3 or more than 5. The drainage air duct 6 extends downward from the lower end face of the second diversion cavity 52 along a cylindrical spiral line, i.e. the central line of the drainage air duct 6 extends downward along the spiral line direction and coincides with the spiral line. The spiral line has a non-uniform pitch, the pitch at the upper end of the spiral line is longer, the pitch at the lower end of the spiral line is shorter, and the pitch at the outlet of the drainage air passage is shortest; the helix is located the lateral wall of drainage portion 3, rotates along the clockwise (when looking down from the top), and is the same with the direction of carrier gas air current in the intercommunication air flue 7, helix and drainage portion 3 common centerline. The air inlet of the upper end of the drainage air duct 6 is communicated with the lower end surface of the second diversion cavity 52, and the air outlet of the lower end of the drainage air duct 6 is positioned at the lower end of the drainage part 3, as shown in fig. 3 and 9.

The drainage air passage 6 and the communication air passage 8 are arranged along the same spiral direction, the communication air passage 8, the air inlet hole 4 and the first diversion cavity 51 are respectively communicated in a tangent mode, and smooth transition is respectively carried out at the communication positions. The air flue distributed in such a way makes the flowing direction of the carrier gas in the flow dividing cavity the same as the flowing direction of the carrier gas in the drainage air flue 6, so that the resistance of the carrier gas flowing can be reduced, the carrier gas keeps higher kinetic energy and enters the first flow dividing cavity 51 and the second flow dividing cavity 52, the carrier gas rotates in the first flow dividing cavity and the second flow dividing cavity, and a longer flow path is provided, so that the carrier gas can uniformly flow into the drainage air flue 6. The flow resistance met by the carrier gas flowing through the air inlet 4, the communicating air passage 8, the first two-way flow cavities 51 and 52 and the drainage air passage 6 is small, the kinetic energy loss is small, the carrier gas still has high energy when flowing to the air outlet of the drainage air passage 6, so that the carrier gas has high emergent speed, the emergent carrier gas flow generates large carrier gas stress on liquid silicon, the liquid silicon rotation is facilitated, and a strong rotation flow field is generated in the liquid silicon.

Embodiment mode 2

As shown in fig. 11 and 12, the drainage device 100 of the present invention includes a fixing portion 10, an air inlet portion 1, a flow dividing portion 2, and a drainage portion 3. Air inlet portion 1 and reposition of redundant personnel portion 2 are fixed, fixed part 10 and 2 axial fixings of reposition of redundant personnel portion, reposition of redundant personnel portion 2 and 3 axial fixings of drainage portion. Further, the fixing portion 10, the flow dividing portion 2 and the drainage portion 3 are integrally formed, and are cylindrical bodies, i.e., cylinders, preferably cylinders, having through holes formed along the central line direction thereof. The material of the drainage device 100 is graphite with low price, preferably isostatic graphite, and may be molybdenum or titanium with high cost. An internal thread 11 for fixed connection is arranged on the inner side wall of the fixing part 10, and the internal thread 11 extends along the central line direction of the fixing part 10; external threads may be provided on the outer sidewall of the fixing portion 10 as needed. Set up in the lateral wall of reposition of redundant personnel portion 2 along the reposition of redundant personnel chamber 5 that circumference extends, reposition of redundant personnel chamber 5 is for encircling the annular cavity that is of a week along reposition of redundant personnel 2 central lines, and reposition of redundant personnel chamber 5 is located the below of internal thread 11 to with reposition of redundant personnel 2 concentric lines. The air inlet portion 1 is disposed inside the flow dividing portion 2, and as shown in fig. 12 and 13, the air inlet portion 1 and the flow dividing portion 2 are integrally formed to avoid the problem that the graphite members are not easily fixedly connected. An air inlet hole 4 for carrier gas to flow into is arranged in the air inlet part 1, the central line of the air inlet hole 4 is parallel to the central line of the flow dividing part 2, and the opening of the air inlet hole 4 is upwards arranged according to the requirement. The air inlet hole 4 is communicated with the flow dividing cavity 5 through a communicating air passage 8. The communicating air duct 8 is arranged along the clockwise direction (seen from top to bottom), as shown in fig. 13, one end part of the communicating air duct 8 is tangentially communicated with the air inlet hole 4, and the other end part is tangentially communicated with the side wall of the diversion cavity 5, as shown in fig. 13, so that the carrier air flow in the communicating air duct 8 flows into the diversion cavity 5 along the clockwise direction.

The air inlet part 1 can also be arranged outside the flow dividing part 2 (not shown in the figure), and the air inlet part 1 and the flow dividing part 2 are integrally formed so as to avoid the problem that graphite parts are difficult to be fixedly connected. An air inlet hole 4 for carrier gas to flow into is arranged in the air inlet part 1, the central line of the air inlet hole 4 is parallel to the central line of the flow dividing part 2, and the opening of the air inlet hole 4 is upwards arranged or downwards arranged according to requirements. One end part of the air inlet hole 4 is communicated with the diversion cavity 5 through a communicating air passage 8, one end part of the communicating air passage 8 is communicated with the air inlet hole 4 in a tangent mode, the other end part of the communicating air passage 8 is communicated with the side face of the diversion cavity 5 in a tangent mode, and carrier gas flow in the communicating air passage 8 flows into the diversion cavity 5 in a clockwise direction (seen from top to bottom). In addition, the central line of the air inlet hole 4 and the central line of the flow dividing part 2 can also be vertically arranged, one end of the air inlet hole 4 is tangentially communicated with the flow dividing cavity 5, and the opening at the other end of the air inlet hole 4 is arranged at the left side or the right side of the flow dividing part 2 according to requirements.

Set up 4 drainage air flue 6 in the lateral wall of drainage portion 3, as shown in fig. 13, 4 drainage air flue 6 surround the central line evenly distributed of drainage portion 3, as shown in fig. 13-15, this drainage air flue 6 is followed cylindric helix downwardly extending from the lower terminal surface of diversion chamber 5, and the central line of drainage air flue 6 extends along the helix direction downwardly extending promptly to coincide with this helix. The helix is located the lateral wall of drainage portion 3, and the helix is rotatory along the clockwise (when looking down from the top), and is the same with the flow direction of carrier gas air current in the intercommunication air flue 8, and helix and drainage portion 3 are coaxial. And the air inlet at the upper end part of the drainage air passage 6 is communicated with the lower end surface of the flow dividing cavity 5, and the air outlet at the lower end part is positioned at the lower end of the drainage part 3.

The drainage air passage 6 and the communication air passage 8 are arranged along the same spiral direction, the communication air passage 8 is respectively communicated with the air inlet hole 4 and the flow dividing cavity 5 in a tangent mode, and smooth transition is respectively carried out at the communication positions. The air flue of mode overall arrangement makes the direction that carrier gas flowed in the reposition of redundant personnel intracavity the same with the direction that carrier gas flowed in drainage air flue, can reduce the resistance of carrier gas circulation, reduces the energy loss of carrier gas, makes the carrier gas keep higher kinetic energy, gets into reposition of redundant personnel chamber 5, and the carrier gas is at reposition of redundant personnel chamber 5 internal rotation, has longer flow, is favorable to the carrier gas more evenly to flow into in drainage air flue 6. The circulation resistance met by the circulation of the carrier gas through the air inlet hole 4, the communication air passage 8, the shunt cavity 5 and the drainage air passage 6 is small, the kinetic energy loss is less, the carrier gas still has high energy when flowing to the air outlet of the drainage air passage 6, so that the carrier gas has high emergent speed, the emergent carrier gas flow generates large carrier gas stress on the liquid silicon, the liquid silicon is promoted to rotate, and a strong rotating flow field is generated in the liquid silicon.

In application, as shown in fig. 1 and 11, the drainage device 12 of the prior art includes a graphite tube 123, a coupling nut 121 and a drainage tube 122 which are axially connected in sequence. The upper end of the delivery tube 122 is provided with external threads which are matched with the internal threads of the coupling nut 121. The upper end of the guide pipe 122 penetrates through a through hole in the middle of the top insulation board 60 of the insulation cage and is axially assembled and fastened with a matching nut 121 arranged above the top insulation board 60, and the lower end of the guide pipe 122 is provided with an external thread matched with the internal thread 11 of the drainage device 100. The drainage device 100 and the guide pipe 122 are axially and tightly connected through the internal thread and the external thread, and the air outlet at the lower end of the drainage device 100 is opposite to the silicon material in the crucible. The gas pipe 50 is arranged in the drainage device 12 in the prior art, as shown in fig. 11, the upper end of the gas pipe 50 is communicated with the existing gas inlet pipe (not shown) of the carrier gas on the ingot furnace, and the lower end is communicated with the gas inlet hole 4 of the drainage device in the invention. The drainage device of the invention is directly assembled at the lower end of the drainage tube 122 of the drainage device 12 in the prior art, only external threads are required to be arranged at the lower end part of the drainage tube, other parts are not required to be modified, the modification is more convenient, and the cost is lower.

Embodiment 3

The invention relates to a drainage device for changing the flow direction of carrier gas, which is shown in figures 18 and 19: the drainage device 100 includes a fastening portion 10, an air intake portion 1, a flow dividing portion 2, and a drainage portion 3. The drainage device 100 is made of molybdenum, and high-temperature resistant materials such as titanium with high cost can also be used. The fastening portion 10 and the flow dividing portion 2 are each a columnar body provided with a through hole along the centerline direction thereof, i.e., a cylinder, preferably a cylinder. The fastening portion 10 and the top of the flow dividing portion 2 are axially fixed. The inner side wall of the fastening part 10 is provided with an internal thread 11 along the center line direction of the fastening part 10, and the outer side wall thereof may be provided with an external thread as required. The flow dividing part 2 is an annular cylindrical closed cavity and mainly comprises an inner side wall, an outer side wall, an upper end wall and a lower end wall; the inner side wall and the outer side wall are cylindrical, and the inner side wall is nested in the outer side wall and shares the same center line. The inner side wall, the outer side wall, the upper end wall and the lower end wall form a flow dividing cavity 5 of the flow dividing part 2. The air inlet part 1 is an air inlet pipe with an air inlet hole 4 arranged therein and is arranged inside the flow dividing part 2, as shown in fig. 19 and 20, the air inlet pipe is fixed with the inner side wall of the flow dividing part 2, the central line of the air inlet hole 4 of the air inlet pipe is parallel to the central line of the flow dividing part 2, and the air inlet of the air inlet hole is arranged upwards as required. The air inlet 4 of intake pipe and the reposition of redundant personnel chamber 5 of reposition of redundant personnel portion 2 are linked together through communicating pipe 9 within a definite time, and communicating pipe 9 embeds there is communicating air flue 8, and communicating pipe 9 (also communicate air flue 8) sets up along clockwise (from the top down) direction, as shown in fig. 20. One end of the communicating pipe 9 is tangentially communicated with the air inlet 4 of the air inlet pipe and is fixed with the air inlet pipe, and the other end of the communicating pipe is tangentially communicated with and fixed with the side wall of the diversion chamber 5 of the diversion part 2, as shown in fig. 20, so that the carrier gas airflow in the communicating pipe 9 flows into the diversion chamber 5 of the diversion part 2 along the clockwise direction (seen from top to bottom).

The intake portion 1 may also be provided outside the flow dividing portion 2 (not shown in the drawings). The central line of the air inlet hole 4 of the air inlet pipe is parallel to the central line of the flow dividing part 2, and the opening of the air inlet hole 4 is arranged upwards or downwards according to the assembly requirement. One end of an air inlet 4 of the air inlet pipe is communicated with the shunting cavity 5 of the shunting part 2 through a communicating pipe 9; one end of the communicating pipe 9 is tangentially communicated with an air inlet 4 of the air inlet pipe and is fixed with the air inlet pipe, and the other end of the communicating pipe is tangentially communicated with the side wall of the shunting cavity 5 of the shunting part 2 and is fixed with the shunting part 2. In addition, the central line of the air inlet hole 4 of the air inlet pipe and the central line of the flow dividing part 2 can also be vertically arranged, the air inlet hole 4 of the air inlet pipe is tangentially communicated with the flow dividing cavity 5 of the flow dividing part 2, and the air inlet of the air inlet hole 4 is positioned on the left side or the right side of the flow dividing part 2 as required.

The drainage part 3 comprises 4 drainage air pipes 7, a drainage air passage 6 is arranged in each drainage air pipe 7, and the drainage air pipes 7 are used for changing the flow direction of carrier air flow. As shown in fig. 19, 4 drainage tubes 7 (i.e., drainage air channels 6) are uniformly distributed around the axial line of the drainage portion 3, and the number of the drainage tubes 7 may be 2, 3, or more than 5. The drainage air pipe 7 (namely the drainage air passage 6) is distributed under the flow dividing part 2 along a cylindrical spiral line, namely the central line of the drainage air pipe 7 extends downwards along the spiral line direction and is superposed with the spiral line. The helix is located under the lower end wall of the flow dividing part 2, the helix rotates clockwise (when viewed from top to bottom), the direction of the helix is the same as that of the carrier gas flow in the communicating pipe 9, and the helix and the flow dividing part 2 are coaxial. The air inlet at the upper end part of the air guide pipe 7 is communicated and fixed with the lower end wall of the flow dividing cavity 5, and the air outlet end at the lower end part of the air guide pipe 7 is positioned below the lower end wall of the flow dividing part 2. The air outlets of the air guide pipes 7 are uniformly distributed around the center line of the flow dividing part 2 along the circumferential direction at the same angular direction, as shown in fig. 19.

The drainage air pipe 7 (namely the drainage air passage 6) and the communicating pipe 9 (the communicating air passage 8) are arranged along the same spiral direction, the communicating pipe 9 is respectively communicated with the air inlet 4 of the air inlet pipe and the flow dividing cavity 5 of the flow dividing part 2 in a tangent mode, and smooth transition is respectively carried out at the communicated positions. The air flue distributed in such a way enables the flowing direction of the carrier gas in the shunting cavity 5 to be the same as the flowing direction of the carrier gas in the drainage air pipe 7, can reduce the flowing resistance of the carrier gas, enables the carrier gas to keep higher kinetic energy, enters the shunting cavity 5, rotates in the shunting cavity 5, has a longer flow path, and is beneficial to the carrier gas to uniformly flow into the drainage air flue 6 of the drainage air pipe 7. The flow resistance met by the carrier gas through the air inlet 4 of the air inlet pipe, the communication air passage 8 of the communication pipe 9, the shunt cavity 5 and the drainage air passage 6 of the drainage air pipe 7 is small, the kinetic energy loss is small, the carrier gas still has high energy when flowing to the air outlet of the drainage air passage 6 of the drainage air pipe, so that the carrier gas has high emergent speed, the emergent carrier gas flow generates high carrier gas stress to liquid silicon, the liquid silicon flow is promoted, and a strong rotating flow field is generated in the liquid silicon.

In use, as shown in fig. 1 and 18, the prior art drainage device 12 includes an axially assembled graphite tube 123, a coupling nut 121, and a delivery tube 122. The upper end of the delivery tube 122 is provided with external threads which are matched with the internal threads of the coupling nut 121. The upper end of the guide pipe 122 penetrates through a through hole in the middle of the top insulation board 60 of the insulation cage and is fastened with a matching nut 121 arranged above the top insulation board 60, and the lower end of the guide pipe 122 is provided with an external thread matched with the internal thread 11 of the drainage device 100. The drainage device 100 and the guide pipe 122 are axially and tightly connected through the internal thread and the external thread, and the lower end of the drainage device 100 is opposite to the silicon material in the crucible. The drainage device is directly assembled at the lower end of the drainage tube 122 of the drainage device 12 in the prior art, only external threads are required to be arranged at the lower end part of the drainage tube 122, other parts are not required to be modified, and the modification cost is lower.

The position of the air outlet of the drainage air passage 6 below the diversion cavity 5 and the emergent direction of the carrier gas flow at the outlet of the drainage air passage 6, namely the tangential direction of the central line of the drainage air passage 6 at the outlet, are designed by changing the pitch and the radius of the spiral line of the outlet section of the drainage air passage 6. When the pitch of the spiral line of the outlet section of the drainage air passage 6 is gradually reduced and the radius is not changed, the air outlet of the drainage air passage 6 is positioned right below the lower end surface of the flow dividing part 2 and evenly distributed around the central line of the flow dividing part 2 along the circumferential direction according to the same-direction angular directions, as shown in fig. 7, that is, the signs of the tangent line of the central line of the drainage air passage 6 at the outlet and the direction angle between the radii are the same, and the sign is positive or negative. The included angle (the included angle between the tangent line and the surface normal) between the tangent line (namely the emergent direction of the carrier gas) of the central line of the drainage air channel 6 at the outlet and the lower end surface (parallel to the liquid silicon surface, namely the liquid silicon surface) of the flow dividing part 2 is gradually increased, and the contact area between the emergent carrier gas flow and the liquid silicon surface is gradually increased; when the screw pitch of the spiral line at the air outlet of the drainage air passage 6 is close to the aperture of the drainage air passage 6, the included angle between the tangent line of the central line at the outlet of the drainage air passage 6 and the lower end surface (namely the liquid silicon surface) of the shunt part 2 is close to 90 degrees, namely the tangent line of the central line at the outlet of the drainage air passage 6 and the lower end surface of the shunt part 2 are close to be parallel, the emergent carrier gas flow is close to be parallel to the liquid silicon surface at the moment, the contact area between the emergent carrier gas flow and the liquid silicon surface is the largest, the amount of carrier gas contacting the unit area of the carrier gas flow blowing area of the liquid silicon is the smallest, the heat taken away by the carrier gas flow from the unit area of the area is the smallest, the temperature reduction amplitude of the liquid silicon in the carrier gas flow blowing area is the smallest, the supercooling. In addition, the screw pitch and radius of the spiral line of the outlet section of the drainage air channel 6 can be changed according to requirements, the screw pitch of the lower end part of the spiral line is gradually reduced, and the radius is gradually increased, so that the air outlet of the drainage air channel 6 is positioned at the lower end of the extending surface of the outer side surface of the flow splitting part 2, and also can be positioned outside the extending surface of the outer side surface of the flow splitting part 2, as shown in fig. 9 and fig. 16, so as to conveniently design the outlet direction of the drainage air channel 6, optimize the area where carrier gas flow is blown and jetted on the surface of liquid silicon, such as the middle position between the center of the liquid silicon and the edge of the liquid silicon, and generate a stronger rotating flow field in the liquid silicon under the condition of certain carrier gas pressure, so that impurities.

The drainage device is provided with 4 drainage air passages (drainage air pipes) for changing the flow direction of carrier gas, the 4 drainage air passages are uniformly distributed around the central line of the drainage device, air outlets of the 4 drainage air passages respectively face different areas of the surface of the liquid silicon, and 4 blowing and ejecting areas of the carrier gas flow are formed on the surface of the liquid silicon. The carrier gas is divided into 4 carrier gas flows through 4 drainage gas passages of the drainage device, the 4 carrier gas flows respectively and dispersedly blow 4 areas of the surface of the liquid silicon, the 4 areas blown by the emergent carrier gas flows are uniformly distributed around the center of the liquid silicon, the carrier gas amount contacted with each blowing area is only 1/4 of the gas transmission amount, the emergent carrier gas flows obliquely blow the surface of the liquid silicon, the contact surface of the emergent carrier gas flows and the surface of the liquid silicon is larger than the cross section of the jet carrier gas, the heat taken away by each carrier gas flow from the liquid silicon in the blowing area is smaller than 1/4 of concentrated vertical blowing in the prior art, the local temperature reduction amplitude of the liquid silicon in the areas blown by the carrier gas flows is greatly reduced, the supercooling degree is reduced, the nucleation probability of impurities caused by the carrier gas in the liquid silicon is reduced, and the formation of the impurities promoted by the carrier gas is reduced. The included angle between the emergent carrier gas flow and the surface of the liquid silicon (the included angle between the emergent carrier gas flow and the normal line of the surface of the liquid silicon) is changed by adjusting the direction of the gas outlet of the drainage gas channel, the included angle is increased, the contact area between the carrier gas flow and the surface of the liquid silicon can be increased, and the contact area is increased to be the reciprocal multiple of the cosine value of the included angle of the cross section area of the carrier gas flow. The inclined blowing and jetting mode is combined with the dispersed blowing and jetting mode of the plurality of drainage air passages, so that the contact area between the carrier gas and the surface of the liquid silicon can be effectively increased, and less heat can be taken away by the carrier gas flow from the unit area of the liquid silicon in the blowing and jetting area. The included angle between the emergent carrier gas flow and the surface of the liquid silicon is properly reduced, such as 30-40 degrees, the emergent carrier gas flow obliquely blows the surface of the liquid silicon, the amount of carrier gas contacting the liquid silicon in a unit area of a carrier gas flow blowing area is slightly increased, but the emergent carrier gas flow generates larger carrier gas stress for driving laminar flow to the liquid silicon, and the carrier gas stress drives the liquid silicon on the surface layer to flow; the area blown by the carrier gas flow is distributed around the center of the liquid silicon, and the stress of the carrier gas is distributed around the center of the liquid silicon, so that a strong rotating flow field which flows in the circumferential direction is formed in the liquid silicon. The rotating flow field is beneficial to conveying the floating impurities on the surface of the liquid silicon to the edge of the liquid silicon, so that the influence of the floating impurities on the yield of crystals is reduced, and the yield of the crystals is improved; meanwhile, the method is also beneficial to conveying impurities in the liquid silicon to the surface and promoting the volatilization of the impurities; under the combined action of the natural convection flow field and the rotary flow field, the liquid silicon is beneficial to the transportation and the uniform distribution of impurities in the liquid silicon, the radial resistivity of the crystal is more uniform, and the quality of the crystal is further improved.

The drainage device comprises an air inlet part 1, a flow dividing part 2 and a drainage part 3, wherein the flow dividing part 2 and the drainage part 3 are hollow cylinders, and a drainage air channel 6 is arranged in the side wall (or a drainage air pipe) of the drainage part 3. The intake portion 1 may be provided inside the flow dividing portion 2 or outside the flow dividing portion 2. When the air inlet part 1 is arranged in the flow dividing part 2, although the air inlet part 1 shields the view field of the drainage device leading to the ingot furnace, the shielded area is very small and is less than one fourth of the view field area, as shown in fig. 5, 13 and 20, the observation of the state in the furnace, the insertion of the crystal detecting rod and the detection of the state of the silicon material by the infrared detector are not influenced. And secondly, the furnace body of the existing ingot furnace is not required to be modified, for example, through holes through which the gas conveying pipes 50 penetrate are not required to be formed in the double-layer water-cooled steel furnace body of the polycrystalline ingot furnace and the heat insulation plate of the heat insulation cage, and the communication layout of the gas conveying pipes 50 and the drainage device is also simplified. The gas pipe 50 is arranged in the drainage device 12 in the prior art, the lower end of the gas pipe 50 is communicated with the gas inlet hole 4 of the drainage device 100, and the upper end is communicated with the carrier gas inlet below the observation window on the top of the furnace. The material of the gas pipe 50 is molybdenum, and can also be titanium. When setting up air inlet portion 1 in the outside of reposition of redundant personnel portion 2, air inlet portion 1 will not have any the sheltering from to the visual field that accesss to in the ingot furnace in drainage device 100, but need reform transform the furnace body of current ingot furnace, if reform transform the heated board of the steel furnace body of ingot furnace and thermal-insulated cage, its degree of difficulty is big, and is with high costs. Therefore, the flow guiding device 100 of the invention has a view field leading to the interior of the ingot furnace, and the state of the silicon material in the furnace can be seen from the observation window at the top of the furnace through the flow guiding device 100 of the invention, thereby facilitating the operation of the furnace; an infrared detector arranged right above the drainage device 100 can detect the state of the silicon material in the furnace through an observation window and the drainage device, and the automatic crystal growth process is smoothly carried out; the crystal measuring bar can be inserted into the ingot furnace through the drainage device 100, and the growth speed of the crystal is convenient to measure.

The exit direction of the carrier gas at the gas outlet of the flow guiding gas channel, that is, the tangential direction of the central line of the flow guiding gas channel at the outlet, as shown in fig. 21, the included angle between the tangential line of the central line of the flow guiding gas channel at the outlet and the lower end surface of the flow guiding device (the included angle between the tangential line and the surface normal) is labeled as β, the included angle between the exit direction of the carrier gas flow and the surface normal of the liquid silicon is also labeled as β, the center of the contact surface between the exit carrier gas flow and the surface of the liquid silicon is labeled as a, the distance from the outlet of the flow guiding gas channel to the surface of the liquid silicon is labeled as h, the center position of the surface of the liquid silicon is labeled as O, the distance from the center O of the surface of the liquid silicon to the center a of the contact surface of the carrier gas flow and the surface of the liquid silicon is labeled as a, the radius of the spiral line at the outlet of the flow guiding gas channel is labeled as r, the relationship between a, r, h, β can be approximately expressed as tg β (a-r)/h, if it is required that the liquid silicon generates a stronger rotation at the exit direction of the carrier gas flow channel, when the outlet is designed, the liquid silicon outlet is designed to the exit position of the silicon, the liquid carrier gas flow guiding gas flow channel is designed to be away from the center of the silicon, the liquid silicon surface, the silicon outlet, the exit gas flow field is increased, the silicon surface, the silicon is increased, the exit of the silicon carrier gas flow guiding gas flow is increased, the silicon carrier gas flow is increased, the silicon surface is increased, the silicon surface of the silicon surface is increased, the silicon surface is increased.

The working principle of the drainage device is that a gas conveying pipe conveys carrier gas to a gas inlet hole of the drainage device, the carrier gas flows into a flow dividing cavity of the drainage device through the gas inlet hole and rotates in the flow dividing cavity, then the carrier gas flows into a plurality of drainage gas passages which are uniformly distributed from the lower end of the flow dividing cavity and then exits from a gas outlet of the drainage gas passages, and the exiting carrier gas flow obliquely blows the surface of liquid silicon, the plurality of drainage gas passages enable the carrier gas to dispersedly blow different regions of the surface of the liquid silicon, so that the contact area of the carrier gas and the surface of the liquid silicon is effectively increased, the contact amount of the carrier gas and the liquid silicon surface is reduced, the contact amount of the carrier gas on a unit area is reduced, the carrier gas is intensively blown to the middle region of the surface of the liquid silicon in the prior art, the carrier gas takes away a large amount of heat from the region, the temperature of the liquid silicon in the region is greatly reduced, the supercooling degree is enhanced, the supersaturation degree is promoted, the impurity of supersaturation nucleation and impurities are generated and impurities are generated in the generation of the crystal impurity-carrying out angle of the liquid crystal.

Compared with the prior art, the invention has the following technical progress.

1) The drainage device is provided with a view field leading to the interior of the ingot furnace, and when the air inlet part is arranged outside the flow dividing part, the view field leading to the interior of the ingot furnace in the drainage device is not shielded; when the air inlet part is arranged in the flow dividing part, although the air inlet part shields the view field, the shielded area is less than one fourth of the area of the view field, and the flow guiding device still has the view field leading to the ingot furnace; therefore, the state in the ingot furnace can be smoothly observed through the drainage device, and the furnace operation is convenient; inserting a crystal measuring bar through a drainage device, and measuring the growth speed of the crystal; the infrared detector can detect the state of the silicon material in the ingot furnace through the drainage device, and the automatic crystal growth process can be smoothly carried out.

2) The local supercooling caused by the carrier gas in the liquid silicon is reduced, the carrier gas is divided into a plurality of carrier gas flows by a plurality of drainage gas passages of the drainage device, the plurality of carrier gas flows are scattered and obliquely blown to different areas of the surface of the liquid silicon, the contact area between the carrier gas and the surface of the liquid silicon is effectively increased, the amount of the carrier gas which is contacted on the unit area of the liquid silicon in the carrier gas blowing area is reduced, the heat taken away by the carrier gas flow on the unit area is reduced, and the local temperature reduction amplitude of the area caused by the carrier gas flow is reduced, so that the local supercooling caused by the carrier gas in the liquid silicon and the promoted growth of impurity nucleation are reduced or even avoided.

3) The crystal quality is improved, a plurality of drainage air passages of the drainage device are uniformly distributed around the central line of the drainage device, carrier gas is divided into a plurality of carrier gas flows through the drainage air passages, the carrier gas flows are obliquely blown to different areas of the surface of the liquid silicon respectively, the blown areas of the carrier gas flows are distributed around the center of the surface of the liquid silicon, the carrier gas flows generate carrier gas stress for driving laminar flow to the liquid silicon, and the carrier gas stress drives the liquid silicon to flow to form a rotary flow field flowing around the center of the liquid silicon. The rotating flow field is beneficial to conveying the floating impurities on the surface of the liquid silicon to the edge of the liquid silicon, so that the influence of the floating impurities on the yield of crystals is reduced, and the yield of the crystals is improved; the method is also beneficial to conveying impurities in the liquid silicon to the surface of the liquid silicon and accelerating the volatilization of the impurities in the liquid silicon; under the combined action of the natural convection flow field and the rotary flow field, the liquid silicon is beneficial to the transportation and the uniform distribution of impurities in the liquid silicon, the local enrichment of the impurities is avoided, the radial resistivity distribution of the crystal is more uniform, and the quality of the crystal is further improved. .

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the foregoing description only for the purpose of illustrating the principles of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims, specification, and equivalents thereof.

Claims (10)

1. The utility model provides a change drainage device of carrier gas flow direction which characterized in that: including fixed connection's air inlet, reposition of redundant personnel portion and drainage portion in proper order, the built-in inlet port that is used for the carrier gas to flow in of air inlet, the built-in reposition of redundant personnel chamber of reposition of redundant personnel portion, drainage portion comprises two drainage air flues that are used for changing the carrier gas flow direction at least, the inlet port with reposition of redundant personnel chamber intercommunication, the air inlet and the reposition of redundant personnel chamber intercommunication of drainage air flue, helix direction downwardly extending is followed to the export section of drainage air flue, and the gas outlet is according to the angular distribution of equidirectional along circumference, reposition of redundant personnel portion and drainage portion are located.

2. The flow guide device for changing the flow direction of a carrier gas according to claim 1, wherein: the flow distribution part and the drainage part are integrally formed and are cylindrical bodies provided with through holes along the central line direction of the flow distribution part, and annular flow distribution cavities extending along the circumferential direction are arranged in the side wall of the flow distribution part; the lateral wall of drainage portion sets up the drainage air flue that extends downwards from the lower extreme face of reposition of redundant personnel chamber in, and the gas outlet of drainage air flue is located the lower extreme of drainage portion.

3. The flow guide device for changing the flow direction of a carrier gas according to claim 2, wherein: the flow dividing part and the drainage part are columnar bodies provided with through holes along the central line direction of the flow dividing part, the flow dividing part comprises a first flow dividing part and a second flow dividing part which are fixedly connected in the axial direction, and the second flow dividing part and the drainage part are integrally formed; a first shunting cavity with an annular lower end surface opening and extending along the circumferential direction is arranged in the side wall of the lower end part of the first shunting part, and the air inlet is communicated with the first shunting cavity; a second flow dividing cavity which extends along the circumferential direction and is provided with an opening at the upper end face is arranged in the side wall of the upper end part of the second flow dividing part, the second flow dividing cavity corresponds to the first flow dividing cavity, and the first flow dividing cavity and the second flow dividing cavity form the flow dividing cavity; set up the drainage air flue that extends downwards from second reposition of redundant personnel chamber lower extreme face in the lateral wall of drainage portion, the gas outlet of drainage air flue is located the lower extreme of drainage portion.

4. A flow guide device for changing the flow direction of a carrier gas according to claim 2 or 3, wherein: the air inlet is communicated with the flow dividing cavity through a communicating air passage, one end of the communicating air passage is communicated with the air inlet in a tangent mode, and the other end of the communicating air passage is communicated with the side face of the flow dividing cavity in a tangent mode.

5. The flow guide device for changing the flow direction of a carrier gas according to claim 1, wherein: the air inlet part is an air inlet pipe with an internal air inlet hole, and the drainage part comprises a drainage air pipe with a drainage air passage; the flow dividing part is an annular closed cavity mainly formed by an inner side wall, an outer side wall, an upper end wall and a lower end wall, and the inner side wall, the outer side wall, the upper end wall and the lower end wall form the flow dividing cavity; one end of the air inlet pipe is communicated and fixed with the flow dividing cavity; the drainage trachea sets up in the below of reposition of redundant personnel portion, and the air inlet and the reposition of redundant personnel chamber intercommunication of drainage trachea upper end to fixed with drainage portion, the gas outlet of drainage trachea lower extreme is according to the angular distribution of equidirectional along circumference.

6. The flow guide device for changing the flow direction of a carrier gas according to claim 5, wherein: the air inlet pipe is communicated with the shunting cavity of the shunting part through a communicating pipe, one end of the communicating pipe is communicated with the air inlet pipe in a tangent mode and is fixed, and the other end of the communicating pipe is communicated with the side wall of the shunting cavity in a tangent mode and is fixed.

7. The flow guide device for changing the flow direction of a carrier gas according to claims 2 to 6, wherein:

the air inlet part is arranged in the flow dividing part, and the central line of the air inlet hole is parallel to the central line of the flow dividing part; or,

the air inlet part is arranged outside the flow dividing part, and the central line of the air inlet hole is parallel or vertical to the central line of the flow dividing part.

8. The flow guide device for changing the flow direction of a carrier gas according to claim 7, wherein:

the drainage air passage extends along the cylindrical spiral line, the pitch of the spiral line at the air outlet section of the drainage air passage is gradually reduced, and the air outlet of the drainage air passage is positioned right below the lower end face of the flow dividing part; or,

the drainage air flue extends along cylindrical spiral line, the pitch of the spiral line of drainage air flue gas outlet section reduces gradually, the radius increases gradually, and the gas outlet of drainage air flue is located the lower extreme of the lateral wall extending surface of reposition of redundant personnel portion or is located the outside of reposition of redundant personnel portion lateral wall extending surface.

9. The flow guide device for changing the flow direction of a carrier gas according to claim 8, wherein: the number of the drainage air passages is 2, 3 or 4.

10. The flow guide device for changing the flow direction of a carrier gas according to claim 9, wherein: the air inlet part, the flow dividing part and the flow guiding part are made of graphite, molybdenum, tungsten or titanium.