CN202126162U - Silicon powder drying device - Google Patents

Abstract

The embodiment of the utility model discloses a silicon powder drying equipment, which includes a shell surrounding a drying cavity, and the shell is provided with a material inlet, a material outlet, an air inlet and an air outlet connected to the drying cavity. , the outlet is set at the bottom of the shell; the air outlet is set above the feed port, and there is also a cyclone separator on it, and the cyclone separator is located in the drying chamber; the drying chamber corresponds to the feed port A partition is provided; the air inlet is arranged below the feed inlet and communicated with the heating nitrogen source. Since the equipment does not have the process of scrap and cloth when drying silicon powder, therefore, there is no equipment with scrap and cloth, thus simplifying the specific structure of the equipment. Compared with mechanical drying, drying silicon powder by heat exchange is faster and more thorough, which improves the efficiency of equipment drying materials.

Description

Silica powder drying equipment

technical field

The utility model relates to the field of polysilicon preparation, in particular to a silicon powder drying equipment.

Background technique

Polysilicon is the raw material for the preparation of semiconductor devices and solar cells, and is the cornerstone of the global electronics and photovoltaic industries. According to its purity and usage, it can be divided into solar-grade polysilicon and electronic-grade polysilicon. Trichlorosilane (chemical formula SiHCl ₃ ) is the main raw material for producing high-purity polysilicon. When producing polysilicon, pass H ₂ and SiHCl ₃ into the reduction furnace, and the following reaction will occur under high temperature conditions: SiHCl ₃ +H ₂ →Si+3HCl, while the following reaction will occur in the production of trichlorosilane: Si+3HCl→SiHCl ₃ +H ₂ , Si in the above reaction is silicon powder, and the silicon powder required in the process of preparing trichlorosilane must be dry silicon powder, if the silicon powder contains moisture, the silicon powder The water in the powder will react with HCl and trichlorosilane cannot be prepared. Therefore, the silicon powder used in the preparation of trichlorosilane needs to be dried by a drier.

The traditional silica fume dryer basically adopts the steam jacket method. The disadvantage of this method is that the silica fume is not completely dried. For example, the Chinese patent No. 90215264.5, as shown in Figure 1, is a schematic diagram of the structure of a traditional centrifugal fluidized bed dryer, wherein 001 is a feed port; 002 is a screw feeder; 003 is a drop tube; 004 is a Crushing rod; 005 is a pulverizer; 006 is a mandrel; 007 is a sleeve shaft; 008 is a distribution plate; 009 is an air inlet; 010 is an air outlet; 011 is a material outlet; 012 is a drum; ; 014 is a stirrer. This patent discloses a centrifugal fluidized bed dryer, which specifically includes a shell, a feed port 001, a discharge port 011, an air inlet 009, and an air outlet 010; wherein, the feed port 001 is connected through a drop pipe 003 On the top of the fluidized bed, a distribution disc 008 is placed under the drop pipe 003. The distribution disc 008 is fixed on a mandrel 006 driven by a motor. The mandrel 006 is provided with a sleeve shaft 007. Bearings are arranged between them, an agitator 014 is fixed at the lower end of the mandrel 006, and a drum 012 driven by a motor is set on the inner wall of the fluidized bed. Small holes are uniformly and densely distributed on the drum 012, and the air inlet 009 is tangentially connected to the cylindrical fluidized bed. The shell 013 and the air outlet 010 are connected from the outside of the fluidized bed to the central part of the fluidized bed by an elbow. Its working principle is that under the action of the screw feeder 002, the granular wet material enters the feeding pipe 003 from the feeding port 001, and is crushed under the action of the crushing rod 004 and the pulverizer 005 set in the feeding pipe 003, so as to It facilitates the evaporation of water vapor and reaches the rotating distributing pan 008. The distributing pan 008 tangentially and evenly skims the material. Due to the centrifugal force field of the drum 012 rotating in the same direction, the material generates an outward centrifugal force. At the same time, the hot air enters tangentially from the air inlet 009, and then enters the air evenly from the small hole of the drum 012 to the inside of the drum 012. The direction of the incoming wind force is opposite to the direction of the centrifugal force of the material. An annular fluidized belt begins to form in the drum 012, and the granular materials are fluidized and dried. At the same time, through the rotation and agitation of the agitator 014, the annular fluidized zone is continuously harassed periodically to achieve the purpose of intensified drying of the material. The dried material is discharged from the discharge port 011 through the cone of the fluidized bed cloth. The exhaust gas with water vapor is discharged from the air outlet 010 pipe. Due to the working process of the above-mentioned centrifugal fluidized bed, the materials need to be broken and distributed before drying. Therefore, the fluidized bed needs to be equipped with related structures for breaking and distributing the materials, and the structure of the equipment is relatively complicated; and the drying time is relatively long. Long, reduces the drying rate of the material is lower.

For this reason, how to develop a kind of silicon powder drying equipment with simple structure and high drying efficiency has become a technical problem to be solved urgently by those skilled in the art.

Utility model content

In view of this, the utility model provides a silicon powder drying equipment to simplify the structure of the equipment and improve the drying efficiency of the silicon powder.

In order to achieve the above object, the utility model provides the following technical solutions:

A kind of silicon powder drying equipment, comprising a shell that surrounds a drying cavity, the shell is provided with a feed port, a discharge port, an air inlet and an air outlet that communicate with the drying cavity, the The outlet is arranged at the bottom of the housing; the outlet is arranged above the inlet, and a cyclone separator is arranged on it, and the cyclone separator is located in the drying cavity; The drying cavity is provided with a partition corresponding to the feeding port; the air inlet is arranged below the feeding port and communicated with a heating nitrogen source.

Preferably, in the above-mentioned silicon powder drying equipment, a gas distribution plate is arranged in the drying chamber above the air inlet, and the gas distribution plate has a plurality of through holes.

Preferably, in the above silicon powder drying equipment, the through hole is a circular through hole.

Preferably, in the above-mentioned silicon powder drying equipment, the housing includes a separation part, a drying part and a discharge part, wherein the drying part is smoothly connected with the separation part and the discharge part respectively, and the separation part The cross-sectional area of the drying part is larger than that of the drying part, and the cross-section of the discharge part tapers toward the discharge opening.

Preferably, in the above-mentioned silicon powder drying equipment, the air inlet is arranged on the discharge part, the feed inlet is arranged on the drying part, and the gas outlet is arranged on the separation part.

Preferably, in the above-mentioned silicon powder drying equipment, a purge port is further provided at the separation part near the gas outlet, and the purge port is connected to a nitrogen source.

Preferably, in the above silicon powder drying equipment, on-off valves are provided on both the air inlet and the air outlet.

Preferably, in the above silicon powder drying equipment, the feed inlet is provided with a feed valve, and the feed outlet is provided with a discharge valve.

The silicon powder drying equipment in the utility model mainly includes a shell that encloses a drying cavity, and the shell is provided with a feed port, a discharge port, an air inlet and an air outlet that communicate with the drying cavity. , the outlet is arranged at the bottom of the housing; the outlet is arranged above the inlet, and a cyclone separator is also arranged on it, and the cyclone separator is located in the drying chamber In the middle; the drying cavity is provided with a partition corresponding to the feed inlet; the air inlet is arranged below the feed inlet and communicated with the heating nitrogen source. When the above equipment is working, firstly, the hot nitrogen source continuously feeds high-temperature nitrogen into the drying chamber through the air inlet; then the silicon powder that needs to be dried enters the drying chamber through the feeding inlet, and is sent to the partition, and the partition The setting can prolong the contact time between high-temperature nitrogen gas and dry miscellaneous silicon powder, and improve the heat exchange rate between high-temperature nitrogen gas and silicon powder, thereby improving drying efficiency. The silicon powder that needs to be dried evaporates the water on the silicon powder under the action of high-temperature nitrogen, and exhausts the waste gas from the air outlet to the outside of the equipment under the action of the cyclone separator; the dried silicon powder falls to the discharge port, and Discharge from the outlet.

It can be seen from the above description that since the equipment does not have the process of scrap and cloth when drying silicon powder, therefore, there is no equipment with scrap and cloth, thus simplifying the specific structure of the equipment. Moreover, the drying process of the equipment is through the introduction of high-temperature nitrogen gas, so that the high-temperature nitrogen gas exchanges heat with the silicon powder that needs to be dried to vaporize the moisture in the silicon powder, instead of throwing out the moisture through the action of centrifugal force, which further simplifies the process. the structure of the device. Compared with mechanical drying, drying silicon powder by heat exchange is faster and more thorough, which improves the efficiency of equipment drying materials.

In addition, since the equipment is also equipped with a purge port, which is connected to the nitrogen source, when the silicon powder blocks the discharge port and the gas distribution plate, the purge port can be connected to 0.6MPa nitrogen for purging, thereby Can continue to work smoothly.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are only some embodiments of the utility model, and those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the structural representation of the drier of centrifugal fluidized bed in the prior art;

Fig. 2 is the schematic structural representation of the silicon powder drying equipment provided in the utility model embodiment;

Fig. 3 is a schematic diagram of the structure of the distribution plate provided in the embodiment of the present invention;

Fig. 4 is a schematic diagram of the partition structure provided in the embodiment of the present invention;

The labels in the figure indicate: 001 is the feed port; 002 is the screw feeder; 003 is the drop tube; 004 is the crushing rod; 005 is the pulverizer; 006 is the mandrel; 007 is the sleeve shaft; 008 is the distribution plate; 010 is the air outlet; 011 is the discharge port; 012 is the drum; 013 is the fluidized bed shell; 014 is the agitator; 10 is the shell; 11 is the separation part; 12 is the drying part; 13 is the row 100 is the drying chamber; 20 is the feed inlet; 30 is the air inlet; 40 is the air outlet; 50 is the discharge port; 60 is the purge port; 70 is the cyclone separator; 81 is a main board; 82 is a through hole; 90 is a gas distribution plate; 91 is a main board; 92 is a through hole.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

The utility model discloses a silicon powder drying device, which simplifies the structure of the device and improves the drying efficiency of the silicon powder.

As shown in Figure 2, 10 is the shell; 11 is the separation part; 12 is the drying part; 13 is the discharge part; 100 is the drying cavity; 20 is the inlet; 30 is the air inlet; 50 is a discharge port; 60 is a purge port; 70 is a cyclone separator; 80 is a partition plate; 81 is a main board; 82 is a through hole; 90 is a gas distribution plate; 91 is a main board; 92 is a through hole.

The silicon powder drying equipment includes a housing 10 surrounding a drying chamber 100, the housing 10 is provided with a feed port 20, a discharge port 50, an air inlet 30 and an air outlet 40 communicating with the drying chamber 100, The discharge port 50 is arranged at the bottom of the housing 10; the air outlet 40 is arranged above the feed port 20, and a cyclone separator 70 is also arranged on it, and the cyclone separator 70 is located in the drying chamber 100; the drying chamber 100 A partition 80 is provided corresponding to the feed port 20; the gas inlet 30 is provided below the feed port 20 and communicated with a heating nitrogen source (not shown in the figure).

When the above-mentioned equipment is working, firstly, the hot nitrogen source continuously feeds high-temperature nitrogen into the drying chamber 100 through the air inlet 30; The setting of the plate 80 can prolong the contact time between the high-temperature nitrogen gas and the silicon powder to be dried, and improve the heat exchange rate between the high-temperature nitrogen gas and the silicon powder, thereby improving the drying efficiency. The silicon powder that needs to be dried evaporates the water on the silicon powder under the action of high-temperature nitrogen, and discharges the waste gas from the gas outlet 40 to the outside of the equipment under the action of the cyclone separator 70; the dried silicon powder falls to the discharge port 50, and discharged from the outlet 50.

It can be seen from the above description that since the equipment does not have scrap and cloth process when drying silicon powder, therefore, there is no equipment with scrap and cloth, thus simplifying the specific structure of the equipment. Moreover, the drying process of the equipment is through the introduction of high-temperature nitrogen gas, so that the high-temperature nitrogen gas exchanges heat with the silicon powder that needs to be dried to vaporize the moisture in the silicon powder, instead of throwing out the moisture through the action of centrifugal force, which further simplifies the process. the structure of the device. Compared with mechanical drying, drying silicon powder by heat exchange is faster and more thorough, which improves the efficiency of equipment drying materials.

The partition 80 in the embodiment of the utility model can be separately arranged inside the drying cavity 100, and can also be integrally assembled into a specific shape to be placed inside the drying cavity 100, as shown in Figure 3, the partition in the embodiment of the utility model The plates 80 form a cube structure, and the main plate 81 of each partition 80 is provided with a through hole 82, which can be a circular hole, a long hole, etc., and the arrangement of the through holes can be arranged alternately or side by side. The layout is not repeated here.

In order to make the high-temperature gas passed into the air inlet 30 fully contact with the silicon powder, a gas distribution plate 90 is arranged in the drying chamber 100 and above the air inlet 30, and the gas distribution plate 90 includes a main board 91 on which a There are a plurality of through holes 92 as shown in FIG. 4 . Wherein, in the embodiment of the utility model, the number, shape, material and layout of the through holes are not limited. However, strip-shaped holes or circular holes can be selected for processing convenience. Preferably, the above-mentioned through holes 92 are circular through holes; their arrangement can be neatly arranged or staggered.

In order to avoid the waste of silicon powder when the cyclone separator 70 separates silicon powder and waste gas, for the convenience of description, the housing 10 is divided into three parts according to different purposes in the embodiment of the utility model. Specifically, the housing 10 includes a separation part 11 , drying section 12 and discharge section 13, wherein, drying section 12 is connected smoothly with separation section 11 and discharge section 13 respectively, and the cross-sectional area of separation section 11 is larger than the cross-sectional area of drying section 12, and the section area of discharge section 13 Tapers toward the discharge opening. The larger structure of the separation part 11 can make the waste gas stay longer in the drying chamber 100, so the silicon powder carried in the waste gas will have enough time to fall on the corresponding shell wall of the separation part 11, and Finally, it flows back to the drying chamber 100 corresponding to the drying section 12 .

When the housing 10 with the above-mentioned three-part structure is adopted, the air inlet 30 is arranged on the discharge part 13 , the feed inlet 20 is arranged on the drying part 12 , and the air outlet 40 is arranged on the separation part 11 .

In addition, in order to prevent silicon powder from clogging the gas distribution plate 90 and the discharge port 50, the separation part 11 is provided with a purge port 60 near the gas discharge port 40, and the purge port 60 is connected to a nitrogen source. When the gas distribution plate 90 or the discharge port 50 is blocked, 0.6MPa nitrogen gas is connected to the purge port 60 for purging, so as to continue to work smoothly.

In addition, in order to facilitate the control of the intake air volume and air output volume, both the air intake port 30 and the air outlet port 40 are provided with on-off valves. The power during drying is controlled by the air intake and output.

In addition, in order to obtain more thoroughly dried silicon powder, in the embodiment of the present utility model, the feed port 20 is provided with a feed valve, and the discharge port 50 is provided with a discharge valve. When drying, close the discharge valve, open the feed valve, and transport a certain amount of silicon powder through the feed port 20, and then close the feed valve. When it is detected that the dew point in the air outlet 40 is close to the inlet dew point, it means that the silicon powder has been thoroughly dried, and at this time, the discharge valve is opened for discharge.

The above description of the disclosed embodiments enables those skilled in the art to realize or use the utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims (8)

1. silica powder drying equipment; Comprise the housing (10) that surrounds dry cavity (100); Said housing (10) is provided with the charging aperture (20) that is connected with said dry cavity (100), discharging opening (50), air inlet (30) and gas outlet (40), and said discharging opening (50) is arranged on the bottom of said housing (10); It is characterized in that said gas outlet (40) are arranged on the top of said charging aperture (20), and also be provided with cyclone separator (70) on it, said cyclone separator (70) is arranged in said dry cavity (100); Said dry cavity (100) is provided with dividing plate (80) with said charging aperture (20) corresponding section; Said air inlet (30) is arranged on said charging aperture (20) below, and is connected with the heated nitrogen source.

2. silica powder drying equipment as claimed in claim 1 is characterized in that, is provided with gas distribution grid (90) in the said dry cavity (100) and above being positioned at said air inlet (30), has a plurality of through holes (92) on the said gas distribution grid (90).

3. silica powder drying equipment as claimed in claim 2 is characterized in that, said through hole (92) is a manhole.

4. like each described silica powder drying equipment of claim 1 to 3; It is characterized in that; Said housing (10) comprises separated part (11), drying section (12) and discharge portion (13), wherein, said drying section (12) respectively with said separated part (11) and smooth connection of discharge portion (13); And the sectional area of the said drying section of the sectional area ratio of said separated part (12) is big, and the cross section of said discharge portion (13) is to said discharge gate convergent.

5. silica powder drying equipment as claimed in claim 4 is characterized in that, said air inlet (30) is arranged in the said discharge portion (13), and said charging aperture (20) is arranged on the drying section (12), and said gas outlet (40) are arranged on the said separated part.

6. silica powder drying equipment as claimed in claim 5 is characterized in that, said separated part is located also to be provided with near said gas outlet (40) and purged mouthful (60), and said purging mouthful (60) links to each other with source nitrogen.

7. like each described silica powder drying equipment of claim 1 to 3, it is characterized in that, be provided with switch valve on said air inlet (30) and the said gas outlet (40).

8. like each described silica powder drying equipment of claim 1 to 3, it is characterized in that said charging aperture (20) is provided with inlet valve, said discharging opening (50) is provided with bleeder valve.

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