KR20130053720A - Apparatus and method for recovery of silane - Google Patents

Abstract

PURPOSE: An apparatus and a method for collecting silane are provided to collect and reuse liquid silane through a primary droplet step, a cooling step, and a secondary droplet step without directly releasing silane gas, and to enhance economic efficiency. CONSTITUTION: An apparatus for collecting sialne comprises a housing(10), a gas inlet unit(20), a primary cyclone droplet unit(30), a cooling space part(40), a secondary droplet unit(50), a filter(60), a gas outlet unit(70), and a silane liquid collection unit(80). The housing is a silane collection device for collecting silane gas in a liquid phase. The primary cyclone droplet unit liquefies the silane gas which flows in through the gas inlet unit. The cooling space part lowers temperature of the silane gas by a cooling device. The secondary droplet unit liquefies the silane gas which passes through the cooling space unit. The filter filters the microsialne droplets and aggregates. The gas outlet unit discharges silane-removed gas. The silane liquid collection unit connects the silane liquid.

Description

Silane recovery device and recovery method {APPARATUS AND METHOD FOR RECOVERY OF SILANE}

The present invention relates to a silane recovery apparatus and a recovery method, and more particularly, to a silane recovery apparatus and recovery for efficiently recovering and recycling silane gas, a by-product generated in the manufacturing process of polysilicon, which is a raw material of a solar cell. It is about a method.

The present invention relates to a silane recovery apparatus and a recovery method, and more particularly, to a silane recovery apparatus and recovery for efficiently recovering and recycling silane gas, a by-product generated in the manufacturing process of polysilicon, which is a raw material of a solar cell. It is about a method.

In general, when manufacturing a solar cell, a thin slice of crystalline silicon called poly silicon is sliced to make a wafer, and various processes are added to the wafer to form a semiconductor or a solar cell. The polysilicon is basically made of quartz (silicon dioxide = SiO ₂ ), which is made of metallic silicon with high purity using carbon, and made of liquid by removing oxygen with cokes or charcoal, and then solidifying by coagulation. It is made in the form of silicon (Metallurgical-Grade Si; MG-Si) and is produced by various manufacturing methods.

Currently, the siemens process, the most widely used polysilicon production process for semiconductors and solar cells, converts MG-Si (metal grade silicon) into high-purity silane gas and then undergoes precipitation reactions due to pyrolysis and hydrogen reduction of silane materials. The route is a polysilicon manufacturing process developed by Siemens of Germany in the 1950s and is the world's most widely used polysilicon manufacturing process. (1) Metallic silicon is reacted with HCl to form gaseous monosilane (Chlorosiliane). (2) Distilled at room temperature (25 ° C) to form trichlorosilane (TCS) gas. Polysilicon is obtained by reacting a cap-shaped silicon rod with monosilane or trichlorosilane.

In the polysilicon manufacturing process, a gasification process and a reaction byproduct recycling process are performed to obtain silicon (Si) for solar cells. Precipitation of the TCS + H2 reactant gas based on the TCS silane raw material in this process requires the recovery, separation and recycling of these components, which are produced as unreacted TCS, HCL and a significant amount of STC (silane tetrachloride) by-products in the exhaust gas. .

However, in the related art, there is a problem in that expensive resources are wasted by discharging the unreacted expensive silane gas without recovery.

 Kim Hee Young. Manufacture of polysilicon for solar cell. Korean Chem. Eng. Res, Vol. 46, No. 1, February, 2008, pp. 37-49

The present invention has been proposed to solve the above problems, and a main object of the present invention is a silane recovery apparatus which can efficiently recover and recycle expensive silane gas, which is a by-product generated in the manufacturing process of polysilicon. To provide.

Another object of the present invention is to provide a silane recovery method using the silane recovery apparatus.

A silane recovery device for recovering silane gas, which is a by-product generated in the process of manufacturing polysilicon, in a liquid state, comprising: a closed housing, a gas inlet provided in a lower portion of the housing, and installed in the lower side of the housing; Cooling space for dropping the temperature of the silane gas passing through the primary cyclone droplet unit by the cooling means is installed on the primary cyclone droplet unit for droplets of the silane gas flowing through the inlet, the primary cyclone droplet unit The secondary droplet unit is mounted on the upper portion of the cooling space part and droplets the silane gas passing through the cooling space part, and is vertically mounted at a predetermined interval on the upper portion of the secondary droplet unit. Filtration filter for filtering and agglomerating the fine silane droplets passed through, provided in the upper portion of the housing, passing through the filter filter to remove the silane A silane liquid condensed and recovered in the primary cyclone droplet unit, the cooling space unit, the secondary droplet unit, and the filtration filter, provided at an inner lower portion of the gas discharge unit for discharging gas and the primary cyclone droplet unit; Provided is a silane recovery apparatus including a silane liquid collecting unit for collecting.

In addition, the cooling means is a laminate circulation pipe which is installed in a coil shape on the lower inner peripheral surface of the housing to circulate the refrigerant supplied by the refrigerant supply unit.

In addition, the cooling means is mounted on the lower inner circumferential surface of the housing and is composed of a heat exchanger provided with a valve for introducing and discharging the cooling medium.

In addition, the silane recovery apparatus, characterized in that the primary cyclone droplet unit is a conical tube that gradually decreases from the top to the lower diameter from the top.

In addition, the silane recovery apparatus, characterized in that the housing has a conical shape that the outer diameter gradually decreases downward.

In addition, an object of the present invention is the first droplet step to drop the silane gas flowing into the interior of the housing, the cooling step of cooling the silane gas passed through the primary droplet step, the secondary to drop the silane gas passed through the cooling step Filtration step of filtering and condensing the silane droplets passed through the droplet step and the secondary droplet step, and collecting step of collecting the silane solution condensed and recovered in the primary droplet step, the cooling step, the secondary droplet step, and the filtration step. To provide.

In addition, the filtration step is a silane recovery method characterized in that the silane gas having undergone the second droplet step is filtered by a filter having a micropore droplets.

The silane recovery apparatus and recovery method according to the present invention recover liquid silane through a process such as a first droplet stage, a cooling stage, a secondary droplet stage, and the like, without releasing silane gas, a by-product generated in the process of manufacturing polysilicon. It has an excellent effect of increasing economic efficiency by recycling.

In addition, the present invention exhibits an excellent effect of maximizing the droplet effect by the cyclone effect of the silane gas introduced therein by configuring the primary cyclone droplet unit and the silane liquid collecting unit in a conical shape.

1 is a longitudinal sectional view showing a silane recovery apparatus according to a first embodiment of the present invention.
2 is a cross-sectional view of FIG. 1
3 is a longitudinal sectional view showing a silane recovery apparatus according to a second embodiment of the present invention.
Figure 4 is a flow chart showing a silane recovery method according to the present invention.

Hereinafter, preferred embodiments of the present invention and physical properties of the respective components will be described in detail with reference to the accompanying drawings. However, the present invention is not limited thereto, And this does not mean that the technical idea and scope of the present invention are limited.

1 is a longitudinal cross-sectional view of a silane recovery apparatus according to a first embodiment of the present invention, and a gas inlet 20 through which silane gas is introduced is provided at a lower side of the housing 10, and the interior of the housing 10 is provided. The lower side is provided with a primary cyclone droplet unit 30 for dropletizing the silane gas flowing through the gas inlet 20, the gas inlet 20 in the lower inner peripheral surface of the housing 10 Refrigerant gas supplied by the refrigerant supply unit 210 using the principle of the refrigeration cycle as the cooling space portion 40 for lowering the silane gas temperature of 15 to 20 ℃ flowing through the zero to 0 ℃ or less circulation Silane circulating pipe 120 is installed to be stacked and wrapped in a coil shape, the silane flowing through the gas inlet 20 to the upper portion of the refrigerant circulation pipe 120 inside the housing 10 through the cooling space portion Secondary droplets that vaporize gas The units 50 are provided.

Here, the primary cyclone droplet unit 30 may be configured as a conical tube whose outer diameter is gradually shafted toward the lower side. In addition, the secondary droplet unit 50 may be applied in the form of a demister (mesh).

In addition, a filter support 61 is installed at an upper portion of the secondary droplet unit 50 provided in the housing 10, and the filter support 61 is not agglomerated in the secondary droplet unit 50. A plurality of filtration filters 60 for re-aggregating the fine silane droplets are vertically mounted at regular intervals, and the gas having the silane component removed therethrough is passed through the filtration filter 60 at an upper portion of the housing 10. A gas discharge unit 70 for discharging is provided.

In addition, the lower portion of the housing 10 is provided with a silane liquid collecting unit 80 for collecting the silane liquid containing the silane collected in the housing. At this time, the housing 10 is formed in a conical shape that the outer diameter gradually decreases downward.

Therefore, the first cyclone droplet unit 30 and the lower portion of the housing 10 are conical in shape, so that the silane gas introduced therebetween vortex due to the cyclone effect to maximize the droplet effect of the silane gas. have.

In addition, the upper portion of the housing 10 may be installed to open and close the sealing lid 11 for sealing the inside of the housing.

As shown in FIG. 1, when the silane gas is introduced through the gas inlet 20 at the lower side of the housing 10, the present invention configured as described above has a conical primary cyclone droplet unit 30 and a housing 10. Vortex occurs as it is guided between the lower parts. More specifically, the gas introduced into the mist (MIST) is over the inner wall of the housing 10 while hitting the outer wall of the cone-shaped primary cyclone droplet unit 30, the gas introduced into the housing 10 is the primary cyclone droplet The cyclone droplet unit 30 having a conical shape at the bottom of the unit 30 and the housing descends to the bottom of the cyclone droplet unit 30, causing a tornado and rising to the cooling space 40 through the center of the conical shape. At this time, the cyclone descends to the lower end of the conical shape of the primary cyclone droplet unit 30 and the housing 10, and the speed increases, and the centrifugal force is relatively large among the condensate of the silane gas and the droplet component in the mist state by the centrifugal force. As the condensate, which is a particle, strikes the inner wall of the housing, primary dropletization is performed, and the silane liquid having primary dropletization is collected in the silane collecting unit 80 and discharged to the outside through the discharge pipe 90.

Subsequently, the silane gas of 15 to 20 ° C. in the mist state not dropleted while passing through the primary cyclone droplet unit is excessively exceeded in the cooling space 40 of the present invention. In this case, the cooling space 40 is supplied by the refrigerant supply unit 210 into the refrigerant circulation pipe 120 installed to be laminated and wrapped in a coil shape on the lower inner circumferential surface of the housing 10 that is the cooling means 100. As the refrigerant gas of -20 ° C or less is circulated, the temperature of silane gas of 15 to 20 ° C flowing through the silane gas inlet 20 is lowered to 0 ° C or less, wherein the silane gas is saturated due to the temperature drop. In this state, the silane gas condenses in the cooling space part 40. Some of the silane liquid condensed in the cooling space 40 and proceeded with the droplets are condensed in the cooling space 40 or the refrigerant circulation pipe 120 to fall into the silane liquid collecting unit 80 or the temperature is lowered. As the gas rises through the cooling space 40 and passes through the secondary droplet unit 50 installed at the upper portion of the refrigerant circulation pipe 120, secondary dropletization proceeds at the lower end of the secondary dropletization unit. At this time, the secondary droplet unit 50 may be applied to the demister (Demister) of the network form. The silane solution aggregated in the secondary droplet unit 50 is dropped into the silane solution collecting unit 80.

In addition, the plurality of filtration filters 60 mounted on the filter support 61 on the upper portion of the secondary droplet unit 50 have fine particles remaining without droplet formation even though silane gas passes through the secondary droplet unit 50. The silane droplets are filtered through a filter having micropores, and at the same time, the fine droplets are aggregated to form final droplets and only the exhaust gas from which the silane is removed is discharged to the outside. While passing through the filtration filter 60, fine silane liquid droplets aggregate at the bottom of the filtration filter 60 to form droplets, and in the upper portion of the filtration filter 60, the gas from which the silane component is removed is discharged from the other side of the upper portion of the housing 10. The silane solution discharged through the unit 70 and condensed in the inside of the housing 10 is collected downward into the silane solution collecting unit 80 at the lower end of the housing 10 while being discharged downward. It is discharged to the outside through the process of recovering the silane to the liquid phase is repeated.

That is, the technical features of the present invention are economical because it is possible to recycle expensive silane because the silane contained in the silane gas is collected by the primary cyclone droplet unit 30 and the secondary droplet unit 50. In particular, the silane gas flowing between the primary cyclone droplet unit 30 and the conical shape at the bottom of the housing 10 can be disturbed by the cyclone effect to increase the collection efficiency of the silane liquid and the primary cyclone droplet unit 30. By forming a cooling space between the secondary droplet unit 50 and the silane gas to saturate to form a condensation through the secondary droplet unit 50 to collect the maximum silane liquid. In addition, the fine silane droplets contained in the silane gas passing through the secondary droplet unit 50 are filtered through the micropores of the filtration filter 60 while passing through the filtration filter 60 of the present invention to proceed with the droplets again. There is a characteristic that can maximize the collection recovery rate of the silane solution.

In addition, as shown in FIG. 2 as a second embodiment of the present invention, the cooling means 200 is a valve for introducing and discharging a cooling medium such as refrigerant gas into the cooling unit on the lower inner peripheral surface of the housing 10 ( Even if the heat exchanger 210 provided with the 211) 212 is mounted and used, the same role as that of the present invention can be achieved.

In addition, the medium used for the said cooling means 100 and 200 of this invention is not limited to refrigerant gas, In addition, water, compressed air, etc. can be arbitrarily selected and used.

Figure 3 is a flow chart showing a silane recovery method according to the present invention, the silane recovery method according to the present invention is the first droplet step (S10) to drop the silane gas flowing into the interior of the housing, the silane that passed through the first droplet step Cooling step (S20) for cooling the gas, the secondary droplet step (S30) to drop the silane gas after the cooling step, the filtration step (S40) and agglomerated and filtered the silane droplets passed through the secondary droplet step (S40) and the 1 It consists of a collecting step (S50) for collecting the silane solution condensed and recovered in the secondary droplet step, the cooling step, the secondary droplet step, the filtration step.

The first droplet step (S10) is to drop the silane gas flowing into the inside of the housing, the gas introduced in the mist (MIST) state of the primary cyclone droplet unit 30 and the primary cyclone droplet unit (conical) ( As in 30, the lower end portion is excessively over the lower end of the housing 10 having a conical shape, wherein the gas introduced into the housing 10 hits the outer wall of the primary cyclone droplet unit 30 and descends to the lower end and at the same time as the primary As the cyclone droplet unit 30 rotates the inner wall of the lower end of the housing 10 having the same cone shape, a tornado is caused to rise to the cooling space 40 through the center of the cone shape of the primary droplet unit 30. At this time, the cyclone descends to the lower end of the conical shape of the primary cyclone droplet unit 30 and the housing 10, and the speed increases, and is relatively among condensed bodies of silane gas and water droplets in a mist (MIST) state by centrifugal force. Primary dropletization proceeds as a large number of aggregates, which are large particles, strike the inner wall of the housing 30 by centrifugal force.

The cooling step (S20) is a step of cooling the silane gas having passed through the first droplet step (S10), wherein the silane gas that has not been dropleted in the first droplet step having passed through the first droplet step (S10) has a conical shape. As a process of entering the center of the secondary cyclone droplet unit 30 and passing through the cooling space part 40, the silane gas introduced at 15 to 20 ° C. is provided by the refrigerant supply part 210 provided in the cooling space part 40. When passing through a refrigerant of -20 ℃ or less is cooled to 0 ℃ or less, at this time, the cooled silane gas is saturated due to the temperature drop and condensation proceeds. Mist condensed through this process may proceed with the droplets of silane gas on the surface of the cooling space 40 or the circulation pipe 120, and the silane solution dropped through the process drops the silane solution collection unit ( 80).

The secondary droplet step (S30) is a step of maximizing the silane gas passed through the cooling step (S20) to the maximum, the silane gas whose temperature has passed through the cooling step (S20) is condensation proceeds at the same time The second droplet unit 50 passes through a plurality of network-type demisters, and the condensed silane gas proceeds from the lower end of the demister provided in the secondary droplet unit 50.

The filtration step (S40) is a step of final agglomeration and filtering of the fine silane droplets in the silane gas not dropleted even though the second droplet step (S30), the secondary droplet step (S30) through the micropores of the filter In step 1), the fine silane droplets contained in the silane gas passing through the demister are filtered and aggregated once more to form droplets.

At this time, depending on the size of the fine droplets contained in the silane gas, the size of the micropores of the filtration filter 60 may be selected by selecting the size of 1 μm to 10 μm, and the droplets may proceed, At the same time, the gas from which the silane is removed is discharged to the gas outlet 70 at the top of the filtration filter.

The collecting step (S50) is a step of collecting the silane solution condensed and recovered in the first droplet step (S10), the cooling step (S20), the secondary droplet step (S30), the filtration step (S40), The silane solution is made through the collecting unit 80.

10 housing 11: sealing lid
20: gas inlet 30: 1 droplet unit
40: cooling space 50: secondary droplet unit
60 filter 61 filter support
70 gas discharge unit 80 silane liquid collecting unit
90: discharge pipe 100, 200: cooling means
110: refrigerant supply unit 120: circulation pipe
210: heat exchanger 211, 212: valve

Claims (7)

As a silane recovery device for recovering silane gas, a by-product generated in the manufacturing process of polysilicon, in a liquid state,
Closed housing;
A gas inlet provided in a lower portion of the housing;
A first cyclone droplet unit installed at an inner lower side of the housing to droplet silane gas introduced through the gas inlet;
A cooling space unit installed at an upper portion of the primary cyclone droplet unit to lower the temperature of the silane gas passing through the primary cyclone droplet unit by a cooling unit;
A secondary droplet unit mounted on an upper portion of the cooling space part to droplet silane gas passing through the cooling space part;
A filtration filter mounted vertically at a predetermined interval on an upper portion of the secondary droplet unit to filter and aggregate the fine silane droplets passing through the secondary droplet unit;
A gas discharge part provided at an upper portion of the housing to discharge gas from which silane has been removed through the filtration filter; And
A silane solution collecting part provided at an inner lower portion of the primary cyclone droplet unit and collecting the silane solution condensed and recovered by the primary cyclone droplet unit, the cooling space unit, the secondary droplet unit, and the filtration filter; Silane recovery unit.
The method of claim 1,
The cooling means is a silane recovery apparatus, characterized in that the refrigerant circulation pipe is installed on the lower inner circumferential surface of the housing in a coil shape to circulate the refrigerant supplied by the refrigerant supply unit.
The method of claim 1,
The cooling means is a silane recovery device characterized in that the heat exchanger is mounted on the lower inner peripheral surface of the housing and installed with a valve for introducing and discharging the cooling medium.
The method of claim 1,
The first cyclone droplet unit is a silane recovery device, characterized in that the conical tube is gradually reduced in diameter from the top toward the bottom downward.
The method of claim 1,
The housing is a silane recovery apparatus characterized in that the conical shape of the outer diameter gradually decreases downward.
A first droplet step of dropping silane gas introduced into the housing;
A cooling step of cooling the silane gas having passed through the first droplet step;
A secondary droplet step of dropping the silane gas that has passed through the cooling step;
A filtration step of filtering and agglomerating fine silane droplets having passed through the second droplet stage; And
A collecting step of collecting the silane solution condensed and recovered in the first droplet step, the cooling step, the second droplet step, and the filtration step;
Silane recovery method characterized in that consisting of.
The method according to claim 6,
The filtration step is a silane recovery method characterized in that the silane gas having undergone the secondary droplet step is filtered by a filter having a micropore droplets.

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