Patent Publication Number: US-8974760-B2

Title: Hydrogen chloride gas ejecting nozzle, reaction apparatus for producing trichlorosilane and method for producing trichlorosilane

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of U.S. application Ser. No. 12/289,210, filed Oct. 22, 2008 which claims the right of priority under 35 U.S.C. §119 based on Japanese Patent Application Nos. 2007-277788 and 2008-197072 filed Oct. 25, 2007 and Jul. 30, 2008, respectively. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a hydrogen chrolide gas ejecting nozzle used in a reaction apparatus for producing trichlorosilane when trichlorosilane is generated by reaction of metal silicon powder with hydrogen chloride gas, thereby ejecting the hydrogen chloride gas into the metal silicon powder supplied inside an apparatus main body, a reaction apparatus for producing trichlorosilane equipped with the hydrogen chrolide gas ejecting nozzle, and a method for producing trichlorosilane by using the hydrogen chrolide gas ejecting nozzle. 
     2. Description of Related Art 
     Trichlorosilane (SiHCl 3 ) used as a material for producing extremely high purity silicon having a purity greater than 99.999999999% is produced by reacting metal silicon powder (Si) of about 98% in purity with hydrogen chloride gas (HCl). 
     As a reaction apparatus for producing trichlorosilane in which metal silicon powder is reacted with hydrogen chloride gas to generate trichlorosilane as described above, there has been proposed, for example, an apparatus disclosed in Japanese Unexamined Patent Application, First Publication No. 2002-220219, which is provided with an apparatus main body at which metal silicon powder is supplied and gas introduction device for introducing hydrogen chloride gas into the apparatus main body from the bottom portion of the apparatus main body. In this case, the gas introduction device is provided with hydrogen chrolide gas ejecting nozzles having an ejection hole for ejecting hydrogen chloride gas into metal silicon powder. 
     Metal silicon powder, the grain size of which is relatively small, that is, 1000 μm or smaller, is supplied into an apparatus main body, and hydrogen chloride gas is ejected at a high speed through a hydrogen chrolide gas ejecting nozzle from the bottom portion of the apparatus main body, by which metal silicon powder is fluidized. Thereby, the metal silicon powder is sufficiently contacted with the hydrogen chloride gas to carry out a reaction, thereby obtaining trichlorosilane. 
     Incidentally, conventional hydrogen chrolide gas ejecting nozzles are fixed to a bottom portion of an apparatus main body so that the ejection holes thereof open upward. In this case, since metal silicon powder is small in grain size, as described previously, the powder may enter into ejection holes to result in clogging. Therefore, it is necessary to exchange or clean the hydrogen chrolide gas ejecting nozzle. However, since the hydrogen chrolide gas ejecting nozzle is fixed to the bottom portion of the apparatus main body, the hydrogen chrolide gas ejecting nozzle cannot be easily removed. 
     SUMMARY OF THE INVENTION 
     The present invention has been made in view of the above situation, an object of which is to provide a hydrogen chrolide gas ejecting nozzle capable of suppressing the clogging resulting from metal silicon powder and also improving the production efficiency of trichlorosilane by widely dispersing hydrogen chloride gas, a reaction apparatus for producing trichlorosilane equipped with the hydrogen chrolide gas ejecting nozzle and a method for producing trichlorosilane by using the hydrogen chrolide gas ejecting nozzle. 
     The hydrogen chrolide gas ejecting nozzle of the present invention is a hydrogen chrolide gas ejecting nozzle used in a reaction apparatus for producing trichlorosilane in which metal silicon powder is reacted with hydrogen chloride gas to generate trichlorosilane and provided with a shaft portion extending in a longitudinal direction and a head portion extending in a direction intersecting the longitudinal direction of the shaft portion. A supply hole extending in the longitudinal direction is disposed at the shaft portion. A plurality of ejection holes are formed at the head portion. Each of the ejection holes is communicatively connected to the supply hole and opened on the outer surface of the head portion by extending in a direction intersecting the direction to which the supply hole extends. 
     The hydrogen chrolide gas ejecting nozzle of the present invention is provided with a shaft portion extending in a longitudinal direction and a head portion extending in a direction intersecting the longitudinal direction of the shaft portion. A supply hole disposed at the shaft portion extends in the longitudinal direction of the shaft portion, and ejection holes extending in a direction intersecting the supply hole are disposed at the head portion. Therefore, where the hydrogen chrolide gas ejecting nozzle is attached to the above described reaction apparatus for producing trichlorosilane, metal silicon powder is less likely to enter into the ejection holes, thus making it possible to prevent the ejection holes from being clogged. 
     Further, a plurality of ejection holes are formed, thereby hydrogen chloride gas can be ejected in a plurality of directions, and hydrogen chloride gas can be widely dispersed into metal silicon powder to accelerate the reaction. 
     It is preferable that the hydrogen chrolide gas ejecting nozzle of the present invention is provided at the shaft portion with a thread portion. 
     The hydrogen chrolide gas ejecting nozzle of the present invention is attached removably to the gas introduction devices of the above described reaction apparatus for producing trichlorosilane. Therefore, it can be easily exchanged when deteriorated after prolonged use. Further, if an ejection hole should be clogged, the member can be taken out for cleaning and therefore quite easy in maintenance. Still further, the hydrogen chrolide gas ejecting nozzle is easily attached or detached by screwing. For this reason, the member can be further improved in maintenance. It is preferable that the head portion of the hydrogen chrolide gas ejecting nozzle be formed in such a shape as to engage with industrial tools, for example, a wrench. 
     It is also preferable that the hydrogen chrolide gas ejecting nozzle of the present invention be formed in such a manner that a plurality of the ejection holes extend radially from the supply hole. 
     In the hydrogen chrolide gas ejecting nozzle of the present invention, hydrogen chloride gas supplied through the supply hole is ejected radially from a plurality of ejection holes, thus making it possible to more widely disperse the hydrogen chloride gas into metal silicon powder. 
     The reaction apparatus for producing trichlorosilane of the present invention is a reaction apparatus for producing trichlorosilane in which metal silicon powder is reacted with hydrogen chloride gas to generate trichlorosilane, and provided with an apparatus main body to which the metal silicon powder is supplied and gas introduction means for introducing the hydrogen chloride gas into the apparatus main body from the bottom portion of the apparatus main body. In the gas introduction devices, the hydrogen chrolide gas ejecting nozzle is attached removably through the bottom plate portion of the apparatus main body and the head portion is arranged on the bottom plate portion. 
     According to the reaction apparatus for producing trichlorosilane of the present invention, the hydrogen chrolide gas ejecting nozzle is prevented from being clogged, thereby securing a stable operation. Further, the hydrogen chloride gas is widely dispersed into the metal silicon powder, thus making it possible to improve greatly the production efficiency of trichlorosilane. 
     The method for producing trichlorosilane of the present invention is a method for producing trichlorosilane in which metal silicon powder is reacted with hydrogen chloride gas to generate trichlorosilane. More particularly, the hydrogen chrolide gas ejecting nozzle is attached to the bottom plate portion of the apparatus main body to which the silicon powder is supplied, the head portion is arranged on the upper surface of the bottom plate portion, and hydrogen chloride gas is ejected from the ejection holes of the hydrogen chrolide gas ejecting nozzle, while the metal silicon powder is supplied to a lower part of the apparatus main body. 
     The present invention makes possible the prevention of clogging resulting from metal silicon powder. The present invention also makes possible improvement in the production efficiency of trichlorosilane by widely dispersing hydrogen chloride gas. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side elevational view showing a hydrogen chrolide gas ejecting nozzle, which is an embodiment of the present invention. 
         FIG. 2  is a top view of the hydrogen chrolide gas ejecting nozzle given in  FIG. 1 . 
         FIG. 3  is a cross-sectional view showing a reaction apparatus for producing trichlorosilane using the hydrogen chrolide gas ejecting nozzle given in  FIG. 1 . 
         FIG. 4  is a front view showing a state in which the hydrogen chrolide gas ejecting nozzle given in  FIG. 1  is attached to gas introduction means. 
         FIG. 5  is a perspective view showing a plurality of members for ejecting hydrogen chloride gas arrayed at the bottom plate portion of the apparatus main body. 
         FIG. 6  is a side elevational view of a second embodiment of the hydrogen chrolide gas ejecting nozzle. 
         FIG. 7  is a top view of the hydrogen chrolide gas ejecting nozzle given in  FIG. 6 . 
         FIG. 8  is a side elevational view showing a third embodiment of the hydrogen chrolide gas ejecting nozzle. 
         FIG. 9  is a top view of the hydrogen chrolide gas ejecting nozzle given in  FIG. 8 . 
         FIG. 10  is a side elevational view showing a fourth embodiment of the hydrogen chrolide gas ejecting nozzle. 
         FIG. 11  is a top view of the hydrogen chrolide gas ejecting nozzle given in  FIG. 10 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, an explanation will be made for embodiments of the present invention by referring to the attached drawings. 
     As shown in  FIG. 1  and  FIG. 2 , the hydrogen chrolide gas ejecting nozzle  1  of the present embodiment is provided with a shaft portion  2  formed approximately in a cylindrical shape and a head portion  3  extending in a direction intersecting the longitudinal direction of the shaft portion  2  (the vertical direction in  FIG. 1 ) at the upper end of the shaft portion  2 . 
     In the present embodiment, the head portion  3  extends in a direction orthogonal to the longitudinal direction of the shaft portion  2 , and has a regular hexagonal shape when viewed from the top, as shown in  FIG. 2 . In addition, an upper surface  3 A of the head portion  3  is a plain surface orthogonal to the longitudinal direction of the shaft portion  2 , and a side surface  3 B of the head portion  3  is positioned orthogonal to the upper surface  3 A. Thereby, the head portion  3  is formed approximately in a regular hexagonal column shape. 
     Further, a male thread  2 A is formed on the outer circumferential surface of the shaft portion  2 . Therefore, the hydrogen chrolide gas ejecting nozzle  1  is formed in the same shape as a hexagon head bolt and the head portion  3  is able to engage with industrial tools such as a wrench. 
     The shaft portion  2  is provided with a supply hole  4  which is opened on the lower end surface  2 B thereof and extending along the longitudinal direction of the shaft portion  2 . In addition, the supply hole  4  is not opened on the upper surface  3 A of the head portion  3  but formed as a blind hole. 
     Then, the head portion  3  is provided with a plurality of ejection holes  5  communicatively connected to the supply hole  4  and extending in a direction intersecting a direction at which the supply hole  4  extends. In the present embodiment, as shown in  FIG. 1  and  FIG. 2 , six ejection holes  5  are formed so as to be respectively orthogonal to the direction at which the supply hole  4  extends. These six ejection holes  5  are, as shown in  FIG. 2 , formed so as to extend radially from the supply hole  4  located at the center of the head portion  3  and respectively opened on the side surfaces of the head portion  3  formed in a regular hexagonal column shape. In other words, an opening portion of the ejection hole  5  faces in a direction orthogonal to the longitudinal direction of the shaft portion  2 . 
     Next, an explanation will be made for a reaction apparatus for producing trichlorosilane  10  in which the hydrogen chrolide gas ejecting nozzle  1  of the present embodiment is used. 
     As shown in  FIG. 3 , the reaction apparatus for producing trichlorosilane  10  has an apparatus main body comprising a body portion  12  having an approximately cylindrical shape and a bottom plate portion  13  and a ceiling  14  respectively sealing the lower and top ends of the body portion  12 . In this case, as shown in  FIG. 3  and  FIG. 4 , an upper surface  13 A and a lower surface  13 B of the bottom plate portion  13  are arranged so as to be orthogonal to the axis line of the cylinder formed by the body portion  12 . 
     A silicon powder supply port  15  for supplying metal silicon powder into the apparatus main body  11  is formed at a lower part of the body portion  12  of the apparatus main body  11 . An introduction piping  30  for carrier gas is connected to the silicon powder supply port  15 , metal silicon powder is supplied from a feed hopper  31  through a valve  32  to the introduction piping  30  for carrier gas and then supplied through the silicon powder supply port  15  into the apparatus main body  11 . Further, a cyclone separator  33  to be described later is connected to the feed hopper  31 , and a silicon powder supply system  40  for supplying the metal silicon powder from the outside is also connected to the feed hopper  31 . 
     A gas removal port  17  is disposed at the center of the ceiling  14  of the apparatus main body  11  for removing trichlorosilane gas generated by reaction. 
     Gas introduction unit  20  is installed below the apparatus main body  11  for introducing hydrogen chloride gas into the apparatus main body  11 . 
     The gas introduction unit  20  is provided with a gas chamber  21  for pooling hydrogen chloride gas and gas supply ports  22  for supplying the hydrogen chloride gas into the gas chamber  21 . In this case, the gas chamber  21  is partitioned from the interior of the apparatus main body  11  by the bottom plate portion  13  of the apparatus main body  11 . 
     Then, as shown in  FIG. 4 , the hydrogen chrolide gas ejecting nozzle  1  of the present embodiment is placed at the bottom plate portion  13  of the apparatus main body  11 . More specifically, an attachment hole  13 C is formed at the bottom plate portion  13  of the apparatus main body  11 , and the shaft portion  2  of the hydrogen chrolide gas ejecting nozzle  1  is inserted into the attachment hole  13 C. Then, the head portion  3  of the hydrogen chrolide gas ejecting nozzle  1  is placed on the upper surface  13 A of the bottom plate portion  13 . Two nuts  25  are screwed onto a male thread portion  2 A formed at the shaft portion  2  from the side of the lower surface  13 B of the bottom plate portion  13 , and the bottom plate portion  13  is held between the nuts  25  and the head portion  3 . In addition, a washer  26  is placed between the head portion  3  and the upper surface  13 A of the bottom plate portion  13  and another washer  26  is placed between the nut  25  and the lower surface  13 B of the bottom plate portion  13 . 
     Thereby, the shaft portion  2  of the hydrogen chrolide gas ejecting nozzle  1  is inserted through the bottom plate portion  13  into the gas chamber  21  and attached removably to the bottom plate portion  13 . Further, an equalizing pipe  27  is communicatively connected to the supply hole  4  of the shaft portion  2 . 
     As described above, the hydrogen chrolide gas ejecting nozzle  1  of the present embodiment is fixed to the bottom plate portion  13  of the apparatus main body  11  and arranged so that the shaft portion  2  extends from the bottom plate portion  13  downwardly (along the axis line of a cylinder formed by the body portion  12  of the apparatus main body  11 ) and also the upper surface  3 A of the head portion  3  is parallel with the lower surface  13 B of the bottom plate portion  13  of the apparatus main body  11 . Further, the supply hole  4  of the shaft portion  2  is arranged so that the lower end thereof is opened inside the gas chamber  21 , while the ejection holes  5  of the head portion  3  are arranged so as to be opened in a direction orthogonal to the axis line of a cylinder formed by the body portion  12  of the apparatus main body  11 . Then, hydrogen chloride gas supplied from the gas supply port  22  into the gas chamber  21  is ejected through the supply hole  4  of the hydrogen chrolide gas ejecting nozzle  1  from the ejection holes  5  into the apparatus main body  11 . The gas introduction unit  20  is provided with a gas supply port  22 , a gas chamber  21  and a hydrogen chrolide gas ejecting nozzle  1 . 
     In the present embodiment, as shown in  FIG. 5 , a plurality of hydrogen chloride ejecting nozzles  1  are arrayed in a hound&#39;s tooth configuration on whole the upper surface  13 A of the bottom plate portion  13 . 
     Next, an explanation will be made for a method for producing trichlorosilane by using the reaction apparatus for producing trichlorosilane  10 . 
     Metal silicon powder is supplied from a silicon powder supply system  40  to the feed hopper  31 , introduced into the introduction piping  30  for carrier gas from the feed hopper  31  through a valve  32  and supplied into the apparatus main body  11  through the silicon powder supply port  15  by gas flow transportation. In this case, hydrogen chloride gas is used as a carrier gas for gas flow transportation. The carrier gas is preferably introduced at a constant pressure. 
     Further, the gas introduction unit  20  is used to introduce hydrogen chloride gas into the apparatus main body  11 . The hydrogen chloride gas is ejected to the apparatus main body  11  through a plurality of the members for ejecting hydrogen chloride gas  1  arranged at the bottom plate portion  13  of the apparatus main body  11 . The hydrogen chloride gas ejected from the members for ejecting hydrogen chloride gas  1  is introduced into metal silicon powder. 
     As described above, hydrogen chloride gas is ejected to metal silicon powder inside the apparatus main body  11 , by which the metal silicon powder is fluidized inside the apparatus main body  11 . The metal silicon powder makes contact with the hydrogen chloride gas, while being fluidized, by which the metal silicon powder is reacted with the hydrogen chloride gas at a predetermined temperature, to generate trichlorosilane gas. 
     The thus generated trichlorosilane gas is removed from a gas removal port  17  installed on a ceiling  14  of the apparatus main body  11  and supplied to subsequent steps. Further, unreacted metal silicon powder inside the apparatus main body  11  is discharged together with trichlorosilane gas from the gas removal port  17 , collected by the cyclone separator  33  at a subsequent step, supplied to the feed hopper  31 , introduced into the introduction piping  30  for carrier gas, and supplied again into the apparatus main body  11 . The metal silicon powder not collected by the cyclone separator  33  is removed through a filter  34  at a subsequent step. 
     The hydrogen chrolide gas ejecting nozzle  1  of the present embodiment is provided with a shaft portion  2  formed approximately in a cylindrical shape and a head portion  3  extending in a direction intersecting the longitudinal direction of the shaft portion  2  (the vertical direction in  FIG. 1 ). The shaft portion  2  is arranged so as to extend in a vertical direction of the apparatus main body  11 , and the supply hole  4  disposed at the shaft portion  2  is also arranged so as to face the vertical direction of the apparatus main body  11  (the axial direction of a cylinder formed by the body portion  12  of the apparatus main body  11 ). Then, an opening portion of the ejection hole  5  orthogonal to the supply hole  4  is opened on a side surface of the head portion  3 , by which there is no chance that the opening portion of the ejection hole  5  faces upward. As a result, metal silicon powder is less likely to enter into the ejection holes  5 , thus making it possible to prevent the ejection holes  5  from being clogged. 
     Since a plurality of the ejection holes  5  are formed so as to extend radially from the supply hole  4 , it is possible to eject hydrogen chloride gas from one hydrogen chrolide gas ejecting nozzle  1  toward a plurality of directions and also accelerate the reaction by widely dispersing hydrogen chloride gas into metal silicon powder. Thereby, the reaction of the metal silicon powder with the hydrogen chloride gas can be further accelerated to improve the production efficiency of trichlorosilane. 
     Further, since the hydrogen chrolide gas ejecting nozzle  1  is attached removably to the bottom plate portion  13  of the apparatus main body  11 , it can be easily exchanged after deterioration due to prolonged use. If the ejection holes  5  become clogged, the member can be cleaned in a state of being removed from the bottom plate portion  13  of the apparatus main body  11 . Therefore, it is quite easy in maintenance. Still further, since the head portion  3  of the hydrogen chrolide gas ejecting nozzle  1  is formed in a regular hexagonal column shape, it can be screwed by being engaged with industrial tools such as a wrench and easily attached or detached. 
     The hydrogen chrolide gas ejecting nozzle  1  of the present embodiment is formed in the same shape as a hexagonal bolt. Therefore, a hexagonal bolt for general use can be bored to produce the hydrogen chrolide gas ejecting nozzle  1 , thus making it possible to produce the hydrogen chrolide gas ejecting nozzle  1  at a lower cost. 
     Further, in the present embodiment, an equalizing pipe  27  communicatively connected to the supply hole  4  is connected to the shaft portion  2  of the hydrogen chrolide gas ejecting nozzle  1 , thus making it possible to equalize a pressure of hydrogen chloride gas ejected from the ejection holes  5 . 
     An explanation has been made so far for the hydrogen chrolide gas ejecting nozzle of an embodiment of the present invention. However, the present invention shall not be limited thereto and may be modified in any way within a scope not departing from the technical idea of the invention. 
     For example, in the present embodiment, an explanation has been made for a case where the ejection holes are formed so as to be orthogonal to a direction at which the supply hole extends. However, the present embodiment shall not be limited thereto but may include the case where the ejection holes intersect the supply hole so that the opening portion will not face upward when attached to the bottom plate portion of the apparatus main body. 
     An explanation has also been made for the case where six ejection holes are formed in a hexagonal bolt shape. There is no restriction on the number of the ejection holes. It is preferable to make an appropriate design, with consideration given to the arrangement of the members for ejecting hydrogen chloride gas and the shape of the apparatus main body. 
       FIG. 6  to  FIG. 11  show embodiments of the hydrogen chrolide gas ejecting nozzle. Any one of the embodiments is different in shape of the head portion from a first embodiment but similar in the shaft portion to the first embodiment. Therefore, the same symbols or numerals are given to the shaft portion, an explanation of which is omitted here. Also, the same symbols or numerals are given to other components similar to those of the first embodiment such as the supply hole and the ejection hole. The head portion  52  of the hydrogen chrolide gas ejecting nozzle  51  shown in  FIG. 6  and  FIG. 7  is fanned in a square shape, when viewed from the top, on a plain surface where the upper surface  52 A is orthogonal to a length direction, and four ejection holes  5  orthogonal to the supply hole  4  are respectively opened on each of side surfaces  52 B of the head portion  52 . The head portion  54  of the hydrogen chrolide gas ejecting nozzle  53  shown in  FIG. 8  and  FIG. 9  is formed in such a shape that both circular ends when viewed from the top are mutually cut in parallel, and an upper surface  54 A is formed on a plain surface orthogonal to the length direction. A pair of circular-arc side surfaces  54 B and a pair of planar side surfaces  54 C are respectively formed on the side surfaces. Further, four ejection holes  5  orthogonal to the supply hole  4  are respectively opened on the circular-arc side surfaces  54 B of the head portion  54 . Still further, the hydrogen chrolide gas ejecting nozzle  55  shown in  FIG. 10  and  FIG. 11  is formed in such a manner that the head portion  56  thereof is formed in a semi-sphere shape and the both ends are partially cut parallel with each other. Therefore, the upper surface  56 A of the head portion  56  is formed in a semi-sphere shape, and a pair of planar side surfaces  56 B are formed parallel with the length direction. Then, four ejection holes  5  intersecting obliquely the supply hole  4  are opened obliquely upward on the semi-sphere upper surface  56 A. 
     Any one of the members for ejecting hydrogen chloride gas having a plain surface portion of the head portion (each of the side surfaces  52 B in  FIG. 6  and  FIG. 7 , planar side surfaces  54 C in  FIG. 8  and  FIG. 9 , planar side surfaces  56 B in  FIG. 10  and  FIG. 11 ) can be attached to or detached from the bottom plate portion by screwing, while engaging tools such as a wrench. 
     Further the head portion of the hydrogen chrolide gas ejecting nozzle may be formed in a triangular shape, etc., when viewed from the top, in addition to the shapes so far described, as long as such a plain surface is formed so that a tool can be engaged with the side surface. 
     While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as being limited by the foregoing description, and is only limited by the scope of the appended claims.