Patent Publication Number: US-8529251-B2

Title: Rotary kiln and product

Description:
INCORPORATION BY REFERENCE 
     The disclosure of Japanese Patent Application No. 2009-212478 filed on Sep. 14, 2009 including the specification, drawings and abstract is incorporated herein by reference in its entirety. The disclosure of Japanese Patent Application No. 2010-127748 filed on Jun. 3, 2010 including the specification, drawings and abstract is incorporated herein by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a rotary kiln that performs a heat treatment on a process material while transferring the process material in an axial direction, and to a product manufactured by the rotary kiln. 
     2. Description of the Related Art 
     A rotary kiln includes a shell that rotates about its own axis (see Japanese Patent Application Publication No. 2008-128492 (JP-A-2008-128492), for example).  FIG. 14  is a perspective view of a rotary kiln disclosed in JP-A-2008-128492. As shown in  FIG. 14 , a rotary kiln  100  includes a shell  101 , a heating section  102 , and a platform  103 . A pair of front and rear rollers  103   a  is disposed on the left side of the upper surface of the platform  103 . Also, a pair of front and rear rollers  103   b  is disposed on the right side of the upper surface of the platform  103 . A pair of left and right tires  101   a  and  101   b  is disposed on the outer peripheral surface of the shell  101 . A gear  101   c  is disposed on the right side of the tire  101   b . The heating section  102  covers the body portion of the shell  101 . 
     The tire  101   a  is placed on the pair of rollers  103   a . Also, the tire  101   b  is placed on the pair of rollers  103   b . When a rotational force is applied to the gear  101   c , the tire  101   a  rolls on the pair of rollers  103   a . Also, the tire  101   b  rolls on the pair of rollers  103   b . This allows the shell  101  to rotate about its own axis. 
     A process material is transferred inside the rotating shell  101  from the right side (supply side) to the left side (discharge side). At this time, the process material is heated by heat of the heating section  102 . In this way, the rotary kiln  100  performs a heat treatment on the process material. 
     In the case of the rotary kiln  100  according to the related art, it is necessary to mount the tires  101   a  and  101   b  on the outer peripheral surface of the shell  101  in order to allow rotation of the shell  101  while securely supporting a rotation axis thereof. In addition, it is necessary to mount the gear  101   c  on the outer peripheral surface of the shell  101  in order to transmit a rotational force. 
     Depending on the material of the shell  101 , however, it may be difficult to mount these members on the outer peripheral surface of the shell  101 . For example, in the case where the shell  101  is made of a ceramic and the tires  101   a  and  101   b  and the gear  101   c  are made of a metal, it is necessary to mount the members on the outer peripheral surface of the shell  101  by tightening the members on the shell  101 . In this case, if the tightening force is loose, the members may slip with respect to the shell  101 . On the contrary, if the tightening force is large, the force that compresses the shell  101  from the radially outer side to the radially inner side may be strong. Thus, it may be difficult to mount the tires  101   a  and  101   b  and the gear  101   c  depending on the material of the shell  101 . Thus, the rotary kiln according to the related art has low versatility for the material of the shell. 
     The shell  101  is designed to have a diameter set in accordance with the amount of production and the characteristics of the process material. For example, in the case where the amount of production of the process material is set to be much, the shell  101  is designed to have a large diameter. On the contrary, in the case where the amount of production of the process material is set to be little, the shell  101  is designed to have a small diameter. 
     In the case of the rotary kiln  100  according to the related art, however, a change in diameter of the shell  101  involves a change in dimensions of the tires  101   a  and  101   b , the gear  101   c , the rollers  103   a  and  103   b , and so forth. For example, an increase in diameter of the shell  101  involves an increase in diameter of the tires  101   a  and  101   b  and the gear  101   c . An increase in diameter of the shell  101  also involves an increase in interval between the pair of rollers  103   a  and interval between the pair of rollers  103   b . On the contrary, a decrease in diameter of the shell  101  involves a decrease in diameter of the tires  101   a  and  101   b  and the gear  101   c . A decrease in diameter of the shell  101  also involves a decrease in interval between the pair of rollers  103   a  and interval between the pair of rollers  103   b . Thus, the rotary kiln  100  according to the related art has low versatility for the diameter of the shell  101 . 
     SUMMARY OF THE INVENTION 
     The rotary kiln according to the present invention has been completed in view of the aforementioned issues. It is an object of the present invention to provide a rotary kiln with high versatility for the material and the diameter of a shell. It is another object of the present invention to provide a product manufactured by the rotary kiln. 
     (1) In order to address the aforementioned issues, a first aspect of the present invention provides a rotary kiln including: a cylindrical shell that includes a supply-side end portion and a discharge-side end portion at both ends in an axial direction of the shell, and a heat treatment chamber which is defined inside the shell and in which a heat treatment is performed on a process material; a supply-side holder that holds the supply-side end portion; a discharge-side holder that holds the discharge-side end portion; a supply-side rotary shaft that allows rotation of the supply-side holder; and a discharge-side rotary shaft that allows rotation of the discharge-side holder, in which the shell is rotated about an axis thereof by rotating at least one of the supply-side rotary shaft and the discharge-side rotary shaft. 
     According to the rotary kiln of the present invention, the supply-side rotary shaft and the discharge-side rotary shaft allow rotation of the shell while securely supporting a rotation axis thereof. A rotational force is transmitted to the shell from at least one of the supply-side rotary shaft and the discharge-side rotary shaft. Therefore, it is not necessary to dispose a member that allows rotation of the shell while securely supporting the rotation axis thereof (for example, the tires  101   a ,  101   b  in  FIG. 14 ) or a member that transmits a rotational force (for example, the gear  101   c  in  FIG. 14 ) on the outer peripheral surface of the shell. Thus, the shell can be rotated with the rotation axis thereof being securely supported regardless of the material of the shell. In addition, a rotational force can be transmitted to the shell regardless of the material of the shell. Thus, the rotary kiln according to the present invention provides high versatility for the material of the shell. 
     Also, according to the rotary kiln of the present invention, it is only necessary to change the supply-side holder and the discharge-side holder in order to change the diameter of the shell. That is, it is not necessary to change the supply-side rotary shaft and the discharge-side rotary shaft. Therefore, the rotary kiln according to the present invention provides high versatility for the diameter of the shell. 
     (2) According to a second aspect of the present invention, in the aforementioned configuration (1), it is preferable that the supply-side holder and the discharge-side holder are attached to the shell so as to be removable in the axial direction. According to this configuration, the shell can be removed from the supply-side holder and the discharge-side holder. This is convenient for inspection, repair, replacement, and so forth of the shell. 
     (3) According to a third aspect of the present invention, in the aforementioned configuration (2), it is preferable that the rotary kiln further includes: a supply-side support cart that includes the supply-side holder, the supply-side rotary shaft, and a bearing portion which rotatably supports the supply-side rotary shaft, and that is movable in the axial direction; and a discharge-side support cart that includes the discharge-side holder, the discharge-side rotary shaft, and a bearing portion which rotatably supports the discharge-side rotary shaft, and that is movable in the axial direction. 
     According to this configuration, the supply-side holder and the supply-side rotary shaft are disposed on the supply-side support cart. Also, the discharge-side holder and the discharge-side rotary shaft are disposed on the discharge-side support cart. Therefore, the supply-side holder and the discharge-side holder are easily movable. That is, the supply-side holder and the discharge-side holder can be easily attached to and removed from the shell. 
     (4) According to a fourth aspect of the present invention, in the aforementioned configuration (3), it is preferable that the supply-side rotary shaft is inserted into the shell from the supply-side end portion, and the rotary kiln further includes a supply part cart that includes a supply section inserted into the supply-side rotary shaft to supply the process material into the heat treatment chamber, and that is movable in the axial direction. 
     According to this configuration, the process material can be easily supplied into the shell. Moreover, the starting point of the heat treatment chamber can be located in the vicinity of the supply-side end portion. That is, the overall length of the heat treatment chamber in the axial direction can be set to be long. Also, according to this configuration, the supply section is disposed on the supply part cart. Therefore, the supply section is easily movable. That is, the supply section can be easily inserted into and taken out of the supply-side rotary shaft. This is convenient for inspection, repair, replacement, and so forth of the supply section. 
     (5) According to a fifth aspect of the present invention, in any one of the aforementioned configurations (2) to (4), it is preferable that the rotary kiln further includes a heating section that includes a heating chamber which is defined inside the heating section and through which the shell penetrates, and that is dividable along the shell. 
     This configuration provides a so-called externally heated rotary kiln. According to this configuration, a portion of the shell that is housed in the heating section can be exposed easily. This is convenient for inspection, repair, replacement, and so forth of the shell. This also allows access to the shell from a radial direction during replacement of the shell. This facilitates replacement work. 
     (5-1) In the aforementioned configuration (5), it is preferable that the heating section includes a lower divided portion and an upper divided portion that can be opened and closed to the lower divided portion, and a lower half portion and an upper half portion of the shell are respectively housed in the lower divided portion and the upper divided portion. 
     According to this configuration, the upper half portion of the shell is exposed by opening the upper divided portion. This is convenient for inspection, repair, replacement, and so forth of the shell. This also allows access to the shell from above during replacement of the shell. This facilitates replacement work. 
     (6) According to a sixth aspect of the present invention, in any one of the aforementioned configurations (1) to (5), it is preferable that the shell includes a supply-side heat insulation portion disposed radially inward of the supply-side end portion and a discharge-side heat insulation portion disposed radially inward of the discharge-side end portion. 
     According to this configuration, heat of the heat treatment chamber is not easily transmitted to the supply-side rotary shaft and the discharge-side rotary shaft. Therefore, a failure due to heat is not likely to occur in the supply-side rotary shaft and the discharge-side rotary shaft. Also, since heat is not easily transmitted to the supply-side rotary shaft and the discharge-side rotary shaft, the overall length of the heat treatment chamber in the axial direction can be set to be long. 
     (7) According to a seventh aspect of the present invention, in any one of the aforementioned configurations (1) to (6), it is preferable that the rotary kiln further includes a cooling section disposed inside the discharge-side rotary shaft to cool the discharge-side rotary shaft. 
     According to this configuration, the discharge-side rotary shaft can be cooled. Therefore, a failure due to heat is not likely to occur in the discharge-side rotary shaft. Also, since the temperature of the discharge-side rotary shaft is not likely to rise, the overall length of the heat treatment chamber in the axial direction can be set to be long. 
     (8) According to an eighth aspect of the present invention, in any one of the aforementioned configurations (1) to (7), it is preferable that the rotary kiln further includes a common drive section that transmits a drive force to the supply-side rotary shaft and the discharge-side rotary shaft. 
     According to this configuration, the number of parts is reduced compared to a case where a drive section exclusively for the supply-side rotary shaft and a drive section exclusively for the discharge-side rotary shaft are provided separately. Also, the drive section requires only a small installation space. Moreover, according to this configuration, it is easier to match the rotational speed of the supply-side rotary shaft and the rotational speed of the discharge-side rotary shaft with each other. 
     (9) According to a ninth aspect of the present invention, in any one of the aforementioned configurations (1) to (8), it is preferable that of a set of the supply-side holder and the supply-side end portion and a set of the discharge-side holder and the discharge-side end portion, one set of the holder and the end portion is coupled to each other so as not to be rotatable relative to each other, and the other set of the holder and the end portion is coupled so as to be rotatable relative to each other. According to this configuration, a torsional force is not likely to be applied to the shell even in the case where the rotational speed of the supply-side rotary shaft and the rotational speed of the discharge-side rotary shaft are different from each other. 
     (10) According to a tenth aspect of the present invention, in any one of the aforementioned configurations (1) to (9), it is preferable that the rotary kiln further includes a gas supply section that supplies an ambient gas to a space radially inward of the shell and a space radially outward of the shell. 
     According to this configuration, an ambient gas can be supplied in accordance with the characteristics of the process material and the material of the shell. In particular, combining this configuration and any one of the aforementioned configurations (2) to (5) facilitates replacement of the shell, so that the kind of the ambient gas can be changed in accordance with a change of the shell. In this way, this configuration allows the common use of the rotary kiln for a plurality of types of process materials and shells. 
     (11) According to an eleventh aspect of the present invention, in any one of the aforementioned configurations (1) to (10), it is preferable that the shell is made of carbon, and a battery material is manufactured by performing a heat treatment on the process material. 
     According to this configuration, the shell is made of carbon. Therefore, contamination of metal scale, which adversely affects the battery material, into the battery material can be suppressed. Thus, degradation in performance of the battery material can be suppressed. Also, the shell made of carbon provides excellent processability. Moreover, the shell made of carbon provides excellent heat shock resistance. 
     (12) In order to address the aforementioned issues, a twelfth aspect of the present invention provides a product manufactured by performing a heat treatment on the process material in the rotary kiln according to any one of the aforementioned configurations (1) to (10). 
     The product according to the present invention is manufactured by the rotary kiln according to the present invention. The rotary kiln according to the present invention provides high versatility for the material of the shell. Therefore, the material of the shell can be selected in accordance with the type of the product. Thus, it is possible to manufacture a desired product without using the shell which contains a component, contamination of which into the product is not preferable. For example, in the case where the product is a battery material, contamination of metal scale into the battery material is not preferable. In this case, contamination of metal scale into the battery material can be suppressed by using a shell made of a non-metallic material (for example, made of carbon). 
     According to the present invention, it is possible to provide a rotary kiln with high versatility for the material and the diameter of a shell. It is also possible to provide a product manufactured by the rotary kiln. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a rotary kiln according to an embodiment of the present invention; 
         FIG. 2  is a transparent front view of the rotary kiln; 
         FIG. 3  is an exploded perspective view of a left portion of the rotary kiln; 
         FIG. 4  is a cross-sectional view of the left portion taken in the left-right direction; 
         FIG. 5  is an enlarged view of a portion inside a circle V of  FIG. 4 ; 
         FIG. 6  is an exploded perspective view of a right portion of the rotary kiln; 
         FIG. 7  is a cross-sectional view of the right portion taken in the left-right direction; 
         FIG. 8  is an enlarged view of a portion inside a circle VIII of  FIG. 7 ; 
         FIG. 9  is a perspective view of a center portion of the rotary kiln; 
         FIG. 10  is a transparent exploded perspective view of a shell of the rotary kiln; 
         FIG. 11  is a transparent front view of the left portion of the rotary kiln during replacement of the shell; 
         FIG. 12  is a transparent front view of the right portion of the rotary kiln during replacement of the shell; 
         FIG. 13  is a transparent front view of the left portion of the rotary kiln during replacement of a screw feeder; and 
         FIG. 14  is a perspective view of a rotary kiln according to the related art. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     A rotary kiln and a product according to an embodiment of the present invention will be described below. 
     &lt;Configuration of Rotary Kiln&gt; 
     First, the configuration of the rotary kiln according to the embodiment is described. In the drawings, the left side corresponds to the supply side (upstream side), and the right side corresponds to the discharge side (downstream side). For convenience of description, three fins  56  of a shell  5  are not shown in drawings other than  FIG. 10 .  FIG. 1  is a perspective view of the rotary kiln according to the embodiment.  FIG. 2  is a transparent front view of the rotary kiln. 
     As shown in  FIGS. 1 and 2 , a rotary kiln  1  according to the embodiment includes a supply part cart  2 , a supply-side support cart  3 , a discharge-side support cart  4 , the shell  5 , a discharge chute  6 , a supply-side coupling tubular portion  7 , a heating section  8 , a platform  90 , and a drive section  91 . 
     [Platform  90 ] 
     The platform  90  has the shape of a plate. The platform  90  is placed on a site of a plant. The platform  90  includes a supply-side track portion  900 , a discharge-side track portion  901 , and a product extraction hole  902 . As shown in  FIG. 2 , the product extraction hole  902  is drilled in the platform  90 . The supply-side track portion  900  includes a pair of rails  900   a . The rails  900   a  are made of steel, and extend in the left-right direction. Stoppers  900   b  are respectively disposed at both ends of the rails  900   a  in the left-right direction. The discharge-side track portion  901  includes a pair of rails  901   a . The rails  901   a  are made of steel, and extend in the left-right direction. Stoppers  901   b  are respectively disposed at both ends of the rails  901   a  in the left-right direction. 
     [Drive Section  91 ] 
     As shown in  FIG. 1 , the drive section  91  includes a motor  910 , a shaft  911 , a supply-side drive sprocket  912 , and a discharge-side drive sprocket  913 . The motor  910  is disposed on the upper surface of the platform  90 . The shaft  911  is coupled to a rotary shaft of the motor  910 . The supply-side drive sprocket  912  is fixed at the left end of the shaft  911 . The discharge-side drive sprocket  913  is fixed at the right end of the shaft  911 . 
     [Supply Part Cart  2 ] 
       FIG. 3  is an exploded perspective view of a left portion of the rotary kiln according to the embodiment.  FIG. 4  is a cross-sectional view of the left portion taken in the left-right direction. As shown in  FIGS. 3 and 4 , the supply part cart  2  includes a lower stage portion  20 , four wheels  21 , four coupling pillars  22 , a middle stage portion  23 , four coupling rods  24 , an upper stage portion  25 , a pair of bearing portions  26 , a screw feeder  27 , a sealing portion  28 , and a supply hopper  29 . The screw feeder  27  is included in the supply section according to the present invention. The sealing portion  28  is included in the gas supply section according to the present invention. 
     The lower stage portion  20  is made of steel, and has the shape of a rectangular plate. A coupling plate  200  is disposed at the right end of the lower stage portion  20 . The four wheels  21  are disposed in the vicinity of the four corners of the lower stage portion  20 . The four wheels  21  can roll in the left-right direction on the pair of rails  900   a . That is, the supply part cart  2  is movable in the left-right direction along the pair of rails  900   a.    
     The middle stage portion  23  is made of steel, and has the shape of a rectangular plate. The middle stage portion  23  is disposed above the lower stage portion  20 . Each of the four coupling pillars  22  has the shape of a rectangular column. The four coupling pillars  22  are interposed between the lower stage portion  20  and the middle stage portion  23 . 
     The upper stage portion  25  is made of steel, and has the shape of a rectangular plate. The upper stage portion  25  is disposed above the middle stage portion  23 . Each of the four coupling rods  24  has the shape of a round bar. The four coupling rods  24  are interposed between the middle stage portion  23  and the upper stage portion  25 . 
     The pair of bearing portions  26  is disposed on the upper surface of the upper stage portion  25 . The pair of bearing portions  26  is arranged in the left-right direction at a predetermined interval between each other. The supply hopper  29  is made of steel, and has the shape of a cone tapered downward. The supply hopper  29  is disposed on the upper surface of the upper stage portion  25 . The supply hopper  29  is disposed on the right side of the pair of bearing portions  26 . A process material A is stored in the supply hopper  29 . 
     The screw feeder  27  includes a screw-housing cylindrical portion  270  and a screw  271 . The screw-housing cylindrical portion  270  is made of steel, and has the shape of a cylinder. The screw-housing cylindrical portion  270  is projected rightward from the lower end of the supply hopper  29 . The screw  271  is housed in the screw-housing cylindrical portion  270 . The screw  271  is driven by a drive force of a motor (not shown) to rotate about its own axis. A shaft portion  271   a  of the screw  271  penetrates through the left wall of the supply hopper  29 . The penetrating end of the shaft portion  271   a  is supported by the pair of bearing portions  26  so as to be rotatable about its own axis. 
     The sealing portion  28  is interposed between the left wall of the supply hopper  29  and the shaft portion  271   a  of the screw  271 . The sealing portion  28  seals a gap between the left wall of the supply hopper  29  and the shaft portion  271   a  while permitting turning of the shaft portion  271   a . The configuration of the sealing portion  28  is the same as the configuration of a sealing portion  35  of the supply-side support cart  3  to be discussed later (see  FIG. 5 ). A nitrogen gas is supplied from the sealing portion  28  as indicated by an arrow Y 1 . The nitrogen gas is included in the ambient gas according to the present invention. The nitrogen gas is diffused inside the supply hopper  29  and inside the screw-housing cylindrical portion  270 . 
     [Supply-Side Support Cart  3 ] 
     The supply-side support cart  3  includes a lower stage portion  30 , four wheels  31 , an upper stage portion  32 , four coupling rods  33 , a pair of bearing portions  34 , the sealing portion  35 , a coupling plate  36 , a supply-side rotary shaft  37 , a supply-side holder  38 , a supply-side gear  390 , a supply-side pinion  391 , and a supply-side sprocket  392 . The sealing portion  35  is included in the gas supply section according to the present invention. 
     The lower stage portion  30  is made of steel, and has the shape of a rectangular plate. A coupling plate  300  is disposed at the left end of the lower stage portion  30 . The coupling plate  300  can be coupled to the coupling plate  200  via a bolt-nut mechanism. That is, the supply-side support cart  3  and the supply part cart  2  can be coupled to each other. The four wheels  31  are disposed in the vicinity of the four corners of the lower stage portion  30 . The four wheels  31  can roll in the left-right direction on the pair of rails  900   a . That is, the supply-side support cart  3  is movable in the left-right direction along the pair of rails  900   a.    
     The upper stage portion  32  is made of steel, and has the shape of a rectangular plate. The upper stage portion  32  is disposed above the lower stage portion  30 . Each of the four coupling rods  33  has the shape of a round bar. The four coupling rods  33  are interposed between the lower stage portion  30  and the upper stage portion  32 . 
     The pair of bearing portions  34  is disposed on the upper surface of the upper stage portion  32 . The pair of bearing portions  34  is arranged in the left-right direction at a predetermined interval between each other. The coupling plate  36  is made of steel, and has the shape of a rectangular plate. The coupling plate  36  is disposed at the right end of the upper stage portion  32 . A supply-side rotary shaft insertion hole  360  is drilled in the coupling plate  36 . The supply-side rotary shaft  37  is made of steel, and has the shape of a cylinder. The supply-side rotary shaft  37  is supported by the pair of bearing portions  34  so as to be rotatable about its own axis. The right end of the supply-side rotary shaft  37  is inserted into the supply-side rotary shaft insertion hole  360 . 
       FIG. 5  is an enlarged view of a portion inside a circle V of  FIG. 4 . As shown in  FIG. 5 , the sealing portion  35  is interposed between the supply-side rotary shaft  37  and the supply-side rotary shaft insertion hole  360 . The sealing portion  35  includes an inner annular portion  350 , an outer annular portion  351 , and a gas pipe  352 . The outer annular portion  351  is made of SUS (Stainless Used Steel)  304 , and has the shape of a bottomed cylinder (cup) opening leftward. The supply-side rotary shaft  37  is inserted through the right bottom wall of the outer annular portion  351 . The side peripheral wall of the outer annular portion  351  is fixed to the inner peripheral surface of the supply-side rotary shaft insertion hole  360 . The inner annular portion  350  is made of SUS  304 , and has the shape of a ring. The inner annular portion  350  seals the left opening of the outer annular portion  351 . The inner annular portion  350  is fixed to the outer annular portion  351 . The gas pipe  352  penetrates through the side peripheral wall of the outer annular portion  351 . A nitrogen gas is supplied from the gas pipe  352  to a space radially inward of the outer annular portion  351  as indicated by an arrow Y 2 . The nitrogen gas is diffused inside the supply-side coupling tubular portion  7  to be discussed later as indicated by an arrow Y 3 . 
     Returning to  FIGS. 3 and 4 , the supply-side holder  38  is made of steel, and has the shape of a bottomed cylinder (cup) opening rightward. The supply-side holder  38  is disposed on the right side of the coupling plate  36 . The supply-side rotary shaft  37  penetrates through the radially inner side of the supply-side holder  38 . The supply-side holder  38  is fixed to the outer peripheral surface at the right end of the supply-side rotary shaft  37 . 
     The supply-side gear  390  is made of steel, and has the shape of a circular plate. The supply-side gear  390  is fixed to the outer peripheral surface of the supply-side rotary shaft  37 . The supply-side gear  390  is disposed between the pair of bearing portions  34 . The supply-side pinion  391  is made of steel, and has the shape of a circular plate. The supply-side pinion  391  is meshed with the supply-side gear  390 . The supply-side sprocket  392  is made of steel, and has the shape of a circular plate. The supply-side sprocket  392  and the supply-side pinion  391  are fixed to an identical shaft. As indicated by dash-dotted lines in  FIG. 1 , a chain  914  is wound between the supply-side sprocket  392  and the supply-side drive sprocket  912 . 
     [Discharge-Side Support Cart  4 ] 
       FIG. 6  is an exploded perspective view of a right portion of the rotary kiln according to the embodiment.  FIG. 7  is a cross-sectional view of the right portion taken in the left-right direction. As shown in  FIGS. 6 and 7 , the discharge-side support cart  4  includes a lower stage portion  40 , four wheels  41 , an upper stage portion  42 , four coupling rods  43 , a pair of bearing portions  44 , a sealing portion  45 , a coupling plate  46 , a discharge-side rotary shaft  47 , a discharge-side holder  48 , a discharge-side gear  490 , a discharge-side pinion  491 , a discharge-side sprocket  492 , and a cooling pipe  493 . The sealing portion  45  is included in the gas supply section according to the present invention. The cooling pipe  493  is included in the cooling section according to the present invention. 
     The lower stage portion  40  is made of steel, and has the shape of a rectangular plate. The four wheels  41  are disposed in the vicinity of the four corners of the lower stage portion  40 . The four wheels  41  can roll in the left-right direction on the pair of rails  901   a . That is, the discharge-side support cart  4  is movable in the left-right direction along the pair of rails  901   a.    
     The upper stage portion  42  is made of steel, and has the shape of a rectangular plate. The upper stage portion  42  is disposed above the lower stage portion  40 . Each of the four coupling rods  43  has the shape of a round bar. The four coupling rods  43  are interposed between the lower stage portion  40  and the upper stage portion  42 . 
     The pair of bearing portions  44  is disposed on the upper surface of the upper stage portion  42 . The pair of bearing portions  44  is arranged in the left-right direction at a predetermined interval between each other. The coupling plate  46  is made of steel, and has the shape of a rectangular plate. The coupling plate  46  is disposed at the left end of the upper stage portion  42 . A discharge-side rotary shaft insertion hole  460  is drilled in the coupling plate  46 . The discharge-side rotary shaft  47  is made of steel, and has the shape of a cylinder. The discharge-side rotary shaft  47  is supported by the pair of bearing portions  44  so as to be rotatable about its own axis. The left end of the discharge-side rotary shaft  47  is inserted into the discharge-side rotary shaft insertion hole  460 . 
     The sealing portion  45  is interposed between the discharge-side rotary shaft  47  and the discharge-side rotary shaft insertion hole  460 . The configuration of the sealing portion  45  is the same as the configuration of the sealing portion  35  of the supply-side support cart  3  discussed earlier (see  FIG. 5 ). A nitrogen gas is supplied from the sealing portion  45  as indicated by an arrow Y 4 . The nitrogen gas is diffused inside the discharge chute  6  to be discussed later. 
     The discharge-side holder  48  is made of steel, and has the shape of a bottomed cylinder (cup) opening leftward. The discharge-side holder  48  is disposed on the left side of the coupling plate  46 . The discharge-side holder  48  is fixed to the left end of the discharge-side rotary shaft  47 . 
     The discharge-side gear  490  is made of steel, and has the shape of a circular plate. The discharge-side gear  490  is fixed to the outer peripheral surface of the discharge-side rotary shaft  47 . The discharge-side gear  490  is disposed between the pair of bearing portions  44 . The discharge-side pinion  491  is made of steel, and has the shape of a circular plate. The discharge-side pinion  491  is meshed with the discharge-side gear  490 . A thickness T 1  of the discharge-side gear  490  is larger than a thickness T 2  of the discharge-side pinion  491 . Therefore, the discharge-side pinion  491  and the discharge-side gear  490  can be meshed with each other even if the discharge-side gear  490  is displaced with respect to the discharge-side pinion  491  in the left-right direction. The discharge-side sprocket  492  is made of steel, and has the shape of a circular plate. The discharge-side sprocket  492  and the discharge-side pinion  491  are fixed to an identical shaft. As indicated by dash-dotted lines in  FIG. 1 , a chain  915  is wound between the discharge-side sprocket  492  and the discharge-side drive sprocket  913 . 
       FIG. 8  is an enlarged view of a portion inside a circle VIII of  FIG. 7 . The cooling pipe  493  is shown in cross section. As shown in  FIG. 8 , the cooling pipe  493  has the shape of a double cylinder, the left end of which is sealed. That is, the cooling pipe  493  includes an inner cylindrical portion  493   a  and an outer cylindrical portion  493   b . Cooling water W is supplied from a water supply pipe  494  to the inner cylindrical portion  493   a  as indicated by an arrow Y 5  in  FIG. 7 . The cooling water W flows leftward through a space radially inward of the inner cylindrical portion  493   a , and turns backward at the left end of the cooling pipe  493 . The cooling water W which has turned backward flows from the inner cylindrical portion  493   a  into the outer cylindrical portion  493   b . The cooling water W having flowed into the outer cylindrical portion  493   b  flows rightward through a gap between the outer cylindrical portion  493   b  and the inner cylindrical portion  493   a , and is discharged from a water discharge pipe  495  to the outside as indicated by an arrow Y 6  in  FIG. 7 . The discharge-side rotary shaft  47 , the pair of bearing portions  44 , the discharge-side gear  490 , the sealing portion  45 , and so forth can be cooled by the cooling water W. 
     [Heating Section  8 ] 
       FIG. 9  is a perspective view of a center portion of the rotary kiln according to the embodiment.  FIG. 9  shows an open state. As shown in  FIG. 9 , the heating section  8  includes a lower divided portion  80 D and an upper divided portion  80 U. 
     The lower divided portion  80 D includes an outer shell  800 D and a heat insulation material  801 D. The outer shell  800 D is made of steel, and has the shape of a rectangular box opening upward. The outer shell  800 D is fixed to the upper surface of the platform  90  via a pair of support blocks  81 . The heat insulation material  801 D is made of a ceramic fiber or a heat insulation brick with a predetermined thickness, and is fixed to the inner surface of the outer shell  800 D. 
     The upper divided portion  80 U includes an outer shell  800 U and a heat insulation material  801 U. The configuration of the upper divided portion  80 U is the same as the configuration of the lower divided portion  80 D. The upper divided portion  80 U and the lower divided portion  80 D are coupled to each other via a hinge portion (not shown). The upper divided portion  80 U can be opened and closed to the lower divided portion  80 D. As shown in  FIG. 9 , in the open state, the upper divided portion  80 U is disposed in rear of the lower divided portion  80 D such that they are arranged side by side. Meanwhile, as shown in  FIGS. 4 and 7 , in a closed state, the upper divided portion  80 U is disposed oppositely above the lower divided portion  80 D. In the closed state, a heating chamber  82  is defined by the heat insulation materials  801 D and  801 U. A heater (not shown) is disposed in the heating chamber  82 . Also, in the closed state, as shown in  FIGS. 4 and 9 , a supply-side shell insertion hole  83  is formed between an outer left portion of the heating section  8  and the heating chamber  82 . In addition, as shown in  FIGS. 7 and 9 , a discharge-side shell insertion hole  84  is formed between an outer right portion of the heating section  8  and the heating chamber  82 . 
     [Shell  5 ] 
     The shell  5  is made of carbon, and has the shape of a cylinder. The shell  5  penetrates through the heating section  8  in the left-right direction. That is, the left end of the shell  5  projects from the supply-side shell insertion hole  83  to the outside. Also, the right end of the shell  5  projects from the discharge-side shell insertion hole  84  to the outside. The body portion of the shell  5  is housed in the heating chamber  82 . The shell  5  is slightly inclined downward from the left to the right. 
       FIG. 10  is a transparent exploded perspective view of the shell of the rotary kiln according to the embodiment. As shown in  FIG. 10 , the shell  5  includes a supply-side partition wall  50 , a discharge-side partition wall  51 , a heat treatment chamber  52 , three discharge holes  53 , five supply-side heat insulation plates  54 , nine discharge-side heat insulation plates  55 , the three fins  56 , a supply-side end portion  57 , and a discharge-side end portion  58 . The supply-side heat insulation plates  54  are included in the supply-side heat insulation portion according to the present invention. The discharge-side heat insulation plates  55  are included in the discharge-side heat insulation portion according to the present invention. 
     The supply-side partition wall  50  has the shape of a circular plate. The supply-side partition wall  50  is disposed in the vicinity of the left end of the shell  5 . A supply-side rotary shaft insertion hole  500  is drilled in the supply-side partition wall  50 . The discharge-side partition wall  51  has the shape of a circular plate. The discharge-side partition wall  51  is disposed in the vicinity of the right end of the shell  5 . The supply-side end portion  57  is disposed on the left side of the supply-side partition wall  50 . The discharge-side end portion  58  is disposed on the right side of the discharge-side partition wall  51 . 
     The heat treatment chamber  52  is defined between the supply-side partition wall  50  and the discharge-side partition wall  51 . As shown in  FIGS. 4 and 7 , the heat treatment chamber  52  is disposed radially inward of the heating chamber  82 . Returning to  FIG. 10 , the discharge holes  53  are disposed on the left side of the discharge-side partition wall  51 . The discharge holes  53  are in communication with the heat treatment chamber  52 . The three discharge holes  53  are disposed at intervals of 120° in the circumferential direction of the shell  5 . 
     The supply-side heat insulation plates  54  are made of a ceramic fiber or a ceramic board, and have the shape of a circular plate. A supply-side rotary shaft insertion hole  540  is drilled in each of the supply-side heat insulation plates  54 . The five supply-side heat insulation plates  54  are disposed in a stacked state on the left side of the supply-side partition wall  50 . That is, the five supply-side heat insulation plates  54  are housed inside the supply-side end portion  57 . The discharge-side heat insulation plates  55  are made of a ceramic fiber or a ceramic board, and have the shape of a circular plate. The nine discharge-side heat insulation plates  55  are disposed in a stacked state on the right side of the discharge-side partition wall  51 . That is, the nine discharge-side heat insulation plates  55  are housed inside the discharge-side end portion  58 . 
     The fins  56  have the shape of a rib. The fins  56  are disposed on the inner peripheral surface of the shell  5 . The fins  56  are disposed between the supply-side partition wall  50  and the three discharge holes  53 . The three fins  56  are disposed at intervals of 120° in the circumferential direction of the shell  5 . 
     As shown in  FIG. 4 , the left end of the shell  5  is housed in the supply-side holder  38 . The supply-side end portion  57  of the shell  5  and the supply-side holder  38  are bolted to each other. The supply-side rotary shaft  37  penetrates through the supply-side rotary shaft insertion holes  540  and  500  of the shell  5  from the left side. That is, the supply-side rotary shaft  37  penetrates through the supply-side end portion  57  from the left side. The opening at the penetrating end of the supply-side rotary shaft  37  is in communication with the heat treatment chamber  52 . 
     As shown in  FIG. 7 , the right end of the shell  5  is housed in the discharge-side holder  48 . The shell  5  and the discharge-side holder  48  are not fixed to each other. Therefore, the shell  5  is movable with respect to the discharge-side holder  48  in the left-right direction and in the circumferential direction. 
     [Supply-Side Coupling Tubular Portion  7 ] 
     As shown in  FIG. 9 , the supply-side coupling tubular portion  7  includes a lower divided portion  70 D and an upper divided portion  70 U. The lower divided portion  70 D is made of steel, and has the shape of a semi-rectangular cylinder opening upward. The lower divided portion  70 D is disposed at the left end of the lower divided portion  80 D of the heating section  8 . A flange divided portion  700 D is disposed at the left end of the lower divided portion  70 D. 
     The upper divided portion  70 U is made of steel, and has the shape of a semi-rectangular cylinder opening upward in an open state. The upper divided portion  70 U is disposed at the left end of the upper divided portion  80 U of the heating section  8 . A flange divided portion  700 U is disposed at the left end of the upper divided portion  70 U. A gas pipe  701 U is projected from the bottom wall of the upper divided portion  70 U in the open state. The gas pipe  701 U is included in the gas supply section according to the present invention. 
     The upper divided portion  70 U can be opened and closed to the lower divided portion  70 D. As shown in  FIG. 9 , in the open state, the upper divided portion  70 U is disposed in rear of the lower divided portion  70 D such that they are arranged side by side. Meanwhile, as shown in  FIG. 4 , in a closed state, the upper divided portion  70 U is disposed oppositely above the lower divided portion  70 D. In the closed state, the flange divided portions  700 D and  700 U are joined together to form a supply-side holder insertion hole  71 . The flange divided portions  700 D and  700 U are coupled to the coupling plate  36  of the supply-side support cart  3  via a bolt-nut mechanism. In the closed state, the left end of the shell  5  is housed inside the supply-side coupling tubular portion  7 . A nitrogen gas is supplied from the gas pipe  701 U into the supply-side coupling tubular portion  7  as indicated by an arrow Y 7 . The nitrogen gas is diffused inside the heating chamber  82  via the supply-side shell insertion hole  83 . 
     [Discharge Chute  6 ] 
     As shown in  FIG. 9 , the discharge chute  6  includes a lower divided portion  60 D and an upper divided portion  60 U. The lower divided portion  60 D is made of steel, and has the shape of a pyramid tapered downward. The lower divided portion  60 D is disposed at the right end of the lower divided portion  80 D of the heating section  8 . A flange divided portion  600 D is disposed at the right end of the lower divided portion  60 D. As shown in  FIG. 7 , the lower end of the lower divided portion  60 D is housed in the product extraction hole  902 . A protection plate  601 D made of carbon is disposed on the inner surface of the tapered portion of the lower divided portion  60 D. 
     Returning to  FIG. 9 , the upper divided portion  60 U is made of steel, and has the shape of a semi-rectangular cylinder opening upward in an open state. The upper divided portion  60 U is disposed at the right end of the upper divided portion  80 U of the heating section  8 . A flange divided portion  600 U is disposed at the right end of the upper divided portion  60 U. 
     The upper divided portion  60 U can be opened and closed to the lower divided portion  60 D. As shown in  FIG. 9 , in the open state, the upper divided portion  60 U is disposed in rear of the lower divided portion  60 D such that they are arranged side by side. Meanwhile, as shown in  FIG. 7 , in a closed state, the upper divided portion  60 U is disposed oppositely above the lower divided portion  60 D. In the closed state, the flange divided portions  600 D and  600 U are joined together to form a discharge-side holder insertion hole  61 . The flange divided portions  600 D and  600 U are coupled to the coupling plate  46  of the discharge-side support cart  4  via a bolt-nut mechanism. In the closed state, the right end of the shell  5  is housed inside the discharge chute  6 . 
     &lt;Motion During Manufacture of Battery Material&gt; 
     Next, the motion of the rotary kiln according to the embodiment during manufacture of a battery material will be described. The battery material is included in the “product” according to the present invention. First, as shown in  FIG. 1 , the motor  910  is driven. The drive force of the motor  910  is transmitted to the supply-side gear  390  via the shaft  911 , the supply-side drive sprocket  912 , the chain  914 , the supply-side sprocket  392 , and the supply-side pinion  391  in this order. In addition, the drive force of the motor  910  is transmitted to the discharge-side gear  490  via the shaft  911 , the discharge-side drive sprocket  913 , the chain  915 , the discharge-side sprocket  492 , and the discharge-side pinion  491  in this order. As shown in  FIG. 2 , the supply-side gear  390  is fixed to the supply-side rotary shaft  37 . The supply-side holder  38  is fixed to the supply-side rotary shaft  37 . The left end of the shell  5  is fixed to the supply-side holder  38 . Therefore, rotation of the supply-side gear  390  causes the shell  5  to rotate. Also, as shown in  FIG. 2 , the discharge-side gear  490  is fixed to the discharge-side rotary shaft  47 . The discharge-side holder  48  is fixed to the discharge-side rotary shaft  47 . Therefore, rotation of the discharge-side gear  490  causes the discharge-side holder  48  to rotate. In this way, the supply-side gear  390  causes the shell  5  to rotate about its own axis, and the discharge-side gear  490  causes the discharge-side holder  48  to rotate about its own axis. 
     Then, as shown in  FIG. 4 , the screw feeder  27  is driven. Then, the process material A is transferred from the supply hopper  29  to the heat treatment chamber  52 . Subsequently, as shown in  FIG. 10 , the process material A is moved rightward with the three fins  56  stirring the process material A inside the rotating shell  5 . The heat treatment chamber  52  is heated in a predetermined temperature pattern by the heating chamber  82 . Therefore, a predetermined heat treatment can be performed on the process material A by causing the process material A to pass through the heat treatment chamber  52 . 
     After that, as shown in  FIG. 7 , a battery material B which is obtained after the heat treatment is ejected from the discharge holes  53  of the rotating shell  5 . The ejected battery material B slides down inside the discharge chute  6  while colliding against the protection plate  601 D. The battery material B which has slid down is stored in a product housing portion (not shown) disposed below the discharge chute  6 . In this way, the battery material B is manufactured by performing a heat treatment on the process material A. 
     During manufacture of the battery material B, as shown in  FIG. 4 , a nitrogen gas is supplied from the sealing portion  28  (arrow Y 1 ) to a space radially inward of the shell  5 . Also, a nitrogen gas is supplied from the sealing portion  35  (arrow Y 2 ) to a space radially outward of the shell  5 . Also, a nitrogen gas is supplied from the gas pipe  701 U (arrow Y 7 ) to a space radially outward of the shell  5 . Moreover, as shown in  FIG. 7 , a nitrogen gas is supplied from the sealing portion  45  (arrow Y 4 ) to a space radially outward of the shell  5 . Thus, a nitrogen gas is supplied to a space radially inward of the shell  5  and a space radially outward of the shell  5  during manufacture of the battery material B. Moreover, as shown in  FIG. 8 , the discharge-side rotary shaft  47  is cooled by the cooling pipe  493  during manufacture of the battery material B. 
     &lt;Motion During Replacement of Shell&gt; 
     Next, the motion of the rotary kiln according to the embodiment during replacement of the shell will be described.  FIG. 11  is a transparent front view of the left portion of the rotary kiln according to the embodiment during replacement of the shell.  FIG. 12  is a transparent front view of the right portion of the rotary kiln according to the embodiment during replacement of the shell. 
     First, as shown in  FIG. 4 , the nuts are removed from the bolts to decouple the coupling plate  36  of the supply-side support cart  3  and the flange divided portions  700 U and  700 D. Also, as shown in  FIG. 7 , the nuts are removed from the bolts to decouple the coupling plate  46  of the discharge-side support cart  4  and the flange divided portions  600 U and  600 D. Moreover, as shown in  FIG. 11 , the bolts are removed to decouple the supply-side end portion  57  of the shell  5  and the supply-side holder  38 . 
     Then, the supply part cart  2  and the supply-side support cart  3  are moved leftward along the pair of rails  900   a . Then, the supply-side rotary shaft  37  and the supply-side holder  38  are taken out of the supply-side coupling tubular portion  7 . In addition, the discharge-side support cart  4  is moved rightward along the pair of rails  901   a . Then, the discharge-side rotary shaft  47  and the discharge-side holder  48  are taken out of the discharge chute  6 . 
     Subsequently, as shown in  FIG. 9 , the supply-side coupling tubular portion  7 , the heating section  8 , and the discharge chute  6  are brought from the closed state into the open state. Bringing the supply-side coupling tubular portion  7 , the heating section  8 , and the discharge chute  6  into the open state exposes the shell  5 . After that, the shell  5  is removed by a jack, a winch, a crane, or the like. 
     Thereafter, a new shell  5  is mounted on the heating section  8 , the supply-side coupling tubular portion  7 , the heating section  8 , and the discharge chute  6  are brought from the open state into the closed state, and the supply part cart  2 , the supply-side support cart  3 , and the discharge-side support cart  4  are brought back in position. Then, the bolts and the nuts are tightened. The shell  5  is thus replaced. 
     &lt;Motion During Replacement of Screw Feeder&gt; 
     Next, the motion of the rotary kiln according to the embodiment during replacement of the screw feeder will be described.  FIG. 13  is a transparent front view of the left portion of the rotary kiln according to the embodiment during replacement of the screw feeder. 
     First, as shown in  FIG. 4 , the nut is removed from the bolt to decouple the coupling plate  200  of the supply part cart  2  and the coupling plate  300  of the supply-side support cart  3 . Then, the supply part cart  2  is moved leftward along the pair of rails  900   a . Then, the screw feeder  27  is taken out of the supply-side rotary shaft  37 . Subsequently, the screw feeder  27  is removed. Thereafter, a new screw feeder  27  is mounted on the supply part cart  2 , and the supply part cart  2  is brought back in position. Then, the bolts and the nuts are tightened. The screw feeder  27  is thus replaced. 
     &lt;Function and Effect&gt; 
     Next, the function and effect of the rotary kiln and the product according to the embodiment will be described. According to the rotary kiln  1  of the embodiment, the supply-side rotary shaft  37  and the discharge-side rotary shaft  47  allow rotation of the shell  5  while securely supporting the rotation axis thereof. Also, a rotational force is transmitted to the shell  5  from the supply-side rotary shaft  37 . Therefore, it is not necessary to dispose a member that allows rotation of the shell  5  while securely supporting the rotation axis thereof (for example, the tires  101   a ,  101   b  in  FIG. 14 ) or a member that transmits a rotational force (for example, the gear  101   c  in  FIG. 14 ) on the outer peripheral surface of the shell. Thus, the shell  5  can be rotated with the rotation axis thereof being securely supported regardless of the material of the shell  5 . In addition, a rotational force can be transmitted to the shell  5  regardless of the material of the shell  5 . Thus, the rotary kiln  1  according to the embodiment provides high versatility for the material of the shell  5 . 
     Also, according to the rotary kiln  1  of the embodiment, it is only necessary to change the supply-side holder  38  and the discharge-side holder  48  in order to change the diameter of the shell  5 . That is, it is not necessary to change the supply-side rotary shaft  37  and the discharge-side rotary shaft  47 . Therefore, the rotary kiln  1  according to the embodiment provides high versatility for the diameter of the shell  5 . 
     According to the rotary kiln  1  of the embodiment, the supply-side holder  38  and the discharge-side holder  48  are attached to the shell  5  so as to be removable in the left-right direction. That is, the shell  5  can be removed from the supply-side holder  38  and the discharge-side holder  48 . This is convenient for inspection, repair, replacement, and so forth of the shell  5 . 
     According to the rotary kiln  1  of the embodiment, the supply-side holder  38  and the supply-side rotary shaft  37  are disposed on the supply-side support cart  3 . Also, the discharge-side holder  48  and the discharge-side rotary shaft  47  are disposed on the discharge-side support cart  4 . Therefore, the supply-side holder  38  and the discharge-side holder  48  are easily movable. That is, the supply-side holder  38  and the discharge-side holder  48  can be easily attached to and removed from the shell  5 . 
     According to the rotary kiln  1  of the embodiment, the process material A can be easily supplied into the shell  5 . Moreover, the left end of the heat treatment chamber  52  can be located in the vicinity of the supply-side end portion  57 . That is, the overall length of the heat treatment chamber  52  in the left-right direction can be set to be long. 
     According to the rotary kiln  1  of the embodiment, the screw feeder  27  is disposed on the supply part cart  2 . Therefore, the screw feeder  27  is easily movable. That is, the screw feeder  27  can be easily inserted into and taken out of the supply-side rotary shaft  37 . This is convenient for inspection, repair, replacement, and so forth of the screw feeder  27 . 
     According to the rotary kiln  1  of the embodiment, the supply-side coupling tubular portion  7 , the heating section  8 , and the discharge chute  6  can be switched between the closed state and the open state. Therefore, a portion of the shell  5  that is housed in the supply-side coupling tubular portion  7 , the heating section  8 , and the discharge chute  6  can be exposed easily. This is convenient for inspection, repair, replacement, and so forth of the shell  5 . This also allows access to the shell  5  from above during replacement of the shell  5 . This facilitates replacement work. 
     According to the rotary kiln  1  of the embodiment, the supply-side heat insulation plates  54  are disposed radially inward of the supply-side end portion  57 . Also, the discharge-side heat insulation plates  55  are disposed radially inward of the discharge-side end portion  58 . Therefore, a failure due to heat is not likely to occur in the supply-side rotary shaft  37  and the discharge-side rotary shaft  47 . Also, since heat is not easily transmitted to the supply-side rotary shaft  37  and the discharge-side rotary shaft  47 , the overall length of the heat treatment chamber  52  in the left-right direction can be set to be long. 
     According to the rotary kiln  1  of the embodiment, the cooling pipe  493  is disposed inside the discharge-side rotary shaft  47 . Therefore, the discharge-side rotary shaft  47 , the pair of bearing portions  44 , the discharge-side gear  490 , the sealing portion  45 , and so forth can be cooled using the cooling water W. Thus, a failure due to heat is not likely to occur in the discharge-side rotary shaft  47 , the pair of bearing portions  44 , the discharge-side gear  490 , the sealing portion  45 , and so forth. Also, since the temperature of the discharge-side rotary shaft  47  is not likely to rise, the overall length of the heat treatment chamber  52  in the left-right direction can be set to be long. 
     According to the rotary kiln  1  of the embodiment, the drive section  91  for both the supply-side rotary shaft  37  and the discharge-side rotary shaft  47  is provided. Therefore, the number of parts is reduced compared to a case where a drive section exclusively for the supply-side rotary shaft  37  and a drive section exclusively for the discharge-side rotary shaft  47  are provided separately. Also, the drive section  91  requires only a small installation space. Moreover, it is easier to match the rotational speed of the supply-side rotary shaft  37  and the rotational speed of the discharge-side rotary shaft  47  with each other. 
     According to the rotary kiln  1  of the embodiment, the supply-side holder  38  and the supply-side end portion  57  are bolted to each other. Therefore, the supply-side holder  38  and the supply-side end portion  57  are not rotatable relative to each other. Meanwhile, the discharge-side end portion  58  is merely housed in the discharge-side holder  48 . Therefore, the discharge-side end portion  58  and the discharge-side holder  48  are rotatable relative to each other. Thus, a torsional force is not likely to be applied to the shell  5  even in the case where the rotational speed of the supply-side rotary shaft  37  and the rotational speed of the discharge-side rotary shaft  47  are different from each other. 
     According to the rotary kiln  1  of the embodiment, an ambient gas can be supplied in accordance with the characteristics of the process material A and the material of the shell  5 . That is, the kind of the ambient gas can be changed when the process material A or the shell  5  is changed. This allows the rotary kiln  1  to be commonly used for a plurality of types of process materials A and shells  5 . 
     The shell  5  of the rotary kiln  1  according to the embodiment is made of carbon. Therefore, contamination of metal scale, which adversely affects the battery material B, into the battery material B can be suppressed. Thus, degradation in performance of the battery material B can be suppressed. Also, the shell  5  made of carbon provides excellent processability. Therefore, as shown in  FIG. 10 , members such as the supply-side partition wall  50 , the discharge-side partition wall  51 , the discharge holes  53 , and the fins  56  can be easily provided in the shell  5 . These members can be provided in the shell  5  by cutting a carbon block or by bolting. Moreover, the shell  5  made of carbon provides excellent heat shock resistance. 
     Also, the heat treatment chamber  52  is disposed radially inward of the shell  5 . Therefore, a heat treatment involves a rise in temperature of the shell  5 . A rise in temperature of the shell  5  may cause oxidation of the shell  5  made of carbon. 
     In this respect, according to the rotary kiln  1  of the embodiment, a nitrogen gas is supplied from each of the sealing portion  28  of  FIG. 4  (arrow Y 1 ), the sealing portion  35  of  FIG. 5  (arrow Y 2 ), the gas pipe  701 U of  FIG. 4  (arrow Y 7 ), and the sealing portion  45  of  FIG. 7  (arrow Y 4 ). Therefore, oxidation of the inner peripheral surface and the outer peripheral surface of the shell  5  can be suppressed. 
     According to the rotary kiln  1  of the embodiment, as shown in  FIG. 7 , the protection plate  601 D made of carbon is disposed in the discharge chute  6 . Therefore, contamination of metal scale into the battery material B from the lower divided portion  60 D made of steel can be suppressed. 
     The rotary kiln  1  of the embodiment can adapt to increases and decreases in overall length of the shell  5  in the axial direction (left-right direction) due to heat of the heating section  8  or the like. That is, as shown in  FIG. 5  illustrating the sealing portion  35 , a slide margin in the axial direction is secured between the inner annular portion  350  and the outer annular portion  351  of the sealing portion  45 . Also, as shown in  FIG. 7 , the pair of bearing portions  44  is each a dry metal bearing that supports the discharge-side rotary shaft  47  so as to be slidable in the axial direction. Moreover, as shown in  FIG. 6 , the thickness T 1  of the discharge-side gear  490  is set to be larger than the thickness T 2  of the discharge-side pinion  491 . Therefore, the discharge-side pinion  491  and the discharge-side gear  490  can be meshed with each other even if the discharge-side gear  490  is displaced with respect to the discharge-side pinion  491  in the left-right direction. The rotary kiln  1  according to the embodiment can thus adapt to increases and decreases in overall length of the shell  5  in the axial direction. 
     In the case where the shell  5  has a double cylinder construction with an outer layer made of a metal and an inner layer made of carbon, the inner layer is generally bolted to the outer layer. With such a construction, a minute gap, that is, an air layer, is likely to be interposed between the inner layer and the outer layer. Therefore, heat is not easily conducted from the outer layer to the inner layer. In contrast, the shell  5  of the rotary kiln  1  according to the embodiment is a one-piece member made of carbon. Therefore, heat is easily conducted from the outer surface to the inner surface. Thus, the shell  5  provides excellent thermal conductivity. 
     The rotary kiln  1  according to the embodiment provides high versatility for the material of the shell  5 . Therefore, the material of the shell  5  can be selected in accordance with the type of the product (in the case of the embodiment, the battery material B). Thus, it is possible to manufacture a desired product without using the shell  5  which contains a component, contamination of which into the product is not preferable. 
     Other Embodiments 
     The rotary kiln and the product according to the embodiment of the present invention have been described above. However, the present invention should not be specifically limited to the embodiment described above. The present invention can also be implemented in various modified or improved forms that may occur to those skilled in the art. 
     For example, the mechanism for rotating the supply-side rotary shaft  37  and the discharge-side rotary shaft  47  is not specifically limited. As shown in  FIG. 2 , a tire may be provided on the supply-side rotary shaft  37  and the discharge-side rotary shaft  47  and rollers may be provided on the supply-side support cart  3  and the discharge-side support cart  4  so that the supply-side rotary shaft  37  and the discharge-side rotary shaft  47  can be rotated by rolling the tire on the rollers. 
     The type of the ambient gas is also not specifically limited. An inert gas (such as helium and argon) or a reducing gas (such as a carbon monoxide gas) may be used. The material of the shell  5  is also not specifically limited. A metal such as Ni (nickel), SUS, and Cu (copper), a ceramic such as SiC (silicon carbide), or carbon may be used. In particular, the rotary kiln according to the present invention is suitably embodied as the rotary kiln  1  having the shell  5  made of a material, on the outer peripheral surface of which it is difficult to dispose a member (such as a tire and a gear), such as a ceramic, carbon, and silica glass, for example. The rotary kiln according to the present invention is also suitably embodied as the rotary kiln  1  having the shell  5  made of a material that is too soft to dispose a member on the outer peripheral surface, such as Cu, for example. 
     As the process material A, LiFePO 4  and carbon powder, which are respectively a cathode material and a anode material for an ferric phosphate lithium-ion battery, may be used, for example. In this case, contamination of carbon of the shell  5  into the cathode material has little effect on the cathode material, compared to a case of contamination of metal scale into the cathode material. Also, contamination of carbon of the shell  5  into the anode material has little effect on the anode material because the anode material itself is made of carbon. Meanwhile, as the product, food, waste, chemicals, chemical raw materials, ceramic raw materials, carbon materials (nano carbon), and so forth may be used, for example, as well as the battery material B. The properties of the process material A and the product are also not specifically limited. For example, the process material A and the product may be powdery, particulate, massive, liquid, or foamed. The process material A and the product may be a contamination of two or more thereof. The particle shapes of the process material A and the product may be perfectly spherical, ovally spherical, polyhedral, or needle-shaped, or may be an irregular shape obtained by appropriately incorporating these shapes.