Abstract:
A rotary joint for a heat transfer drum using a stationary syphon pipe system. The syphon pipe is supported on a syphon tube adjustably mounted upon the rotary joint body whereby the distance between the syphon pipe intake and the drum shelf can be very accurately adjusted and maintained. Also, the syphon pipe is mounted upon the syphon tube in a pivotal manner to permit ready installation of the syphon system and employs a locking threaded sleeve arrangement assuring accurate location of the syphon pipe relative to the syphon tube upon the syphon pipe pivoting to its operative position.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention pertains to rotary joints supplying steam to rotating heat transfer drums using stationary syphons for condensate removal. 
     2. Description of the Related Art 
     Rotating heat transfer drums such as of the type used in paper, corrugated paper and cardboard manufacture usually employ steam to heat the drum and a rotary joint located at the end of a hollow drum journal is used to introduce the steam into the drum interior. As the steam condenses within the drum, the condensate is removed through a rotary joint, usually the same joint which introduced the steam, and it is common for rotary joints to include both steam inlet ports and condensate exit ports. 
     Syphon systems for removing condensate from rotating heat transfer drums are either of the “rotating” type where the conduit pickup occurs at a shoe contacting the drum interior and wherein the syphon structure within the drum rotates with the drum, or the syphon system may be of the “stationary” type wherein the condensate pickup apparatus extends into the drum interior, but does not rotate with the drum, and includes a condensate pickup port disposed adjacent the drum shell interior. 
     Whether a heat transfer drum employs a rotating syphon system or a stationary syphon system depends on various factors including cost, size of the drum, rate of drum rotation, material to be heated and other factors. Both types are well known in the dryer drum art. 
     The installation of a rotating syphon system usually requires that considerable installation work occurs within the drum interior. This is not a problem with large size dryer drums which have access openings located in the drum ends. However, with smaller sizes of drums, it is usually necessary to employ a stationary syphon system whereby the syphon structure may be inserted through the hollow drum journal, and once inserted, the syphon pipe portion of the syphon system is moved to an operating location within the drum adjacent the drum shell inner surface for removing condensate therefrom. Samples of such stationary syphon systems are shown in U.S. Pat. Nos. 2,542,287; 2,732,228; 3,265,411; 4,590,688 and 5,533,569. 
     It has long been recognized that the puddle of condensate which accumulates in the lower region of the dryer drum creates problems. This condensate accumulation “tumbles” within the drum as it rotates requiring excessive power, and deleteriously affects the heat transfer from the steam within the drum to the drum shell. In rapidly rotating larger drums, this condensate forms a film throughout the drum periphery, and can be effectively removed by a rotating syphon system wherein the condensate film is removed and maintained of minimum thickness. With a stationary syphon system, condensate is only removed at the lower region of the drum, and the condensate accumulation in the lower region of the drum will exist unless the drum rate of rotation is high enough to cause the condensate to “film” about the drum periphery. 
     Because of the “insulation” effect that condensate accumulation has on heat transfer from the steam to the drum, it is particularly important when manufacturing corrugated fluted paper and cardboard to be able to accurately maintain the temperature of the drum very closely as to accurately control the humidity content of the paper being dried by the drum. Heretofore, stationary syphon systems often fail to maintain the desired distance between the syphon pipe intake and the drum shell interior surface as to minimize the condensate accumulation and provide optimum uniform heat transfer characteristics and control to the drum. Prior stationary syphon systems required that the spacing of the syphon pipe inlet from the drum interior surface be determined by regulating the length of the syphon pipe, and due to manufacturing tolerances in drum manufacture, and because of variations in rotary joint installations, it is very common that a greater spacing exists between the syphon pipe pickup entrance and the drum shell than is desired, resulting in an excessive accumulation of condensate and uneven heating of the drum shell. 
     OBJECTS OF THE INVENTION 
     It is an object of the invention to provide a rotary joint for a rotating heat transfer drum using a stationary syphon system wherein the syphon system can be very accurately adjusted relative to the drum periphery after installation of the rotary joint. 
     Another object of the invention is to provide a rotary joint for a rotating heat transfer drum having a stationary syphon system wherein accurate radial positioning of the syphon system relative to the axis of drum rotation is readily achieved exteriorly of the rotary joint. 
     Yet another object of the invention is to provide a rotary joint for a rotating heat transfer drum having a stationary syphon system including a horizontal syphon tube and a vertically disposed syphon pipe wherein the pipe is pivotally mounted upon the inner end of the tube, which is located within the drum, and the pipe is firmly mechanically oriented to the support tube when in the operative position, and locked in the operative position. 
     An additional object of the invention is to provide a rotary joint for a rotating heat transfer drum having a stationary syphon system wherein a substantially vertically oriented syphon pipe is pivotally mounted upon the inner end of a horizontal syphon tube and a threaded interconnection exists between the pipe and tube when the pipe is in the operative condensate removing position, and the threaded interconnection is achieved after the syphon system has been inserted into the drum interior. 
     SUMMARY OF THE INVENTION 
     A rotary joint in accord with the invention is mounted upon a stationary support located adjacent the drum journal. A steam inlet defined in the rotary joint introduces steam into the drum journal through a rotary seal arrangement. 
     A syphon tube support is mounted upon the outer end of the rotary joint body and serves as the support for a horizontally disposed syphon tube which extends through the rotary joint body and the hollow drum journal, and includes a syphon pipe mounted upon its innermost end within the drum. 
     The syphon tube support is mounted upon the rotary joint body in such a manner as to permit the syphon tube support to be vertically positioned relative to the rotary joint body which, in turn, vertically positions the syphon tube and syphon pipe associated therewith. This vertical adjustment of the syphon tube support is achieved through a threaded screw arrangement, and as the syphon tube is supported at axially spaced locations on the tube support, and is thereby cantilever mounted at its outer end, the vertical adjustment of the syphon tube support results in an equal vertical adjustment of the location of the syphon tube relative to the rotary joint body, and the axis of drum rotation. The syphon tube support includes a port in communication with the syphon tube whereby the condensate may be removed therefrom. 
     The syphon pipe is pivotally mounted upon the inner end of the syphon tube whereby the syphon pipe may be pivoted to an installation position locating the pipe relatively parallel to the length of the syphon tube. In such an orientation, the syphon pipe, and syphon tube, can be readily inserted through the hollow drum journal. Once the syphon pipe is within the interior of the drum, and is not supported by the drum journal, the syphon pipe will pivot downwardly under gravitational force. This syphon pipe movement will locate the condensate entrance or intake of the syphon pipe relatively close to the interior of the drum periphery or shell, but gravitational force will not usually fully pivot the syphon pipe to its operative position. 
     The inner end of the syphon tube includes a threaded sleeve adapted to be received within a threaded bore defined in the upper end of the syphon pipe once the syphon pipe is in its operative position. To this end, a torque transfer tool is inserted through the outer end of the syphon tube to engage torque transfer means defined on the threaded sleeve whereby the threaded sleeve may be readily rotated to cause the sleeve to thread into the bore defined on the upper end of the syphon pipe for locking the syphon pipe into its operative position in a fluid tight relationship to the syphon tube. 
     As mentioned above, usually the syphon pipe will not have pivoted under gravitational force to its full operative position. Accordingly, the torque tool inserted through the syphon tube, includes an alignment projection which will engage the threaded bore of the syphon pipe to pivot the syphon pipe threaded bore into alignment with the threaded sleeve which permits further rotation of the threaded sleeve to cause the sleeve to thread into the syphon pipe bore. A shoulder defined on the syphon tube inner end engages with a head defined on the threaded sleeve against which the sleeve may be tightened to tightly draw the syphon pipe into its operative position and accurately locate the syphon pipe inlet to the drum shell inner surface. 
     After the aforementioned assembly of the syphon pipe to the syphon tube has been completed, very accurate adjustment of the syphon pipe inlet to the drum shell is produced by adjusting the location of the syphon tube support on the rotary joint body, and in this manner, a more accurate location of the syphon pipe inlet to the drum shell can be achieved than was heretofore possible, minimizing the amount of condensate which can accumulate within the drum. 
     The positive locking of the syphon pipe to the syphon tube assures that the syphon pipe will be disposed in the vertical “6o&#39;clock” position placing the syphon pipe inlet into the center of the accumulated condensate, insuring effective condensate removal. 
     To remove the syphon system from the drum, it is only necessary to reinsert the torque transfer tool through the syphon tube into the threaded sleeve, rotate the threaded sleeve in an unlocking direction to remove the sleeve from the syphon pipe threaded bore, and upon the completion of such operation, the syphon tube and pipe can readily be withdrawn through the drum journal as the syphon pipe will pivot to its installation position during such withdrawal. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawings wherein: 
     FIG. 1 is an elevational diametrical sectional view of a rotary joint and drum journal in accord with the invention, 
     FIG. 2 is an enlarged detail elevational sectional view of the rotary joint of FIG. 1 illustrating the configuration of the syphon tube support in greater detail, 
     FIG. 3 is an exterior perspective view of a rotary joint constructed in accord with the invention, 
     FIG. 4 is an elevational diametrical sectional detail view of a modification of the syphon tube support when the rotary joint of the invention is used with a rotating syphon system, 
     FIG. 5 is an elevational detail sectional view of the inner end of the syphon tube, and the syphon pipe, during installation or removal of the syphon system relative to the drum, 
     FIG. 6 is an elevational detail sectional view illustrating a partial pivoting of the syphon pipe toward the operative position, the torque transfer tool being shown in position within the threaded sleeve, 
     FIG. 7 is a view similar to FIG. 6 illustrating the alignment projection on the torque transfer tool engaging the syphon pipe threaded bore to align the threaded bore with the syphon tube sleeve, and 
     FIG. 8 is a sectional view similar to FIGS. 6 and 7 illustrating the syphon pipe in the full operative position, and the torque transfer tool has been removed from the syphon tube. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A rotary joint in accord with the invention is shown in section in FIG. 1 wherein the rotary joint is generally indicated at  10 . The purpose of the rotary joint  10  is to introduce, and remove, a heat transfer medium, such as steam, into a rotating dryer drum such as used in the manufacture of paper, corrugated paper and cardboard, and such a drum includes a cylindrical drum journal  12 , FIG. 1, a radial drum end wall  14 , and the periphery or shell of the drum is defined by a cylindrical shell  16  shown schematically in FIGS. 7 and 8. The paper or cardboard web to be dried, not shown, passes over the exterior of the shell  16  absorbing the heat of the drum. 
     A stationary support plate  18 , FIG. 1, includes an opening  20  through which the drum journal  12  extends. The bearings supporting the journal are not illustrated, and the drum journal will be rotating within the support opening  20 . A cylindrical bracket  22  is bolted upon the support  18  by bolts  24  concentric to the opening  20 , as will be appreciated from FIG.  1 . 
     The rotary joint body  26  is mounted upon the bracket  22  by threaded studs  28  affixed to the bracket  22  and these studs extend through holes in the body flange whereby tightening of the nuts  30  fixes the rotary joint body  26  upon the bracket  22  in a stationary manner. This relationship is apparent from FIG.  3 . 
     Internally, the rotary joint body  26  includes a chamber  32  having an inlet port  34  into which steam is introduced through appropriate piping and conduit systems, not shown. The chamber  32  includes a reciprocal piston  36  guided upon piston pins  38 , and the piston  36  includes a flat surface engaging the annular seal ring  40  which engages the conical seal surface of the wear plate  42 . The wear plate  42  is mounted upon the end of the drum journal  12  by bolts  44  whereby the wear plate  42  will rotate with the drum journal. A spring  46  biases the piston  36  to the right, FIG. 1, insuring engagement of the piston, seal ring  40  and the wear plate  42  even though the body chamber  32  is not pressurized. 
     The rotary joint body  26  includes a flat outer face  48  against which the syphon tube support  50  is mounted. The syphon tube support  50  and the joint body  26  are sealed in a fluid tight relationship by the annular seal  52 . An annular retaining ring  54 , FIG. 3, is located around the outer end of the syphon tube support  50  and is mounted upon the rotary joint body  26  by six bolts  56  threaded into the rotary joint body. As will be appreciated from FIGS. 1 and 2, the bolts  56  extend through the oversized holes  58  defined in the syphon tube support. A central opening  60  is defined in the retaining ring  54 , and a threaded cap screw  62  functions as adjustment means for radially positioning the syphon tube support  50  on the rotary joint body  26 , as later described. 
     The steam condensate is removed from the drum by a syphon system which includes the horizontal syphon tube  64  which extends through the drum journal  12 , the wear plate  42 , the piston  36  and the rotary joint body chamber  32 . The syphon tube  64  is keyed against rotation relative to the body  26  by key  66 , FIGS. 1 and 2, and the syphon tube includes a conical enlargement or boss  68  spaced from its outer end. A plurality of openings  70  are defined in the syphon tube  64  between the boss  68  and the end of the syphon tube, and these openings  70  communicate with the chamber  72  of the syphon tube support. The chamber  72  is in communication with the port  74  defined in the syphon tube support through which the condensate is removed via a conventional hose and conduit system, not shown. 
     The outer end of the syphon tube  64  is sealed by a nut  76  threaded into internal threads defined in the syphon tube end, and the nut  76  includes a thin radially extending washer-type head  78  of a diameter larger than the opening  60  defined in the retaining ring  54 . The syphon tube support  50  includes a conical bore  80  which receives the syphon tube conical boss  68  in a complementary manner, and the outer end of the syphon tube is received within cylindrical bore  82  defined in the syphon tube support  50 . Accordingly, upon tightening of the nut  76 , the conical boss  68  is tightly drawn into engagement with the conical bore  80 , and the end of the syphon tube is closely received within cylindrical bore  82 . In this manner, the syphon tube  64  is supported at its outer end in a cantilever manner by the syphon tube support  50 . 
     The inner end of the syphon tube  64  is threaded and has an end fitting  84  threaded thereon. The end fitting  84  includes an internal chamber  86  which is coaxial with the bore of the syphon tube  64 , and the chamber  86  includes a concentric annular shoulder  88 . A tubular threaded sleeve  90  is rotatably mounted within the chamber  86  and is axially positionable therein. The sleeve threads  92  are defined on a stem which is slidably received within the fitting bore  94 , and a head  96  defined on the sleeve  90  includes abutment surfaces adapted to engage the fitting shoulder  88 , as later described. The sleeve head  96  is formed with a hexagonal bore  98  communicating with the sleeve bore, and this hexagonal bore constitutes torque transfer means for the sleeve as will be later appreciated. 
     The syphon pipe fitting  100  is pivotally mounted upon the syphon tube fitting  84  by pivot  102 , and includes a chamber  104 . The syphon pipe  106  is affixed within the fitting  100  in communication therewith, and a threaded bore  108  having an axis transversely disposed to the length of the syphon pipe  106  is defined in the fitting  100  in communication with chamber  104 . 
     The lowermost end of the syphon pipe  106  mounts the syphon shoe  110  having the inlet opening  112  defined therein. 
     The syphon pipe fitting  100  includes a flat surface  114  which is ultimately engageable with a flat surface  116  defined on the end fitting  84 , as described below. 
     The torque transfer tool for rotating the sleeve  90  is shown at  118  in FIGS. 6 and 7. This torque transfer tool comprises an elongated rod of greater length than the syphon tube  64 , and the tool includes a hexagonal head  120  which is receivable within the sleeve head hexagonal bore  98 . A cylindrical pilot end  122  is defined on the tool  118  for reception within the sleeve bore during sleeve tightening. 
     An axially extending alignment projection  124 , FIGS. 6 and 7, extends from the tool pilot end, and its purpose is to aid in aligning the syphon pipe threaded bore  108  with the threads  92  of the sleeve  90  for properly positioning the syphon pipe  106  to its operative position. 
     The rotary joint and syphon structure described above is installed as follows: 
     Initially, the rotary joint body  26  is mounted upon the stationary support  18  in the apparent manner, and prior to the rotary joint body being mounted upon the bracket  22 , the wear plate  42  will have been mounted upon the end of the drum journal  12 . Thereupon, the rotary joint body  26  can be mounted upon the bracket  22  in the apparent manner. At this time, the syphon tube support  50  will not be mounted upon the body  26  by bolts  56 . 
     At this time, the syphon tube  64  is mounted to the syphon tube support  50 . The syphon tube is rotatively oriented to the syphon tube support by means of the key  66  received within a slot defined in the syphon tube, and received within a notch defined in the syphon tube support. In this manner, angular orientation of the syphon tube to the syphon tube support  50 , on the vertical, is assured. The nut  76  is threaded into the internal threads in the end of the syphon tube  64 , and tightened, which draws the syphon tube conical boss  68  into firm engagement with the conical bore  80  and the end of the tube  64  into bore  82 , and the syphon tube  64  will be firmly connected to the syphon tube support  50  in a non-rotative manner. 
     Thereupon, the syphon structure is inserted through the wear plate  42  and through the drum journal  12 . To permit this installation, the syphon pipe fitting  100  must be oriented parallel to the length of the syphon tube  64  by pivoting the fitting  100  about pivot  102 , as shown in FIG.  5 . In FIG. 5, the syphon pipe  106  is shown in its installation position which permits the syphon tube  64  to be fully inserted into the rotary joint, drum journal and drum until the flat face on the syphon tube support engages the rotary joint body face  48 , and these faces engage the seal  52 . The bolts  56  may now be preliminarily tightened to affix the syphon tube support  50  to the body  26 . 
     Once the syphon pipe fitting  100  has been inserted into the drum interior past the drum journal  12 , gravitational forces will cause the syphon pipe fitting  100  and syphon pipe  106  to pivot in a clockwise direction, FIGS. 6 and 7. The position of the syphon pipe structure at this time will be approximately that shown in FIGS. 6 and 7. At this time, the nut  76  is removed from the outer end of the syphon tube  64 , and the torque transfer tool  118  is inserted into the syphon tube  64  through its outer end until the hexagonal head  120  is received within the hexagonal recess  98  defined in the sleeve  90 . The tool  118  can be used to push the sleeve  90  within the chamber  86  until the end of the sleeve and the end of the tool  118  engage the upper end of the syphon pipe fitting  100 . Clockwise rotation of the tool  118  and sleeve  90  causes the alignment projection  124  to engage the syphon pipe fitting threaded bore  108  pivoting the syphon pipe fitting  100  in a clockwise direction, FIG. 7, aligning the threaded bore  108  with the threads  92  of sleeve  90 . Continued rotation of the tool  118  causes rotation of the sleeve  90  and threads the threaded stem of the sleeve into the syphon pipe fitting bore  108 . Rotation of the tool  118  continues until the head  96  of the sleeve engages the shoulder  88  of the end fitting  84 , and at this time, a firm mechanical connection has been made between the syphon tube  64  and the syphon pipe  106 . Tightening of the sleeve  90  establishes a fluid tight relationship between the syphon tube and syphon pipe, and draws the surfaces  114  and  116  into tight relationship as shown in FIG.  8 . 
     Thereupon, the tool  118  is withdrawn from the syphon tube  64  and the syphon tube and syphon pipe will be in unrestricted fluid communication with each other. The nut  76  is then threaded into the outer end of the syphon tube  64  to maintain the firm cantilevered support of the syphon tube on the syphon tube support  50 . 
     Thereupon, the bolts  56  are somewhat loosened, and the vertical position of the syphon tube support  50  on the rotary joint body  26  is very accurately adjusted by rotation of the cap screw  62  mounted in the retaining ring  54  whose end bears against an axial shoulder defined on the syphon tube support  50  as will be appreciated in FIGS. 1 and 2. This vertical adjustment of the syphon tube support  50  is permitted by the oversized holes  58  through which bolts  56  extend. 
     The adjustment screw  62  is adjusted to very accurately space the syphon pipe shoe  110  from the inner surface of the drum shell  16  in order to minimize the depth of condensate within the lower portion of the drum. The adjustment screw  62  permits five adjustment of the position of the syphon pipe shoe  110  and inlet  112  relative to the drum after assembly of the components assuring the most accurate positioning of a stationary syphon heretofore attained without scraping the syphon shoe on the drum shell, which would cause excessive wear. Once the syphon structure is properly radially positioned relative to the axis of drum rotation, the bolts  56  are tightened which forces the retaining ring  54  against the syphon tube support  50  which, in turn, frictionally engages the face  48  of the joint body  26  fixing the vertical position of the syphon structure. 
     From the above description, it will be appreciated that a stationary syphon may be accurately located relative to the drum shell. It will be appreciated that the sequence of assembly steps may vary somewhat from those described above without departing from the novel aspects of the invention. For instance, if the syphon tube end fitting  84  is too large to fit through the bore of the wear plate  42 , the syphon tube could be previously inserted through the wear plate prior to it being mounted upon the drum journal, and other sequences of assembly can be varied as within the scope of knowledge of one skilled in the art. Because the key  66  will insure that the syphon pipe  106  is properly oriented to the vertical, the use of the key assures that the syphon system will remove the maximum amount of condensate from the drum, and the firm cantilevered support of the syphon tube assures radial positioning of the entire syphon system. The type of rotary joint described above can be used with a rotary syphon pipe system, and in such event, the structure shown in FIG. 4 is utilized wherein previously described components are indicated by primed reference numerals. When using the rotary joint body with a rotary syphon system, the syphon tube support  126  includes a flat face  128  and seal  130  whereby tightening of the bolts  132  draws the syphon tube support  126  into a firm sealed relationship to the body surface  48 ′. 
     The horizontal rotating syphon pipe  133 , at its inner end, is in communication with the rotating syphon structure mounted within the drum interior, not shown, and the outer end of the syphon pipe communicates with the port  134  defined in the syphon tube support  126 . The syphon tube outer end is supported within a bearing  136  mounted in the syphon tube support, and a smaller diameter tube bearing surface  138  is defined upon the syphon tube. Conventional bearing retaining rings are employed to maintain the bearing  136  within the tube support  126 . 
     From the above, it will be appreciated how the rotary joint body  26  may be utilized, without modification, with a rotary syphon system. 
     It is appreciated that various modifications to the inventive concepts may be apparent to those skilled in the art without departing from the spirit and scope of the invention.