Abstract:
This disclosure relates to an expansion joint to connect two or more concentric bodies that are heated/cooled to different temperatures for the passage of liquid or gases. When the connecting portion is at an angle not in plane with the concentric bodies, the design allows for the gravity drainage of fluids and slurries from one connecting body to another without pooling or damming.

Description:
BACKGROUND 
     In various chemical processes, gases and/or liquids need to pass from one tank to another. For example, in some spray drying processes, hot air from a ring main duct is injected radically into a concentric dryer shell through equally spaced ports. In such processes, the portions connecting the tanks (concentric bodies) has been known to fail or have unacceptable performance due to expansion differences of the two bodies resulting from their dissimilar temperatures. In addition, the connecting parts, or expansion joints, are typically at an angle different from the plane of the concentric bodies to allow for the drainage of fluids or slurries from one body to another. Expansion of angled components has lead to the design of relatively complicated expansions joints. 
     Traditionally these expansion joints are of two types, multi-layer flexible high temperature fabric and steel meshes that flex to allow for expansion differences or a bellows style steel expansion joint. These two types of expansion joints can have unacceptable performance for a variety of reasons. For example, uneven puckering of the flexible type causes air flow imbalance between the many connecting ports, chemicals attack the fabrics which are heat resistant but not chemical resistant and the pooling or damming of fluids in the bellows prevent complete gravity draining from one body into the other body. Also, due to the need for custom shape and dimension, these types of joints can be cost prohibitive. 
     Therefore, there is a need for a low cost expansion joint that would allow for different expansion rates of two or more concentric bodies. There is also a need for an expansion joint between two or more concentric bodies that can completely gravity drain without pooling or damming as the bodies expand and/or contract. 
     SUMMARY 
     The present disclosure provides a connection between two or more concentric bodies having different expansion rates. The connection is particularly useful when the connection is angled with respect to the horizontal plane defined by at least one of the concentric bodies. This angled connection allows for complete gravity drainage of fluids that pass through the connection. In a most preferred embodiment, the expansion joint is a slip joint design with two tubes of different dimensions to create a minimum gap between the tube surfaces. Because expansion occurs radically between the bodies, the outer concentric body is preferably supported on lubricated skids at the same angle as the expansion joint in order to allow expansion in the same plane defined by the joint. 
     In a most preferred embodiment, the expansion joint is a slip joint made from two different dimensioned connecting portions with the smaller connecting portion connected to the concentric body that has the connection point higher than the connection point of the other body. This allows for gravity drainage not to be impeded due to the dimensional differences. The connecting portions preferably overlap enough to not separate when full expansion has occurred. The gap between the connecting portions can be filled with a heat resistant gasket, most preferably, with a heat resistant ‘tadpole’ gasket that is held in place with a backing flange. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective, cutaway view of two concentric bodies showing two expansion joints and two skid plates that exemplify the present disclosure; 
     FIG. 2 is a side elevational view in partial cutaway showing the connection of two concentric bodies by a preferred expansion joint; 
     FIG. 3 is a cutaway view of a preferred system for sealing the gap between two expansion joint members; and 
     FIG. 4 is a top plan view of a preferred skid plate. 
    
    
     DETAILED DESCRIPTION 
     With reference to FIG. 1, two concentric bodies  10  and  20  are connected by two sets of expansion joints  30  and  40 . The number of expansion joints is unlimited and are preferably evenly distributed and symmetrically placed between the inner ( 20 ) and outer ( 10 ) concentric bodies. Also shown in FIG. 1 are two sets of support skid plates  50  and  60 . The skid plates allow for free movement of outer concentric body  10  relative to inner concentric body  20 . This movement is described in greater detail with respect to FIG. 2, below. 
     A side view of two concentric bodies with a preferred connecting expansion joint  40  is shown in FIG.  2 . The angle ⊖ of the expansion joint relative to a horizontal plane connection x—x intersecting body  20  is set to allow for gravity drainage of fluids from elevated concentric body  10 . As shown, ⊖ is preferably between 0° and 90° and most preferably between 25° and 65°. Turning to expansion joint  40 , larger, outer connecting lining  42  is located and fixed to concentric body  20 . Smaller, inner connecting lining  44  is fixed to body  10  and is preferably disposed at an angle ⊖′ relative to horizontal plane x—x, that is the same or substantially the same as ⊖. Again, this allows for material to drain without creating a damming or pooling effect. The outer and inner linings can be flange mounted (not shown) to the concentric bodies to allow for easy replacement or removal. The gap between linings  42  and  44  should be small enough to allow proper sealing of the gap. The outer and inner linings are preferably generally tubular and are constructed from a rigid material such as metal, polymer, plastic, ceramic or glass. 
     Also shown in FIG. 2 are support members  12  and  14  disposed between outer concentric body  10  and upper support shoe  62  of skid plate assembly  60 . Lower shoe  66  of skid plate assembly  60  is secured to support members  16  and  18  which are preferably fixedly secured to the ground or other suitable structure. Skid plate  64  is disposed between the upper and lower support shoes. 
     Preferably plate assembly  60  is disposed at an angle ⊖″ relative to axis y—y wherein axis y—y is parallel to axis x—x passing through body  20 . ⊖″ is preferably the same or substantially the same as ⊖ and ⊖′. 
     FIG. 3 shows a gasket  70  that is suitable for sealing gap G between connecting linings  42  and  44 . Gasket  70  is preferably a circular “tadpole” design fabricated from chemical resistant rubber, plastic or other suitable material. Head  72  of tadpole gasket  70  is positioned in gap G to peripherally contact the exterior of inner lining  44  to prevent or reduce the likelihood of gases, liquids, etc . . . from escaping from the system. Body  74  of gasket  70  can be secured to outer connecting lining  42  by providing gasket flange  46 . Gasket flange  46  is preferably fabricated having a first flange portion  46 A that is integrally formed with outer connecting lining  42  and a second backing flange portion  46 B that is movable relative to first flange portion  46 A. Bolt assembly  48  or other suitable compression means is used to secure gasket body  74  to flange portion  46 A. 
     Turning to FIG.  4  and with reference to FIG. 2, skid plate  64  is attached to only one of the support shoes  62  or  66 . Slots  80  are formed in skid plate  64  to allow for relative movement between skid plate  64  and either shoe  62  or  66 , whichever is not attached to the skid plate. Skid plate  64  is preferably impregnated with a lubricant such as oil or graphite to allow for slippage. This can be accomplished by purchasing such a plate or by filling void spaces  82  in the plate with lubricants. 
     In operation, expansion/contraction of concentric body  10  relative to concentric body  20  results in a telescoping of inner connecting lining  40  relative to outer connection lining  42 . Because both connecting linings and skid plate assembly  60  are generally disposed at the same angle 1  the gap G between the outer surface of inner connecting lining  44  and the inner surface of outer connecting lining  42  remains generally constant during relative movement (shown by arrows A and B). By maintaining a predictable or known gap, it is possible to provide a proper seal between the two connecting members 
     If the connecting linings were horizontal, gravity would not facilitate drainage. If the moving concentric body were not on an angled skid plate, the gap between the telescoping connecting portions would vary upon movement, potentially compromising the seal. 
     While various preferred embodiments are shown and described, it is understood that one skilled in the art could modify the present disclosure without departing from the scope and spirit of the invention set forth in the claims appended hereto.