Abstract:
A reversible nozzle ( 10 ), removably attached to a fluid emitting base, such as a half turbine casing ( 22 ). The reversible nozzle ( 10 ) has a nozzle body ( 16 ) and a nozzle tube ( 12 ), with the nozzle body ( 16 ) preferably forming a plurality of fastener receiving slots ( 18, 18   a ). The nozzle tube ( 12 ) is angled with respect to the nozzle body ( 16 ). An installed reversible nozzle ( 10 ) is reversed by removing fasteners ( 34 ) connecting the nozzle body ( 16 ) to the fluid emitting base ( 22 ), rotating the nozzle body ( 16 ) about a normal nozzle body axis X, and resecuring the reversible nozzle ( 10 ) to the fluid emitting base ( 22 ) with fasteners ( 34 ). To aid in the alignment of the reversible nozzle ( 10 ), one fastener receiving slot ( 18   a ) is preferably elongated.

Description:
This application claims benefit of U.S. Provisional Application Ser. No. 60/107,160, filed Nov. 5, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to nozzles and, more particularly, to reversible nozzles used in steam turbines. 
     2. Brief Description of the Prior Art 
     Nozzles are used in a variety of applications, one of which is directing steam in steam turbines. Steam turbines utilize nozzles to direct high pressure steam or gas toward turbine blades. For example, turbine nozzles are discussed in U.S. Pat. Nos. 1,750,652; 4,066,381; 4,097,188; 5,259,727; and 5,392,513. The high pressure gas exits the nozzles at high velocities and contacts the turbine blades causing the blades to rotate. The nozzles are typically installed in two ways. In one arrangement, a plurality of nozzles is assembled into a nozzle plate or ring and bolted into the turbine. Another arrangement involves drilling the turbine casing and then positioning and welding the nozzles into place. 
     From time to time, installed nozzles wear and must be removed and replaced. Further, depending on the turbine design, differently oriented nozzles are used to cause the turbine blades to rotate in either a clockwise direction or a counterclockwise direction. If the direction of rotation is to be changed, the nozzle must be removed and realigned. These are all time-consuming and expensive endeavors, especially if the nozzles are welded in place. 
     Therefore, it is an object of the present invention to provide nozzles which can be installed, removed, or reversed without welding. 
     SUMMARY OF THE INVENTION 
     The present invention generally relates to reversible nozzles removably connected to a fluid emitting base, with each nozzle having a nozzle tube and a nozzle body. Each nozzle tube defines a fluid inlet, a fluid exit aperture, and a nozzle passageway connecting the fluid inlet and the exit aperture. Each nozzle body is connected to a first end of a corresponding nozzle tube with each nozzle body forming an internal cavity and a plurality of fastener receiving slots. The nozzle tube extends along a nozzle axis, wherein the nozzle axis intersects a nozzle body axis, forming a nozzle angle between the axes. 
     In operation, the nozzle body and accompanying nozzle tube are positioned adjacent to a fluid emitting base, preferably with the nozzle tube projecting away from the fluid emitting base. Fluid exiting the fluid emitting base is received through the nozzle body cavity, enters the fluid inlet of the nozzle tube, moves through the nozzle passageway formed by the nozzle tube, and exits through the fluid exit aperture of the nozzle tube. 
     Each nozzle tube can direct fluid in a plurality of directions. In general, the direction of fluid exiting the fluid exit aperture of each nozzle tube is reversed from a first direction to a second direction by removing fasteners that removably connect each nozzle body and corresponding nozzle tube to the fluid emitting base, reversing the fluid exit aperture of each nozzle tube from a first direction to a second direction by rotating the nozzle body with respect to the fluid emitting base, aligning fastener receiving slots formed by each nozzle body with fastener receiving holes formed by the fluid emitting base, and reinstalling the fasteners through the fastener receiving slots formed by the nozzle body and the fastener receiving holes formed by the fluid emitting base. Removal of the nozzles for maintenance or replacement in similar, except that once the fasteners are removed, the old nozzle is removed, and the new nozzle is installed as indicated above. 
     These and other advantages of the present invention will be clarified in the Detailed Description of the Preferred Embodiments taken together with the attached drawings in which like reference numerals represent like elements throughout. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top perspective view of a first embodiment of a reversible nozzle made in accordance with the present invention; 
     FIG. 2 is a cross-sectional perspective view of the reversible nozzle shown in FIG. 1; 
     FIG. 3 is a top perspective view of a second embodiment of a reversible nozzle made in accordance with the present invention; 
     FIG. 4 is an exploded view of the nozzle shown in FIG. 1 and a portion of a turbine casing, with the nozzle in a first orientation; and 
     FIG. 5 is an exploded view of the nozzle and turbine casing shown in FIG. 4 with the nozzle in a second orientation. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a nozzle  10  made in accordance with the present invention. The nozzle  10  generally includes a nozzle tube  12  and a nozzle body  16 , and is preferably made from metal, such as stainless steel. 
     As shown in FIG. 2, the nozzle tube  12  defines a first end  17 , a fluid exit aperture  15 , and a nozzle passageway  14  connecting the first end  17  and the fluid exit aperture  15 . The nozzle tube  12  shown in FIG. 1 is non-cylindrical, allowing the nozzle  10  to be used in applications where higher fluid velocities are desired. The non-cylindrical shape causes divergence of the passing fluid, thereby causing the fluid velocity to increase. It is noted, however, that nozzle tube  12  can assume any suitable configuration or shape. 
     The nozzle body  16  is connected to the first end  17  of the nozzle tube  12 . The nozzle body  16  defines an internal cavity  19  and forms a plurality of fastener receiving slots  18 ,  18   a  with at least one fastener receiving slot  18   a  having an elongated shape. Slots  18  are circular in shape and are adapted to receive a fastener  34 . Slot  18   a  is somewhat elliptical in shape and is adapted to receive the same diameter fastener  34 . Preferably, the length L of the elongated slot  18   a  is approximately two times larger than the width D, which is the same as the diameter D of slots  18 . The elongated slot  18   a  permits reorienting the nozzle  10  in two directions with only three slots  18 ,  18   a , as will be discussed below. In the nozzle  10  shown in FIG. 1, three fastener receiving slots  18 ,  18   a  are suitably spaced to allow correct positioning of the nozzle body  16  with respect to a fluid emitting base, such as a half turbine casing  22 , as shown in FIG. 4, for both clockwise and counterclockwise turbine rotation. The nozzle body  16  further defines a lip  21 . 
     With continuing reference to FIG. 1, the nozzle tube  12  extends along a nozzle axis  20  and intersects a nozzle body axis X, forming an angle α. In FIG. 2, the nozzle axis  20  is shown passing longitudinally through a center of the nozzle tube  12 . In FIGS. 1 and 3, the same nozzle axis  20  shown in FIG. 2 is drawn on an exterior surface of the nozzle tube  12  for clarity. However, each of the angles α shown in FIGS. 1-3 are identical to one another in this embodiment. 
     FIG. 3 shows a second embodiment of a nozzle  10 ′ according to the present invention. The nozzle  10 ′ is similar in external appearance to the nozzle  10  shown in FIGS. 1-2; however, the nozzle  10 ′ in the second embodiment has a nozzle tube  12 ′ that is cylindrical in shape, which is useful in lower velocity applications; moreover, the arrangement of the fastener receiving slots  18 ′,  18   a ′ is similar for nozzle  10 ′, but the fastener receiving slots  18 ′,  18   a ′ are recessed with respect to the nozzle body  12 ′, thereby allowing the fastener  34  heads, shown in FIG. 4, to sit below a top surface of the nozzle body  16 ′ and not increase the overall size. of the nozzle  10 ′ when the fasteners  34  are installed. 
     FIGS. 4-5 show a fluid emitting base, such as a half of a steam end casing  22 , that includes an outer flange  24  for receipt of fasteners  34  for connection to a downstream turbine casing. The half turbine casing  22  includes an inner ring  26  machined to receive a plurality of nozzles  10 , of which only one is shown. The inner ring  26  includes a plurality of nozzle receiving recesses  27  and a plurality of threaded fastener receiving holes  28 . The fastener receiving holes  28  are adapted to align with respective fastener receiving slots  18 ,  18   a  defined in the nozzle body  16 . 
     A plurality of passageways  30  and lip receiving recesses  32  are defined in the inner ring  26 . The nozzle  10  is adapted to be received within the respective nozzle receiving recess  27  so that the fastener receiving holes  28  formed by the nozzle body  16  are aligned with respective fastener receiving slots  18 ,  18   a . The lip  21  is received within the lip receiving recess  32  providing a fluid seal. Passageway  30  provides a channel for fluid, such as vaporized water, to exit the half turbine casing  22  and enter the first end  17  of the nozzle tube  12  through fluid inlet  19 . Fasteners  34 , such as ¼-20 bolts, pass through respective fastener receiving holes  28  and fastener receiving slots  18  for securing and sealing the nozzle  10  to the half turbine casing  22 . In this arrangement, all of the nozzle tubes  12  are aligned in a first orientation similar to that shown in FIG. 4, and fluid entering the fluid inlet  19  and exiting the nozzle exit aperture  15  is directed in a first direction, such as a counterclockwise direction, indicated by the arrow. The number of nozzles  10  utilized in a specific turbine is dependent on a number of operating parameters and, therefore, several of the nozzles  10  may not contain passageway  14 . These nozzles  10  are known as blanks. 
     FIG. 5 is similar to FIG. 4 except that each nozzle  10  is rotated an appropriate angle with respect to half turbine casing  22  so that fluid exits the nozzle  10  in a second direction, such as a clockwise direction, as indicated by the arrow. All of the elements in FIG. 5 have the same reference numerals as the elements in FIG.  4 . 
     A method of reversing a direction of fluid flow from a reversible nozzle  10  connected to a fluid emitting base, such as a half turbine casing  22  or a pressure vessel is now described. The same steps apply to each embodiment, but only nozzle  10  will be discussed. 
     The first step is removing fasteners  34  that removably connect the nozzle  10  to the half turbine casing  22 . The next step is reversing the fluid exit aperture  15  of each nozzle tube  12  from a first direction to a second direction by rotating the nozzle body  16  with respect to the half turbine casing  22 . The next step is aligning the fastener receiving slots  18 ,  18   a  formed by said nozzle body  16  with fastener receiving holes  28  formed by the half turbine casing  22 . The final step is reinstalling the fasteners  34  through the fastener receiving slots  18 ,  18   a  formed by the nozzle body  16  and the fastener receiving holes  28  formed by the half turbine casing  22 . 
     The present invention enables the same nozzle  10 ,  10 ′ to direct a fluid, such as water, steam, or gas, in a plurality of directions by orienting the nozzles  10 ,  10 ′ with respect to a fluid emitting base. In turbine applications, the present invention eliminates the need for welding nozzles  10 ,  10 ′ to the half turbine casings  22  and eliminates the need for different nozzles  10 ,  10 ′ to direct fluid in different directions. Further, the present invention eliminates the need of removing worn nozzles  10 ,  10 ′ by machining the half turbine casing  22  because of welded nozzles  10 ,  10 ′. The present invention permits quick removal of the nozzles  10 ,  10 ′ for either repair or change in orientation, by removing the appropriate fasteners  34  and securing the nozzles  10 ,  10 ′ to the half turbine casing  22 . Furthermore, the nozzle tube  12 ,  12 ′ is available in a plurality of converging/diverging passageways  14  to optimize the nozzle  10 ,  10 ′ efficiency for the specified turbine operating conditions. Finally, the present invention eliminates the need to carry different oriented nozzles  10 ,  10 ′ in inventory. 
     The invention has been described with reference to the preferred embodiments. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.