Abstract:
A valve assembly for a liquid containing tank or the like, having a vortex breaker within the tank of liquid, and affixed to an external valve. The valve has a discharge port and a valve body with an outer member which allows the flow of liquid and a concentrically-spaced inner member provided with upper and lower seals to prevent the leakage of the liquid and allow uniform closure of the valve. The inner tubular member is movable vertically such as with a screw thread and associated handle, from a closed to an open position to allow flow of the liquid from the tank to a discharge port.

Description:
BACKGROUND 
   This invention relates to a discharge valve assembly for a tank or the like containing a liquid and more particularly to such a valve having a vortex breaker for maintaining uniform flow. 
   Tanks or other constructions for containing liquids are widely used in the pharmaceutical and bio-technology field which require methods and apparatus for ease of cleaning, and for removing at least a portion of the liquid in a uniform and rapid manner. Most valves for tanks are constructed to obtain maximum flow of the liquid being discharged in a minimum amount of time and are not concerned with uniform flow. 
   U.S. Pat. No. 4,013,096 which issued on Mar. 22, 1977 and U.S. Pat. No. 4,126,294 which issued on Nov. 21, 1978, both to Joseph H. DeFrees; U.S. Pat. No. 5,341,523 issued Aug. 30, 1994 to Steven R. Barnes; and U.S. Pat. No. 4,518,149 which issued on May 21, 1985 to John F. Gardner, generally disclose a combination of vortex breakers and valves for tanks. 
   U.S. Pat. No. 4,905,963 issued on Mar. 6, 1990 to Dwight E. Nichols discloses a sliding gate tank valve assembly in which fluid pressure on the gate is at right angles to the direction of flow for purposes of breaking the formation of a vortex. 
   U.S. Pat. No. 3,828,819 which issued on Aug. 13, 1974 to Erik E. Brogren discloses vanes which serve as a vortex breaker and U.S. Pat. No. 4,836,236 which issued to Thomas P. Ladisch is directed to a flush sealing tank valve. 
   SUMMARY OF AN EMBODIMENT OF THE INVENTION 
   It is an object of the invention to provide a combination value which contains a vortex breaker and a simplified shut off. 
   It is another object of the invention to provide a valve for a liquid container with reduced field welding and finishing and also reduced associated labor costs and time of manufacturer. 
   It is a further object of the invention to provide a valve with reduced flow losses. 
   It is still another object of the invention to provide a valve to maintain fluid contact and correct fluid velocity with minimized air entrapment. 
   It is still another object of the invention to provide a valve assembly which is readily cleanable allowing its use in pharmaceutical and bio-technical operations. 
   It is a further object of the present invention to provide a compact discharge valve without reducing efficiency. 
   It is still a further object of the invention to provide a valve capable of positive sealing to prevent leakage in both the open and closed valve positions. 
   Another object of the invention is to provide a discharge valve which is easy to operate. 
   A still further object of the invention is to provide a valve assembly for a tank or the like which permits a large volume discharge rate flow without vortices in the throat of the discharge opening which interferes with the discharge. 
   It is a further objective of the invention to provide a discharge valve for a tank which permits a large volume discharge rate without formation of vortices of second liquid phase, such as oil and water, where the second phase, such as oil, will tend not to be easily entrained in the first fluid, such as water, thereby allowing for a better phase separation. 
   In accordance with one embodiment of the invention a valve assembly is provided for the discharge of liquid from a tank or the like which includes a novel vortex breaker and a valve for controlling the flow of liquid to a lower located discharge port. The vortex breaker is positioned at an opening in the tank to allow removal of the liquid from the tank to flow in a smooth flow. The configuration of the invention allows the utilization of a valve of smaller dimension than normally required to obtain the same flow. A traditional vortex breaker is a flat, circular disk, supported off the bottom of the vessel by welded tabs provided by the vessel supplier. 
   In accordance with the invention, a vortex breaker is provided which is a complex disk formed by a generally convex-shaped leg supported off the bottom of the vessel by a connecting member to the lower leg contoured to promote streamlined flow of the tank&#39;s fluid as it passes the member and leaves the vessel through the integrated valve associated with the vortex breaker. The upper portion or leg of the convex vortex breaker disk directs liquid flow to the lower edges of the disk, thereby preventing the pooling of liquid on top of the disk and making it more easily cleaned by the flowing fluid in the vessel. The lower portion of the convex vortex breaker or lower leg forms a streamlined flow path between the bottom of the vessel and the integrated shut-off valve where the departing fluid is uniformly accelerated into the throat of the discharge passageway. 
   A conduit such as a tube, is affixed to the discharge passageway extends from the lower portion of the tank directly below the vortex breaker to allow flow of the liquid out of the container to a lower positioned discharge port. A valve is provided at the lower discharge port to control the flow of liquid. The discharge port is affixed to the vertical conduit at a desired location which is preferably sloping downward at an angle to allow the even flow of the liquid. The shut-off valve can be a solid metal, cylindrical member located within the conduit tube which is moveable vertically within the conduit to open and close off the flow of liquid to the lower discharge port. 
   It is preferred that upper and lower “O” ring seals are provided around the solid member which bracket the lower discharge port to prevent the passage of liquid around the solid cylindrical member in the tube. Additional seals can be provided, such as Teflon sleeves or washers, to further assure that no liquid is lost. 
   Means are provided for moving the solid member from a position of preventing the flow of liquid from the container to the discharge port and a second, lower position which allows flow of the liquid from the container to the discharge port. The solid member can have an actuation shaft extension which is threaded at its lower end. The threaded portion meshes with a collar of similar threads which when rotated will cause the solid member to move upward into a closed position and when reversed moves downward to open the valve and allow the flow of the liquid from the tank to the lower discharge port. 
   Further objects, features and the advantages of the invention will become evident from a consideration of the following detailed description when taken in conjunction with the accompanying drawings and the appended claims. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a cross-sectional view of a tank and valve assembly in the closed position according to the present invention; 
       FIG. 2  is a cross-sectional view of a tank and valve assembly in an open position in accordance with the present invention; and 
       FIG. 3  is an isometric view of the valve assembly according to the present invention. 
   

   DETAILED DESCRIPTION 
   In accordance with the invention with reference to  FIGS. 1 ,  2  and  3  of the drawings, a tank  10  for liquid storage or transport has a valve assembly generally indicated at  12 . In the configuration shown in  FIG. 1  the valve is in the closed position. In  FIG. 2  the valve is shown in the open position. 
   The tank  10  is provided with a vortex breaker generally indicated at  14  which can be welded  16  or adhesively secured in place or otherwise affixed at the bottom of the tank  10  in an opening  11 . The tank bottom surface can be dished, spherical or conical, based on the tank design. The vortex breaker  14  comprises an upper leg element  18  and a lower leg element  20  which are in the form of concentric disks. The two elements  18 ,  20  are affixed with contoured connecting element  24  along only a portion of the elements  18 ,  20  to allow structural strength while permitting sufficient area generally indicated at  32  for the liquid to flow from the tank  10  between the legs  18 ,  20 . The upper leg  18  has a convex upper surface  26  yielding a gradual sloped surface  28 . The underside  30  of the upper disk  18  is also convex forming a greater thickness at the center of the upper leg  18  with gradual sloping sides extending from the center. A slope of between 5 to 30 degrees from the horizontal is preferred. The lower leg  20  has a substantially greater diameter than the upper leg, creating the flow area for the liquid generally indicated at  32 . The upper surface  34  of the lower leg  20  conforms with the lower surface  30  of the upper leg so the passage for the liquid between the legs is generally uniformly accelerating as it approaches the valve passageway  22 . The passageway  32  in the lower leg  20  has a smooth radius  31  on the leg to promote uniform flow of the liquid. The lower leg  20  has a centrally located opening or passageway  22  for the passage of the liquid to the valve which controls the flow of liquid. The passageway  22  is connected to a tube  40  through which the liquid flows. 
   The diameter of the top leg of the vortex breaker is preferably about four times the inlet tube diameter with a range of about two to about six times being useful. The gap between the tank bottom and the upper leg of the vortex breaker is preferably one-quarter to one-half the diameter of the inside dimension of the tubing inlet for the valve. One of the important advantages of the invention is that use of the vortex breaker of the invention enables the substantial reduction in the size of valve required with the corresponding reduction in cost of the valve assembly. As indicated, the best results are obtained with a slope of the surface of the bottom leg of about 5 to about 30 degrees from the horizontal. 
   The valve assembly  12  is affixed to the vortex breaker at the passageway  22  and provides a vertical, hollow cylindrical tube  40  extending downward from the passageway  22  for allowing the liquid to flow from the passageway  22  in the lower leg  20  to a discharge port  42  through the mouth or opening  41 . A suitable discharge port would be an inclined tube  43  leading to a tri-clamp end fitting  44 . A solid closure element  45  concentrically located within the hollow cylinder tube  40  moves in a vertically direction forming a seal on the entrance or opening  41  to outlet port  42  when in an upper position as show in FIG.  1 . When in a lower open position as shown in  FIG. 2 , the liquid flows from the tank  10  to the discharge port  42 . 
   O-rings  46 ,  47  are provided around the solid closing member  45  for a positive seal between the closing member  45  and the tubular member  40 . The O-rings are located to provide positive seating and sealing of discharge port  42  when the closure member  46  is fully inserted in the closed position. The sealing effect of the O-rings can be supplemented by additions washers such as formed from Teflon sleeve  39  and a secondary seal  49 . 
   The valve assembly  12  may be secured within a tank opening in any manner. For example, the valve body may be integrally molded into the tank wall. Alternatively, the assembly  14  could be made of metal and welded  16  in place on a metal tank discharge opening  11 . 
   Means are provided for moving the solid member from a position of preventing the flow of liquid as shown in  FIG. 1  to an open position as shown in  FIG. 2  which allows the fluid to flow to the discharge port  42 . A useful means for accomplishing this movement is by having an actuation shaft extension  60  on the closure element  45  which is threaded  62  at its lower end  64 . The threaded portion  62  meshes with a collar  66  of similar threads which when rotated by a suitable crank and handle  68  will cause the solid member  46  to move into a closed position as shown in FIG.  1  and when reversed moves downward to open the valve as shown in FIG.  2  and allow the flow of the liquid from the tank  10  to the discharge port  42  through opening  41 . 
   The preferred valve is a one inch valve utilizing a one inch outside diameter tube which has an inside diameter of seven-eighths of an inch. Valves from one-half inch up to about eight inches can be utilized with the vortex breaker of the invention which has an emptying capability as if a one-and-one-half inch to a thirty-two inch valve were utilized. 
   In operation, the operating handle  68  is revolved in a counter-clockwise direction which causes the closure element  45  to move downward to open the valve. The rotation is continued until the closure element is completely open with the O-rings  46 ,  47  passing the discharge opening  41  of the discharge port  42 . The opening of the closure element will allow the liquid to flow from the tank  10  through the opening or passageway  32  between the upper leg  18  and the lower leg  20  in a uniformly accelerating flow because of the actions of the vortex breaker  14 . In this manner, the liquid is uniformly accelerated from a slow velocity within the tank to a high velocity inside tube  40  while minimizing air entrapment. 
   Although the invention has been described utilizing a ram style valve which is preferred, the vortex breaker of the invention can also be utilized with other valves, such as a diaphragm valve, a radial diaphragm valve, a ball valve, a butterfly valve, a plug valve and the like. 
   The invention has been described above in an illustrative manner and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather then that of limitation. Obviously many modifications and variations of the valve assembly according to the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.