Patent Publication Number: US-2016238009-A1

Title: Enclosed double suction pump

Description:
CROSS REFERENCES 
     This application claims the benefit of U.S. Provisional Application No. 62/125,604, filed on Jan. 26, 2015, which application is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     A preferred embodiment of the invention refers to a pump and, more specifically, to a pump suitable for pumping viscous liquids, slurries, or solids. 
     BACKGROUND 
     Process tanks and pipelines are utilized in a variety of industrial settings to store many different types of liquids. Some liquids may contain a certain amount of solids, heavy oils, or similar heavy materials, which may result in the heavier materials accumulating in the bottom of a tank over a period of time. When the tank is eventually required to be pumped dry for cleaning, inspection, change of service, or other reasons, the material to be pumped out from the bottom of the tank may comprise a thick, viscous slurry or heavy sludge. Such materials may be difficult to remove from the tank because they may damage or clog many conventional types of pumps. Removing all of the material from the tank may require the tank to be vacuumed, which can be an expensive and time-consuming process. In some cases, workers may have to enter the tank, which may expose workers to chemicals and hazardous work conditions. 
     Accordingly, a need exists in the art for a pumping apparatus that can be used to pump any type of liquid or semi-solid material, including viscous slurries or sludge. In addition, a need exists in the art for a pumping apparatus that can be used to pump heavy liquids from a tank in a safe, fast, and cost effective manner. 
     SUMMARY 
     In accordance with the present invention, there is provided a centrifugal pump apparatus that is capable of pumping heavy liquids, sludge, or fluidized solids and that is configured such that the apparatus can be attached to a process tank or to piping used for transferring such materials. The pump has a double suction configuration with dual annular inlet openings. The pump is installed within a sealed chamber having suction and discharge connections. 
     In one aspect, the apparatus comprises a pipe tee and a pump housing mounted within the pipe tee. The pipe tee has an inlet, an outlet, and two ends closed by blind flanges in order to provide the sealed chamber. The pump housing has a discharge outlet and opposing inlet openings on opposite sides of the pump housing. The pump housing discharge outlet is aligned with and extends to the pipe tee outlet so that the flowable material is discharged through the pump housing discharge outlet and out of the pipe tee outlet. The apparatus further comprises an impeller mounted on a driveshaft within and in spaced relationship with the pump housing. Neither the driveshaft nor the impeller come into contact with the pump housing. The impeller has outwardly extending blades for movement of the flowable material outward to the discharge outlet. The driveshaft is mounted within the pipe tee and extends through the opposing inlet openings of the pump housing. The driveshaft further extends through openings in each blind flange, and at least one end of the driveshaft is operatively connected to a motor. The motor is preferably a hydraulic or an electric motor. In a preferred embodiment, dual hydraulic motors are utilized, and each end of the driveshaft is operatively connected to a respective motor. The motors are configured for cooperatively rotating the driveshaft. The apparatus preferably comprises a shaft bearing installed on the exterior of each blind flange for supporting the driveshaft. The apparatus is free of internal bearings, mechanical seals, or wear plates. 
     Preferably, the pipe tee inlet has a flanged end so that the pipe tee can be attached to a flanged outlet on the sidewall of a tank or on the bottom of an elevated tank. In one embodiment, a valve is installed between the tank and pipe tee. To pump material out of the tank, the valve is opened and the fluid fills the pipe tee. The motors are then activated to begin pumping. Fluid enters the pump housing through both inlet openings so that the pressure on the impeller is approximately equal on both sides. The double-suction impeller acts as a strong fan that can pull a vacuum, self-prime, and begin pumping. The pump is capable of pumping a variety of heavy fluids including, but not limited to slurries, sludge, and fluidized abrasive solids such as oilfield drill cuttings, drilling cement, crude oil, and mud slurry. The pump is also capable of running wet or dry and pumping in forward or reverse. 
     In another embodiment, the pipe tee inlet and outlet both have flanged ends, which are connected in-line to a pipe having flanged connections to be used as an in-line booster pump. 
     In another embodiment, the double suction pump can be installed inside a sealed chamber made from a welded box or similar type of enclosure. The box has a flanged inlet and outlet for connection to a tank or pipe. The driveshaft extends through openings in opposing sides of the box, and at least one end of the driveshaft is operatively connected to a motor. Single or dual hydraulic or electric motors may be utilized. 
     Accordingly, one object of the present invention is to provide a pumping apparatus that can be used to pump any type of liquid or semi-solid material, including viscous slurries, sludge, or fluidized abrasive solids. 
     Another object of the present invention is to provide a pumping apparatus that dual motors configured for cooperatively rotating a driveshaft. 
     Another object of the present invention is to provide a pumping apparatus that is free of internal bearings, mechanical seals, or wear plates. 
     Another object of the present invention is to provide a pumping apparatus that is self-priming. 
     Another object of the present invention is to provide a pumping apparatus that can be used to pump heavy liquids from a tank in a safe, fast, and cost effective manner. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
         FIG. 1  shows a perspective view of a pump in accordance with the present invention. 
         FIG. 2  shows a side elevational view of a pump in accordance with the present invention. 
         FIG. 3  shows a perspective view of a pump in accordance with the present invention. 
         FIG. 4  shows a side elevational view of a pump in accordance with the present invention. 
         FIG. 5  shows an exploded view of a pump housing in accordance with the present invention. 
         FIG. 6  shows a side elevational view of an impeller in accordance with the present invention. 
         FIG. 7A  shows a perspective view of an installed pump in accordance with the present invention. 
         FIG. 7B  shows a perspective view of an installed pump in accordance with the present invention. 
         FIG. 8  shows a perspective view of a pump in accordance with the present invention. 
         FIG. 9  shows a perspective view of a pump in accordance with the present invention. 
         FIG. 10  shows a side elevational view of a pump in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the Summary above and in this Detailed Description, and the claims below, and in the accompanying drawings, reference is made to particular features, including method steps, of the invention. It is to be understood that the disclosure of the invention in this specification includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect or embodiment of the invention, or a particular claim, that feature can also be used, to the extent possible, in combination with/or in the context of other particular aspects of the embodiments of the invention, and in the invention generally. 
     The term “comprises” and grammatical equivalents thereof are used herein to mean that other components, ingredients, steps, etc. are optionally present. For example, an article “comprising” components A, B, and C can contain only components A, B, and C, or can contain not only components A, B, and C, but also one or more other components. 
     Where reference is made herein to a method comprising two or more defined steps, the defined steps can be carried out in any order or simultaneously (except where the context excludes that possibility), and the method can include one or more other steps which are carried out before any of the defined steps, between two of the defined steps, or after all the defined steps (except where the context excludes that possibility). 
     Turning now to the drawings,  FIGS. 1-2  show a preferred embodiment of the present invention. In one aspect, a pump apparatus comprises a pump housing  18  disposed within a pipe tee  10 . The pump housing  18  is mounted inside the pipe tee  10  by bolting the housing  18  to a mounting bar  24  attached to the interior of the pipe tee  10 . As best seen in  FIG. 1 , the pipe tee  10  has an inlet  12 , an outlet  14 , and two closed ends  16 . In a preferred embodiment, the ends have flanges with blind flanges  16  installed thereon. The pump housing  18  is preferably equidistant from each blind flange  16  and aligned with the pipe tee inlet  12  and outlet  14 . The blind flanges  16  are installed on the ends of the pipe tee  10  to provide a sealed chamber in which the pump housing  18  is mounted. 
       FIG. 5  shows an exploded view of the pump housing  18  mounted within the pipe tee  10  in accordance with one embodiment of the present invention. Preferably, the pump housing  18  is a split housing comprising an upper housing  18   a  and a lower housing  18   b  that are bolted or otherwise fastened together to form the pump housing  18 . The upper housing  18   a  has a discharge outlet  20 . As best seen in  FIG. 2 , the discharge outlet  20  is aligned with and extends outward to the pipe tee outlet  14  so that flowable material is discharged through the pump housing discharge outlet  20  and out of the pipe tee outlet  14 . The lower housing  18   b  has a drainage port  54  for draining the housing  18  for maintenance. 
     An impeller  40  is mounted on a driveshaft  26  within the pump housing  18  and in spaced relationship with the pump housing  18  such that neither the impeller  40  nor the driveshaft  26  comes into contact the pump housing  18 . In a preferred embodiment, the impeller  40  has a clearance of about 3/16 to about ¼ inch from the pump housing  18 . The assembled pump housing  18  has opposing inlet openings  22  on each side of the housing  18 , as shown in  FIG. 5 . The location of the inlet openings  22  in the complete pump apparatus can also be seen in  FIGS. 2 and 4 . The annular inlet openings  22  allow flowable material to be sucked into the pump housing  18  through the openings  22  and pumped out of the discharge outlet  20 . 
       FIG. 6  shows a preferred embodiment of an impeller  40  utilized with the present invention. The impeller  40  has outwardly extending blades  42  for movement of flowable material outward to the discharge outlet  20 . The blades  42  preferably diminish in thickness as they extend outward. The blades  42  are preferably straight but may alternatively be curved. In one embodiment, the impeller  40  is made from two halves,  50   a  and  50   b , which may be welded together along line  48 . In another embodiment, the two-piece impeller  40  may be bolted together for a compression fit to the drive shaft  26 . The impeller  40  is provided with an opening or channel  46 , which may be keyed for use with the driveshaft  26 . Both sides of the impeller  40  have a sloped surface  44  and a flat portion  52 , which is formed as a result of grinding or shearing so as to balance the impeller. The blades  42  are attached to the sloped surface  44 . Preferably, the sloped surface  44  of the impeller  40  has a slope of about 30 to about 45 degrees. The sloped surfaces  44  on each side of the impeller  40  moves flowable material outward toward the blades  42  for discharge through the discharge outlet  20 . 
     The driveshaft  26  is mounted within the pipe tee  10  and connected to a motor  28  configured for rotating the driveshaft  26 . As best seen in  FIGS. 2 and 5 , the driveshaft  26  extends through both of the opposing inlet openings  22  of the pump housing  18  in a spaced, non-contacting relationship to the pump housing  18 . In a preferred embodiment, each blind flange  16  has an opening therethrough and the driveshaft  26  further extends through each of the openings in the blind flanges  16  for connection to a motor  28  located outside the sealed chamber of the pipe tee  10 . 
     At least one end of the driveshaft  26  is connected to a motor  28  configured for rotating the driveshaft  26 . In preferred embodiment, the motor  28  is a hydraulic motor or an electric motor, though any motor suitable for rotating the driveshaft  26  may be utilized. In an alternative embodiment, the motor  28  may be powered by a direct drive shaft from an engine.  FIGS. 1-2  show a preferred embodiment utilizing two hydraulic motors  28 . The hydraulic motors  28  are attached to the exterior of the blind flanges  16  by a bracket  34 . The driveshaft  26  is connected to each hydraulic motor  28  via a coupling  32 . Hoses for hydraulic fluid (not shown) can be attached to fluid connection ports  30  for driving the motor  28 . The two hydraulic motors  28  are configured for cooperatively rotating the driveshaft  26 . 
     The driveshaft  26  has either spline shaft connections or keyed couplings, depending on the type of drive motor  28  utilized with the apparatus. For electric motors, a coupling or a male spline shaft can be inserted into a female spline that is built into the electric motor, which may eliminate the need for a coupling. For hydraulic drive motors, a keyed coupling  32  is installed between the hydraulic motor  28  and the driveshaft  26 . The hydraulic motors may be powered by a hydraulic power unit (HPU). 
     As shown in  FIGS. 1-2 , the pump apparatus further comprises shaft bearings  36  for supporting the driveshaft  26  and maintaining proper alignment of the driveshaft  26  and impeller  40 . A shaft bearing  36  is attached to each respective blind flange  16 . In a preferred embodiment, as best seen in  FIG. 1 , each shaft bearing  36  has a flange mount and is installed on the exterior of each respective blind flange  16  such that no shaft bearings are located inside the pipe tee chamber. Lubricators can be installed to lubricate the external shaft bearings  36  to further enhance the low-maintenance aspect of the apparatus. In one embodiment, the use of dual hydraulic motors  28  eliminates the need for shaft bearings  36 , though shaft bearings are preferred on the exterior of the pipe tee in order to provide added support for the driveshaft  26 . Driveshaft penetrations through the openings in the blind flanges  16  have rotary shaft pressure seals installed between the driveshaft  26  and each blind flange  16  in order to form a sealed chamber and maintain pressure inside the pipe tee  10  during operation of the pump. The internal pumping chamber formed inside the tee  10  is free of bearings, mechanical seals, and wear plates. 
     As shown in  FIGS. 1-2 , the pipe tee inlet  12  and the outlet  14  each preferably has a flange. All flanges are preferably in compliance with ASME flange standards. The flanged inlet  12  provides a simple mechanism for quickly and easily installing the pump apparatus to a process tank  56  by bolting the inlet flange  12  to a flanged outlet on the tank  56 , as shown in  FIG. 7A . In a preferred embodiment, as shown in  FIG. 7B , a valve  58  is positioned between the pipe tee  10  and the outlet of the tank  56 . The valve  58  allows an operator to isolate the pipe tee  10  from the tank  56  by closing the valve  58 .  FIGS. 7A and 7B  show the pump apparatus attached to the side wall of a tank  56 , though the apparatus may also be attached to the bottom of an elevated tank. To pump material out of the tank  56 , the valve  58  is opened and the fluid fills the sealed cavity in the pipe tee  10  where the pump housing  18  is mounted. The motors  28  are then activated to begin pumping. Fluid fills the pipe tee  10  and is sucked into the pump housing  18  through both inlet openings  22  so that the pressure on the impeller  40  is approximately equal on both sides of the impeller  40 . The impeller  40  discharges the fluid from the pipe tee outlet  14 . A hose  60  is preferably attached to the flanged outlet  14  for transferring the fluid, though hard piping may also be connected to the flanged outlet  14 . In an alternative embodiment, the pipe tee inlet  12  and outlet  14  may have welded connections so that the inlet and outlet can be welded to existing piping. 
       FIGS. 3-4  show an alternative embodiment of the pump apparatus utilizing an electric motor for rotating the driveshaft  26 . This embodiment preferably utilizes only one motor  28 . This embodiment further comprises two shaft bearings  36 , as discussed in the previous embodiment. The end of the driveshaft  26  opposite the motor  28  has a flange-mounted shaft bearing  36  attached to the exterior of a blind flange  16  to support the distal end of the driveshaft  26 . A second shaft bearing  36  is attached to the exterior of the blind flange  16  adjacent to the motor  28 . This embodiment is typically utilized in permanent installations of the pump apparatus. The embodiment shown in  FIGS. 1-2  is preferred for mobile applications in which the pump apparatus is transported between multiple locations and attached to existing tanks or other piping. 
     In an alternative embodiment, as shown in  FIG. 8 , the pump apparatus as shown in  FIG. 1  can be connected to a process pipe to be used as a booster pump. In this embodiment, a flanged pipe  62  used for conveying fluid is connected to both the inlet flange  12  and the outlet flange  14  of the pipe tee  10  to form an in-line booster pump for increasing the pressure and flow rate of the fluid. 
       FIGS. 9-10  illustrate an alternative embodiment of the present invention. In this embodiment, a box  70  forms a sealed chamber in which the pump housing  18  is mounted. The box  70  has a top, a bottom, and four sides, which may be welded together, bolted together, or otherwise attached by any method suitable for providing a sealed, pressurized chamber. The box  70  has an inlet  12  and an outlet  14 . The inlet  12  and the outlet  14  are both configured for attaching to a means for conveying or storing fluid, such as a pipe or a tank. In a preferred embodiment, the inlet  12  and the outlet  14  each preferably has a flange such that both the inlet  12  and the outlet  14  can be connected to a flanged outlet on a tank or to a flanged end of a pipe. As shown in  FIG. 10 , the pump housing  18  is mounted inside the box  70  in the same manner as in the pipe tee  10  embodiment. The driveshaft  26  extends through the opposing inlet openings of the pump housing  18  in a spaced, non-contacting relationship to the pump housing  18 . The driveshaft  26  further extends through openings in opposing sides of the box  70 , and at least one end of the driveshaft  26  is operatively connected to a motor. This embodiment preferably utilizes a single electric motor, though single or dual hydraulic or electric motors may alternatively be utilized. The end of the driveshaft  26  opposite the motor has a flange-mounted shaft bearing  36  attached to the exterior of a blind flange  16  to support the distal end of the driveshaft  26 . A second external shaft bearing  36  is located on the side of the box  70  adjacent to the motor. 
     The pump apparatus of the present invention provides a number of advantages over other pump designs. The double-suction impeller  40  design of the pump apparatus functions as a strong fan that can pull a vacuum, self-prime, and begin pumping. The pump can run wet or dry and pump in forward or reverse without damaging the pump. Unlike other centrifugal pumps, the pump can run dry for an extended period of time without causing damage to the pump. The pump is capable of pumping a variety of heavy fluids including, but not limited to slurries, sludge, and fluidized abrasive solids such as oilfield drill cuttings, drilling cement, and mud slurry. The double-sided impeller  40  does not have tight tolerances, which allows passage of abrasive solids with a minimal amount of erosional wear, which makes the pump of the present invention particularly effective in abrasive applications such as drill cuttings. The pump can also be quickly and easily attached to a process tank or to piping used for transferring such materials. 
     The double-suction impeller  40  design also eliminates thrust loading of the impeller by eliminating the differential pressure across the impeller. The pressure is equal on both sides of the impeller because the impeller is pulling flow from both sides. The equalized pressure eliminates the need for mechanical seals and wear plates, and consequently this centrifugal pump has no internal friction. Unlike other centrifugal pumps, the shaft bearings are not subjected to the usual wear that occurs during the pumping process since the shaft bearings are located outside the sealed pumping chamber. Because the pump of the present invention does not have internal bearings, seals, or wear plates, the pump is ideally suited for use in the food processing industry. There are no parts of the pump apparatus located inside the sealed pumping chamber that require lubrication or internal maintenance. The impeller  40 , pump housing  18 , and driveshaft  26 , along with the internal walls of the sealed chamber can be sterilized and would not require frequent maintenance thereafter. The pump can be used for pumping food products such as milk, mayonnaise, ketchup, or drinks without affecting the quality of the food. Because the internal parts inside the sealed pumping chamber do not require lubrication, the risk of contamination of the food from lubricating mechanical seals and wear plates is virtually eliminated. In addition, the lack of internal mechanical seals, bearings, and wear plates virtually eliminates the risk of metal contamination entering the food process stream. 
     The pipe tee  10  materials of construction may include casted ductile iron, welded steel, composite plastic, fiberglass molded, or any other suitable material known in the art. 
     It is understood that versions of the invention may come in different forms and embodiments. Additionally, it is understood that one of skill in the art would appreciate these various forms and embodiments as falling within the scope of the invention as disclosed herein.