Patent Publication Number: US-9897099-B1

Title: Impeller for liquid sealed pump

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. Non-Provisional patent application Ser. No. 14/018,854 filed Sep. 5, 2013, which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/743,883 filed Sep. 12, 2012, the entireties of which are hereby incorporated herein by reference for all purposes. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to the field of pumps, and more particularly to liquid sealed pumps and an improved impeller to be used therewith. 
     BACKGROUND 
     Pumps generally require shaft packing or mechanical seals to ensure the fluid to be pumped does not harm or cause catastrophic damage to the pump motor, or to ensure the fluid does not leak therefrom. In some cases, a liquid seal can be used instead of shaft packing or mechanical seals, which is much more economical and requires little to no maintenance. U.S. Pat. No. 4,772,183 to Durden, which is incorporated herein by reference, described using a liquid seal that relies on a vacuum in the extension or support tube to keep tube clear of oil or fluid and prevent flooding of motor or motor bearings. It has now been discovered that a potential disadvantage of such a pump is that the vacuum may be lost due to vapor from the liquids forming in the extension tube. In such an event, vapor may open the relief valve at the top of the extension tube allowing flooding of the tube and motor bearings. 
     Accordingly, it can be seen that needs exist for an improved pump. It is to the provision of a liquid sealed pump with dynamic turbo tech impeller meeting these and other needs that the present invention is primarily directed. 
     SUMMARY 
     In example embodiments, the present invention provides a pump for pumping a fluid. The pump preferably includes a motor, a drive shaft, an impeller, a pump housing that includes an inlet portion and an outlet portion, and an extension tube extending between the motor and the pump housing. Preferably, a portion of the fluid to be pumped is contained within the extension tube at a relatively constant level to provide a seal. 
     In another aspect, the invention relates to a liquid sealed pump preferably including an impeller, a shaft coupled to the impeller for rotationally driving the impeller, a shaft sleeve at least partially surrounding the shaft and allowing rotation of the shaft therein, an extension tube at least partially surrounding the shaft sleeve and defining an annular fluid containment chamber between the extension tube and the shaft sleeve, a sealing fluid supply conduit for delivering a sealing fluid to the annular fluid containment chamber at a first elevation, and a sealing fluid return conduit for discharging the sealing fluid from the annular fluid containment chamber at a second elevation. The shaft sleeve preferably includes at least one relief hole allowing fluid flow therethrough, and a sealing fluid level is maintained in the annular fluid containment chamber between the first elevation and the second elevation. 
     In another aspect, the invention relates to a pump impeller for a liquid sealed pump. The impeller preferably includes an extended snout defining a bearing surface, and a plurality of semi open face impeller vanes. 
     These and other aspects, features and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description of the invention are exemplary and explanatory of preferred embodiments of the invention, and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial cutaway view of an impeller according to an example embodiment of the present invention. 
         FIG. 2  is a top view of the impeller of  FIG. 1 . 
         FIG. 3  is a side view of the impeller of  FIG. 1 . 
         FIG. 4  is a partial side elevation view of a pump assembly according to an example embodiment of the present invention. 
         FIG. 5  is a partial side elevation view of the pump assembly of  FIG. 4 . 
         FIG. 6  is a side elevation view of a pump according to another example embodiment of the present invention. 
         FIG. 7  is a side elevation view of a pump according to yet another example embodiment of the present invention. 
         FIG. 8  is a side elevation view of a pump according to another example embodiment of the present invention, wherein the impeller is oriented in an inverted manner. 
         FIG. 9  is a side elevation view of a pump according to another example embodiment of the present invention, wherein the impeller is inverted in an inverted manner. 
         FIG. 10  is a partial side elevation view of a pump according to another example embodiment of the present invention, wherein the pump comprises dual impellers. 
         FIG. 11  is a partial side elevation view of the pump of  FIG. 10 . 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     The present invention may be understood more readily by reference to the following detailed description of the invention taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention. Any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein. 
     Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. 
     With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views,  FIGS. 1-5  show both an impeller  10  and a pump  100  having the impeller  10  rotatably mounted thereto according to an example embodiment of the present invention. In some example forms, the pump  100  is generally constructed similarly to the pump disclosed in U.S. Issued U.S. Pat. No. 4,772,183, the entirety of which is incorporated herein by reference. In one example form, the pump  100  includes a motor M (see  FIGS. 6-7 and 9 ), an extension tube  112  extending from the motor M to a pump housing  116  (comprising an input portion  120 , an output portion  122 , and a central centrifugal area), a drive shaft  126  extending from the motor M to the impeller  10 , a sleeve  130  centrally spaced within the extension tube  112  (and providing an area therein for extension of the drive shaft  126  therethrough), a ring  132  mounted to a top portion of the sleeve  130 , a skirt  134  fixedly mounted to an end of the sleeve  130 , a runner  136  fixedly mounted to an end of the drive shaft  126 , a pump inlet hose  140  for inputting a fluid, an outlet hose  142  for outputting a fluid, and a suction return hose  144 . A labyrinth seal is formed by the skirt  134  and the runner  136 . Preferably, the pump  100  is configured to be liquid sealed, thus no shaft packing or mechanical seal is required for operation. 
     The impeller  10  is generally referred to herein as a dynamic turbo tech impeller, which produces a highly efficient flow of fluid or oil compared to standard enclosed or open face impellers. The impeller  10  generally comprises vanes  12 , a base  14 , a snout portion  20 , and a hub  30 . Preferably, the impeller  10  comprises a semi-open face that comprises the extended snout  20  working as a bearing surface  26 , and a vortex suction generator for pump inlet  120 . Two wiper vanes  16  are formed on the base  14 . The snout portion  20  generally comprises a base  22  and an extension  24 . Preferably, the extension comprises the bearing surface  26 . The hub  30  (generally opposite the snout portion  20 ) generally comprises a centrally-positioned threaded aperture  32  and a bearing surface  34 . Preferably, the close tolerances of the bearing surfaces  26 ,  34  and the impeller vanes  12  provide a highly efficient pump. For example, as depicted in  FIGS. 4-5 , the impeller  10  is preferably sized so that the bearing surfaces  26 ,  34  of the snout  20  and hub  30 , respectively, maintain a clearance of about 0.002″ inches relative to the pump housing  116  and the transverse flange  114 . Additionally, in example embodiments the wiper vanes  16  generally maintain a clearance of about 0.005″ inches relative to an internal portion of the pump housing  116  (e.g., a surface of the central centrifugal area). In one form, the wiper vanes  16  are advantageous to overall performance of the pump through their ability to assist in keeping contaminants from entering or coming close to the bearing surface  34  of the impeller  10 . Further, in example forms, the pump  100  is highly efficient due to ninety percent of impeller vanes  12  being open face and having a clearance of about 0.005″ relative to the pump housing  116 . Preferably, the curvature of the vanes  12  and diameter of the impeller  10  (in addition to the rotational velocity of the drive shaft  126 ) determine the capability of the flow rate of the liquid that is to be pumped. 
     The snout  20  is mounted on the open face vanes  12  by a casting process in producing the impeller  10 , or the snout  20  and base  22  can be welded to the impeller vanes  12 , or can be formed using alternative manufacturing methods. This snout design with the open face impeller vanes will enhance the pumps ability to minimize leakage from pump housing, therefore allowing the impeller to be more efficient. The semi open face vanes allow particles up to ¼″, in small quantities, to pass through the impeller. Particle pass through is important when pumping cooking oil or other fluids contaminated with sediments and particles. Many different bearing materials can be used on the impeller and pump housing to enhance life of the pump. Fluid mediums determine the type bearing materials to be installed on impeller and pump housing. 
     As will be described below, the pump preferably operates to take advantage of the force of gravity and allow the fluid that is being pumped therethrough to act as the seal. The extension tube  112  serves as a vessel to hold a quantity of the fluid therein, which will maintain the seal. Preferably, a separate fill line is communicatively engaged with a portion of the extension tube  112  to ensure that the extension tube  112  maintains a relatively constant fluid level therein. As such, maintaining a relatively constant fluid level within the extension tube  112  prevents other components of the pump from causing the extension tube  112  from becoming dry, which could cause aeration at the pump inlet. 
       FIG. 6  shows a pump  200  according to an example embodiment of the present invention. As depicted, the pump  200  is connected to an oil tank OT for recirculation of the oil or fluid contained therein, for example, similar to hot oil frying tanks. The pump system comprises an inlet hose  140  extending from the oil tank OT to the inlet portion  120  of the pump housing  116 , an outlet hose  142  extending to the outlet portion  122  of the pump housing  116 , a sealing fluid supply hose  210  extending to a lower portion of the extension tube  112 , an excess or overflow sealing fluid return hose  212  extending to an upper portion of the extension tube  112 , and an air vent tube  214  positioned and communicatively engaged proximal the uppermost portion of the extension tube  112 . Preferably, the sleeve  130  comprises one or more weep holes  131  extending therethrough to allow fluid to flow therebetween, for example, fluid that may migrate from the labyrinth seal (skirt  134  and runner  136 ) and up the drive shaft  126 , or fluid flowing in the extension tube  112  from the sealing hose  210 . In the depicted example, six weep holes  131  are provided, in three pairs at sequentially spaced first, second and third elevations or locations along the sleeve  130 . As such, the weep holes  131  ensure that a portion of the shaft sleeve  130  is flooded with oil or sealing fluid. Preferably, the oil or fluid contained within the extension tube  112  (and flooding a portion of the sleeve  130 ) is maintained at a relatively constant level. And by maintaining a relatively constant level of fluid within the extension tube  112 , the fluid preferably also maintains a constant head pressure on the labyrinth seal. Additionally, a bolt  220  can be mounted to a portion of the extension tube  112  (adjacent the ring  132 ) to hold the sleeve  130  down relative to the runner  136  to ensure steam and vapor pressure do not push the sleeve  120  out of position, which could cause losing the liquid seal. Optionally, a filter and/or heat exchanger can be connected to the outlet hose  142  to transfer heat and/or filter particles from the fluid before returning to the oil tank OT. 
       FIG. 7  shows a pump  300  according to another example embodiment of the present invention. As depicted, the pump  300  is generally similar to the pump  200 . Rather than the pump  300  being connected to an oil tank OT, the pump  300  is configured for a direct line connection. In some forms, a direct line connection is used for irrigation, boost, or sump pumps. A sealing hose  310  preferably extends from the outlet hose  142  to a portion of the extension tube  112  wherein a portion of the fluid being output from the pump can be supplied within the extension tube  112  to ensure a relatively constant fluid level therein. An excess sealing return hose  312  is provided at an upper portion of the extension tube  112  to ensure the fluid level does not rise above the ring  132 , and a bolt  320  similarly mounts to the extension tube  112  to hold the sleeve  130  in position. An orifice or valve can be provided in the seal fluid supply line extending from the pump outlet to the seal fluid collection chamber between the pump support tube and the shaft sleeve, to control delivery of oil or other seal fluid through the supply line. One or more hold down bolts can be provided to secure the shaft sleeve to the pump support tube, as shown. 
       FIG. 8  shows a pump  400  according to yet another example embodiment of the present invention. Generally, the pump  400  is configured for direct line connection similar to the pump  300 . Preferably, the impeller  10  is inverted such that the snout  20  faces the drive shaft rather than facing away from the drive shaft as depicted in  FIGS. 4-7 . To accommodate the impeller  10  being inverted, a tube extension  410  and a drive shaft extension  412  are provided. Preferably, the impeller  10  comprises a central aperture extending from the snout  20 , through the base  14 , and to the hub  30  (comprising the threaded aperture  32 ) such that the drive shaft extension can be mounted thereto. In one example form, the tube extension  410  comprises a 2″ inch inlet where the inlet hose  140  mounts. Generally, the tube extension  410  is fixedly mounted between the pump housing  116  and a U-shaped ring  411  (mounted to the transverse flange  114  of the extension tube  112 ). Preferably, a direct line sealing hose  414  is provided between the outlet hose  142  and the extension tube  112  for supplying fluid within the extension tube  112  to maintain a seal. In one form, a control orifice or valve  420  is connected to the direct line sealing hose  414  to control the flow of the fluid flowing therein. Preferably, the control valve  420  is used to keep fluid or oil level at the proper height in extension tube, thus creating the liquid seal without the use of a tank. Optionally, other means may be used for controlling the flow within the direct line sealing hose  414  to maintain a constant fluid level in the extension tube  112 . Additionally, a bearing fluid return hose  416  is provided at the bottom of the pump housing  116  (proximal the hub  30  and bearing surface  34 ) to capture any fluid flowing past the bearing surface  34 . Preferably, the bearing fluid return hose extends from the bottom of the pump housing  116  to the inlet hose  140 . 
       FIG. 9  shows a pump  500  according to another example embodiment of the present invention. Generally, the pump is configured for connecting to an oil tank OT similar to pump  200 , and the impeller  10  is inverted similar to pump  400 . As depicted, the oil tank OT comprises an inlet hose  140  extending to the inlet portion of a tube extension  510  (which is connected to the inlet portion  120  of the pump housing  116 ), an outlet hose  142  extending to the outlet portion  122  of the pump housing  116 , a sealing hose  514  extending to a lower portion of the extension tube  112 , an excess sealing return hose  516  extending to an upper portion of the extension tube  112 , and an air vent tube  520  positioned and communicatively engaged proximal the uppermost portion of the extension tube  112 . A bolt  522  is mounted to a portion of the extension tube  112  (adjacent the ring  132 ) to hold the sleeve  130  down relative to the runner to ensure steam and vapor pressure do not push the sleeve  120  out of position, which could cause losing the liquid seal. Similarly to pump  400 , a bearing fluid return hose  530  is provided at the bottom of the pump housing  116  (proximal the hub  30  and bearing surface  34 ) to capture any fluid flowing past the bearing surface. Preferably, the bearing fluid return hose extends from the bottom of the pump housing  116  to the inlet hose  140 . Optionally, a filter and/or heat exchanger  524  can be connected to the outlet hose  142  to transfer heat and/or filter particles from the fluid before returning to the oil tank OT. Optionally, if the pump  500  is not connected to an oil tank OT, a direct line sealing hose  532  is provided between the outlet hose  142  and the extension tube  112  for supplying fluid within the extension tube  112  to maintain a seal. Similarly, a control orifice or valve  534  is connected to the direct line sealing hose  532  to control the flow of the fluid flowing therein. 
       FIGS. 10 and 11  show a pump  600  according to another example embodiment of the present invention. In many aspects, the pump  600  is generally similar to the embodiments described above, and can be configured with one or more similar components (e.g., a sealing hose  620 , etc.). Pump  600  preferably comprises a dual inlet impeller assembly  610 , which provides for maintaining a relatively constant level of liquid within the extension tube  112 . The dual impeller  610  preferably comprises first and second impellers  612 ,  614 , which are oriented such that the snouts  20  generally extend in opposite directions from each other. Thus, the bases  14  of each impeller  612 ,  614  are generally adjacent to one another. In one form, the dual impeller  610  is constructed by a casting process that forms the entire dual impeller  610  as an integral unitary component. Alternatively, one or more fasteners or other connection means can be used as desired to connect two impellers together to form the dual impeller  610 . Preferably, the vanes  12  of each impeller are oriented opposite of one another. For example, if the vanes  12  of the first impeller  612  are configured in a clockwise direction, then the vanes  12  of the second impeller  614  are configured in the counter-clockwise direction. This ensures that one impeller is not working against another impeller. Preferably, the dual impeller  610  is designed to pull liquid from the inlet portion  120  of the pump housing  116  as well as the extension tube  112  that is supporting the motor M. And, the purpose for the impeller  610  to pull fluid from the extension tube  112  is to ensure that a portion of the fluid leaving the labyrinth seal is returned back to the pump housing  116  and pumped through the outlet hose  142 . Thus, the dual impeller  610 , in addition to the sealing hose (and/or other hoses described above), provide a way to maintain the level of fluid within the extension tube  112 . 
     The improvements provided by the pump system of the present invention, including for example one or more of the structural design of the impeller, the drive shaft assembly sleeve, the piping arrangement from oil (or other fluid) source to the extension tube and from the pump inlet and outlet, advantageously produce a liquid sealed vertical pump that requires no shaft packing or mechanical seal for operation, and the pump can be run dry. The liquid or oil being pumped is the seal. The high temperature oil circulating pump U.S. Pat. No. 4,772,183, relied on a vacuum in the extension or support tube to keep tube clear of oil or fluid and prevent flooding of motor or motor bearings. This was not functional after the vacuum was lost due to vapor from the liquids forming in the extension tube. Vapor opened the relief valve at the top of the extension tube allowing flooding of the tube and motor bearings. Holes in the sleeve around the motor shaft let seal fluid weep out of the stationary shaft sleeve to help prevent oil or liquid entering the motor bearings. 
     The present invention further comprises the following component parts of example embodiments of a pump system: 
     Item No. 1: Highnote&#39;s Dynamic Turbo Tech Impeller produces a highly efficient flow of fluid or oil compared to standard enclosed or open face impellers. See  FIGS. 1-3 . The close tolerances of the bearing surfaces, and impeller vanes to the pump housing make the pump highly efficient. The first ever Semi open Face Impeller with extended snout working as a bearing service, and a vortex suction generator for pump inlet. The pump is very efficient with, for example, ninety percent of impeller vanes being open face and 0.005″ clearance between vanes and pump housing. See  FIG. 4 . The curvature of the vanes and diameter of the impeller determine the gallons per minute that can be pumped. The wiper vanes, pictured in example form in  FIG. 5 , provide improved overall performance of the pump through their ability to assist in keeping contaminants from entering the aft bearing of the impeller. The inlet snout is mounted on the open face vanes, for example by a casting process in producing the impeller, or the snout and base can be welded to the impeller vanes. This snout design with the open face impeller vanes will enhance the pump&#39;s ability to minimize leakage from pump housing, and therefore the impeller is more efficient. The semi open face vanes allow particles up to ¼″, in small quantities, to pass through the impeller. Particle pass-through is important when pumping cooking oil or other fluids contaminated with sediments and particles. Many different bearing materials can be used on the impeller and pump housing to enhance life of the pump. Fluid mediums determine the type bearing materials to be installed on impeller and pump housing. 
     Item No. 2: The impeller bearing surfaces, and their mounting position in pump housing. Figure shows standard pump head configuration. The second drawing shows a pump head with impeller inverted in relation to the pump flange and extension tube. Snout and Aft bearing surfaces in example forms of both pump designs have 0.002 clearance on each side of pump flange bearing surface. See  FIG. 8 . 
     Item No. 3: Hose and piping connection of standard pump configuration, and hose and piping connections for inverted impeller pump to a, fry tank configuration, and direct piping connection to pump inlets. These three drawings demonstrate the operation of the pumps:  FIG. 6 ,  FIG. 9 , and  FIG. 8 . 
     Item No. 4: The labyrinth runner, and drive shaft sleeve. The purpose of these two parts is to minimize the leakage from the pump head, and aeration from drive shaft spinning. Six ¼″ relief holes are drilled in shaft sleeve to keep shaft sleeve flooded with oil and to relieve excess oil from labyrinth runner. A bolt is placed in the support tube just above the top of the drive shaft sleeve to hold the sleeve in position from steam and vapor pressure pushing the sleeve out of position causing a loss of the liquid seal.  FIG. 5 ,  FIG. 7 . 
     Item No. 5: Suction return hose inlet side of pump allows return of oil or fluid from extension tube to inlet of pump impeller. Drawing No.  FIG. 7 , and  FIG. 6 . 
     Item No. 6: Balancing fluid in extension or support tube, through the return hose, and supply hose from the tank or outlet of pump head.  FIG. 9 , and  FIG. 7 . 
     Item No. 7: The vertical pump can be directly connected to an incoming liquid supply line instead of a tank connection. Tank connections are used for recirculation in most situations, similar to hot oil frying tanks. A direct liquid line connection to inlet of pump, utilizes a hose to be connected from the outlet side of pump head to the extension tube. This type of connection can be used for irrigation, boost, or sump pumps. This piping arrangement allows oil or fluid to flow into the extension tube. An orifice or control valve is used in outlet hose to keep fluid or oil level proper height in extension tube creating the liquid seal without the use of a tank.  FIG. 9 ,  FIG. 8  and  FIG. 7 . 
     Item No. 8: The liquid sealed components advantageously provide the ability to invert the impeller.  FIG. 8  and  FIG. 9 . The ability to do this allows easy return of liquid or oil from the extension tube directly to the impeller intake. The new oil supply inlet for the pump is on the side of the pump head at the inlet of the impeller. This configuration allows low head operation, along with ease of connection to tank applications. This is a significant improvement over horizontal pumps as far as the ability to adapt to many new pumping situations. Horizontal pumps are known for piping restrictions because of the inlet being horizontal with the pump motor. 
     The basic operation of the liquid sealed pump is as follows. This pump is vertically designed to take advantage of gravity, and provide a vessel to hold oil or fluid. The extension or motor support tube serves as this vessel. Advantageously, the pump can maintain a constant level of oil or fluid midway in the extension tube, producing a liquid seal. Maintaining oil or fluid in the midway point of the extension tube advantageously keeps the fluid away from the pump motor and the motor bearings. Highnote&#39;s Dynamic Turbo Tech Impeller keeps leakage to a minimum from pump head into extension tube. The extended snout and bearing surface create a vortex generator for the pump vanes, improving pumping qualities of the impeller. Another advantage of this impeller is the ability to pass particles through the unit and not clog the vanes. 
     The dual inlet impeller as shown on the two drawings is designed to pull liquid from the inlet side of the pump as well as the pump column tube supporting the motor. The purpose of the impeller pulling liquid from the pump column is to insure that a portion of the liquid leaving the labyrinth is returned back to the pump head and pumped through the outlet pipe. This provides a means by which a specific level of liquid can be maintained in the pump column providing a liquid seal. 
     The impeller is preferably cast in one unit. The inlet of the impeller on one side would have left hand rotating vanes while the other would have right hand rotating vanes producing liquid return from the pump inlet and labyrinth pump column. The dual inlet vanes and inlet snout would be the same as the impeller shown in  FIGS. 1-3 . The purpose again of the dual inlet impeller is to help maintain the liquid level in the pump column or pump support tube shown in  FIG. 7 . 
     The pump support tube is a vessel in which a liquid level is maintained by adding or taking liquid away from, by means of the pump impeller and the tank, or external hoses from the pump head. See  FIGS. 6 &amp; 9 . 
     While the invention has been described with reference to preferred and example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.