Patents Assigned to Nash Engineering Company
  • Patent number: 6394777
    Abstract: A rotary screw type pump is provided with internal cavities within the rotors. The rotors include shaft portions that extend out from the casing that contains the screw portion of the rotors. The cavities extend from the screw portion of the rotors at the compression side of the casing to the shaft portion of the rotors. The cavities are charged with a fluid and may include a porous wick in order to act similar to a heat pipe for removing the heat generated during pump compression. The heat is transferred to the shaft portion of the rotors. The shaft portion of the rotors extend into a cavity that contains a coolant. A water jacket surrounds the cavity. The heat is transferred from the shaft portion of the rotors to the coolant and then the water jacket for removal. The heat transfer from the shaft portions to the coolant may be facilitated with the use of fins.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: May 28, 2002
    Assignee: The Nash Engineering Company
    Inventor: Harold K. Haavik
  • Patent number: 6354808
    Abstract: Liquid ring pumps, of the type having a port structure that extends into an annular recess in an end of the rotor, have several parts that are designed so that they can be used to make pumps having either relatively demanding service requirements or substantially less demanding service requirements. Some of these parts can be substantially exactly the same in both final pump configurations. Others of these parts may be castings that differ substantially only in some subsequent machining in order to adapt them for each final pump configuration. Some of the final pump configurations have more compact mechanical seal structures and/or improved structures for supplying liquid to the seal structures.
    Type: Grant
    Filed: April 10, 2000
    Date of Patent: March 12, 2002
    Assignee: The Nash Engineering Company
    Inventors: Ramesh B. Shenoi, Carl G. Dudeck
  • Publication number: 20010031214
    Abstract: A rotary screw type pump is provided with internal cavities within the rotors. The rotors include shaft portions that extend out from the casing that contains the screw portion of the rotors. The cavities extend from the screw portion of the rotors at the compression side of the casing to the shaft portion of the rotors. The cavities are charged with a fluid and may include a porous wick in order to act similar to a heat pipe for removing the heat generated during pump compression. The heat is transferred to the shaft portion of the rotors. The shaft portion of the rotors extend into a cavity that contains a coolant. A water jacket surrounds the cavity. The heat is transferred from the shaft portion of the rotors to the coolant and then the water jacket for removal. The heat transfer from the shaft portions to the coolant may be facilitated with the use of fins.
    Type: Application
    Filed: December 29, 2000
    Publication date: October 18, 2001
    Applicant: The Nash Engineering Company
    Inventor: Harold K. Haavik
  • Patent number: 6104987
    Abstract: A system is provided for monitoring the temperature of dryer drums in papermaking or textile machinery. Wireless temperature sensors are mounted to each dryer drum. Sensor pickup devices receive temperature signals from the temperature sensors that are processed by a computer. Multiplexers may be used to provide the signals from multiple sensor pickup devices to a radio-frequency transmitter. A radio-frequency receiver may be used to receive signals from the transmitter and provide these signals to a computer. The computer determines the temperature of the drums by processing the temperature signals. The computer may provide control signals to a distributed control system to control the temperature of the drums (e.g., by controlling the flow of steam into the dryer section).
    Type: Grant
    Filed: October 3, 1997
    Date of Patent: August 15, 2000
    Assignee: The Nash Engineering Company
    Inventor: David C. Farnsworth
  • Patent number: 5961295
    Abstract: A conically ported liquid ring pump has one or more port structures with cone angles in the range from 15 degrees to 75 degrees. These cone angles are substantially greater than previously used cone angles (most commonly about 8 degrees). The large cone angles of this invention give the fluid flowing between the cone and the rotor significant components of both radial and axial velocity. Large cone angles also allow the port structure(s) to be made axially shorter, which has a number of important advantages such as shortening the unsupported length of the rotor shaft. These attributes of the present pumps are helpful for such purposes as allowing the length-to-diameter ratios of the pumps to be economically increased. In addition, the pumps of this invention retain many of the desirable attributes of conically ported pumps.
    Type: Grant
    Filed: July 3, 1997
    Date of Patent: October 5, 1999
    Assignee: The Nash Engineering Company
    Inventors: Harold K. Haavik, Douglas Frederick Sweet
  • Patent number: 5899668
    Abstract: A two-stage liquid ring pump has an interstage structure which promotes separation of the gas and liquid discharged from the first stage. The second stage has separate gas and liquid inlets for respectively admitting the separated gas and liquid to the second stage. This avoids any possible choking of the second stage gas inlet by liquid, thereby improving the performance of the pump.
    Type: Grant
    Filed: January 30, 1997
    Date of Patent: May 4, 1999
    Assignee: The Nash Engineering Company
    Inventors: Ramesh B. Shenoi, Carl G. Dudeck
  • Patent number: 5653582
    Abstract: Liquid ring pumps with rotating canisters are supported by at least one radial fluid bearing pad. The bearing fluid is either a gas or a liquid. The radial fluid bearing pads can be of either the hydrodynamic or hydrostatic type. Holes in each bearing pad are used to introduce bearing fluid to the clearance between the rotating canister and the housing of the pump. Each radial bearing pad can be mounted to the housing using a ball joint or a bladder. Access ports formed in the housing provide access to the radial bearing pads. Axial fluid bearings are mounted to the housing using shims or threaded bolts so that the axial position of the axial bearings can be adjusted.
    Type: Grant
    Filed: September 26, 1995
    Date of Patent: August 5, 1997
    Assignee: The Nash Engineering Company
    Inventors: Andrew C. Harvey, Richard G. Cadotte, Thomas R. Dardis, Harold K. Haavik, Ellis J. Cooper
  • Patent number: 5507625
    Abstract: To decrease gas leakage across the cantilevered axial end of the hub of a liquid ring pump rotor which has a central recess in that end of the hub, the adjacent port structure is provided with a protrusion which extends axially part way into the recess in the rotor hub. A relatively small clearance is provided between the radially outer surface of the protrusion and the radially adjacent inner surface of the recess. This clearance is filled with liquid and thereby increases the area of the seal at the adjacent axial end of the rotor hub.
    Type: Grant
    Filed: April 14, 1995
    Date of Patent: April 16, 1996
    Assignee: The Nash Engineering Company
    Inventor: Carl G. Dudeck
  • Patent number: 5469705
    Abstract: In a power plant having a boiler for heating a fluid to form a gaseous phase, a power generator for generating electrical power from the gaseous phase, a condenser for condensing the gaseous phase after the gaseous phase has passed through the power generator, a liquid ring pump for evacuating uncondensed gaseous phase from the condenser, and a chiller for cooling seal liquid discharged from the liquid ring pump for re-use in the liquid ring pump, apparatus is provided for utilizing the heat generated during the operation of the chiller to heat a predetermined portion of the fluid supplied to the boiler, thereby reducing the amount of heat which must be provided by the boiler to form a gaseous phase of the fluid so that electricity can be generated. The efficiency of the power plant is thereby increased.
    Type: Grant
    Filed: August 22, 1994
    Date of Patent: November 28, 1995
    Assignee: The Nash Engineering Company
    Inventor: John K. Glenn, Jr.
  • Patent number: 5427685
    Abstract: A separator body 23 has a cylindrical internal surface 24 having an axis A arranged in use substantially horizontally. An inlet 19, 20 for a gas and liquid mixture, and respective outlets 53, 30 are provided in the body 23 for the liquid L and gas. The inlet 19, 20 is arranged such that the mixture leaving the inlet is directed substantially tangentially to the internal surface 24, whereby incoming mixture will travel circumferentially around the surface 24 to cause the liquid and gas to separate by centrifugal action. Catchment means 47 is provided which catches the liquid L travelling around the cylindrical internal surface 24 after separation of gas therefrom so as to direct the liquid toward its outlet 53.
    Type: Grant
    Filed: June 14, 1993
    Date of Patent: June 27, 1995
    Assignee: The Nash Engineering Company
    Inventor: Robert J. Thorley
  • Patent number: 5395215
    Abstract: A support structure for the rotatable housing of a liquid ring pump includes a stationary structure disposed circumferentially around the housing, and a plurality of rollers rotatably and removably mounted on the stationary structure. The rollers support the housing for rotation, and they are distributed axially along and circumferentially about the housing so that any one roller can be removed (e.g., for repair or replacement) without disturbing operation of the pump.
    Type: Grant
    Filed: July 26, 1994
    Date of Patent: March 7, 1995
    Assignee: The Nash Engineering Company
    Inventors: Thomas R. Dardis, Christopher D. Boczer
  • Patent number: 5370502
    Abstract: Liquid ring pumps with rotating liners supported by a bearing fluid (pressurized liquid or compressed gas) have a bearing fluid distribution system that compensates for the radially unsymmetric load on the rotating liner. If the liner bearing fluid is compressed gas, the axial ends of the liner may be either open and unsealed so that expended bearing gas escapes into the liquid ring in the pump, or the axial ends of the Liner may be partly closed by radially inwardly extending end plates. Various mechanical and/or liquid seal structures may be used in conjunction with the end plates to seal the axial ends of the liner and/or to flush the clearances adjacent the axial ends of the liner.
    Type: Grant
    Filed: December 17, 1993
    Date of Patent: December 6, 1994
    Assignee: The Nash Engineering Company
    Inventors: Harold K. Haavik, Kaj Holm
  • Patent number: 5356268
    Abstract: In a liquid ring pump having a port member with at least one auxiliary gas discharge port in addition to the main gas discharge port, an auxiliary gas discharge conduit is provided to extend the auxiliary gas discharge port so that a relatively large check valve can be more easily provided for the auxiliary port. The auxiliary discharge conduit is preferably provided in the head member of the pump, and it preferably extends away from the auxiliary port in a generally radial direction. This allows the check valve to be placed at a less congested location in the pump, which facilitates provision of a larger check valve and also access to the check valve for such purposes as maintenance of the check valve.
    Type: Grant
    Filed: September 29, 1993
    Date of Patent: October 18, 1994
    Assignee: The Nash Engineering Company
    Inventors: Louis J. Lengyel, Ramesh B. Shenoi
  • Patent number: 5295794
    Abstract: Liquid ring pumps with rotating liners supported by a bearing fluid (pressurized liquid or compressed gas) have a bearing fluid distribution system that compensates for the radially unsymmetric load on the rotating liner. If the liner bearing fluid is compressed gas, the axial ends of the liner may be either open and unsealed so that expended bearing gas escapes into the liquid ring in the pump, or the axial ends of the liner may be partly closed by radially inwardly extending end plates. Various mechanical and/or liquid seal structures may be used in conjunction with the end plates to seal the axial ends of the liner and/or to flush the clearances adjacent the axial ends of the liner.
    Type: Grant
    Filed: January 14, 1993
    Date of Patent: March 22, 1994
    Assignee: The Nash Engineering Company
    Inventor: Harold K. Haavik
  • Patent number: 5217352
    Abstract: A two-stage liquid ring gas pump has a rotatable liner supported on a liquid bearing in the first stage housing. The liquid for the liner bearing is withdrawn from the second stage liquid ring and is therefore at a pressure which is high enough to support the liner for rotation without the need for any other component such as a liquid pump to pressurize it for that purpose.
    Type: Grant
    Filed: April 29, 1992
    Date of Patent: June 8, 1993
    Assignee: The Nash Engineering Company
    Inventor: Harold K. Haavik
  • Patent number: 5213479
    Abstract: In liquid ring gas pumps of the type having a rotor rotatably mounted in a stationary housing for forming a quantity of pumping liquid into a recirculating ring inside the housing, fluid friction loss between the liquid and the housing is reduced by shaping the surface of the housing which is in contact with the liquid ring radially outside the rotor so as to minimize or at least substantially reduce the area of that surface.
    Type: Grant
    Filed: April 9, 1992
    Date of Patent: May 25, 1993
    Assignee: The Nash Engineering Company
    Inventors: Thomas R. Dardis, Douglas E. Bissell, Richard F. Gordon
  • Patent number: 5197863
    Abstract: In liquid ring pumps having rotating lobe liners supported by a bearing fluid in an annular clearance between the liner and the surrounding housing, the housing has at least one substantially annular channel formed in the housing for distributing the bearing fluid to a plurality of circumferentially spaced apertures extending through the housing from the channel to the clearance.
    Type: Grant
    Filed: January 22, 1992
    Date of Patent: March 30, 1993
    Assignee: The Nash Engineering Company
    Inventors: Thomas R. Dardis, Douglas E. Bissell, Harold K. Haavik
  • Patent number: 5147508
    Abstract: A suction box for use in drying a felt web in a papermaking machine has one or more cover members in contact with a surface of the felt web. The surface of at least one of these cover elements which normally contacts the felt web has a leading portion which is feathered or inclined away from the surface of the felt web in the direction opposite the direction of motion of the felt web. This allows the felt web to come into contact with the cover member surface more gradually, which reduces wear on the felt.
    Type: Grant
    Filed: October 11, 1991
    Date of Patent: September 15, 1992
    Assignee: The Nash Engineering Company
    Inventor: Douglas F. Sweet
  • Patent number: 5131817
    Abstract: In a gas pumping system including a first stage rotary lobe pump for pumping gas to a second stage liquid ring pump, cooling liquid is injected into the compression zone of the rotary lobe pump so that the liquid mixes intimately with the gas being compressed in that zone and reduces the temperature rise of the gas in that zone in order to reduce heat transfer from that gas to the lobes of the rotary lobe pump.
    Type: Grant
    Filed: March 22, 1990
    Date of Patent: July 21, 1992
    Assignee: The Nash Engineering Company
    Inventor: Michael J. Pastore, Jr.
  • Patent number: D405096
    Type: Grant
    Filed: January 5, 1998
    Date of Patent: February 2, 1999
    Assignee: The Nash Engineering Company
    Inventor: Carl G. Dudeck