Patents Assigned to Rotoflow Corporation
  • Patent number: 6310414
    Abstract: A turboexpander associated with a rotary compressor by means of a rotor shaft connecting the two. A bearing housing includes magnetic radial and thrust bearings which control the placement and dynamics of the shaft within the housing. A control passageway extends from the inlet of the compressor to the gas cavity behind the compressor rotor. This passage is controlled by a valve and in turn by the magnetic bearing controller to augment the operation of the active magnetic thrust bearings.
    Type: Grant
    Filed: June 21, 1994
    Date of Patent: October 30, 2001
    Assignee: Rotoflow Corporation
    Inventors: Reza R. Agahi, Behrooz Ershaghi
  • Patent number: 5769602
    Abstract: An automatic control of clamping forces in primary nozzle systems of radial turbines. Pressure to an closed annular volume positioned between a turbine housing and an axially adjustable mounting ring is varied to regulate the clamping forces against inlet vanes which form primary nozzles. A controller compares process control data with a signal indicative of operational deviation from nominal operation as indicated by the process control signal to detect onset of excessive blow-by, in which case pressure is increased in the closed annular volume to move the mounting rings closer together. The controller also compares expected and actual system data to detect onset of excessive clamping, in which case pressure is increased in the closed annular volume to increase clamping forces.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: June 23, 1998
    Assignee: Rotoflow Corporation
    Inventors: Reza R. Agahi, Behrooz Ershagi
  • Patent number: 5651661
    Abstract: Rotary fluid handling apparatus employing a wheel to provide multi-stage compression or expansion. A wheel having a first set of vanes includes a shroud about those vanes with a second set of vanes outwardly of the shroud. One set of vanes provides for low specific speed flow while the other set of vanes provides for high specific speed flow. A transfer passage interconnects the outlet of the first stage with the inlet of the second stage. The difference in temperature between the inlet flow to the system and the outlet flow from the system may be exchanged to increase efficiency. The multi-stage wheel and associated passages may be configured for either compression or turboexpansion.
    Type: Grant
    Filed: August 5, 1996
    Date of Patent: July 29, 1997
    Assignee: Rotoflow Corporation
    Inventors: Reza R. Agahi, Behrooz Ershagi
  • Patent number: 5564895
    Abstract: An automatic control of clamping forces in primary nozzle systems of radial turbines. Pressure to an closed annular volume positioned between a turbine housing and an axially adjustable mounting ring is varied to regulate the clamping forces against inlet vanes which form primary nozzles. A controller compares process control data with nozzle position data to detect onset of excessive blow-by, in which case pressure is increased in the closed annular volume to move the mounting rings closer together. The controller also compares expected and actual system data to detect onset of excessive clamping, in which case pressure is increased in the closed annular volume to increase clamping forces.
    Type: Grant
    Filed: April 26, 1995
    Date of Patent: October 15, 1996
    Assignee: Rotoflow Corporation
    Inventors: Reza R. Agahi, Behrooz Ershagi
  • Patent number: 5555745
    Abstract: A refrigeration system employing a motor driven compressor with an associated turboexpander coupled to the motor of the compressor. The compressor draws incoming air through a heat exchanger and a dehydrator. The compressor discharges compressed air through a high temperature heat exchanger and the other side of the heat exchanger on the inlet side of the compressor. The compressed air is then expanded through the turboexpander and used for cooling. The high temperature heat exchanger is employed for hot water generation.
    Type: Grant
    Filed: April 5, 1995
    Date of Patent: September 17, 1996
    Assignee: Rotoflow Corporation
    Inventors: Reza R. Agahi, Behrooz Ershagi
  • Patent number: 5553458
    Abstract: A closed-loop system that dissipates energy from an expander and does not contaminate the expander. The noncontaminating energy dissipator has a closed-loop conduit that is connected to a compressor, a pressure reduction valve and a heat exchanger. A brake gas circulates in the closed-loop conduit from the compressor to the pressure reduction device, then to the heat exchanger and finally back to the compressor, where the process repeats. The use of an inert brake gas prevents interactions between the brake gas and a hazardous process fluid from forming an explosive mixture. The closed-loop conduit has an outlet so that the brake gas can be used for purposes other than circulating through the closed-loop. A make-up conduit and another control valve can be added to the noncontaminating energy dissipator so that brake gas that is lost through seals or other parts of the system can be readily replaced.
    Type: Grant
    Filed: September 27, 1995
    Date of Patent: September 10, 1996
    Assignee: Rotoflow Corporation
    Inventors: Reza R. Agahi, Behrooz Ershaghi
  • Patent number: 5545006
    Abstract: Rotary fluid handling apparatus employing a wheel to provide multi-stage compression or expansion. A wheel having a first set of vanes includes a shroud about those vanes with a second set of vanes outwardly of the shroud. One set of vanes provides for low specific speed flow while the other set of vanes provides for high specific speed flow. A transfer passage interconnects the outlet of the first stage with the inlet of the second stage. The difference in temperature between the inlet flow to the system and the outlet flow from the system may be exchanged to increase efficiency. The multistage wheel and associated passages may be configured for either compression or turboexpansion.
    Type: Grant
    Filed: May 12, 1995
    Date of Patent: August 13, 1996
    Assignee: Rotoflow Corporation
    Inventors: Reza R. Agahi, Behrooz Ershagi
  • Patent number: 5045711
    Abstract: A turboexpander-generator system employing a housing with a rotatably mounted shaft oriented vertically with a turboexpander associated with the upper end of the housing and shaft, a generator associated with the housing and shaft below the turboexpander and a lubricant pump located at the lower end of the housing and shaft. The lubricant pump controls an actuator valve which controls the variable inlet nozzles to the turboexpander. Thus, a speed control system is achieved through use of the lubricant pump pressure. A seal gas separator is provided with two ports located in the turboexpander exducer at positions of different pressure. High pressure is used to provide a seal between the bearings and the turboexpander. Low pressure is directed to the area of the sump of the pump to enhance continuous lubricant return. A self-priming mechanism causes a reservoir to be charged during pump operation with return of the lubricant to the sump when the pump is off.
    Type: Grant
    Filed: August 21, 1989
    Date of Patent: September 3, 1991
    Assignee: Rotoflow Corporation
    Inventor: Judson S. Swearingen
  • Patent number: 5002459
    Abstract: A surge control system for a compressor comprising a bypass passage controlled by a bypass valve to return flow to the compressor inlet for avoiding surge in the compressor. The bypass valve is controlled through a sensing of a compressor speed and flow. The compressor speed and the square root of the flow signal, which is proportional to the actual flow, are presented as a ratio for comparison with an empirically established constant. When the conditions of the compressor system are such that the ratio approaches the constant, the bypass valve is opened and the compressor experiences increased flow therethrough.
    Type: Grant
    Filed: July 28, 1988
    Date of Patent: March 26, 1991
    Assignee: Rotoflow Corporation
    Inventors: Judson S. Swearingen, Reza Agahi
  • Patent number: 4789300
    Abstract: A radial inflow turbine having an axial discharge divided into concentric passages. The inner concentric passage or passages may be selectively blocked by means of a valve to accommodate a first range of flow rate. At higher flow rates, the valve is open to increase the effective nozzle area of the secondary nozzles at the discharge of the turbine wheel.
    Type: Grant
    Filed: June 16, 1983
    Date of Patent: December 6, 1988
    Assignee: Rotoflow Corporation
    Inventor: Judson S. Swearingen
  • Patent number: 4722663
    Abstract: A seal-off mechanism for preventing migration of working fluid along a turbine shaft which includes a floating seal ring and a shaft shoulder. The seal ring is spring biased against the shaft shoulder. During turbine operation, a pressurized fluid moves the ring away from the shoulder. The pressurized fluid then flows toward the turbine to contain the working fluid. A chamber collects the pressurized fluid and the working fluid for subsequent separation and reuse.
    Type: Grant
    Filed: February 4, 1986
    Date of Patent: February 2, 1988
    Assignee: Rotoflow Corporation
    Inventor: Judson S. Swearingen
  • Patent number: 4695221
    Abstract: A turbine shutdown control system for controlling a turbine powering two load groups. Upon loss of one load group, a first control valve will close to interrupt the fluid flow to the turbine. A second modulating valve in parallel with the first valve remains open to provide sufficient fluid flow to the turbine to power the second load group.
    Type: Grant
    Filed: December 4, 1985
    Date of Patent: September 22, 1987
    Assignee: Rotoflow Corporation
    Inventor: Judson S. Swearingen
  • Patent number: 4606652
    Abstract: A cryogenic turboexpander employing a rotor and a shaft fixed thereto including bearings rotatably supporting the shaft having a pressurized lubricating system. A labyrinth seal is positioned between the bearings and the rotor. A control valve is employed to sense differential pressure across a portion of the seal and regulate the pressure within a cavity between the seal and a near bearing.
    Type: Grant
    Filed: June 20, 1984
    Date of Patent: August 19, 1986
    Assignee: Rotoflow, Corporation
    Inventor: Judson S. Swearingen
  • Patent number: 4390082
    Abstract: A system for supplying lubricant under pressure to a rotary mounting system having bearings when the main pressurized lubricant supply system fails. The system includes a bladder or other expansible chamber in association with a lubricant reservoir. The bladder has a source of pressurized gas which is either inherently or through regulation maintained at a pressure below that of the main system and above that of the lubricant discharge from the bearings. The source of pressure for the reserve system may be pressure from a gas seal or from the rotor chamber of a pump or turbine. If regulated, the regulation may be by the main lubricant pressure or the pressure of the lubricant discharge. The system also contemplates accommodation for leaks and over pressures.
    Type: Grant
    Filed: December 18, 1980
    Date of Patent: June 28, 1983
    Assignee: Rotoflow Corporation
    Inventor: Judson S. Swearingen
  • Patent number: 4385768
    Abstract: A device for accommodating and measuring thrust loads on a rotatably mounted shaft wherein the thrust loading is in either axial direction. The rotatably mounted shaft has two shoulders facing in opposite axial directions which cooperate with a pair of thrust bearings to constrain the shaft to a limited range of axial movement. Thrust rings associated with the shoulders are positioned between the shoulders and the bearings and are biased toward the bearings by resilient members to resist the axial movement of the shaft between the bearings. Sensing systems are arranged to measure the axial displacement of the shaft and provide input to thrust monitoring and control systems. A method for preventing damage to labyrinth seals on the shaft during start up of the equipment is also provided.
    Type: Grant
    Filed: April 17, 1981
    Date of Patent: May 31, 1983
    Assignee: Rotoflow Corporation, Inc.
    Inventor: Judson S. Swearingen
  • Patent number: 4311004
    Abstract: A system and method are disclosed for processing an oxygen-containing gas for use in a chemical process producing a generally inert gas. A fluid handling rotor is carried by a rotary shaft for effecting a pressure change in the oxygen-containing gas. A housing surrounds the rotor and the adjacent portion of the shaft. A bearing, axially spaced from the rotor, supports the shaft in the housing for rotation. Lubricant is injected into the bearing and is caused to flow through the bearing and axially toward the rotor. A seal surrounds the shaft intermediate the rotor and the bearing and seals between the shaft and housing. A generally inert seal gas is extracted from the products of the chemical process and injected into the seal under a pressure greater than the pressures within the housing on either side of and immediately adjacent the seal.
    Type: Grant
    Filed: October 26, 1979
    Date of Patent: January 19, 1982
    Assignee: Rotoflow Corporation
    Inventor: Anthony A. du Pont
  • Patent number: 4287758
    Abstract: A device for accommodating and measuring thrust loads on a rotatably mounted shaft wherein the thrust loading is in either axial direction. The rotatably mounted shaft has two shoulders facing in opposite axial directions which cooperate with a pair of thrust bearings to constrain the shaft to a limited range of axial movement. Thrust rings associated with the shoulders are positioned between the shoulders and the bearings and are biased toward the bearings by resilient members to resist the axial movement of the shaft between the bearings. Sensing systems are arranged to measure the axial displacement of the shaft and provide input to thrust monitoring and control systems. A method for preventing damage to labyrinth seals on the shaft during start up of the equipment is also provided.
    Type: Grant
    Filed: July 19, 1979
    Date of Patent: September 8, 1981
    Assignee: Rotoflow Corporation, Inc.
    Inventor: Judson S. Swearingen
  • Patent number: 4273390
    Abstract: The present invention pertains to a thrust bearing system including a thrust bearing structure having at least one pair of opposed bearing faces defining a bearing space therebetween, and a sub-system for delivering lubricant to the bearing space. A load sensor is provided in association with the bearing structure for determining the loads on the bearing faces. A thrust compensation sub-system is operably associated with the load sensor. This thrust compensation sub-system is operative, upon sensing by the load sensor of a thrust load on the bearing faces in excess of a predetermined limit, to increase the pressure of lubricant being delivered to the bearing space.
    Type: Grant
    Filed: May 15, 1978
    Date of Patent: June 16, 1981
    Assignee: Rotoflow Corporation
    Inventors: Judson S. Swearingen, Michael D. Irvine
  • Patent number: 4242040
    Abstract: The invention comprises a rotary fluid handling apparatus having first and second coaxial bodies mounted for relative axial movement therebetween and having respective opposed radially facing annular surfaces. The bodies may be, for example, the stator of a turboexpander or compressor and a relatively rotatable clamping ring for a plurality of adjustable blades. A first seal including a sealing ring is disposed between and seals between the annular surfaces, and the apparatus defines a first pressure zone which communicates with one axial side of the seal. The first body has a first stop engageable with the sealing ring to permit the force exerted on the sealing ring by the pressure of the first zone to be transmitted to the first body.
    Type: Grant
    Filed: March 21, 1979
    Date of Patent: December 30, 1980
    Assignee: Rotoflow Corporation
    Inventor: Judson S. Swearingen