Patents by Inventor Chidambaram Raghavan
Chidambaram Raghavan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 6736407Abstract: High-pressure static seals and pressure vessels with static seals for containing fluid at high pressures are shown and described. Embodiments of the invention allow a plug to be easily, manually inserted into and removed from the pressure vessel. A metallic ring in the seal is configured to expand under pressure to prevent an O-ring in the seal from being extruded into a gap between the plug and the vessel wall, but not to expand so much as to cause galling or similar damage when the seal moves with respect to the wall under elevated pressure.Type: GrantFiled: December 27, 2001Date of Patent: May 18, 2004Assignee: Flow International CorporationInventors: Olivier L. Tremoulet, Jr., Lennart Svensson, Chidambaram Raghavan, Mohamed Hashish
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Publication number: 20030122322Abstract: High-pressure static seals and pressure vessels with static seals for containing fluid at high pressures are shown and described. Embodiments of the invention allow a plug to be easily, manually inserted into and removed from the pressure vessel. A metallic ring in the seal is configured to expand under pressure to prevent an O-ring in the seal from being extruded into a gap between the plug and the vessel wall, but not to expand so much as to cause galling or similar damage when the seal moves with respect to the wall under elevated pressure.Type: ApplicationFiled: December 27, 2001Publication date: July 3, 2003Applicant: FLOW INTERNATIONAL CORPORATIONInventors: Olivier L. Tremoulet, Lennart Svensson, Chidambaram Raghavan, Mohamed Hashish
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Publication number: 20030037654Abstract: An improved apparatus for generating a high-pressure fluid jet includes an orifice mount having a frusto-conical surface that engages a frusto-conical wall in a cutting head, the geometry of the orifice mount and cutting head being selected to increase the stability of the mount and reduce deflection of the mount adjacent a jewel orifice, when subjected to pressure. Alignment of a nozzle body and the cutting head is improved by providing pilot diameters both upstream and downstream of threads on the nozzle body and bore of the cutting head, respectively. Accurate placement of a mixing tube in a cutting head is achieved by rigidly fixing a collar to an outer surface of the mixing tube, the collar engaging a shoulder and bore of the cutting head downstream of a mixing chamber, to precisely locate the mixing chamber axially and radially.Type: ApplicationFiled: April 1, 2002Publication date: February 27, 2003Inventors: Felix M. Sciulli, Mohamed A. Hashish, Steven J. Craigen, Bruce M. Schuman, Chidambaram Raghavan, Andreas Meyer, Wayne Johnson
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Publication number: 20020191970Abstract: An assembly for changing the temperature of ultrahigh-pressure fluid as it flows through ultrahigh-pressure tubing includes several thermally conductive blocks. Each block has a first bore through which the ultrahigh-pressure tubing passes, and a second bore containing a source of heating or cooling. Alternatively, resistance heating is used to increase the temperature of the ultrahigh-pressure fluid, by coupling electrodes to the outer surface of the tubing. The ultrahigh-pressure fluid is heated or cooled after it is pressurized, and is then discharged from the ultrahigh-pressure tubing at a selected temperature for use. For example, the ultrahigh-pressure fluid at a selected temperature may be discharged through a nozzle to form an ultrahigh-pressure fluid jet to cut or clean any desired surface or object, or it may be discharged to a pressure vessel to pressure treat a substance.Type: ApplicationFiled: June 15, 2001Publication date: December 19, 2002Applicant: Flow International CorporationInventors: Chidambaram Raghavan, Edmund Y. Ting, Bruce M. Schuman, Mohamed A. Hashish
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Publication number: 20020011579Abstract: An apparatus and method for pressure processing a pumpable substance, such as a pumpable food product or slurry. In one embodiment, the apparatus includes a pressure vessel having an inlet valve toward one end and outlet valve toward the other end. A flexible bladder is coupled between the inlet and outlet valves for receiving the pumpable substance. The pressure vessel can further include a high-pressure inlet port for receiving high-pressure fluid that biases the membrane inwardly to pressure process the pumpable substance. The pumpable substance is then removed from the vessel through the outlet valve.Type: ApplicationFiled: September 25, 2001Publication date: January 31, 2002Inventors: Mohamed A. Hashish, Chidambaram Raghavan, Olivier L. Tremoulet, Bruce M. Schuman
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Publication number: 20020009369Abstract: An apparatus and method for pressure processing a pumpable substance, such as a pumpable food product or slurry. In one embodiment, the apparatus includes a pressure vessel having an inlet valve toward one end and outlet valve toward the other end. A flexible bladder is coupled between the inlet and outlet valves for receiving the pumpable substance. The pressure vessel can further include a high-pressure inlet port for receiving high-pressure fluid that biases the membrane inwardly to pressure process the pumpable substance. The pumpable substance is then removed from the vessel through the outlet valve.Type: ApplicationFiled: September 25, 2001Publication date: January 24, 2002Inventors: Mohamed A. Hashish, Chidambaram Raghavan, Olivier L. Tremoulet, Bruce M. Schuman
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Publication number: 20010041206Abstract: An apparatus and method for pressure processing a pumpable substance, such as a pumpable food product. In one embodiment, the apparatus includes a plurality of coupled pressure vessels, each having an inlet port to receive the pumpable substance, an outlet port to remove the pumpable substance, an isolator to pressurize the pumpable substance and a high-pressure port for receiving pressurizing fluid to bias the isolator toward the pumpable substance. The apparatus can further include blocking valves to limit the travel of materials that may leak through the inlet and outlet valves, a heat exchanger to heat and/or cool the pumpable substance, and/or a gas controller to add gas to the pumpable substance or remove gas from the pumpable substance. Cleaning, rinsing, and/or sanitizing fluid can be pumped through the entire system, including through the isolator to cleanse and/or sanitize.Type: ApplicationFiled: July 17, 2001Publication date: November 15, 2001Inventors: Chidambaram Raghavan, Olivier L. Tremoulet, Mohamed A. Hashish, Edmund Ting
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Patent number: 6305913Abstract: An apparatus and method for pressure processing a pumpable substance, such as a pumpable food product or slurry. In one embodiment, the apparatus includes a pressure vessel having an inlet valve toward one end and outlet valve toward the other end. A flexible bladder is coupled between the inlet and outlet valves for receiving the pumpable substance. The pressure vessel can further include a high-pressure inlet port for receiving high-pressure fluid that biases the membrane inwardly to pressure process the pumpable substance. The pumpable substance is then removed from the vessel through the outlet valve.Type: GrantFiled: August 13, 1999Date of Patent: October 23, 2001Assignee: Flow International CorporationInventors: Mohamed A. Hashish, Chidambaram Raghavan, Olivier L. Tremoulet, Jr., Bruce M. Schuman
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Patent number: 6158981Abstract: Improved methods and apparatus for pressure processing of pumpable substances are shown and described. In one embodiment, the apparatus includes an inlet valve, an outlet valve, and a pressure vessel. The inlet valve has an inlet port, and is coupled to a source of a pumpable substance and to the pressure vessel. The outlet valve has an outlet port and is coupled to the pressure vessel. When the inlet valve is opened and the outlet valve is closed, a volume of pumpable substance may flow into the pressure vessel. The inlet valve is then closed and the outlet valve remains closed, and the pumpable substance within the pressure vessel may be pressurized to a selected pressure for a selected period of time. The outlet valve is then opened, allowing the pumpable substance to be discharged.Type: GrantFiled: June 18, 1998Date of Patent: December 12, 2000Assignee: Flow International CorporationInventors: Chidambaram Raghavan, Bruce Schuman, Curtis Anderson, Edmund Ting
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Patent number: 6145845Abstract: A method and apparatus for biasing a seal assembly in a high pressure fluid pump. In one embodiment, the fluid pump includes a reciprocating plunger, a seal carrier disposed about the plunger, and a seal supported by the seal carrier and sealably engaged with the plunger. The seal may be biased toward the seal carrier with a spring and may include a flange that engages the spring to restrict lateral motion of a spring relative to the reciprocating plunger. The flange may engage an inner and/or an outer surface of the spring. Where the spring is a coil spring, the flange may be continuous around the circumference of the spring or may include a plurality of spaced apart projections located around the circumference of the spring.Type: GrantFiled: May 1, 1998Date of Patent: November 14, 2000Assignee: Flow International CorporationInventors: Olivier L. Tremoulet, Jr., Chidambaram Raghavan, Katherine M. Madden
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Patent number: 6113304Abstract: A coupling for a high pressure fluid seal assembly is shown and described. The coupling includes a first member having first and second opposite ends and capable of motion along a first axis extending between the first and second ends. The first member has an engagement portion positioned toward the first end having a rounded convex engagement surface. The coupling further includes a second member also having first and second opposite ends and capable of motion along a second axis extending between the first and second ends of the second member. A second engagement portion toward the second end of the second member has a substantially flat second engagement surface engaging the first engagement surface of the first member. The interface between the first and second engagement surfaces aligns motion of the first member along the first axis with motion of the second member along the second axis. The coupling accordingly reduces the tendency for either the first or second member to bend.Type: GrantFiled: September 18, 1997Date of Patent: September 5, 2000Assignee: Flow International CorporationInventors: Olivier L. Tremoulet, Jr., Chidambaram Raghavan
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Patent number: 6092370Abstract: A method and apparatus for diagnosing components in high-pressure pumps to indicate when a component of the pump head is malfunctioning and to identify the malfunctioning component. In one embodiment, a high-pressure pump head incorporating a diagnostic system in accordance with the invention has a pressurization chamber and a pressurizing member at least partially received in the pressurization chamber. The pressurizing member moves within the pressurization chamber along an intake action to draw fluid into the pressurization chamber and along a pressurizing action to compress fluid in the pressurization chamber. An inlet fluid control assembly is coupled to the pressurization chamber to allow fluid to enter the pressurization chamber during the intake action, and a pressurized fluid control assembly is coupled between the pressurization chamber and an outlet chamber to selectively allow pressurized fluid into the outlet chamber during the pressurizing action.Type: GrantFiled: September 16, 1997Date of Patent: July 25, 2000Assignee: Flow International CorporationInventors: Olivier L. Tremoulet, Jr., Chidambaram Raghavan, Edmund Y. Ting
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Patent number: 6086070Abstract: A high pressure fluid seal assembly is shown and described. The seal assembly includes a seal carrier having a bore through which a reciprocating pump plunger may pass, the seal carrier having a first annular groove concentric with the bore, and carrying an annular seal. The seal carrier further includes an integral annular guidance bearing positioned in a second annular groove of the seal carrier, the second annular groove and guidance bearing contained therein being axially spaced from the first annular groove and seal contained therein. An inner diameter of the guidance bearing is smaller than an inner diameter of the seal carrier in a region between the seal and the guidance bearing. The seal is therefore supported directly by the seal carrier, although the seal carrier is spaced from the reciprocating plunger by the guidance bearing. Frictional heating in the region of the seal is therefore reduced, thereby increasing the life of the seal.Type: GrantFiled: September 18, 1997Date of Patent: July 11, 2000Assignee: Flow International CorporationInventors: Olivier L. Tremoulet, Jr., Chidambaram Raghavan
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Patent number: 6019298Abstract: A nozzle for producing an ultrahigh-pressure fluid fan jet is shown and described. In a preferred embodiment, the nozzle has an inner surface defined by a conical bore extending from a first end to a second end, thereby creating an entrance orifice and an exit orifice in the first and second ends, respectively. A wedge-shaped notch extends inward from the second end towards the first end to a sufficient depth such that the shape of the exit orifice is defined by the intersection of the conical bore and the wedge-shaped notch. As pressurized fluid passes through the nozzle and out the exit orifice, the shape of the exit orifice causes the pressurized fluid to exit in the form of a fan jet having a substantially oval cross-section. This fan jet may be swept across a surface to be cleaned thereby selectively removing a layer of material from an underlying surface evenly and completely, without damaging the underlying surface. The fan jet may also be used to cut a fibrous or hard material.Type: GrantFiled: March 6, 1998Date of Patent: February 1, 2000Assignee: Flow International CorporationInventors: Chidambaram Raghavan, Edmund Y. Ting, Olivier L. Tremoulet, Jr., Anton H. Buchberger
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Patent number: 5961053Abstract: A nozzle for producing an ultrahigh-pressure fluid fan jet is shown and described. In a preferred embodiment, the nozzle has an inner surface defined by a conical bore extending from a first end to a second end, thereby creating an entrance orifice and an exit orifice in the first and second ends, respectively. A wedge-shaped notch extends inward from the second end towards the first end to a sufficient depth such that the shape of the exit orifice is defined by the intersection of the conical bore and the wedge-shaped notch. As pressurized fluid passes through the nozzle and out the exit orifice, the shape of the exit orifice causes the pressurized fluid to exit in the form of a fan jet having a substantially oval cross-section. This fan jet may be swept across a surface to be cleaned thereby selectively removing a layer of material from an underlying surface evenly and completely, without damaging the underlying surface. The fan jet may also be used to cut a fibrous or hard material.Type: GrantFiled: June 13, 1996Date of Patent: October 5, 1999Assignee: Flow International CorporationInventors: Chidambaram Raghavan, Edmund Y. Ting, Olivier L. Tremoulet, Jr., Anton H. Buchberger
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Patent number: 5942045Abstract: A method for removing hard coatings from an underlying surface is shown and described. In a preferred embodiment, a nozzle having a particular geometry is used in a high-pressure fluid system to produce an ultrahigh-pressure fluid fan jet. The fan jet is traversed across a surface to be cleaned, thereby removing a layer of material without damaging the underlying surface. The effectiveness of the coating removal is improved by selecting an appropriate power distribution for the fan jet, a standoff distance between the fan jet and the surface to be cleaned, the speed with which the fan jet traverses the surface and the length and diameter of a settling chamber existing upstream of the nozzle.Type: GrantFiled: March 19, 1997Date of Patent: August 24, 1999Assignee: Flow International CorporationInventors: Chidambaram Raghavan, Jeffrey D. Watson, Steven S. Sisson
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Patent number: 5785582Abstract: An improved mixing tube for use in a high-pressure abrasive fluid jet system is shown and described. In a preferred embodiment, the mixing tube is provided by forming a first piece and a second piece, each piece having a length that is substantially equal to the length of the mixing tube. A longitudinal groove is provided in each piece, the longitudinal groove extending from a first end to a second end of each piece. The first and second pieces are coupled together, such that the first and second longitudinal grooves meet to form a bore that extends longitudinally through the length of the mixing tube. Although the first and second pieces may be joined in a variety of ways, in a preferred embodiment, the two pieces are joined by shrink fitting a metal sheath around the outer surface of each piece. The first and second pieces are made of a hard ceramic material, and the longitudinal grooves are formed by grinding the pieces to remove material along their length.Type: GrantFiled: December 22, 1995Date of Patent: July 28, 1998Assignee: Flow International CorporationInventors: Thomas J. Stefanik, Edmund Y. Ting, Chidambaram Raghavan
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Patent number: 5730358Abstract: An improved and tunable ultrahigh-pressure nozzle for use in generating ultrahigh-pressure fluid jets is shown and described. In a preferred embodiment, a nozzle body is provided with a first conical bore that extends from an entrance orifice to an exit orifice, the bore transitioning into a second conical bore that is formed in a seal. The seal is formed to capture a nozzle orifice and position it in the nozzle body adjacent the exit orifice. By selecting the geometry of the nozzle, namely the diameter of the entrance orifice, and an included angle of the first and second conical bores, it is possible to optimize performance of a fluid jet generated by the nozzle for a selected task and operating parameters.Type: GrantFiled: December 22, 1995Date of Patent: March 24, 1998Assignee: Flow International CorporationInventors: Chidambaram Raghavan, Curtis L. Anderson, Richard F. Schmid
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Patent number: 5564469Abstract: A high pressure relief valve for use in a high pressure fluid pump is shown and described. In a preferred embodiment, a valve seat is provided with a tapered hole and with a conduit, the tapered hole and conduit being in fluid communication with each other and with fluid having a variable pressure. A tapered pin having grooves is held in the tapered hole by a control force, or control pressure acting through a plunger. When the pressure of the fluid is sufficiently high to overcome the control force or pressure, the tapered pin is forced to move sufficiently to create an annular clearance between the tapered pin and the tapered hole, thereby allowing pressurized fluid to flow past the pin to an outlet. An outer surface of the valve seat in a region of the tapered pin is tapered in an opposite direction to that of the tapered hole, thereby weakening the valve seat in that region, such that the tapered hole is able to expand and contract as the pressure of the fluid increases and decreases.Type: GrantFiled: December 28, 1994Date of Patent: October 15, 1996Assignee: Flow International CorporationInventors: Olivier L. Tremoulet, Jr., Chidambaram Raghavan, Edmund Y. Ting, Glenn Erichsen
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Patent number: 5512318Abstract: A method for uniformly roughening a surface through use of an ultrahigh-pressure fluid fan jet has been shown and described. In a preferred embodiment, an ultrahigh-pressure fan jet is generated by pressurizing a volume of fluid, and forcing the pressurized fluid through a fan jet nozzle. The fan jet is positioned relative to the surface to be treated at a desired distance, and the fan jet is traversed across the surface at a selected rate to uniformly roughen the surface. In a preferred embodiment, the achieved surface roughness is quantified and compared to a desired surface finish. Operating parameters, such as horsepower and traverse rate, may then be adjusted accordingly to achieve the desired surface finish. By uniformly and completely roughening a surface through use of an ultrahigh-pressure fan jet prior to applying a coating to the roughened surface, adherence between the surface and the coating will be improved.Type: GrantFiled: March 29, 1995Date of Patent: April 30, 1996Assignee: Flow International CorporationInventors: Chidambaram Raghavan, Steven S. Sisson, Richard F. Schmid