Patents by Inventor Pradip S. Mehta

Pradip S. Mehta 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).

  • Patent number: 4711581
    Abstract: A rotary processor has enclosed processing passages defined by channels in the rotor and a stationary coaxial closure. At least one processing passage is used as a stabilizing passage and another as a metering passage, whose volume and cross section are less than the stabilizing passage. A feed of plastic or polymeric material enters the stabilizing passage and may be subject to fluctuations or disturbances arising in external upstream equipment or within upstream stages of the processor itself. Substantially all material in the stabilizing passage is diverted through a first transfer passage to an entrance into the metering passage. An adjustable metering (throttling) element allows a controlled first flow of material to be carried downstream through an adjustable gap between this metering element and the bottom of the metering passage. This controlled first flow is discharged for providing material having uniform flow or at least a marked reduction in such fluctuations and disturbances.
    Type: Grant
    Filed: March 4, 1987
    Date of Patent: December 8, 1987
    Assignee: Farrel Corporation
    Inventors: Pradip S. Mehta, Lefteris N. Valsamis, Gary S. Donoian
  • Patent number: 4606646
    Abstract: Novel rotary processors and devolatilizing methods which provide extremely efficient devolatilization of materials, including viscous and visco-elastic materials and which involve a devolatilizing stage including a rotatable element carrying a plurality of annular channels and a stationary element providing a coaxial closure surface operationally arranged with the channels to provide enclosed processing passages. Each passage of the devolatilizing stage includes inlet means, outlet means and a channel blocking member all associated with the stationary element and arranged and adapted so that material fed to the inlet can be carried forward by the rotatable channel walls to the blocking member for discharge from the passage. The passages are interconnected by material to transfer grooves formed in the closure surface and operationally communicate with a vacuum source to provide a highly efficient devolatilizing stage.
    Type: Grant
    Filed: March 8, 1985
    Date of Patent: August 19, 1986
    Assignee: USM Corporation
    Inventors: Pradip S. Mehta, Lefteris N. Valsamis, Zehev Tadmor
  • Patent number: 4582432
    Abstract: Rotary processors and methods for mixing a low viscosity liquid with a viscous material while controlling plugging of the means for introducing low viscosity liquid to the processor. Viscous material is introduced to a mixing rotary processor comprising at least one annular channel carried by a rotor and enclosed by a housing to form a mixing passage. The material is dragged forward by the rotating channel walls from the passage inlet past a spreader as films on the channel walls, forming a void downstream of the spreader between the films. Low viscosity liquid is sprayed from a point within the void to be deposited on and carried downstream with the films of material and to be mixed with material collected at a passage end wall.In one embodiment, pressure sealing means permits spraying into a saturated vapor zone in the void so that liquid vaporizes and is condensed onto the films as well distributed fine droplets.
    Type: Grant
    Filed: December 20, 1984
    Date of Patent: April 15, 1986
    Assignee: USM Corporation
    Inventor: Pradip S. Mehta
  • Patent number: 4582433
    Abstract: Rotary processors and methods for purifying a viscous liquid material by liquid-liquid extraction. Material is introduced to an extracting apparatus including a mixing rotary processor comprising at least one annular channel carried by a rotor and enclosed by a housing to form a mixing passage. The material is dragged forward by the rotating channel from the passage inlet past a blocking member. Solvent introduced to the passage, such as by spray means, is carried downstream with the material and dispersed in material collected at a passage end wall. In one embodiment the blocking member comprises a spreader which spreads the material as films on the channel walls. In another embodiment, sparging means sparges solvent into a pool of the material collected upstream of the blocking member. Separation of the solvent from the material may involve rotary devolatilizing or phase separating processors, which may be arranged with the mixing processor for cocurrent or countercurrent, multi-stage series operation.
    Type: Grant
    Filed: December 20, 1984
    Date of Patent: April 15, 1986
    Assignee: USM Corporation
    Inventor: Pradip S. Mehta
  • Patent number: 4549810
    Abstract: Apparatus and methods for physically separating a heterogeneous mixture of immiscible liquids utilizing the difference in the viscosities of the components. At least one moveable surface is enclosed by at least one stationary surface to form a processing passage. Viscous-drag-induced momentum is transferred preferentially from the moving surface(s) to the more viscous component of the mixture, moving it downstream toward a collecting and pressurizing obstructing member. The resulting pressure "squeezes" the less viscous droplets upstream to separate from the collected material and drain from the passage through a drainage opening.In a preferred embodiment, an annular channel rotates within a housing, dragging the mixture from an inlet to an obstructing member extending into the passage near an outlet. The separated less viscous component drains from a drainage opening in the housing, while the more viscous component is discharged through the outlet.
    Type: Grant
    Filed: December 20, 1984
    Date of Patent: October 29, 1985
    Assignee: USM Corporation
    Inventor: Pradip S. Mehta
  • Patent number: 4529320
    Abstract: Novel rotary processors and devolatilizing methods which provide extremely efficient devolatilization of materials, including viscous and visco-elastic materials and which involve a devolatilizing stage including a rotatable element carrying a plurality of annular channels and a stationary element providing a coaxial closure surface operationally arranged with the channels to provide enclosed processing passages. Each passage of the devolatilizing stage includes inlet means, outlet means and a channel blocking member all associated with the stationary element and arranged and adapted so that material fed to the inlet can be carried forward by the rotatable channel walls to the blocking member for discharge from the passage. The passages are interconnected by material to transfer grooves formed in the closure surface and operationally communicate with a vacuum source to provide a highly efficient devolatilizing stage.
    Type: Grant
    Filed: September 14, 1983
    Date of Patent: July 16, 1985
    Assignee: USM Corporation
    Inventors: Pradip S. Mehta, Lefteris N. Valsamis, Zehev Tadmor
  • Patent number: 4529478
    Abstract: Novel rotary processors which involve a devolatilizing stage including a rotatable element carrying a plurality of annular channels and a stationary element providing a coaxial closure surface operationally arranged with the channels to provide enclosed processing passages. Each passage of the devolatilizing stage includes inlet means, outlet means and a channel blocking member all associated with the stationary element and arranged and adapted so that material fed to the inlet can be carried forward by the rotatable channel walls to the blocking member for discharge from the passage. The passages are interconnected by material transfer grooves formed in the closure surface.The rotary processors of this invention include a novel vacuum system to evacuate the devolatilizing stage.
    Type: Grant
    Filed: September 14, 1983
    Date of Patent: July 16, 1985
    Assignee: USM Corporation
    Inventors: Pradip S. Mehta, Lefteris N. Valsamis
  • Patent number: 4527900
    Abstract: Novel rotary processors including sealing means to control leakage of pressure and/or material between processing passages which are maintained at significantly different pressure levels. The processors comprise a rotatable element carrying a plurality of annular channels and a stationary element providing a coaxial closure surface operationally arranged with the channels to provide enclosed processing passages. Each passage includes inlet means, outlet means and a channel blocking member all associated with the stationary element and arranged and adapted so that viscous material fed to the inlet can be carried forward by the rotatable channel walls to the blocking member for discharge from the passage. The passages are interconnected by material transfer grooves formed in the closure surface.
    Type: Grant
    Filed: September 14, 1983
    Date of Patent: July 9, 1985
    Assignee: USM Corporation
    Inventors: Pradip S. Mehta, Lefteris N. Valsamis
  • Patent number: 4480923
    Abstract: Novel rotary processors including sealing means to control leakage of pressure and/or material between processing passages which are maintained at significantly different pressure levels. The processors comprise a rotatable element carrying a plurality of annular channels and a stationary element providing a coaxial closure surface operationally arranged with the channels to provide enclosed processing passages. Each passage includes inlet means, outlet means and a channel blocking member all associated with the stationary element and arranged and adapted so that material fed to the inlet can be carried forward by the rotatable channel walls to the blocking member for discharge from the passage. The passages are interconnected by material transfer grooves formed in the closure surface.
    Type: Grant
    Filed: September 14, 1983
    Date of Patent: November 6, 1984
    Assignee: USM Corporation
    Inventor: Pradip S. Mehta