Abstract: Both a system and method for cleaning a tow pressure separation vessel of a high pressure polyethylene polymerization plant are provided. The system includes a polytetrafluoroethylene lining that covers the interior surfaces of the vessel, and a cover mounting assembly including an annular clamp for detachably mounting a cover over the vessel. The mounting assembly includes a clamp actuator for quickly securing and releasing the cover with respect to a top rim of the vessel. The vessel is drained of liquid polyethylene and allowed to cool to ambient temperature, thus creating a frozen “skin” of polyethylene around the interior surfaces of the vessel. The clamp actuator releases the cover. The polyethylene skin is peeled off the interior sides the vessel and gathered up at the top to form a neck, thus peeling the polyethylene skin away from the polytetrafluoroethylene lining along with any degraded polymers or other impurities that have accumulated on the interior surfaces of the vessel.

Abstract: Both a system and method for cleaning a low pressure separation vessel of a high pressure polyethylene polymerization plant are provided. The system includes a polytetrafluoroethylene lining that covers the interior surfaces of the vessel, and a cover mounting assembly including an annular clamp for detachably mounting a cover over the vessel. The mounting assembly includes a clamp actuator for quickly securing and releasing the cover with respect to a top rim of the vessel. The vessel is drained of liquid polyethylene and allowed to cool to ambient temperature, thus creating a frozen “skin” of polyethylene around the interior surfaces of the vessel. The clamp actuator releases the cover. The polyethylene skin is peeled off the interior sides the vessel and gathered up at the top to form a neck, thus peeling the polyethylene skin away from the polytetrafluoroethylene lining along with any degraded polymers or other impurities that have accumulated on the interior surfaces of the vessel.

Abstract: Both a system and method for cleaning a low pressure separation vessel of a high pressure polyethylene polymerization plant are provided. The system includes a polytetrafluoroethylene lining that covers the interior surfaces of the vessel, and a cover mounting assembly including an annular clamp for detachably mounting a cover over the vessel. The mounting assembly includes a clamp actuator for quickly securing and releasing the cover with respect to a top rim of the vessel. The vessel is drained of liquid polyethylene and allowed to cool to ambient temperature, thus creating a frozen “skin” of polyethylene around the interior surfaces of the vessel. The clamp actuator releases the cover. The polyethylene skin is peeled off the interior sides the vessel and gathered up at the top to form a neck, thus peeling the polyethylene skin away from the polytetrafluoroethylene lining along with any degraded polymers or other impurities that have accumulated on the interior surfaces of the vessel.

Abstract: Provided is a stirred tank polymerization reactor system having a reactor tank, a stirring assembly including a rotatable shaft that extends through a wall of the tank, and a triple barrier mechanical seal. The mechanical seal includes an outer cylinder mounted in the wall of the tank, an inner cylinder that is rotatable relative to the outer cylinder and connected to the shaft, and first, second, and third fluid barrier seals mounted between the outer and inner cylinders at different positions along the axis of rotation of the inner cylinder. First and second sources of pressurized barrier fluid are connected between the first and second pressure fluid barrier seals and the second and third barrier seals, respectively. The three barrier seals advantageously “step down” the differential pressure experienced by the uppermost barrier seals, substantially reducing mechanical stresses experienced by the annular sealing rings and seats.

Abstract: Disclosed in one aspect is a valve comprising (a) a valve body having a poppet valve chamber with an axis running there through; (b) a seat having a seat sealing surface, and a outer-seat surface, the seat located axially within the poppet valve chamber; and (c) a poppet having a poppet sealing surface, the poppet being located axially within the poppet valve chamber; wherein a poppet-seat interface is created between at least a portion of the seat sealing surface and at least a portion of the poppet sealing surface, the poppet-seat interface being at an angle ? of from 20 to 90° to the axis. In one embodiment the seat is removable, allowing the geometry of at least the poppet head surface and/or the seat inside surface, which defines a fluid flow-path cross-section, to be tailored.

Abstract: Provided is a stirred tank polymerization reactor system having a reactor tank, a stirring assembly including a rotatable shaft that extends through a wall of the tank, and a triple barrier mechanical seal. The mechanical seal includes an outer cylinder mounted in the wall of the tank, an inner cylinder that is rotatable relative to the outer cylinder and connected to the shaft, and first, second, and third fluid barrier seals mounted between the outer and inner cylinders at different positions along the axis of rotation of the inner cylinder. First and second sources of pressurized barrier fluid are connected between the first and second pressure fluid barrier seals and the second and third barrier seals, respectively. The three barrier seals advantageously “step down” the differential pressure experienced by the uppermost barrier seals, substantially reducing mechanical stresses experienced by the annular sealing rings and seats.

Abstract: Systems and methods for separating particles from fluids are provided. The system comprises a vessel with a fluid inlet and a fluid outlet and a baffle assembly located within the vessel. The baffle assembly has a plurality of baffles that can provide a change in direction to fluid entering the vessel thereby separating particles. During shut-down of a polymerization reactor, reaction mixture is discharged to a separation system where polymer particles are removed from the mixture prior to being released into the atmosphere.

Abstract: Both a system and method for cleaning a low pressure separation vessel of a high pressure polyethylene polymerization plant are provided. The system includes a polytetrafluoroethylene lining that covers the interior surfaces of the vessel, and a cover mounting assembly including an annular clamp for detachably mounting a cover over the vessel. The mounting assembly includes a clamp actuator for quickly securing and releasing the cover with respect to a top rim of the vessel. The vessel is drained of liquid polyethylene and allowed to cool to ambient temperature, thus creating a frozen “skin” of polyethylene around the interior surfaces of the vessel. The clamp actuator releases the cover. The polyethylene skin is peeled off the interior sides the vessel and gathered up at the top to form a neck, thus peeling the polyethylene skin away from the polytetrafluoroethylene lining along with any degraded polymers or other impurities that have accumulated on the interior surfaces of the vessel.

Abstract: The invention provides a compressor for use as a secondary compressor for an ethylene polymerization tubular reactor comprising a motor and at least two compressor frames, at least one of the compressor frames being coupled to the motor by means of a contoured diaphragm flexible coupling.

Abstract: A rotary internal combustion engine including a rotary screw compressor for receiving and compressing a mixture of air and fuel, a rotary positive displacement pump for receiving the compressed air and fuel mixture from the rotary screw compressor and pumping the mixture of compressed air and fuel therethrough, the pump having igniting means for igniting the mixture of compressed air and fuel inside of the pump, and a rotary screw expander for receiving the ignited mixture of compressed air and fuel and for expanding the volume of the ignited mixture of air and fuel therethrough.