Abstract: A particle blast apparatus includes a hopper assembly, which is mechanically isolated from the rest of the particle blast system. Energy is imparted to the hopper by an impulse assembly, which preferably is mounted directly to the hopper. The hopper is mounted to the apparatus on a slide assembly, which allows the hopper to be moved to a second position at which particles may be discharged from the hopper exit away from the particle feeder.

Abstract: A particle blast system includes a feeder assembly having a rotor with a plurality of pockets formed in the peripheral surface. The transport gas flowpath includes the pockets, such that substantially all transport gas flows through the pockets. The seal adjacent the peripheral surface is actuated by the transport gas pressure to urge its sealing surface against the rotor's peripheral surface. At start up, there is no substantial pressure between the seal and the rotor, reducing start up torque requirements.

Abstract: A blast nozzle formed of a non-conductive material includes electrically conductive paths embedded therein to keep the build up of static electricity below an undesirable level. Stainless steel rods extend the length of the blast nozzle, providing a continuous electrical path.

Abstract: A particle blast apparatus includes a hopper assembly, which is mechanically isolated from the rest of the particle blast system. Energy is imparted to the hopper by an impulse assembly, which preferably is mounted directly to the hopper. The hopper is mounted to the apparatus on a slide assembly, which allows the hopper to be moved to a second position at which particles may be discharged from the hopper exit away from the particle feeder.

Abstract: A particle blast system includes a feeder assembly having a rotor with a plurality of pockets formed in the peripheral surface. The transport gas flowpath includes the pockets, such that substantially all transport gas flows through the pockets. The seal adjacent the peripheral surface is actuated by the transport gas pressure to urge its sealing surface against the rotor's peripheral surface. At start up, there is no substantial pressure between the seal and the rotor, reducing start up torque requirements.

Abstract: A particle blast apparatus includes a hopper assembly which is mechanically isolated from the rest of the particle blast system. Energy is imparted to the hopper by an impulse assembly, which preferably is mounted directly to the hopper. The hopper is mounted to the apparatus on a slide assembly which allows the hopper to be moved to a second position at which particles may be discharged from the hopper exit away from the particle feeder.

Abstract: An entrained particle flow turning device capable of turning entrained particle fluid flow about an abrupt turn without significant particle size and mass degradation provides significant improvement as part of a complete particle blast system. The turning base allows for preservation of independent particle mass during fluid transportation through a delivery hose ending with passage into a blast nozzle through an abrupt angular change in particle direction. The turning base allows access and confined areas for preferred ergonomic characteristics.

Abstract: A feeder for transporting particles, such as carbon dioxide pellets, includes a container for receiving particles and a suction nozzle having an inlet end disposed adjacent a discharge area of the container. The nozzle is configured generally as a pipe having a circular cross-sectional area. The nozzle is reciprocally carried by the feeder so that the inlet end may be moved into and away from the particles to prevent the particles from clogging. The container bottom is generally shaped as a chute to direct/move the particles toward the discharge area. A vibrator may be used to assist in the movement of the particles. The nozzle may be reciprocated manually or automatically. Alternatively, the nozzle may be stationary and a mechanical assist included to move the particles toward the discharge area.

Abstract: A thrust balanced turn base for changing the direction of a fluid flow containing entrained abrasive media is provided. The turn base includes an elongated member having an inlet for the fluid flow with the entrained abrasive media. The turn base further includes a first internal passageway that extends in a downstream direction from the inlet. The first passageway includes a first throat, a converging portion between the inlet and the throat, a diverging portion extending downstream from the throat, an additional converging portion downstream from the diverging portion, a turning portion downstream from the additional converging portion that converges to a second throat and that leads to a nozzle that conducts the fluid flow containing the entrained abrasive media in an angled direction relative to the long axis of the turn base.

Abstract: A convergent-divergent Single/Multiple Expansion wave contour wall and wave Reflection solid wall Nozzle (S/MERN) for use with particle blast systems is provided which includes a single contoured converging-diverging wall opposing a generally flat, solid wall disposed generally parallel to the direction of the jet flow. The transition from a circular delivery hose to the rectangular throat of the S/MERN nozzle is preferably in only one dimension, with the distance between the side support walls being substantially the same as the diameter of the delivery hose. The S/MERN nozzle relies on reflection from the flat, solid wall for Mach wave expansions, rather than reflections of opposing expansion waves as in conventional nozzles.

Abstract: A method for removing a surface coating by impinging an area of impingement of the surface coating with photon energy while simultaneously impinging the area of impingement with a cryogenic particle blast flow.

Abstract: There is provided a method and apparatus for practicing carbon dioxide particle blasting utilizing dense carbon dioxide pellets which have been formed by converting the solid carbon dioxide into liquid, flowing that liquid within a plurality of die openings, and transforming the liquid back into the solid phase while still within the die opening. This method includes the formation of a carbon dioxide cake within a snow barrel, urging the carbon dioxide cake against an upstream surface of a die plate having a plurality of die openings with such pressure such that the carbon dioxide becomes liquified within or adjacent the entrance of the die opening due to the pressure, responding as a super viscous liquid, and flowing within a portion of the respective die openings as a liquid. Along the length of the die openings, the liquid changes phase back to the solid state, while the die openings maintain compression (accompanying the back pressure) on the CO.sub.2 to create pellets having a high density.

Abstract: A method is provided for removing material from a structure having at least one layer of material formed on a substrate. The method includes the steps of irradiating a target area of a structure with radiant energy sufficient to break or weaken chemical bonds in the material, and impinging the target area with a particle stream to remove the pyrolyzed material from the structure. The method may be implemented by a system comprising a housing having a window; a radiant energy source mounted in the housing for irradiating the target area of the structure with the radiant energy; and a nozzle mounted to the exterior of the housing for directing the stream of particles at the target area.

Abstract: There is provided a method and apparatus for practicing carbon dioxide particle blasting utilizing dense carbon dioxide pellets which have been formed by converting the solid carbon dioxide into liquid, flowing that liquid within a plurality of die openings, and transforming the liquid back into the solid phase while still within the die opening. This method includes the formation of a carbon dioxide cake within a snow barrel, urging the carbon dioxide cake against an upstream surface of a die plate having a plurality of die openings with such pressure such that the carbon dioxide becomes liquified within or adjacent the entrance of the die opening due to the pressure, responding as a super viscous liquid, and flowing within a portion of the respective die openings as a liquid. Along the length of the die openings, the liquid changes phase back to the solid state, while the die openings maintain compression (accompanying the back pressure) on the CO.sub.2 to create pellets having a high density.

Abstract: This invention is directed to a flow diverter valve for directing a flow of high pressure transport gas with carbon dioxide pellets entrained therein from a single inlet to a selected one of a plurality of outlets. The flow diverter valve includes a system of face seals and shaft seals adjacent the inlet and outlet ends in order to prevent the leakage of high pressure gas from the flow path.

Abstract: An improved particle blast cleaning apparatus and process featuring sublimable pellets as the particulate media is described as having a source of sublimable pellets, a housing defining an internal cavity having spaced pellet receiving and discharge stations, and a radial transport rotor for transporting the pellets from the receiving station to the discharge station. The radial transport rotor further includes a plurality of transport cavities each being formed in the circumferential surface of the radial transport rotor to receive the pellets for radial transport between the receiving and discharge station. The receiving station is in communication with the source of sublimable pellets, and has a mechanically assisted flow of the pellets to the transport cavities. Also included is a discharge nozzle and a high pressure transport gas source for conveying the pellets from the discharge station to the discharge nozzle.

Abstract: The present invention includes a method for deflashing unwanted material from manufactured articles and more particularly a method for deflashing rigid reaction injection molded articles The method includes the steps of providing a continuous flow of frozen pellets, providing a workpiece having flashing, directing the flow of frozen pellets at the flashing and the workpiece, and impacting the flashing and the workpiece with the frozen pellets.

Abstract: A sound attenuating supersonic nozzle has an exit to throat ratio in the range of 2.5 to 6.0, with longitudinal grooves formed in the interior wall of the supersonic passageway of the nozzle body. A shield is disposed about the exterior surface of the nozzle body, forming an exit cavity and an exit opening, and has a gill cavity through which auxiliary air flows into the exit cavity and mixes with the supersonic flow.

Abstract: A high efficiency phase change nozzle has a body with primary orifices, a pilot nozzle extends upstream from the body and has a pilot orifice and central cavity through which a pilot flow of liquid is flashed to the solid state, cooling the pilot nozzle, thereby precooling the liquid before it flows through the primary orifices. An exit nozzle, in conjunction with a housing, assists in continuing the phase change of the mixture exiting the primary orifices and with dispersing the mixture into the downstream cavity.

Abstract: An improved particle blast cleaning apparatus and process featuring sublimable pellets as the particulate media is described as having a source of sublimable pellets, a housing defining an internal cavity having spaced pellet receiving and discharge stations, and a radial transport rotor for transporting the pellets from the receiving station to the discharge station. The radial transport rotor further includes a plurality of transport cavities each being formed in the circumferential surface of the radial transport rotor to receive the pellets for radial transport between the receiving and discharge station. The receiving station is in communication with the source of sublimable pellets, and has a mechanically assisted flow of the pellets to the transport cavities. Also included is a discharge nozzle and a high pressure transport gas source for conveying the pellets from the discharge station to the discharge nozzle.