Abstract: Apparatus and method for producing and metering dry ice pellets and particles selectively from the same apparatus with out modification, by appropriate reversal of a production wheel and accompanying selection of dry ice in the form of block or of pellets for a supply to the production wheel.

Abstract: Apparatus and method for producing and metering dry ice pellets and particles selectively from the same apparatus with ut modification, by appropriate reversal of a production wheel and accompanying selection of dry ice in the form of block or of pellets for a supply to the production wheel.

Abstract: Apparatus and method for producing and metering dry ice pellets and particles selectively from the same apparatus without modification, by appropriate reversal of a production wheel and accompanying selection of dry ice in the form of block or of pellets for a supply to the production wheel.

Abstract: A hand-held blasting gun for use in dry ice blasting for cleaning purposes. A handle and a nozzle mount are pivotally joined so a nozzle on the nozzle mount can be adjustably directed relative to the handle. A flexible hose is fitted in the gun, extending from the end of the handle to the nozzle so as to send without kinking.

Abstract: Apparatus to prepare an airstream laden with particles of solid dry ice. A rotor has passages which sequentially pass a source of particles and a source of air under pressure to prepare the airstream and send it to a nozzle. The rotor is held between pads whose force against the rotor is a function of air supply pressure. The speed of the rotor and of the particle feed are controllable, and the air feed persists after particle feed has stopped for a period of time sufficient to clear particles from the rotor.

Abstract: A granulator and delivery system for sublimable CO.sub.2 granules has working edges rotatably supported for defining a cutting surface; a driver for powering the working edges; a feeder for advancing solid CO.sub.2 into contact with the working edges, the working edges removing the granules from the solid CO.sub.

Abstract: Apparatus for enhancing the feeding of particles includes a hopper having a central axis, walls of the hopper being concentric with the hopper axis above an outlet of the hopper; a sensor for sensing a desired flow of particles from the hopper; a shaft rotatably mounted on the hopper axis; a paddle connected to the shaft and extending from approximately 0.125 inch to approximately 0.250 inch from at least a lower portion of an inside surface wall of the hopper, the shaft being rotated at approximately 1 radian per second in response to a drive signal; the drive signal being momentarily activated in the presence of an external activate signal when the flow of particles falls below the desired rate, the drive signal being active for a period of time sufficient to cause the paddle to move through an angle of about 90.degree. about the hopper axis. The paddle is mechanically agitated during feeding of the particles, the paddle vibrating only during activation of the external signal, with a displacement of from 0.

Abstract: Disclosed is an improved pelletizer and delivery system for hygroscopic and deliquescent materials, pellets being formed by a rotary extrusion mechanism that receives the material in the form of snow from a snow chamber, the system having a pair of scraper members for preventing undesired snow build-up on inside walls of the snow chamber, the scraper members operating in a scissors manner for preventing snow build-up on the scraper members. Carbon dioxide gas from the snow chamber can be used for pressurizing a pellet collector that is located under the extrusion mechanism for smoothly and gently feeding the pellets at least 15 feet horizontally to a receiving hopper, the gas pressure within the collector also enabling delivery of the pellets several feet above the bottom of the collector. The pellets can be delivered in excess of 150 feet horizontally from the collector.

Abstract: A system (10) for delivering a cold particulate material (14) has a closed storage hopper (12) for the material, the hopper having a bottom hopper outlet (16); a venturi feeder (22) having a material inlet (20) for feeding the material, a material conduit (26) to a remote nozzle (30), and a gas inlet (24); a hopper passage (18) connecting the hopper outlet to the feeder material inlet; a gas feed valve (33), the gas feed valve being openable in response to a feed signal (40) for activating the feeder and a blast conduit to the nozzle; a heater (50) in the blast conduit for limiting cooling of a workpiece without adversely heating the material; and a comminutor (52) in the material line proximate the nozzle for delivery of the material at reduced particle size to the nozzle for increased blasting effectiveness.

Abstract: A furnace containing a burner, supplied by fuel to be ignited at the burner, in the presence of air, is provided with a viewing duct for viewing the flame and means for detecting the radiation intensity at a plurality of different wavelengths of the radiation spectrum. The output from the detector is amplified and integrated and a signal representing the ratio of intensities at the selected wavelengths is applied to an indicator to indicate fuel-air ratio and also is applied to control means for the fuel flow or the air flow, or both, to control the fuel-air ratio at the burner and to maintain it substantially constant at a desired value. This can be done at more than one burner, providing balanced furnace operation. With this balanced furnace, there is improved firing efficiency, resulting in fuel saving and lowered pollution emissions. A computer type master controller can be used to correlate the fuel-air ratios for the individual burners.