Abstract: A plurality of cords of heat resistant material are disposed adjacent to one another in a plurality of layers. A heat resistant tape material having an adhesive formed thereon in a pair of beads is wrapped around the center portions of the cord members so as to form a pair of free hanging curtain sections effective to block gas flows in a heat treatment furnace or the like. The adhesive is also heat resistant, and the use of a tape to form this curtain assembly enables the same to be independent of mounting hardware such as clamped mounting plates. The vertical position of the curtain assembly may be adjustable so as to compensate for wear during use.

Abstract: Apparatus for providing a gas flow only for a predetermined time period includes a normally pressurized closed valve in a gas line and a timed valve adapted to remove gas pressure from the normally pressurized closed valve thereby opening the same. The length of time during which such pressure is removed is controlled by the period of time necessary to exhaust pressure in a stage of the timed valve through a variable flow restrictor and upon expiration of such time period, pressure is reapplied to the line valve thereby closing the same. The flow of gas is thus permitted to continue for a predetermined time period following which the gas flow is terminated and relatively simple, conventional valve devices may be utilized to reliably control the gas flow.

Abstract: A gas scavenger system is disclosed for use particularly with anesthetic administering equipment utilizing a demand valve for providing anesthetic gas to the patient. The gas scavenger system includes a collection manifold that collects the waste gases as they leave the normal exhaust ports of the demand valve. A flexible tubing means then carries those collected gases to a surge chamber prior to eventual discharge into a vacuum system. The surge chamber provides an interface between the vacuum system and the collection manifold and is connected to the vacuum system through a predetermined sized orifice which limits the flow to the vacuum system to a maximum known flow. The surge chamber normally allows continuous flow through the orifice to the vacuum system but is sized to accumulate an excess of flow from the collection manifold under abnormal conditions such as is occasioned when a patient coughs to allow time to remove the gases through the orifice and thus to prevent leakage to atmosphere.

Abstract: A workpiece transporting apparatus particularly adapted to allow a rapid transfer of workpieces through a sealable opening between opposite sides of a wall, and thus rapid loading and unloading of vacuum processing or other sealable chambers. In a preferred embodiment, the apparatus employs a walking beam accumulator which comprises a first frame having a beam or rack with a series of locations for supporting a group of substrate holders, and a similar second frame mounted for rotation on an eccentric so that each holder supported by the first frame is removed, moved forward, and placed into an adjacent location on the first frame. The apparatus also employs a mechanism for relatively moving the walking beam accumulator and a workpiece receiver between a first position in which the wall opening can be sealed and a second position in which workpieces can be transferred between the accumulator and the receiver via the opening. In a preferred embodiment, the receiver is a rotatable drum inside a process chamber.

Abstract: A tunnel refrigeration device includes frame members mounted substantially adjacent to an endless conveyor belt which is utilized to pass products to be refrigerated through the tunnel. The frame members are provided with apertures therein and fan means are mounted in one or more of the apertures so as to pass the tunnel atmosphere into the space between the upper and lower runs of the conveyor belt. Apertures are juxtaposed with each frame mounted fan to enable the tunnel atmosphere passed into this space to be removed therefrom and recirculated upwardly in the tunnel by means of the top mounted fans. Refrigeration is provided to the underside of products on the conveyor belt and the effective capacity of the tunnel may be increased by increasing the capacity of the top mounted fans.

Abstract: A product such as ground meat is efficiently chilled in a blender device having an open top. Liquid carbon dioxide is introduced into the blender at a location below the surface of the product to thereby form solid and gaseous CO.sub.2. Mixing elements such as a ribbon screw or the like are operated to pass the product in a countercurrent relation to the carbon dioxide introduced into the blender thereby chilling the product and causing the resulting CO.sub.2 gas to rise along one wall of the blender. Deflector means are provided along such wall to direct the rising vapor toward an exhaust plenum located above the open top of the blender.

Abstract: A chamber such as a curing oven or drier is inerted during the curing of solvent borne resin coatings with the solvent vapor formed therein being withdrawn together with inert gas at a substantially constant flow rate. The withdrawn gas stream is supplied to a condensation unit to enable recovery of solvent and the noncondensed gas discharged from the condensation unit is returned to the oven at a flow rate which may be varied so as to maintain a material balance with respect to the oven atmosphere. Appropriate adjustments are made in response to changes occurring in the oven solvent vapor and/or oxygen concentration without disturbing the material balance mentioned above while the oven atmosphere is withdrawn at a substantially constant flow rate. A plurality of ovens may be connected to a single condensation unit and upon detecting undesired conditions such as excessive oxygen levels in one oven, the same may be separately isolated from the condensation unit.

Abstract: Tobacco is expanded by cooling the same to a temperature of about 30.degree. F. or less and subjecting such cooled tobacco to a subatmospheric pressure in a vessel. CO.sub.2 gas is then introduced into the vessel and contacts the cooled tobacco to impregnate the tobacco with CO.sub.2 gas as pressure in the vessel is brought to substantially atmospheric pressure. Subsequently, the cooled CO.sub.2 impregnated tobacco is subjected to conditions whereby the CO.sub.2 in the tobacco is removed and the tobacco is expanded. Typically, the CO.sub.2 impregnated tobacco is introduced into an expansion tower wherein it is heated to increase the volume of the CO.sub.2 and to expand the tobacco in size.

Abstract: A snow horn device for dispensing carbon dioxide snow in the form of a ribbon of substantially uniform width includes a conduit into which liquid CO.sub.2 is expanded to form solid and gaseous carbon dioxide which in turn is directed as a stream into a curved horn section of increasing, rectangular cross sectional area. The gaseous and solid CO.sub.2 stream is deflected to the outer curved portion of the horn section, and ambient atmosphere is introduced therein to create a pressure differential that causes solid CO.sub.2 to be spread evenly along the outer curved section. Alternately, the inner and outer curved horn sections are warmed by a flow of liquid CO.sub.2 which prevents solid CO.sub.2 from sticking to the curved surfaces. Solid carbon dioxide is discharged from the outlet of the horn section onto a moving surface in the form of a ribbon having a width approximately equal to the width of the horn section and at a uniform depth.

Abstract: Ferrous material such as tool steel is annealed in a batch or continuous furnace into which inward leakage of an ambient oxidant occurs. The hot zone is heated to a temperature of about 1250.degree.-1650.degree. or higher and the material passed therethrough under a nitrogen based atmosphere comprised of nitrogen, methane and a minor addition of propane with nitrogen comprising approximately 90% of the hot zone atmosphere. Propane reacts with the oxidants to form a relatively active form of methane which, together with methane introduced as such into the hot zone, reacts effectively at low temperatures (1400.degree. F. or below) to avoid both decarburization and sooting. The hot zone atmosphere evinces considerably lesser tendencies to decarburize or soot than atmospheres formed only of N.sub.2 --C.sub.3 H.sub.8 mixtures and is considerably more reactive than atmospheres formed only of N.sub.2 --CH.sub.4 mixtures at these lower temperatures.