Abstract: A compact, inexpensive self-regulating heater for heating a surface to a prescribed temperature. A first embodiment comprises a PTC ceramic heating element which is conductively bonded directly to heavy copper (or brass) electrodes, which conduct both heat and electricity with low resistance and present a smooth, extended heat transfer surface. At least one of the electrodes (on at least one side of the PTC element) is configured for maximum surface area in contact with the article being heated. The preferred methods of manufacture of this invention result in the electrodes being prestressed in tension while the ceramic element is prestressed in compression at room temperature. Upon heating, during use, these stresses tend to disappear as the electrodes expand.

Abstract: A process for separating a mixture of gases by selective adsorption, in which pressure swing is used to induce both desorption and the flow of gas through at least one simulated moving chromatographic column.

Abstract: The invention disclosed is a method and apparatus for moving-bed or simulated-moving-bed continuous chromatographic separation, in which some solvent is removed from the elution liquid at a point between the two zones where fractionation takes place. The resulting product streams have higher recovery and purity than without such solvent removal.

Abstract: A method and preferred apparatus for expanding moisture containing tobacco. Tobacco is very rapidly heated by a stream of heated gas, by contacting a high speed downdraft flow of said gas with said tobacco while said tobacco is in transit on a gas porous conveyer. The conveyer is preferably configured as a cylindrical drum with a gas porous cylindrical surface, rotating about its axis.

Abstract: Methods and apparatus for treating a continuous flow of tobacco under pressure include introducing said tobacco to a pressurized chamber through an entrance lock device, impregnating said tobacco with a pressurized gas or its liquid phase within said chamber, and discharging said impregnated tobacco from said chamber through an exit lock device. Liquid impregnant may be applied as a fine spray within said chamber, and subsequent expansion of said tobacco may be performed by decompression, heating, or by decompression and heating in combination.

Abstract: The present invention relates to a method for increasing the filling power of tobacco by intense convection heating of moistened, and possibly frozen, tobacco in a gas with steam as its major component.

Abstract: Method and apparatus for recovering, as liquid, condensable vapor contained in a gas stream by refrigerating the gas stream by injecting the liquified phase of an inert gas, such as nitrogen, mixing the combined gas stream and liquified inert has, and separating the condensed condensable vapor from the remaining gas stream and inert gas.

Abstract: Tobacco impregnated with solid carbon dioxide is heated in a chamber to expand the same by sublimation of solid CO.sub.2 and expulsion of CO.sub.2 gas from the tobacco. The expanded tobacco is separated from the internal atmosphere of the expansion device and the tobacco is discharged through an outlet through which gas flows are substantially precluded. The evolved CO.sub.2 gas and other volatile components are removed from the chamber and a portion of the removed gas is heated and returned to the chamber as the expansion medium. The necessity for external steam is avoided as an atmosphere of high thermal diffusivity is maintained in the expansion chamber by precluding the entry of ambient air.

Abstract: Tobacco impregnated with solid carbon dioxide is heated in a chamber to expand the same by sublimation of solid CO.sub.2 and expulsion of CO.sub.2 gas from the tobacco. The expanded tobacco is separated from the internal atmosphere of the expansion device and the tobacco is discharged through an outlet through which gas flows are substantially precluded. The evolved CO.sub.2 gas and other volatile components are removed from the chamber and a portion of the removed gas is heated and returned to the chamber as the expansion medium. The necessity for external steam is avoided as an atmosphere of high thermal diffusivity is maintained in the expansion chamber by precluding the entry of ambient air.

Abstract: The refrigeration available in a liquefied gas is utilized to refrigerate a fluid having a boiling point above the boiling point of the liquefied gas which is sprayed into an endless conduit such that the liquefied gas is vaporized. The resulting thermal currents and momentum of the spray are effective to provide the motive power for circulating the gas throughout the conduit and into indirect heat exchange with the fluid to be refrigerated. The temperature of heat exchange means in the vicinity of the location at which the fluid is introduced into such indirect heat exchange may be regulated by controlling the magnitude of the gas flow throughout the conduit to thereby avoid freezing of components of such fluid. The use of shaft power (such as a fan or blower) for circulating the gas flow throughout the conduit is avoided and the utilization of refrigeration available in the liquefied gas is improved accordingly.

Abstract: A chamber is isolated from ambient atmosphere by supplying a flow of inert gas to the entrance and/or exit of the chamber such as an oven for curing solvent borne resin coatings on a material passed therethrough. The inert gas is supplied at a substantially constant mass flow rate through an orifice which may be adjusted in opening or direction so as to enable the momentum of discharged inert gas to be controlled. A flow of gas is exhausted exteriorly of but in the vicinity of the chamber exit or entrance and the oxygen content of such flow is sensed. The sensed oxygen value is compared with a predetermined value and the difference is utilized to adjust the orifice to either increase or decrease the momentum of inert gas discharged therefrom. In this manner atmospheric oxygen is precluded from entering the chamber while only the amount (flow) of inert gas necessary to block such oxygen is utilized thereby minimizing the loss of inert gas from the chamber to ambient.

Abstract: methods and apparatus for recovering hydrocarbon solvents evaporated during the curing of solvent borne coatings in an oven include supplying an inert gas to the vicinity of the oven entrance and exit to substantially exclude oxygen therefrom while safely maintaining a solvent vapor partial pressure within the oven of at least 75% of the lower explosive limit of such vapor in air. The oven atmosphere is exhausted and passed to a condenser to enable recovery of at least 85% of the solvent vapor as a liquid. Preferably, condensation of the solvent vapor is effected by heat exchange with liquid nitrogen which is effective to vaporize the liquid nitrogen to produce nitrogen gas which may then be utilized to exclude oxygen from and to inert the oven.

Abstract: A method and apparatus for inerting the atmosphere adjacent a moving product surface such as a resin bearing web material includes passing the product through a device having entrance and exit tunnels and a treatment chamber therebetween at speeds up to 1,000 ft. per minute or greater. An inert gas flow is introduced into the entrance tunnel at a velocity relative to the velocity of the moving product surface such that a turbulent condition is established in the boundary layer of air dragged into the entrance tunnel by the moving product. Turbulence in the boundary layer promotes the rapid diffusion of atmospheric oxygen upwardly away from the moving product surface. The inert gas flow is of a magnitude sufficient to maintain oxygen concentration at the tunnel entrance at less than 20.8% thereby enabling such diffusion of oxygen. For slowly moving product surfaces, a high velocity cross flow inert gas stream is provided to establish a resultant relative velocity capable of generating the requisite turbulence.

Abstract: A coupling device is disclosed for rapidly and ecnomically mechanically joining a pair of elongated structural elements such as reinforcing bars in the field. The cylindrical couplingdevice includes an outer annular chamber containing porous substance which can be made to react exothermically, such as a mixture of aluminum and iron oxide powder which releases molten material, e.g. iron, upon being activated. The mass of exothermic material includes air in a quantity determined by the material's porosity when packed into the outer annular chamber. When the exothermic material is made to react, it heats the contained air and causes it to expand and act as a propellant, which causes molten iron from the exotheric reaction to be propelled from the outer chamber into an interior cylindrical chamber or chambers which contain the ends of the reinforcing bars.

Abstract: Annular coupling members are disclosed for welding together sections of pipe used, for example, in the construction of oil pipelines, such annular coupling members containing annular bodies of exothermic materials such as "Thermite" material, and upon being ignited being capable of producing true welding of the interfaces between the coupler and a pair of pipes welded thereto or between the two pipes directly. These interfaces are beveled to accommodate variations in the diameters of the pipe sections so that any such variations will not adversely affect a true weld at these interfaces. Since the annular exothermic bodies are positioned adjacent the interfaces and interior of the annular coupler, the vast quantities of heat generated by igniting the "Thermite" bodies are directly utilized to form true welding of the interfaces, rather than being lost in varying degree to the material of separate reaction vessels, sprues, etc., as in prior art techniques.