Abstract: The threaded connection between a graphite shaft and a metal shaft, such as is used to drive a rotating nozzle in the refining of aluminum, is strengthened by coating the graphite surface that contact the flange portion of the metal shaft prior to the fastening of said shafts together. The coating of said graphite shaft serves to greatly strengthen the threaded connection and the ability of said connection to transmit driving torque from the metal shaft to the graphite shaft.

Abstract: In air separation and other gas separations employing pressure swing adsorption technology, reduced cycle times are achieved by an advantageous combination of simultaneous processing steps. The repressurization step in which the upper adsorption pressure is reached in each adsorbent bed is carried out while simultaneously withdrawing product gas from that bed. Following cocurrent depressurization steps in which released void space gas is used for pressure equalization and provide purge gas purposes, each bed, in turn, is further cocurrently depressurized, and the released gas is used for pressure equalization purposes, while the bed is simultaneously being countercurrently depressurized. This latter countercurrent depressurization is then continued to a lower desorption pressure is reached, after which the bed is partially repressurized by pressure equalization, before being further repressurized to upper adsorption pressure with simultaneous withdrawal of product as the next processing cycle is begun.

Abstract: In a pressure swing adsorption system for the supply of enriched oxygen to a variable demand wastewater treatment system, the oxygen product to feed air ratio is increased during periods of reduced oxygen demand, with the enriched oxygen being supplied to the wastewater treatment system at lower purity levels during such periods of reduced demand than the purity levels supplied under maximum demand conditions. Operation in this manner enables oxygen recovery to be enhanced and the power requirements to be reduced under such variable demand conditions.

Abstract: A probe for measuring hydrogen in aluminum melts includes straight inner and outer tubes, the latter having upper and lower plugs and a ceramic fiber sleeve in contact with said upper plug, a straight, ceramic blanketed third tube surrounding said plugs and preventing melt from passing therethrough.

Abstract: Iso-butane is separated from normal butane in a pressure swing adsorption system of at least three adsorbent beds, each adapted to selectively adsorb normal butane from a mixture thereof with iso-butane. The adsorption front of normal butane formed in each adsorbent bed upon the passage of the feed gas mixture thereto is moved through the bed to an extent enhancing the utilization of the adsorptive capacity thereof. By combinations of depressurization and repressurization together with purge, desirable product purity levels are obtained, while the cost of adsorbent equipment and of operation are reduced to the extent possible consistent with the purity requirements of a given application.

Abstract: A feed gas is passed to a pressure swing adsorption system, each bed of which undergoes a processing cycle that includes (1) pressurization (2) copurge at upper adsorption pressure, (3) countercurrent depressurization, including, in some embodiments, evacuation to a lower subatmospheric desorption pressure. By recycling effluent gas released upon copurge and countercurrent depressurization for use in the pressurization or the copurge step, the more readily adsorbable component of the feed gas is advantageously recovered at high purity and at high recovery levels. Enriched less readily adsorbable component is also recoverable as coproduct effluent at relatively high recovery levels. The process can be advantageously employed for the separation and recovery of product nitrogen from air.

Abstract: Normal paraffins present in high concentrations in light naphtha streams are separated from non-normal paraffins in a four or more bed adsorption system employing, on a cyclic basis, the processing steps of (1) cocurrent purge/adsorption, (2) cocurrent feed/adsorption, (3) countercurrent purge and (4) countercurrent displacement. A processing sequence is employed wherein the cocurrent purge/adsorption and countercurrent purge steps are carried out on a discontinuous basis, while cocurrent feed/adsorption and countercurrent displacement steps are carried out in overlapping sequence.

Abstract: In air separation and other gas separations employing pressure swing adsorption technology, reduced cycle times are achieved by an advantageous combination of simultaneous processing steps. The gas released upon cocurrent depressurization from higher adsorption pressure is employed simultaneously for pressure equalization and provide purge purposes. Cocurrent depressurization is also carried out at an intermediate pressure level, while countercurrent depressurization is simultaneously carried out at the opposite end of the bed being depressurized to its lower desorption pressure level.

Abstract: Carbon monoxide-containing gas streams are converted to methane by a cyclic, essentially two-step process in which said carbon monoxide is disproportionated to form carbon dioxide and active surface carbon deposited on the surface of a catalyst, and said carbon is reacted with steam to form product methane and by-product carbon dioxide. The exothermic heat of reaction generated in each step is effectively removed during each complete cycle so as to avoid a build up of heat from cycle-to-cycle, with particularly advantageous techniques being employed for fixed bed, tubular and fluidized bed reactor operations.

Abstract: The in-situ cleaning of conduits containing oily deposits is facilitated by the concurrent passage of cleaning particles and a non-agglomerating drying agent therethrough in a propelling gas stream. In cycling cleaning operations, the preliminary injection of drying agent into the conduit prior to said concurrent use of cleaning particles and drying agent further enhances the overall in-situ cleaning operation.

Abstract: The conversion of synthesis gas to liquid molar fuels by means of a cobalt Fischer-Tropsch catalyst composition is enhanced by the addition of molybdenum, tungsten or a combination thereof as an additional component of said composition. The presence of the additive component increases the olefinic content of the hydrocarbon products produced. The catalyst composition can advantageously include a support component, such as a molecular sieve, co-catalyst/support component or a combination of such support components.

Abstract: A reciprocating-type pump with simplified construction and enhanced performance is achieved by the use of a unitary, rigid pump body support structure and modular pump component designs. This unitary structure includes forward and rearward pump body mounting plates to which the pump body is secured, with the overall support structure being securely attached to the power frame of the pump by means of a power frame mounting plate. Rigid connecting members secure said plates together to form the unitary structure that is particularly advantageous for use in the fabrication of cryogenic pumps suitable for high pressure operation. Valve means, packing means and a pump body cooling jacket can be conveniently secured to the unitary support structure.

Abstract: The reformed gas mixture to be employed for ammonia synthesis is purified, following shift conversion, by the selective catalytic oxidation of residual carbon monoxide and the selective adsorption of carbon dioxide and water so as to render unnecessary the methanation of carbon oxides.

Abstract: An improved process for cleaning the interior of a conduit having a series of straight sections and bends. The process includes passing a transit line having a multiplicity of flow divertors positioned at intervals along the length thereof through said conduit. By injecting a propelling gas stream having cleaning particles entrained therein, the multiplicity of flow divertors serve to enhance the in-situ cleaning action of the particles while the propelling gas stream serves to activate the flow divertors and cause the transit line to move along the straight sections and around the bends of the conduit.

Abstract: Synthesis gas comprising carbon monoxide and hydrogen is converted to C.sub.5.sup.+ hydrocarbons suitable for use as liquid motor fuels by contact with a dual catalyst system capable of enhancing the selectivity of said conversion to motor fuel range hydrocarbons and the quality of the resulting motor fuel product. The catalyst composition employs a Fischer-Tropsch catalyst, together with a co-catalyst/support component comprising SAPO silicoaluminophosphate, non-zeolitic molecular sieve catalyst.

Abstract: Effluent gas streams for steam reforming, partial oxidation or coal gasification operations are advantageously treated in shift conversion, scrubbing and pressure swing adsorption units for recovery of a purified, hydrogen-containing product gas stream. By recycling a portion of the waste gas removed from the pressure swing adsorption system to the shift conversion unit and/or to the effluent gas generation operation, enhanced product recovery is achieved without the necessity for employing low temperature shift or for achieving essentially complete removal of the carbon dioxide content of the gas being treated prior to its passage to said pressure swing adsorption system.

Abstract: A gas-liquid contacting tray for use in a gas-liquid contacting tower is provided with a wall member at the discharge region of the tray wherein the wall member has one or more apertures for discharging a liquid flowing across the surface of the tray thereby providing for stable tray performance over a wide range of turn-down.

Abstract: A pressure swing adsorption process is used to achieve intermediate product recovery by the introduction of a gas displacement step before, simultaneous with or subsequent to pressure equalization between beds of a multi-bed adsorption system. A cocurrent depressurization step is then employed to achieve intermediate product recovery. A portion of said intermediate product or of the more readily adsorbable component recovered from a bed advantageously being employed to provide displacement gas for another bed in the adsorption system.

Abstract: The heat capacity of activated carbon adsorbent pellets is enhanced by the mixing of activated carbon powder with a higher heat capacity, inert inorganic material, such as dense alumina, prior to pelletizing. The resulting doped adsorbent enhances the operation of adiabatic pressure swing adsorption processes by decreasing the cyclic temperature change in the adsorbent bed during each processing cycle of the process.

Abstract: In a process for mixing a gas and a liquid in an apparatus having an axial flow down-pumping impeller located in a draft tube and preceded by a first baffle wherein a vortex and turbulence are created and gas is drawn into the vortex, the improvement comprising providing liquid velocity of at least one foot per second, increasing the turbulence, providing a second baffle below the impeller, and a high shear zone between impeller and the second baffle.