Abstract: Lithium/alkaline earth metal X zeolites in which the lithium:alkaline earth metal equivalent ratio is from about 95:5 to about 50:50 and lithium/alkaline earth metal A zeolites in which the lithium:alkaline earth metal equivalent ratio is from about 10:90 to about 70:30 are useful for separating oxygen and nitrogen from mixtures because they combine high adsorption capacity with high thermal stability.

Abstract: The pump energy requirements for the dissolving of a gas in a liquid are significantly reduced by injecting gas bubbles into a stream of said liquid at a relatively low pressure, utilizing a pressure head of liquid to increase the solubility of the gas in the liquid, and employing liquid stream velocities and gas-liquid contractor diameters and lengths, gas dispersion means and residence times such as to obtain a desired level of gas concentration in the liquid.

Abstract: A refractory sheet member is positioned in a cut-out portion of graphite side and end plates of an aluminum holding and refining vessel to create an effective barrier to the flow of molten aluminum through the channel formed upon the pulling of the plates apart when the vessel is heated to operating temperature.

Abstract: The present invention provides a method and apparatus for controlling the fluid flow bias of continuous, multiple zone processes having gas or vapor comprising atmospheres that are in immediate access to each other. Active control of the fluid flow bias in at least one process zone or control of the overall process fluid flow bias is achieved by applying force to at least one of the zones of the process in a manner which enables such control. A physical or chemical property or a change thereof in at least one process atmosphere is monitored and an appropriate amount of force is applied in response to the monitored property. The monitored property is related to the furnace flow bias by an algorithm, so that the flow bias can be controlled by controlling the at least one chemical or physical property monitored.

Abstract: Composite membranes are disclosed having a separation layer comprised of a mixture of poly(methy methacrylate) or a copolymer thereof and at least one cellulosic derivative resulting in enhanced separation and permeating characteristics of the overall composite membrane. Processes for making these composite membranes and the methods of using them are also disclosed. The membranes are particularly useful in gas separation applications and are most suited for the separation of hydrogen from a hydrogen containing stream.

Abstract: Gas dispersion in a liquid is enhanced by combining the gas and liquid in close proximity to a venturi or other flow constriction means used to create supersonic flow velocities and subsequent deacceleration to sub-sonic velocity. When a venturi is employed, the gas-liquid mixing occurs in the converging portion of the venturi or upstream but in close proximity to said venturi. Turbulent flow conditions upstream of the venturi or other flow constriction means adequate to disperse the gas uniformly in the liquid are not required and, surprisingly, the gas and liquid need not be uniformly dispersed prior to acceleration to supersonic velocity.

Abstract: A support plate is used, together with the shell of a vessel for the holding and/or refining of aluminum, in combination with a refractory sheet and a metal heating element container positioned in a graphite block to protect said heating element and to thus extend the life of said heating element. Oxidation of the graphite block is precluded, as is the attack upon the heating element by chlorides passing through the pores of said graphite block.

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: 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: 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: 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 method for forming a porous aluminum surface on an aluminum substrate using a potassium fluoaluminate brazing flux in critical weight ratio of 0.05 to 0.6 with an aluminum powder matrix component.

Abstract: A gas-liquid contacting tray of the crossflow type with improved means for initiating bubbling activity at the tray inlet region comprising spaced-apart imperforate wall members extending substantially vertically upwardly and transverse to the liquid flow path, contiguously associated and coextensive at their upper edges with an intermediate perforated wall member horizontally extending therebetween.

Abstract: A synthesis gas stream having a H.sub.2 /CO ratio of less than 3/1 is split, with one stream being subjected to water gas shift essentially to completion, adjusted with a portion of the other stream to a carbon monoxide content of about 3-6% by volume, and reacted in an adiabatic methanation zone. The high hydrogen composition and high H.sub.2 /CO ratio of the stream passed to the adiabatic zone is effectively regulated in this manner, preventing carbon formation and catalyst sintering. The effluent from said adiabatic zone is mixed with the remaining portion of the other stream and passed to an isothermal methanation zone. Carbon dioxide can be removed from the product methane-rich gas or from the methanation feed gas. In preferred embodiment, high pressure superheated steam is simultaneously produced by utilization of the heat of reaction of the methanation operations, enhancing the overall efficiency of the synthesis gas production-methanation operation.

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.