Abstract: A counter flow heat exchanger comprising a central low pressure return tube deformed intermediate its ends to enhance heat transfer capability wrapped by a high pressure tube to conduct fluid to an expansion device. Also disclosed are a method of increasing the heat transfer capacity of a tube bundle heat exchanger and a liquid helium temperature refrigerator or a reliquefier utilizing the heat exchanger.

Abstract: The present invention is an improved ambient-air liquid cryogen vaporizer and a method of using the same. The interconnections between the vertical starfinned pipe lengths of the vaporizer are arranged such that the coldest temperature pipe lengths are placed at more remote locations from the warmer pipe lengths than in previous vaporizer set-ups. This arrangement increases the capacity of the vaporizer by reducing ice bridging between the colder and warmer fins.

Abstract: A chemical absorbent air separation process is set forth which uses a temperature swing absorption-desorption cycle in combination with a pressure swing wherein the pressure is elevated in the desorption stage of the process.

Abstract: A low BTU, low volatile content, low carbon and high ash fuel is combusted in a combined shaft kiln combustor and fluidized bed combustor to generate heat which is converted to useful energy. The fluidized bed combustor is mounted vertically above the shaft kiln combustor. A venturi is provided in a passageway connecting the shaft kiln combustor and the fluidized bed combustor to produce a gaseous stream moving at a velocity sufficient to separate finer particles from the low BTU, low volatile content, low carbon and high ash fuel so that the coarser particles are burned in the shaft kiln combustor and the finer particles are burned in the fluidized bed combustor.

Abstract: The present invention involves a process for removing nitrogen oxides from an off gas stream, such as nitric acid plant tail gas. The off gas is scrubbed with concentrated nitric acid to remove nitrogen oxides to a concentration below about 200 ppm. The nitric acid used in the scrubbing step is subsequently stripped of recovered nitrogen oxides which can be recycled back to a nitric acid plant. The oxidized nitric acid is recovered as concentrated nitric acid which can be used in the initial scrubbing step and/or recovered as product.

Abstract: This invention pertains to the production of aminoethylethanolamine in high selectivity by the intermolecular condensation of monoethanolamine with itself. Selective intermolecular condensation is achieved by reacting monoethanolamine with itself at a temperature from 175.degree.-275.degree. C., and a pressure from 50-400 psig, said reaction being carried out in the presence of a rare earth metal or a strontium metal hydrogen phosphate.

Abstract: A pump for compressing a low temperature high density liquid gas, e.g. liquid helium, wherein the piston is driven by a motor through a four bar linkage which converts rotary motion to reciprocating motion. The pump also includes an improved piston ring assembly, piston venting apparatus and a cushioned discharge valve. A two-stage pump in combination with support equipment provides an improved pumping cycle wherein low temperature density liquid or gas e.g. liquid helium can be withdrawn from a storage reservoir, vaporized and compressed into cylinders.

Abstract: This invention relates to an improvement in a process for producing isobutylene by the cyclic, adiabatic dehydrogenation of isobutane. The improvement resides in diluting an isobutane feed stream with n-butane in an amount from about 3-7% by volume and recycling unreacted products plus nC.sub.4 unsaturates from the dehydrogenation zone. Additional coke is made by virtue of the use of n-butane and recycle to permit lower feed input temperature.

Abstract: Metal corrosion by aqueous acid solutions is inhibited by admixture therein of a synergistic additive consisting essentially of:(1) a heterocyclic nitrogen compound or alkylamine,(2) an acetylenic alcohol, and(3) a dialkylthiourea.In certain instances good inhibition against metal corrosion is obtained without the inclusion of the dialkylthiourea in the additive composition.

Abstract: This invention relates to a process for producing a high purity butene-1 product from n-butane via a dehydrogenation process. In one embodiment of the process the n-butane is dehydrogenated over a chromia-alumina catalyst and any butadiene formed hydrogenated to monoolefins. The monoolefins are separated and the butene-1 separated from isobutylene by reacting the isobutylene with methanol to form methyl tertiary butyl ether. The methyl tertiary butyl ether is separated from the butene-1 leaving it as a high purity product. Alternatively, the dehydrogenated product from the reactor may be contacted with a solvent to extract butadiene followed by hydrogenation, separation of monoolefins and conversion to methyl tertiary butyl ether.

Abstract: In the catalytic reaction of ammonia or formamide with CO and H.sub.2, exceptionally high yields of mono- and di-methyl formamide are obtained among the reaction products when the reaction is carried out in the presence of a platinum group catalyst soluble in the reaction medium, particularly a compound or complex of ruthenium or rhodium, employing a relatively non-volatile polar solvent which does not contain an active methyl function and which does not enter into the reaction producing formamide compounds. The pressure employed is in the range of 3000-8000 psi with a hydrogen partial pressure of at least 1500 psi, the preferred solvent being sulfolane.

Abstract: The present invention involves an improved adsorbent for gas separation processes. The adsorbent comprises a binary ion exchanged Type X zeolite wherein between 5% and 40% of the available ion sites are occupied by Ca, and between 60% and 95% of the available ion sites are occupied by Sr. The present adsorbent is especially useful for the adsorption of N.sub.2 from an air stream at superambient pressure to produce an O.sub.2 -rich product stream.

Abstract: A process is set forth for the selective removal of acid gases such as H.sub.2 S, COS and CO.sub.2 from a gas stream by contacting the stream with a bis tertiary amino alkyl solvent compound such as 4,4'-(oxydi-2,1-ethanediyl) bismorpholine. When used in an aqueous solution, the compounds catalytically hydrolyze COS to H.sub.2 S and CO.sub.2.

Abstract: A method of interference-fitting either a male or female resilient member to its corresponding female or male member using a hollow mandrel cooled to preferably cryogenic temperatures which freezes a compressed resilient member to at least its glass-transition temperature. The method enables one to combine the two members before the resilient member warms to a temperature above its glass-transition temperature. The method and apparatus have found usefulness in the assembly of elastomeric high voltage electrical insulators.

Abstract: This invention pertains to a liquid-gas contacting tray or plate of the sieve type. A plurality of segment zones are established on the tray each having approximately the same area and flow path length. Vertically extending baffles are established within the segment zones to define smaller stages, the baffles being arcuate in shape and of constant radius. A plurality of perforations appear in the floor of the segment zones for vapor passage. By virtue of the establishment of small segment stages of similar length and width, the liquid flow paths, gradients, etc. remain equal and inefficiencies due to local variations in liquid to vapor ratio are minimized.

Abstract: The problem of rising sludge in biological wastewater treatment secondary clarifiers is overcome by minimizing entrainment of nitrogen gas with mixed liquor entering the transfer pipe to the clarifier such that the level of dissolved nitrogen in the biomass settling in the clarifier remains less than that in equilibrium with nitrogen gas at the pressure prevailing in the biomass. This invention is most efficacious in cases where soluble oxides of nitrogen are present and are reduced by the biomass to elemental nitrogen. In accordance with one described embodiment the excess nitrogen is removed by degassing of the mixed liquor in the effluent pit of the system by deepening and widening the usual pit in such manner that the rate of descent of mixed liquor therein to a discharge outlet is less than 0.4 feet per second and the depth is greater than 4 feet, thus permitting the gas-containing macrobubbles to rise to the surface of the pit where these are degassed.

Abstract: The present invention is directed to an extractive distillation separatory technique wherein the improvement comprises a two stage column with a condenser only for the high pressure section and a reboiler only for the low pressure section, as well as a flash separation of a stream communicating between the sections.

Abstract: The removal of paint from a support device for a product in a paint finishing operation is improved by using a support device with a critical surface tension such that paint adheres to the surface, yet readily fractures and debonds when treated with a cryogenic liquid. The paint is then removed by contacting the cryogenically treated support device with a non-metallic, non-silica base solid, gas or liquid with sufficient force to effectively remove the paint.

Abstract: The present invention provides for an improved method of operating an activated sludge system whereby a significant amount of ammoniacal nitrogen is removed in the BOD sorption zone, which does not later appear in the system as protein or NOX. The improved method for achieving said ammoniacal nitrogen removal comprises decreasing the ammoniacal nitrogen concentration of the mixed liquor in the oxidation zone to a point where the mixed liquor leaving the oxidation zone has an ammoniacal nitrogen concentration less than about 0.3 ppm. Additionally, an overall F/M.sub.o ratio equal to or greater than about 0.05 is maintained.

Abstract: A process and system are set forth for improving an oxygen-enriched Claus plant by recycling effluent from the first condenser back to the reaction furnace to moderate oxygen induced high temperatures and thus allow additional oxygen-enrichment and attendant throughput in the Claus plant.