Abstract: High purity argon is produced by subjecting a two-phase liquid-vapor mixture containing up to 3 volume % of nitrogen and/or up to 5 volume % oxygen to cryogenic temperature swing adsorption in an adsorption bed containing one or more adsorbents selective for nitrogen and/or oxygen at a temperature between the bubble point and the dew point of the two-phase mixture.

Abstract: A mechanism for aligning the elements of an optical system is disclosed. One aspect of the present invention is an alignment mechanism which includes lead screws placed on opposite corners of the elements to be aligned. The elements are provided with threaded holes of different pitch, and the lead screw is provided with threads of the same unequal pitches as the elements, thereby forming a differential lead screw. The threads include a locking thread which assures a positive lock between the lead screw and the elements to be aligned and eliminates backlash between them. Another aspect of the present invention is an interference fit mechanism which is provided by the employment of a slightly-oversized flexible boss which mates with a cavity. The boss is provided with a thin outer wall capable of flexing when the boss is inserted into the cavity. Yet another aspect of the present invention includes a wobble plate comprising a spherical socket and housing.

Abstract: An anesthetic vaporizer is disclosed having an inlet for receiving carrier gas and an outlet for delivering carrier gas with an anesthetic agent to a patient. The vaporizer has a passage that extends between the inlet and the outlet, a vaporizing chamber and a passageway extending from the vaporizing chamber to the outlet. A means such as a differential pressure transducer monitors the differences in pressure between the carrier gas in the passage and the anesthetic agent in the passageway to control the flow of the anesthetic agent through the passageway.

Abstract: An apparatus comprising a liquid-vapor contact column housing an array of vertically spaced liquid-vapor contact trays and an arrangement of downcomers that conduct liquid from tray-to-tray down the array. In a vapor space between the trays there are liquid-vapor disengagement devices having vapor passages therethrough and defining surfaces for the flow thereacross of any liquid disengaged from vapor ascending the column. Each of the devices is typically provided by a sheet of expanded metal and has an outlet edge in liquid flow communication with the next lower tray via the downcomer.

Abstract: An oxygen delignification method and apparatus in which a charge of heated wood pulp is reacted with oxygen in the presence of a charge of caustic soda in a plurality of reaction stages located between mixing stages in which caustic is mixed with the wood pulp. The use of the plurality of mixing stages reduces peak pH exposure of the wood pulp that would otherwise occur if the charges of caustic and wood pulp were mixed all at once. Moreover, the caustic mixed in such manner replenishes neutralized caustic and ensures that the average pH level is increased above that in conventional oxygen delignification. The increase in average pH level favors an increase in the delignification. Filtrate from a washing stage is introduced into the mixing stages to prevent wood pulp degradation.

Abstract: Carbon dioxide is removed from a gas stream by passing the gas stream through a bed of natural or synthetic clinoptilolite or their chemically-modified derivatives. The process is particularly advantageous when applied to the removal of ppm levels of carbon dioxide from gas streams at temperatures above 20.degree. C.

Abstract: A method of producing nitrogen is a single column nitrogen generator in which first and second coolant streams are used to condense nitrogen-rich tower overhead to provide reflux for the distillation column. One of the coolant streams is composed of liquid having a higher nitrogen content than oxygen-rich liquid produced in a bottom region of the distillation column. This coolant stream is compressed, cooled and recycled to the bottom of the distillation column in order to increase nitrogen recovery.

Abstract: Cooled and purified air is introduced into a higher pressure rectification column and separated into oxygen-enriched liquid and nitrogen vapor. A stream of the oxygen-enriched liquid is flashed through a pressure reducing valve to form a mixture of liquid further enriched in oxygen and vapor depleted of oxygen. The liquid is reboiled by reboiler. A stream of the further enriched liquid is reboiled in condenser and is introduced into a lower pressure rectification column for separation into oxygen and nitrogen products. Reflux for the columns and is formed by condensing in condenser nitrogen vapor separated in the higher pressure rectification column. A reboiler provides an upward flow of vapor through the column. The condenser and reboiler take the form of a single heat exchanger. The reboiler is located in a phase separator, the reboiler is located in a rectification column containing liquid-vapor contact devices above the level at which fluid issuing from the valve is introduced.

Abstract: Air is compressed in a compressor, cooled in a main heat exchanger, partially condensed in a reboiler-condenser, introduced into a higher pressure rectifier, and separated therein into nitrogen and oxygen-enriched liquid. Resulting nitrogen is condensed in further reboiler-condensers. One part of the condensate is used as reflux in the higher pressure rectifier and another part as reflux in a lower pressure rectifier. A stream of oxygen-enriched liquid is withdrawn from the high pressure rectifier and sent to an intermediate pressure rectifier which is reboiled by one of the further reboiler-condensers and in which further nitrogen is separated. A stream of liquid further enriched in oxygen is withdrawn from the bottom of the intermediate pressure rectifier and is separated in the lower pressure rectifier and impure and pure oxygen products are withdrawn respectively therefrom.

Abstract: A cryogen delivery apparatus for delivering cryogen in a saturated state includes a vessel to contain the cryogen in liquid and vapor phases. The vessel has a headspace region and a heat exchanger located within the headspace region for indirectly exchanging heat between the vapor located within the headspace region and a liquid stream composed of the liquid phase of the cryogen. In case the cryogen is introduced into the vessel as a subcooled liquid, the vapor will condense into the liquid phase and the subcooled liquid will be converted into a saturated liquid. The saturated liquid will then be discharged from a liquid outlet connected to the heat exchanger. In the event the liquid enters the vessel as two-phase flow, the vessel will act as a phase separator. A branched supply line is provided having a liquid inlet branch connected to a bottom liquid inlet of the vessel so that a supply stream composed of the cryogen flows into the vessel.

Abstract: Cooled and purified air is introduced into a higher pressure rectifier in at least partly vaporous state and is separated therein into oxygen-enriched liquid air and nitrogen. One part of the nitrogen so separated is condensed in a reboiler-condenser and another part in a reboiler-condenser. Some of the condensate is used as reflux in the high pressure rectifier, and the rest of the condensate as reflux in a lower pressure rectifier. Oxygen-enriched liquid air is taken from the bottom of the higher pressure rectifier and is separated into oxygen and nitrogen in the lower pressure rectifier. A liquid argon-enriched oxygen stream is withdrawn from the lower pressure rectifier through an outlet and is separated into argon and oxygen fractions in a further rectifier. The further rectifier is reboiled by the reboiler-condenser.

Abstract: Air is introduced through an inlet into a higher pressure rectification column. A stream of oxygen-enriched liquid is withdrawn through an outlet from the higher pressure rectification column. A part of this stream is introduced into a low pressure rectification column through an inlet. The stream is separated in the column low pressure rectification into oxygen and nitrogen. In addition, an argon-enriched vapor stream is withdrawn from the low pressure rectification column through an outlet, and is at least partially condensed in a reboiler-condenser which reboils oxygen separated in an argon column. One part of the resulting at least partially condensed argon-enriched oxygen stream is reduced in pressure by passage through a valve and is introduced through an inlet into an intermediate mass exchange region of the argon column in which it is separated into argon and oxygen.

Abstract: A rotary vacuum pump having a low vacuum stage and a high vacuum stage. Each stage includes a stator body having a bore and a rotor mounted eccentrically in the bore to form a cavity between the stator body and the rotor. The rotor of each stage has two vanes slidably positioned in diametrically opposed slots in the rotor which in use of the pump are substantially in contact with an inner wall of the stator body during rotation of the rotor. The stator body of each stage has an inlet and an outlet to allow, in use of the pump, fluid being pumped to enter into and be expelled from the cavity by means of the rotating vanes. Oil to be injected into the low vacuum stage and, when required, into the high vacuum stage also. Differential flow rates (including zero) of ballast gas are introduced to the low vacuum stage, for example in an amount in excess of ten percent of the overall vacuum pump capacity (which equates to the capacity of the high vacuum stage).

Abstract: A cryogenic refrigeration method for use in connection with a cryogenic temperature swing adsorption process. The cryogenic temperature swing adsorption process has a discontinuous production cycle during which production of a purified vapor stream ceases or is reduced through use of purified vapor to purge a regenerating adsorption bed. Additionally, the purified vapor stream in part of the production cycle is superheated through use of the purified vapor stream to cool the regenerating adsorption bed. A heat exchange stream is liquefied against the vaporization of at least part of an impure liquid stream to produce an impure vapor stream to be purified by the adsorption process. Process liquid is continually produced from the liquefaction of the process stream. The process liquid is used to in turn liquefy the purified vapor stream at varying flow rates that are sufficient to liquefy the purified vapor stream throughout the production cycle.

Abstract: An apparatus for storing a multi-component cryogenic liquid in which headspace vapor in a storage tank is condensed in an external condensation tank through indirect heat exchange with liquid being vented from the storage tank. The resulting condensate can then be re-introduced into the storage tank through a pressure building circuit applied to the external condensation tank. In such manner, the pressure within the storage tank is regulated and the composition of the liquid stored within the storage tank is held with some degree of consistency. The use of an external condensation tank allows prior art cryogenic storage tanks and dewars to be retrofitted to store a multi-component cryogenic liquids.

Abstract: An adsorption process in which high and low pressure feed streams are introduced into a plurality of beds to produce product streams by adsorbing one or more preferentially adsorbed components within the beds. Each bed is subjected to a low pressure feed stage to produce a low pressure product stream followed by a high or higher pressure feeding stages to produce one or more high pressure product streams. Thereafter the beds are regenerated through depressurization and purge stages. The cycle is conducted out of phase so that one of the beds is producing the high pressure product stream while another bed is producing a low pressure product stream.

Abstract: Coke deposits are removed from particulates by combustion in a regenerator by a process in which air is initially used as the oxidant. The combustion gas is subjected to a separation process to remove nitrogen therefrom, and the remaining carbon dioxide-enriched gas stream is recycled to the regenerator together while substantially pure oxygen is introduced into the regenerator. As the level of carbon dioxide in the system increases, the amount of air being introduced into the regenerator is gradually reduced and, in compensation, the amount of oxygen flowing to the regenerator is gradually increased. Eventually, part or all of the air is replaced by oxygen and carbon dioxide recycle gas, and the level of oxygen and carbon dioxide are regulated to maintain the desired temperature in the regenerator.

Abstract: This apparatus makes use of the existing data collection probe connector on the instrumentation as the port through which the software updates are loaded into the programmable memory devices that are used to store the operational software of the instrumentation. Circuitry is provided in the instrumentation to automatically differentiate between software update data being loaded into the instrumentation and the normal monitoring data that is received from the probe. This is accomplished by the use of probe defining circuitry that is able to differentiate between the standard probe used for data collection purposes and the software update probe that is provided to download software into the programmable memory devices.

Abstract: Hydrocarbon fluid catalytic cracking (FCC) plants are debottlenecked by replacing air feed to the cracking catalyst regenerator with oxygen and carbon dioxide exhaust from the catalyst regenerator and removing methane and hydrogen from the wet gas stream leaving the main fractionator overhead receiver prior to its introduction into a wet gas compressor system. Nitrogen is removed from the exhaust gas and methane and hydrogen are removed from the wet gas in the same pressure swing adsorption (PSA) plant. During air replacement, exhaust gas is processed in the PSA plant and when the desired amount of nitrogen is removed from the exhaust gas, feed of exhaust gas to the PSA plant is terminated and flow of wet gas to the PSA plant is initiated.

Abstract: An air separation method in which a pre-purification unit is provided with three or more beds which are subjected to a pressure swing adsorption process. Each of the beds is subjected to feed, pressurization, purge and repressurization stages. The purge stages are conducted with a waste stream from the air separation unit and the duration of the purge stage is equal to the total time of the cycle divided by the number of beds.