Abstract: Closed-loop refrigeration cycles for liquid oxygen densification are disclosed. The disclosed refrigeration cycles may be turbine-based refrigeration cycles or a Joule-Thompson (JT) expansion valve based refrigeration cycles and include a refrigerant or working fluid comprising a mixture of neon or helium together with nitrogen and/or oxygen.

Abstract: The invention relates to a method and control system to control the speed of a centrifugal compressor operating within a vacuum pressure swing adsorption process to avoid an operation at which surge can occur and directly driven by an electric motor that is in turn controlled by a variable frequency drive. The claimed method determines the optimal speed for operation of the compressor along a peak efficiency operating line of a compressor map thereof. Speed of the compressor is adjusted by a feed back speed multiplier when the flow or other parameter referable to flow through the compressor is below a minimum and a feed forward multiplier during evacuation and evacuation with purge steps that multiplies the feed back multiplier to increase speed of the compressor and thereby avoid surge.

Abstract: A cyclic adsorption process is provided, the process containing one or more adsorber vessels undergoing the steps of at least pressurization and depressurization and driven by one or more variable speed centrifugal machines operating under acceleration and deceleration conditions and adjusted to the steps, vessel size, and process conditions employed, wherein the process cycle time is greater than the ratio of the change in inertia, defined the maximum energy that can be lost during a cycle due to inertia changes, to 0.3 times the total power of the one of more centrifugal machines that would be consumed in the absence of inertial effects.

Abstract: A cyclic adsorption process is provided having pressurization and depressurization steps and driven by one or more centrifugal machines operating under acceleration and deceleration conditions wherein the deceleration rate of the machine is controlled to minimize power consumption and maximize the efficiency of the process. The operating speed of the centrifugal machine during deceleration is matched to the measured pressure ratio conditions so that the centrifugal machine arrives at its minimum operating speed near the point required to begin acceleration.

Abstract: A cyclic adsorption process is provided having pressurization and depressurization steps and driven by one or more centrifugal machines operating under acceleration and deceleration conditions wherein the deceleration rate of the machine is controlled to minimize power consumption and maximize the efficiency of the process. The operating speed of the centrifugal machine during deceleration is matched to the measured pressure ratio conditions so that the centrifugal machine arrives at its minimum operating speed near the point required to begin acceleration.

Abstract: A cyclic adsorption process is provided having pressurization and depressurization steps and driven by one or more centrifugal machines operating under acceleration and deceleration conditions wherein the deceleration rate of the machine is controlled to minimize power consumption and maximize the efficiency of the process. The operating speed of the centrifugal machine during deceleration is matched to the measured ratio pressure conditions so that the centrifugal machine arrives at its minimum operating speed near the point required to begin acceleration.

Abstract: A cyclic adsorption process is provided, the process containing one or more adsorber vessels undergoing the steps of at least pressurization and depressurization and driven by one or more variable speed centrifugal machines operating under acceleration and deceleration conditions and adjusted to the steps, vessel size, and process conditions employed, wherein the process cycle time is greater than the ratio of the change in inertia, defined the maximum energy that can be lost during a cycle due to inertia changes, to 0.3 times the total power of the one of more centrifugal machines that would be consumed in the absence of inertial effects.

Abstract: A cyclic adsorption process is provided, the process containing one or more adsorber vessels undergoing the steps of at least pressurization and depressurization and driven by one or more variable speed centrifugal machines operating under acceleration and deceleration conditions and adjusted to the steps, vessel size, and process conditions employed, wherein the process cycle time is greater than the ratio of the change in inertia, defined the maximum energy that can be lost during a cycle due to inertia changes, to 0.3 times the total power of the one of more centrifugal machines that would be consumed in the absence of inertial effects.

Abstract: The present invention relates to a method and control system to control the speed of a centrifugal compressor operating within a vacuum pressure swing adsorption process to avoid an operation at which surge can occur and directly driven by an electric motor that is in turn controlled by a variable frequency drive. In accordance with present invention an optimal speed for operation of the compressor is determined at which the compressor will operate along a peak efficiency operating line of a compressor map thereof. This speed is adjusted by a feed back speed multiplier when the flow or other parameter referable to flow through the compressor is below a minimum and a feed forward multiplier during evacuation and evacuation with purge steps that multiplies the feed back multiplier to increase speed of the compressor and thereby avoid surge.

Abstract: The present invention relates to a method and control system to control the speed of a centrifugal compressor operating within a vacuum pressure swing adsorption process to avoid an operation at which surge can occur and directly driven by an electric motor that is in turn controlled by a variable frequency drive. In accordance with present invention an optimal speed for operation of the compressor is determined at which the compressor will operate along a peak efficiency operating line of a compressor map thereof. This speed is adjusted by a feed back speed multiplier when the flow or other parameter referable to flow through the compressor is below a minimum and a feed forward multiplier during evacuation and evacuation with purge steps that multiplies the feed back multiplier to increase speed of the compressor and thereby avoid surge.

Abstract: A method and apparatus for micro-aeration of large scale fermentation systems is provided. The micro-aeration system includes a fermentation reactor, a sparging apparatus, and a micro-aeration gas mixture delivered to the fermentation reactor via the sparging apparatus. The micro-aeration gas mixture is a very low oxygen concentration mixture comprising an oxygen containing gas and an inert carrier gas that is preferably recycled through the fermentation reactor. The inert carrier gas is preferably nitrogen whereas the oxygen containing gas is oxygen or and is introduced to the fermentation reactor at a minimum superficial velocity of about 0.02 m/sec to produce a uniform dispersion of the oxygen/air throughout the fermentation broth while concurrently mixing the entire fermentation broth. The micro-aeration method and apparatus further comprises a controller operatively coupled to one or more control valves for regulating the micro-aeration conditions in the fermentation reactor.

Abstract: A cyclic adsorption process is provided, the process containing one or more adsorber vessels undergoing the steps of at least pressurization and depressurization and driven by one or more variable speed centrifugal machines operating under acceleration and deceleration conditions and adjusted to the steps, vessel size, and process conditions employed, wherein the process cycle time is greater than the ratio of the change in inertia, defined the maximum energy that can be lost during a cycle due to inertia changes, to 0.3 times the total power of the one of more centrifugal machines that would be consumed in the absence of inertial effects.

Abstract: A cyclic adsorption process is provided having pressurization and depressurization steps and driven by one or more centrifugal machines operating under acceleration and deceleration conditions wherein the deceleration rate of the machine is controlled to minimize power consumption and maximize the efficiency of the process. The operating speed of the centrifugal machine during deceleration is matched to the measured ratio pressure conditions so that the centrifugal machine arrives at its minimum operating speed near the point required to begin acceleration.

Abstract: A cyclic adsorption process is provided, the process containing one or more adsorber vessels undergoing the steps of at least pressurization and depressurization and driven by one or more variable speed centrifugal machines operating under acceleration and deceleration conditions and adjusted to the steps, vessel size, and process conditions employed, wherein the process cycle time is greater than the ratio of the change in inertia, defined the maximum energy that can be lost during a cycle due to inertia changes, to 0.3 times the total power of the one of more centrifugal machines that would be consumed in the absence of inertial effects.

Abstract: The present invention provides a method and a control system for controlling an adsorbent bed unit in which an adsorbent bed concentration of an impurity within an adsorbent bed of the adsorbent bed unit is measured. The adsorbent bed concentration is controlled by manipulating the feed cycle time during which an adsorbent bed is adsorbing the impurities to maintain the adsorbent bed concentration at a targeted adsorption bed concentration. The targeted adsorption bed concentration is determined such that the product impurity concentration is maintained at product impurity concentration targets. The method and control system can incorporate a supervisory level of control reactive to product impurity concentration levels and related targets to determine the targeted adsorption bed concentration and a primary level of control that calculates the feed cycle time based upon an error between the measured and targeted adsorption bed concentrations. Proportional integral control can be used for such purposes.

Abstract: The present invention provides a method and a control system for controlling an adsorbent bed unit in which an adsorbent bed concentration of an impurity within an adsorbent bed of the adsorbent bed unit is measured. The adsorbent bed concentration is controlled by manipulating the feed cycle time during which an adsorbent bed is adsorbing the impurities to maintain the adsorbent bed concentration at a targeted adsorption bed concentration. The targeted adsorption bed concentration is determined such that the product impurity concentration is maintained at product impurity concentration targets. The method and control system can incorporate a supervisory level of control reactive to product impurity concentration levels and related targets to determine the targeted adsorption bed concentration and a primary level of control that calculates the feed cycle time based upon an error between the measured and targeted adsorption bed concentrations. Proportional integral control can be used for such purposes.

Abstract: Methods and apparatus for supplying respiratory oxygen to a patient where the oxygen flow is monitored so as to be control and conserve in response to the patient's pulse rate and blood hemoglobin saturation.

Abstract: Method and apparatus for supplying respiratory oxygen to a patient where the oxygen flow is monitored so as to control and conserve oxygen in response to the pressure in the nasal passages of the patient.