Praxair Technology, Inc.

Michael S Manning

Andrew Chester Rosinski

Paul William Belanger

James Smolarek

Mohamed Safdar Allie Baksh

Ahmed F Abdelwahab

Bernard Thomas Neu

Garrett R Swindlehurst

Alan Barnard Stewart

Ashwin Desai

Preeti Chandra

Murali Chinta

Gerald Thomas O'Connor

Robert B Bollinger

Ahmed Abdelwahab

The present invention relates to a method and control system to control the speed of centrifugal compressors 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, while subsequently operating the vacuum pressure swing process between set limits of highest adsorption and lowest desorption pressure. 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. The speed is then adjusted by a global speed factor which serves to adjust the average speed of the motors over all steps of the repeating cycle such that the process operates within high and low pressure limits.

Anti-surge speed control for two or more compressors

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.

Anti-surge speed control

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.

Cyclic adsorption process using centrifugal compressors

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.

Cyclic adsorption process using centrifugal machines

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.

Systems and processes are provided for gas separation using high-speed induction variable-speed motors to accelerate and decelerate centrifugal compressors suitable for use in pressure swing adsorption (PSA) or vacuum pressure swing adsorption (VPSA) processes.

Systems and methods for gas separation using high-speed induction motors with centrifugal compressors

The present invention relates to a dual feed and dual vacuum four bed VPSA process for selectively adsorbing a component from a feed stream, e.g., nitrogen from air, to produce an oxygen-enriched gas stream using a multi-port indexing drum valve, a system comprising a multi-port indexing drum valve and method for operating such a system.

Multi-port indexing drum valve for VPSA

Systems and processes are provided for gas separation using high-speed permanent magnet variable-speed motors to accelerate and decelerate centrifugal compressors suitable for use in pressure swing adsorption (PSA) or vacuum pressure swing adsorption (VPSA) processes.

Systems and methods for gas separation using high-speed permanent magnet motors with centrifugal compressors

The present invention relates to a PSA system using an indexing rotary dual valve regulating a stepping mode of operation that controls a variable bed inlet feed flow rate, controllable pressure between feed lines in different beds of the PSA system and varied output flow rate of product gas such as high purity hydrogen gas.

Indexing rotary dual valve for pressure swing adsorption systems

A method and apparatus for introducing a compressed gas into a pressure vessel, for instance, hydrogen into a vehicle fuel tank, in which hydrogen is compressed in an initial and final compressions stages which can be powered by a common source. The initial compression stage can continually operate to compress the gas in a lower pressure storage bank during the time that hydrogen is dispensed to a vehicle fuel tank. In time periods between dispensing, the gas from the lower pressure stage and from the lower pressure storage bank is compressed in the final compression stage and stored in a higher pressure storage bank. When the pressure vessel is to be filled, the compressor compresses the gas from the higher pressure storage bank to fill the vessel.

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Buffalo, NY, United States of America

Michael S Manning