(JP7014597-A)      Air is filtered (2) and fed to a compressor inlet (6). After compression the air is mixed (10) with injected (8) water and is fed to the moisture unit (14) of the fuel cell (12). The mix of saturated air and water is fed to an expander stage (18) via a liquid extractor (18) and is recirculated through the compressor. The process is regulated by varying the speed of the compressor motor based upon measured parameters, such as fixed cell current and flow rate. The compressor is of a positive displacement type, with sealed clearance, oil free operation and providing a speed range of 1:10.    USE/ADVANTAGE -   Reduced complexity and reduced auxiliary power requirement.    (JP7014599-A)      Air is filtered (2) and fed to a compressor inlet (6). After compression the air is mixed (10) with injected (8) water and is fed to the moisture unit (14) of the fuel cell (12). The mix of saturated air and water is fed to an expander stage (18) via a liquid extractor (18) and is recirculated through the compressor. The process is regulated by varying the speed of the compressor motor based upon measured parameters, such as fixed cell current and flow rate. The compressor is of a positive displacement type, with sealed clearance, oil free operation and providing a speed range of 1:10.    USE/ADVANTAGE -   Reduced complexity and reduced auxiliary power requirement.    (DE4318818-C2)      The arrangement is provided for the preparation of air for use in air breathing fuel cells. The air is draw in from the atmosphere (4) through a filter (2) and is received by a compressor (6). It is then mixed (10) with injected water vapour from an injector pump (8) before being supplied to the fuel cell.    The mixture of moist air and water droplets are passed through an expander stage (16) that connects with a liquid separator (18). The compressor is driven by a motor (30) and a separate motor (28) is used for starting.    USE/ADVANTAGE -   Fuel cell has increased efficiency and power density.    (US5432020-A)      The process involves using an appts. having a supply line (2) for supplying process gas to an air-breathing fuel cell (1). An air supported injection nozzle (5) which injects a metered quantity of finely atomized water is also included and is arranged in the supply line before the process gas enters the fuel cell. The atomised water is mixed in a chamber (4) before entering the cell.    A metered quantity of finely atomized water is injected into the process gas before the process gas enters into the supply line for supplying the fuel cell. The metered quantity of injected water is determined by a controller (9) as a function of operating conditions. The injected water has droplets with a diameter smaller than a diameter of gas-conducting channels in the fuel cell.    ADVANTAGE -   Requires less space for humidifying process gasses. Amount of water can be adjusted rapidly to dynamic load changes.    (US5434016-A)      The treatment apparatus (1) includes an air supply line (3) associated with a fuel cell (12) and a variable-speed compressor (6) located in the air supply line. An air discharge line via gear box case (26) is associated with the fuel cell and a variable absorption capacity expander (16) is located in the air discharge line.    A common shaft (20) holds the compressor and the expander and a controller (11) sets predetermined values of compressor rotary speed and the expander absorption capacity. An air register (32) is arranged upstream of the expander to suck in ambient air at the predetermined pressure. A continuously excited synchronous electric motor (30) and a starter motor (28) are arranged on the common shaft and are supplied with the fuel cell system voltage and with a starter battery voltage respectively.    USE/ADVANTAGE -   Pref. for fuel cells with proton conducting electrolyte membranes, mobile fuel systems, e.g. trains, automobiles, as decentralized power system.    (EP629013-B2)      Air is filtered (2) and fed to a compressor inlet (6). After compression the air is mixed (10) with injected (8) water and is fed to the moisture unit (14) of the fuel cell (12). The mix of saturated air and water is fed to an expander stage (18) via a liquid extractor (18) and is recirculated through the compressor. The process is regulated by varying the speed of the compressor motor based upon measured parameters, such as fixed cell current and flow rate. The compressor is of a positive displacement type, with sealed clearance, oil free operation and providing a speed range of 1:10.    USE/ADVANTAGE -   Reduced complexity and reduced auxiliary power requirement.    (DE9422387-U1)      Air is filtered (2) and fed to a compressor inlet (6). After compression the air is mixed (10) with injected (8) water and is fed to the moisture unit (14) of the fuel cell (12). The mix of saturated air and water is fed to an expander stage (18) via a liquid extractor (18) and is recirculated through the compressor. The process is regulated by varying the speed of the compressor motor based upon measured parameters, such as fixed cell current and flow rate. The compressor is of a positive displacement type, with sealed clearance, oil free operation and providing a speed range of 1:10.    USE/ADVANTAGE -   Reduced complexity and reduced auxiliary power requirement.