Abstract: A device for treating a fuel/coolant mixture in a fuel cell system. The fuel cell system is in particular a direct methanol fuel cell system. The fuel cell system is in particular a direct methanol fuel cell system. The fuel/coolant mixture circulates in a circuit system which has a mixture-conveying device, an anode chamber of a fuel cell and an ion exchanger. Furthermore, fuel is guided out of a tank into the circuit system via a line. In addition, a cation exchanger is arranged in the circuit system.

Abstract: A device for treating a fuel/coolant mixture in a fuel cell system. The fuel cell system is in particular a direct methanol fuel cell system. The fuel cell system is in particular a direct methanol fuel cell system. The fuel/coolant mixture circulates in a circuit system which has a mixture-conveying device, an anode chamber of a fuel cell and an ion exchanger. Furthermore, fuel is guided out of a tank into the circuit system via a line. In addition, a cation exchanger is arranged in the circuit system.

Abstract: In method for soldering metal microstructured plates, stacks of plates and solder layers are prepared by placing the solder layers between each adjacent plate. The thickness of the solder layers range from 3 to 25 &mgr;m. The stack is then soldered by heating it in a vacuum or an inert atmosphere.

Abstract: A two-stage evaporator unit converts a liquid reactant mass flow adjustable as a function of a load presetting into a gaseous reactant mass flow. The liquid reactant mass flow is at least partially evaporated in the first stage by a heat-exchange medium, and, if appropriate is completely evaporated and subsequently superheated in the second stage. The evaporator unit is formed by the alternating stacking one on the other of foils having heat-exchange channels and by foils having reaction channels that, in each case, have at least one first and one second stage integrated in one foil. The first stage is configured as a channel with a minimized cross-sectional area which is directly connected to the inflow conduit. The first stage is operated at high coefficients of heat transmission. The total cross-section of the reaction channels in the second stage increases in the flow direction.