Abstract: A method of making thin-walled permeable tubing using air blown extrusion, and of using the tubing in a device which enables a substantial humidification or drying of patient breathing gases in the breathing lines for patient monitoring or anesthesia results in cost savings and increased efficiency.

Abstract: A method of making thin-walled permeable tubing using air blown extrusion, and of using the tubing in a device which enables a substantial humidification or drying of patient breathing gases in the breathing lines for patient monitoring or anesthesia results in cost savings and increased efficiency.

Abstract: In humidifying the fuel input to a fuel cell, a stream of dry inlet gas is passed inside the strands of liquid permeable tubes. A stream of hot wet exhaust gas from the fuel cell or hot cooling water from the fuel cell is passed over the outside of the tubing bundle in a counter-current flow direction. Water vapor from the hot wet exhaust gas or liquid water from the hot cooling water is absorbed onto the outside surface of the permeable tubing, permeates through the walls of the tubing, and pervaporates into the dry gas stream inside the tubing. At the same time, heat from the exhaust gas or cooling water is conducted through the tubing walls into the dry gas stream inside. The permeation of water also carries heat with it, increasing the efficiency of heat recovery and transfer into the inlet fuel/oxidant gas.