HEAT AND MOISTURE TRANSFER IN TEXTILE ASSEMBLIES .1. STEAMING OF WOOL, COTTON, NYLON, AND POLYESTER FABRIC BEDS

We have studied heat and mass transfer in wool, cotton, nylon, and polyester fabric beds during steaming. Our mathematical model, which is based on local volume average methods, considers the finite rates of heat and mass transfer between the solid, gaseous, and liquid phases of the system. Experiments involve the steaming of fabric beds of various types. Theoretical calculations and experimental work focus on the initial stage of steam penetration characterized by steep rises in bed temperature and moisture content. The effects of fiber diameter, absorption rate, bed porosity, and initial regain on the heat transfer front are examined. With a dry bed of wool or cotton fabric, steaming produces a sharp increase in regain at the heat transfer front, accompanied by a significant rise in the bed temperature. With a nylon or polyester fabric bed, the heat transfer front is followed by a ''transient equilibrium'' period during which the bed temperature remains unchanged.