Abstract: Process and apparatus for reducing the liquid content of a porous material by means of superheated vapor from said liquid. The apparatus comprises, in order: a vapor generator 1; a circulation fan 2; a vapor superheater 6; a closed, sealed chamber 7, and an assembley 22-26 to provide in the chamber 7 a passage for fluid and for supporting textile material 9 such that it is interposed in the path of the vapor; a vapor condenser 13; a valve for regulation of pressure 16; a conduit for recycling vapor 17, and a device 32, 32a to measure the temperature prevailing in the fluid passage upstream of the porous material.

Abstract: A psychrometer or pick-up for measuring the content of water in a gas flow comprises a first sensor or probe for measuring the dry temperature of the gas and is arranged directly in the flow of gas, a second sensor or probe for measuring the wet temperature of the gas and is surrounded by a sheath of a material capable of absorbing a volatile liquid, the second sensor or probe with its sheath also being arranged in the flow of gas, a pair of screens mounted on opposite sides of the second sensor and the sheath for protecting the sheath against thermal radiation, and a wetting device, preferably formed by a dosing pump connected to a nozzle, for injecting successive doses of a predetermined amount of the volatile liquid directly into the interior of the sheath and onto the screens to prevent excessive and insufficient moistening of the sheath and the screens.