Abstract: Apparatus for dehydrating air to be supplied to a blast furnace comprising a dehydration assembly wherein intake air is dehydrated by contact with a circulating hygroscopic liquid and a regeneration assembly wherein the liquid is regenerated by contact with air under heating with steam, characterized in that a cylinder through which a part of the circulating liquid is caused to flow is provided for comparing the pressure of the liquid with a reference liquid to detect the concentration of the circulating liquid, the regeneration assembly is divided into a plurality of independently operable units each having regeneration means, means for controlling the steam flow rate according to the detected concentration, means for controlling the liquid flow rate according to the detected concentration, and at least one heat exchanger for transferring sensible heat between at least one fluid entering said regeneration means and at least one fluid leaving said regeneration means.

Abstract: Arrangement for preparing dry hot compressed air to be supplied to blast furnace, wherein a heat exchanger and a dehydrater assembly comprising a gas permeable regenerative moisture absorbing rotor are arranged in the air passage from blower to hot air furnaces so that the hot compressed air from the blower may be used to heat the dehydrated air and to regenerate the rotor. Air leakage between regenerating and dehydrating zones in the dehydrater is prevented by sealing those clearances where otherwise such leakage would occur by packing elements to form sealed spaces and externally introducing dry pressurized air into each of said spaces.

Abstract: Assembly for dehydrating atmospheric air at the input side of a blower for supplying air to a blast furnace comprising at least one gas permeable rotor containing a regenerative moisture absorbent wherein a hot combustion gas obtained by burning a waste gas from the blast furnace is utilized for regenerating the absorbent and wherein means for regulating the relative humidity of the moist air to be dehydrated, which does not need any external heat source, is provided to avoid deliquescence of the absorbent. The rotor preferably comprises a layer containing the absorbent and a layer of an adsorbent capable of adsorbing impurities contained in the air.