Pressure-heat drying method and an apparatus therefor

The present invention relates to a pressure-heat drying method for controlling a drying process such that catalyst and the like may be uniformly deposited onto a workpiece made of porous material, such as ceramics, or metallic material, and also to an apparatus therefor. An object of the present invention is to provide a pressure-heat drying method which allows a catalytic substance and the like to be deposited uniformly onto a workpiece to be dried in a dramatically short time as compared to a prior art method, and also an apparatus therefor. The present invention provides a pressure-heat drying method for drying a workpiece to be dried in a pressure vessel, said workpiece coated with a solution containing a solute dissolved in a solvent adhering thereto, said method comprising: a pressure increase process for increasing a pressure in said pressure vessel to a set pressure higher than a saturated vapor pressure of said solvent at a set temperature; a temperature increase process for increasing a temperature in said pressure vessel to said set temperature under a condition where an evaporation of said solvent is suppressed with the aid of said set pressure which has been achieved through said pressure increase process; a pressure and temperature maintenance process for maintaining said set pressure and said set temperature in said pressure vessel at constant levels, respectively; and a pressure reduction and deposition process for reducing said set pressure to a level lower than the saturated vapor pressure at said set temperature and thereby stimulating a rapid evaporation of said solvent so as to allow said solute to be uniformly deposited onto said workpiece.