JPS6488090A - Dust-free thermostatic drier - Google Patents

Abstract

PURPOSE: To enable a temperature descending speed in a sample chamber to be optionally changed by a method wherein a supplying or discharging amount of air in a sealingly closed tank is controlled by adjusting a degree of opening of an air discharging damper. CONSTITUTION: Air in a sample chamber 2 is heated by a heater 4 to cause its temperature to be increased, a forced convection flow is generated by a blower 6 and heated air with a high degree of cleanliness passed through a heat-resistant filter 7 is blown into a sample chamber 3. The heater 4 is operated in its ON-OFF states at a control section 1 to make a space keeping a constant temperature and dustless atmosphere in the sample chamber 3. A discharging hole 8 is located at a discharging side of the blower 6 showing a maximum positive pressure in a sealingly closed tank and also at a flowing-in side of the heat-resistant filter 7. A discharging damper 9 is operated such that its damper shaft is rotated and opened or closed. Thus, it can be operated at a full-closed or opened rate of 100% in respect to an effective sectional area of the discharging pipe. In turn, an air supplying hole 10 is located at a suction side of the blower 6 showing a low positive pressure of the sealingly closed tank and at a flowing-in side of the heater 4. There is provided a filter having some fine holes to prevent some rough particles etc., floating in the surrounding atmosphere from entering the drying device and then a suction resistance accompanied by the air supplying operation is restricted. A large amount of heated air in a sealingly closed tank under a full-opened state of the air discharging damper 9 is efficiently supplied or discharged, resulting in that a powerful cooling action can be attained.