Development of a microwave clothes dryer: Interim report III

Technical Report · Wed Mar 01 04:00:00 EST 1995

OSTI ID:71606

Smith, R D ^[1]; Gerling, J E ^[2]

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1. Thermo Energy Corp., Palo Alto, CA (United States)
2. JG Microwave, Inc., Medford, OR (United States)

Drying clothes with microwave energy combined with conventional hot air can potentially speed the drying process, improve fabric care, and increase dryer efficiency. This report describes important steps taken toward commercialization, particularly conceptualization of a highly sensitive safety sensor system. Such a system would help surmount problems arising from the heating of tramp materials, including metal items and pocket butane lighters. Hazards testing of a laboratory prototype dryer with a 915-MHz power supply initially showed that plastic butane lighters and common small metal objects such as bobby pins, nails, and bread wrapper ties do not heat sufficiently to cause an ignition hazard. However, more in-depth testing of plastic lighters in the 3-kW, 915-MHz fields showed that, just as in 2450-MHz fields, the lighter posed significant hazards because it could release pressurized, combustible gas when the plastic was softened by heating. Wooden-sheathed graphite pencils could also heat to ignition in either 2450-MHz or 915-MHz fields. A detection and control system was then designed to circumvent this hazard by accurately detecting trace amounts of combustion products in the dryer exhaust. Tests in a laboratory apparatus showed that termination of microwave power was possible well before any ignition occurred.

• Research Organization: Electric Power Research Inst., Palo Alto, CA (United States); Thermo Energy Corp., Palo Alto, CA (United States); JG Microwave, Inc., Medford, OR (United States)
• Sponsoring Organization: Electric Power Research Inst., Palo Alto, CA (United States)
• OSTI ID: 71606
• Report Number(s): EPRI-TR--104988
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
CLOTHES DRYERS
COMMERCIAL SECTOR
DRYING
ENERGY CONSERVATION
HAZARDS
MICROWAVE EQUIPMENT
PERFORMANCE TESTING
RESIDENTIAL SECTOR