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US 5,321,897 AGranted
Fabric dryer with arcing avoidance system
AssigneeMel Holst
InventorsMelvin Holst, Paul S. Payne
Life of this patent
Estimating the term…
Abstract
A fabric dryer employs microwave energy and an auxiliary air convection heater to heat the moisture in the fabric to be dried and provides for control of the microwave energy so that no arcing of metal or other electrically conductive parts occurs as the fabric becomes dryer. The fabric dryer has a controller that receives input from sensors and uses that input to progressively decrease the energy output from the magnetrons in such a manner to prevent arcing of all metal and other electrically conductive materials associated with the fabric, while also controlling the auxiliary air convection heater and an exhaust air recirculator to compensate for the decreased magnetron energy output.
Claims19
A fabric dryer comprising:
- (a) a drying chamber for receiving fabric laden with moisture;
- (b) an air intake duct for conducting air from the atmosphere into said drying chamber;
- (c) an air exhaust duct for conducting said air and moisture from said drying chamber into the atmosphere;
- (d) a source of microwave energy for generating heating energy at variable time-averaged rates to heat said moisture in said drying chamber;
- (e) control means for selectively said source of microwave energy so as to generate heating energy in the form of microwave pulses of progressively decreasing pulse widths;
- (f) said source of microwave energy comprising a magnetron having an electrical field-creating filament and means for heating said filament to maintain the temperature thereof substantially constant in the intervals between said pulses.
3 more elements
A fabric dryer comprising:
- (a) a drying chamber for receiving fabric laden with moisture;
- (b) an air intake duct for conducting air from the atmosphere into said drying chamber;
- (c) an air exhaust duct for conducting said air and moisture from said drying chamber into the atmosphere;
- (d) a source of microwave energy for generating heating energy at variable time-averaged rates to heat said moisture in said drying chamber;
- and
- (e) control means for selectively actuating said source of microwave energy so as to generate heating energy at progressively lower different time-averaged rates, said control means including means for setting respective predetermined times at which said source of microwave energy begins to generate heating energy at respective different time-averaged rates.
3 more elements
A fabric dryer comprising:
- (a) a drying chamber for receiving fabric laden with moisture;
- (b) an air intake duct for conducting air from the atmosphere into said drying chamber;
- (c) an air exhaust duct for conducting said air and moisture from said drying chamber into the atmosphere;
- (d) a source of microwave energy for generating heating energy at variable time-averaged rates to heat said moisture in said drying chamber;
- and
- (e) control means for selectively actuating said source of microwave energy so as to generate heating energy at progressively lower different time-averaged rates, said control means including means for setting respective predetermined durations during which said source of microwave energy generates energy at respective different time-averaged rates.
3 more elements
A fabric dryer comprising:
- (a) a drying chamber for receiving fabric laden with moisture;
- (b) an air intake duct for conducting air from the atmosphere into said drying chamber;
- (c) an air exhaust duct for conducting said air and moisture from said drying chamber into the atmosphere;
- (d) a source of microwave energy for generating heating energy at variable time-averaged rates to heat said moisture in said drying chamber;
- (e) control means for selectively actuating said source of microwave energy so as to generate heating energy at progressively lower different time-averaged rates;
- (f) an intake aircapability sensor for sensing the drying capability of air from the atmosphere which enters said air intake duct;
- and
- (g) said control means including means for variably actuating said source of micro wave energy at said different time-averaged rates in response to variations in the drying capability sensed by said intake air capability sensor.
5 more elements
A fabric dryer comprising:
- drying chamber for receiving fabric
- (a) a drying chamber for receiving fabric laden with moisture;
- (b) an air intake duct for conducting air from the atmosphere into said drying chamber;
- (c) an air exhaust duct for conducting said air and moisture from said drying chamber into the atmosphere;
- (d) a source of microwave energy for generating heating energy at variable time-averaged rates to heat said moisture in said drying chamber;
- (e) an exhaust temperature sensor for sensing variations in the temperature of said air after said air has been introduced into said drying chamber;
- (f) control means for selectively actuating said source of microwave energy so as to generate heating energy at progressively lower different time-averaged rates in response to the temperature sensed by said exhaust temperature sensor rising to a predetermined magnitude.
4 more elements
A fabric dryer comprising:
- (a) a drying chamber for receiving fabric laden with moisture;
- (b) an air intake duct for conducting air from the atmosphere into said drying chamber;
- (c) an air exhaust duct for conducting said air and moisture from said drying chamber into the atmosphere;
- (d) a source of microwave energy for generating heating energy at variable time-averaged rates to heat said moisture in said drying chamber;
- (e) a powered auxiliary source of heat separate from said source of microwave energy for heating said moisture in said drying chamber;
- and
- (f) control means for controlling said auxiliary source of heat variably in response to changes in said time-averaged rates.
4 more elements
A fabric dryer comprising:
- (a) a drying chamber for receiving fabric laden with moisture;
- (b) an air intake duct for conducting air from the atmosphere into said drying chamber;
- (c) an air exhaust duct for conducting said air and moisture from said drying chamber into the atmosphere;
- (d) a source of microwave energy for heating said moisture in said drying chamber;
- (e) a powered auxiliary source of heat separate from said source of microwave energy for heating said moisture in said drying chamber;
- (f) an exhaust condition sensor for sensing variations in the condition of said air after said air has been introduced into said drying chamber;
- and
- (g) control means for selectively actuating said source of microwave energy without actuating said auxiliary source of heat to heat said moisture in said drying chamber or, alternatively, actuating said source of microwave energy simultaneously with said auxiliary source of heat, in response to said condition sensed by said exhaust condition sensor.
5 more elements
A fabric dryer comprising:
- (a) a drying chamber for receiving fabric laden with moisture;
- (b) an air intake duct for conducting air from the atmosphere into said drying chamber;
- (c) an air exhaust duct for conducting said air and moisture from said drying chamber into the atmosphere;
- (d) means for recirculating air from said air exhaust duct into said drying chamber;
- (e) recirculation damper means for variably regulating the flow of air recirculated from said air exhaust duct into said drying chamber;
- (f) a powered source of heat for generating heating energy at variable time-averaged rates to heat said moisture in said drying chamber;
- and
- (g) control means for controlling said recirculation damper means variably in response to changes in said time-averaged rates.
5 more elements
Dependencies are inferred from the claim text.