Drying apparatus and methods and accessories for use therewith

• US 8,839,527 B2
• Filed: 02/21/2008
• Issued: 09/23/2014
• Est. Priority Date: 02/21/2006
• Status: Active Grant

• Current Assignee: Bora Appliances Limited, Joliet 2010 Limited
• Original Assignee: Goji Limited
• Inventors: Ben-Shmuel, Eran, Atzmony, Daniella, Shaham, Ginadi, Bilchinsky, Alexander
• Primary Examiner(s): Rinehart, Kenneth
• Assistant Examiner(s): SULLENS, TAVIA L
• Application Number:
  US12/527,883
• Publication Number:
  US 20100115785A1
• Time in Patent Office: 2,406 Days
• Field of Search: 342/55, 342/59, 34/95, 34260-265, 34 88- 89, 343/48, 345/97, 219/679, 219/685, 219/695, 219/700, 219/702, 219/716, 219/756, 219/759
• US Class Current: 34/260
• CPC Class Codes: D06F 2103/52 related to electric heating means, e.g. temperature or voltage
• CPC Class Codes: D06F 2103/64 Radiation, e.g. microwaves
• CPC Class Codes: D06F 2105/28 Electric heating
• CPC Class Codes: D06F 58/266 Microwave heating equipment
• CPC Class Codes: F26B 3/28 by radiation, e.g. from the sun
• CPC Class Codes: F26B 3/347 Electromagnetic heating, e.g. induction heating or heating using microwave energy
• CPC Class Codes: H05B 2206/045 Microwave disinfection, sterilization, destruction of waste...
• CPC Class Codes: H05B 2206/046 Microwave drying of wood, ink, food, ceramic, sintering of ceramic, clothes, hair
• CPC Class Codes: H05B 6/645 using temperature sensors
• CPC Class Codes: H05B 6/6458 using humidity or vapor sensors
• CPC Class Codes: H05B 6/6464 using weight sensors
• CPC Class Codes: H05B 6/6479 using steam
• CPC Class Codes: H05B 6/705 using microwave tuning
• CPC Class Codes: H05B 6/72 Radiators or antennas
• CPC Class Codes: H05B 6/80 Apparatus for specific applications stoves or ranges F24C7/02

Abstract

A method of drying an object comprising, providing an object into an RF cavity; applying broadband RF energy to the object in controlled manner which keeps the object within a desired temporal temperature schedule and within a desired spatial profile; and terminating the drying when it is at least estimated that a desired drying level is achieved.

Claims

1. A method of drying an object in a cavity using RF energy radiation, the method comprising:

applying RF energy to the object;

obtaining a spectral image, comprising input efficiency to the cavity as a function of frequency, based on coupled power between first and second antennas; and

adjusting the application of RF energy based on the spectral image.

2. The method according to claim 1, wherein the RF energy is radiated to the object through a plurality of RF feeds.

3. The method according to claim 1, further comprising varying an air flow about the object to control a temperature of the object.

4. The method according to claim 1, further comprising cooling an air flow provided to the object.

5. The method according to claim 1, further comprising controlling a drying rate of the object by varying an air flow provided to the object while maintaining a temperature of the object.

6. The method according to claim 1, wherein the applying the RF energy comprises utilizing a passive source in the cavity.

7. The method according to claim 1, wherein the spectral image includes a scan of dissipation of RF energy at different frequencies.

8. The method according to claim 1, wherein the applying is performed through at least the first and second antennas.

9. The method according to claim 1, wherein the applying the RF energy comprises applying the RF energy through at least the first and second antennas, and delivering energy to each of the at least first and second antennas at a different time.

10. The method of claim 9, further comprising dynamically controlling phases of signals emitted through each of the first and second antennas.

11. The method according to claim 1, further comprising controlling a rate of drying of the object.

12. The method according to claim 11, wherein the controlling the rate of drying comprises modifying the rate of drying while maintaining a temperature of the object within 10 degrees Celsius.

13. The method according to claim 1, wherein the spectral image comprises a net power efficiency as a function of frequency.

14. The method of claim 13, wherein the net power efficiency includes a portion of input power that is not output from the cavity as coupled power or reflected power.

15. The method according to claim 1, wherein the adjusting the application of RF energy based on the spectral image comprises adjusting at least one of:

a transmission frequency, transmission power, or a transmission time.

16. The method according to claim 15, wherein the adjusting the transmission power comprises adjusting the transmission power at a plurality of transmitted frequencies.

17. The method according to claim 1, further comprising forcing intaken air through a path configured to contact the object with the intaken air, and controlling the RF energy and air heating to maintain drying of the object based on a predetermined drying profile.

18. The method according to claim 17, wherein the drying profile comprises one or more of:

a time period for drying, a maximum agitation rate, or a final dryness.

19. The method according to claim 1, further comprising one or more of:

controlling air temperature in the cavity, controlling air pressure in the cavity, or agitating the object.

20. The method according to claim 19, further comprising agitating the object to promote air contact between the object and ambient air.

21. The method according to claim 1, wherein the RF energy comprises energy at a plurality of frequency bands.

22. The method according to claim 21, wherein the adjusting the application of RF energy comprises varying an intensity of energy corresponding to at least one frequency.

23. The method according to claim 21, wherein the adjusting the application of RF energy based on the spectral image comprises varying an input power corresponding to at least one frequency.

24. The method according to claim 1, further comprising terminating drying when an estimated drying level associated with the object corresponds to a desired drying level.

25. The method according to claim 24, wherein the desired drying level is selectable over a range of 70%-10% humidity.

26. The method according to claim 24, wherein the desired drying level is between 20% and 30% moisture content.

27. The method according to claim 24, wherein the estimated drying level is obtained by measuring a drying level of the object.

28. The method according to claim 27, wherein the measuring the drying level comprises measuring an RF energy absorption by the object.

29. The method according to claim 1, wherein the object comprises at least one item of textile.

30. The method according to claim 29, wherein the object comprises a plurality of clothing items.

31. The method according to claim 30, wherein each clothing item of the plurality of clothing items is associated with a different drying instruction.

32. A dryer, comprising:

a cavity to receive at least one object to dry;

at least one RF source configured to radiate RF energy into the cavity; and

a controller configured to;

obtain a spectral image comprising input efficiency to the cavity as a function of frequency, based on coupled power between first and second antennas; and

control the at least one RF source to dry the object based on the spectral image.

33. The dryer according to claim 32, further comprising a frequency sweeper which sweeps a frequency of the RF energy radiated by the first and second antennas.

34. The dryer according to claim 32, further comprising a plurality of RF feeds located in the cavity.

35. The dryer according to claim 32, further comprising one or more agitators to move the object within the cavity.

36. The dryer according to claim 32, further comprising a room temperature fabric drying setting and a fabric sterilization setting.

37. The dryer according to claim 32, wherein the controller controls the dryer to maintain a temperature of the object at below 50 degrees Celsius.

38. The dryer according to claim 32, further comprising a circuit for determining humidity of the object based on RF absorption by the object.

39. The dryer according to claim 32, further comprising desiccant material located in the cavity.

40. The dryer according to claim 32, further comprising at least one clothes treating material located in the cavity.

41. The dryer according to claim 32, wherein the controller is further configured to vary an input power corresponding to at least one frequency based on the spectral image.

42. The dryer according to claim 32, wherein the spectral image includes a scan of dissipation of RF energy at different frequencies.

43. The dryer according to claim 32, wherein the RF energy is radiated into the cavity via at least the first and second antennas.

44. The dryer of claim 32, wherein the controller is configured to cause RF energy delivery to each of the first and second antennas at differing times.

45. The dryer of claim 44, wherein the controller is further configured to dynamically control phases of signals emitted through each of the first and second antennas.

46. The dryer according to claim 32, wherein the controller is further configured to adjust, based on the spectral image, at least one of:

a transmission frequency, transmission power, or a transmission time.

47. The dryer according to claim 46, wherein the controller is configured to adjust the transmission power at a plurality of transmitted frequencies.

48. The dryer according to claim 32, wherein the dryer is configured as a clothes dryer.

49. The dryer according to claim 48, further including a control panel with settings for drying clothes of various fabrics, the settings being fed to the controller.

50. The dryer according to claim 32, wherein the spectral image comprises a net power efficiency as a function of frequency.

51. The dryer of claim 50, wherein the net power efficiency includes a portion of input power that is not output from the cavity as coupled power or reflected power.

52. The dryer according to claim 32, further comprising a forced air intake having a path configured to contact the object with intaken air.

53. The dryer according to claim 52, wherein the controller is configured to control the RF energy and air heating to maintain drying of the object based on a predetermined drying profile.

54. The dryer according to claim 53, wherein the drying profile comprises one or more of:

a time period for drying, a maximum agitation rate, or a final dryness.