Dielectric dryer drum

• US 8,943,705 B2
• Filed: 05/20/2011
• Issued: 02/03/2015
• Est. Priority Date: 05/20/2011
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: COOL Dry, LLC
• Inventors: Wisherd, David S., Eisenberg, John A., D'Anna, Pablo E.
• Primary Examiner(s): Rinehart, Kenneth
• Assistant Examiner(s): MCCORMACK, JOHN PATRICK
• Application Number:
  US13/112,880
• Publication Number:
  US 20120291304A1
• Time in Patent Office: 1,355 Days
• Field of Search: 342/55, 342/58, 345/28, 342/59, 34245-247, 342/50, 342/54, 342/56, 34260-265, 219629-632, 219/635, 219/643
• US Class Current: 34/255
• CPC Class Codes: D06F 58/266 Microwave heating equipment
• CPC Class Codes: F26B 11/0495 with provisions for drying by electro-magnetic means, e.g. radiation, microwaves burner arrangements F26B11/028
• CPC Class Codes: F26B 3/343 in combination with convection

Abstract

A method for heating an object having a variable weight that includes a medium is provided. The method comprises: (A) placing the object having the variable weight including medium into an enclosure; (B) initiating a heating process by subjecting medium including the object having the variable weight to a variable AC electrical field; and (C) controlling the heating process. The object has substantially absorbed medium in a first “cool” state and therefore includes a maximum weight in the first “cool” state due to absorption of medium. The object is substantially free from medium in a second “heated” state due to substantial release of medium from the object, wherein the released medium is evaporated during the heating process. The heating process is completed when the object is substantially transitioned into the second “heated” state. The method further comprises using an air flow having an ambient temperature inside the enclosure to carry away the evaporated medium from the enclosure.

Claims

1. A method for heating an object having a variable weight that includes a medium, said method comprising:

placing said object including said medium into an enclosure comprising a rotating drum having at least one anode element and at least one cathode area;

wherein said object absorbs said medium in a first “

cool”

state, and said object includes a maximum weight in said first “

cool”

state due to absorption of said medium;

initiating a heating process by capacitively coupling said object to an AC electrical field originated from an RF power source;

wherein said object including said medium transitions into a second “

heated”

state in which there is less medium than in said “

cool”

state due to release of said medium from said object; and

controlling said heating process by taking real time measurements and by controlling RF parameters in real time based upon said measurements;

wherein;

said heating process is completed when said object is transitioned into said second “

heated”

state; and

said parameters are selected from the group of parameters consisting of an RF voltage magnitude and envelope wave shape, an applied RF current magnitude and envelope wave shape, phase of RF voltage versus current, and voltage standing wave ration.

4. The method of claim 1 further comprising using an air flow having an ambient temperature inside said enclosure to carry away an evaporated state of said medium from said enclosure.

5. The method of claim 1, wherein said placing step further comprises:

selecting said object from the group consisting of a cloth substance;

a food substance;

a wood substance;

a plastic substance; and

a chemical substance.

6. The method of claim 1, wherein said placing step further comprises:

selecting said enclosure from the group consisting of a cylindrical cathode drum having at least one impellor; and

a cylindrical drum having at least one cathode end plate.

7. The method of claim 1, wherein said placing step further comprises selecting said enclosure material from the group consisting of a conductor;

a metal;

an insulator;

a dielectric insulator;

a ceramic insulator;

a plastic insulator;

a wooden insulator; and

a mixture of at least two drum materials.

8. The method of claim 1, wherein said placing step further comprises selecting said insulating material from the group consisting of glass;

plastic; and

ceramic.

9. The method of claim 1, wherein said initiating step further comprises;

rotating said drum with varying rotation speed to optimize RF coupling between the RF power source and the object.

10. The method of claim 9, wherein:

the object comprises items to be dried; and

said rotating comprises varying a direction of rotation of said drum to optimize RF coupling between the RF power source and the items by thwarting bunching of said items.

12. The method of claim 1 further comprising forming a connection from said cathode area to ground, said connection from the group consisting of a rotating capacitive connection and a non-rotating capacitive connection.

15. The method of claim 1 wherein the measurements are from the group of measurements consisting of RF impedance of the object including the medium;

temperature of the object including the medium; and

parameters of air flow.

16. The method of claim 1 further comprising inserting a variable tuning inductor between the RF power source and at least one anode element;

in order to optimize power transfer from the RF power source to the object including the medium.

2. A method for heating an object having a variable weight that includes a medium, said method comprising:

placing said object including said medium into a rotating enclosure;

wherein said object absorbs said medium in a first “

cool”

state; and

said object includes a maximum weight in said first “

cool”

state due to absorption of said medium;

initiating a heating process by subjecting said medium including said object to an AC electrical field originated from an RF power source;

wherein said object including said medium transitions into a second “

heated”

state in which there is less medium than in said “

cool”

state due to release of said medium from said object;

said rotating enclosure comprises at least one anode element and at least one cathode area; and

at least one said anode element is connected to said RF power source by a connector comprising a capacitive coupling; and

controlling said heating process by taking real time measurements of impedance of object, and by controlling RF parameters in real time based upon said measurements, wherein said heating process is completed when said object is transitioned into said second “

heated”

state.

13. The method of claim 2 further comprising selecting said capacitive coupling from the group consisting of a parallel plate and at least one concentric cylinder.

3. A method for heating an object having a variable weight that includes a medium;

said method comprising;

placing said object including said medium into a rotating enclosure;

wherein said object has absorbed said medium in a first “

cool”

state; and

said object includes a maximum weight in said first “

cool”

state due to absorption of said medium;

initiating a heating process by subjecting said medium including said object to an AC electrical field originated from an RF power source;

wherein said object including said medium transitions into a second “

heated”

state in which there is less medium than in said “

cool”

state due to release of said medium from said object;

said rotating enclosure comprises at least one anode element and at least one conductive cathode area;

the object comprises a load of clothing;

said medium comprises water;

at least one said anode element is connected to said RF power source by a connector comprising a capacitive coupling; and

said conductive cathode area of said enclosure is connected to ground by a capacitive coupling; and

controlling said heating process by taking real time measurements of impedance of the object, and by controlling RF parameters in real time based upon said measurements, wherein said heating process is completed when said object is transitioned into said second “

heated”

state.

14. The method of claim 3 further comprising minimizing a parasitic capacitance of said object including medium by mechanically staggering a plurality of coupling capacitors between at least one anode element and the RF power source.

11. A method for heating an object having a variable weight that includes a medium, said method comprising:

placing said object having said variable weight including said medium into a rotating enclosure;

wherein said object has absorbed said medium in a first “

cool”

state; and

wherein said object includes a maximum weight in said first “

cool”

state due to absorption of said medium;

initiating a heating process by subjecting said medium including said object to a variable AC electrical field introduced into the rotating enclosure by an anode located within the enclosure;

wherein said object including said medium transitions into a second “

heated”

state in which there is less medium than in said “

cool”

state due to release of said medium from said object; and

wherein said released medium is evaporated during said heating process;

selecting a connection from a conductive cathode area of said rotating enclosure to a ground return path of said RF power source from the group consisting of;

a rotating capacitive connection; and

a non rotating capacitive connection; and

optimizing said heating process by at least one of adjusting spacing between the anode and the object, and optimizing parasitic capacitance between the anode and the conductive cathode area.