Appliance for drying laundry

• US 9,359,714 B2
• Filed: 12/28/2012
• Issued: 06/07/2016
• Est. Priority Date: 01/05/2012
• Status: Active Grant

• Current Assignee: Electrolux Home Products Incorporated (AB Electrolux)
• Original Assignee: Electrolux Home Products Incorporated (AB Electrolux)
• Inventors: Contarini, Andrea, Viero, Massimo
• Primary Examiner(s): Gravini, Stephen M
• Application Number:
  US14/370,531
• Publication Number:
  US 20150040421A1
• Time in Patent Office: 1,257 Days
• Field of Search: 344/68, 345/24, 345/95, 346/01, 346/10, 68/5.C, 68/5.R, 68/19, 68/20, 813/9, 814/9, 815/9
• US Class Current: 1/1
• CPC Class Codes: D06F 2105/28 Electric heating
• CPC Class Codes: D06F 25/00 Washing machines with receptacles, e.g. perforated, having a rotary movement, e.g. oscillatory movement, the receptacle serving both for washing and for centrifugally separating water from the laundry and having further drying means, e.g. using hot air control of washing or of washing and drying D06F33/00, D06F34/00; domestic laundry dryers D06F58/00
• CPC Class Codes: D06F 29/005 the other separate apparatus being a drying appliance
• CPC Class Codes: D06F 58/203 Laundry conditioning arrangements
• CPC Class Codes: D06F 58/206 Heat pump arrangements
• CPC Class Codes: D06F 58/30 Drying processes controlling a series of operations in domestic laundry dryers D06F58/32

Abstract

An Appliance for drying laundry (100) includes a drying-air moisture-condensing system (215,220, 225) comprising a heat pump system with a first heat exchanger (215) for cooling the drying air and a second heat exchanger (220) for re-heating said drying air, and a variable-output compressor (210). At least one Joule-effect heater (255) is located downstream of the heat pump heat exchangers for boosting the heating of the drying air. The appliance can perform at least one drying cycle in: at least a first drying mode, wherein the heater is kept de-energized and the compressor is driven to a first compressor mode having a compressor power consumption course and/or a compressor rotational speed course and/or a frequency course of the supply current/voltage of the compressor motor, and at least a second drying mode, wherein the heater is kept energized for at least an initial portion of the drying cycle and thereafter it is kept de-energized, and the compressor is driven to a second compressor mode comprising a compressor power consumption course and/or a compressor rotational speed course and/or a frequency course of the supply current/voltage of the compressor motor. For at least a portion of the drying cycle after the electric heater has been de-energized, a compressor power consumption and/or a compressor rotational speed and/or a frequency of the supply current/voltage the compressor of the second compressor mode is/are higher than the one/s of the first compressor mode.

Claims

1. An appliance for drying laundry, comprising a drying-air moisture-condensing system comprising a heat pump system with a first heat exchanger for cooling the drying air and causing condensation of the moisture contained therein, and a second heat exchanger for heating the de-moisturized drying air, and a variable-output compressor, and at least one Joule-effect heater located downstream of the heat pump heat exchangers for boosting the heating of the drying air, wherein the appliance is adapted to perform at least one laundry drying cycle in:

at least a first drying mode, wherein the Joule-effect heater is kept de-energized and the compressor is driven to a first compressor mode having a compressor power consumption course and/or a compressor rotational speed course and/or a frequency course of the supply current/voltage of the compressor motor, and

at least a second drying mode, wherein the Joule-effect heater is kept energized for at least an initial portion of the drying cycle and thereafter it is kept de-energized, and the compressor is driven to a second compressor mode, the second compressor mode comprising a compressor power consumption course and/or a compressor rotational speed course and/or a frequency course of the supply current/voltage of the compressor motor,

wherein for at least a portion of the drying cycle after the electric heater has been de-energized, a compressor power consumption and/or a compressor rotational speed and/or a frequency of the supply current/voltage of the compressor of the second compressor mode is/are higher than the one/s of the first compressor mode.

2. The appliance of claim 1, wherein for most or the whole of said portion of the drying cycle after the electric heater has been de-energized, the compressor power consumption and/or a compressor rotational speed and/or a frequency of the supply current/voltage of the compressor of the second compressor mode is/are higher than the one/s of the first compressor mode.

3. The appliance of claim 2, wherein said portion of the drying cycle after the electric heater has been de-energized is 30%-100%.

4. The appliance of claim 1, wherein the appliance is adapted to perform the at least one drying cycle according to at least a third drying mode, wherein the Joule-effect heater is kept de-energized and the compressor is driven to a third compressor mode having a compressor power consumption course and/or a compressor rotational speed course and/or a frequency course of the supply current/voltage of the compressor motor, wherein for at least a portion of the drying cycle after a time interval has elapsed from the compressor activation, a compressor power consumption and/or a compressor rotational speed and/or a frequency of the supply current/voltage of the compressor of the third compressor mode is/are lower than the one/s of the first compressor mode.

5. The appliance of claim 4, wherein said time interval elapsed from the compressor activation is at least the time interval necessary to the heat pump to reach a steady-state operation after it is started.

6. The appliance of claim 5, wherein said at least a portion of the drying cycle after a time interval has elapsed from the compressor activation is 30%-100% of the drying cycle after a time interval has elapsed from the compressor activation.

7. The appliance of claim 1, comprising a user interface may including a command input means actuatable by a user to impart to the appliance an energization command to energize the Joule-effect heater.

8. The appliance of claim 7, comprising a control unit adapted to automatically activate said second drying mods when the user actuates said command input means to impart to the appliance said energization command.

9. The appliance of claim 7, wherein the user interface comprises a laundry treatment cycle selector, distinct from said command input means, through which the user can select the proper laundry treatment cycle in dependence of the type of textiles to be treated.

10. The appliance of claim 9, wherein the user interface further includes an appliance start input means operable by the user to cause the appliance start the execution of the laundry treatment cycle selected by the user via the cycle selector, and wherein the appliance is adapted to cause the energization of the electric drying air heater if said energization command imparted by the user is imparted before the user activation of said start input means to start the laundry treatment cycle execution.

11. The appliance of claim 4, wherein said third drying mode is activatable by the user by actuating a command input means.

12. The appliance of claim 1, further comprising a drying air temperature sensor located downstream the Joule-effect heater, said temperature sensor being coupled to an appliance control unit to provide thereto measures about the temperature of the drying air entering into the laundry treatment chamber, wherein the control unit is adapted to compare the measures of the drying air temperature with at least one predetermined temperature threshold and to automatically de-energize the Joule-effect drying air heater when the temperature threshold is reached.

13. The appliance of claim 1, comprising at least one drying air variable-speed fan for promoting the recirculation of the drying air, and wherein the appliance is adapted to drive the fan to a first fan mode having a speed course in the first drying mode, and to a second fan mode having a speed course in the second drying mode, wherein for said at least a portion of the drying cycle, the speed of the second fan mode is higher than the speed of the first fan mode.

14. The appliance of claim 13, further adapted to drive the fan to a third fan mode having a speed course in the third drying mode, wherein for said at least a portion of the drying cycle, the speed of the third fan mode is lower that the speed of the first fan mode.

15. A method of drying laundry in an appliance for drying laundry comprising a drying-air moisture-condensing system comprising a heat pump system with a first heat exchanger for cooling the drying air and cause condensation of the moisture contained therein, and a second heat exchanger for heating the de-moisturized drying air, and a variable-output compressor, and at least one Joule-effect heater located downstream the heat pump heat exchangers for boosting the heating of the drying air, the method comprising performing at least one laundry drying cycle in:

at least a first drying mode, wherein the Joule-effect heater is kept de-energized and the compressor is driven to a first compressor mode having a compressor power consumption course

and/or a compressor rotational speed course and/or a frequency course of the supply current/voltage of the compressor motor, or

at least a second drying mode, wherein the Joule-effect heater is kept energized for at least an initial portion of the drying cycle and thereafter it is kept de-energized, and the compressor is driven to a second compressor mode, the second compressor mode comprising a compressor

power consumption course and/or a compressor rotational speed course and/or a frequency course of the supply current/voltage of the compressor motor,

wherein for at least a portion of the drying cycle after the electric heater has been de-energized, a compressor power consumption and/or a compressor rotational speed and/or a frequency of the supply current/voltage of the compressor of the second compressor mode is/are higher than the one/s of the first compressor mode.