Appliance for drying laundry

Patent metadata

Field	Value
Publication number	US-9534329-B2
Application number	US-201214370528-A
Country	US
Kind code	B2
Filing date	Dec 27, 2012
Priority date	Jan 5, 2012
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

An appliance for drying laundry ( 100 ) comprises an appliance cabinet ( 110 ), a laundry treatment chamber ( 105 ) inside the cabinet, and a drying air recirculation path ( 245 ) for causing recirculation of the drying air into/out from the laundry treatment chamber. The drying air recirculation path is at least partly external to the laundry treatment chamber. A drying air moisture condensing and heating system ( 215,220,225 ) located in the drying air recirculation path for dehydrating the moisture-laden drying air leaving the laundry treatment chamber and heating the dehydrated drying air before it re-enters into the laundry treatment chamber. The drying air moisture condensing and heating system comprises a first heat exchanger ( 215 ) and a second heat exchanger ( 220 ) of a heat pump ( 215,220,225,210 ), and further comprising a drying air propeller ( 250 ) inside the drying air recirculation path and a Joule-effect drying air heater ( 255 ), downstream the second heat exchanger, energizable for contributing to the heating of the drying air. The appliance includes a user interface ( 121 ) comprising a laundry treatment cycle selector ( 305 ) operable by a user for selecting a laundry treatment cycle, and a control unit ( 265 ) adapted to control the machine operation. The user interface comprises a command input means ( 315 ) operable by the user for imparting to the appliance an energization command to energize the Joule-effect heater. During the execution of the laundry treatment cycle selected by the user, the control unit causes the selective energization of the Joule-effect drying air heater based on the energization command imparted by the user.

First claim

The invention claimed is:

1. An appliance for drying laundry comprising an appliance cabinet, a laundry treatment chamber inside the cabinet, a drying air recirculation path for causing recirculation of the drying air into/out from the laundry treatment chamber, the drying air recirculation path being at least partly external to the laundry treatment chamber, a drying air moisture condensing and heating system located in the drying air recirculation path for dehydrating the moisture-laden drying air leaving the laundry treatment chamber and heating the dehydrated drying air before it re-enters into the laundry treatment chamber, wherein said drying air moisture condensing and heating system comprises a first heat exchanger and a second heat exchanger of a heat pump, and further comprising a drying air propeller inside the drying air recirculation path and a Joule-effect drying air heater, downstream the second heat exchanger, energizable for contributing to the heating of the drying air, wherein the appliance comprises a user interface comprising a laundry treatment cycle selector operable by a user for selecting a laundry treatment cycle, and a control unit adapted to control the machine operation, wherein the user interface comprises a command input means distinct from said laundry treatment cycle selector and operable by the user for imparting to the appliance an energization command to energize the Joule-effect heater, and in that during the execution of the laundry treatment cycle selected by the user, said control unit causes the selective energization of said Joule-effect drying air heater based on said energization command imparted by the user, so that the activation of the Joule-effect drying air heater is not systematical but instead decided by user by input of said energization command.

2. The appliance of claim 1 , wherein the user interface further comprises 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 control unit is adapted to cause the energization of the Joule-effect 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.

3. The appliance of claim 1 , further comprising a drying air temperature sensor located in said drying air recirculation path downstream said Joule-effect drying air heater, preferably substantially at the entrance into the laundry treatment chamber, and coupled to said 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.

4. The appliance of claim 3 , wherein said temperature threshold is dependent on the laundry treatment cycle selected by the user.

5. The appliance of claim 1 , wherein said heat pump comprises a variable-output compressor for the heat pump process fluid, and wherein the control unit is adapted to cause the appliance to perform at least one laundry treatment cycle in at least:
a first laundry drying mode, wherein the Joule-effect drying air 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
a second laundry drying mode, wherein the Joule-effect drying air heater is kept energized for at least an initial portion of the laundry treatment cycle and the compressor is driven to a second compressor mode after the Joule-effect drying air heater has been de-energized, wherein the second compressor mode comprises 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 laundry treatment cycle after the electric heater has been de-energized, the compressor power consumption and/or the compressor rotational speed and/or the 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.

6. The appliance of claim 5 , wherein for most of the laundry treatment cycle after the electric heater has been de-energized, the compressor power consumption and/or the compressor rotational speed and/or the 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.

7. The appliance of claim 5 , wherein for the whole remaining portion of the laundry treatment cycle after the electric heater has been de-energized, the compressor power consumption and/or the compressor rotational speed and/or the 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.

8. The appliance of claim 5 , wherein the control unit is further adapted to cause the laundry drying appliance to perform the at least one laundry treatment cycle according to at least a third laundry drying mode, wherein the Joule-effect drying air 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 laundry drying cycle after a time interval has elapsed from the compressor activation, the compressor power consumption and/or the compressor rotational speed and/or the 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.

9. The appliance of claim 5 , wherein said drying air propeller comprises a variable-speed fan, and wherein said control unit is adapted to drive the fan:
to a first fan mode having a speed course, in the first laundry drying mode, and
to a second fan mode having a speed course, in the second laundry drying mode,
wherein for at least a portion of the laundry treatment cycle, the speed of the second fan mode is higher than the speed of the first fan mode.

10. The appliance of claim 8 , wherein said second laundry drying mode is activatable by the user through said command input means, and said third laundry drying mode is activatable through said command input means or through a distinct actuation device.

11. The appliance of claim 8 , wherein said drying air propeller comprises a variable-speed fan, and wherein said control unit is adapted to drive the fan:
to a first fan mode having a speed course, in the first laundry drying mode, and
to a second fan mode having a speed course, in the second laundry drying mode,
wherein for at least a portion of the laundry treatment cycle, the speed of the second fan mode is higher than the speed of the first fan mode.

12. The laundry drying appliance of claim 11 , wherein the control unit is further adapted to drive the fan:
to a third fan mode having a speed course, in the third laundry drying mode, wherein for at least a portion of the laundry treatment cycle, the speed of the third fan mode is lower that the speed of the first fan mode.

13. A method of drying laundry in a laundry drying appliance comprising a cabinet, a laundr

Assignees

• Electrolux Home Products Corp Nv

Inventors

• Contarini Andrea
• Viero Massimo

Classifications

• D06F2105/28

  Electric heating · CPC title

• D06F58/28

  Textiles & Paper · mapped topic

• D06F58/24

  Condensing arrangements · CPC title

• D06F29/005 Primary

  the other separate apparatus being a drying appliance · CPC title

• D06F58/206

  Heat pump arrangements · CPC title