EP3853404B1

EP3853404B1 - A laundry dryer

Info

Publication number: EP3853404B1
Application number: EP19748818.2A
Authority: EP
Inventors: Onur Hartoka; Gokhan SIR; Basak Arslan; Mehmet Kaya; Cigdem Ezgi SEVER
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2018-09-18
Filing date: 2019-07-31
Publication date: 2024-01-03
Anticipated expiration: 2039-07-31
Also published as: EP3853404A1; WO2020057839A1

Description

The present invention relates to a heat pump or conventional laundry dryer.
In conventional laundry dryers wherein the drying air is circulated through a closed cycle, the drying air moved by a fan is passed over the laundry inside the drum to be dehumidified and the water vapor in the air is condensed in the condenser. The drying air dehumidified in the condenser is then heated by being passed over the heater, and thus hot and dry air is delivered onto the laundry. In heat pump laundry dryers, the heat pump used for drying the laundry is composed of flow pipes wherein the refrigerant fluid flows, a compressor which provides the circulation of the refrigerant by pressurizing the same, an evaporator and a condenser. In the drying process, the drying air moved by the process fan is passed over the laundry. The condenser located in the heat pump functions as a heater and the evaporator as a condenser. The drying air is heated while passing over the condenser, delivered onto the laundry as heated and after dehumidifying the laundry, is condensed while passing over the evaporator.
In conventional and heat pump laundry dryers, a single motor is used for moving the drum and operating the fan which provides the air circulation. In this case during the operation of the motor the drum rotates clockwise or counterclockwise depending on the direction of the motor, and since the process fan is driven by the same motor, the process fan similarly rotates in both directions and provides air flow.
In heat pump or conventional laundry dryers, sufficient air flow is required for the systems, which perform the heating and dehumidification processes, to operate so as to carry out the drying process. In case of insufficient air flow, the heater in conventional laundry dryers and the compressor in heat pump laundry dryers are turned off and deactivated for security reasons, which in turn prolongs the drying process.
Since in laundry dryers the fan, which provides the air circulation, and the drum are driven by the same motor, the drum also has to rotate continuously while providing air flow. This causes the noise to increase and the delicate laundry to be worn down due to the mechanical effect caused by the rotation of the drum.
In the Patent Application No. US2017254014 (A1 ), in a laundry dryer two fans, one at the inlet of the drum and one at the outlet thereof, are provided so as to increase the flow rate of the air.
The aim of the present invention is the realization of a laundry dryer wherein the delicate laundry is prevented from being worn down and the drying process duration is shortened.
In the state of the art, European Patent Application No. EP2765235 discloses a laundry dryer comprising a control unit.
In the state of the art, German Patent Application No. DE2429078 discloses an automatic clothes drier comprises a horizontal-axis rotary perforated drum surrounded at a distance by a stationary casing, and a condenser for removing humidity from the drying air.
The above stated problem is solved by a laundry dryer as defined in claim 1 and by a conventional laundry dryer as defined in claim 7.
Preferred embodiments are defined in the dependent claims respectively.
The laundry dryer realized in order to attain the aim of the present invention comprises a heat pump system composed of an air circulation duct which enables the process air to be passed over the laundry in the drum, a first fan which moves the process air, a compressor which provides the circulation of the refrigerant, an evaporator and a condenser, or in the conventional type, a heater and a heat exchanger. In both types of laundry dryers, a main motor operates the drum and the first fan together. In the embodiment of the present invention, by means of a second fan disposed in the air circulation duct, the process air is continued to be circulated when the drum and the first fan are deactivated. The second fan is positioned at the outlet of the condenser in the heat pump laundry dryer, and at the outlet of the heater in the conventional laundry dryer.
The laundry dryer realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

Figure 1 - is the schematic view of a heat pump laundry dryer.
Figure 2 - is the schematic view of a conventional laundry dryer.

The elements illustrated in the figures are numbered as follows:

1.: Laundry dryer
2.: Drum
3.: Air circulation duct
4.: First fan
5.: Compressor
6.: Evaporator
7.: Condenser
8.: Main motor
9.: Auxiliary motor
10.: Second fan
11.: Control unit
12.: Conventional laundry dryer
13.: Heater
14.: Heat exchanger

The laundry dryer (1) comprises a body; a drum (2) wherein the laundry to be dried is placed; a heat pump system having an air circulation duct (3) which enables the process air to be passed over the laundry in the drum (2), a first fan (4) which is disposed in the air circulation duct (3) and which moves the process air, a compressor (5) which performs the refrigerant cycle, an evaporator (6) which enables the process air to be dehumidified and a condenser (7) which enables the process air to be heated; a main motor (8) which operates the drum (2) and the first fan (4) at the same time, thus rotating the drum (2) during the drying process while providing the circulation of the process air by means of the first fan (4); and a control unit (11) which regulates the drying process.
The laundry dryer (1) of the present invention comprises a second fan (10) which is disposed in the air circulation duct (3), which provides the continuity of the circulation of the process air in the drum (2) via the air circulation duct (3) when the drum (2) and the first fan (4) are deactivated during the drying process, and which is operated by an auxiliary motor (9) independently of the main motor (8).
In an embodiment of the present invention, the second fan (10) is positioned in the air circulation duct (3) at the outlet of the condenser (7) where the humidity of the process air is at the lowest level and the temperature of the process air is at the highest level. Moreover, the outlet of the condenser (7) is the point which least affects the flow rate of the process air. Thus, the adverse effect on the energy efficiency of the system when the second fan (10) is deactivated is minimized.
In the laundry dryer (1), the humid process air leaving the drum (2) passes through the evaporator (6) and the condenser (7) and then is directed to the drum (2) via the air circulation duct (3) by the first fan (4). The drum (2) and the fan (4) which enables the process air to be circulated in the air circulation duct (3) and the drum (2) are driven by the main motor (8). Therefore, when the drum (2) stops the first fan (4) also stops, and when the drum (2) rotates in the opposite direction, the first fan (4) also rates in the opposite direction. Particularly in delicate textile programs and quiet drying programs, the drum (2) is required to be stopped at intervals in order to reduce the movement thereof. In the embodiment of the present invention, when the drum (2) and the first fan (4) are stopped, the second fan (10) is activated by the auxiliary fan (9), thus resuming the process air flow. The second fan (10) moves the air with high temperature and low humidity at the outlet of the condenser (7), thus improving the drying performance. The delicate laundry is prevented from being worn down and is enabled to be quickly dried.
In an embodiment of the present invention, the control unit (11) executes a drying program wherein the second fan (10) is operated only when the drum (2) and the first fan (4) are stopped intermittently. Said drying program is used to prevent the laundry affected by the mechanical movement from being worn down and/or to consume less energy.
In an embodiment of the present invention, the control unit (11) executes a drying program wherein the second fan (10) is continuously operated and the drum (2) and the first fan (4) are stopped intermittently. Said drying program is used to air the laundry and remove odors and to decrease the formation of lint and the mechanical damage caused by the continuous rotation of the dry laundry with the drum (2).
In an embodiment of the present invention, the control unit (11) executes a drying program wherein the second fan (10) is continuously operated and the drum (2) and the first fan (4) are completely stopped. In this program, the air at high temperature and low flow rate is enabled to flow, and delicate laundry, which is excessively affected by the mechanical movement, is prevented from being worn down. In hygiene programs, only the second fan (10) is operated, thus performing the drying process at low flow rate.
In an embodiment of the present invention, the control unit (11) executes a drying program wherein the drum (2), the first fan (4) and the second fan (10) are continuously operated. This drying program is used to decrease the total drying time by increasing the flow rate of the process air and to quickly air the laundry and remove odors.
In another embodiment of the present invention, a conventional laundry dryer (12) comprises a drum (2) wherein the laundry to be dried is placed; an air circulation duct (3) which enables the process air to be passed over the laundry in the drum (2); a first fan (4) which is disposed in the air circulation duct (3) and which moves the process air; a heater (13) which heats the process air; a heat exchanger (14) which dehumidifies the process air; a main motor (8) which operates the drum (2) and the first fan (4) at the same time, thus rotating the drum (2) during the drying process while providing the circulation of the process air by means of the first fan (4); and a second fan (10) which is disposed in the air circulation duct (3), which is operated by an auxiliary motor (9) independently of the main motor (8), and which provides the continuity of the circulation of the process air in the drum (2) via the air circulation duct (3) when the drum (2) and the first fan (4) are deactivated.
In the conventional laundry dryer (12), the second fan (10) is disposed in the air circulation duct (3) at the outlet of the heater (13).
In the laundry dryer (1) of the present invention, the second fan (10) which is disposed in the air circulation duct (3) at the outlet of the condenser (7) enables the drying process to be carried out with minimum mechanical effect while not moving or barely moving the drum (2) during the drying of the delicate laundry. Thus, the laundry is prevented from being worn down. Energy consumption, total drying time and noises caused by the rotation of the drum (2) are decreased.

Claims

A laundry dryer (1) comprising a drum (2) wherein the laundry to be dried is placed, an air circulation duct (3) which enables the process air to be passed over the laundry in the drum (2), a first fan (4) which is disposed in the air circulation duct (3) and which moves the process air, a compressor (5) which performs the refrigerant cycle, an evaporator (6), a condenser (7), a main motor (8) which operates the drum (2) and the first fan (4), and a control unit (11),
- characterized by a second fan (10) which is disposed in the air circulation duct (3), which provides the continuity of the circulation of the process air in the drum (2) via the air circulation duct (3) when the drum (2) and the first fan (4) are deactivated during the drying process, and which is operated by an auxiliary motor (9) independently of the main motor (8).
A laundry dryer (1) as in Claim 1, characterized by the second fan (10) which is disposed in the air circulation duct (3) at the outlet of the condenser (7).
A laundry dryer (1) as in Claim 1 or 2, characterized by the control unit (11) which executes a drying program wherein the second fan (10) is operated only when the drum (2) and the first fan (4) are stopped intermittently.
A laundry dryer (1) as in Claim 1 or 2, characterized by the control unit (11) which executes a drying program wherein the second fan (10) is continuously operated and the drum (2) and the first fan (4) are stopped intermittently.
A laundry dryer (1) as in Claim 1 or 2, characterized by the control unit (11) which executes a drying program wherein the second fan (10) is continuously operated and the drum (2) and the first fan (4) are completely stopped.
A laundry dryer (1) as in Claim 1 or 2, characterized by the control unit (11) which executes a drying program wherein the drum (2), the first fan (4) and the second fan (10) are continuously operated.
A conventional laundry dryer (1) comprising a drum (2), an air circulation duct (3), a first fan (4), a main motor (8) which operates the drum (2) and the first fan (4) at the same time, a heater (13) which heats the process air, a heat exchanger (14) which dehumidifies the process air, characterized by a second fan (10) which is disposed in the air circulation duct (3), which provides the continuity of the circulation of the process air in the drum (2) via the air circulation duct (3) when the drum (2) and the first fan (4) are deactivated and which is operated by an auxiliary motor (9) independently of the main motor (8).
A conventional laundry dryer (12) as in Claim 7, characterized by the second fan (10) which is disposed in the air circulation duct (3) at the outlet of the heater (13).