EP1989351B1

EP1989351B1 - Dryer

Info

Publication number: EP1989351B1
Application number: EP07712362.8A
Authority: EP
Inventors: Kemal Sarioglu; Tuba Kartal
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2006-03-01
Filing date: 2007-02-28
Publication date: 2016-12-07
Anticipated expiration: 2027-02-28
Also published as: WO2007099109A1; EP1989351A1

Description

The present invention relates to a dryer wherein the drying efficiency is enhanced by removing the moisture in the drying air passed over the laundry.
In laundry drying machines, usually the hot air, passed over the heater by means of the fan that activates the drying air, is directed into the drum and the drying air that is humidified and saturated depending on the amount of laundry in the drum is condensed by passing through the condenser and the condensed water is separated, providing to send hot and dry air over the laundry. The removal of moisture realized in the condenser directly affects the drying performance. Condensers of various designs for increasing the dehumidifying capability or heat pumps comprising refrigerant cycle elements like the compressor, evaporator, and condenser are utilized but problems are encountered in costs and space. In state of the art dryers, desiccant materials are also used through which the humid air is passed.
In the German patent document no. DE3626887 , dehumidifying materials are used to remove the moisture of the moisture-laden air in a laundry drier. Zeolite-based desiccants used are adsorptive materials The desiccant used makes possible the dehumidification of the air with a simultaneous heat recovery by slightly heating the dehumidified air. The desiccant is put in a container and the moisture-laden air is passed through this container so that the desiccant adsorbs the moisture of the process air. Under the desiccant container is a collection container and the water in the desiccant container is transferred thereto.
In the European patent document no. EP0777998 in a household appliance like the clothes dryer, the drying cycle air is passed through a closed system of a solid compound zeolite, alumina, activated carbon, silica gel container. The dehumidifying solid compound is capable of adsorbing the water molecules and generates heat during adsorption and desorbs when heated, that is separated from the water molecules it adsorbs. During the adsorption process in the desiccant container an air heating effect is created and an extra heater is used during the desorption process since the desiccant container has to be heated to high temperatures for removing the water collected on the desiccant material.
The aim of the present invention is the realization of a dryer wherein the drying efficiency is enhanced by extracting the moisture in the drying air which cannot be entirely condensed in the condenser.
The dryer realized in order to attain the aim of the present invention is explicated in the claims.
In the dryer of the present claim, the laundry to be dried is emplaced inside a drum and the drying air flowing in a circulation channel, after passing over the laundry, is condensed in a condenser, leaving its moisture. The humid air which is not entirely condensed in the condenser goes through a dehumidifier unit containing a material having a desiccant feature, situated at the exit of the condenser.
In the dryer of the present claim, also an electro-osmosis unit is utilized that provides to adsorb the moisture collected in the dehumidifying unit. The electro-osmosis unit creates an electro-osmotic power by means of the applied electric field and this power provides the water collected in the dehumidifier unit to be carried from one point to another to be removed from the dehumidifier unit. The moisture in the drying air is largely adsorbed and resent over the laundry thus enhancing the drying efficiency.
The dehumidifier unit can comprise an absorbent or adsorbent type desiccant material.
The electro-osmosis unit that provides the moisture removed by the dehumidifier unit to be discharged is composed of an electro-osmotic layer having a water permeable feature and electrodes that apply an electric field to this layer creating a pressure difference between the water inlet and outlet surfaces and maintain the water flow and a power source that transmits electricity to the electrodes.
The electro-osmosis unit and the dehumidifier unit can be produced in adjoining layers that cover the cross sectional area in the portion of the circulation channel at the exit of the condenser.
The 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 dryer.

The elements illustrated in the figures are numbered as follows:

1. Dryer
2. Drum
3. Circulation channel
4. Condenser
5. Heater
6. Dehumidifying unit
7. Electro-osmosis unit
8. DC power source
9. Layer
10. Anode
11. Cathode

The dryer (1) comprises a drum (2) inside which laundry to be dried is emplaced, a condenser (4) that removes the moisture in the air by condensation, a heater (5) that heats the drying air and a circulation channel (3) that provides the drying air to circulate between the drum (2), the condenser (4) and the heater (5).
The dryer (1) of the present invention comprises a dehumidifier unit (6) that provides to remove the moisture from the humid air flowing in the circulation channel (3) by means of a desiccant material capable of absorbing or adsorbing humidity and an electro-osmosis unit (7) adjoining the dehumidifier unit (6), that creates an electro-osmotic effect by the electric field, activates the collected water in the dehumidifier unit (6) by this effect and provides to remove it from the dehumidifier unit (6) by carrying from one point to another.
The electro-osmosis unit (7) comprises a DC power source (8) that generates electric current, an electro-osmotic layer (9) wherein electro-osmosis flow occurs between its surfaces and an anode (10) and a cathode (11) that transmit the electric current from the DC power source (8) to the layer (9), providing the water absorbed from one surface of the layer (9) to be conveyed to the other surface via the created electro-osmotic flow.
The anode (10) is situated on the surface of the layer (9) facing the dehumidifier unit (6), the cathode (11) is situated on the other surface and the positively charged ions move from the anode (10) to the cathode (11) with the electro-kinetic effect created by means of the electric field applied to the surfaces of the layer (9), providing the water to be conveyed from one surface of the layer (9) to the other surface.
In an embodiment of the present invention, the dehumidifier unit (6) is situated at the exit of the condenser (4) and the electro-osmosis unit (7) is situated behind the dehumidifier unit (6) such that they contact each other. The humid air exiting the condenser (4) leaves its moisture by passing through the dehumidifier unit (6) and since the moisture accumulated in the dehumidifier unit (6) is removed by the electro-osmosis unit (7), the dehumidifier unit (6) is provided to continuously preserve its dehumidifying capability, without reaching saturation.
In an embodiment of the present invention, the dehumidifier unit (6) and the electro-osmosis unit (7) are situated between the condenser (4) and the heater (5), depending on the direction of the drying air flow in the circulation channel (3). Consequently, the heating of the drying air when it is considerably dehumidified is possible, thereby delivering it into the drum (2).
In an embodiment of the present invention, the dehumidifier unit (6) is in the shape of sheet that covers the cross sectional area of the circulation channel (3) at the exit of the condenser (4). Consequently the moisture of all of the drying air passing through the circulation channel (3) can be removed.
In another embodiment of the present invention, the layer (9) is produced of a material like the plaster of Paris, silica gel, fiberglass etc. that has a desiccant feature as well as providing electro-osmotic flow by electro-kinetic effect.
In an embodiment of the present invention, the anode (10) and the cathode (11) are produced of an electrically conductive, carbon or plastic fiber reinforced material which also has a porous configuration for water-permeability such that the entrance and exit surfaces of the layer (9) are covered. In this embodiment, the anode (10) contacts the dehumidifier unit (6) and the moisture removed from the dehumidifier unit (6) passes to the layer (9) and to the cathode (11) after the anode (10) and is discharged.
The drying air that reaches the exit of the condenser (4), being partially dehumidified by the condenser (4), first passes through the dehumidifier unit (6) and meets with a lower pressure than its own pressure due to a feature of the desiccant material in the dehumidifier unit (6). The dehumidifier unit (6) draws in the water vapor by means of the lower pressure effect created by the desiccant material and the water molecules move along the dehumidifier unit (6). The water that passes through the dehumidifier unit (6), passes to the electro-osmosis unit (7) that operates like a pump due to the electric field created by the anode (10) at the inlet of the layer (9) and the cathode (11) at the outlet and the water entering through the anode (10) side of the layer (9) moves along the micro-channels situated in the layer (9), preaching the cathode (11) side and is later discharged out of the dryer (1) into the condensation container.
The moisture removal capacity of the electro-osmosis unit (7) is adjusted by varying the voltage applied by the DC power source (8). For example, when the voltage increases, the speed of the water moving forward n the electro-osmosis unit (7) also increases.
In the dryer (1) of the present invention the dehumidifier unit (6) and the electro-osmosis unit (7) operate together as a dehumidifier, the moisture contained in the drying air leaving the condenser (4) without being fully condensed is considerably removed from the drying air and consequently enhancing the drying efficiency by sending air over the laundry that is comparably drier than the conventional systems.
Use of a lesser amount of desiccant material is sufficient compared with implementations wherein desiccant materials are used to aid the condenser (4) or serve in place of the condenser (4), the dehumidifier unit (6) takes up less space, heaters that use a high amount of energy are not required for immediately removing the moisture from the desiccant material and consequently savings in energy is provided.

Claims

A dryer (1) comprising a drum (2) inside which laundry to be dried is emplaced, a condenser (4) that removes the moisture in the air by condensation, a heater (5) that heats the drying air and a circulation channel (3) that provides the drying air to be circulated between the drum (2), the condenser (4) and the heater (5) and characterized by a dehumidifier unit (6) that provides to remove the moisture from the humid air flowing in the circulation channel (3) by means of a desiccant material capable of adsorbing humidity and an electro-osmosis unit (7) adjoining the dehumidifier unit (6), that creates an electro-osmotic effect by the electric field, activates the collected water in the dehumidifier unit (6) providing to remove it from the dehumidifier unit (6) by carrying from one point to another.
A dryer (1) as in Claim 1, characterized by an electro-osmosis unit (7) comprising a DC power source (8), an electro-osmotic layer (9) wherein electro-osmosis flow occurs between its surfaces and an anode (10) and cathode (11) that transmit the electric current from the DC power source (8) to the layer (9), providing the water absorbed from one surface of the layer (9) to be conveyed to the other surface via the created electro-osmotic flow.
A dryer (1) as in Claim 1 or 2, characterized by a dehumidifier unit (6) situated at the exit of the condenser (4) and an electro-osmosis unit (7) that is situated behind the dehumidifier unit(6) such that they contact each other.
A dryer (1) as in Claim 1 or 2, characterized by a dehumidifier unit (6) and an electro-osmosis unit (7) that are situated between the condenser (4) and the heater (5) depending on the direction of the drying air flow in the circulation channel (3).
A dryer (1) as in any one of the above claims, characterized by a dehumidifier unit (6) that is in the shape of a sheet that covers the cross sectional area of the circulation channel (3) at the exit of the condenser (4).
A dryer (1) as in any one of the above claims, characterized by an electro-osmosis unit (7) comprising a layer (9) that has a desiccant feature as well as providing electro-osmotic flow by electro-kinetic effect.
A dryer (1) as in any one of the above claims, characterized by an electro-osmosis unit (7) comprising an anode (10) and a cathode (11) which are produced of an electrically conductive, carbon or plastic fiber reinforced material which also has a porous configuration for water-permeability, such that the entrance and exit surfaces of the layer (9) are covered.