WO2014056787A1

WO2014056787A1 - A household appliance wherein dessicant is used in the drying step

Info

Publication number: WO2014056787A1
Application number: PCT/EP2013/070642
Authority: WO
Inventors: Yusuf YUSUFOGLU; Ali UNLUTURK; Yusuf Koc
Original assignee: Arcelik Anonim Sirketi
Priority date: 2012-10-11
Filing date: 2013-10-03
Publication date: 2014-04-17
Also published as: EP2906100A1; AU2013329721A1; AU2013329721B2

Abstract

The present invention relates to a household appliance (1) comprising a tub (2) wherein the washing and/or the drying process is performed, an inlet port (3) providing the entry of air into the tub (2), an outlet port (4) providing the air in the tub (2) to be discharged outside, a channel (5) extending between the inlet port (3) and the outlet port (4) so as to remain outside the tub (2), a fan (6) disposed on the channel (5), a chamber (8) situated on the channel (5), a heater (7) disposed inside or in the vicinity of the chamber (8) and a desiccant (9) that is situated inside the chamber (8).

Description

A HOUSEHOLD APPLIANCE WHEREIN DESSICANT IS USED IN THE DRYING STEP

The present invention relates to a household appliance the energy consumption of which is decreased.

In household appliances like the dishwasher and dryer, the use of zeolite as the desiccant material, especially as the reversible desiccant material, is known for the aim of increasing the drying effectiveness and providing energy saving.

In these state of the art embodiments, the dishwasher comprises a chamber housing the zeolite, that is connected to the washing tub with an inlet and an outlet. In the main washing step, while the wash water is heated by operating the heater disposed in the vicinity of the chamber, the air received from inside the washing tub by operating the fan is passed over the chamber. In the main washing step, the zeolite releases the retained moisture and thus completes its regeneration. In the drying step, the humid air sucked from the washing tub by means of the fan, is confined by the zeolite that has completed its regeneration in the main washing step while passing through the chamber and that has become usable again. An air circulation is created in the drying step by directing the dehumidified processing air to the washing tub again.

The zeolite has to be heated to high temperatures (200°C) by means of an additional heater disposed inside or in the vicinity thereof so as to become usable again in the next drying step by completing its regeneration. The heater operated during this process results in the increase of energy consumption. In the situation sufficient temperatures are not reached for the regeneration of the zeolite, the dish drying performance decreases since the desiccation efficiency of the zeolite decreases. Furthermore, the need for using materials resistant to high regeneration temperatures increases the cost of raw materials.

In the state of the art German Patent Application No. DE10353774, a dishwasher is explained wherein the air is passed over the desiccant in the drying step.

The aim of the present invention is the realization of a household appliance, the energy consumption of which is decreased.

The household appliance realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof, comprises a tub wherein the drying and/or washing processes are performed, an inlet port providing the entry of air into the tub, an outlet port providing the exit of the air from the tub, a channel providing the formation of a closed air cycle between the inlet port and the outlet port, a fan situated on the channel, a chamber disposed on the channel, a heater placed near the chamber, and a desiccant situated inside the chamber, which is super absorbent polymer.

The humid air received from inside the tub by means of the fan is delivered to the chamber containing the desiccant and after leaving its moisture to the desiccant and being heated by means of the thermophysical properties of the desiccant, is redirected into the tub again. By means of this process, an efficient drying process is realized by evaporating the water on the dishes. The desiccant reaching the saturation point during desiccation is regenerated in the next washing step by means of a heater disposed in the vicinity thereof and becomes usable again.

In an embodiment of the present invention, the desiccant which is a super absorbent polymer, is petrochemical based and is formed by synthesizing any binary combinations of monomers like acrylic, acrylic acid, acrylic acid salts, acrylamide (AM), AMPS (2-acrylamido-2 methylpropanesulfonic acid), methacrylic acid with crosslinkers. Especially the acrylic based desiccants are preferred since the efficiency-cost ratio is high.

In an embodiment of the present invention, the desiccant which is a super absorbent polymer is biomodified. The biomodified desiccants are formed by crosslinking polysaccharide biopolymers like chitosan, cellulose, starch with biopolymer derivatives like CMC (carboxymethyl cellulose). Consequently, energy saving is realized by the use of a greener desiccant.

In an embodiment of the present invention, the desiccant which is a super absorbent polymer is entirely natural based. For example, the desiccant is formed as a result of cross linking cellulose with citric acid.

In an embodiment of the present invention, the desiccant is in granule form. Due to its granulated configuration, moisture can be retained more easily.

In an embodiment of the present invention, the regeneration temperature of the desiccant is between 50°C and 100°C. The regeneration duration and the thermal energy required for regeneration decrease thanks to the property of the desiccant being able to be regenerated at low temperatures. The regeneration process can be completed by utilizing the heater that heats the washing tub without using an additional heater. Furthermore, the need for using high temperature resistant components is eliminated and thus material cost is reduced.

In an embodiment of the present invention, the desiccation capacity of the desiccant is approximately fifty percent of its mass. Thus, a smaller amount of desiccant use is sufficient and the volume of the household appliance is used more effectively.

In an embodiment of the present invention, the glass transition temperature of the desiccant is between 20°C and 40°C. The desiccation capacity of the desiccant with high flexibility and low glass transition temperature is high.

In an embodiment of the present invention, the chamber has a flexible configuration. Thus, the chamber can expand during desiccation to compensate the increased desiccant volume.

In an embodiment of the present invention, the chamber is produced from a material with high thermal conductivity. Consequently, heat loss during heat transfer from the heater to the desiccant is decreased.

In an embodiment of the present invention, the heater is disposed at a place near the chamber, in a direction perpendicular to the air flow. Thus, almost all desiccant particles are facilitated to be regenerated since a homogeneous heat distribution is provided inside the chamber. The total desiccation capacity of the desiccant increases in the next drying step and hence a more effective drying is provided.

By means of the present invention, energy is saved during the regeneration process by using a super absorbent polymer as the desiccant. Furthermore, material costs decrease since the requirement of using material that is resistant to high regeneration temperature is eliminated.

The household appliance 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 the household appliance of the present invention.

The elements illustrated in the figure are numbered as follows:

Household appliance
Tub
Inlet port
Outlet port
Channel
Fan
Heater
Chamber
Desiccant

The household appliance (1) comprises a tub (2) wherein the washing and/or the drying process is performed, an inlet port (3) providing the entry of air into the tub (2), an outlet port (4) providing the air in the tub (2) to be discharged outside, a channel (5) extending between the inlet port (3) and the outlet port (4) so as to remain outside the tub (2), a fan (6) disposed on the channel (5), a chamber (8) situated on the channel (5), a heater (7) disposed inside or in the vicinity of the chamber (8) and a desiccant (9) that is situated inside the chamber (8). The humid air received from the tub (2) by means of the inlet port (3) is carried inside the channel (5) and directed to the chamber (8) containing the desiccant (9) by means of the fan (6). Heat is emanated while moisture, carried by air, is bonded with the desiccant (9) due to the thermophysical property of the desiccant (9). The air, that is dehumidified and the temperature of which increases due to the heat emanated during desiccation, is again directed into the tub (2). By means of this process, an effective drying process is realized by evaporating the water on the dishes. The desiccant (9) reaching the saturation point during desiccation is regenerated by means of a heater (7) disposed in the vicinity thereof in the next washing step and becomes usable again.

The desiccant (9) of the present invention is a super absorbent polymer. The widespread use of super absorbent polymers in child and adult diapers is known. The super absorbent polymers are materials that emanate heat while retaining moisture until the saturation point and that need to be regenerated upon reaching the saturation point to be able to retain moisture again. The heat requirement of super absorbent polymers is low for this regeneration process which is endothermic. The necessity of using a powerful heater (7) for regeneration is eliminated and hence energy consumption decreases since the super absorbent polymers complete their regeneration at low temperatures. It is possible to retain the moisture contained in the processing air by using a smaller amount of super absorbent polymer since the desiccation capacity of super absorbent polymers is high relative to their unit weights. Therefore, the super absorbent polymer occupies less space inside the chamber (8) and the area around the chamber (8) can be used more effectively since the volume of the chamber (8) is decreased.

In an embodiment of the present invention, the desiccant (9), which is a super absorbent polymer, is a synthetic/ petrochemical based material formed by crosslinking any binary combination of monomers like acrylic, acrylic acid, acrylic acid salts and acrylamide (AM), AMPS (2-acrylamido-2 methylpropanesulfonic acid).

In an embodiment of the present invention, the desiccant (9), which is a super absorbent polymer, is a biomodified material formed as a result of crosslinking biopolymers like chitosan, cellulose, starch with biopolymer derivatives like CMC (carboxymethyl cellulose). The biomodified desiccants (9) are preferred since they are ecological materials.

In an embodiment of the present invention, the desiccant (9), which is a super absorbent polymer, is an entirely natural based material that is formed by cross linking of cellulose with citric acid.

In an embodiment of the present invention, the desiccant (9) is in granule form. The granulated structure provides easier retaining of moisture.

In an embodiment of the present invention, the regeneration temperature of the desiccant (9), which is a super absorbent polymer, is between 50°C and 100°C. The requirement for a powerful heater (7) is eliminated since the desiccant (9) is regenerated at low temperatures. The need for using high temperature resistant material is eliminated and material cost is decreased since the temperature the components near the heater (7) are subjected to during the regeneration process decreases.

In an embodiment of the present invention, the desiccant (9) is a super absorbent polymer with a desiccation capacity that is approximately fifty percent of its mass. Thus, the use of a low weight desiccant (9) is sufficient and the material occupies less volume inside the chamber (8).

In an embodiment of the present invention, the glass transition temperature of the desiccant (9) is between 20°C and 40°C. The desiccant (9) with low glass transition temperature has high flexibility and thus the porous structure can retain more moisture by expanding.

In an embodiment of the present invention, the chamber (8) is formed from elastic material. Thus, the chamber (8) provides a flexible volume for the desiccant (9) that increases in volume during desiccation.

In an embodiment of the present invention, the chamber (8) is formed from a material with high thermal conductivity. Thus, the heat transfer between the heater (7) and the desiccant (9) inside the chamber (8) is realized with less energy loss and the regeneration efficiency of the desiccant (9) increases.

In an embodiment of the present invention, the heater (7) is disposed near the chamber (8) and in a direction perpendicular to the air flow. The heater (7) starts operating simultaneously with the fan (6) during the regeneration process. Heat transfer occurs by means of convection between the chamber (8) and the heater (7) which is disposed perpendicular to the fan (6) and near the chamber (8). Thus, the heat is provided to be distributed homogeneously inside the chamber (8), the regeneration efficiency of the desiccant (9) and hence desiccation capacity in the next drying step increases by means of the homogeneous heat distribution.

By means of the present invention, energy consumption is decreased by using the desiccant (9) with low regeneration temperature. Material costs are reduced since the requirement for using material that is resistant to high regeneration temperatures is eliminated. The volume of the chamber (8) is decreased since the desiccant (9) of the present invention can retain moisture up to 1000 times of its unit weight.

It is to be understood that the present invention is not limited to the embodiments disclosed above and a person skilled in the art can easily introduce different embodiments. These should be considered within the scope of the protection postulated by the claims of the present invention.

Claims

A household appliance (1) comprising a tub (2) wherein washing and/or drying process is performed, an inlet port (3) providing the entry of air into the tub (2), an outlet port (4) providing the air in the tub (2) to be discharged outside, a channel (5) extending between the inlet port (3) and the outlet port (4) so as to remain outside the tub (2), a fan (6) disposed on the channel (5), a chamber (8) situated on the channel (5) a heater (7) disposed inside or in the vicinity of the chamber (8) and a desiccant (9) that is situated inside the chamber (8), characterized by the desiccant (9) which is a super absorbent polymer.
The household appliance (1) as in Claim 1, characterized by the desiccant (9) which is a synthetic/petrochemical based super absorbent polymer formed by synthesizing any binary combination of monomers for example like acrylic, acrylic acid, acrylic acid salts and acrylamide (AM), AMPS (2-acrylamido-2 methylpropanesulfonic acid) with cross linkers.
The household appliance (1) as in Claim 1, characterized by the desiccant (9) which is a biomodified super absorbent polymer formed as a result of synthesizing biopolymers like chitosan, cellulose, starch and biopolymer derivatives like CMC (carboxymethyl cellulose) with cross linkers.
The household appliance (1) as in Claim 1, characterized by the desiccant (9) which is an entirely natural based super absorbent polymer formed by cross linking cellulose with citric acid.
The household appliance (1) as in any one of the above Claims, characterized by the desiccant (9) that is in granule form.
The household appliance (1) as in any one of the above claims, characterized by the desiccant (9), the regeneration temperature of which is between 50°C and 100°C.
The household appliance (1) as in any one of the above claims, characterized by the desiccant (9) with a desiccation capacity that is approximately fifty percent of its mass.
The household appliance (1) as in any one of the above claims, characterized by the desiccant (9), the glass transition temperature of which is between 20°C and 40°C.
The household appliance (1) as in any one of the above claims, characterized by the chamber (8) that is produced from an elastic material.
The household appliance (1) as in any one of the above claims, characterized by the chamber (8) that is formed from a material with high thermal conductivity.
The household appliance (1) as in any one of the above claims, characterized by the heater (7) that is disposed near the chamber (8) and in a direction perpendicular to the air flow.