EP2637545A1

EP2637545A1 - A dishwasher with reduced energy consumption

Info

Publication number: EP2637545A1
Application number: EP11778905.7A
Authority: EP
Inventors: Ismail Kokbiyik; Ugur Kan
Original assignee: Arcelik AS
Current assignee: Arcelik AS
Priority date: 2010-11-12
Filing date: 2011-11-04
Publication date: 2013-09-18
Also published as: WO2012062680A1

Abstract

The present invention relates to a dishwasher (1) comprising a tub (2) wherein the washing process in performed, a tub inlet (3) that provides air entrance into the tub (2), a tub outlet (4) providing the air in the tub (2) to be discharged, an air channel (5) located outside the tub (2), providing a closed air cycle between the tub outlet (4) and the tub inlet (3), a fan (6) disposed on the air channel (5) and providing the air in the tub (2) to be sucked, a sump (7) disposed below the tub (2) and wherein the liquid used during washing is collected, a heater (8) disposed outside the sump (7) and providing the washing liquid to be heated, a circulation pump (9) providing the circulation of the washing liquid between the sump (7) and the heater (8), a liquid circulation line (16) that provides the connection between the sump (7), the heater (8) and the circulation pump (9), and a dehumidifying unit (10) disposed on the air channel (5) and having a container (11), at least one desiccant material (12) disposed inside the container (11), an inlet port (13) which provides the air coming from the air channel (5) to be received into the container (11) and an outlet port (14) providing the air in the container (11) to pass to the air channel (5), and the energy consumption of which is reduced.

Description

[Title established by the ISA under Rule 37.2] A DISHWASHER WITH REDUCED ENERGY CONSUMPTION

The present invention relates to a dishwasher the energy consumption of which is reduced.
In the dishwasher washing programs, washing, rinsing and drying steps are performed respectively. In the washing step, after washing is performed with cold water in the first phase, the heater is operated and the washing liquid is heated. After the washing step is over, the rinsing step is performed in order to remove the washing liquid and the foam remaining on the dishes. The dishes washed in the rinsing step is first rinsed with cold water and then the hot rinsing step is performed in order to facilitate the drying step by increasing the temperature in the tub. In both of the water heating steps performed during the washing programs, a great amount of energy is consumed.
In order to reduce the energy consumption in dishwashers, drying elements comprising reversible type moisture adsorbent materials are used. Adsorbent materials can adsorb moisture up to the saturation point and emit heat to their surroundings as they adsorb moisture. In the state of the art, zeolite is used as moisture adsorbent in dishwashers. Humid air received from the tub by means of the fan is sent to the zeolite-comprising container and after heating up and leaving its moisture therein, the said air is again directed into the tub. By means of this process, the drying process is realized by vaporizing the water on the dishes without requiring the realization of the hot rinsing step.
Zeolite that fills its moisture adsorption capacity during the drying step is regenerated at the next washing step by being heated up to high temperatures by means of a heater placed therein or thereabout and becomes usable in the next drying step. The heater operated during this process leads to the increase of energy consumption.
In the state of the art European Patent Document No. EP358279, a dishwasher is described, comprising a zeolite container positioned around a pipe-type water heater. In this embodiment, the zeolite particles contact the heater directly. The residual heat occurring around the heater is used during the water heating process for zeolite regeneration.
The aim of the present invention is the realization of a dishwasher comprising a dehumidifying unit which provides the total energy consumption to be reduced.
The dishwasher realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof, comprises an air channel that is disposed outside the tub and that provides the creation of a closed air cycle between the tub outlet and the tub inlet, a sump which extends from the base of the tub towards the outside of the tub and wherein the liquid used during washing is collected, a heater that is disposed outside the sump and that provides the washing liquid to be heated, a circulation pump that provides the circulation of the washing liquid between the sump and the heater, a liquid circulation line that provides the connection between the sump, the heater and the circulation pump, and a dehumidifying unit disposed on the air channel.
In the dishwasher of the present invention, at least some portion of the liquid circulation line passes through the container so as to contact the desiccant material. The volume remaining between the liquid circulation line and the wall of the container is filled with the desiccant material.
In an embodiment of the present invention, the fan, the heater and the circulation pump are operated at approximately the same time just after the pre-washing step.
In another embodiment of the present invention, the fan and the circulation pump are operated just after the pre-washing step and the heater is operated some time after them.
In another embodiment of the present invention, an additional heater, which provides the desiccant material to be regenerated quickly, is used in the dehumidifying unit. The desiccant material particles saturated with moisture are heated by means of the additional heater centered inside the container and an effective regeneration is realized.
In another embodiment of the present invention, the heater is provided on the liquid circulation line, outside the container. The heater can be placed before or after the container with respect to the flow direction of water.
In another embodiment of the present invention, the heater is provided inside container, as embedded in the desiccant material. Thus, the residual heat the heater emits to its surroundings when operated is transmitted to the desiccant material particles by conduction.
In another embodiment of the present invention, the heater, the circulation pump and the additional heater are operated just after the first rinsing step is over and the fan is operated some time after them.
The desiccant material has reversible feature. Preferably zeolite is used as the desiccant material.
By means of the present invention, in the washing and rinsing steps, when the washing liquid is heated, an additional heat is provided by means of the desiccant material in the dehumidifying unit and the heater is operated for a shorter period of time. Moreover, some amount of the heat required for the regeneration of the desiccant material is provided by the heater that heats the washing liquid. Thus, the total energy consumption of the dishwasher is reduced.
The dishwasher 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 dishwasher of the present invention.
Figure 2 – is the schematic view of the dishwasher in an embodiment of the present invention.
The elements illustrated in the figures are numbered as follows:

Dishwasher
Tub
Tub inlet
Tub outlet
Air channel
Fan
Sump
Heater
Circulation pump
Dehumidifying unit
Container
Desiccant material
Inlet port
Outlet port
Additional heater
Liquid circulation line

The dishwasher (1) comprises a tub (2) wherein the washing process is performed, a tub inlet (3) that provides air entrance into the tub (2), a tub outlet (4) providing the air in the tub (2) to be discharged, an air channel (5) located outside the tub (2), providing a closed air cycle between the tub outlet (4) and the tub inlet (3), a fan (6) disposed on the air channel (5) and providing the air in the tub (2) to be sucked, a sump (7) disposed below the tub (2) and wherein the liquid used during washing is collected, a heater (8) disposed outside the sump (7) and providing the washing liquid to be heated, a circulation pump (9) providing the circulation of the washing liquid between the sump (7) and the heater (8), a liquid circulation line (16) that provides the connection between the sump (7), the heater (8) and the circulation pump (9), and a dehumidifying unit (10) disposed on the air channel (5) and having a container (11), a desiccant material (12) disposed inside the container (11), an inlet port (13) which provides the air coming from the air channel (5) to be received into the container (11) and an outlet port (14) providing the air in the container (11) to pass to the air channel (5).
The dishwasher (1) washing program consists of pre-washing, main washing, first rinsing, second rinsing and drying steps respectively. Hot liquid is used in the main washing and second rinsing steps and liquid of ambient temperature is used in the pre-washing and first rinsing steps. In the steps during which hot liquid is used, the circulation pump (9) and the heater (8) are operated in order to heat the liquid in the sump (7). The liquid desired to be heated is received from the sump (7) by means of the circulation pump (9), passed over the heater (8) and sent back to the sump (7). This process, which is realized on the liquid circulation line (16), continues until the liquid reaches the desired temperature.
The dishwasher (1) of the present invention comprises the liquid circulation line (16) at least one portion of which passes through the container (11) so as to contact the desiccant material (12). In the volume between the liquid circulation line (16) and the container (11), the desiccant material (12) is provided. Thus, heat transfer is provided between the desiccant material (12) particles in the container (11) and the washing liquid passing through the liquid circulation line (16) by means of conduction.
In an embodiment of the present invention, the fan (6), the heater (8) and the circulation pump (9) are operated at the beginning of the main washing step, just after the pre-washing step. After the pre-washing process is over, the washing liquid is heated by operating the heater (8) and the circulation pump (9). In the meantime, the fan (6) disposed on the air channel (5) is also operated and the air in the tub (2) is sucked. The air that enters the air channel (5) by exiting the tub (2) through the tub outlet (4) continues to move in the air channel (5) for a while and then is received into the dehumidifying unit (10) by passing through the inlet port (13). The humid air leaves its moisture on the desiccant material (12) by proceeding along the container (11). As the desiccant material (12) retains the moisture of the air, it emits heat due to its thermophysical feature. One part of the said heat is delivered into the tub (2) by means of the cycle air and the other part is transferred to the washing liquid by means of the desiccant material (12) particles contacting the liquid circulation line (16) from the outside. Thus, the washing liquid is heated more quickly and the heater (8) is operated for a shorter period of time. This reduces the energy consumption of the dishwasher (1).
In another embodiment of the present invention, the fan (6) and the circulation pump (9) are operated at the beginning of the main washing step, just after the pre-washing step, and the heater (8) is operated some time after the fan (6) and the circulation pump (9). When the fan (6) is operated, the desiccant material (12) emits heat by retaining the moisture of the air passing thereover. By means of the said heat, the temperature of the washing liquid passing through the liquid circulation line (16) is brought to a level and the heater (8) is operated after a while. Thus, the heater (8) is operated for a shorter period of time in order to bring the washing liquid to the desired temperature value and energy saving is provided.
The desiccant material (12) saturated with moisture during the washing step is required to be regenerated by being heated in order to be used again. The residual heat emitted from the heater (8) disposed around the container (11) is used for the regeneration process.
In another embodiment of the present invention, the heater (8) is disposed on the liquid circulation line (16) and outside the container (11) (Figure 1).
In another embodiment of the present invention, the heater (8) is provided inside container (11), as embedded in the desiccant material (12) (Figure 2). Thus, the residual heat the heater (8) emits to its surroundings when operated is transmitted to the desiccant material (12) particles by conduction.
In an embodiment of the present invention, the dehumidifying unit (10) comprises an additional heater (15) which provides the desiccant material (12) to be regenerated quickly. The additional heater (15) is disposed in the volume filled with the desiccant material (12) in the container (11). Thus, the desiccant material (12) is provided to be regenerated more homogeneously and quickly. In this embodiment, since almost all of the desiccant material (12) particles are regenerated, the total dehumidifying capacity and accordingly the amount of heat emitted during adsorption are preserved.
In another embodiment of the present invention, the heater (8), the circulation pump (9) and the additional heater (15) are operated at the beginning of the second rinsing step, just after the first rinsing step is over, and the fan (6) is operated some time after the heater (8), the circulation pump (9) and the additional heater (15). By operating the heater (8), the circulation pump (9) and the additional heater (15), on one hand the temperature of the desiccant material (12) in the container (11) is increased and on the other hand the temperature of the washing liquid is increased. After a while, the desiccant material (12) particles are regenerated by reaching the high temperature values required for regeneration. The desiccant material (12) can not retain moisture around the temperature values at which it is regenerated due to its structure. By means of the fan (6) operated in the meantime, the high amount of heat accumulating inside the container (11) is delivered into the tub (2) by convection and the temperate in the tub (2) increases. Thus, the heater (8), which heats the washing liquid in order to increase the temperature in the tub (2), is operated for a shorter period of time and energy saving is provided.
The desiccant material (12) has reversible feature. Preferably zeolite is used as the desiccant material (12).
By means of the present invention, in the washing and rinsing steps, when the washing liquid is heated, an additional heat is provided by means of the desiccant material (12) in the dehumidifying unit (10) and the heater (8) is operated for a shorter period of time. Moreover, some amount of the heat required for the regeneration of the desiccant material (12) is provided by the heater (8) that heats the washing liquid. Thus, the total energy consumption of the dishwasher (1) is reduced.
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 dishwasher (1) comprising a tub (2) wherein the washing process is performed, a tub inlet (3) that provides air entrance into the tub (2), a tub outlet (4) providing the air in the tub (2) to be discharged, an air channel (5) located outside the tub (2), providing a closed air cycle between the tub outlet (4) and the tub inlet (3), a fan (6) disposed on the air channel (5) and providing the air in the tub (2) to be sucked, a sump (7) disposed below the tub (2) and wherein the liquid used during washing is collected, a heater (8) disposed outside the sump (7) and providing the washing liquid to be heated, a circulation pump (9) providing the circulation of the washing liquid between the sump (7) and the heater (8), a liquid circulation line (16) that provides the connection between the sump (7), the heater (8) and the circulation pump (9), and a dehumidifying unit (10) disposed on the air channel (5) and having a container (11), a desiccant material (12) disposed inside the container (11), an inlet port (13) which provides the air coming from the air channel (5) to be received into the container (11) and an outlet port (14) providing the air in the container (11) to pass to the air channel (5), characterized by the liquid circulation line (16) at least one portion of which passes through the container (11) so as to contact the desiccant material (12).
A dishwasher (1) as in Claim 1, the washing program of which consists of pre-washing, main washing, first rinsing, second rinsing and drying steps respectively, characterized by the fan (6), the heater (8) and the circulation pump (9) operated at the beginning of the main washing step, after the pre-washing step.
A dishwasher (1) as in Claim 1, characterized by the fan (6) and the circulation pump (9) operated at the beginning of the main washing step, after the pre-washing step and the heater (8) operated some time after the fan (6) and the circulation pump (9).
A dishwasher (1) as in any one of the above Claims, characterized by the dehumidifying unit (10) comprising an additional heater (15) that provides the desiccant material (12) to be regenerated quickly.
A dishwasher (1) as in any one of the above Claims, characterized by the heater (8) disposed on the liquid circulation line (16) and outside the container (11).
A dishwasher (1) as in any one of the Claims 1 to 4, characterized by the heater (8) provided inside the container (11), as embedded in the desiccant material (12).
A dishwasher (1) as in Claim 6, characterized by the heater (8), the circulation pump (9) and the additional heater (15) operated at the beginning of the second rinsing step, just after the first rinsing step is over and the fan (6) operated some time after the heater (8), the circulation pump (9) and the additional heater (15).