WO2014102739A1

WO2014102739A1 - Dishwasher machine and washing cycle

Info

Publication number: WO2014102739A1
Application number: PCT/IB2013/061362
Authority: WO
Inventors: Silvia Barus
Original assignee: Indesit Co SpA
Current assignee: Whirlpool EMEA SpA
Priority date: 2012-12-28
Filing date: 2013-12-27
Publication date: 2014-07-03
Anticipated expiration: 2015-06-28
Also published as: ITPR20120094A1

Abstract

A dishwashing machine washing cycle (1) which comprises a cold pre washing step, a hot washing step and a hot rinse step that immediately follows the hot wash step.

Description

DESCRIPTION

DISHWASHER MACHINE AND WASHING CYCLE

Technocal field

The present invention refers to a dishwashing machine and its washing cycle.

State of the art

The known dishwasher machines perform on the crockery a cleaning action consisting in mechanical, chemical and thermal operations performed jointly or separately.

The mechanical action is obtained with washing liquid jets that hit the crockery, the chemical action is due to detergents and washing additives and the thermal action is based on different temperatures reached by the washing liquid.

The above actions are appropriately combined in so-called programs or washing cycles and all modern dishwashing machines comprise a programming device that controls the above programs or washing cycle, and through which the user can select the desired cycle among others. Generally, all the dishwashers include a so-called economic or eco wash program, normally chosen to wash crockery lightly dirty or with easy removable dirty or when there's only a partial load of the dishwasher itself or when the load consists only of plates and glasses without pots.

The economic washing program, usually, comprises a cold pre-washing step, which is performed with not heated washing liquid, a hot washing step which is done with heated washing liquid, a cold rinse step finally followed by a hot rinse step.

As it is known, the washing liquid, for steps that require a hot washing liquid, is heated in a lower washtub usually provided in the dishwasher. The known economic cycles, like the above, have a drawback due to the cold rinse step between the hot washing and the hot rinse step.

In fact to achieve this step the washtub, heated from the hot wash, cools for the cold rinse step and must be then re-heated for the hot rinse step. The cycle comprising the interposition of a rinsing cold step between the hot washing step and hot rinse step comes to be expensive in energy terms because the cold rinse step produces to the washtub a high heat loss and in this way a low energy a overall efficiency of the machine relatively low.

In this context, the technical object of the present invention is to propose a dishwasher machine and an economic washing cycle free from the above drawbacks.

Aim of the invention

The purpose of the present invention is to propose a dishwashing machine provided with an economic washing cycle less wasteful in terms of energy than the other known solutions.

The technical object and the specified aims are substantially achieved by a dishwashing machine and a respective washing cycle according to the claim 1 .

Brief description of the drawings

Further characteristics and advantages of this invention will seem more clear from the indicative and therefore non-limiting description of a preferred but not exclusive embodiment of a washing machine and a related washing cycle as schematized in the attached figure .

Detailed description of preferred embodiments of the invention

Referring to the attached figure, it is observed an example of a time- temperature diagram relating to a program or washing cycle 1 according to the present invention (the temperature trend is expressed in qualitative form).

The cycle 1 is programmed to be executed in a dishwashing machine, or simply dishwasher, of a type substantially known not here illustrated, and described only for the essential parts to understanding of the present invention.

As it is known, for its operation the dishwasher is connected to a water supply from which it receives water that is , substantially , a washing liquid to which are optionally added washing agents .

The dishwashing machine comprises, in summary, a washtub, the rotating sprayer , an operatively active pump between the washtub and the rotating sprayer, a filtering system in the washtub, a heater of the washing liquid. The washing liquid heater is used to heat the washing liquid in the washtub.

The dishwasher comprises a programming device configured for the selection and control of at least of the wash cycle 1 which is advantageously stored in programming device.

The washing cycle 1 comprises a cold pre-washing step PF, a washing step L and a hot rinse step RC. Preferably the washing step comprises a hot washing step LC . In the particular exemplified embodiment in the figure, the step washing L comprises a cold wash (with water at room temperature) step LF1 . The cold wash step LF1 precedes said hot washing step LC.

According to the present invention, hot rinse step RC immediately follows said hot washing step LC.

In this way the washtub does not waste too much heat between RC step and LC step, more specifically, as will be better explained below, the hot rinse step RC and the hot washing step LC are only separated by a unloading step and a loading step of the washing liquid used for rinse, during which, suitably, the washtub practically does not cool down or however it does it in a limited way.

Conveniently, with cold pre-washing step PF is meant a step in which the washing liquid is not heated through an electrical resistance of the dishwasher. Conveniently with hot washing step LC is meant a step in which the washing liquid is heated with said resistance (similar thing can be repeated for the hot rinse RC).

Preferably, the cold pre-washing step PF has a duration comprised between 10 and 30 minutes.

Preferably, the hot washing step LC has a duration comprised between 50 and 100 minutes.

Preferably, the hot rinse step RC has a duration comprised between 10 and 30 minutes.

In a preferred embodiment, in the washing cycle 1 , hot washing step LC comprises a heating step R1 of the washing liquid to a temperature comprised between 45°centigrade and 55°centigrade .

Preferably, in fact, the hot washing step LC takes place at least, partly with the washing liquid at a temperature comprised between 45 ° centigrade and 55 "centigrade.

In a preferred embodiment, the hot rinse step RC comprises a heating step R2 of washing liquid to a temperature comprised between 45 ¾entigrade and 65 ¾entigrade.

The hot rinse step RC takes place at least partly, with the washing liquid at a temperature comprised between 45¾entigrade and 6 5° centigrade.

In the illustrative embodiment in the example, it is observed that the wash cycle 1 comprises a first loading step C1 of a first washing liquid. In a known way, during step C1 the washing liquid, for example water from supply network, is fed into the washtub.

After the loading step C1 , the cold pre-washing step PF provides for a first cold pre- washing step PF1 with the first washing liquid.

At the end of the first pre-washing step PF1 , the cycle 1 comprises a unloading step S1 of the first washing liquid immediately followed by a loading step C2 of a second washing liquid that last for example, overall 2 minutes.

It's important to note that the second washing liquid is water that can be loaded either from the water supply or the first washing liquid suitably filtered .

Once loaded the second washing liquid , the washing step L comprises a washing step LF1 with the second washing liquid at room temperature. The washing step LF1 has a duration comprises 5 and 10 minutes.

The cold washing step LF1 with the second washing liquid lasts preferably 5 minutes.

After the cold washing step LF1 , begins the heating step R1 of washing liquid preferably up to a temperature of 53°centig rade.

According to in the example illustrated, the heating step R1 lasts about 15 minutes.

The hot washing step LC comprises a washing step LC1 with the washing liquid to the temperature reached at the end of the heating step R1 ( step LC1 is, therefore, a hot maintenance step).

The hot washing step LC lasts preferably further 60 minutes after the heating step R1 during which the temperature of the washing liquid is maintained at about 53¾entigrade.

In other words the washing step LC1 lasts, in the illustrated example, 60 minutes.

It's important to note that at the start of the heating step R1 , a detergent DET or first washing agent, is added to the washing liquid.

At the end of hot washing step LC, the cycle 1 comprises an unloading step S2 of the second washing liquid and a loading step C3 of a third washing liquid before the said hot rinse step RC.

Such liquids are generally always water from the network.

The unloading step S2 of the second washing liquid and the loading step

C3 of the third washing liquid last for a total of about 5 minutes.

Once loaded the third washing liquid, begins the said hot rinse step RC which comprises the heating step R2.

The heating step R2 lasts for example 13 minutes, and brings, preferably, the washing liquid temperature to about 55 °C.

The hot rinse step RC lasts further, for example , half a minute , during which the temperature is maintained at about 55 °C .

In practice, the hot rinse step RC comprises a hot rinse step RC1 that follows the heating step R2 that lasts, in the illustrated example, half a minute.

At the end of hot rinse step RC, the cycle 1 comprises a unloading step S3 not described in detail.

The cycle 1 comprises a step of adding of a second washing agent, for example, rinsing aid, during hot rinse step RC.

In the illustrated example the sparkling aid is introduced in the cycle 1 during the heating step R2 (typically to the achievement of a predetermined temperature or after a predetermined time from the start of the heating step R2 ).

It important to observe that all loading and unloading steps of the washing liquids take place in a substantially known way and therefore are not described in detail.

The washing liquid used in the washtub for the washing cycle 1 is present in one amount comprised between 2.5 liters and 4.5 liters.

The washing program described allows a significant power savings compared to the known economic cycles.

The elimination of the cold rinse step between the hot washing step and the hot rinse step, contributes to the maintenance of the temperature in the washtub that is not cooled, and therefore should not be further heated.

Claims

1 .Washing cycle for a dishwasher machine, said washing cycle comprising a cold pre-washing step (PF), a hot washing step (LC) and a hot rinse step (RC), said washing cycle being characterized in that said hot rinse step (RC) immediately follows said hot washing step (LC).

2. Washing cycle according to claim 1 wherein said cold pre-washing step (PF) has a duration comprised between 10 and 30 minutes.

3. Washing cycle according to claim 1 or 2, wherein said hot washing step (LC) has a duration comprised between 50 and 100 minutes.

4.Washing cycle according to any one of claims 1 to 3, wherein said hot rinse step (RC) has a duration comprised between 10 and 30 minutes.

5. Washing cycle according to any one of claims 1 to 4, wherein said hot washing step (LC) comprises heating step (R1 ) of a washing liquid to a temperature comprised between 45° centigrade and 55 " centigrade, said hot washing step (LC) taking place at least partly with the washing liquid at a temperature comprised between 45°centigrade and 55° centigrade.

6. Washing cycle according to any one of claims 1 to 5, wherein said hot rinse step (RC) comprises a heating step (R2) of a washing liquid to a temperature comprised between 45°centigrade and 65 "centigrade, said hot rinse step (RC) taking place at least partly with the washing liquid at a temperature comprised between 45°centigrade and 65 "centigrade.

7. Washing cycle according to any one of claims 1 to 6, comprising a first loading step (C1 ) of a first washing liquid, an unloading step (S1 ) of said first washing liquid, a loading step (C2) of a second washing liquid, an unloading step (S2) of said second washing liquid, a loading step (C3) of a third washing liquid, said cold pre-washing step (PF) comprising a first prewashing

step (PF1 ) with said first washing liquid, said hot washing step (LC) taking place with said second washing liquid and comprising a heating step (R1 ) of said second washing liquid, said hot rinse step (RC) taking place with said third washing liquid and comprising a heating step (R2) of said third washing liquid.

8. Washing cycle according to claim 7, wherein the first pre-washing step (PF1 ) lasts 20 minutes, the hot washing step (LC) lasts for an interval comprised between 70 and 90 minutes and the hot rinse step (RC) lasts from 10 to 15 minutes.

9. Washing cycle according to claim 7 or 8, wherein said 5 second washing liquid is heated to 53°centigrade and said third w ashing liquid is heated to 55°centigrade.

10. Washing cycle according to any one of claims 7 to 9 comprising a step of adding a first washing agent (DET) during the hot washing step (LC), preferably with the second washing liquid at room temperature, and a step of adding a second washing agent during the hot rinse step (RC).

1 1 .Dishwasher machine comprising a programming device configured for the selection and control of at least one washing program stored in said programming device, said dishwasher machine being characterized in that said washing program is according to any one of claims 1 to 10.