WO2015083061A1

WO2015083061A1 - Household washing and drying appliance

Info

Publication number: WO2015083061A1
Application number: PCT/IB2014/066477
Authority: WO
Inventors: Mauro MANCINI
Original assignee: Indesit Company S.P.A.
Priority date: 2013-12-05
Filing date: 2014-12-01
Publication date: 2015-06-11
Also published as: EP3077587A1; ITTO20130999A1; EP3077587B1

Abstract

The invention relates to a washing/drying machine, wherein washing water circulation is controlled by a pair of valves (20, 21 ) that distribute the flow into either or both branches (22, 23) of a distribution circuit. The washing/drying machine provides energy savings because the drying air condenser (14) can be cleaned by using wash or rinse water during the operating steps of the washing/drying machine.

Description

HOUSEHOLD WASHING AND DRYING APPLIANCE

DESCRIPTION

The present invention relates to a household appliance for washing and drying laundry or other items in general.

It is worth pointing out beforehand that in this description and in the appended claims reference will prevalently be made, unless otherwise specified, to machines for washing and drying laundry.

However, the following description will also be compatible with and applicable to other household appliances wherein washing and drying cycles are carried out, e.g. dishwashers.

Machines for washing and drying laundry, also called washing/drying machines, are washing machines that can dry the load at the end of the wash cycle.

For this purpose, they are equipped with a drying air circulation circuit, wherein heated air is made to lap the humid laundry in the drum of the machine, thereby drying it.

In particular, since the air that laps the laundry is enriched with steam, in order to increase the efficiency of the drying cycle it is known to reduce the humidity degree thereof by condensing, at least partly, the steam.

Indeed, further being unable to dry the laundry, the air saturated with aqueous vapour is also a cause of efficiency losses in the ventilation system and in the heating system, which typically includes electric resistors.

In order to dehumidify air in washing/drying machines, different solutions are known which generally utilize cold water to remove heat from drying air, so as to condense the steam contained therein.

For example, one possible solution is to draw off some water from the washing circuit and introduce it in countercurrent against the air flow, so that the steam present in the latter will coalesce with the cold water and can be removed along with it, to be then drained through the tub bottom. This solution is described in European patent application EP 1 577 433 published in 2005 by LG Electronics .

In a different solution known in the art, instead, the air is dehumidified as it flows through a heat exchanger, where it is cooled: the steam condenses in the exchanger, and the condensed water is collected and drained.

Air cooling is obtained in the exchanger by causing the air to exchange heat with water coming from the washing circuit of the washing/drying machine; the exchanger may be of the plate type, of the finned battery type, or of any other type suitable for air-water thermal exchange.

Controlling the water coming from the washing circuit in order to dehumidify the air as explained above requires the presence of further valves and ducts adding up to those that are strictly necessary for a simple washing machine, inevitably leading to a more complex washing/drying machine.

In particular, it is necessary to distribute the water coming from the main into the washing circuit and into the air dehumidification circuit, regardless of whether the latter is of the type wherein water is directly supplied into the air path or into a condenser.

Furthermore, the water is often used also for other functions such as, for example, cleaning filters or the dehumidification condenser; it can thus be easily understood that it is important, in machines for washing and drying laundry or the like, to reduce the number of water valves and/or ducts required for such functions.

Therefore, the technical problem underlying the present invention is to provide a household appliance for washing and drying a load in general, having such structural and operating characteristics as to allow a simpler management of the washing water, for carrying out a plurality of functions.

The principle for solving this problem is to exploit the same components for multiple functions, so that their number can be reduced without affecting the machine' s performances . In accordance with a preferred embodiment, the household appliance is a washing/drying machine comprising a condenser for dehumidifying the load drying air.

The features of the invention and the effects thereof will become more apparent in view of the following description of an example of embodiment of the invention, as shown in the drawings annexed hereto by way of non-limiting example, wherein:

Figure 1 shows an axonometric view of a tub of a washing/drying machine according to the invention;

- Figure 2 shows an axonometric view, from an angle opposite to that of Fig. 1 , of the tub of a washing/drying machine according to the invention;

Figure 3 shows a detail of the tub of the washing/drying machine illustrated in the preceding figures;

- Figure 4 shows another detail of the washing/drying machine according to the invention;

Figure 5 is a side view of the detail of Fig. 4;

Figure 6 is a diagram that shows the water circuit of the washing/drying machine shown in the preceding figures;

- Figure 7 is a diagram relating to a variant of the washing/drying machine of Fig. 6.

With reference to the above-listed drawings, reference numeral 1 designates as a whole a tub of a washing/drying machine in accordance with the invention.

For easy understanding, the drawings show the tub 1 without the external cabinet of the washing/drying machine; it is nevertheless apparent that, in the complete version of the household appliance, said tub 1 is inserted into a cabinet or housing structure, in a per se known manner.

The tub 1 is of the horizontal-axis type and has a front opening 2 for loading laundry into a rotary drum in the tub' s inner cylindrical chamber.

To this end, the washing/drying machine comprises a motor 6 for rotating the drum, to which it is connected by means of a drive belt 7; of course, any other solution suitable for driving the drum could be used for the purposes of the invention.

The drying air circuit comprises an air delivery channel 1 0 extending from a base 1 1 that houses an impeller (not shown in the drawings and per se known) to a mouth 1 2 for supplying the air into the inner chamber of the tub 1 .

The air circulation circuit further comprises an intake channel 13 upstream of the impeller, which channel is arranged in the rear portion of the tub and extends from the condenser 14 to the base 1 1 that houses the impeller.

In the washing/drying machine 1 , the washing water distribution circuit comprises two valves 20, 21 that control the main functions thereof.

In particular, the valves 20 and 21 are electrically controlled by the control system of the household appliance, and are connected upstream to the water supply network where the washing/drying 1 is installed, which is not shown in the drawings because it is per se known, since it is the typical water main commonly found in civil buildings.

Downstream, the electrovalves 20, 2 1 are connected to the water distribution circuit in the washing/drying machine, which comprises two branches 22, 23 : the first branch is used for the laundry washing cycle, while the second one is used for the laundry drying cycle.

For this purpose, along the branch 22 there is a tank 26 for washing agents, a tube 28 exiting therefrom for introducing the water into the washing tub 1 .

The second water distribution branch 23 is used for conveying the water to the condenser 14, where the drying air is dehumidified.

To this end, the water distributed by the electrovalves 20, 2 1 flows into a fiting 29 formed in a tube bundle 30 that, in accordance with a preferred embodiment of the invention, consists of a moulded piece preferably made from plastic material, arranged next to the washing tub 1 . The water that flows into the tube bundle 30 is delivered to the condenser 14 to cool the air circulating in the drying circuit, or is used for cleaning the exchanger during the washing step.

Indeed, it is periodically necessary to remove lint, fibers and residues in general that are inevitably dragged by the drying air flow and deposited on the exchanger 14, which in the long run may adversely affect the thermal exchange and reduce the efficiency of the machine' s drying cycle.

Such cleaning is carried out by delivering washing water through the exchanger 14, where air to be dehumidified normally flows.

Preferably, the exchanger 14 is washed by means of water flowing in countercurrent against the air flow, which water is then drained, possibly after having been treated in a filter 32 for removing fibers and lint.

The same applies to the water that flows into the exchanger, which, after having cooled the drying air, is then delivered to the drain.

Advantageously, in order to be able to perform these functions and direct the water into the two branches 22 , 23 of the system, downstream of the tub 1 the water is sent to a diverter 34, which conveys the flow supplied by the pump 33 either towards said branches or towards the drain. The diverter preferably consists of a valve with three or more ways, even though any other solution suitable for this purpose can be employed.

It must however be pointed out that the presence of the diverter 34 is not strictly necessary, although it is advantageous for recirculating the water into the two branches 22, 23 of the distribution circuit from the washing tub, because it may not be included should recirculation not be provided.

This i s the case of the variant of Figure 7, which shows a diagram of a household appliance as described heretofore, wherein the water, downstream of the washing tub 1 , is drained by the pump 33 instead of being recirculated into the two branches 22, 23 of the circuit as specified for the other solution (Fig. 6). The washing/drying machine according to the invention operates as follows .

When the washing cycle starts and water is taken in from the household water main, the two valves direct the whole flow towards the detergent tank 26, from which the water flows into the duct 28 to reach the washing chamber 1 .

The washing cycle comprises the usual operating steps of washing/drying machines, i .e. prewash, one or more wash steps followed by respective rinse steps, spin and, finally, drying.

During the operating steps, the valves 20, 2 1 deliver the water towards the washing branch 22 and/or towards the drying branch 23 of the distribution circuit; in fact, one characteristic of such valves is that they can partialize the water flow and distribute it into the circuit branches with variable flow rates, according to the different steps of the operating cycle.

In accordance with a preferred mode of operation of the washing/drying machine, the rinse water is reused, at least partly, for cleaning the exchanger 14.

In fact, instead of being drained, the rinse water contained in the washing tub 1 can be recirculated by the pump 33 towards the electrovalve 21 , from where it can be used for washing the condenser 14.

This reduces the consumption of water, since rinse water is used for a secondary function such as the cleaning of the condenser 14, which water would otherwise be evacuated.

Furthermore, it must be pointed out that the cleaning operation is carried out during the normal operating cycle of the washing/drying machine, without affecting the cycle duration.

This is also advantageous in terms of energy consumption during the normal laundry washing cycle, since the total cycle time is not modified by the step of washing the exchanger 14.

Of course, other variants of the invention may also be conceived, which will nonetheless still fall within the scope of the following claims.

Claims

1 . Household appliance for washing and drying a load, comprising a washing tub ( 1 ) into which the load to be washed is placed, a water distribution circuit for distributing water to/from the washing tub, which comprises a condenser ( 14) for the drying air, characterized in that the water distribution circuit comprises at least one pair of branches (22, 23 ), wherein distribution occurs into such branches by means of a pair of valves (20, 2 1 ),

2. Household appliance according to claim 1 , wherein the pair of valves (20, 21 ) is connected upstream to the water main.

3. Household appliance according to claim 1 or 2, wherein a first branch (22) of the water distribution circuit comprises a tank (26) for detergents and a duct (28) for the connection to the washing chamber ( 1 ).

4. Household appliance according to any one of the preceding claims, wherein a second branch (23 ) of the water distribution circuit is connected to the condenser ( 14) and comprises at least one portion of the drying air outflow channel ( 1 3) .

5. Household appliance according to any one of the preceding claims, comprising a pump (33) arranged downstream of the tub ( 1 ) for recirculating water exiting therefrom, and in fluid communication with the condenser ( 14) for delivering rinse water thereto.

6. Household appliance according to any one of the preceding claims, wherein a part of the second branch (23) of the circuit is implemented in a tube bundle (30) .

7. Household appliance according to any one of the preceding claims, wherein the water distribution circuit downstream of the washing tub ( 1 ) includes a diverter (34) for directing the water either towards said pair of valves (20, 21 ) or towards the drain.