EP2568075A1

EP2568075A1 - Drying or washing/drying machine comprising means for treating laundry items by using vaporized condensed water

Info

Publication number: EP2568075A1
Application number: EP12183411A
Authority: EP
Inventors: Giuseppina Pia Potena; Nicola Colucci; Aldo Liberatore; Gioavanni Bombardieri
Original assignee: Indesit Co SpA
Current assignee: Whirlpool EMEA SpA
Priority date: 2011-09-12
Filing date: 2012-09-07
Publication date: 2013-03-13

Abstract

A drying or washing/drying machine (1) for treating laundry items (2), comprising a tub, inside of which a rotary drum (3) is positioned, and steam treatment means for sanitizing and stretching the fibers of the laundry items (2), wherein the steam treatment means vaporize condensed water.

Description

The present invention relates to a drying or washing/drying machine comprising means for subjecting laundry items to a steam treatment.
As is known, a steam treatment allows disinfecting laundry items by reducing the bacterial charge thereof. In addition, during the drying cycle such a treatment allows stretching the fabrics, which would otherwise turn out wrinkled at the end of the process.
This type of treatment is widely used at industrial level, but its use in a household environment requires taking into account the fact that maintenance will have to be carried out by users paying less attention and having lower technical skills, and that the machine of the present invention must be offered at an affordable price.
Aiming at reducing the cost of a machine comprising steam treatment means, document WO 2010/114332 A2 by LG ELECTRONICS INC., describes a solution (shown in Fig. 1 of the present application) which allows integrating into a single heater both a heater for heating a drying air flow and a steam generator for treating laundry items.
A well-known problem of a steam generator like the one described in the above-mentioned patent application is the formation of calcareous deposits in the coil duct 330 when non-demineralized water is vaporized therein.
The present invention aims at solving these and other problems by providing a drying or washing/drying machine comprising means for steam treatment of laundry items.
Furthermore, the present invention aims at solving these and other problems by providing a method for drying laundry items which comprises at least one steam treatment step wherein vaporized condensed water is used.
The idea at the basis of the present invention is to generate steam by using condensed water coming from the laundry drying process, so as to prevent the drying or washing/ drying machine from having to use water from the mains.
In fact, the water coming from the mains normally contains a more or less large quantity of limestone, which will deposit onto the walls of the coil duct during the water vaporization process, thus impairing and/or preventing the operation of said coil duct.
Further advantageous features of the present invention will be set out in the appended claims.
These features as well as further advantages of the present invention will become more apparent from the following description of an embodiment thereof as shown in the annexed figures, which are supplied by way of non-limiting example, wherein:

Fig. 1 is a perspective view of the heater described in document WO 2010/114332 A2 by LG ELECTRONICS INC.;
Fig. 2 shows a diagram of the machine according to the invention, which comprises a condensation and vaporization circuit;
Fig. 2b shows a first variant of the diagram of Fig. 2, which also includes a bottle for collecting condensed water;
Fig. 2c shows a second variant of the diagram of Fig.2, which includes a nozzle for nebulizing condensed water;
Fig. 2d shows a third variant of the diagram of Fig.2, which includes both the bottle of the first variant of Fig. 2b and the nozzle of the second variant of Fig. 2c;
Fig. 3 shows a detail of the diagram of Fig. 2, concerning the condensation circuit;
Fig. 4 is a perspective top view of a cross-flow thermal exchanger comprised in the machine of Fig. 2.

With reference to Fig. 2, there is shown a drying or washing/drying machine 1 that comprises drying means, steam treatment means for treating laundry items 2, and a tub (not shown in the figures), inside of which a rotary drum 3 is positioned, into which drum laundry items 2 can be placed for subjecting them to a drying process; said tub comprises an front access door 4, through which laundry items 2 can be loaded into or unloaded from the drum 3, an inlet 5 for a drying flow of dry hot air 51, an inlet for steam 6, arranged at the rear of the tub, and an outlet 7 for a flow of humid hot air 71.
The drying means comprise a heater 8, preferably arranged near the back of the tub, which comprises heating means, preferably of the electric type, capable of both increasing the temperature of a dry cold air flow 52 and vaporizing a water flow; said heater 8 further comprises a cold air inlet 81, a hot air outlet 82, a water inlet 83 and a steam outlet 84.
Through the inlet 81, the heater 8 receives the dry cold air flow 52, which, by lapping heating means, preferably consisting of electric resistors, produces the drying flow of dry hot air 51, which in turn flows out through the hot air outlet 82; said hot air duct 82 is put in fluidic communication with the tub of the drying or washing/ drying machine by means of the inlet 5.
The cold air inlet 81 may be put in fluidic communication with the outside environment or, more preferably, with condensing means. In this latter case, also the outlet 7 will have to be put in fluidic communication with said condensing means, as opposed to the outside environment, thus advantageously preventing the moisture from being dispersed in the surrounding environment. This aspect is important when the machine is to be installed in a house, in that this avoids adversely affecting the comfort of the surrounding environment.
With reference also to Figs. 3 and 4, the condensing means comprise a thermal exchanger 9, preferably of the cross-flow type, and a tank 10 for collecting condensed water generated by condensation of moisture present in the flow of humid hot air 71.
The thermal exchanger 9 comprises a humid hot air inlet 91 for the air flow 71, a dry cold air outlet 92 for the air flow 52, a cold cooling air inlet 93 for a cooling air flow 96, a condensate drain 94, through which a condensed water flow 98 is collected, and a hot air outlet 95 for a heated air flow 97.
The humid hot air inlet 91 is in fluidic communication with the tub outlet 7 through an extraction duct (not shown in the figures), whereas the dry cold air outlet 92 is in fluidic communication with the tub inlet 5 through an intake duct (not shown in the figures).
Along the extraction duct a fan 12 is installed, which speeds up the circulation of the air flows in the extraction and intake ducts.
Also along the extraction duct, preferably upstream of the fan 12, one may advantageously install an anti-lint filter 11 for trapping any lint produced by the laundry items 2 during the drying treatment.
The cold cooling air inlet 93 and the hot air outlet 95 are both in fluidic communication with the outside environment and, for the purpose of advantageously increasing the efficiency of the thermal exchanger 9, the velocity of the cooling air flow 96 may advantageously be increased by using an external fan 13.
The condensate drain 94 is in fluidic communication with the tank 10 through a condensate duct (not shown in the figures), by means of which the condensed water flow 98 arrives at and is collected in the tank 10. The tank 10 comprises an outlet 101 in fluidic communication with the steam treatment means; said tank 10 is advantageously positioned near the thermal exchanger 9, preferably under it, so as to make the condensate easier to collect by gravity.
The steam treatment means comprise the heater 8 and a pump 14, the latter comprising an intake duct and a delivery duct. The outlet 101 of the tank 10 is put in fluidic communication with the intake duct of the pump 14 by means of a condensed water duct (not shown in the figures), and the delivery duct 14 is in fluidic communication with the water inlet 83 of the heater 8.
By using condensed water by means of the tank 10, said tank 10 needs not be filled before every drying cycle, and therefore it can advantageously be placed in the rear part of the drying or washing/drying machine, near the heater 8. In this configuration, due to the dispersed heat irradiated by the heater 8, the temperature of the water contained in the tank 10 is advantageously higher than ambient temperature.
When the steam treatment means are in operation, the action of the heater 8 vaporizes the water flow, thus transforming it into a steam flow, which exits through the steam outlet 84.
It must be pointed out that the heater 8 keeps the water/steam and air flows separate by using a water vaporization duct (not shown in the figures); said vaporization duct contacts the heating means of the heater, thereby advantageously heating the condensed water, which, since it substantially contains no dissolved limestone, will leave no calcareous deposits onto the inner surface of said vaporization duct.
Also, this configuration of the heater 8 allows the drying means and the steam treatment means to operate independently of each other, thus making it possible to provide specific drying and sanitizing cycles for laundry items 2 of different types.
A first variant is shown in Fig. 2b, wherein the above-described drying or washing/drying machine 1 further comprises a transfer pump 16 positioned downstream of the tank 10; said transfer pump 16 can transfer the condensed water, whether simultaneously or alternately, into a reservoir 17 and/or a bottle 18.
The reservoir 17 is in fluidic communication with the intake duct of the pump 14, thus acting as a storage unit and advantageously preventing any air from entering the pump 14. This will increase the operating life of the pump 14.
Finally, the bottle 18 collects the condensed water during and/or at the end of the process of drying the laundry items 2, and said bottle 18 may advantageously be separated from the machine 1 for being emptied, thus making it unnecessary to connect the machine 1 to a drain mains.
A second variant is shown in Fig. 2c, wherein the steam treatment means comprise nebulization/atomization means, which in turn comprise e nebulization nozzle 15 and a pump 14 comprising an intake duct, a delivery duct and an air/water mixer, if mist is to be generated by atomization of water molecules.
Just like the main embodiment, the outlet 101 of the tank 10 is put in fluidic communication with the intake duct of the pump 14 by means of the condensed water duct (not shown in the figures), whereas the delivery side, unlike the main embodiment, is put in fluidic communication with the nebulization nozzle 15 by means of a high-pressure duct (not shown in the figures), since the pressures involved may be in the range of 50 bar to 200 bar, preferably 100 bar to 150 bar. The combined action of the pump 14 and nozzle 15 allows to nebulize/atomize the water into droplets forming a flow of nebulized water or mist.
The end portion of the nozzle 15 is put in fluidic communication with the atomized/nebulized water inlet 6 of the tub through a water/mist duct (not shown in the figures).
When the steam treatment means are in operation, the flow of nebulized water or mist is delivered into the tub and then vaporized by the high air temperature caused by the drying flow of dry hot air.
Finally, a third variant is shown in Fig. 2d, wherein the machine 1 additionally comprises, compared to the above-described variant, the transfer pump 16, the reservoir 17 and the bottle 18 (like those of the first variant), wherein the transfer pump 16 can transfer the condensed water, whether simultaneously or alternately, into the reservoir 17 and/or the bottle 18. This combines the advantages obtainable from the first variant with those of the second variant.
In conclusion, the machine 1 can treat laundry items 2 in accordance with a drying method that comprises a steam treatment step A and a drying step B, wherein the steam treatment step A uses vaporized condensed water to sanitize and stretch the fibers of the laundry items 2, and wherein the condensed water is generated during the drying step B; said step A is carried out before, during or after the drying step B.
Of course, the example described herein may be subject to further variations, which will nonetheless still fall within the scope of the following claims.

Claims

A drying or washing/drying machine (1) for treating laundry items (2), comprising a tub, inside of which a rotary drum (3) is positioned, and steam treatment means for sanitizing and stretching the fibers of the laundry items (2),
characterized in that
the steam treatment means vaporize condensed water.
A machine (1) according to claim 1, wherein the steam treatment means comprise a heater (8) and a pump (14) that comprises an intake duct and a delivery duct, wherein the condensed water flows through the intake duct, and the delivery duct is in fluidic communication with the heater (8).
A machine (1) according to claim 2, further comprising condensing means which in turn comprise an outlet for dry cold air (92) and an inlet for humid hot air (91), wherein the latter are placed in fluidic communication with the heater (8) and with the tub, respectively, so as to condense excess moisture contained in a humid hot air flow (71) coming from said tub following a laundry drying process.
A machine (1) according to claim 3, wherein the condensing means comprise a thermal exchanger (9) and a tank (10) for collecting a condensed water flow (98) caused by condensation of the excess moisture contained in the humid hot air flow (71).
A machine (1) according to claim 4, wherein the condensing means further comprise a transfer pump (16) positioned downstream of the tank (10), and wherein said transfer pump (16) can transfer the condensed water, whether simultaneously or alternately, into a reservoir (17) and/or a bottle (18).
A machine (1) according to claim 5, wherein the bottle (18) can advantageously be separated from the machine (1) for being emptied, thus making it unnecessary to connect the machine (1) to a drain mains.
A machine (1) according to any one of claims 4 to 6, wherein the thermal exchanger (9) is of the cross-flow type.
A machine (1) according to claim 7, wherein the thermal exchanger (9) comprises the humid hot air inlet (91), the dry cold air outlet (92), an inlet for cold cooling air (93), a drain for condensed water (94) and an outlet for hot air (95), respectively for the humid hot air flow (71), the dry cold air flow (52), a cooling air flow (96), the condensed water flow (98) and a heated air flow (97).
A machine (1) according to claim 8, wherein the velocity of the cooling air flow (96) can advantageously be increased by using an external fan (13).
A machine (1) according to any one of claims 4 to 9, wherein the water flow entering the vaporization means comes from the tank (10) positioned near the thermal exchanger (9).
A machine (1) according to any one of claims 5 to 9, wherein the water flow entering the vaporization means comes from the reservoir (17), which, by acting as a storage unit, advantageously prevents any air from entering the pump (14).
A method for drying laundry items (2), comprising a steam treatment step (A) and a drying step (B),
characterized in that
said steam treatment step (A) utilizes vaporized condensed water to sanitize and stretch the fibers of the laundry items (2), and wherein said condensed water is generated during the drying step (B).
A method according to claim 12, wherein the steam treatment step (A) is carried out before, during or after said drying step (B).
A machine according to any one of claims 1 to 11, further comprising a heater (8), and wherein the steam treatment means also comprise nebulization/atomization means that nebulize/atomize condensed water, which is then vaporized inside the tub by means of the heat generated by the heater (8).
A method for drying laundry items (2), comprising a steam treatment step (A) and a drying step (B),
characterized in that
said steam treatment step (A) utilizes condensed water which is nebulized/atomized and subsequently vaporized to sanitize and stretch the fibers of the laundry items (2), and wherein said condensed water is generated during the drying step (B).