Laundry dryers generally comprise a casing that houses a laundry container, like a rotating drum, where laundry to be treated is received, and an air circuit for carrying out drying operation by circulating hot air through the laundry container. In a heat pump laundry dryer, drying air coming out from the laundry container is first dehumidified through a first heat exchanging portion (a refrigerant fluid evaporating unit) of a heat pump circuit, and then heated through a second heat exchanging portion (a refrigerant fluid condensing unit) of the same heat pump circuit thereby achieving a considerable energy saving compared to condenser type laundry dryer. In the latter type of laundry dryer, condensing means in the form of an air-air heat exchanger are provided in the drying air circuit for removing moisture from laundry drying air while heat is generated by an electric resistance placed within the drying air circuit.
Both in heat pump and in condenser dryers moisture removed from drying air is collected within a reservoir located in the cabinet bottom part and then pumped up to a removable container placed on a front upper portion of the cabinet by pumping means. Since condensed moisture is drained from drying air circuit, in prior art dryers such air may be drained together with moisture and being sucked into said pumping means thereby causing damages and/or a malfunction of the draining system.
In addition, even when filtered, drying air may comprise fluff particles that can cause pump clogging in case an amount of drying air mixes with condensed moisture. Fluff accumulated on those parts of drying air circuit just downstream the main air filter, which is generally provided in proximity of an air outlet port in the laundry container, may be flushed away by moisture contained in drying air when the latter passes through cold surfaced. This problem may arise especially after a relatively large number of cycles or when drying air filters and/or condensing devices are not periodically cleaned.
Furthermore, prior art laundry dryers generally provides draining arrangements in correspondence of elements, such as an evaporator in a heat pump type dryer or a condenser in a condenser type dryer, where moisture is effectively condensed but such dryers have no provision for collecting condensate in other regions of the drying air circuit where temperature may be favorable to moisture condensation. In a laundry dryer of heat pump type, one of the above said regions has been found to be the heat exchanger (a refrigerant fluid condensing unit) provided for heating the drying air flow. This is due to the fact that, in a heat pump type dryer, the position of the condensing unit is quite near to that of the cold surfaces of the evaporating unit and therefore moisture can be further condensed on a region of the condensing unit adjacent to the evaporating unit. Presence of condensate on a heat pump circuit condenser is particularly undesired because the condensing unit yield drops dramatically.
In a heat pump type dryer, a further potential moisture condensing surface may be the region in front of the evaporating unit, i.e. a region upstream such unit considering the flow direction of laundry drying air, because the drying air enters that region with the highest amount of humidity with respect to the whole drying air circuit. Since that region may feel the evaporator low temperature, a moisture condensation becomes highly probable. In addition, in said region facing the evaporator unit, drying air flow changes its direction from a substantially vertical plane to a substantially horizontal plane. This causes air to contact drying air conduit walls thereby increasing possibility for a moisture condensation on such walls. A moisture condensation in that region may disadvantageously cause undesired and uncontrolled water shedding.
The aim of the present invention is therefore to solve the noted drawbacks and thus providing a laundry dryer having an improved condensed water draining circuit.
An object of the present invention is to provide a laundry dryer having an improved performance in draining moisture condensed from a drying air flow.
A further object of the invention is to provide a laundry dryer having an improved reliability compared to prior art dryers.
Another object of the invention is to provide a laundry dryer avoiding the risk that moisture, which incidentally condenses on regions of a drying air circuit where temperature is favourable to such condensation can decrease performance of operational components.
Yet another object of the present invention is to provide a laundry dryer wherein maintenance intervention operated by specialized technicians are simplified compare to known dryers.
Advantages, objects, and features of the invention will be set forth in part in the description and drawings which follow and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be reached and attained by a laundry dryer comprising a casing accommodating therein a drying air circuit, a laundry container, a drying air moisture removing unit and further operational devices for carrying out a drying treatment on said laundry, said dryer further comprising a basement having a condensate draining path for conveying moisture condensed from drying air towards a reservoir wherein at least a portion of said condensate draining path extends on a basement region where drying air exiting the laundry container flows before entering said drying air moisture removing unit. Preferably, the condensate draining path comprises at least one condensate retaining region so as to form a liquid trap for preventing drying air from dispersing along path. Preferably, at least one condensate retaining region comprises a siphon-shaped surface. Preferably, the condensate draining path extends from a front to a rear side thereof, at least partly on an edge region of the basement. Preferably, at least a portion of the condensate draining path extends onto the basement along a direction which is substantially parallel to a drying air flow direction. Preferably, the reservoir is arranged in proximity of a first cabinet rear wall which is opposite to a second cabinet front wall on which a laundry loading opening is formed. Preferably, the reservoir is in fluid communication with a main container placed on a top region of the cabinet, a pumping device being provided for transferring condensate from reservoir to the main container. Preferably, an air filter extending substantially in a transverse direction relative to the drying air flow is provided in said basement region. Preferably, at least one condensate retaining region prevents drying air from by-passing the air filter. Preferably, the heat exchanger lays over a supporting surface that comprises one or more condensate guides for driving condensate towards the condensate draining path. Preferably, a further heat exchanger is provided for heating said drying air flow arranged in series with said moisture condensing heat exchanger, both heat exchangers laying over a supporting surface which is at least partly surrounded by the condensate draining path. Preferably, condensate guides comprise one or more walls extending transversally with respect to the direction along which the condensate draining path extends and sloping towards said path. Preferably, the basement region comprises a filter through which condensate is passed for removing impurities. Preferably, the condensate draining path comprises at least one condensate retaining region provided with a filter. Preferably, the basement comprises an air pumping device supporting seat having a through bore in fluid communication with reservoir. Preferably, a hose fluidly connects the air pumping device supporting seat and the reservoir, said hose comprising a condensate retaining region formed by a hose portion bent in a substantially U-shaped configuration. Preferably, the hose and the condensate draining path are arranged on opposite sides of the basement. Preferably, the portion of said condensate draining path extends on a basement region where drying air exiting the laundry container changes its flow direction from a substantially vertical plane to a substantially horizontal plane before entering said drying air moisture removing unit.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate possible embodiments of the invention and together with the description serve to explain the principles of the invention. Like reference numbers represents like features throughout the accompanying drawings, wherein:
With reference to
A laundry container comprising a drum (not shown) rotatably mounted within the casing 1. Further operational devices, such as heat exchanging devices, fluid conduits, fluid pumping devices and so on, for carrying out a drying treatment on laundry are provided within the casing 1. A front door 5, pivotally coupled to the front upright side wall 2A, is provided for closing a laundry loading opening allowing access to the drum interior region to place laundry to be treated therein.
An extractable moisture tank in the form of a drawer 6 is slidably arranged on the top of the casing 1, for being periodically emptied by a user in case the laundry dryer cannot be connected to a waste water net through a pipe. A user control interface 7 is arranged on the top of the casing 1 near the drawer 6 for input of laundry drying programs and displaying machine working conditions.
On a bottom inner portion of the casing 1 a basement 8, 108 is provided as supporting structure for operational devices of drying machine. In
A refrigerant fluid compressor (not shown) is received on its seat 12 and forms part of a heat pump system which is further provided with a refrigerant fluid evaporating unit and a refrigerant fluid condensing unit for respectively dehumidifying and heating drying air passing therethrough. Such evaporating unit and condensing unit may be accommodated on supporting surfaces 13, 14 formed onto basement 8. The refrigerant fluid condensing unit supporting surface 14 faces conduit 10 such that drying air heated by said condensing unit may be cyclically directed towards a fan inlet and then supplied to a laundry container.
A surface 15 is provided in a basement region 17 upstream of said refrigerant fluid evaporating unit supporting surface 13 considering the drying air flow direction schematically indicated by arrows A in
Since surface 15 faces the evaporating unit of the heat pump system, i.e. a heat exchanger capable of condensing moisture contained in drying air, and considering that chamber 16 receives drying air after it has just left the laundry container, i.e. air highly enriched in moisture, surface 15 is arranged to drain moisture that condenses before entering the evaporating unit. A portion of a condensate draining path 21, 29B, 30B is therefore provided on surface 15 of basement region 17, i.e. in a front portion thereof. As mentioned above surface 15 is slightly sloping towards the refrigerant fluid evaporating unit, therefore condensate may flow towards path 21 sliding on surface 15 under gravity force effect. Walls 35 protrude from surface 13 to form a condensate collecting portion 36 that, when filled with condensate, generates a liquid trap preventing drying air entering chamber 16 to by-pass filter 18 escaping underneath the latter. In this way drying air rich in fluff is not passed towards the evaporating unit without being filtered through filter 18. Since drying air within chamber 16 has not yet passed through fluff filter 18, moisture condensed in that basement region 17 may have a relatively large amount of fluff impurities dispersed therein, for this reason a filter 22 is preferably provided onto the surface 15. In this way, condensate is filtered by filter 22 before entering the draining path 21. In order to allow periodical cleaning of filter 22, the later is, preferably, associated to a removable support 23 mountable on surface 15 by arranging it on a region 29B formed on such surface 15 as shown in
As illustrated in
In practice, condensate draining path 21 extends along a basement portion 25, which is free from evaporating and condensing units that therefore do not rest on that portion of the basement 8
Each of said supporting surfaces 13 and 14 comprises at least one condensate guide 26 that extends transversally relative to condensate draining path 21 and has one or more walls 27, preferably sloping walls, integrally formed with basement 8 that extend transversally with respect to the extending direction of condensate draining path 21 and slope towards the latter such that condensate, under gravity force, flows to path 21. Further conveyors 28 configured and arranged for directing condensate towards sloping walls 27 are provided onto supporting surfaces 13 and 14, and such conveyors 28 may serve as resting surfaces for refrigerant fluid condensing and evaporating units.
As shown in
Condensate received within reservoir 24 is pumped up by a pumping device 43 to an extractable moisture tank in the form of a drawer 6 (
As disclosed in the attached Figures, condensate air path 21 extends at least partly within drying air circuit while reservoir 24 is placed outside such circuit, i.e. it is separated from drying circuit. Therefore, in order to prevent drying air drained together with condensate along path 21 from reaching and entering reservoir 24, one or more condensate retaining regions 29A, 29B are provided in the condensate draining path 21 and/or on reservoir 24. The aim of said retaining regions 29A, 29B is to create a liquid barrier or trap to air that may accidentally be drained, i.e. dispersed through path 21. This can be achieved, for example, by a siphon-shaped surface 30A that may have an outlet opening 36A placed either upstream of a passage 31 leading condensate from path 21 to reservoir 24 as depicted in
Since a high probability to drain drying air though condensate draining path 21 exists in the basement region 17 upstream of said refrigerant fluid evaporating unit supporting surface 13, it is preferred that a further condensate retaining region 29B (
Either of condensate retaining regions 29A, 29B may be integrally formed onto basement 8 as part of the condensate draining path 21.
A further way to provide a liquid trap to drying air may be that of keeping opening 31 under a water head. This may be achieved by increasing the minimum water level inside the reservoir 24 on which pumping device 43 is activated for pumping condensate up to the extractable moisture tank in the form of a drawer 6. A water level increase can be obtained, in principle, by moving pumping device 43 and the condensate level sensor 44 higher relative to the resting surface of basement 8 on a floor. The applicant has found that the positioning height of pumping device 43 and level sensor 44 must taking into consideration geometrical height dimensions of basement 8, and in particular level “H” of supporting surfaces 13, 14 and height “h” (
With reference to
A condensing unit (not shown) in the form of an air-air heat exchanger receives drying air in a direction schematically indicated by arrow “A” in
Condensing unit supporting surface 114 forms a part of a condensate draining path 121 extending in parallel with drying air flow and preferably made as integral part of basement 108. A further part of said path 121 extends transversally to the drying air flow in an edge region 125 of basement 108 and surrounds the supporting surface 114 for receiving condensate poured by the condensate guide 126 to lead it to reservoir 124.
Since condensate draining path 121 extends at least partly within drying air circuit while reservoir 124 is placed outside such circuit, i.e. it is separated from drying circuit. Therefore, in order to prevent drying air drained together with condensate along path 121 from reaching and entering reservoir 124, a condensate retaining region 129A is provided in the condensate draining path 121 in proximity of reservoir 124, preferably as an integral part of basement 108. As already described with reference to the first embodiment of basement 8, the aim of said retaining region 129A is to create a liquid barrier or trap to air that may accidentally be drained, i.e. dispersed through path 121. This can be achieved, for example, by a siphon-shaped surface 130A that may have an outlet opening which coincides with passage 131 to lead condensate from path 121 to reservoir 124, as shown in
In a further alternative embodiment the outlet opening can be provided downstream of opening 131.
With reference to
A surface 115 is provided in a basement region 117 upstream of said condensing unit supporting surface 114 considering the drying air flow direction schematically indicated by arrows A in
Since surface 115 faces the condensing unit, i.e. a heat exchanger capable of condensing moisture contained in drying air, and considering that chamber extending over surface 115 receives drying air after it has just left the laundry container, i.e. air highly enriched in moisture, surface 115 is arranged to drain moisture that condenses before entering the condensing unit. Therefore, a portion of a condensate draining path 121 may be provided on surface 115 of basement region 117, i.e. in a front portion thereof.
As it can be inferred from the description above, a laundry dryer according to the invention allows to collect moisture that may incidentally condense onto regions of the drying air circuit where temperature is favorable and to efficiently drain it towards a reservoir. In this way condensate formed on undesired regions of a drying air circuit does not represent a source of possible performance reduction for operational components of a laundry dryer.
Further advantageously a laundry dryer according to the invention has an efficient and reliable condensed moisture draining circuit interposing one or more physical, i.e. fluid, barrier to accidental passage of drying air from a drying air circuit to a reservoir where condensed water is collected.
Advantageously, fluff incidentally flushed away by condensing moisture from surfaces onto which it may be accumulated is prevented from reaching a reservoir where condensate is collected thereby avoiding damages to a pump provided for pumping condensate from said reservoir to a main water container.
The present invention can be applied to all machine suitable to carry out a drying treatment on laundry, i.e. it can be applied on a heat pump type laundry dryer, a condenser type laundry dryer or a washing-drying machine, that is a machine adapted to both washing and drying laundry.
Number | Date | Country | Kind |
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10192930.5 | Nov 2010 | EP | regional |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP11/70920 | 11/24/2011 | WO | 00 | 8/9/2013 |