CN114763667A - Laundry dryer with steam function and related operating method - Google Patents

Abstract

A laundry dryer (1) with steaming function, comprising: -a laundry treatment chamber (2), -a drying process air circuit (3), -a steamer (20), the steamer (20) comprising a steam generator (23), a steam injector (24) to inject steam into the treatment chamber (2), and a steam condensate conduit (40), the steam injector (24) being for conducting away any liquid condensed from the steam flow to be injected into the treatment chamber (2) by the steam injector (24); and-a siphonic trap (41), the siphonic trap (41) being arranged in the vapour condensate conduit (40) to receive vapour condensate from the vapour condensate conduit (40). In addition to the vapour condensate, the dryer also comprises an additional input (42) of liquid to the siphon trap (41). A method for operating a clothes dryer is also disclosed.

Description

Laundry dryer with steam function and related operating method

Technical Field

The present invention relates to a laundry dryer with steam function, and a related operating method. For the sake of brevity, such a machine will be referred to as a dryer hereinafter.

Background

Laundry dryers, such as tumble dryers, typically comprise a cabinet or casing containing a treatment chamber in which laundry to be treated can be loaded.

The laundry treatment chamber is generally a rotatable drum housed within a cabinet and rotatable with respect to an axis of rotation, which drum may be substantially horizontal or slightly inclined (in so-called "horizontal axis" laundry dryers), or substantially vertical (in so-called "vertical axis" laundry dryers), with respect to a horizontal surface on which the laundry dryer is disposed.

In known drum dryers, the drum is normally rotatably supported in the cabinet by rollers pivoted to a supporting structure stationary with respect to the cabinet; further support may be provided by a shaft defining the axis of rotation of the dryer and rotatably connected to the cabinet. In other known laundry dryers, the laundry treatment chamber is stationary with respect to the cabinet; in this case, the laundry dryer is a heating cabinet in which laundry may be suspended for drying.

In order to remove water and moisture from the laundry, the dryer generally uses a condensation process in which dry air is generally circulated through the process chamber and moisture is removed by condensation downstream of the process chamber, or a process in which air passes through the process chamber only once and is then discharged to the outside of the dryer as humid air. More particularly, the present invention relates to dryers of the aforementioned type, sometimes referred to as condensing dryers.

The laundry treatment quality of the dryer can be improved by using steam, which deodorizes and/or disinfects and/or (re) humidifies the laundry in a controlled manner, thereby having an anti-wrinkle/anti-crease effect and/or facilitating the subsequent ironing process.

For this reason, a dryer having a steam function is generally known. The steam engine injects steam of water vapor or water-based solution into the process chamber of the dryer during a steam program, which may be part of the drying program (usually the end part), or which may itself represent the complete running program.

In this specification and the appended claims, under "steam" water or water-based solution is meant a droplet-free vapour state, as opposed to atomized water or water-based solution, which contains small liquid droplets in air. The steam is typically hot water or superheated water or water-based solution steam.

In this specification and the appended claims, unless otherwise indicated, under "liquid" it is generally meant liquid water and/or liquid water-based solutions.

If the steam is not dry saturated steam, some liquid may enter the treatment chamber and wet the laundry. This may cause halo-like marks on the laundry, thereby impairing the result of the drying process, as well as other undesirable effects, such as the impression of a defective laundry dryer.

The steam engine generally comprises: a steam generator fluidly connected to a source of water and/or water-based solution, the steam generator may include a steamer liquid tank; a steam injector for injecting steam into the process chamber; and a steam delivery conduit connecting the steam generator to the steam injector.

Especially if the steam delivery duct connecting the steam generator and the steam injector is long, it may occur that the steam becomes too cold along the duct, causing some steam to condense at the injector, with the above-mentioned drawback of causing the laundry to become mottled damp.

Thus, such vapor condensate is typically collected at the bottom of the vapor injector (e.g., by appropriate configuration thereof) and carried away through a vapor condensate conduit, possibly to a collection vessel.

Since the pressure of the laundry treatment chamber may be higher than the pressure downstream of the steam condensate conduit, in particular higher than the pressure of said collecting container, where the steam condensate may collect, the steam may escape along the steam condensate conduit towards the collecting container instead of reaching the volume of the treatment chamber completely, thereby preventing an effective steam treatment of the laundry.

To avoid the above disadvantages, it is known, for example according to EP1959048B1 and WO2017/036553a1, to insert a siphon trap, for example a U-or S-trap, in the vapour condensate conduit. The liquid seal formed in the trap prevents vapor flow but still allows vapor condensate flow.

The applicant has perceived that also since the pressure inside the treatment chamber may be higher than the pressure downstream of the steam condensate conduit, in particular higher than the pressure of said collection container in which the steam condensate is driven by the steam condensate conduit and collected, a further drawback is that during the drying procedure the drying air circulating inside the laundry treatment chamber may escape through said steam condensate conduit, thereby dirtying the collection container due to fluff dispersed in the drying air circulating inside the treatment chamber. If the collecting containers are arranged in the same area where the drying air treatment devices, such as the heat exchangers of a heat pump system for dehumidifying and heating the drying air, are located, these devices may gradually become clogged, thereby losing their heat exchange performance. Furthermore, fluff entering the collecting container can be conveyed inside the dryer by air circulation and therefore clog other parts of the dryer, such as air ducts, fans for pushing drying air, etc.; or if the steam condensate is collected in a shared collecting container together with condensed moisture removed from the filtered drying air leaving the treatment chamber by condensation in the drying process air circuit, the fluff may be conveyed by a liquid flow in the dryer and the collected condensate is further (re-) circulated in the dryer.

The applicant has realised that the siphon trap described above is also beneficial in overcoming this disadvantage.

However, in order to function properly, the siphonic trap needs to contain enough liquid to form a liquid plug, and such a liquid plug should be available as soon as possible after the first operation of the dryer.

However, considering that the siphon trap is not filled with liquid by the dryer manufacturer, in the dryers according to the prior art, due to the hydraulic piping arrangement for discharging the steam condensate, the liquid plug is only available when running the drying program comprising the steam program or a stand-alone steam program. When the steaming process has not been performed or has not been performed for a long time, the siphonic trap is empty or becomes empty due to evaporation of the liquid plug, and then, when the drying process is run, the drying air leaves the treatment chamber through the steam condensate conduit, and fluff may circulate inside the dryer, with the consequent drawback, in addition to the fact that, at least during the initial phase of the steaming process of the laundry, there may be a loss of steam and/or steam pressure as described above.

Disclosure of Invention

The invention aims to provide a siphon trap which can reliably ensure the constant, rapid and effective operation of the siphon trap.

It is a further object of the present invention to provide frequent renewal of the liquid stopper in siphonic traps to keep the liquid stopper as clean as possible.

It is another object of the present invention to form a siphon trap without special requirements for the liquid stopper, thereby simplifying the use and operation of a clothes dryer with a steam function.

The applicant has found that in a laundry dryer with steam function comprising a siphon trap arranged in a steam condensation duct, the above object is achieved by additionally inputting liquid water (or liquid water-based solution) to the siphon trap during a steam program, possibly part of a drying program, instead of relying solely on the amount of liquid condensed from the steam at the steam injector, the liquid water flowing along the steam condensation duct in which the siphon trap is formed. By virtue of this arrangement, the siphonic trap is quickly filled and refurbished, and thus ensures that the siphonic trap will function properly to prevent any airflow from entering the vapor condensate conduit, thereby inhibiting fluff from the treatment chamber from propagating within the clothes dryer. Furthermore, the loss of steam and/or steam pressure is reduced.

Further, the applicant has found a method for operating a laundry dryer with steam function to achieve the above object.

In a first aspect, the present invention relates to a laundry dryer with steam function, comprising:

-a laundry treatment chamber for treating laundry,

a drying process air circuit having a first air opening for guiding a process air flow into the process chamber and a second air opening for exhausting the process air flow from the process chamber, the drying process air circuit further comprising a heater for heating the process air, a fan for moving said process air flow along the drying process air circuit, and a condenser for removing moisture from the process air flow leaving the chamber,

-a steamer comprising a steam generator, a steam injector to inject steam into the process chamber, and a steam condensate conduit for conducting away any liquid condensed from the steam flow to be injected into the process chamber by the steam injector, and

a siphon trap arranged in the vapour condensate conduit to receive vapour condensate from the vapour condensate conduit,

characterized in that the dryer comprises, in addition to the vapour condensate, an additional liquid feed of liquid to the siphon trap.

An additional input is provided for filling the siphonic trap and forming and/or maintaining a liquid plug that may be refurbished even in the absence of steam condensate available.

The additional input may be fluidly connected to a water source or a water-based solution source, such as through a conduit.

The additional input may be fluidly connected to receive at least one of:

● the condensed water is recycled to the evaporator,

● the vapor condensate is recycled and,

● overflow liquid from the steam engine liquid tank and/or the steam engine manual loading unit,

● is supplied by the user.

Preferably, the additional input is configured such that the percentage of liquid input to the additional input that contributes to the formation of a liquid plug in the siphonic trap is up to 50%, preferably up to 20%.

Preferably, the additional input to the siphonic trap is connected to a recirculation loop which is fluidly supplied with condensed moisture from the process air in the dry process air loop. This arrangement helps to ensure that the liquid plug is formed quickly.

More preferably, the recirculation loop also recirculates the vapor condensate.

More specifically, preferably, the additional input to the siphonic trap is fluidly connected to a hopper positioned to:

● receive liquid input by a user into the hopper, and/or

● collects any spilled liquid from at least one of:

the liquid tank of the steamer is rated as o,

manual loading unit of the liquid tank of a steamer, and

removable tank of recirculation loop.

Advantageously, with this arrangement, the suction of liquid by the siphon trap disturbs as little as possible other parts of the liquid circuit of the dryer, in particular the liquid level in the liquid tank of the steam engine. This arrangement also helps to ensure that the liquid plug is formed quickly.

More specifically, it is preferred that the additional input of the siphonic trap is connected to a recirculating liquid conduit leading recirculating liquid from the hopper to a collection vessel for collecting condensed moisture from the drying process air circuit and/or steam condensate from the steamer, preferably at least for collecting condensed moisture from the drying process air circuit.

Thus, the downstream end of the siphonic trap may be connected to the collection container, or it may be connected to the recirculation loop downstream of the collection container, or it may be connected to a second dedicated collection container of the recirculation loop, so that steam condensate may also be recirculated within the laundry dryer.

Alternatively or additionally to the above features, an additional input to the siphonic trap may be located partially within the outlet area of the siphonic trap such that only the amount of liquid required to form or maintain the liquid plug enters the U-shaped portion of the siphonic trap.

Preferably, the additional input to the siphonic trap is located at the uppermost region of the downstream side of the siphonic trap, in particular at the convex surface of the inverted U-shaped portion of the S-shaped siphonic trap.

In this way, the incoming liquid, particularly the recycled liquid, will be split into two streams, one of which may fill the siphonic trap itself, while the other stream may be recycled or may be removed.

Preferably, the siphon trap is an S-shaped siphon trap, the additional input to the siphon trap being located on the mid-plane of the inverted U-shaped portion of the siphon trap but asymmetric with respect to the mid-plane of the inverted U-shaped portion of the siphon trap. In this way, the two streams into which the input liquid is readily split may have a desired flow ratio other than 50: 50.

More preferably, the additional input of the siphonic trap is displaced towards the outlet branch of the siphonic trap such that the percentage of liquid flowing to the siphonic trap is up to 50% but not 50% and preferably up to 20%.

In this way, when the incoming liquid rate flow is relatively large, if this can happen when the incoming liquid is a recirculating liquid, only the amount of liquid required to form the liquid plug enters the U-shaped portion of the siphonic trap, however, the recirculating liquid is primarily conveyed directly again in the recirculation loop to, for example, a collection vessel.

Alternatively or additionally to the above feature, preferably the joint for connecting the conduit to the additional input is formed in one piece with the siphon trap. This avoids the need for external fittings, such as tees, and greatly facilitates the assembly and installation process.

Alternatively or additionally, it is preferred that the dryer comprises a self-standing body containing a siphonic trap and optionally a joint for connecting the conduit to an additional input.

In the present description and in the appended claims, by free-standing body is meant a body having sufficient rigidity to maintain its shape under normal conditions of use, and in particular to act as a siphon trap as opposed to a hose.

More preferably, the free-standing unitary body is a blow-molded part made of a polymeric material.

Additionally or alternatively, the free-standing, one-piece body preferably further comprises a flange for mounting to a cabinet of the dryer.

In a second aspect thereof, the present invention relates to a method for operating a laundry dryer with steam function as described above, comprising forming a liquid plug in the siphonic trap by:

a1) a drying procedure is carried out in such a way that,

a2) collecting condensed moisture from the laundry being dried during the drying program, an

a3) Part of the collected condensed moisture is input to the siphon trap,

and/or by:

b1) a liquid, in particular water or a water-based solution, is manually input into a steamer liquid tank of the steamer, preferably by a manual loading unit of the steamer liquid tank, an

b2) A portion of the manually input liquid is deflected to a siphonic trap.

The method may further comprise recirculating within the dryer condensed moisture formed during the laundry drying process and steam condensate which may be formed during the steam process.

The method may further include deflecting a portion of the recirculated liquid toward the siphonic trap to form a plug of liquid in the siphonic trap.

Alternatively or additionally, the method may further comprise obtaining the liquid for forming the liquid plug by:

● receive liquid manually input by a user, and/or

● collect spilled liquid from one or more of:

the liquid tank of the steamer is rated as o,

manual loading unit of the liquid tank of a steamer, and

removable tank of recirculation loop.

Drawings

Other features and advantages of the present invention will be more clearly understood from the following detailed disclosure of some embodiments of the invention, taken in conjunction with the accompanying drawings, in which:

figure 1 is a block diagram of a condensing laundry dryer according to an embodiment of the present invention,

figure 2 is a schematic view showing the components of a laundry dryer according to several options of the present invention,

fig. 3 is a perspective view of a condensing laundry dryer according to an embodiment of the present invention, wherein some walls and some parts of the cabinet are removed,

fig. 4 is a side view of the laundry dryer of fig. 3, with some walls of the cabinet removed,

figure 5 is a different perspective view of a detail of the laundry dryer of figure 3, an

Figures 6 and 7 are two different perspective views of the components of the laundry dryer of figure 3.

Detailed Description

In fig. 1, a block diagram of a condensing laundry dryer 1 according to the present invention is shown. In fig. 1, the air path is schematically represented by hollow solid arrows, and the liquid path is schematically represented by solid arrows: those skilled in the art will appreciate that such a path may be achieved by any suitable means, such as a pipe, hose, tube, conduit, guide or the like, although the conduit will be referred to hereinafter by way of example. Further, the hollow dotted arrows schematically represent liquid input/output to/from the dryer by hand.

Dryer 1 comprises, inside a cabinet not completely shown in the figures but comprising a front wall and a rear wall: two side walls and a top wall, both resting on the base (see base 60 in fig. 3 to 5); a treatment chamber 2, which treatment chamber 2 is accessible from the outside, such as from an opening at the front wall of the cabinet, can be tightly closed by a pivoting door, and is intended to temporarily store laundry to be treated (not shown) during one or more treatment programs. The chamber 2 may for example be a fixed compartment or a drum pivoted to a fixed support structure and/or rotatably supported for example by rollers as discussed in the introductory part of the present disclosure.

Dryer 1 comprises a drying process air circuit 3.

The drying process air circuit 3 comprises a heater 4, which may be, for example, an electric heater, a condenser of a heat pump system or a gas burner, and a fan 5 or other air forcing means for generating a forced hot drying process air flow 6 through the chamber 2 through a first air opening 6 a. The hot drying process air stream 6 dries the laundry inside the chamber 2, cools down and leaves the process air stream 7 as moisture-containing air through a second air opening 7a, which moisture-containing process air stream 7 is fed to a condenser 8, also referred to herein as dryer condenser 8, of the drying circuit 3. In the closed process air loop, a condenser 8 (which may be, for example, an evaporator of a heat pump system, or an air-to-air exchanger) removes moisture from the moisture-laden process gas stream 7, and the dried and cooled process gas stream 9 leaving the condenser 8 is heated and forced through the chamber 2 again by the heater 4 and fan 5.

A filter 10 is provided downstream of the chamber 2 and upstream of the condenser 8 for retaining fluff released by the laundry being dried.

It should be noted that the above-mentioned components 4, 5, 8, 10 of the drying process air circuit 3 can be arranged differently along the drying process air circuit 3.

Furthermore, the dry process air circuit 3 does not necessarily need to comprise a closed process air loop as shown in fig. 1; instead, a dried and cooled process air stream 9 may be provided to the environment, and ambient air may be fed to the heater 4 and the fan 5 to form the forced hot drying process air stream 6.

Condensed moisture from dryer condenser 8 is collected at collection vessel 11 by condensed moisture conduit 12.

As shown, the collecting container 11 is preferably located at the bottom of the dryer 1, integral with its base 60 (see fig. 3 to 5), which also carries a motor (not shown) in the case of the chamber 2 being a rotatable drum.

The heat exchanger (heater 4 and condenser 8) and fan 5 are typically housed in the same space as the collection container 11. The base 60 (see fig. 3 to 5) is therefore itself typically part of the drying process air circuit 3.

A pump 13 is provided to pump condensed moisture and vapour condensate, as described below, out of the collection container 11 and into a removable tank 14, which removable tank 14 is typically easily accessible from the top and/or front of the dryer 1, and is preferably configured as a drawer. The removable tank 14 is intended to be emptied by a user, as schematically shown by hollow dashed arrow 14 a. The position of the removable tank 14 at the top of the dryer 1 makes the emptying operation more comfortable for the user.

The liquid conduit output from the pump 13 is referred to herein as the riser conduit 15.

A hopper 16 is provided below the removable tank 14 to collect any spilled liquid (as schematically shown by aperture 14 b) if a user fails to empty the removable tank 14 when needed and/or during removal of the removable tank 14. Liquid falling into the hopper 16 is also collected at the collection vessel 11 by means of the recirculating liquid conduit 17.

The liquid recirculation circuit of dryer 1 therefore comprises a collection container 11, a pump 13, a removable tank 14 and a hopper 16.

During the drying program, a variable amount of condensed moisture is removed from the laundry and stored in a removable tank 14, the collecting container 11 representing a buffer liquid container.

Note that the pump 13 is switched on and off by a controller (not shown) depending on the level of liquid in the collection container 11, and the pump 13 will remain switched on as long as the user fails to empty the removable tank 14. The controller may be configured to disconnect the drying process air circuit 3 and/or issue an alarm after a time interval when the pump 13 is continuously on, which status indicates that the removable tank 14 is full.

The dryer 1 further includes a steam engine 20.

The steamer 20 comprises a steamer liquid tank 21, a steamer pump 22, the steamer pump 22 transporting liquid (liquid water and/or liquid water based solution) from the steamer liquid tank 21 to a steam generator 23, and a steam injector 24, the steam injector 24 being suitably placed at the process chamber 2 for injecting steam into the process chamber 2. The steamer liquid tank 21 and the steamer pump 22 may also be absent and replaced by a direct supply of liquid to the steam generator 23 by means of a valve, such as water from a supply such as a tap water pipe.

Also shown is an optional drain conduit 25, also referred to as a "winter conduit," for draining the steam engine liquid tank 21 when needed or desired. The exhaust conduit 25, if provided, may branch off from the intake conduit 26 of the steam engine transfer pump 22, for example, by a T-fitting 27, and be closed at its other end by a removable plug (not shown).

The steam generator 23 may comprise, for example, a water heater or a pipe section or vessel in which the resistor is immersed in a layer of liquid. Steam is supplied by the steam generator 23 and, when it reaches the steam injector 24 through the steam delivery duct 28, it diffuses into the chamber 2 to treat the laundry.

The steam engine liquid tank 21 can be replenished by a user, for example, by a manual loading unit 29, which manual loading unit 29 is typically easily accessible from the top and/or front of the dryer 1. The hollow dotted arrow 29a schematically represents the manual supply of liquid to the manual loading unit 29. The actual configuration of such a manual loading unit 29 is not relevant to the present invention and is therefore not described in detail. A manual loading unit 29 is fluidly connected to the steamer liquid tank 21, such as by conduit 30.

The amount of liquid used by the steamer 20 during the steaming sequence is variable, but not negligible. To avoid the need for the user to replenish the steam engine liquid tank 21 frequently, it may also receive recirculated liquid, preferably connected in the same recirculation loop used to recirculate the condensed moisture.

To this end, a conduit, referred to herein as a steam engine make-up conduit 31, may branch off from riser conduit 15 (delivered from pump 13) through a T-joint 32, for example, leading to a manual loading unit 29 as shown. Alternatively, the steamer makeup conduit 31 may lead directly to the steamer liquid tank 21.

It should be noted that the steamer liquid tank 21 is normally sealed to prevent liquid spillage if it is full, for example while the pump 13 is still running and/or during user replenishment, into the manual loading unit 29 (through conduit 30) and then out of the manual loading unit 29 (as schematically shown by orifice 29 b).

The hopper 16 is preferably positioned to also collect this spilled liquid from the manual loading unit 29. As mentioned above, the liquid falling into the hopper 16 is collected at the collection container 11 through the recirculating liquid conduit 17. Alternatively, there may be a second hopper (not shown) dedicated to manual loading unit 29 and suitably connected to collection container 11 or elsewhere within the recirculation circuit.

As discussed in the introductory part of the present description, the steam injector 24 is suitably configured in a manner well known per se to avoid liquid entering the chamber 2, in which chamber 2 the liquid may undesirably wet the laundry, thereby causing disadvantages.

This liquid is mainly generated (except for possible failures due to the steam generator 23) because the steam cools down along its delivery duct 28, and the longer the delivery duct 28, the greater the amount of liquid condensed at the steam injector 24, and therefore removed before it enters the chamber 2.

Liquid or vapor condensate removed from the vapor stream at the vapor injector 24 upstream of the process chamber 2 is received and directed away by the vapor condensate conduit 40.

The steam condensate conduit 40 is advantageously fluidly connected to the same collection vessel 11, wherein also the moisture condensed during the drying procedure and/or the liquid collected by the hopper 16 (and possibly a second hopper dedicated to the liquid overflowing from the steamer liquid tank 21 and/or the manual loading unit 29) is collected for pumping to the removable tank 14 and/or the steamer liquid tank 21 in question. Alternatively, the vapor condensate conduit 40 may be fluidly connected to the recirculation loop downstream of the collection vessel 11 at the inlet of the pump 13, or to a second collection vessel (not shown) that is suitably fluidly connected to the pump 13 or to a second pump (not shown). In this way, the liquid removed from the flow of steam before it reaches the chamber 2 can be advantageously recovered.

Thus, the liquid recirculation circuit of dryer 1 preferably additionally comprises a manual loading unit 29, a steamer liquid tank 21 and a steam condensate conduit 40 (as well as a second hopper, a second collection vessel and/or a second pump, if provided).

It is noted, however, that vapor condensate may also be removed.

It should be understood that a liquid separator distinct from and immediately upstream of vapor injector 24 may be provided, with vapor condensate conduit 40 then being fluidly connected to the liquid separator rather than vapor injector 24.

As discussed in the introductory part of the present description, since the pressure of the laundry treatment chamber 2 may be higher than the pressure downstream of the steam condensate conduit 40, in particular higher than the pressure inside the collecting container 11 collecting the steam condensate and/or the condensed moisture, drying process air and entrained fluff may escape along the steam condensate conduit 40 towards the collecting container 11; furthermore, during the steam program, steam may escape instead of completely reaching the volume of the treatment chamber 2, thereby preventing an effective steam treatment of the laundry contained therein. Similar disadvantages occur when the vapor condensate conduit 40 is fluidly connected to the recirculation loop, and partially occur even when vapor condensate is removed, according to any of the above alternatives.

To overcome such a disadvantage, a siphon trap 41 is formed in vapor condensate conduit 40 to receive vapor condensate from the siphon trap. For the sake of simplicity, reference will be made below only to the case where the steam condensate conduit 40 is fluidly connected to the collection vessel 11, other alternatives being applicable where necessary, as will be readily understood by those skilled in the art in light of the present disclosure.

The siphonic trap 41 may be an S-shaped trap as shown, or it may be a U-shaped trap.

The liquid plug formed in such a siphon trap 41 prevents any process air entering the vapor condensate conduit 40 from the vapor injector 24 from exiting downstream of the siphon trap 41, and in particular from reaching the collection vessel 11.

Advantageously, the liquid plug also prevents any fluff that may form in the chamber 2 during the drying procedure from reaching the collection container 11 and its downstream components, which fluff may also circulate as airborne fluff and/or liquid-borne fluff. If fluff is allowed to propagate, the fluff may undesirably soil the collection vessel 11, clog the heater 4, the dryer condenser 8, the pumps 13, 22, the fan 5, and/or reduce the performance of the steam generator 23, and/or re-soil the laundry.

In addition, the liquid plug also limits the amount of vapor that leaks from the treatment chamber 2 to that contained along the vapor condensate conduit 40 upstream of the siphonic trap 41. Therefore, the steam flow rate input to the chamber 2 is not disadvantageously reduced.

Rather, the siphonic trap 41 suitably allows condensed liquid (i.e., vapor condensate) to flow through the siphonic trap 41.

However, to be effective, such a liquid plug must indeed be present in the siphonic trap 41. On the other hand, when dryer 1 is first operated to run a steam program after shipment, and/or after vapor-liquid tank 21 is emptied, for example, in winter to avoid ice formation, the vapor condensate collected at steamer infuser 24 will be insufficient to form the necessary liquid plug in siphonic trap 41. Further, even after the liquid stopper has been properly formed in the siphon trap 41, such a situation may occur: if a steam program, which is usually an optional program during the drying program and rarely performed as a separate program, is not performed for a period of time, the liquid plug naturally evaporates to such an extent that it is no longer effective.

In dryer 1 according to the present invention, in addition to vapor condensate from vapor injector 24 along vapor condensate conduit 40 (or from a different liquid separator upstream thereof) in which siphonic trap 41 is formed, an additional input 42 of liquid is provided to siphonic trap 41.

The additional input 42 is used to fill the siphon trap 41 and form and/or maintain a possible renewed liquid plug, even when no vapor condensate is available.

Such additional input 42 may take liquid from any suitable source of liquid (water or water-based solution) external to or internal to dryer 1.

In a particularly advantageous manner, as shown in fig. 1, an additional input 42 to the siphon trap 41 is connected to the recirculation circuit of the dryer 1, in particular to the recirculation liquid conduit 17, which is fluidly connected to the hopper 16 as shown.

Preferably, the hopper 16 is also accessible from the outside, to receive the liquid directly from the user, as schematically illustrated by the hollow dashed arrow 16 a.

In this manner, siphonic trap 41 is liquid fed from hopper 16, and hopper 16 is in turn liquid fed with:

● utilize condensed moisture that is recirculated to the removable tank 14 by the dry process air program, but spills over from the removable tank 14, and/or

● utilize steam condensate that is recirculated to the removable tank 14 through the steam program, but spills over from the removable tank 14, and/or

● utilize liquid spilled through the steamer liquid tank 21 and/or its manual loading unit 29, and/or

● utilize liquid that is directly input into the hopper 16 by a user.

It is immediately recognized that the risk of the siphonic trap 41 remaining empty or becoming empty, if not completely empty, becomes very low. Even if the user fails to directly input liquid (via manual loading unit 29) and/or replenish steamer liquid tank 21, the liquid plug will provide condensed liquid from any laundry drying program that does not necessarily include a steaming program to be maintained or very quickly formed in siphonic trap 41. There is no need to introduce any new liquid into siphon trap 41, for example water taken from the mains, but it is possible, for example, to introduce new liquid when installing laundry dryer 1, so as to immediately form a liquid plug within siphon trap 41, thereby immediately preventing any fluff propagation and even making it possible to first operate dryer 1 in a pure steam program.

Furthermore, even in the case where the steam generated by the steam generator 23, whose pressure is significantly higher than the atmospheric pressure at the collection container 11, is not completely injected into the treatment chamber 2 at the steam injector 24 for some reason to reach the siphon trap 41, the liquid stopper is pushed out of the siphon trap 41 and is quickly restored.

As discussed and shown in fig. 1, recirculation liquid loop 17 extends between hopper 16 and siphon trap 41 at additional input 42 of siphon trap 41. Thus, advantageously, the recirculating liquid from the hopper 16 reaches the collecting container 11 through the siphon trap 41 itself. Furthermore, the liquid intake through siphon trap 41 disturbs the other components of the liquid circuit of dryer 1, in particular the liquid level in the liquid tank 21 of the steam engine, as little as possible.

In practice, it is noted that the flow rate of liquid from the hopper 16 (or generally from a liquid source) may be substantial, and therefore it may not be desirable to have all such flow rates involve a siphonic trap 41. This can be addressed by having only a fraction of the recirculated liquid from hopper 16 reach siphon trap 41, for example up to 50%, preferably up to 20%. More generally, the additional input 42 is preferably configured such that the percentage of liquid input that contributes to the formation of a liquid plug in the siphonic trap 41 is up to 50%, preferably up to 20%.

A preferred arrangement for achieving the above objective is further discussed below with reference to fig. 2.

A portion of a vapor condensate conduit 40 including an S-shaped siphon trap 41 is schematically illustrated in fig. 2. The empty arrows indicate the flow of vapor condensate and the dashed arrows indicate the flow according to several possible input points 42 (schematically indicated as holes) along the siphon trap 41 to the additional liquid input of the siphon trap 41 and which flow after the formation of the liquid plug 44 flows out from the input points 42 (also indicated as another comparative input 53 along the vapor condensate conduit 40).

The additional input 50 is located at a preferred location on the convex surface of the inverted U-shaped portion of the siphonic trap 41, i.e., the uppermost region on the downstream side of the siphonic trap 41.

In fig. 2, the liquid plug 44 is shown in an intermediate state during its formation or evaporation. It will be appreciated that when the liquid plug 44 is fully formed, the free surface of liquid will reach this uppermost region and then begin to exit the siphonic trap 41 along the outlet branch 46.

More preferably, the additional input 50 is located on the medial face 45 of the inverted U-shaped portion and thus partially within the outlet region 54 of the siphonic trap 41. By so placing the additional input 50, the flow of liquid from an additional source, such as from the hopper 16, will be split into two branches of the inverted U-shaped portion, i.e. in the outlet branch 46 to reach for example the collection container 11, and in the intermediate branch 47 to form the liquid plug 44.

More preferably, the additional input 50 is asymmetrically positioned about the mid-plane 45 such that the flow of liquid entering the additional input 50 will be diverted into the two branches 46, 48 at different percentages in order to easily accommodate different flow requirements.

More preferably, as shown, additional input 50 is displaced toward outlet branch 46 of siphonic trap 41 such that the percentage of liquid flowing toward siphonic trap 41 and contributing to forming liquid plug 44 is lower than the percentage of liquid flowing directly toward collection container 11 or more generally toward the recirculation loop.

Preferably, if the additional input 50 is configured such that liquid is injected therein in a direction parallel to the mid-plane 45, the ratio of the area of the additional input 50 on the outlet branch side of the mid-plane 45 to the area of the additional input 50 on the mid-branch side of the mid-plane 45 is in the range from about 50:50 (i.e., the additional input is not displaced towards the outlet branch 46) to about 80:20 such that the percentage of liquid flowing to the siphonic trap 41 to form the liquid plug 44 is up to 50%, preferably up to 20%.

In the case where the additional input 50 deviates from a direction parallel to the median plane 45, the position of the additional input 50 may also take into account the liquid injection direction as appropriate. As will be appreciated, the more liquid is injected toward the outlet branch 46, the lower the percentage of liquid that contributes to forming the liquid plug 44. Conversely, it will be appreciated that the liquid injection direction may be adjusted by adjusting the mutual inclination of the conduits connected to the additional input 50 (and, in turn, by appropriately configuring the additional input) and/or by providing baffles or other deflection means at the additional input 50.

Other locations for additional inputs 42 are possible when, conversely, it is not desirable to provide only a portion of the additional input liquid to assist in forming the liquid plug 44.

An additional input 51 (shown only as an example on the outside) at the input branch 48 of the siphon trap 41 is an option.

The additional input 52 at the middle branch 47 of the siphon trap 41 (shown only as an example on the inside) is also an option, but in order to reach the outlet branch 46 the liquid should flow in a counter-current direction.

For completeness, fig. 1 shows another input 53 upstream of the siphonic trap 41, which would be an indirect input to the siphonic trap 41, i.e., at a location along the vapor condensate conduit 40 above the maximum level of the free surface of the liquid plug in the input branch 48 of the siphonic trap 41; in contrast, such another input is not an option for the additional input 42 of the siphonic trap 41, as it will not be sealed by a liquid plug during operation of the laundry dryer, and it will provide a path for fluff-laden process air and/or steam to escape.

It will be appreciated that where the siphon trap 41 is a U-shaped trap, the preferred location of the additional input 42 will still be in its outlet region at the uppermost region on the downstream side of the siphon trap 41, where there is a maximum level of free surface of the liquid plug. Those skilled in the art will appreciate that the specific location and/or inclination and/or other flow separation configurations described above with respect to the additional input will apply as necessary.

In addition to or as an alternative to the above-described configuration of additional input 42, recirculation liquid conduit 17 (or any other conduit leading to additional input 42) may be branched, for example with a T-joint, to include a branch leading to siphonic trap 41 and a branch leading directly to collection vessel 11 (or any other point of the recirculation circuit of dryer 1), the two branches being appropriately sized relative to each other to achieve the desired flow separation.

In fig. 3 and 4, a condensing type laundry dryer 1 according to an embodiment of the present invention is shown, in which some walls and some components of the cabinet are removed. The components of dryer 1 have been identified with the same reference numerals as used in figure 1 above.

Further shown is a base 60, the collection container 11 being integrally formed within the base 60 such that they are integral.

A rear wall 61 of the cabinet is shown, a first air opening 6a is formed in this rear wall 61 (although the first air opening 6a is not visible in fig. 3 to 5), and a cover (not shown) is applied over the rear wall 61 to form part of the drying process air circuit 3 upstream of the first air opening 6 a.

Also shown is a post 62 extending from the base 60, the post 62 having a hollow portion containing a portion of the drying process air circuit 3 downstream of the second air opening 7 a.

With particular reference to fig. 5-7, preferably siphon trap 41 may be integrated with joint 70 at its additional input 42, which additional input 42 is located in the case shown at the preferred location described with reference to additional input 50 for connection to a conduit for supplying liquid to additional input 42, in particular recirculating liquid conduit 17. As shown, the fitting 70 may be a short length of conduit with a tapered free end.

As shown, a joint or tapered free end may also be provided at the input branch 48 and/or the outlet branch 46 to facilitate connection with a corresponding connecting member. The integral joint 70 (as well as other integral joints) avoids the need for joints such as T-joints and greatly facilitates the assembly and installation process.

As shown, the joint 70 may also be suitably angled with respect to the siphonic trap 41 for reasons detailed above. Specifically, the joint 70 is skewed to facilitate the injection of more liquid toward the outlet branch 46 relative to the middle branch 47 of the siphonic trap 41.

Additionally or alternatively, the siphonic trap 41 may preferably be formed as a self-standing body 71. Preferably, the free-standing body 71 is obtained by a blow-moulding process from a suitable plastic material, such as HDPE (high density polyethylene).

As shown, in addition to the siphonic trap 41 and the preferred joint 70, the self-standing body 71 preferably includes at least one of:

●, the thin member 72 extending between a portion of the input branch 48 and a portion of the intermediate branch 47,

●, a thin member 73, the thin member 73 extending between a portion of the outlet branch 46 and a portion of the intermediate branch 47,

●, a thin folding member 74, the thin folding member 74 extending transversely from a portion of the input branch 48.

The thin folding member 74 is preferably sized and shaped to mate with the upright 62 thereof when properly installed in the clothes dryer 1 so as to allow the siphonic trap 41 to be stably attached to the cabinet of the dryer 1. The thin folded member 74 may for example comprise holes 75 in its folded edge 77 for screws 76 (fig. 5). Thus, the folding member 74 comprises the mounting flange of the self-standing body 71.

Preferably, as shown, the outlet branch 46 and the intermediate branch 47, as well as the thin member 73 extending therebetween, are bent so as to be spaced apart with respect to the median plane of the thin member 72, so as to allow easy access to the hole 75 by a tool, such as a screwdriver, for acting on the screw 76.

It will be appreciated that dryers other than that shown in fig. 3 to 5 may also be provided with the siphon trap 41 as a free standing body 71 and/or with an integral joint 70 as described above and/or when the conduit providing liquid to its additional input 42 is other than the recirculating liquid conduit 17, for example a conduit connected to the steamer liquid tank 21. Accordingly, the overall shape of the siphon trap 41 and/or the self-standing body 71 including the siphon trap 41 may be different from the shape shown in fig. 5 to 7.

It will be appreciated that there has been disclosed above a method for operating the above-described condensation dryer 1 with steam functionality, the method comprising forming a liquid plug 44 in the siphon trap 41 by:

a1) a drying procedure is carried out in such a way that,

a2) collecting condensed moisture from the laundry being dried during the drying process, an

a3) A part of the collected condensed moisture is inputted to the siphon trap 41.

Additionally and/or alternatively, the method for operating the above-described condensation-type laundry dryer 1 with steam function may comprise forming a liquid stopper 44 in the siphon trap 41 by:

b1) a liquid, in particular water or a water-based solution, is manually input into the steam engine liquid tank 21 of the steam engine 20, preferably by means of a manual loading unit 29 of the steam engine liquid tank 21, an

b2) A portion of the manually input liquid is deflected to the siphonic trap 41.

The operating method may also include recirculating within dryer 1 condensed moisture formed during the drying process and steam condensate that may be formed during the steam process.

The method of operation may further include deflecting a portion of the recirculated liquid toward the siphonic trap 41 to form a liquid plug 44 in the siphonic trap 41.

Alternatively or additionally, the operating method may further comprise obtaining the liquid for forming said liquid plug 44 or liquid plug 44 by:

● receive liquid manually input by a user, and/or

● collect spilled liquid from one or more of:

the liquid tank 21 of the steam engine,

the manual loading unit 29 of the steamer liquid tank 21, and

removable tank 14 of the recirculation loop.

As used herein, the term "about" means that the recited values are approximations, and minor variations do not materially affect the practice of the invention. Where numerical limitations are used, unless the context indicates otherwise, "about" means that the numerical values can vary by ± 10%, but still remain within the scope of the disclosed subject matter.

Throughout the specification and claims, unless the context requires otherwise: the form of the verb "to comprise" is to be interpreted in an open, inclusive sense as "comprising, but not limited to"; the singular forms "a", "an" and "the" are to be construed in an open, inclusive sense and are not limited to "a single"; the term "or" is generally used in its broadest sense, such as "and/or".

The foregoing is a description of various embodiments of aspects of the present invention, and other changes may be made without departing from the scope of the invention. The shape and/or size and/or position and/or orientation of the various components and/or the order of the various steps may be changed. The functions of an element or module may be performed by two or more components or modules, and vice versa. Components that are shown directly connected or contacting each other may have intermediate structures disposed between them. The steps shown immediately may be intermediate steps performed between them. The details shown in the figures and/or described with reference to the figures or embodiments may be applied to other figures or embodiments. All details shown in the figures or described in the same context need not necessarily be present in the same embodiment. The features or aspects that demonstrate innovation relative to the prior art, alone or in combination with other features, should be considered as descriptive in itself regardless of what is explicitly described as innovative.

Claims (15)

1. A laundry dryer (1) with steam function, comprising:

-a laundry treatment chamber (2),

-a dry process air circuit (3), the dry process air circuit (3) having a first air opening (6a) to direct a process air flow (6, 7, 9) into the process chamber (2) and a second opening (7a) to exhaust a process air flow (6, 7, 9) from the process chamber (2), the dry process air circuit (3) further comprising a heater (4), a fan (5) and a condenser (8), the heater (4) being for heating process air, the fan (5) being for moving the process air flow (6, 7, 9) along the dry process air circuit (3), the condenser (8) being for removing moisture from the process air flow (6, 7, 9) leaving the chamber (2),

-a steamer (20), the steamer (20) comprising a steam generator (23), a steam injector (24) to inject steam into the process chamber (2), and a steam condensate conduit (40) to draw off any liquid condensed from the steam flow to be injected into the process chamber (2) by the steam injector (24), and

-a siphonic trap (41), the siphonic trap (41) being arranged in the vapor condensate conduit (40) to receive vapor condensate from the vapor condensate conduit (40),

characterized in that, in addition to the vapour condensate, an additional input (42, 50, 51, 52) of liquid to the siphon trap (41) is included.

2. The laundry dryer (1) according to claim 1, wherein said additional input (42, 50, 51, 52) is fluidly connected to receive at least one of:

the recycling of the condensed water content,

the recycling of the vapour condensate is carried out,

-overflow liquid from a steam engine liquid tank (21) of the steam engine (20) and/or a manual loading unit (29) of the steam engine liquid tank (21),

liquid provided by the user.

3. The laundry dryer (1) according to any of the preceding claims, wherein said additional input (42, 50) is configured such that the percentage of liquid input to said additional input (42, 50) contributing to the formation of a liquid plug (44) in said siphonic trap (41) is up to 50%, preferably up to 20%.

4. Laundry dryer (1) according to any of the preceding claims, wherein said additional input (42, 50, 51, 52) to said siphonic trap (41) is connected to a recirculation circuit which is fluidly supplied with condensed moisture from the process air in said dry process air circuit (3).

5. Laundry dryer (1) according to claim 4, wherein said recirculation circuit also recirculates steam condensate.

6. Laundry dryer (1) according to any of the preceding claims, wherein said additional input (42, 50, 51, 52) to said siphonic trap (41) is fluidly connected to a hopper (16), said hopper (16) being positioned:

receiving liquid input by a user into the hopper (16), and/or

Collect any overflow liquid from at least one of:

a steamer liquid tank (21),

-a manual loading unit (29) of the steamer liquid tank (21), and

-a removable tank (14) of the recirculation circuit.

7. Laundry dryer (1) according to claim 6, wherein said additional input (42, 50, 51, 52) of said siphonic trap (41) is connected to a recirculating liquid conduit (17), said recirculating liquid conduit (17) guiding recirculating liquid from said hopper (16) to a collecting container (11), said collecting container (11) being intended to collect condensed moisture from said drying process air circuit (3) and/or steam condensate from said steam engine (20).

8. Laundry dryer (1) according to any of the preceding claims, wherein said additional input (42, 50) to said siphonic trap (41) is located at the uppermost area of the downstream side of said siphonic trap (41), in particular at the convex surface of the inverted U-shaped portion of S-shaped siphonic trap (41).

9. Laundry dryer (1) according to any of the preceding claims, wherein said siphonic trap (41) is an S-shaped siphonic trap (41) and said additional input (42, 50) to said siphonic trap (41) is located on a median plane (45) of the inverted U-shaped portion of said siphonic trap (41) but is asymmetric with respect to said median plane (45) of said inverted U-shaped portion of said siphonic trap (41).

10. Laundry dryer (1) according to claim 9, wherein said additional input (42, 50) of said siphonic trap (41) is displaced towards the outlet branch (46) of said siphonic trap (41) such that the percentage of liquid flowing towards said siphonic trap (41) is up to 50% but not including 50%, and preferably up to 20%.

11. Laundry dryer (1) according to any of the preceding claims, wherein a joint (70) for connecting a duct (17) to said additional input (42, 50, 51, 52) is formed in one piece with said siphonic trap (41).

12. Laundry dryer (1) according to any of the preceding claims, wherein said dryer (1) comprises a self-standing body (71) and optionally a joint (70), said self-standing body (71) comprising said siphonic trap (41), said joint (70) being used for connecting a conduit (17) to said additional input (42, 50, 51, 52).

13. Method for operating a laundry dryer (1) with steam function according to any of the preceding claims, comprising forming a liquid plug (44) in the siphonic trap (41) by:

a1) a drying procedure is carried out in such a way that,

a2) collecting condensed moisture from the laundry being dried during said drying program, an

a3) Inputting a portion of the collected condensed moisture to the siphonic trap (41),

and/or by:

b1) a liquid, in particular water or a water-based solution, is preferably manually input into the steam engine liquid tank (21) of the steam engine (20) by means of a manual loading unit (29) of the steam engine liquid tank (21), and

b2) deflecting a portion of the manually inputted liquid to the siphonic trap (41).

14. The method according to claim 13, further comprising recirculating within said dryer (1) said condensed moisture formed during a laundry drying process and steam condensate which may be formed during a steam process, and further comprising deflecting a portion of the recirculated liquid towards said siphonic trap (41) to form a liquid plug (44) within said siphonic trap (41).

15. The method according to any one of claims 13 to 14, further comprising obtaining the liquid for forming the liquid plug (44) by:

receiving liquid manually input by the user, and/or

Collect overflow liquid from one or more of:

a steamer liquid tank (21),

-a manual loading unit (29) of the steamer liquid tank (21), and

-a removable tank (14) of said recirculation circuit.

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