CN116497577A

CN116497577A - Dryer with improved air tightness of process air circuit and corresponding operating method

Info

Publication number: CN116497577A
Application number: CN202310062660.1A
Authority: CN
Inventors: M·巴兰; O·德斯庞; B·克勒
Original assignee: BSH Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2022-01-26
Filing date: 2023-01-18
Publication date: 2023-07-28
Also published as: EP4219823A1

Abstract

The invention relates to a dryer, comprising a drum and a process air circuit, the process air circuit comprising: a blower for driving the process air; condensing means for condensing moisture in the process air from the drum; a condensed water collecting container; a condensate tank for receiving water diverted from the condensate collection vessel; an overflow container for placing a condensate tank; an electric pump unit for pumping the water in the condensed water collecting container to the condensed water tank; a pump conduit fluidly connecting the pump outlet with the inlet of the condensate tank; an overflow conduit fluidly connecting the overflow vessel with the condensate collection vessel; and a siphon located in the pump conduit and/or the overflow conduit to restrict the transfer of air through the conduits, the pump conduit and the overflow conduit being adapted to direct at least a portion of the water transferred from the condensate collection reservoir to the condensate tank back to the condensate collection reservoir without entering the condensate tank, the overflow siphon being located in the overflow conduit. The invention also relates to a method of operation for a dryer.

Description

Dryer with improved air tightness of process air circuit and corresponding operating method

Technical Field

The present invention relates to a dryer having improved air tightness of a process air circuit and an operating method for the dryer. The invention relates in particular to a dryer comprising a drum for receiving laundry to be dried and a process air circuit for passing process air through the drum, the process air circuit comprising: a blower for driving the process air; condensing means for condensing moisture from the process air from the drum; a condensed water collecting container; a condensate tank for receiving water diverted from the condensate collection vessel; an overflow container for placing a condensate tank; an electric pump unit associated with the condensate collection vessel for pumping water from the condensate collection vessel into the condensate tank; a pump conduit fluidly connecting the pump outlet and the condensate tank inlet; an overflow conduit fluidly connecting the overflow vessel and the condensate collection vessel; and a siphoning element in the pump conduit and/or the overflow conduit to limit the transfer of air through these conduits. The invention also relates to a method of operating the dryer.

Background

The known condensation dryer has a drum rotatably mounted in a housing, a fan for generating a flow of process air through the drum, and a condensation device comprising a collecting container for collecting condensed water accumulated during drying, and furthermore has a condensation water tank connected to the collecting container by a pipe, which is arranged in a tank connected to the collecting container by a drain pipe. In this case, the condensate in the collecting vessel is pumped to the condensate tank, typically by a pump. The condensate tank is located in the tank with a drain pipe leading to the collection vessel. This allows condensed water leaking from the condensed water tank to be discharged into the collecting container. However, the process air flow is connected to the environment through a drain pipe, and thus, the indoor air is sucked into the process air that has been dried. If there is an overpressure in the condenser area, some process air from the dryer will enter the room. This may result in reduced dryer efficiency and/or increased indoor air humidity in the dryer mounting chamber.

EP 2,141,279 A1 discloses a condensing drum dryer comprising a drum rotatably mounted in a housing, a fan for generating a flow of process air which is supplied to the drum and passed through a condensing device comprising a receiving container for receiving condensed water generated during drying and a collecting container connected to the receiving container by a pipe, the collecting container being arranged in a water tank which is connected to the receiving container by a discharge opening. The discharge opening has a valve which closes the connection from the receiving container to the discharge opening at least in an almost completely closed manner and which can open the connection to the receiving container by means of liquid flowing through the discharge pipe, which valve comprises a separate valve chamber which is separate from the receiving container and comprises an inlet and an outlet, in which valve chamber a movable closing member is arranged for opening or closing the inlet and/or the outlet, wherein the inlet is arranged at the bottom of the valve chamber such that the closing member can be moved from an inactive position to an open position by liquid flowing into the valve chamber. In one embodiment of the condensing tumble dryer, the valve is spatially proximate or mounted directly on or within the receiving container. In another embodiment, the vent is closed by the valve when the valve is in the inactive position.

EP 2,450,615 A1 discloses a dryer comprising: a housing having a bottom; a laundry compartment adapted to receive laundry to be dried; a process air circuit for circulating process air to the laundry compartment; condensing means for removing moisture from process air of said laundry compartment located in the process air circuit; a water collection tank for collecting the moisture condensed by the condensing means; a condensate tank unit for collecting moisture transferred from the header tank; a pump unit associated with the header tank for removing water therefrom and pumping it to a condensate tank unit; a first conduit fluidly connecting an outlet of the pump unit with an inlet of the condensate tank unit; and a second duct fluidly connecting the condensate tank unit with an inlet disposed at the bottom, the dryer further comprising a siphon-like element located in the first and/or second duct to restrict the transfer of air through the first and/or second duct. In one embodiment, a siphon-like element is located at one end of the first and/or second conduit. Preferably, the siphoning element is located at the end of the first conduit comprising the outlet of the pump unit and/or at the end of the second conduit comprising the inlet. Further, a dryer is disclosed wherein the first and/or second conduit comprises a hose connecting the pump unit outlet with the condensate tank inlet and/or connecting the condensate tank outlet with an inlet arranged at the bottom. The siphon element preferably comprises an S-bend hose portion.

Solutions for siphons and overflow siphons at the pump outlet are known. The known overflow siphon fills only when the overflow system is started, and may always leak if the customer clears the condensate reservoir after each cycle.

Disclosure of Invention

In view of this situation, it is an object of the present invention to provide a dryer with an improved process air circuit, the tightness of which is improved. A dryer should be provided in which a barrier is formed between an under-pressure inside the dryer and the atmospheric pressure of the surrounding environment. Preferably, the overall operation efficiency of the dryer should be improved. Another object is to provide a method of operation for such a dryer.

According to the invention, this object is achieved by a dryer and a method of operating the same according to the independent claims. Preferred embodiments of the dryer according to the invention are particularly shown in the dependent claims. The preferred embodiments of the method of operation correspond to the preferred embodiments of the dryer and vice versa, even if not explicitly stated herein.

Accordingly, the present invention relates to a dryer comprising a drum for receiving laundry to be dried and a process air circuit for passing process air through the drum, the process air circuit comprising: a blower for driving the process air; condensing means for condensing moisture in the process air from the drum; a condensed water collecting container; a condensate tank for receiving water diverted from the condensate collection vessel; an overflow container in which the condensate tank is placed; an electric pump unit associated with the condensate collection vessel, the electric pump unit for pumping water in the condensate collection vessel to the condensate tank; a pump conduit fluidly connecting the pump outlet with the inlet of the condensate tank; an overflow conduit fluidly connecting the overflow vessel with the condensate collection vessel; and a siphon located in the pump conduit and/or the overflow conduit to limit the transfer of air through the conduits, the pump conduit and the overflow conduit being adapted to direct at least a portion of the water transferred from the condensate collection reservoir to the condensate tank back to the condensate collection reservoir without entering the condensate tank, the overflow siphon being located in the overflow conduit.

In a preferred embodiment of the dryer, the pump conduit of the overflow container branches off from the pump conduit at a branching point, directly into the overflow container, i.e. not into the condensate tank. Preferably, a pump line closure is arranged in the pump line between the branching point and the condensate tank.

In another preferred embodiment of the dryer, the dryer comprises a direct bypass duct, which connects the pump duct and the overflow duct directly. Preferably the bypass conduit inlet point is located between the pump siphon and the condensate tank. It is also preferred that a direct bypass closure is provided between the bypass conduit inlet point and the bypass conduit outlet point. In this way the flow of water through the direct bypass conduit can be regulated.

Generally, a dryer is preferred in which a condensate collection container level sensor is provided in the condensate collection container. It is also preferable that a condensate tank water level sensor is provided in the condensate tank.

The use of the invention in a condensation dryer with a heat pump for generating a process air flow is particularly advantageous, since in this case the process air circuit must be particularly well insulated from the room air in order to achieve good efficiency or to release low levels of moisture to the room air.

In another preferred embodiment, the dryer includes a heat pump circuit including a refrigerant passage for circulating a refrigerant, a condenser as a heat source, an evaporator as a radiator, an expansion device for expanding the refrigerant, and a compressor for driving and compressing the refrigerant, the refrigerant being circulated through the compressor, the condenser, the expansion device, and the evaporator in this order. The condenser serves to heat the process air flow before it enters the drum as a drying chamber, while the evaporator serves to cool the air flow after it leaves the drying chamber.

The overflow conduit has an overflow siphon which closes off the overflow conduit and the condensate collection vessel in at least one almost airtight manner. The overflow siphon thus isolates the condensate collection reservoir from the external pressure of the installation space, which is in communication with the process air, wherein negative or positive pressure prevails.

In the present invention, a dryer including a pump siphon and an overflow siphon is more preferable.

The dryer may be a separate dryer or a washing dryer, which combines a laundry washing function with a drying function. The dryer of the present invention is preferably implemented as a laundry dryer.

In the present invention, a condensate collecting container is used to collect condensate generated during drying, and the condensate is pumped into a condensate tank through a pump conduit (typically a hose) by an electric pump unit. The condensate tank is placed in an overflow container, which is usually connected to the condensate collection container by means of an overflow conduit consisting of a pipe or hose. The overflow pipe is provided with an overflow siphon pipe.

The condensed water collecting container is, for example, an open-top tray, which is disposed below the condensing unit, so that condensed water generated in the condensing unit can be collected. In order to prevent secondary air from entering the process air flow, an overflow siphon is present between the overflow conduit and the condensate collection reservoir, preventing secondary air from entering the process air flow from the drain when the overflow siphon is filled with water.

For example, if the dryer of the present invention is equipped with a heat pump including a compressor, a heat exchanger and a pipe for refrigerant, no secondary air can enter the condenser area through the condensate collection vessel or overflow conduit if the blower creates a negative pressure during the drying operation.

The process air circuit comprises condensing means for removing moisture from the process air from the laundry compartment (i.e. drum). The condensed water formed in the condensing means is collected in a condensed water collecting container, which is preferably located in the bottom of the dryer. The water in the condensate collection container is then conveyed into a condensate tank, which is preferably arranged in the upper part of the dryer, so that the user can conveniently empty it periodically. The condensate tank is preferably in the form of a drawer slidably arranged in the above-mentioned upper part of the dryer. In order to convey water from the condensate collection container to the condensate tank, an electric pump unit is provided on the condensate collection container. The electric pump unit is preferably activated in accordance with the water level in the condensate collection container. For this purpose, as an example, a level sensor may also be provided on the condensate collection container.

When the condensate tank is full, the overflow receptacle allows water in the condensate tank to be transferred to the condensate collection receptacle. The electric pump unit is advantageously placed in a substantially closed environment. However, a closed environment may cause a pressure differential between the different volumes within the dryer, which in turn may cause air to flow from the condensate tank to the pump unit through a transfer conduit, i.e., a pump conduit, or from the condensate tank to the condensate collection vessel through an overflow conduit (or vice versa).

The overflow siphon and the pump siphon, if present in the dryer, limit the transfer of air through the overflow duct and the pump duct, respectively.

Advantageously, these conduits are realized in a simple manner by means of hoses. Preferably, the siphon tube comprises an S-bend hose portion. Advantageously, the siphon does not require additional elements to be produced and mounted on the dryer, the siphon produced by the S-twist of the hose being suitable for the intended purpose.

The dryer may be a front-loading dryer, which means that the axis of the drum, where the laundry is located, is positioned in a horizontal manner or is slightly inclined with respect to the horizontal plane, or a top dryer, where the axis of the drum is substantially vertical. In a preferred embodiment, the dryer is a front-loading laundry dryer.

A process air circuit, in particular a closed loop circuit, comprises a process air duct for guiding an air flow for drying laundry in the drum. The two opposite ends of the process air circuit are connected to the drum. More specifically, the hot dry air is fed into the drying chamber, flows over the laundry, and the moist (and cooled at a lower temperature) air thus produced also flows out of the drying chamber. In the case of a closed-loop drying air circuit, the moist process air is fed into a condensing device, i.e. a heat exchanger. In a preferred embodiment of the invention, the moist air is fed to an evaporator of a heat pump system, where the moist process air is further cooled and the moisture therein is condensed. The resulting cool dry air is then heated before re-entering the drum by means of a condenser or the like of the heat pump system, and the whole cycle is repeated until the drying process is completed. However, the dehumidified air may be discharged to the outside of the dryer. Alternatively or additionally, an air-air type heat exchanger may be used in order to remove moisture from the humid air stream leaving the drum. Such heat exchangers typically receive ambient air as a coolant to cool and remove moisture from the humid air stream passing therethrough. The process air may be heated by an electrical heating device or a gas driven heating device prior to entering the drum. The heated air flows through and over the damp laundry in the drum, thereby removing the humidity of the laundry. Thus, the condensing device is placed in the process air circuit.

If the dryer includes a heat pump circuit, a refrigerant is circulated to be cyclically compressed and expanded and cooled and heated in order to absorb heat in an evaporator by evaporating the refrigerant at a low pressure and to release heat by condensing the refrigerant at a high pressure. According to a preferred embodiment of such a dryer, the dryer comprises control means for controlling the operation of the dryer, wherein the expansion means is a variable valve operatively connected to the control means. This operation may be on-off, i.e. the valve switches between an open position for recirculating part of the refrigerant and a closed position for shutting off any recirculation. Alternatively, such operation may allow for varying the amount of refrigerant recirculated, either stepwise or continuously.

The overflow container may receive water from the condensate tank when the condensate tank becomes full or the water therein reaches a certain level. Preferably, the condensate tank comprises a first aperture on one side of the condensate tank, the first aperture being located at a given level, whereby if the water level in the condensate tank rises above the given level, the water falls into the overflow receptacle. In this way, the condensate tank is always filled to or below a predetermined maximum level. Any additional water pumped by the pump unit to the condensate tank will overflow from the openings and fall into the overflow receptacle.

In order to avoid air exchange, a siphon is provided at least in the overflow conduit, preferably also in the pump conduit. The location of the siphon may be anywhere along the pipes. The presence of the siphon tube also maintains a certain amount of water in each conduit when the pump unit is not operating or water is not dripping from the condensate tank to the condensate collection vessel, avoiding or reducing the likelihood of air passing through the conduit. The pressure differential may be maintained.

The dryer generally includes a control unit for operation of the dryer.

The invention also relates to a method of operation for a dryer comprising a drum for receiving laundry to be dried and a process air circuit for passing process air through the drum, the process air circuit comprising: a blower for driving the process air; condensing means for condensing moisture in the process air from the drum; a condensed water collecting container; a condensate tank for receiving water diverted from the condensate collection vessel; an overflow container in which the condensate tank is placed; an electric pump unit associated with the condensate collection vessel, the electric pump unit for pumping water in the condensate collection vessel to the condensate tank; a pump conduit fluidly connecting the pump outlet with the inlet of the condensate tank; an overflow conduit fluidly connecting the overflow vessel with the condensate collection vessel; and a siphon located in the pump conduit and/or the overflow conduit to limit the transfer of air through the conduits, the pump conduit and the overflow conduit being adapted to direct at least a portion of the water transferred from the condensate collection reservoir to the condensate tank back to the condensate collection reservoir without entering the condensate tank, the overflow siphon being located in the overflow conduit, the method of operation comprising the steps of:

(a) Starting a drying process by starting rotation of the blower, the heating device and the drum;

(b) When the water level H in the condensed water collecting container ^ccv Up to a set height H _set1 ^ccv Starting the electric pump unit;

(c) Pumping water in the condensed water collecting container to the direction of the condensed water tank through a pump conduit;

(d) Checking the height H of the water in the condensate tank ^ct Whether or not to exceed a preset value H _set2 ^ct The method comprises the steps of carrying out a first treatment on the surface of the And

(e) If H ^ct >H _set2 ^ct At least a portion of the water delivered from the condensate collection vessel to the condensate tank is directed back to the condensate collection vessel without entering the condensate tank.

In a preferred embodiment of the method of operation of the present invention, in the dryer, the overflow vessel pump conduit branches from the pump conduit at a branching point directly into the overflow vessel, the method of operation further comprising step (f):

(f) If H ^ct >H _set2 ^ct At least a portion of the water pumped from the condensate reservoir is pumped directly from the pump conduit into the overflow reservoir.

In a further preferred method of operation, a pump conduit closure device is provided in the pump conduit between the branching point and the condensate tank, the method of operation comprising the additional step (g):

(g) If H ^ct >H _set2 ^ct The pump conduit closure device is closed.

Finally, a method of operation is preferred wherein the dryer comprises a direct bypass conduit directly connecting the pump conduit and the overflow conduit, the method of operation comprising the additional step (f'):

(f') if H ^ct >H _set2 ^ct At least a portion of the water pumped from the condensate reservoir is pumped from the pump conduit into the direct bypass conduit directly into the overflow reservoir.

The present invention provides a number of advantages. Advantages of the present invention include improving dryer performance by providing a dryer with improved process air circuit tightness. The invention in this respect employs simple, inexpensive and fast assembly means. In the drying process, the energy consumption is reduced. Since the tightness of the process air flow is now very good, the effect of the process air flow is improved or optimized.

The present invention can establish an effective barrier between the under-pressure inside the dryer and the atmospheric pressure of the surrounding environment. This not only allows the pre-addition of water when the condensate pump is first started, but also ensures that the tightness is maintained when the condensate pump is stopped. In any way, the process air circuit may remain airtight. The overflow siphon is filled the first time the condensate pump is started and refilled each time the condensate pump is cycled to maintain air tightness. Sealing the process air pressure from the atmospheric pressure of the dryer may allow the dryer to achieve better performance.

Drawings

Fig. 1 to 3 show non-limiting examples of dryers according to the invention or components that contribute to the technology of the invention, wherein corresponding components are identified by the same reference numerals.

Fig. 1 shows a condensation dryer in vertical section according to a first embodiment, wherein a water container, here called condensate water collecting container, is provided for collecting condensate water from an evaporator, which is used here as a condensing device, and which container is equipped with an electric pump and electrodes for detecting the water level;

fig. 2 shows important parts related to the core of the present invention, namely, parts for treating condensed water generated in a dryer, the airtightness of which is ensured, according to a second embodiment of the present invention;

fig. 3 shows the important parts related to the core of the present invention according to the first embodiment of the present invention shown in fig. 1, namely, parts for treating condensed water generated in a dryer, the air tightness of which is ensured.

Detailed Description

Fig. 1 shows a condensation dryer 1 (hereinafter abbreviated as "dryer") according to a first embodiment in vertical section, in which condensed water 22 from an evaporator 18 of a heat pump is provided with a condensed water collecting container 5, and the condensed water collecting container 5 is equipped with an electric pump unit 7.

The dryer shown in fig. 1 shows a drum 2 as a drying chamber, which can rotate around a horizontal axis. Inside the drum, a tappet 14 is fixed in order to move laundry (not shown here) during rotation of the drum 2. The electric heating device 13 is here used to heat the air flow, and the heat pumps 18, 19, 20, 11 and the blower 12 are arranged in the process air circuit 3. The warm process air is thus fed to the drum 2, cooled after passing through the drum 2, and heated again after the moisture contained in the process air condenses. The heated process air enters the drum 2 from behind, i.e. from the side of the drum 2 opposite the access door 17, through its perforated floor, comes into contact with the laundry to be dried, and flows through the opening of the filling drum 2 to the lint filter 21 in the access door 17, which closes the opening of the filling dryer 1. Thereafter, the air flow in the access door 17 is led downwards and moves in the process air circuit 3 to the evaporator 18. There, the moisture absorbed from the laundry is condensed due to cooling, and the condensed water is collected by the condensed water collecting container 5. The condensate is pumped by means of an electric water pump unit 7 to a condensate tank 6, which is placed in an overflow container 8. The overflow container 8 is connected to the condensate collection container 5 via an overflow conduit 10. A pump siphon 23 is placed in the pump conduit 9 and a overflow siphon 24 is placed in the overflow conduit 10 to limit the transfer of air through the pump conduit and the overflow conduit.

In this non-limiting embodiment, the pump conduit 9 and the overflow conduit 10 are adapted to direct at least a portion of the water 22 delivered from the condensate collection container 5 to the condensate collection container 6 back to the condensate collection container 5 without entering the condensate collection container 6.

In the particular embodiment shown in fig. 1, a direct bypass conduit 26 is provided, which connects the pump conduit 9 and the overflow conduit 10 directly. Although not visible in fig. 1, the direct bypass conduit inlet point of the bypass conduit 26 is located between the overflow siphon 24 and the condensate tank 6. 23 refers to a pump siphon located in the pump conduit 9. Although not shown here, the conduit closure device is located between the direct bypass conduit entry point and the direct bypass conduit exit point.

In the embodiment of the dryer of the present invention shown in fig. 1, a first water level sensor is provided in the condensate collection container, and a second water level sensor is provided in the condensate tank 6. However, these two water level sensors cannot be seen in fig. 1.

After the evaporator 18, the process air is again fed to the electric heating device 13 by the blower 12. However, the process air is also heated by the condenser 19 of the heat pump 38, 18, 19, 20, 11.

The control of the dryer 1 is achieved by the control unit 4, which can be adjusted by a user through the operation panel 15.

In the heat pumps 38, 18, 19, 20, 11 of the present embodiment, the refrigerant is evaporated in the evaporator 18, compressed in the compressor 11, here a variable power compressor, and then condensed in the condenser 19. 20 is a throttle valve.

The process air is fed into the drum 2 in the process air circuit 3 by means of a blower 12. After passing through the drum 2, the moist, warm process air is led to the evaporator 18 of the heat pump 38, 18, 19, 20, 11, which also has a variable speed compressor 11, a throttle valve 20 and a condenser 19. The arrows shown in fig. 1 represent the flow direction of the coolant in the heat pump and the air in the process air circuit.

After the refrigerant of the heat pumps 38, 18, 19, 20, 11 evaporates in the evaporator 18, it is led to the condenser 19 by the speed-dependent compressor 11. In the condenser 19, the refrigerant liquefies, releasing heat to the process air flowing in the process air circuit 3. The now liquid refrigerant is again fed to the evaporator 18 through the throttle 20, thereby closing the refrigerant circuit. In the present embodiment, a temperature sensor S between the evaporator 18 and the compressor 11 ^T _WPK 28 measures the temperature T of the refrigerant.

In the embodiment shown in fig. 1, the electric heating device 13 serves to heat the process air more rapidly. In other embodiments of the invention, the electric heating device 13 may be omitted.

The optical/acoustic indication means 16 allow a user of the dryer to display, for example, the operating parameters and/or the expected duration of the drying process.

In the operating method according to the invention, the process air is recirculated through the process air circuit 3 until preferably the desired degree of dryness of the laundry is reached.

The dryer 1 of fig. 1 also achieves an accurate control of the operation of the heat pump, whereby the drying phase can be effectively controlled by adjusting the blower 12 and the compressor 11 by the control unit 4 so that the temperature of the process air does not exceed a predetermined maximum temperature T _max 。

Fig. 2 shows an important part related to the core of the present invention, namely, a part for treating condensed water generated in a dryer, of which air tightness is ensured, according to a second embodiment of the present invention.

Condensed water produced when the humid air of the process air circuit (not shown here) is cooled by a condensing means, i.e. a heat exchanger (also not shown here), is collected in the condensed water collecting container 5. The electric pump unit 7 is placed in the condensed water collecting container 5 so that condensed water, i.e., water 22, is pumped away. The water level sensor, the so-called condensate collection vessel water level sensor 34, senses that condensate 22 should be pumped away when the water level reaches a prescribed level. The condensate 22 is pumped out through the pump conduit 9, in which a siphon 23 is placed in a direction towards the condensate tank 6, which is placed in the overflow receptacle 8. The pump conduit 9 and the overflow conduit 10, in which a siphon is also provided, are adapted to guide at least a portion of the water 22 delivered from the condensate collection reservoir 5 to the condensate collection reservoir 6 back to the condensate collection reservoir 5 without entering the condensate reservoir 6. An overflow siphon 24 is provided in the overflow conduit 10. The overflow conduit 10 is connected to the overflow vessel 8 at an outlet 33 of the overflow vessel 8.

In the second embodiment shown in fig. 2, the overflow vessel pump conduit 37 branches off from the pump conduit 9 at a branching point 27 directly into the overflow vessel 8. In this way, the condensate 22 may be prevented from entering the condensate tank 6 when the water level exceeds a predetermined height. In order to sense the water level, a so-called condensate tank water level sensor 29 is placed in the condensate tank.

In the dryer of fig. 2, the process of the present invention including the steps of:

(a) The drying process is started by starting the rotation of the blower, the heating means and the drum (all not shown here);

(b) When the water level H in the condensate collection vessel 5 ^ccv Up to a set height H _set1 ^ccv At that time, the electric pump unit 7 is started;

(c) Pumping water 22 in the condensate collection vessel 5 via a pump conduit 9 in the direction of the condensate tank 6;

(d) Checking the height H of the water in the condensate tank 6 ^ct Whether or not to exceed a preset value H _set2 ^ct The method comprises the steps of carrying out a first treatment on the surface of the And

(e) If H ^ct >H _set2 ^ct At least a portion of the water 22 delivered from the condensate collection vessel 5 to the condensate tank 6 is directed back to the condensate collection vessel 5 without entering the condensate tank 6.

In the dryer of fig. 2, i.e. in its second embodiment, step (f) may also be performed:

(f) If H ^ct >H _set2 ^ct At least a part of the water 22 pumped out of the condensate reservoir 5 is pumped from the pump conduit 9 directly into the overflow reservoir (8).

A pump conduit closure device is disposed in the pump conduit between the branching point and the condensate tank, the method of operation comprising the additional step (g):

(g) If H ^ct >H _set2 ^ct The pump conduit closure device 30 is closed.

In fig. 2, the pump siphon 23 is located between the pump outlet 35 and the condensate tank inlet 36, in particular between the pump outlet 35 and the branch point 27 in the second embodiment.

The first embodiment differs from the second embodiment in that no branch of the pump conduit 9 is here directly connected to the overflow vessel 8. Instead, the dryer comprises a direct bypass conduit 26, which connects the pump conduit 9 and the overflow conduit 10 directly. In this way, condensate 22 from the condensate collection vessel 5 may flow directly back to the condensate collection vessel 5 through the direct bypass conduit 26 without entering the condensate tank 6. In order to control the flow through the direct bypass conduit 26, a so-called direct bypass closure 25 is provided therein. In particular, the direct bypass closure 25 is located between the bypass conduit inlet point 31 and the bypass conduit outlet point 32.

In the first embodiment shown in fig. 3, the bypass conduit inlet point 31 is located between the pump siphon 23 and the condensate tank 6.

Reference signs not explicitly mentioned in fig. 3 have the same meaning as in fig. 2.

List of reference numerals

1 dryer

2 roller

3 process air circuit

4 control unit

5 condensed water collecting container

6 condensing water tank

7 electric pump unit

8 overflow container

9 pump conduit

10 overflow conduit

11 (variable power) compressor

12 blower

13 electric heating device

14 roller rib for driving clothes, tappet

15 operation panel

16 optical/acoustic indicating device

17 access door

18 evaporator, condensing unit

19 condenser

20 throttle valve and expansion device

21 fluff filter

22 water

23 pump siphon

24 overflow siphon

25 direct bypass closure

26 direct bypass conduit

27 branch point

28 temperature sensor S in coolant loop ^T _WPK For measuring the temperature T of the coolant _K

29 condensing water tank water level sensor

30 pump conduit sealing device

31 bypass conduit entry point

32 bypass conduit exit point

33 overflow vessel outlet

34 condensed water collecting container water level sensor

35 pump outlet

36 condensate tank inlet

37 overflow container pump conduit

38 refrigerant channels

Claims

1. Dryer (1) comprising a drum (2) for receiving laundry to be dried and a process air circuit (3) for passing process air through the drum (2), the process air circuit (3) comprising: a blower (12) for driving the process air; condensing means (18) for condensing moisture in the process air from the drum (2); a condensed water collection container (5); a condensate tank (6) for receiving water (22) diverted from the condensate collection vessel (5); -an overflow container (8) in which the condensate tank (6) is placed; -an electric pump unit (7) associated with the condensate collection container (5) for pumping water (22) in the condensate collection container (5) to the condensate tank (6); a pump conduit (9) fluidly connecting a pump outlet (35) with an inlet (36) of the condensate tank; an overflow conduit (10) fluidly connecting the overflow container (8) with the condensate collection container (5); and a siphon (23, 24) in the pump conduit (9) and/or the overflow conduit (10) to limit the transfer of air through the pump conduit (9) and the overflow conduit (10), characterized in that the pump conduit (9) and the overflow conduit (10) are adapted to direct at least a portion of the water (22) transferred from the condensate collection container (5) to the condensate tank (6) back to the condensate collection container (5) without entering the condensate tank (6), the overflow siphon (24) being located in the overflow conduit (10).

2. Dryer (1) according to claim 1, wherein an overflow vessel pump conduit (37) branches off from the pump conduit (9) at a branching point (27) to directly enter the overflow vessel (8).

3. Dryer (1) according to claim 2, wherein a pump conduit closure device (30) is placed in the pump conduit (9) between the branching point (27) and the condensate tank (6).

4. Dryer (1) according to claim 1, wherein the dryer comprises a direct bypass duct (26) directly connecting the pump duct (9) and the overflow duct (10).

5. Dryer (1) according to claim 4, wherein a bypass conduit inlet point (31) is located between the pump siphon (23) and the condensate tank (6).

6. Dryer (1) according to claim 4 or 5, wherein the direct bypass shut-off device (25) is located between the bypass duct inlet point (31) and the bypass duct outlet point (32).

7. Dryer (1) according to any one of claims 1 to 6, wherein a condensate collection container level sensor (34) is provided in the condensate collection container (5).

8. Dryer (1) according to any one of claims 1 to 7, wherein a condensate tank water level sensor (29) is provided in the condensate tank (6).

9. Dryer (1) according to any one of claims 1 to 8, wherein the dryer (1) comprises a heat pump circuit comprising a refrigerant channel (38) for circulating a refrigerant, a condenser (19) as a heat source, an evaporator (18) as a radiator, an expansion device (20) for expanding the refrigerant and a compressor (11) for driving and compressing the refrigerant, the refrigerant being circulated through the compressor (11), the condenser (19), the expansion device (20) and the evaporator (18) in this order.

10. Dryer (1) according to any one of the preceding claims, wherein the dryer comprises a pump siphon (23) and an overflow siphon (24).

11. Dryer (1) according to any one of the preceding claims, wherein said dryer (1) is implemented as a laundry dryer.

12. A method of operation for a dryer (1) comprising a drum (2) for receiving laundry to be dried and a process air circuit (3) for passing process air through the drum (2), the process air circuit (3) comprising: a blower (12) for driving the process air; condensing means (18) for condensing moisture in the process air from the drum (2); a condensed water collection container (5); a condensate tank (6) for receiving water (22) diverted from the condensate collection vessel (5); -an overflow container (8) in which the condensate tank (6) is placed; -an electric pump unit (7) associated with the condensate collection container (5) for pumping water (22) in the condensate collection container (5) to the condensate tank (6); a pump conduit (9) fluidly connecting a pump outlet (35) with an inlet (36) of the condensate tank; an overflow conduit (10) fluidly connecting the overflow container (8) with the condensate collection container (5); and a siphon (23, 24) located in the pump conduit (9) and/or the overflow conduit (10) to limit the transfer of air through the pump conduit (9) and the overflow conduit (10), wherein the pump conduit (9) and the overflow conduit (10) are adapted to direct at least a portion of the water (22) delivered from the condensate collection container (5) to the condensate collection container (6) back to the condensate collection container (5) without entering the condensate collection container (6), an overflow siphon (24) being located in the overflow conduit (10), the method of operation comprising the steps of:

(a) Starting a drying process by starting the rotation of the blower (12), the heating device (13) and the drum (2);

(b) When the water level H in the condensed water collecting container (5) ^ccv Up to a set height H _set1 ^ccv Starting the electric pump unit (7);

(c) Pumping water (22) in the condensed water collecting container (5) to the direction of the condensed water tank (6) through a pump conduit (9);

(d) Checking the height H of water in the condensate tank (6) ^ct Whether or not to exceed a preset value H _set2 ^ct The method comprises the steps of carrying out a first treatment on the surface of the And

(e) If H ^ct >H _set2 ^ct At least a portion of the water (22) delivered from the condensate collection vessel (5) to the condensate tank (6) is directed back to the condensate collection vessel (5) without entering the condensate tank (6).

13. The operating method according to claim 12, wherein in the dryer (1) an overflow vessel pump conduit (37) branches off from the pump conduit (9) at a branching point (27) to directly enter the overflow vessel (8), the operating method further comprising step (f):

(f) If H ^ct >H _set2 ^ct At least a part of the water (22) pumped out of the condensate reservoir (5) is pumped directly from the pump conduit (9) into the overflow reservoir (8).

14. Method of operation according to claim 13, wherein a pump conduit closure device (30) is placed in the pump conduit (9) between the branching point (27) and the condensate tank (6), the method of operation comprising the additional step (g):

(g) If H ^ct >H _set2 ^ct The pump conduit closure device (30) is closed.

15. Method of operation according to claim 12, wherein the dryer (1) comprises a direct bypass duct (26) directly connecting the pump duct (9) and the overflow duct (10), the method of operation comprising the additional step (f'):

(f') if H ^ct >H _set2 ^ct At least a part of the water pumped out of the condensate reservoir (5) is pumped from the pump conduit (9) into said direct bypass conduit (26) directly into the overflow reservoir (8).