EP2609245A2

EP2609245A2 - Method for drying textiles and laundry dryer

Info

Publication number: EP2609245A2
Application number: EP11741228.8A
Authority: EP
Inventors: Jochen Ganz
Original assignee: innostarter AG
Current assignee: QUO AG
Priority date: 2010-08-24
Filing date: 2011-08-09
Publication date: 2013-07-03
Anticipated expiration: 2031-08-09
Also published as: EP2609245B1; CH703623A1; WO2012025378A3; WO2012025378A2

Abstract

In a method for drying textiles in a receptacle provided therefor, the pressure in the receptacle (1) containing the textiles (11) to be dried is lowered below the ambient pressure. The evaporation temperature is reduced accordingly, and the evaporated moisture is extracted from the interior of the receptacle. The evaporated and extracted moisture is heated to the ambient pressure by compression using a turbo compressor (3), and at least some of the heated moisture is delivered to the outer wall of the receptacle, where at least some of the moisture condenses to heat the receptacle.

Description

Process for drying textile good

The present invention relates to a method for

Drying textile goods according to the preamble of claim 1, a method of operating a clothes dryer and a tumble dryer.

In view of the continuous in recent years

The increasing relevance of environmental and energy policy issues and increased energy awareness on the part of the population today is the energy efficiency of

Electrical appliances are very important too. As a significant proportion of the energy produced in the industrialized countries is spent on drying clothes, many development efforts have also been concentrated on the

Improvement of the efficiency of tumble dryers.

Thus, e.g. Dryers are known in which the pressure in the laundry containers is reduced, so that the moisture evaporates already at a relatively low temperature and consequently the energy consumption is reduced. Such clothes dryers are e.g. from documents DE 1 432 869, DE 1 585 916, US Pat. No. 3,030,712 and US Pat. No. 3,238,750.

A disadvantage of these clothes dryers is in particular that they still have a relatively low efficiency and a relatively complex structure. DE 2 218 440 proposes a tumble dryer in which the pressure in

Laundry container reduced and is performed as an additional measure to increase the efficiency of the air flow to dry the laundry through the heat exchanger of a heat pump in a circuit. Another disadvantage is that the Device has a relatively complicated structure and a relatively low efficiency.

In FR 1 201 674, DE 31 16 697 and DE 36 44 077 devices for dehumidifying wet laundry are again

proposed, in which the space containing the textile material is evacuated and the thus evaporated at low temperature moisture is removed. In addition, in the devices proposed in these publications, the withdrawn moisture is compressed, which thereby a

Temperature increase experiences. The elevated temperature and the condensation energy are in a heat exchanger

exploited to heat the material to be dried in the device. The placement of an additional heat exchanger has not been proven, which is why the proposed devices have never been further developed to production maturity.

In view of the above mentioned drawbacks has been in the

WO2007 / 093073 proposed a method for drying textile good or operating a tumble dryer, which is characterized by a higher efficiency compared to the prior art. reduced energy consumption

distinguishes.

It is proposed that for drying a textile material in a designated receptacle initially the interior of the receptacle is evacuated with the material entered therein and heated. By reducing the pressure and heating the moisture is evaporated from the material, whereupon the water is withdrawn from the interior. By discharging the withdrawn water to the environment or by compression of the withdrawn water to ambient pressure, this is heated and at least a portion of the energy of the water vapor we supplied to further heating of the drum on the outside, wherein the water vapor thereby at least partially condensed.

The object of the present invention is based on the mentioned WO2007 / 093073 to propose a further improvement in the operation of a tumble dryer.

These objects are achieved for a method by the features of the characterizing part, in particular of claim 1 and for the tumble dryer by the features of

characterizing part of claim 6.

According to the invention, it is proposed that the textile good to be dried be arranged in a receptacle provided for it, and that the pressure in the receptacle with the

Entered to be dried good compared to the

Ambient pressure by means of a turbo compressor (Fig.l ...) is reduced, whereby the evaporation temperature of the moisture in the good is reduced accordingly, whereupon the evaporated moisture is removed from the recording.

It is suggested that the pressure in the receptacle, such as a drying room and / or a

Washer drum, initially reduced and at least heated together with the material to be dried therein, that evaporates at reduced pressure, whereupon the evaporated moisture, preferably continuously, from the recording, such as the drying room and / or the laundry drum is deducted. The withdrawn moisture is different than in WO2007 / 093073 not with a conventional compressor / vacuum pump

Ambient pressure compressed, but by means of a

Turbo compressor.

Contrary to the solutions proposed in the prior art, the increased heat and the heat of condensation is not used via a separate heat exchanger, but

at least a portion of the heated moisture is applied directly to the outer wall of the receptacle, such as the

Dry space and / or the laundry drum supplied and condenses there at least partially, to these and

in particular, to heat the material arranged therein to be dried.

Turbocompressors are usually for very large

Flow rates suitable because an efficient machine high peripheral speeds are necessary, which means that for small machines very high speeds are required. Radial turbocompressors typically require a peripheral speed of 270m / s. This results in high pressure ratios (typically 2-3) with good efficiency (about 70%). Turbocompressors require a large

Volume flow in relation to the size, otherwise the gap losses destroy the efficiency. This means that the small volume flow results in extremely fast rotating machines, for which, until recently, there was no electric power

Drives or generators were available. However, one finds also in the previous technique very small

Radial turbomachinery. So in the cryotechnology as

Throttle element on expansion turbines and the

Exhaust gas turbocharger for piston engines. In both cases Speeds up to 300 '000 revolutions per minute usual. In all applications, the turbocompressor is connected via a

Turbine driven and not directly electric or

mechanically.

The limits of the use of direct electrical

driven turbomachinery are today at the speed of an electric motor or a generator. Until recently, the answer to the question of the feasibility of a direct-drive turbocompressor for here would have been

according to the invention clearly defined application with no

need to be answered. Today, electric motors are available that can be used up to 1'000'000 revolutions per minute. These are all without exception electronic, as brushes at the

Operating conditions are hard to imagine. This was made possible by fast and cost-effective

Power electronics, with which one is able to drive motors accordingly high frequency.

Due to the now recently possible dimensionally small turbocompressors can by the invention

proposed combination with a dryer a significant increase in efficiency will be possible, with

at the same time extremely compact construction, by the

Turbomachine latest generation dimensionally can be kept relatively small.

In conclusion, it follows that the use of a turbocompressor has to be considered as a key to that in a dryer, as proposed in the

WO2007 / 093073 a marked increase in efficiency at the same time at least constant sizing is made possible.

The invention has the advantage that due to the favorable energy balance of the process, the costs for the drying of the material to be dried, such as the laundry or the like, are reduced. The clothes dryer according to the invention also has the advantage of simplified compared to known clothes dryers

Construction, which contributes to the reduction of manufacturing costs. Another advantage is that tumble dryers can be operated more economically than known dryers.

In addition, the laundry is dried much more gently thanks to the lower drying temperature.

Essence of the invention is that from the laundry too

withdrawing water is used as a working medium for an open heat pump process.

The invention is based on

Embodiments with reference to the attached

Figures explained in more detail. Show it:

Fig. 1 shows a drum and adjacent thereto components

a laundry dryer according to the invention,

schematically in a section perpendicular to

Drum axis,

2 shows the drum and adjacent to this components of a laundry dryer according to the invention, schematically in a section along the drum axis, FIG. 3 impeller of a radial trolley compressor with and without cover disk, FIG.

Fig. 4 section along the shaft axis through a 2-stage turbocompressor with electric motor and storage, both compressor stages on the same

Shaft end are arranged,

5 section along the shaft axis through a two-stage turbocompressor with electric motor and storage, wherein the two compressor stages are each arranged at a shaft end,

Fig. 6 section along the shaft axis through a 2-stage turbo compressor with electric motor and storage, the two compressor stages are each arranged at a shaft end, wherein between the compressor stages, a heat exchanger as

Intercooler is arranged.

The arrangement shown schematically in Fig. 1, which comprises a drum 1 and to these adjacent components is inside a chassis (not shown) of the

Tumble dryer housed. The airtight

lockable drum 1 serves to accommodate e.g. from

Laundry and is of a for example cylindrical

Insulation housing 2 made of good thermal insulation material, such as insulation wool, polystyrene, foamed

Surrounded by polyurethane, etc. The drum 1 consists of a good heat-conducting material, such as stainless steel, aluminum, etc. Of course, both drum and insulation housing also spherical, egg-shaped, etc.

be formed, it is essential that the form resp. the Construction allows the evacuation of the interior. In the lower area, the insulation housing 2 is provided with a liquid, for example ball-shaped or cylindrical collecting vessel 5, for collection. At the

Tumble dryer is a (not shown)

Heater provided for heating the drum interior 4, wherein it is in the heater

For example, to a heating coil, as shown, or can be arranged at a distance from the drum 1 in the insulation housing infrared heat radiator. At the

Dryer may be provided a control device by means of which in a conventional manner by means of

addressed heating the temperature in the

Drum interior 4 can be controlled. In this case, the pressure in the drum, the so-called temperature indicator, as long as there is sufficient water or moisture in the system, such as the laundry, is present.

For the pressure reduction in the drum 4, as now proposed according to the invention, a turbocompressor 3 is provided which, for example, draws air-water-vapor mixture from the interior of the drum via a discharge line provided centrally in the drum axis. Subsequent to the turbo compressor is a return line. 9

provided to lead at least a portion of the compressed air-water vapor mixture into the interior of the insulating housing 2 to the outer wall of the drum 1.

Fig. 2 shows the drum 1 and adjacent thereto

Components of a tumble dryer according to the invention,

schematically in a section along the drum axis. The For example, cylindrical drum 1 is pressure-resistant and is rotatably supported by (not shown) means in a known manner in the insulating housing 2 and driven by a (not shown motor). As the access to the loading of the drum 1 or to remove laundry 11 from the drum 1 is done via a closable by the door 6 access opening, which is provided in the front region of the drum 1.

Between the drum 1 and the insulation housing 2

there remains a gap 7.

The following is the description of the drying process. At the beginning, a location-dependent external air pressure of approximately 1 bar prevails in the drum interior 4. After the

Drum interior 4 loaded with wet laundry 11 and the door 6 is closed, a temperature of, for example, 60 ° C is produced in the drum interior 4, in which the laundry is spared and, above all, does not shrink. At the same time, the interior space 4 is successively evacuated by means of the turbo-compressor 3 to a pressure of approximately 0.2 bar, whereby the vapor pressure of the moisture in the laundry is increased and evaporation of the moisture commences.

Subsequently, water vapor-air mixture, which contains steam evaporated from the laundry, from

Turbocompressor 3 from the drum interior 4 in the

Outside area A, which lies outside of the drum interior 4, promoted, the originating from the laundry

Moisture is removed from the drum interior 4. Since the drum 1 is largely hermetically sealed, the negative pressure during removal of the water vapor-air mixture in the drum interior 4 is maintained.

From physics is known that due to the pressure decrease without further heating of the drum interior 4 the

Temperature in the drum interior 4 fall and thus the evaporation intensity (for example, defined as

Amount of moisture that evaporates from the laundry per unit of time) would decrease or the evaporation would even come to a standstill. It could possibly come to the freezing of the water in the laundry. Therefore, it is necessary that during the drying process the drum interior 4 at least as much heat, for example by the

addressed heating device is supplied, that the evaporation process is kept in motion. The pumping of the water vapor-air mixture is carried out until the mentioned predetermined negative pressure of, for example, has reached almost 0.2 bar. It has been shown that a gentle and energy-efficient drying results if the temperature in the drum interior 4 during the pumping, for example, at 60 ° C holds constant and the pressure by pumping the water vapor-air mixture to about 0.2 bar reduced. For further details on the physical processes that take place during the drying process in the drum interior 4, reference is made to the technical literature.

As mentioned above, the pumped

Water vapor-air mixture to an outside area A fed, which is outside the drum interior 4 and in the atmospheric pressure prevails. Since during the pumping of the Water vapor-air mixture from the drum interior 4 is a pressure in the drum interior 4 is generated, which is less than the atmospheric pressure is compressed in an outdoor area A steam-air mixture in the outer area A and thereby heated by itself. In one possible embodiment of the method, at least part of the compressed and heated steam-air mixture is passed back into the intermediate region 7 within the insulating housing 2 and fed to the outside of the drum 1.

Due to the good thermal conductivity of the wall of the

Drum 1 is carried out a transfer of the heat of the water-steam mixture from the outside of the drum in the

Drum interior 4, so that the cooled in the interior in consequence of evacuation and evaporation of moisture cooled material is reheated. The amount of the at the

Outside guided water-steam mixture are chosen such that the previously mentioned and desired internal temperature of about 60 ° can be maintained.

Due to this cooling output to the drum 1 condenses, the outside of the drum 1 supplied water vapor. Thus, a heat recycling takes place, in which the drum 1 serves as a kind of heat exchanger. Thus, the further heating of the drum by the above-mentioned

Heating device or is an otherwise required

in addition to the drum 1 arranged heat exchanger

lapsed, causing the structural and operational

To reduce expenditure of erfxndungsgemässen drying device and thus their manufacturing and operating costs. By choosing a particularly good thermal insulation material for the insulation housing 2, the energy losses can be reduced and thus the efficiency of the

Improve drying process. The precipitated in the condensation water runs down along the outside of the drum 1 and finally enters the

Collection container 5.

The big advantage of the present invention, compared with the dryer as proposed in WO2007 / 093073, is the use of a turbo-compressor or a small turbo-compressor for generating the vacuum in the drying chamber. The use of the turbo-compressor brings a significant increase in efficiency of the dryer with at the same time reduced operating costs.

By enabling small turbocompressors, the dryer can also be dimensioned analogously to a dryer, as known in the art.

For example, proposed is a radial

Turbo compressor with at least 2 stages as shown in Fig. 4, 5 or 6, wherein the wheels with or without cover discs (Fig. 3) can be performed. One

Multi-stage turbocompressor with one or more

Coolers between the individual compressor stages (FIG. 6) can be energetically advantageous. The turbocompressor and the possible intercooler, for example, arranged so that they are in the condensation chamber (7) or at least give off their waste heat in this.

In the schematically shown in Figs. 1 to 6

Embodiments are of course only to possible embodiments, which can be modified in any way, modified or supplemented by other elements. In particular, the presentation of the itself was usually at

Dryers used additional units and housing parts omitted because they are best known analog conventional devices. Figs. 1 to 6 concentrate on the invention essential elements of

illustrated embodiments. In particular, the form of the drum shown in the figures

Of course, be changed as desired, depending on, for example, at which vacuum conditions and temperatures the drying device is to operate. Also the described operating conditions are only

For example, and it is of course possible to work at a lower or higher negative pressure, which of course also change the temperature conditions. It is also possible to move the drum with the moist, textile material or leave it alone, depending on whether a gentle drying is required.

Known, a large part of the damage to the laundry by the mechanical movement and less by the drying process itself. So it is for example possible for wool to provide a special drying process in which the drum is little or no move.

Preferred operating conditions result from the textile material to be dried in each case and the optimization of the drying device proposed according to the invention is not in itself an object of the present invention. In addition, it should be pointed out once again that instead of only one laundry drum as shown in FIGS. 1 and 2, an evacuated and heated drying room

may be provided, in which a rotatable

Laundry drum is arranged. The advantage . This solution could be that the evacuation of a stationary drying space is structurally simpler than the evacuation of a rotatable laundry drum.

Claims

Claims:

1. A method for drying a textile material in a designated receptacle, wherein the pressure in the

Recording (1) with the material to be dried (11) is reduced to the ambient pressure, whereby the

Evaporation temperature is reduced accordingly and the vaporized moisture is withdrawn from the interior of the recording, characterized in that the evaporated and withdrawn moisture by compression by means of a

Turbo compressor (3) is compressed to ambient pressure and at least a portion of the heated moisture to the

Outside wall of the recording is supplied, where the moisture condenses at least partially to heat them. 2. The method according to claim 1, characterized in that the interior (4) of the receptacle (1) to a pressure <0.5 bar, preferably in a range of 0.4 to 0,

2 bar is reduced and the heating of the interior or of the material to be dried by heating accordingly to a temperature of at least 40 °, preferably 50 to 65 ° C, in particular about 60 ° C.

3. The method according to any one of claims 1 or 2 for

Operating a tumble dryer with a drying room and / or a drum (1) and a heater, wherein the water vapor from the room interior or the

Drum interior (4) removed and an outside area (A) is fed, which is located outside the drum interior (4), wherein the pressure in the space inside or in

Drum interior (4) by evacuating and thus the Removal of the water vapor is reduced, characterized in that at least over a part of the duration of removal of the steam, the temperature in the interior or in the drum interior (4) is maintained at a temperature which is at least nearly so high that the moisture from the laundry evaporates.

4. The method according to any one of claims 1 to 3, characterized in that the compression by means of a

Radial turbocompressor is performed, for example, 2 or 3 stages executed, with or without shields.

5. The method according to any one of claims 1 to 4, characterized in that the compression by means of a

multi-stage radial turbo compressor takes place, which

is carried out at least two stages and wherein one or more radiators are provided between the individual compressor stages.

6. Tumble dryer at least characterized by:

a drying room, an evacuable drum (1) and / or a laundry room,

a heating device (10) for heating the drum or the laundry (11) arranged therein,

a turbo compressor (3), to evacuate the

Interior (4) of the drying space of the chamber and / or the drum (1) and removing the moisture from the

Drum, as well

a return (9) of the withdrawn moisture to the outer wall of the laundry chamber, the drying room or the drum (1).

7. Dryer according to claim 6, characterized in that the turbo compressor is a multi-stage radial turbo compressor is at least two stages, with one or more coolers between the individual

Compressor stages.

8. Dryer according to one of claims 6 or 7, characterized in that the drive motor of the

Turbo compressor is arranged high pressure side,

equipped with a permanent magnet rotor which is typically fluid-supported, wherein the fluid

For example, it can be water.

9. Dryer according to claim 8, characterized in that in the fluid storage a free-floating sleeve is mounted to reduce the shear forces in the camp.

10. Dryer according to one of claims 8 or 9, characterized in that the motor has an electrical power of typically 500 watts to 1 kilowatt at speeds of 300,000 to 700,000 revolutions / minute, preferably about 550,000 revolutions / minute Minute.

11. Dryer according to one of claims 6 to 10, characterized in that the return (9) opens into the intermediate space and that further a receptacle (5) is provided for condensed moisture from the

Gap.

12. Dryer according to one of claims 6 to 11, characterized in that an evacuable drying space is provided with a rotatable laundry drum disposed therein.

13. Dryer according to one of claims 6 to 12, characterized in that the evacuable drum (1) is a cylindrical drum with concave ends or side walls.

14. Dryer according to one of claims 6 to 13, characterized in that in one of the concave

Terminals an opening is provided which by means of a largely transparent material, such as

For example, a window made of quartz glass is covered, and that for the heating of the goods to be dried

additional heating device is provided, such as

For example, a halogen lamp, which is arranged in the region of the opening or the quartz glass window.