Clothes dryer e.g. tumble dryer has process air circuit that is arranged with additional heat exchanger for removing heat from process air circuit, and discharge of process air heat to ambient air

Area of the invention the invention concerns a laundry dryer with heat pump and auxiliary heat exchanger.

Background a laundry dryer with heat pump usually possesses a turning drum for the admission of the laundry which can be dried. The drum is arranged in a processing air cycle. In the processing air cycle warmed up processing air is led by the drum, then air is cooled down to the dehydration, heated again and led back into the drum. Further a heat pump cycle is intended, in which a medium is led by a condenser, a throttle organ (expansion valve), an evaporator and a compressor back to the condenser. With the evaporator the processing air is cooled, in order to withdraw their water, and with that condenser is then again warmed up it.

In CH 699,018 a laundry dryer is described, in whose processing air cycle an auxiliary heat exchanger is arranged, in order to withdraw from the system warmth. The drum possesses a horizontal axis of rotation, and the processing air intersperses the drum from the rear forward. With the auxiliary heat exchanger it concerns an air-to-air heat exchanger, which is out-arranged to exhaust processing air warmth to the ambient air.

Representation of the invention it places itself the task to develop a laundry dryer further of the kind described above in such a way that the drying time can be reduced.

This task is solved from the laundry dryer in accordance with requirement 1. An additional heating system accordingly is arranged is in the processing air cycle additionally to the condenser, with which the processing air can be warmed up. With such an additional heating system the equipment can be heated faster at the beginning of the process, and/or at least one part of the process can be accomplished at higher temperature.

The processing air cycle is out-arranged favourably to lead the processing air from the front to the back by the auxiliary heat exchanger. This permits it to lead the processing air withdrawing at the front from the drum directly and on short way to the entrance of the auxiliary heat exchanger.

In order to be able the auxiliary heat exchanger would drive off, must the warmth of the additional heating system be relatively large. Therefore the question arises, how the auxiliary heat exchanger in the equipment is to be accommodated.

In a preferential execution the auxiliary heat exchanger is arranged underneath the drum.

In another favourable execution the auxiliary heat exchanger is arranged above the drum.

In a further execution the auxiliary heat exchanger is attached at the back of the equipment.

Short description of the designs further arrangements, advantages and applications of the invention, and in particular different, particularly space saving possibilities for the arrangement of the components of the equipment, result from the dependent requirements and from the following description on the basis the figures. Show:

Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig.

Fig. 6 Fig. 7 a block diagram of the most important components of the laundry dryer, a first arrangement of the components in the laundry dryer, a second arrangement of the components in the laundry dryer, a third arrangement of the components in the laundry dryer, a fourth arrangement of the components in the laundry dryer, a fifth arrangement of the components in the laundry dryer and a sixth arrangement of the components in the laundry dryer.

Ways to the execution of the invention definitions:

The designations “back” and “front” are defined by the direction of the river of the processing air in the drum. In particular the processing air goes through the drum achsial (i.e. parallel to the horizontal axis of rotation) from their back to their front, i.e. the air inlet effected primarily from the back ago and the air outlet takes place primarily against the front of the drum.

Designations of the kind “up”, “below”, “over”, “under” refer to the intended assembly orientation of the equipment. If it is said that a construction unit A “below” (and/or “up” a construction unit B is arranged, then is to be understood by the fact that at least one part of the construction unit A is vertically underneath (and/or up) the construction unit B.

Basic structure:

The laundry dryer after Fig. 1 possesses a drum 1 for the admission of the laundry which can be dried. A processing air cycle is intended (which in Fig. 1 with pulled through lines is represented), in which processing air warmed up by the drum 1 is led, then cooled down and afterwards again heated and back into the drum 1 led.

In the processing air cycle, in particular between the blower 10 and the drum 1, an electrical additional heating system 9 is intended, which it permits to supply to the processing air aimed warmth e.g. when starting of the equipment, or it can are used, in order to generally raise the temperature level in the processing air cycle. The blower serves the processing air for the Umpumpen.

Further a heat pump cycle is intended (whereby the path of the medium in Fig, promoted by the heat pump cycle. 1 with scored lines is represented). The medium is promoted by a compressor 2 to a condenser 3, then by means of a throttle organ 5, e.g. to form capillaries or an expansion valve, to an evaporator 6 and then again back to the compressor 2. the evaporator 6 serves for it, the processing air to cool down and their water in this way to withdraw, while the condenser serves 3 to warm up the processing air again so that it can take up new water.

As from Fig. 1 further evidently, is intended in the processing air cycle an auxiliary heat exchanger 4. How/as entrance mentioned, he serves to withdraw from the processing air cycle warmth. In particular is it the amount of heat of the additional heating system 9 and the energy dissipation of the heat pump would drive off. Preferably it is arranged between the drum 1 and the evaporator 6, since it can withdraw also water at the same time there from air.

The auxiliary heat exchanger 4 is an air-to-air heat exchanger, which is flowed through on the one hand by the processing air and on the other hand by ambient air, whereby the processing air and the ambient air are preferably locally separate and cannot not mix itself. It is intended a far blower 7, with to cool which the ambient air is led by the auxiliary heat exchanger 4, in order these.

By the auxiliary heat exchanger 4 the processing air cycle withdrawed the thermal output over the number of revolutions of the blower 7 one specifies. This number of revolutions is determined dependent on a control 8 of the equipment, on at least a temperature in the heat pump cycle and/or processing air cycle. For this a temperature sensor 11 is arranged in the heat pump cycle. The control is out-arranged to steer the number of revolutions of the blower 7 dependent on the signal of the temperature sensor 11 e.g. as the blower 7 with larger achievement is operated, if the temperature rises. For example the blower can be switched on only then if the temperature exceeds a given threshold value. Preferably however the number of revolutions of the blower 7 by the control 8 is increased at increasing temperature continuously or at least in several steps.

The temperature-dependent control of the blower 7 makes it possible to supply e.g. when starting the laundry dryer the processing air cycle very fast energy so that the process temperature is rapidly reached, according to which however in normal operation overheating the heat pump cycle is prevented.

Preferably the temperature of the medium running in the heat pump cycle is determined, where this temperature corresponds approximately to the condensation temperature of the medium. This is input between condenser 3 and throttle organ 5 the case, or at the output the condenser 3 or the throttle organ arrangement of the components:

In the following some favourable arrangements of the components are shown in the equipment on the basis of different remark taping.

A first arrangement is in Fig. 2 represented. The approximately quaderförmige housing 14 of the equipment, which possesses a front 15, a back 16, perpendicularly to it standing vertical sides 17, a top side 18 and a ground 19, is evident. In the housing 14 the drum 1 with their horizontal axis of rotation 20 is arranged. The axis of rotation 20 stands perpendicularly to Vorderund back 15 and/or 16.

In the execution after Fig. 2 is arranged the components of the heat pump, and in particular the evaporator 6 and the condenser 3 as well as the compressor 2 underneath the drum 1 in the equipment base. Also the auxiliary heat exchanger 4 is underneath the drum 1 in the equipment base. The arrangement of these heavy components underneath the drum 1 leads to stable conditions of the equipment.

In the represented execution the auxiliary heat exchanger 4 underneath the evaporator 6 and the condenser 3. in this position is well accessible it a cleaning.

At the back 16 of the equipment are the blower 10 and the additional heating system 9 and it are intended a climb duct 21, in which the processing air is led by the blower 10 and the additional heating system 9 to the back of the drum 1.

As suggested with the arrows, the processing air flows through the drum 1 of the back 16 to the front and runs thereby approximately parallel to the axis of rotation 20. With equipment with Fronttüre air steps into a channel into the Türe (not shown), and then the front along downward to the auxiliary heat exchanger 4 is then led. Then the processing air is led toward of the front 15 to the back 16 by the auxiliary heat exchanger 4.

From there the processing air is then led into a channel 22 again against the front 15 to the evaporator 6.

Now the processing air of the front goes through 15 to the back 16 first the evaporator 6 and then the condenser 3, from where it arrives again at the blower 10 at the back 16.

Like far by an arrow 24 in Fig. 2 suggested, the ambient air of the blower 7 becomes (in Fig. 2 not represented) horizontal and transverse to the direction of flow of the processing air by the auxiliary heat exchanger 4 promoted, i.e.

the ambient air is led of a a side the 17 on the other hand.

Fig. a second possible arrangement, which itself of that one in accordance with Fig, shows 3. by the fact 2 differentiated between that the evaporator 6 and the condenser 3 now more deeply than the auxiliary heat exchanger 4 are arranged. The auxiliary heat exchanger 4 is underneath the drum 1, between the drum 1 and the evaporator 6 and the condenser 3.

Since the auxiliary heat exchanger is relatively warm 4, the arrangement has in accordance with Fig. 3 opposite that one of Fig. 2 the advantage that the warmth ascending from the auxiliary heat exchanger 4 does not impair the function of the evaporator 6.

In the execution after Fig. the processing air enters, leaves 3 again from the front the auxiliary heat exchanger 4 this to the back, by the channel 22 to the front of the evaporator is led and goes through on their way to the blower 10 before still the condenser 3.

A further arrangement, with which the auxiliary heat exchanger 4 is underneath the drum 1, is in Fig. 4 represented. In this execution the auxiliary heat exchanger 4 horizontal arranged beside the evaporator 6 is and the condenser 3. As in the remarks after Fig. 2 and 3 the processing air at the front 15 of the equipment is led downward here to the auxiliary heat exchanger. It goes through the auxiliary heat exchanger 4 toward of the front 15 to the back 16 and again in the channel 22 back to the front and to the evaporator 6 is then led.

The arrangement of the auxiliary heat exchanger 4 horizontal beside evaporators 6 and condenser 3 results in again a good thermal uncoupling, as from condenser 3 and auxiliary heat exchanger 4 ascending warm air does not impair the cooling within the range of the evaporator 6. The auxiliary heat exchanger can lie both on the left of and right from evaporator and condenser.

In the execution after Fig. the auxiliary heat diver 4 is arranged 5 above the drum 1 in the range of the top side 18 of the equipment. This arrangement makes it possible to arrange the drum 1 more deeply which e.g. during the arrangement of the equipment in a tower over a washing machine of advantage is.

The processing air of the drum 1 is led the front along 15 upward, enters from the front the auxiliary heat exchanger 4 and goes through this toward the back 16. Then the processing air steps 26 at the back 16 of the equipment into a first channel, into which it by the auxiliary heat exchanger 4 one leads downward. The first channel 26 can be arranged within the equipment (i.e. before the rear wall) or outside of the equipment (i.e. behind the rear wall), like this in Fig. 5 by means of a broken variant 26 " one suggests. The first channel 26 changes underneath the drum 1 into a second channel 27, in which the processing air is led to the front 15 of the equipment and to the entrance of the evaporator 6.

In the execution after Fig. the auxiliary heat exchanger 4 is arranged 6 above the drum 1, the way of the processing air is however somewhat shorter likewise than during the execution after Fig.

The processing air from the drum 1 is led first upward and then in a first air duct 28 against the back and into the auxiliary heat exchanger 4. It goes through the auxiliary heat exchanger 4 against the front 15 and enters then a second air duct 29, which is arranged at the front 15 of the laundry dryer. In the second air duct 29 the processing air is led downward by the auxiliary heat exchanger 4 around evaporators 6.

The first Luftkana128 runs in the cavity between the drum 1 and an upper edge of the laundry dryer.

In the execution after Fig. the auxiliary heat exchanger 4 arranged 7 at the back 16 of the laundry dryer is.

From the front of the drum 1 withdrawing processing air by a first channel 30, which in the cavity between the drum 1 and an upper edge of the laundry dryer runs, against the back into the upper end of the auxiliary heat exchanger 4 one introduces. Then air is led from above approximately down by the auxiliary heat exchanger 4 and enters then a second channel 31, by which it at the front 15 the equipment arrives and enters after it the evaporator 6.

In summary a laundry dryer is described thus among other things, which possesses a drum 1 with horizontal axis of rotation as well as a heat pump with an evaporator 6 and a condenser 4. The processing air steps against the front 1 of the equipment from the drum 1 from (with front battery chargers usually in one by the -10re running channel) and after is e.g. down led, in order to then enter the auxiliary heat exchanger 4. With the auxiliary heat exchanger 4 it concerns an air-to-air heat exchanger, in which the processing air is cooled down. The processing air withdraws to the rear from the auxiliary heat exchanger 4 and to the front of the equipment and to the evaporator 6 is then led there. Afterwards air arrives by the condenser 3, a blower 10 and an additional heating system 9 again back at the drum 1. the auxiliary heat exchanger 4 underneath the drum 1 is favourably arranged. The descriptive arrangement variants are characterised by very compact structure.

While in the available registration preferred remarks of the invention are descriptive, it is to be pointed out clearly that the invention is limited to these not and can in also different way within the range of the following requirements be implemented.