EP2238287B1 - Exhaust air dryer having fan - Google Patents

Description

The invention relates to an exhaust air dryer with an interior bounding housing, wherein disposed in the interior of a drying chamber for objects to be dried, a supply air duct between a first Zulufteingang and the drying chamber for supply air, a heater for heating the supply air in the supply air duct, a fan, with which the heated supply air can be guided through the drying chamber, and an exhaust air duct between the drying chamber and an exhaust air outlet on the housing for exhaust air. Such an exhaust air dryer respectively emerges from the documents DE 30 00 865 A1 EP 12 70 793 A and EP 1 813 712 A1 ,

In general, a tumble dryer is designed and operated as an exhaust or condensation dryer. An exhaust air dryer generates warm process air, which is blown to absorb moisture through the laundry to be dried and then discharged from the tumble dryer. In any case, when the exhaust air dryer is installed within a building, a corresponding exhaust hose must be used for discharging, through which the process air laden with moisture is led out of the building - be it directly or through a permanently installed exhaust air duct. A condensation dryer whose operation is based on the condensation of moisture evaporated by means of warm process air from the laundry requires no exhaust hose and allows energy recovery from the heated process air, for example by using a heat pump.

On the other hand, in an exhaust air dryer, the air laden with moisture after passage through a laundry drum is generally discharged from the dryer, and heat recovery does not take place. However, out of the DE 30 00 865 A1 In this case, ambient air (of, for example, 20 ° C. and 60% relative humidity, so-called supply air) flows along heat exchanger surfaces of an air-to-air heat exchanger, where it is cooled by the warm process air coming from the drying chamber, which is also the cooling air Heat exchanger flows through, heated. Depending on the cooling capacity or the Heat exchange creates condensate which is collected or pumped away in a container (condensate tray).

In this known dryer, a fan for conveying the process air (supply air and exhaust air) is used. In addition, known dryers generally have only one motor, which drives both the rotary drying chamber (washing drum) and the fan.

Finally, devices in dryers are known which are intended to influence the guidance of the process air. In the DE 43 06 217 B4 a program-controlled tumble dryer is described, in which the process air is guided by means of a blower in a closed process air duct, in which particularly arranged closure devices are located. Depending on the operating state (heating phase, laundry drying phase, reaching the maximum permissible temperature), the closure devices are actuated suitably.

In a vented dryer, it is often desirable to be able to use the longest possible exhaust duct or the longest possible exhaust hose to have more flexibility with regard to the installation of the dryer, in which the exhaust air is not discharged into the interior of a room.

An object of the present invention is therefore to provide an exhaust air dryer with high energy efficiency, which can be operated with only one motor. Preferably, this dryer should allow to use a longer exhaust duct and exploit the waste heat generated in the dryer.

The solution to this problem is achieved by this invention by a vented dryer with the features of the independent claim.

Preferred embodiments of the exhaust air dryer according to the invention are listed in corresponding dependent claims.

The invention thus relates to an exhaust air dryer with a housing bounding a housing, wherein are arranged in the interior of a Drying chamber for objects to be dried, a Zuluftkanal between a first Zulufteingang and the drying chamber for supply air, a heater for heating the supply air in the supply air duct, a fan, with which the heated supply air can be guided through the drying chamber, and an exhaust duct between the drying chamber and a Exhaust air outlet on the housing for exhaust air, wherein the fan is a double-flow fan with a first flood and a second flood, wherein the first flood in the exhaust duct and the second flood is arranged in the supply air duct.

Here, the two floods are sealed against each other, so separated from each other in terms of flow.

According to the invention, air from the interior of the exhaust air dryer, which is heated by waste heat of various components of the exhaust air dryer, made available for the drying process in the exhaust air dryer. In this way, a loss of usable heat from the exhaust air dryer can be avoided and thus the effectiveness of the drying process can be increased. In a preferred embodiment of the invention, the drying chamber is rotatable, in particular carried out according to conventional practice for tumble dryer as a drum, and drivable by a motor, wherein the first air inlet inlet for sucking in air from an environment of the engine is arranged. Thus, a thermally loaded component of the exhaust air dryer, here the engine, cooling provided by the first air inlet is placed so that when sucking air into the first air inlet an air flow is formed, which flows past the loaded component and excess heat, the was taken from such air, dissipates the charged component.

Further preferred is an embodiment of the exhaust air dryer according to the invention, in which the motor is arranged both for driving the drying chamber and for driving the fan. Thus, the use of a single motor for driving the drying chamber and blower is still possible. In addition, the engine waste heat is used and thus not only achieved energy savings, but also a protection of the engine. Due to the active cooling of the motor this can be made smaller in terms of laminated core and winding. It is possible to use a relatively short, inexpensive shaft journal on one side of a motor for driving the fan.

In all embodiments, it is advantageous that the design of the interior and of the air paths in the region of the engine and / or optionally of another component enables effective removal of the waste heat from the engine or from the other component.

The flow rate of the two floods in the twin-flow fan of the exhaust air dryer according to the invention can vary within wide ranges. Preferably, the first flood and the second flood each have a flow rate of 50 m ³ / h to 500 m ³ / h.

The heating in the supply air duct for heating the supply air (process air) may preferably be an electric heating (electrical resistance heating) or a gas heating. Since, as the degree of drying of the objects to be dried in the exhaust air dryer decreases, the energy required for drying decreases, the heating is appropriately regulated, that is to say in accordance with the invention. As the degree of drying progresses, its heat output is reduced.

In the exhaust air dryer according to the invention, it is preferred that a heat exchanger is provided, in which a heat exchange between the supply air duct and the exhaust duct can take place. Here, the warm air from the drying chamber is used for heating the process air. In this case, a heat exchange between the first and / or the second sub-channel and the exhaust air channel can preferably take place in the heat exchanger.

When using a heat exchanger to cross the supply air duct and the warm air from the drying chamber having exhaust duct or the heat source of the heat pump in general.

A particularly preferred embodiment of the exhaust air dryer according to the invention is characterized in that in the supply air duct, a flow controller, in particular a controllable flap or a controllable valve, is arranged. Such a flow regulator in the exhaust air dryer according to the invention can be designed differently, as long as it can regulate a control of the flow of process air. Preferably, the flow regulator is a flap or a valve.

This flow regulator can regulate the air passage in various ways. The type of control can depend on the arrangement and structure of the flow controller. Thus, the flow regulator can regulate only one air passage through the supply air duct, in particular so far that the contribution of the second flood of the blower to the delivery capacity is canceled. This can, if appropriate, in conjunction with a corresponding control of the heater, in particular the temperature level of the heated supply air influenced and in particular a faster heating of the objects to be dried in the drying chamber can be achieved. Alternatively or in addition thereto, the flow regulator can simultaneously release a second supply air inlet and thus in particular offer an increased range of control. The flexible utilization of the waste heat of a present in the exhaust air dryer engine or another component via a controllable by means of the flow control supply air from the interior allows a process air flow is increased by the exhaust air dryer until it reaches a predetermined temperature. The invention enables a cost-effective control of the process air flow through the exhaust air dryer.

The exhaust air dryer according to the invention of any design has the advantage of being very energy efficient and also to allow faster drying of laundry items. The latter applies because the invention allows an increase of the air flow through the exhaust air dryer. The increase of the air flow in turn allows an increase in the heating power to be applied, thus further accelerating the drying process is possible. In addition, it is well possible to take additional measures for at least partial recovery of the heat energy spent in the drying process. In particular, the use of a cross-flow heat exchanger for a further increase in energy efficiency is possible.

• Figur 1 eine Skizze einer Ausführungsform eines Ablufttrockners;
• Figur 2 eine Skizze einer anderen Ausführungsform eines Ablufttrockners;
• Figur 3 ein Ausführungsbeispiel für ein zweiflutiges Gebläse;
• Figur 4 eine Schrägansicht, und
• Figur 5 eine Seitenansicht einer weiteren Ausführungsform eines Ablufttrockners.

Embodiments of the invention will become apparent with reference to the figures of the drawing from the following description. Show it:

• FIG. 1 a sketch of an embodiment of a vented dryer;
• FIG. 2 a sketch of another embodiment of a vented dryer;
• FIG. 3 an embodiment of a double-flow fan;
• FIG. 4 a perspective view, and
• FIG. 5 a side view of another embodiment of a vented dryer.

FIG. 1 shows a vertical section through a vented dryer 1 as a sketch. A housing 2 circumscribes an interior 3 of the exhaust air dryer 1, in which interior 3 a control device 4 is arranged, which serves both to receive control commands from a user and to operate and control the functional components of the exhaust air dryer 1, in particular those components, which are mentioned below. Means by which the user receives information from the control device 4 and gives the control device 4 corresponding control commands are not shown for the sake of clarity. Next arranged in the housing 2 is a rotatable about an axis 5 drying chamber or drum 6, in which the wet objects to be dried must be introduced. A supply air duct 7 is provided in which air is sucked in through a first supply air inlet 8 and supplied to the drum 6 for drying the moist objects. The first Zulufteingang opens in the interior 3, so that it can be sucked through him, which was preheated by the release of heat from the functional components of the exhaust dryer 1, air. A housing 2 as shown here is usually not carried out sealingly against the environment of the exhaust dryer 1; such would not be necessary or useful for the function of the exhaust air dryer 1 in any way. Rather, there are in the housing a plurality of columns or slots 9, which are symbolically represented here by arrows 9 and through which air from the environment of the exhaust air dryer 1 can get into it without significant hindrance. A heater 10, executable known as electric heater 10 or gas heater 10 is disposed in the supply air duct 7, as well as a blower 11 to promote the supply air.

Behind the drying chamber 6, the now laden with moisture air, which is now called "exhaust" passes through an exhaust duct 12 and a lint filter 13 for catching entrained lint (which are to be understood small fiber particles, which separates the air flow from the objects to be dried) to an exhaust air outlet 14 on the housing 2. According to common practice and regulation, the exhaust air outlet 14 can not be easily left open when the exhaust air dryer 1 is placed inside a building; rather, a hose or the like must be connected, with which the exhaust air laden with the moisture can be led out directly from the building.

In the exhaust air dryer 1 described here, the blower 11 is designed as a double-flow blower 11, which means that it combines two independent partial blower or floods 15 and 16 in itself. Of these two floods 15 and 16, a first flood 15 is disposed in the exhaust duct 12, a second flood 16, however, in the supply air duct 6. In this way, the two floods 15 and 16 work in series and jointly promote the air flow of supply air or exhaust air through the Exhaust air dryer 1. This exhaust air dryer 1 therefore has the advantage of being very energy efficient and also allowing faster drying of laundry items. The latter applies because the twin-flow fan 11 allows an increase of the air flow through the exhaust air dryer 1. The increase of the air flow in turn allows an increase of the heating power to be applied by the heater 8, whereby a further acceleration of the drying process is possible. In addition, it is quite possible to take additional measures for at least partial recovery of the heat energy spent in the drying process, which will be discussed in detail below.

The two floods 15 and 16 of the blower 11 are driven by a motor 17, which also rotates the drum 6. This rotation is done via a connected to the motor 17 pulley 18 and here indicated by a dashed arrow, around the drum 6 and the pulley 18 looped endless belt 19th

The heat exchanger 20 is part of both the supply air duct 7 and the exhaust duct 12; it allows a transfer of heat from the exhaust air to the supply air, according to a recovery of heat energy that would otherwise be dissipated with the exhaust air from the exhaust air dryer 1. It should be noted that the thus caused cooling of the exhaust air can lead to condensed out of this moisture. If necessary, take precautions to collect and dispose of this condensed moisture; to appropriate measures in a condensation dryer of known design, which are readily transferable to the exhaust dryer 1 shown here, it should be noted.

FIG. 2 shows parts of a comparison with the execution according to FIG. 1 modified embodiment of a vented dryer 1. the change is that the supply air duct 7 is supplemented between the second flood 16 and the heat exchanger 20 to a flow controller 21 in the form of a movable flap 21. By this flap 21, the influence of the second flood 16 on the incoming air flowing in the supply air 7 can be completely or partially canceled. This allows regulation of the air flow. In particular, by reducing the air flow, an increased temperature in the air flow after passing through the heater 8 can be effected, which may be of importance for the purpose of accelerated heating or even drying of the moist objects in the drying chamber 6.

In the present case, the flow regulator 21 is designed such that it releases a second inlet inlet 22 as it closes off the part of the supply air duct 7 with the second flood 16. This ensures that, regardless of the position of the flow controller 21 always a certain flow of supply air possible and overheating of the heater 8 is excluded.

In the FIG. 3 is a double-flow fan 11, designed as a radial fan 11 and driven by the motor 17, shown. The floods 15 and 16 are sealed against each other. A single impeller 23 is present, each flood 15 or 16 is one half of this impeller 23.

The FIGS. 4 and 5 show an oblique view and a side view of a vented dryer 1 to illustrate the geometric relationships in which 11 advantages are achieved by the application of a double-flow blower. The interior 3 in the housing 2 most consuming component of the exhaust dryer 2 is the drum 6, which can not be reduced in terms of development of space for other components. If a better blower effect is desired, then the installation space for an enlargement of the blower 11, which according to conventional practice is located obliquely below the drum 6, is also limited. With the introduction of the double-flow blower 11, this problem is solved advantageous, and created a vented dryer 1 with improved throughput of supply air and exhaust air.

LIST OF REFERENCE NUMBERS

1

vented dryer

2

casing

3

inner space

4

control device

5

axis

6

drying chamber

7

supply air duct

8th

First air intake

9

Slot in the housing

10

heater

11

fan

12

exhaust duct

13

lint filter

14

exhaust air outlet

15

First tide

16

Second flood

17

engine

18

pulley

19

belt

20

heat exchangers

21

Flow regulator, flap

22

Second air intake

23

Wheel

Claims (10)

1. Exhaust air dryer (1) with a housing (2) bounding an interior space (3), wherein arranged in the interior space (3) are a drying chamber (6) for articles to be dried, a feed air channel (7), which is between a first feed air inlet (8) and the drying chamber (6), for feed air, a heater (10) for heating the feed air in the feed air channel (7), a fan (11) by which the heated feed air can be conducted through the drying chamber (6), and an exhaust air channel (12), which is between the drying chamber (6) and an exhaust air outlet (14) at the housing (2), for exhaust air, characterised in that the fan (11) is a double-flow fan (11) with a first flow (15) and a second flow (16), wherein the first flow (15) is arranged in the exhaust air channel (12) and the second flow (16) in the air feed channel (7).
2. Exhaust air dryer (1) according to claim 1, characterised in that the drying chamber (6) is rotatable by a motor (17) arranged in the housing (2) and that the first feed air inlet (8) is arranged for suction of air out of an environment of the motor (17).
3. Exhaust air dryer (1) according to claim 2, characterised in that the motor (17) is arranged not only for driving the drying chamber (6), but also for driving the fan (11).
4. Exhaust air dryer (1) according to any one of the preceding claims, characterised in that the first flow (15) and the second flow (16) each have a throughflow capacity of 50 m³/h to 500 m³/h.
5. Exhaust air dryer (1) according to any one of the preceding claims, characterised in that the heater (10) comprises a gas or electric heater (10).
6. Exhaust air dryer (1) according to any one of the preceding claims, characterised in that a heat exchanger (20) is present in which a heat exchange can take place between the feed air channel (7) and the exhaust air channel (12).
7. Exhaust air dryer (1) according to any one of the preceding claims, characterised in that a throughflow regulator (21) is associated with the feed air channel (7).
8. Exhaust air dryer (1) according to claim 7, characterised in that the throughflow regulator (21) is arranged between the second flow (16) and the heater (10).
9. Exhaust air dryer (1) according to one of claims 7 and 8, characterised in that the throughflow regulator (21) is a flap valve (21).
10. Exhaust air dryer (1) according to any one of claims 7 to 9, characterised in that a second feed air inlet (22), which can be selectably freed by the throughflow regulator (21), is associated with the throughflow regulator (21).

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