EP2004900B1 - Method and drier for drying pieces of wool - Google Patents

Abstract

In a first phase of heating and stationary drying to reach a moisture of 20%, movement lasts up to 5 s. The resting interval is 1 - 20 minutes. A second, crease-removal phase follows, in which movement lasts from 10 s to 6 minutes and the resting interval is 5 s - 2 m. In the heating and stationary drying phase, movement lasts for 0.1 to 0.6 s or 0.15 to 0.25 s. During the second, crease-removal phase, movement lasts for 20 s - 4 minutes. The drum (3) rotary speed is kept below that causing the woolens to rest against it. Its direction of rotation varies. Heating phase and stationary drying phase last until the wool moisture reaches 10%-20%. During crease removal, the ratio between intervals of movement and rest is 15 - 20. In the corresponding dryer, a controller (11) interrupts drum rotation and sensors (9, 10) determine the moisture. An independent claim IS INCLUDED FOR the corresponding dryer.

Description

The invention relates to a method for drying wool pieces in a dryer, which is equipped with a drum which is rotatably mounted in both directions, in which alternate at least one period of motion and at least one standstill period of the drum, and a dryer for performing this method.

Wool pieces, these are textiles made of wool fabrics, are characterized by the fact that they must be treated gently during a drying process, otherwise there is a risk of their damage by matting, shrinking or forming nubs. It is known that wool pieces in a conventional dryer can not be dried, as this usually leads to an unduly high shrinkage of the wool. A continuous movement of the drum is performed because the cost of the drum, the process air blower and the condensation dryer and the cooling air blower are driven by a single motor. For drying woolen pieces, on the one hand, as little mechanical energy as possible should be supplied to the woolen pieces, but on the other hand, all sides of the woolen pieces should be turned toward the warm airflow by sufficient movement to achieve an acceptable drying time.

Finally, it is known that when moisture in a wool piece decreases during drying, wrinkles are fixed by the hot process air when the wool piece rests during drying. To reduce wrinkling and wrinkling, a wool piece must be moved strongly during drying, so that wrinkles and wrinkles can be eliminated by the onset of laundry.

There are thus opposite requirements when drying woolen pieces, since the smallest possible movement of the wool pieces should take place in order to limit shrinkage and entanglement, but on the other hand a As much movement of the wool pieces should take place in order to prevent the formation of wrinkles and wrinkles.

In the DE 19 24 961 A a method for drying sensitive types of fabric in a tumble dryer with a rotatably mounted drum and means for flowing through the drum with heated air is described, in which the drum is rotated so fast during the majority of the drying process that the laundry items due to the centrifugal forces acting on lie against the drum without being further moved. In the method, it is advantageous to divide the drying process into periods of provision of the laundry items and periods of tumbling of the laundry items. The temporal portion of the periods of concern in the total dry season is significantly greater than the temporal portion of the periods of clutter. From the DE 22 33 698 A A similar process is apparent, this process also including washing and spinning the laundry then to be dried.

In the DE 101 62 923 A If a drying process gem. In the preamble of claim 1 and a drying device for drying textiles described in which textiles are dried with a reduced moisture content at a reduced temperature of the dry air and / or a reduced intensity of movement of the textiles.

From the WO 2005/064071 A2 go out a method and an apparatus for drying laundry, with a crease-resistant phase is provided following a drying program in which the dried laundry is temporarily moved and temporarily not moved. This is to fix the wrinkles in the laundry by regular loosening to be avoided.

It is therefore an object of the invention to provide a method and a dryer for drying wool pieces, in which there is no or negligible felting or shrinkage of the wool pieces and the creasing is minimized.

1. (a) in einer Aufheizphase und einer stationären Trocknungsphase bis zu einer Feuchte der Wollestücke von maximal 20 % die Dauer der Bewegungsperiode bis zu 5 Sekunden beträgt und die Dauer der Stillstandsperiode zwischen 1 und 20 Minuten beträgt, und
2. (b) in einer anschließenden Entknitterphase die Dauer der Bewegungsperiode zwischen 10 Sekunden und 6 Minuten beträgt und die Dauer der Stillstandsperiode zwischen 5 Sekunden und 2 Minuten beträgt.

Accordingly, the invention provides a method for drying wool pieces in a dryer with a rotatably mounted in both directions drum according to claim 1, wherein alternate at least one movement period and at least one standstill period, so that

1. (a) in a heating phase and a stationary drying phase up to a humidity of the wool pieces of a maximum of 20%, the duration of the movement period is up to 5 seconds and the duration of the stoppage period is between 1 and 20 minutes, and
2. (b) in a subsequent detack phase, the duration of the movement period is between 10 seconds and 6 minutes and the duration of the stoppage period is between 5 seconds and 2 minutes.

The invention also relates to a dryer for carrying out this method.

It is understood that a "dryer" is not only a device that is intended solely for drying laundry. Rather, a dryer is also a device to understand what textiles can both wash and dry. In such a device, the drying method according to the invention can advantageously be combined with a method specially adapted to wool pieces for washing laundry.

Preferred embodiments of the invention are also set forth in the subclaims.

According to the invention, a drying process is used for drying the wool pieces, in which exactly certain movement periods in which the drum rotates alternate with precisely determined periods of standstill, in which the drum stands still. In this case, in a heating phase and a stationary drying phase, the wool pieces are still relatively humid, only very short periods of movement, in which the wool pieces are only turned over and not intensively moved against each other. The corresponding standstill periods are on the other hand quite long, so that the drying of the wool pieces takes place predominantly in resting state. This avoids felting and shrinkage.

According to the invention, to prevent the crumpling of the items of laundry in a decalcifying phase, which occurs after a large degree of dehumidification of the wool pieces, another sequence of movement periods and periods of standstill takes place in the drying process. The movement periods compared to the stationary drying phase are significantly longer. With increasing drying of woolen pieces, the risk of entanglement decreases greatly; a stronger movement of the wool pieces in the smooth drum then avoids the formation of wrinkles.

In the heating phase and the stationary drying phase of the method according to the invention, the duration of the movement period is preferably between 0.1 and 0.6 seconds, particularly preferably between 0.15 and 0.25 seconds.

It is preferable that, in the decapitating phase, the duration of the period of motion is between 20 seconds and 5 minutes, more preferably between 30 seconds and 4 minutes. It is especially preferred if the duration of the movement period is between 2.5 and 3 minutes.

The laundry drum is generally operated at a rotational speed ("drum speed") between 45 and 60 revolutions per minute, preferably between 50 and 54 revolutions per minute, in each movement period.

Preferably, in each movement period, the drum speed is below the application speed, wherein the application speed is the drum speed, from which the wool pieces abut due to the centrifugal force on the inner wall of the drum.

Preferably, the direction of rotation of the drum may vary.

The heating phase and stationary drying phase are preferably carried out in the process according to the invention up to a moisture content of the wool pieces in the range between 10 and 20%.

In the decapping phase of the method according to the invention, the ratio between the duration of the movement period and the duration of the standstill period is preferably 15 to 20.

The inventive method can both during drying of wool pieces according to the circulating air principle, in which the dry air is guided in a closed circuit and heated before contact with the wool pieces and cooled after contact for condensation of moisture contained in the dry air, as well as applied to the exhaust air principle in which the dry air escapes from the dryer after contact with the wool pieces.

In the used wool pieces, the initial moisture is generally about 50 to 60%. In the heating phase, the temperature of the dryer is generally increased from room temperature to a maximum temperature which is then substantially maintained during the stationary drying phase.

The maximum temperature in the process can be varied within wide limits. In general, the maximum temperature is about 70 ° C for a condensation dryer. For a vented dryer, the maximum temperature is generally lower.

In the heating phase and the stationary drying phase of a method not according to the invention, the duration of the standstill period is in particular between 1 and 20 minutes, preferably between 3 and 15 minutes, and preferably until the moisture of the wool pieces has dropped to a value of 30%.

The heating of the dry air can be turned off or turned on during the standstill period. Preferably, the heating of the dry air is turned on.

In a preferred embodiment of a method not according to the invention, below a maximum humidity of 30% in the heating phase and the stationary drying phase, the duration of the standstill period is preferably between 1 and 10 minutes, more preferably between 2 and 8 minutes.

The total duration of the standstill periods in the process is generally greater than the total duration of the drum movement periods.

The method generally uses a device for determining the moisture content of the woolen pieces in the dryer.

The determination of the moisture of the wool pieces can be done in various ways. For example, as sensors, two electrodes may be introduced into the laundry drum so as to contact the wet wool pieces. An electrical voltage is then applied to the electrodes and the current intensity or the electrical conductance between the electrodes is measured. If the measured current intensity or the measured electrical conductance falls below a respective predetermined threshold, this can be concluded that the end of the heating phase and the stationary drying phase have been reached. In this case, the method according to the invention advantageously provides for a change to the decapping phase.

A method is provided in which a measurement of the moisture in the wool pieces to be dried is not provided and only a time-oriented control of the drying process is provided. Such a controller may be designed based on experience from a moisture-oriented drying process in a suitably equipped model dryer and / or a corresponding simulation.

In such a method, in particular the heating phase and the stationary drying phase are summarized and the drum is operated during the corresponding period as described above for the stationary drying phase.

Such a method preferably operates a de-crescent phase for the last 10 to 15 minutes of the total time scheduled for the method with the above-described motion and standstill rhythms.
The invention also relates to a dryer with a rotatably mounted around both directions drum for performing the method according to the invention. In a preferred embodiment, the dryer is equipped with sensors for the humidity, in particular with electrodes for determining electrical currents or the conductivity as a measure of this.

The dryer can be an exhaust air dryer or a condensation dryer, in particular also a dryer with a heat pump cycle.

The drying method and dryer of the present invention have numerous advantages. For example, the mutually exclusive requirement profiles for the prevention of felting and shrinking and the formation of wrinkles and wrinkles are optimally taken into account.

An embodiment of the invention will be described below with reference to the in FIG. 1 sketched example of a dryer explained.

FIG. 1 shows a vertically cut drum dryer.

The in FIG. 1 shown dryer 1 has a rotatable about a horizontal axis drum 3, are mounted within which driver 4 for moving laundry during a drum rotation. A heater 12, a capacitor 13 as well a fan 14 are provided to produce an air circuit closed by an air duct 2 through the drum 3 therethrough. In this case, heated air from the heater 12 is passed from behind through its perforated bottom into the drum 3, where it comes into contact with the laundry to be dried and flows through the filling opening of the drum 3 to a lint filter 6 within a door closing the filling opening 5. Subsequently the air flow in the door 5 is deflected downwards and directed from the air duct 2 to the condenser 13. There, as a result of cooling, the moisture absorbed by the air from the wool pieces (not shown) located in the drum 3 condenses and is removed. After the condenser 13, air from the blower 14 is again directed to the heater 12. The drum 3 is mounted on the rear floor by means of a pivot bearing, not shown, and front by means of a bearing plate 7, the drum 3 rests with a brim on a sliding strip 8 on the bearing plate 7 and is held at the front end.

The control device 11 controls the execution of the drying process, in particular the interruption of the rotation of the drum 3. The control device 11 is equipped in a preferred embodiment such that a measurement of the moisture content of the wool pieces can be performed and taken into account in the drying process. For this purpose, electrodes 9 and 10 are mounted in the lower region of the drum 3, to which the control device 11 applies an electrical voltage, in order then to measure the intensity of an electric current flowing between the electrodes 9 and 10 or of the electrical conductance between these electrodes for the humidity of the wool pieces in the drum 3 to determine.

Claims (10)

1. Method of drying woollen articles in a dryer (1) with a drum (3) mounted to be rotatable in two directions, in which at least one movement period and at least one standstill period of the drum (3) alternate, characterised in that

   (a) in a heating-up phase and a stationary drying phase up to a moisture content of the woollen articles of at most 20% the duration of the movement period is up to 5 seconds and the duration of the standstill period is between 1 and 20 minutes and

   (b) in a subsequent crease-removal phase the duration of the movement period is between 10 seconds and 6 minutes and the duration of the standstill period is between 5 seconds and 2 minutes.
2. Method according to claim 1, characterised in that in the heating-up phase and the stationary drying phase the duration of the movement period is between 0.1 and 0.6 seconds.
3. Method according to claim 2, characterised in that in the heating-up phase and in the stationary drying phase the duration of the movement period is between 0.15 and 0.25 seconds.
4. Method according to any one of claims 1 to 3, characterised in that in the crease removal phase the duration of the movement period is between 20 seconds and 4 minutes.
5. Method according to any one of claims 1 to 4, characterised in that the drum (3) is rotated at a rotational speed below a laying-on rotational speed, wherein the laying-on rotational speed is the drum rotational speed from which the woollen particles bear against the inner wall of the drum due to centrifugal force.
6. Method according to any one of claims 1 to 5, characterised in that the rotational speed of the drum (3) varies.
7. Method according to any one of claims 1 to 6, characterised in that the heating-up phase and the stationary heating phase are performed up to a moisture content of the woollen articles in the region between 10 and 20%.
8. Method according to any one of claims 1 to 7, characterised in that in the crease removal phase a ratio between the duration of the movement period and the duration of the standstill period lies in the range of 15 to 20.
9. Dryer (1) with a drum (3) which is mounted to be rotationable in two directions, for performance of the method according to any one of claims 1 to 8, characterised in that the dryer (1) is equipped with a control (11) for interruption of the rotation of the drum (3).
10. Dryer (1) according to claim 9, characterised in that it is equipped with sensors (9, 10) for determination of the moisture content.

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