EP2103731A2 - Drying device with at least two drums - Google Patents

Abstract

The laundry drier has two or more rotating drums (21). These are mounted on a spider (13) which allows them to be moved between the drying zone (7) in the top section (3) of the machine and the loading (9) and unloading (11) sections at its base (5).

Description

In laundries and hotels naturally accumulate large quantities of washed laundry, which must be dried. In times of rising energy prices, the energy efficiency of this drying process is becoming increasingly important.

At the same time, space is a scarce commodity in commercial real estate, so that a drying device should also have the best possible use of space.

From the EP 0 395 685 B1 a drying device is known which operates in so-called batch mode. In order to minimize the energy requirement for drying, the drying gas is circulated in this device and the moisture contained in the drying gas after flowing through the laundry to be dried is removed by a condensate separator.

A disadvantage of this drying device is that for loading and unloading the drying device a large part of the same must be cooled and then reheated. In addition, no laundry can be dried during the loading and unloading. As a result, the energy efficiency and performance are not optimal.

From the DE 694 06 546 D2 There is known a drying apparatus which operates continuously. In this case, the drying material is fed to a drying zone via belt conveyors. In the drying zone, the drying material is transferred from the first belt conveyor to a second belt conveyor, which moves the material to be dried through the drying zone. Subsequently, the dried material to be dried is transferred to a third belt conveyor and led out of the drying zone. A disadvantage of this device are the great equipment and the large footprint.

From the DE 583 260 a drying device is known in which the material to be dried in different drums is successively passed through different drying zones. Each drying zone includes a separate housing, its own fan and its own heat exchanger. The complex construction results in high production costs and a large space requirement. In addition, energy efficient operation of the drying device is prevented or at least made more difficult.

The invention has for its object to provide a drying device, with respect to Energy efficiency and space requirements advantageously advances the state of the art and also offers many degrees of freedom in terms of process optimization.

This object is achieved according to the invention in a generic drying device with the features of Anpruchs 1.

In an advantageous embodiment of the invention, the means for conveying the item to be dried comprises at least two drums for receiving the item to be dried and a turnstile, wherein at the turnstile for each drum, a boom is present and wherein the drums are rotatably mounted on the arms.

The positioning of the drums in the room by a turnstile is characterized by a particularly simple and therefore also robust construction.

Alternatively, it is also possible to guide the drums with the aid of a tooth or wheel rim, a rail system, as well as toothed belts or chains through the drying room.

The drums of the invention serve as a transport container to transport the material to be dried from a loading station in the drying zone. In addition, the drums are used for transporting the material to be dried within the drying zone and for subsequently removing the dried material to be dried out of the drying zone and into an unloading station.

By using drums as a transport container, the loading and unloading of the drums can be decoupled from the actual drying process, so that a continuous drying of drying material and a constant temperature of the drying zone are possible. As a result, the efficiency of drying is significantly increased and it accounts for cooling and heating losses, as inevitably incurred in batch mode.

Due to the circular movement, on which the drums are conveyed from the loading station into the drying zone and into the unloading station with the aid of the turnstile claimed according to the invention or of the tooth or wheel rim, a very compact design of the drying device according to the invention is possible. Namely, the loading station and the unloading station can be arranged vertically below the drying zone, so that the drying device according to the invention requires only a small base area.

Although rails, chains or belt drives usually require a slightly higher design effort, but allow more degrees of freedom with respect to the tracks on which the drums can be moved through the dryer.

Characterized in that several drums are provided according to the invention, a drum located in the loading station can be loaded parallel to the drying and a drum located in the unloading station are cooled and discharged.

For example, since there may be two drums in the drying zone, while there is one drum in the loading station and one drum in the unloading station, the loading and unloading times may depend on the drying times be decoupled. In addition, it is possible to move the drums within the drying zone, so that after a first partial drying, the drum can be moved to another area of the drying zone. This is particularly advantageous if the drying is to take place in two phases. For example, this can be achieved by a countercurrent flow of superheated steam or a vapor-air mixture or it can supportive to a drying with superheated steam regionally microwave or other radiant heating can be provided.

If a turnstile is used to transport the drums, a rotation axis of the turnstile preferably extends substantially horizontally. This ensures that by rotating the turnstile the drums perform a movement in the direction of the vertical axis, so that the inventive arrangement of a drying zone above the loading station and the unloading station is particularly easy to implement.

The same applies if, as claimed in a further advantageous embodiment, the axes of rotation of the drums are substantially horizontal.

In order to simplify the loading and unloading of the drums, it is provided that the drums have a closable loading opening, in particular on its outer surface.

The housing accommodating the drying zone is advantageously thermally insulated to minimize the heat losses during the drying process. In addition, the housing is gas and gas at least in the drying zone steam-tight, so that the drying gas can not escape uncontrolled.

In a further advantageous embodiment of the invention, the housing in a lower half of a loading station and / or an unloading station, the drums can be transported by turning the turnstile or actuation of the alternative provided conveyors in the loading station and the unloading station.

Of course, it is also conceivable that a combined loading and unloading station is available. This is especially true when the number of drums is comparatively low and the time intervals between the actuations of the conveyor, such as the turnstile, and the drying time is comparatively long. Then namely, in a station and without the drum located in this station would have to be moved, the dried material to be dried contained in the drum and filled new moist drying material. This combined loading and unloading could, for example, in drying devices with a total of three drums, each offset by 120 ° to each other on the arms of the turnstile, be advantageous.

In order to dissipate the moisture removed from the drying material during operation, a condensate line is provided in a further advantageous embodiment of the invention.

The drying zone can be heated directly with superheated steam, radiant heaters and / or microwaves. Alternatively or additionally, it is also possible, the drying zone indirectly via heat exchangers and / or various energy sources, such as electricity, gas, oil, heat transfer oil and / or steam to heat. Of course, other forms of heat energy are conceivable and possible.

In order to be able to finish the drying always at the right time, that is not too early and not too late, in a further advantageous embodiment of the invention, one or more weighing devices for detecting the weight of the drying material in the drums is present. This makes it possible, by comparing the initial weight when loading the drums of the material to be dried with the current weight, to determine the mass of moisture that has been removed from the material to be dried by the drying process and to stop drying in dependence on this quantity.

An advantageous embodiment of the invention provides that the drying device has three or four drums.

A further advantageous embodiment of the invention provides that the drums are driven in rotation, so that they can be rotated, for example, during the drying process and thereby produce a better heat and moisture transfer between the material to be dried and the superheated steam, which is used for drying , This increases the efficiency of the drying process and the drying time can be reduced.

The rotary actuators can also be used advantageously in the loading station and the unloading station, for example, to position the loading opening so that in the loading station, the drum easy and example can be loaded by means of a belt conveyor. The same applies to the unloading station. There it may be desired, for example, to rotate the drums so that the loading opening is located at the lowest point of the drum. By opening this loading opening, the drum can be emptied with gravity support and the dried material to be dried can fall into an underneath trough or a mesh basket placed underneath.

The drums located in the drying zone are conveyed out of the drying zone by turning the turnstile as soon as the drying material in this drum has reached a sufficient degree of dryness. This degree of drying can be achieved, for example, after a certain drying time has expired, or it is possible to measure the decrease in weight of the drying material in the drying zone and, via this weight decrease, to determine the residual moisture still present in the drying material. Once the residual moisture has fallen below a predetermined limit, the drum can be transported out of the drying zone.

Further advantages and advantageous embodiments of the invention are the following drawings, the description and the claims removed. All features disclosed in the drawings, the description and the claims can be essential to the invention both individually and in any desired combination.

Figur 1

eine Ansicht von vorne auf ein Ausführungsbeispiel einer erfindungsgemäßen Trocknungsvorrichtung;

Figur 2

eine isometrische Ansicht des Ausführungsbeispiels einer erfindungsgemäßen Trocknungseinrichtung,

Figur 3

eine Ansicht von hinten auf das Ausführungsbeispiel gemäß der Figuren 1 und 2 und.

Figuren 4

und 5 Ausführungsbeispiele erfindungsgemäßer Fördereinrichtungen

In the drawing show:

FIG. 1

a view from the front of an embodiment of a drying device according to the invention;

FIG. 2

an isometric view of the embodiment of a drying device according to the invention,

FIG. 3

a view from the rear of the embodiment according to the FIGS. 1 and 2 and.

FIGS. 4

and 5 embodiments of inventive conveyors

In FIG. 1 an embodiment of a drying device according to the invention is shown partially cut free. Visible is a frame. This frame is surrounded laterally in normal operation and on its upper side by heat-insulating plates, so that the heat exchange between the interior of the drying device is minimized with the environment. Frame and plates form a housing 1 of the drying device. In the vertical direction, the housing 1 can be divided into an upper part 3 and a lower part 5. Between the upper part 3 and the lower part 5 there is no barrier in the form of a ceiling or a false floor. The separation of the upper part 3, which simultaneously receives a drying zone 7 and the lower part 5, which is subdivided into a loading station 9 and an unloading station 11, takes place only due to temperature and humidity differences of the steam or vapor / air mixture in the housing 1.

In the center of the housing 1, a rotatably mounted turnstile 13 with a total of four arms 15.1 - 15.4 is arranged. An axis of rotation of the turnstile 13 and a rotary drive of the turnstile 13 are denoted by the reference numerals 17 and 19.

At each of the boom 15.1 - 15.4 a drum 21.1 - 21.4 is present in each case. In the drying zone 7 are the drums 21.1 and 21.2. In these drums is the Trocknungsgut, especially laundry. The drums 21 are advantageously made of a perforated stainless steel sheet, so that on the one hand the laundry can not fall out of the drums and on the other hand, the heat transfer between the located in the drying zone superheated steam and the material to be dried is good.

As soon as the drying material located in the drum 21.2 has reached the required residual moisture and is thus sufficiently dry, the turnstile 13 is rotated clockwise by 90 ° so that the drum 21.2 reaches the unloading station 11. The previously located in the unloading drum 21.3 passes through the loading station 9 and can be loaded via a loading device 23 with wet laundry or moist Trocknungsgut. At the same time, the already loaded drum 24.1 passes from the loading station 9 into the drying zone 7.

Since there are always two drums, namely the drums 21.1 and 21.2 simultaneously in the drying zone 7, the drying time is twice as long as the loading and unloading time of the drums 21.4 and 21.3. How out FIG. 1 clearly visible, the drums 21 are formed in the form of a cylindrical hollow body. On the cylindrical part of the Drums 21 each have a loading opening 25 is provided, which is closable. When located in the loading station 9 drums 21.4 the loading opening 25 is opened and the drums 21.4 rotated so that the drum 21.4 is open at the top and can be loaded by a loading device 23 with laundry.

In the drums 21.1 and 21.2 located in the drying zone 7, the loading openings are closed, so that no laundry can fall out of the drums 21, even if they are rotated about their own axis during the drying process.

When located in the unloading station 11 drum 21.3, the loading opening 25 is open and faces down. As a result, the dried laundry located in the drum 21.3 can fall under gravity into a transport carriage 27 and be transported away.

In FIG. 2 the same embodiment is shown in an isometric view. The same components are provided with the same reference numerals and it is the respect FIG. 1 Said accordingly.

FIG. 3 shows the back of the drying device according to the invention. In this case, the left part of the drying device is covered with the side walls, while the right part is shown cut free. How out FIG. 3 As can be seen, a total of five motors 29 are attached to the frame of the housing 1. The motor 29 located in the middle serves to drive the turnstile 13, while the other motors 29 are used to drive the respective drum 21 located therebetween. The motors 29 are thus mounted stationary and do not rotate with the turnstile. It would also be conceivable, the drums 21st associated motors 29 also attach to the arms of the hub 13. However, then the supply of the motors with energy and the positioning of the drums or the loading openings 25 of the drums in the loading station 9 and the unloading station 11 would be difficult.

In an embodiment of the drying device according to the invention suitable for laundries and hotels, the heating power is about 160 kW and the cycle time is 20 minutes. This means that the four drums are moved through the turnstile 23 by 90 ° every five minutes. A drum 21 is always located in the loading station 9, another in the unloading station and two drums 21 are located in the drying zone 7.

The cooling of the laundry takes place outside the machine. When leaving the drying zone, the drums 21 are naturally also warm and cool off. This loss of sensible heat is unavoidable but very low compared to other batch dryers.

The energy efficiency of the drying device according to the invention is very good, it is calculated with savings of 30 - 70% compared to conventional dryers.

The condensate obtained in the drying of the laundry can be used in other processes, since it already has a temperature of just below the boiling point of about 70-80 ° Celsius. The condensate is recovered in the boundary region between the drying zone 3 and the lower region 5. For this purpose, cooling water is pumped through lines. On the cold surface of these pipes condenses the moisture and drips from there in arranged below the lines collecting gutters. These collecting channels open into the condensate line. This arrangement has, in addition to the condensate drainage, the function of separating the drying zone 3 from the lower region 5.

Since the entire drying zone always remains at the operating temperature, a very high efficiency is given in this area and also the performance of the drying zone 7 system is very high.

FIG. 4 shows a simplified embodiment of a particular embodiment of a rotating device for the drums 21. In this embodiment, the rotating device is designed as a toothed or impeller 31. The toothed wheel or impeller 31 is designed as an externally toothed gear and is driven via a pinion (not shown) of a drive motor, in particular a motor 29, if necessary. In this embodiment, the required torque of the motor 29 is relatively small because of the large diameter of the disc wheel 31.

In the embodiment according to FIG. 5 the drums 21 are guided in guide rails 33 on a "rectangular" path. The drive of the drums 21 takes place for example via a pull rope or a chain 35 or via toothed belt or pinion.

Claims (17)

Drying device comprising a housing (1), having at least two drums (21) for receiving the dry material, wherein the at least two drums (21) rotatably on a conveyor (13) for conveying the material to be dried in and out of a heated drying zone (7) Loading station (9) and / or an unloading station (11) are fixed, characterized in that the drying zone (7) in an upper half (3) of the housing (1) is formed, that the loading station (9) and / or the Unloading station (11) in a lower half (3) of the housing (1) are formed. Drying device according to claim 1, characterized in that the conveyor device comprises a turnstile (13), and that at the turnstile (13) for each drum (21), a boom (15) is present. Drying device according to claim 1 or 2, characterized in that a rotation axis (17) of the turnstile (13) extends substantially horizontally. Drying device according to claim 1, characterized in that the conveyor at least one conveyor wheel, in particular gear and / or impeller (), comprises, and that the drums (21) on the or the conveyor wheels () is rotatably mounted. Drying device according to claim 5, characterized in that a rotation axis of the or the conveying wheels (16) extends substantially horizontally. Drying device according to claim 1, characterized in that the conveyor device comprises rails, chains and / or toothed belt Drying device according to one of the preceding claims, characterized in that the axes of rotation (19) of the drums (21) extend substantially horizontally. Drying device according to one of the preceding claims, characterized in that the drums (21) have a closable loading opening (25). Drying device according to one of the preceding claims, characterized in that the drums (21) of a thermally insulated and at least in the upper part gas-tight housing (1) are surrounded. Drying device according to one of the preceding claims, characterized in that the drums (21) can be conveyed by turning the turnstile (13) into the drying zone (7), the loading station (9) and / or the unloading station (11). Drying device according to one of the preceding claims, characterized in that a condensate line is provided, and that condensate is removed from the drying zone (7) with the condensate line. Drying device according to one of the preceding claims, characterized in that the drying zone (7) is heated with superheated steam, radiant heaters and / or microwaves. Drying device according to one of the preceding claims, characterized in that for the Drums (21) one or more weighing devices for detecting the weight of the drums (21) located Trocknungsguts is present. Drying device according to one of the preceding claims, characterized in that it comprises four drums (21.1, 21.2, 21.3, 21.4). Drying device according to one of the preceding claims, characterized in that the drums (21) are rotatably drivable. Drying apparatus according to claim 15, characterized in that the loading opening (25) of a drum (21.4) located in the loading station (9) is positioned by rotating the drum (21.4) such that the loading of this drum (21.4) is achieved by a stationary loading device, especially a conveyor belt, can be done. Drying device according to Claim 15, characterized in that the loading opening (25) of a drum (21.3) located in the unloading station (11) is positioned by rotating the drum (21.3) such that the unloading of this drum (21.3) is effected by a stationary unloading device can.

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