EP1273691B1 - Method for washing laundry and a counter current washing machine to carry out the method - Google Patents

Abstract

Washing detergent is guided through operating chambers (2) in a reverse direction flow to laundry/items being washed. The working chamber for the treatment stage swivels in reverse around an axis of rotation during the treatment stage. In a washing chamber (8) part of the washing detergent is stored temporarily in a number of scooping pockets (20) fitted between an inner perforated drum wall and an outer wall surrounding it. An Independent claim is also included for a reverse direction flow washing machine with numerous working chambers set up to swivel around an axis of rotation in sequence in a laundry conveyor device.

Description

The invention relates to a method for washing laundry in a single-walled countercurrent washing machine, wherein the laundry is subjected in a number of successively in a conveying direction working chambers each one of these associated treatment step, wherein the washing liquor used for this purpose led in countercurrent to the laundry through the working chambers is, and wherein during a treatment step, the intended working chamber is reversely pivoted about an axis of rotation. It further relates to a single-wall countercurrent washing machine suitable for carrying out the method.

In the industrial washing of laundry, in which on the one hand a comparatively large amount of laundry is to be treated, on the other hand comparatively complex impurities are to be safely removed from the laundry, a so-called countercurrent washing machine can be used. Such a countercurrent washing machine, as for example from the DE 198 12 386 A1 is known, usually comprises a number of in a conveying direction for the laundry successive working chambers. These working chambers, which are pivotable about a common axis of rotation, are each adapted to receive a particular amount of laundry and to perform a chamber specific treatment step, such as a prewash, a main wash, or a rinse. During the washing process, the working chambers are reversibly pivoted about their common axis of rotation, that is rotated at an angle of less than 360 °, for example by 300 °. In this reversing pivoting movement, the laundry is intensively moved in the wash liquor, supported by carrier ribs arranged on the respective chamber wall.

After expiration of such a wash cycle, the laundry is spent in each case in the next direction in the conveying direction for the laundry working chamber. For this purpose, the countercurrent washing machine may comprise a conveyor spiral passing through the working chambers. For further transport of the laundry while the working chambers to a full rotation, d. H. rotated by an angle of more than 360 ° about its axis of rotation, wherein the transport device causes the further transport of the laundry in the next following working chamber. The first working chambers seen in the conveying direction of the laundry are usually designed as pre-washing chambers, the subsequent working chambers as washing chambers and the last working chambers seen in the conveying direction as rinsing chambers.

In such a countercurrent washing machine, the washing liquor is usually conducted through the working chambers counter to the conveying direction of the laundry. For this purpose, the wash liquor is fed at the output end for the laundry in the countercurrent washing machine and flows through holes in the transport device against the conveying direction of the laundry through the working chambers. At the designated as task end for the laundry feed point for the laundry, the wash liquor is then withdrawn. By such a countercurrent principle, the laundry comes during their transport through the countercurrent washing machine with increasingly clean wash liquor in contact.

Especially in the design of such a countercurrent washing machine for the treatment of comparatively heavily soiled, for example, oily laundry, a particularly high washing and rinsing performance is a design target. It is desirable to achieve a reliable washing result with the least possible use of washing water and detergents in terms of a particularly high washing and rinsing performance.

DE 1000033 shows a double-walled begenshom wash with scoops.

The invention is therefore based on the object to provide a method for washing laundry in a countercurrent washing machine of the type mentioned above, with which a particularly high washing and rinsing performance and thus in particular a comparatively low water requirement can be achieved. In addition, a particularly suitable for carrying out the method countercurrent washing machine should be specified.

With regard to the method, this object is achieved in that each pivoting cycle part of the washing liquor located in this working chamber is separated or skimmed over the pivotal movement of the working chamber spent in an upper area of this working chamber and from there again the remaining wash liquor is added.

The invention is based on the consideration that for a particularly high washing or rinsing capacity available in the respective working chamber fleet should be exploited to a particularly high degree. Therefore, the adhering to the laundry to be washed soiling should be solved with a particularly high efficiency of the laundry and brought into the wash liquor or emulsified into it. A high transfer rate of the contaminants into the wash liquor is basically possible by providing a comparatively high amount of wash liquor, ie a comparatively large amount of water. However, in order to achieve a high transfer rate when removing the contaminants from the laundry and their introduction into the wash liquor even with a relatively small amount of water, a comparatively high differential speed between wash water and laundry fibers should be provided, since such a high differential speed due to the shearing effect on the Fiber passing water in conjunction with detergents causes a particularly favorable separation of the contaminants from the respective fiber. A comparatively high differential speed between laundry and water is already achieved in existing systems in that the laundry is lifted out of the washing liquor via the entrainment means within the respective working chamber and thrown back from an elevated position into the washing liquor. An additional increase in the mechanical contributions to the washing effect is now achieved by additionally still transported in the respective working chamber, a part of the liquor in a position above the laundry to be treated and is poured from there using the gravitational acceleration on the laundry to be treated.

Such an increase in the efficiency or the flushing performance can be provided both in the actual washing of the laundry provided working chambers, ie in prewash or wash chambers, as well as in designed for rinsing the laundry working chambers or rinsing chambers.

In a single-walled working chamber, the intermediate storage of the part of the wash liquor is advantageously carried out in a number of outside the drum wall arranged scoop pockets.

With regard to the countercurrent washing machine which is particularly suitable for carrying out the method, the stated object is achieved in that at least one working chamber has a number of scoop pockets which communicate with the interior of the respective working chamber on the wash liquor side in such a way that, in a starting position, a part of the wash liquor present in this working chamber the respective scoop pocket overflows, is conveyed in this scoop pocket on the pivoting movement of the working chamber in an upper space region of the working chamber and flows back from there into the interior of the working chamber.

By means of such a configuration, a buffer storage of part of the wash liquor in a scoop pocket is made possible during a wash cycle, that is to say during the reversing swiveling back and forth of the respective work chamber. As a result of the further pivoting of the working chamber, the portion of the washing liquor stored in the scoop pocket reaches a position elevated relative to the wash and pours from there, with a corresponding increase in speed due to gravity, to the laundry located in the working chamber.

For a particularly favorable casting effect, the scoop pockets are advantageously arranged in each case on the outside of a drum wall defining the associated working chamber. In order to ensure a reliable overflow of the part of the wash liquor into and out of the scoop, in a further or alternative advantageous embodiment, one of the respective scoop pocket and the associated work chamber common partition wall element over a large area, preferably substantially completely, formed as a perforated plate. By such a configuration is particularly ensured that on the perforations in the perforated plate, a large area as needed transfer of the wash liquor from the working chamber in the scoop pocket and back is possible. On the other hand, the perforated plate ensures sufficient stability, so that the laundry to be washed is reliably retained in the interior of the respective working chamber.

The quantitative extent of the additionally achievable via the scoop pockets wash contribution or traceable to the scoop pockets increases in efficiency or washing performance are mainly due to the geometric dimensions of the scoop pockets, especially compared to the dimensions of the working chambers and the usual operating conditions in the treatment of Washing liquor, in particular by their flow rate. A particularly far-reaching increase in efficiency can be achieved by distributed in an advantageous embodiment of a working chamber distributed over its circumference about eight to twelve, preferably ten, siphon pockets. The or each scoop pocket is expediently limited in the circumferential direction of the associated working chamber by a pair of chamber plates, which form an opening angle of 10 ° to 20 °, preferably of about 15 °, based on a predetermined by the rotation axis vertex. The scoop pockets are, seen in the rest position of the associated working chamber, advantageously arranged substantially in the lower outer area.

The further transport of the laundry from a working chamber in the next in the conveying direction following working chamber can be done by any suitable means. Advantageously, however, a transport spiral which passes through the working chambers sequentially is provided for the further transport of the laundry.

The advantages achieved by the invention are in particular that an additional contribution to the differential speed between the wash liquor and laundry is provided by the enabled by the scoop pockets lifting a portion of the wash liquor to a position above the laundry and the subsequent pouring of this part of the wash liquor , As a result, the mechanical contribution to the washing result, ie the detachment of impurities from the fibers as a result of a shearing effect caused by passing wash liquor, is significantly increased in comparison to known countercurrent washing systems. In particular, the wash liquor, which in the meantime has been lifted and poured from the elevated position onto the laundry, can be assigned a new, radial speed contribution which, with a suitable geometrical design, is effectively increased compared to the prevailing axial velocity contribution, for example increased by a factor of 6 to 8. As a result, depending on the degree and type of soiling of the laundry to be washed and the composition and amount of the wash liquor used, the washing or rinsing performance can be increased by up to 60% with all the resulting savings, for example for the wash water used.

Fig. 1

schematisch eine Gegenstromwaschmaschine,

Fig. 2

im Querschnitt eine Arbeitskammer der Gegenstromwaschmaschine nach Fig. 1.

An embodiment of the invention will be explained in more detail with reference to a drawing. Show:

Fig. 1

schematically a countercurrent washing machine,

Fig. 2

in cross-section a working chamber of the countercurrent washing machine after Fig. 1 ,

The same parts are provided in all figures with the same reference numerals.

The countercurrent washing machine 1 according to Fig. 1 comprises in the exemplary embodiment thirteen working chambers 2, which are arranged successively in a symbolized by the arrow 4 conveying direction x for laundry. The first working chambers 2 seen in the conveying direction x are in the exemplary embodiment designed as prewash chambers 6. The seven further working chambers 2 following in the conveying direction x, on the other hand, are designed as actual washing chambers 8 and form the washing zone of the countercurrent washing machine 1. The last three working chambers 2 designed as rinsing chambers 10 adjoin the latter in the conveying direction x, and the rinsing zone of the countercurrent washing machine 1 follows form. Deviating from this embodiment, of course, any other appropriate number of working chambers 2 may be selected.

The working chambers 2 are each formed in the embodiment substantially cylindrical and pivotable about a common axis of rotation 12. In the working chambers 2, this one continuous, in the exemplary embodiment only indicated transport coil 14 - also known as Archimedean screw - fixed, which rotates with a rotation of the working chambers 2 with these. On the object of the countercurrent washing machine 1, a hopper 16 is further arranged, can be introduced via the washing to be washed in the x seen in the conveying direction of the first working chamber 2. At the opposite end of the countercurrent washing machine 1, the completely treated laundry is removable again. Furthermore, suitable, in the exemplary embodiment only indicated supply and discharge lines for media, steam or wash liquor are arranged on the countercurrent washing machine 1.

During operation of the countercurrent washing machine 1, laundry is fed via the feed hopper 16 into the first working chamber 2 seen in the conveying direction x. In each working chamber 2 a adapted to the respective working chamber 2 treatment step of the laundry therein is carried out during a wash cycle, wherein in the prewash chambers 6 a prewash, in the Wash chambers 8, the main wash and in the rinsing chambers 10, a rinse of the laundry. During the respective washing cycle, the working chambers 2 are reversely pivoted back and forth about their common axis of rotation 12, wherein an angle range between 270 ° and 340 ° is covered during pivoting. In this swing-like reversing pivoting of the working chambers 2, the laundry contained therein relative to the respective working chamber 2 also located washing liquor held in relative motion, so that on the one hand good mixing of laundry and wash liquor and on the other hand, a difference in speed between laundry and wash liquor is maintained. The washing result in the respective working chamber 2 is determined on the one hand by the selected operating conditions, that is, for example, by the temperature set there and by the chemical composition of the detergents used. On the other hand, the washing result is also influenced solely by mechanical effects, namely by a shearing action of the washing liquor flowing past the laundry fibers onto the impurities adhering to the laundry fibers.

For a good washing result, inter alia, to maintain a comparatively high differential speed between the laundry and the wash liquor at relatively low water content by upsetting and kneading the laundry to be washed. To favor this, are in the interior of each working chamber 2, as shown in the exemplary embodiment, only one example of the working chambers 2, driver ribs 18 are arranged. These lift during pivoting of the respective working chamber 2, the laundry contained therein out of the wash liquor and let them fall from relatively elevated position back into the wash liquor, resulting in a significant difference in speed between laundry and wash liquor.

After completion of a wash cycle, so after performing the number of reversing pivotal movements provided in rotation, a full rotation, ie by 360 °, the working chambers 2 is made about its axis of rotation 12. During this rotation causes the transport spiral 14 fixedly connected to the working chambers 2, that the laundry from each of the working chambers 2 is spent in each of the following seen in the conveying direction x working chamber 2.

In order to further increase the mechanical contribution to the washing effect and thus to further increase the washing or rinsing performance with comparatively low water requirement, a number of working chambers 2 are provided with scoop pockets 22 arranged in their outer area for the wash liquor. In the embodiment according to Fig. 1 are shown for reasons of clarity, only two working chambers 2 Schöpfaschen 22. However, such scoop pockets 22 may also be arranged on a plurality, in particular on all working chambers 2.

A working chamber 2 while the scoop pockets 22 are assigned, as in cross section in Fig. 2 is recognizable. Like from the FIGS. 2a and 2b recognizable, the working chamber 2 is configured with a single wall 50 with a single wall. At this external sockets 22 are arranged in the manner of external attachment. These are each bounded on the outside by an outer wall 52 and in the circumferential direction of the washing chamber 10 by chamber plates 54. To the interior of the rinsing chamber 10 towards the scoop pockets 22 are limited in this case by the outer wall 50 of the working chamber 2. In order to ensure a suitable wash fleet-side communication between the interior of the washing chamber 10 and the respective scoop pocket 22, the outer wall 50 of the working chamber 2 is configured in its respective scoop pocket 22 associated portion 56 as a perforated plate, so that at any time an overflow of wash liquor from the interior of the Rinsing chamber 10 in the respective scoop pocket 22 and back is enabled.

In Fig. 2a the working chamber 2 is shown in its rest position. In this position, the laundry 40 is substantially in the bottom region of the working chamber 2 at. Due to the perforation 31 of the outer wall 50, a part of the wash liquor flows in some or each of the shoebags 22, as shown in Fig. 2a represented by the hatching. In the further course of the respective washing cycle, the working chamber 2 is pivoted about the axis of rotation 12 so that the part of the washing liquor deposited in some of the drawers 22 is conveyed to a raised position in the working chamber 2 in comparison with the laundry 40. This is in Fig. 2b schematically shown with reference to a rotated about the axis of rotation 12 representation of the working chamber 2, wherein a likewise taking place movement of the laundry 40 due to the driver ribs 18 for reasons of clarity only indicated. The conveyed by the pivoting of the working chamber 2 in a raised position compared to the laundry 40 part of the wash liquor flows in this position now again from the respective scoop pockets 22, as symbolized by the arrows 58. This outflowing part of the wash liquor undergoes gravitational acceleration and finally hits at a relatively high speed on the laundry 40 located in the wash chamber 8. As a result, a comparatively high differential speed arises between the part of the washing liquor flowing out of the scoop pockets 22 and the laundry 40, so that a particularly effective washing effect is achieved.

LIST OF REFERENCE NUMBERS

1

Counter-current washing machine

2

working chambers

4

arrow

6

prewashing

8th

washing chambers

10

flushing chambers

12

axis of rotation

14

spiral conveyor

16

hopper

18

agitator

22

scoop pockets

31

perforation

40

Laundry

50.52

exterior walls

54

chamber plates

56

subregion

58

arrows

x

conveying direction

α

opening angle

Claims (9)

1. A method for washing laundry (40) in a counterflow washing machine (1), wherein the laundry (40) is subjected in a number of single-walled work chambers (2) arranged one behind the other, viewed in a transport direction (x), in each case to a treatment step associated with the respective work chamber, the washing solvent used for that purpose being guided through the work chambers (2) in counterflow to the laundry (40) and the work chamber (2) provided for that purpose being pivoted during a treatment step in a reversing manner around a rotation axis (12),
   characterized in that
   in each pivoting cycle, part of the washing solvent present in this work chamber (2) is scooped off, is taken through the pivoting movement of the work chamber (2) to an upper spatial area of this work chamber (2) and, from there, is added again to the remaining washing solvent.
2. The method of claim 1,
   characterized in that
   in a work chamber (2), the part of the washing solvent is temporarily stored in a number of scooping pockets (22) arranged on the outside wall (50) of the work chamber (2).
3. A counterflow washing machine (1) having a number of single-walled work chambers (2) arranged one behind the other, viewed in a transport direction (x) for laundry (40), and pivotable around a rotation axis (12), through which a washing solvent can flow in a direction opposite to the transport direction (x) of the laundry (40), at least one work chamber (2) having a number of scooping pockets (22) which, on the side of the washing solvent, communicate with the interior of the respective work chamber (2) in such a way that in an initial position, a part of the washing solvent present in this work chamber (2) flows over into the respective scooping pocket (22), is transported in this scooping pocket (22) through the pivoting movement of the work chamber (2) to an upper spatial area of the work chamber (2) and from there, flows back into the interior of the work chamber (2).
4. The counterflow washing machine (1) of claim 3, wherein each scooping pocket (22) is arranged on the outside of an outside wall (50) defining the associated work chamber (2).
5. The counterflow washing machine (1) of claim 3 or 4, wherein an intermediate wall element common to the respective scooping pocket (22) and the associated work chamber (2) is designed as a perforated plate over a large surface, preferably substantially completely.
6. The counterflow washing machine (1) of any of claims 3 to 5, wherein approximately 8 to 12 scooping pockets (22) are associated with one work chamber (2), distributed over the latter's circumference.
7. The counterflow washing machine (1) of any of claims 4 to 6, wherein the, or each, scooping pocket (22) is delimited, in circumferential direction of the associated work chamber (2), by a pair of chamber plates (54) including an opening angle of 10° to 20°, preferably of 15°, referred to an angle point predefined by the rotation axis (12).
8. The counterflow washing machine (1) of claim 6 or 7, wherein the scooping pockets (22), viewed in rest position of the associated work chamber (2), are arranged substantially in the latter's lower outside area.
9. The counterflow washing machine (1) of any of claims 3 to 8, having a transport helix (14) for transporting the laundry (40) from one work chamber (2) to the following work chamber (2).

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