DE102011118906A1 - Roller transportation system for e.g. complete automation of transport processes in inline wet chemical plant for manufacturing silicon solar cell, has liquid deflection device for preventing liquid movement from basin wall along roller - Google Patents

Abstract

The system (1) has a basin (4) acted upon with liquid (40) and comprising a passage (7) for a transport roller (2) in a basin wall (6). The transport roller comprises a region (8) that lies outside the basin. A liquid deflection device (13) is provided in the region of the transport roller and prevents liquid movement from the basin wall along the transport roller. A drive (3) is arranged outside the basin and connected with the transport roller. A collecting unit (15) is arranged under the deflection device for dripping of liquid from the transport roller and designed as a closed housing. The liquid deflection device is designed as a groove.

Description

The invention relates to a roller transport system, in particular a roller transport system for devices and systems for performing a wet chemical method.

It is known in the production of solar cells and PV modules that so-called roll transport systems are used in the production chain in the various manufacturing processes for transporting the semi-finished products. The solar cells and their precursors are subjected to various wet-chemical processes. Roller transport systems are used, inter alia, in wet process systems, such. B. used in plants for acid texturing, wet edge insulation or etching.

For example, the wafers in the production chain of a silicon solar cell are regularly treated with chemicals in wet-chemical processes. In one process, the wafers are cleaned, for example, in an etching bath and, inter alia, freed from disturbing sawing damage and textured. Such wet-chemical processes or individual process steps can be carried out, for example, in the inline process. In inline process, the wafers are wet-chemically treated in a basin filled with suitable chemicals and conveyed along a transport direction on transport rollers of a roller transport system through the basin.

Roller transport systems are available in various designs and enable the automation or partial automation of transport processes in such inline wet-chemical systems or inline wet benches. There are strict requirements for material handling and the reliability of roller transport systems within such systems.

In one embodiment, in-line wet scrubbers include a basin filled with a process-necessary chemical to treat the wafers or cells. In the basin a plurality of transport rollers are arranged one behind the other in order to convey thereon the products to be treated along a transport direction through the basin. Depending on the process, the products may partially or completely submerge in the process fluid. Here at the transport rollers are typically applied to the liquid or the chemicals used and / or the transport rollers are completely within the liquid. In various embodiments known in the prior art, the individual or all transport rollers are arranged so that their free, drive-side end is outside the basin and the transport rollers protrude through a pool wall passage in the basin and indeed with its basin-side transport section. The drive-side ends are connected to a drive which can rotate the transport rollers in a direction intended, so that products stored on the basin-side transport section of the transport rollers are transported in the basin in the desired direction of conveyance in accordance with the direction of rotation.

Here, different drive and transport roller configurations are used, in which the transport rollers are indirectly connected via transmission devices or directly at its drive end with at least one common or separate drive.

The roller transport systems should be sealed at their partition passages against liquid leakage, so that no chemicals can escape from the basin and external parts and drives are damaged.

The known from the prior art roller transport systems have a significant disadvantage and indeed the disadvantage of insufficient sealing of the pool wall ducts with respect to the transport rollers. It therefore happens that liquid escapes from the tank at the seals and this runs along the surface of the transport rollers to the drives. As a result, the drives are impaired in their functionality. The aggressive chemicals attack or destroy the drives or at least parts of them. This results in unpredictable and costly production interruptions and machine downtime due to repairs.

A further disadvantageous effect is that the liquid level in the inline wet plant successively decreases because of the liquid leakage, and the transport rollers and thus the products to be treated are no longer adequately supplied with chemicals. In addition, monitoring and dosing must top up the leaked chemicals, taking into account and monitoring or observing the concentration mixture of the chemicals involved in the pool.

Different improvements can be seen in the prior art as to how the sealing performance and the reliability and service life of seals in bulkhead bushings can be increased compared with transport rollers.

However, these solutions are aimed primarily at improved and optimized sealing performance, but still can not prevent damage occurring to the drives and drive units on the transport rollers. Furthermore, there is the further problem that the seals have no universal chemical resistance to the different chemicals used and also a later change to an alternative chemical in the user is limited by the execution of the seal.

The object of the invention is therefore to overcome the disadvantages mentioned and to largely prevent the negative consequences of escaping from the pool liquid and to provide a total of a more reliable and less prone roller transport system.

This object is achieved with the features of claim 1, wherein advantageous developments of the invention are specified in the dependent claims.

In particular, a roller transport system is provided, which has a transport roller, as well as a liquid-filled or liquid-actable basin which has a passage for the transport roller in at least one basin wall, wherein the transport roller has an area lying outside the basin in which at least one liquid deflecting device is provided which prevents fluid movement along the transport roller from the pool wall over this area.

The basic idea of the present invention is therefore to design the transport roller such that a fluid deflection device is provided between the pelvic wall and the drive or the drive-side end of the transport roller, which prevents fluid movement along the transport roller from the pelvic wall to the drive and the fluid by means of the fluid deflection device diverted and / or separated.

The area at which the transport roller is to be formed with a liquid deflecting device is therefore preferably offset adjacent to the drive in the direction towards the pool wall in the direction of the pool wall passage of the transport roller, thus between the drive and the pool wall at which the undesired liquid discharge is typically to be found ,

If liquid escapes from the basin, the liquid deflection device prevents the liquid from flowing along the surface of the transport roller along its outer jacket and thus to a drive. Such a liquid movement, which has a component of movement parallel to the axial direction of the transport roller, is deflected at the liquid deflecting device and ideally also detached therefrom.

Advantageously, the drive is located on the outside of the pelvic end of the transport roller, thus preferably arranged on the drive-side end of the transport roller.

In a particularly advantageous embodiment, the roller transport system has a collecting unit below the liquid deflecting device which is provided for collecting the liquid to be removed from the transport roller. This ensures that the loss of fluid in the tank is minimized and that the liquid leaked from the tank along the transport roller and diverted by the liquid diverter and deposited in the catcher unit can be collected and returned to the process.

Advantageously, the collecting unit has a collecting space and the region of the transporting roller having the liquid deflecting device is arranged inside or above the collecting space. If the area of the transport roller having the liquid deflecting device is arranged completely within the collecting space in the collecting unit, the collecting unit can be formed as a closed housing, whereby contamination with impurities can be prevented or at least clearly minimized.

As an advantageous embodiment of the invention, a recirculation unit for the leaked liquid between the collecting unit and the basin is arranged, namely for returning the Wegzuführenden liquid in the basin. Consequently, in combination with the aforementioned closed collecting unit, an optimum circulation process in terms of purity can be achieved. On the one hand so the drives and units can be protected and on the other hand, a recovery and recycling of leaking liquid and also a high degree of purity of the chemistry can be ensured in the circuit.

To increase the degree of purity, the recirculation unit may be equipped with a filter for filtering the separated liquid. The filter may be placed either directly in the recirculation unit or at a suitable position at the outlet of the recirculation unit to the recirculation unit such that the collected chemical undergoes a filtering process before being returned to the basin.

The basic principle in the formation of the Flüssigkeitsumlenkeinrichtung is to be seen in that the Flüssigkeitsumlenkeinrichtung in the form of a a liquid movement interrupting contour is introduced on or in the outer jacket of the transport roller. As a result, a fluid movement along the transport roller is deflected by the pool wall in the direction of the drive in a direction away from it and / or drained into the collecting unit. Advantageously, the Flüssigkeitsumlenkeinrichtung is formed so that the operation is independent of speed and advantageously also given at a standstill of the transport roller. In other words, such a contour is to be introduced or to be mounted in or on the transport roller such that a fluid flow emerging from the pelvis or a fluid movement along the transport roller at the contour undergoes a deflection. Advantageously, the Kontour is provided with a drip edge to collect the deflected or interrupted in the flow flow amount of liquid and drain into the collecting unit.

Advantageously, the liquid deflecting device is designed such that when the transport roller is rotated, a fluid movement from the pelvis to the drive is deflected in a substantially direction opposite to that of the drive.

This is accomplished in a preferred embodiment of the invention in that the Flüssigkeitsumlenkeinrichtung is formed as a groove in the outer jacket of the transport roller, wherein the groove is formed circumferentially in an advantageous manner as a groove in the outer shell. Alternatively, a plurality of spaced apart and / or mutually offset grooves or grooves may be formed in the outer jacket, either completely or partially circumferentially.

The formation of the groove is particularly efficient as a helical or helical groove in the outer jacket of the transport roller which is single or multiple in its shape. Turning a transport roller formed in this way causes the groove to move about the axis of rotation when the transport roller is rotated by the drive in a predetermined direction of rotation, similar to a screw-in movement of a screw. The groove promotes the liquid analogous to the functioning of a screw conveyor. According to the invention thus an undesirable movement of liquid along the surface of the transport roller and that in a direction towards the drive at a rotation of the transport roller and the associated "traveling movement of the groove" interrupted by this groove and with her in her "migration direction" from the drive led away. The deflection effect of the groove depends on the winding direction of the groove and the direction of rotation of the transport roller. The name of the winding direction follows the right-hand rule, the turn is right-handed when it winds in a clockwise direction (in the direction in which it moves away from the viewer), otherwise left-handed.

Advantageously, the attachment of the groove is chosen so that the helical or helical groove is formed in its winding direction opposite to the direction of rotation of the transport roller, such that when rotating the transport roller in the intended direction of rotation, a liquid movement along the transport roller to the drive in the substantially opposite Direction deflected and / or is deposited in the collecting unit.

The groove advantageously has a U-shaped cross section. Alternatively, however, the groove can also be introduced into the outer jacket in other cross-sectional shapes.

Furthermore, instead of a helical or helical groove, a helical or helical protruding contour can also be formed on the outer jacket.

In a further alternative embodiment, the liquid deflection device can also be formed by one or more ring elements circulating on the outside of the transport roller, wherein the ring element is arranged, for example, as an O-ring on the outer jacket of the transport roller. The ring element may be formed either in one piece with the transport roller or as separated from the transport roller on this can be applied ring element. A separable from the transport roller ring element has the advantage that it is interchangeable on the one hand and on the other hand can be removed for mounting the transport roller, so that no disturbing parts complicate the assembly.

A multi-stage or cascade-like combination of the embodiments is also conceivable, so that, for example, in addition to the helical or helical groove, one or more ring elements can additionally be arranged on the transport roller. In this way, a cascade-like liquid barrier can be formally formed for undesirable fluid movements, with which drives are safely protected even with larger leaks. Since the ring element rotates together with the transport roller, it can be sealed in a simple manner.

In a preferred embodiment, the liquid deflecting device forms a preferably circulating drip edge.

A roller transport system according to the invention can advantageously have a plurality of transport rollers equipped with a fluid deflection device, which are located within one preferably horizontal transport plane arranged in a row one behind the other and the Flüssigkeitsumlenkeinrichtungen are arranged within or above a common, preferably U-shaped collecting unit.

Furthermore, a plurality of further transport rollers can be arranged in one, the first adjacent, second transport plane above the first transport plane, which also have Flüssigkeitsumlenkeinrichtungen disposed within or above the common collecting unit.

The invention will be explained in more detail with reference to the drawings. In the drawings shows:

1 : A schematic sectional view through an inventive roller transport system;

2 : A schematic side view of a first embodiment of a transport roller with a Flüssigkeitsumlenkeinrichtung invention;

3 : A sectional view through the embodiment according to 2 along the axis AA;

4 : A schematic side view of a second embodiment of a transport roller with a Flüssigkeitsumlenkeinrichtung invention;

5 : A sectional view through the embodiment according to 4 along the axis BB.

Terms used in the following description to indicate orientation and location, such as right, left, top, bottom, etc., refer to the illustrations in the figures and are not intended to be limiting.

The 1 shows a schematic sectional view through an embodiment of a roller transport system according to the invention 1 , The roller transport system 1 has a transport role 2 and one with the transport roller 2 connected drive 3 as well as a basin 4 on. The basin 4 gets from a pelvic floor 5 and surrounding pool walls 6 formed, whereby the the drive 3 facing, right pelvic wall 6 a pelvic wall duct 7 for the transport role 2 having.

The basin 4 is with a liquid 40 so far filled that the transport role 2 inside the liquid 40 located.

As in 1 can be further seen, is the transport role 2 as a substantially cylindrical elongated roller with a roller axle 20 educated. The transport role 2 extends between a left and one of these opposing right pelvic wall 6 of the pelvis 4 and is rotatably mounted. A section 8th the transport role 2 protrudes through the wall duct 7 in the right pelvic wall 5 therethrough. Thus, the transport roller 2 one outside the basin 4 arranged area 8th and one inside the basin 4 arranged area 9 on. The transport role 2 is at a free end 10 of the area 8th with the drive 3 connected. The drive 3 is doing so with the transport role 2 coupled, that this the transport role 2 in a desired transport direction in the basin 4 can drive rotating.

The transport role 2 is in a warehouse 11 the pelvic wall duct 7 stored.

The pelvic wall passage 7 and possibly the warehouse 11 are as a sealed against liquid leakage from the tank passage for the transport role 2 educated. For this purpose, a liquid seal 12 used. If the seal 12 not fully and permanently seals, there may be an undesirable leakage of liquid 40 from the basin 4 come. This creates a like in 2 schematically indicated fluid movement 41 in which the leaking fluid 40 along a surface 21 , thus along an outer shell 22 the transport role 2 runs in the direction of the drive 3 ,

As in 1 apparent, is the outside of the basin 4 arranged area 8th the transport role 2 between the drive 3 and the pelvic wall 6 , This area 8th has a liquid deflecting device 13 on, which is a liquid movement along the transport roller 2 from the pelvic wall 6 over the area 8th prevented.

The Fluidumlenkeinrichtung 13 of the roller transport system 1 is located within a collecting unit 15 with a collection room 16 in the leaking fluid 40 be diverted and / or drained and collected in it.

In the 2 and 3 is a first embodiment of the Flüssigkeitsumlenkeinrichtung 13 shown in more detail.

In 2 is the outside of the pelvis 4 arranged area 8th with the Fluidumlenkeinrichtung 13 displayed. The Fluidumlenkeinrichtung 13 is considered a helical groove 30 in the outer jacket 22 the transport role 2 formed circumferentially. This can be designed left or right depending on the preferred direction of rotation. The 3 makes a cut through the transport roller 2 according to 2 along the axis AA. The groove 30 is in formed in the present embodiment as a groove with a U-shaped cross-section. The groove 30 also has a drip edge 31 from the edge to the of the groove 30 formed step between the surface of the outer shell 22 and a side wall 32 the groove 30 is formed.

In the 4 is a second embodiment of the outside of the pool 4 arranged area 8th with an alternative Fluidumlenkeinrichtung 13 shown. The Fluidumlenkeinrichtung 13 is here as a circumferential ring element 33 on the outer jacket 22 the transport role 2 educated. The 5 makes a cut through the transport roller 2 according to 4 along the axis BB. The ring element 33 is in this embodiment as a cylindrical ring portion to the outside of the transport roller 2 out. The ring element 33 has a drip edge facing the basin 31 from the edge to that of the ring element 33 formed step between the annular surface 34 of the ring element 33 and the pelvis facing side surface 35 of the ring element 33 is formed. Also can be seen in 4 a second ring element 33 which is adjacent to the first ring element 33 on the transport roller 2 is arranged. As a result, a two-stage Flüssigkeitsumlenkvorrichtung is formed in the event that liquid 40 passes past the first deflection. It is also possible to have one or more liquid deflection devices with a groove 30 with one or more such with ring element 33 to combine.

The collecting unit 15 is as a U-shaped tub 17 trained and has at its bottom 18 via a recycling unit 19 , Alternatively, the U-shaped tub 17 as in 4 shown also from the pelvic wall 6 and an L-shaped catcher unit 15 be formed. The L-shaped catcher unit 15 is with advantage directly with the pelvic wall 6 connected. In this case, forms a leg of the L-shaped collecting unit 15 the ground 18 and the other leg a side wall of the collecting unit 15 ,

The feedback unit 19 is with the pelvis 4 connected, so that in the collection room 16 the collecting unit 15 collected liquid 40 in the basin 4 can be returned. The feedback unit 19 has a filter 24 on top of that in the collection room 16 collected liquid 40 cleans or filters before returning to the basin. The collecting unit 15 is with a lid 25 closed and thus forms a circumferentially closed housing for the Flüssigkeitsumlenkeinrichtung 13 , In the area of the recirculation unit 19 may optionally be another processing unit for the liquid 40 be provided.

In operation, the substrate is so through the basin 4 to transport it in contact with the liquid 40 comes. Insufficient sealing causes liquid to run during operation 40 from the basin 4 and moves along the transport roller 2 , At the Fluidumlenkeinrichtung 13 becomes the exiting liquid 40 diverted and drained. This will be the drive 3 protected. The drained liquid 40 will be in the collection unit 15 collected and possibly processed and returned to the process via the return unit. Alternatively, disposal of the collected liquid 40 respectively.

There are described preferred embodiments, but an exchange or the combination of single or multiple features or deviating designs are possible. So z. Example, an upper transport roller may be provided as Niederhauer for a substrate and, if appropriate, this may also be provided with a Flüssigkeitsumlenkeinrichtung. It is also conceivable to provide both ends of a transport roller with liquid deflection devices and in particular to arrange a series of transport rollers within a transport plane one behind the other.

Furthermore, the roller transport system can have a plurality of second transport rollers of opposite direction of rotation in one, to the first adjacent, second transport plane above a plurality of first transport rollers and these also have a Flüssigkeitsumlenkeinrichtungen. These can be arranged together with the Flüssigkeitsumlenkeinrichtungen the lower transport rollers within or above a common collecting unit. The first and second transport rollers can be driven by a common drive, wherein between the two a mechanical coupling can be provided to transmit a rotational movement of a transport roller to the other. In the region of the passage, a seal for the transport roller and / or a bearing unit, in particular a ball bearing for the transport roller, can be provided.

LIST OF REFERENCE NUMBERS

1

Roller transport system

2

transport roller

3

drive

4

pool

5

pelvic floor

6

pelvic wall

7

Beck wall bushing

8th

Area of transport role outside the basin

9

Area of transport role within the basin

10

free drive end

11

camp

12

liquid seal

13

liquid deflector

15

Auffangeinheit

16

plenum

17

tub

18

ground

19

Return unit

20

roller axis

21

surface

22

outer sheath

24

filter

25

cover

30

Groove / slot

31

drip

32

Side wall

33

ring element

34

ring surface

35

side surface

40

liquid

41

fluid movement

Claims (15)

Roller transport system ( 1 ) comprising: a transport roller ( 2 ) and a tank ( 4 ), which in at least one pool wall ( 6 ) an implementation ( 7 ) for the transport roller ( 2 ), wherein the transport roller ( 2 ) one outside the basin ( 4 ) area ( 8th ) and in this area ( 8th ) at least one liquid deflecting device ( 13 ) is provided which a liquid movement along the transport roller ( 2 ) from the pelvic wall ( 6 ) via the liquid deflecting device ( 13 ) prevented. Roller transport system ( 1 ) according to claim 1, further comprising outside the basin ( 4 ) with the transport roller ( 2 ) connected drive ( 3 ) and the area ( 8th ) with the liquid deflecting device ( 13 ) between the drive ( 4 ) and the pelvic wall ( 6 ) is provided. Roller transport system ( 1 ) according to one of claims 1 or 2, wherein a collecting unit ( 15 ) below the liquid deflector ( 13 ) for that of the transport roller ( 2 ) dripping liquid ( 40 ) is provided. Roller transport system ( 1 ) according to claim 3, wherein the collecting unit ( 15 ) inside via a collecting space ( 16 ) and the liquid diverter ( 13 ) ( 8th ) of the transport roller ( 2 ) within or above the collecting space ( 16 ) is arranged. Roller transport system ( 1 ) according to one of claims 3 or 4, further comprising a recycling unit ( 19 ) between the collecting unit ( 15 ) and the pelvis ( 4 ) is arranged. Roller transport system ( 1 ) according to claim 5, wherein the recycling unit ( 19 ) a filter ( 24 ) having. Roller transport system ( 1 ) according to one of claims 2 to 6, wherein during rotation of the transport roller ( 2 ) a fluid movement from the pelvis ( 4 ) to the drive ( 3 ) by means of the liquid deflecting device ( 13 ) in the direction of the pool wall 6 is effected. Roller transport system ( 1 ) according to one of claims 1 to 7, wherein the liquid deflecting device ( 13 ) as a circumferential groove ( 30 ) in the outer jacket ( 22 ) of the transport roller ( 2 ) is trained. Roller transport system ( 1 ) according to claim 8, wherein the groove ( 30 ) as a helical or helical groove in its shape 30 ) in the outer jacket ( 7 ) is formed, and the helical or helical groove ( 30 ) in its winding direction opposite to the direction of rotation of the transport roller ( 2 ) is formed such that when rotating the transport roller ( 2 ) in the intended direction of rotation, a liquid movement along the transport roller ( 2 ) from the pelvic wall ( 6 ) in the direction of the drive ( 3 ) deflected in the substantially opposite direction and / or in the collecting unit ( 15 ) is drained. Roller transport system ( 1 ) according to one of the preceding claims, wherein the liquid deflecting device ( 13 ) at least one of the transport roller ( 2 ) radially projecting, circumferential annular element ( 33 ) having. Roller transport system ( 1 ) according to any one of claims 1 to 10, wherein several are provided with a liquid deflecting device ( 13 ) equipped transport rollers ( 2 ) are arranged in the same direction of rotation one behind the other and the Flüssigkeitsumlenkeinrichtungen ( 13 ) within or above a common capture unit ( 15 ) are arranged. Roller transport system ( 1 ) according to one of claims 1 to 11, wherein further in a, to the first adjacent, second transport plane above the plurality of first transport rollers ( 2 ) several second transport rollers ( 2 ) are arranged opposite direction of rotation and these Flüssigkeitsumlenkeinrichtungen ( 13 ), each within or above the common capture unit ( 15 ) are arranged. Roller transport system ( 1 ) according to claim 12, wherein the first and second transport rollers ( 2 ) are driven by a common drive and between the two a mechanical coupling is provided to a rotational movement of a transport roller ( 2 ) to transfer to the other. Roller transport system ( 1 ) according to one of the preceding claims, wherein in the field of implementation ( 7 ) a seal to the transport roller ( 2 ) is provided. Roller transport system ( 1 ) according to one of the preceding claims, wherein in the field of implementation ( 7 ) a bearing unit, in particular a ball bearing for the transport roller ( 2 ) is provided.

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