DE3019363A1 - Automatic liq. filter having intermittently moving filter belt - ascending from tank to remove filtered solids eliminates vacuum drum difficulties - Google Patents

Abstract

Filter comprises a guide system by which a continuous a band of filter material is drawn from a storage roll, guided downwards into a tank and then up again round the guides to leave at the top; the filter material is intermittently moved forwards by a stepping drive and the filtrate is extracted from a chamber connected to the suction side of a pump by a pump intake. This filter chamber has a perforated wall to support the ascending side of the filter belt. The pump has a valve system to enable the suction pressure to be intermittently relieved so that there is no pressure difference across the belt and perforated plate and the belt is released from the perforated plate. Preferably, the perforated zone of the plate is narrower that the total width of the filter material so that a zone free of dirt is produced at each edge of the filter belt; the stepping drive mechanism comprises a roller around which the belt passes and a pair of slender counter-rolls acting on the opposite side of the filter belt only in these clean edge regions. The difficulties of vacuum drums do not arise. There are no special sealing problems. A high throughput of liq. and efficient filtering are achieved with an economical plant. The filter band is accommodated in a very small space at the end of the tank.

Description

Automatic filter system for filtering

of liquids The invention relates to an automatic filter system for filtering out impurities from a liquid bath.

In the previously known filter systems for filtering liquids, those with a continuous path of filter material work, either a pressurized, liquid-tight housing is required, which is cleaned and cleaned every time when moving the bahnförrioen filter material must be opened, or e # in secondary evacuation system to remove the at the Surface of the filter material aesanmelten impurities. For example, describes U.S. Patent 3,497,063 discloses a filter system in which a sheet of filter material is incremental advances through a pressurized housing consisting of an upper and a The lower shell is built up and opens when the filter material is moved on and are then closed during the filtering process.

In this known system, before opening the shells of the pressure housing a torment-the same required, while ar.-on the other hand when closed Shells of the pressure housing -a seal is effected by the filter material. Furthermore, US Pat. No. 3,305,094 describes a vacuum filter in which the liquid through a horizontal piece of filter material immersed in the liquid bath is sucked in, whereby the filtered-out impurities are on the underside of the immersed filter material. In this sster, the weighting of the The flow of liquid through the filter material is periodically reversed, only those that have been filtered out Loosen impurities from the 'filter material, so that the impurities ar Can settle the bottom of the Fltissiakêitsbad to be filtered. The sunk impurities are then partially in the liquid bath with the help of a submerged mechanical conveyor removed from the liquid bath. With this filter system, not only a secondary cleaning system is required, namely, backwash facilities and mechanical conveyors; much more Impurities that have already been filtered out can also be reintroduced into the liquid to be filtered and must then be filtered out of this again.

There are also known filter systems with Unterdrucktrornrieln which a large rotating drum is partially immersed in the liquid to be filtered and has a closed loop of filter material on its surface, which continuously into the liquid into which the drum is partially submerged is immersed in order to emerge from the liquid again at another point. the In such a system, filtered out impurities are removed at the point at which the filter material emerges from the liquid to be cleaned, so that the filter material can then immerse again in the liquid bath. In the known system are inside the rotating drum in the circumferential direction a plurality of sealed chambers arranged, which have suitable Ventileinrichtuncren are connected to a vacuum source, the vacuum in each case in the in the liquid immersing chambers is effective. Filter systems with such vacuum drums are complicated and very expensive to manufacture, as shown for example U.S. Patents 3,143,502 and 3,347,389.

Based on the prior art, the invention is based on the task of to provide an improved automatic filtration system that removes contaminants from a liquid bath in a single-stage filter process with comparative Ether speed can be removed without the need for use a secondary pommel system or the like would be required.

This task is carried out by an automatic filter system of the type described at the beginning Type solved, which is characterized by the features of the characterizing part of claim 1 is.

There is a significant advantage of the filter system according to the invention in the fact that it works extremely effectively and that it is manufactured and it is very economical to operate, as there are none apart from the filter material itself Immerse material parts in the liquid bath.

It is also an advantage of the invention that a high liquid throughput can be achieved without affecting the respective effective area of the filter material a point in time would have to be sealed off in a complicated manner. In this A particular advantage of the invention lies in the fact that for the filter material no liquid-tight housing is required and there is also no auxiliary power source is needed to clean such a housing before advancing the filter material. This also results in very simple operating cycles.

It is also advantageous that the automatic filter system according to the invention is very reliable in operation and unattended during long periods of operation can run. The filter system is also extremely safe, # without that special safety precautions would have to be taken, especially because not an overpressure is used and because in the event of a power failure or other Disturbances also no risk of spilling or overflowing the to be cleaned, if necessary strongly corrosive liquids.

It is also advantageous that the filter system according to the invention can be made very compact, so that it only requires a very small amount of space and in spite of the high flow rates even under very cramped conditions can be installed.

Another advantage of the filter system according to the invention is that that with himself extremely strongly corrosive liquids including strong acids can be filtered while still ensuring a long service life is.

In particular, the filter system is also suitable for filtering Electroplating solutions.

Furthermore, it is an advantage of the filter system according to the invention, that the filter material can be used very effectively so that, if at all, only very poor unused areas of the web-like filter material occur.

Another advantage of the filter system according to the invention is that that gases which are dragged out of the liquid to be filtered or due to the operating conditions are automatically removed, so that the dangers for pump failure are significantly reduced.

Furthermore, it is favorable that the filter material is continuous or can advance intermittently at any desired speed, always only a minimal drive energy is required. In addition, depending on the conditions of use the most varied types of web-shaped filter materials are used.

Further details and advantages of the invention are provided below based on drawings and / or are the subject of subclaims. 1 shows a perspective illustration of a preferred embodiment a filter system according to the invention; Fiq. 2 one-vertical Section through the filter system according to FIG. 1 along the line 2-2 in this figure; Fig. 3 shows an enlarged section through the filter system according to.

Fig-. 2 taken along line 3-3 in that figure; Fig. 4 is a schematic Representation of a control circuit for the automatic filter system according to FIG. 1 - 3; 5 shows a vertical partial cross-section through a modified embodiment a filter system according to the invention and Fig-. 6 is a schematic representation a further modified embodiment of a filter system according to the invention.

In detail, the drawing shows a filter system 10 for removal of # particulate, solid or semi-solid matter from a liquid 11 in a tank 12. The liquid 11 can, for example, be an electroplating solution be, for example a sulfuric acid solution with nickel salts, as they are usually is used for electroplating nickel, such a liquid must be continuously filtered to filter out particulate matter and so ensure that the items to be plated have a smooth, shiny finish Surface preserved. The filter system 10 is not only for removing particulate matter Suitable for solids but also for removing flaky, gelatinous and pasty substances, etc. The filter system 10 has a pump 13 with which Help liquid 11 from tank 1-2 through a continuous belt of filter material 14 is carried out, eliminating the unwanted contamination from the filtered Liquid must be removed. To prevent the filter material 14 from clogging will, will be one after the other new lengths of the filter material 14 from a supply roll 15, which is stored in two brackets 16 and 17, into the filter system moved in.

The filter material 14 is drawn in with the aid of a drive motor 18 carried out, the via a chain or Piemen drive 19 with two take-off rollers 20, 21 is connected, which grasp the web-shaped filter material 14 and pass it through unplug the filter window 10 when the motor 18 is on.

In detail, the rotor 18 drives in via a reduction gear 23 Chain wheel, which - via a toothed belt 19 with an upper chain wheel 24 in drive connection stands. The chain wheel 24 in turn drives two gear wheels 26 that mesh with one another and 27, which are on the outside of a side plate 28 in which one ends of the Draw-off rollers 2, 21 are mounted, are rotatably connected to these ends. the other ends of the take-off rollers 20, 21 are supported in a side plate 29.

The lower take-off roller 20 has an aerandelte jacket surface with which they can grasp the relatively clean underside of the filter material 14, and rotates around a fixed axis, which is supported by two bearings 30 and 31 in the side walls 28 or

29 is defined. The upper take-off roller 21 has a relatively thin, wave-shaped middle part, which is at a distance from the knurled outer surface the lower take-off roller 20 is located, so that the impurities that are on the Top of the filter material 14 have collected the gap between the draw rollers 20 and 21 can pass freely. The take-off roller has at its outer ends 21 areas 21a and 21b of larger diameter, which have a knurled surface own and detect the longitudinal edges of the web-shaped filter material 14 to this to pull through between the Abzuaswalzen 20, 21. As shown in FIGS. 1 and 3, detect the areas 21a and 21b preferably only the edge areas of the filter material 14, on which no impurities were deposited.

So that the co-operating lateral surfaces of the take-off rollers 20, 21 are pretensioned against each other (in order to grasp the filter material 14), while the take-off rollers can still be # easily separated from each other (for threading new filter material) the upper roller rotates around an axis that is in turn pivotable about two pivot axes 32, 33. In detail are the ends the roller 21 qelaqert in the free ends of two levers 34, 35, the lower ends of which pivotable in the area of the pivot axes 32 and 33 on the side plates 28 and 29, respectively are attached. The lower ends of the levers 34, 35 are, as FIGS. 1 and 2 show, biased in the counterclockwise direction by means of springs 36 and 37, whose. other end is attached to the respective side plate 28 and 29, respectively. Based on these The draw-off roll 21 is drawn against the draw-off roll 20 in such a way that the web-shaped filter material i4 of the take-off rollers 20, 21 reliably detected and is transported, while there is still the possibility of the roller 21 of the Pull away roller 20 when the filter material becomes jammed between the two rollers or when a new web of filter material has to be threaded. The spring preload is adjustable so that the contact pressure between the take-off rollers 20 and 21 or the pressure at the two ends of the rollers can be adjusted, whereby it is ensured that the filter material 14 is drawn off aerade. Like Fig. 1 3 and 3 show, the shaft of the movable upper take-off roller 21 passes through one Slot -38 in the side plate 28 so that the gear wheel is on the outside of the shaft 27 can be attached, while the slot 38 the pivoting movement of the levers 34 and 35 allows.

Inside the liquid bath of the liquid to be filtered runs the sheet-like filter material around a recessed hollow filter cell 40, which has a perforated wall 41 which serves to hold a predetermined length of the filter material 14 while allowing liquid to pass through the filter material flows through. The liquid filtrate, which the filter material 14 and the perforated r.?and 41 has passed the filter cell 40, arrives in a collecting duct 42 inside the filter cell. The filtrate is discharged from the collecting chamber 42 via two outlet openings 43 and 44 withdrawn, which are connected to a manifold 45, which in turn is connected to a suction line 46 on the suction side of the pump 13. the Pump 13 thus draws the liquid to be filtered through the filter material 14 and the perforated wall 41 into the collecting chamber 42 and from there via the outlet openings 43 and 44 and the manifold 45 to the suction line 46.

The collection chamber 42 of the filter cell must face the liquid bath be sufficiently sealed so that the liquid 11 with the aid of the pump 13 is primarily sucked through the perforated wall 41, at the same time the filter material 14 is drawn firmly against the outside of the perforated wall 41 so that any liquid entering through the perforated wall first the filter material 14 must pass. An advantage of the considered filter system is, however, that the collecting carmer 42 of the filter cell at the impact points their outer walls etc. not fully cork must be impermeable to liquid, as the entire Filter cell 40 is sunk into the liquid bath, so that smaller leakage currents, which enter the filter block are of no importance.

It has also been shown that minor leaks tend to to close by itself, as it clogs with the dirt to be filtered out will.

More importantly, however, the length of the scope of the the portion of the filter web used in each case does not require a liquid seal because the pump does not push the liquid to be filtered through the filter material, but through the # sesauqt. So there will be a negative pressure drop across the filter medium used to pass the liquid through the filter medium to leave, so that it is not necessary, -pressurized liquid to be sealed on the inlet side of the filter material.

Furthermore, the system is extremely safe as there is no high pressure whatsoever can. In fact, the maximum pressure in the filter system is determined by the liquid level determined in the tank 12. The use of a sunken filter cell thus leads in connection with the suction of the pump to create a negative pressure drop across the Filter material for sucking through the liquid to an extremely simple, economical and safe construction, while on the other hand a relatively high one Liquid throughput is made possible. For example, it has been shown that a liquid throughput of up to about 4540 liters per hour with the considered Filter system can be achieved with a filter cell, in which the perforated wall 41 only has an area of about 65 cm2. So there is an extreme compact design despite relatively high flow rates.

The filter system 10 shown in the drawing is the filter cell 40 made of three flat plates 50, 51 and 52, the plate 50 being the perforated Wall 41 forms, while the plate 51 limits the collection chamber 42 and the plate 52 forms the rear wall of the filter cell 41 and the Sairmel chamber 42. The three plates lie one above the other and are along the circumference of the filter cell 40 by means of several Screw 53 connected, the threaded shafts of the screws 53 in the rear Plate 52 are screwed in, the trend Heads of screws in the top of the front plate 50 are countersunk. The plates 50 to 52 can taking into account the corrosive or other properties of the filter to be filtered Liquid can be made of any suitable material. If that Filter is used, for example, to filter acids, as is usually the case are used for electroplating, then the plates are preferably made made of polypropylene or a similar polyregen material, which is opposite to the strongly corrosive effect of electroplating solutions is resistant.

It is particularly advantageous to have the filter cell 4Q in the liquid bath Suspend vertically, as in this case the recessed part of the filter system is from added a narrow space between the vertical side walls of the tank 12 can be. For example, when the filter is used on an electroplating tank in which racks with a few hundred or thousand workpieces to be plated then the space inside the tank is very limited. The recessed part of the filter system according to the invention can, however, be different from the narrow one ZaZischen space can be included, which is usually a width of only 5 to 8 cm and which is provided adjacent to the walls of the electroplating tank. If there is not enough space in the tank 12 to accommodate the filter this can be taken up by a small auxiliary tank on the long side of the main tank or siphon, with the liquid via a siphon / from the main tank in the auxiliary tank is directed so that irrimer no higher fluid pressure arises as the pressure specified solely on the basis of the r.i: ll level in the tanks. In the case of a filter system with an auxiliary tank, the filtrate required by the pump 13 is normally returned to the main tank.

It is also advantageous that the outlet openings 43 and 44 at the top End of the filter cell 40 are provided. This is because this creates the possibility created that carried away Gases emanating from the liquid rise in the collecting chamber 42, continuously via the outlet openings 43 and 44 are withdrawn from the filter cell 40. Because the gases are lighter than that Liquid they pass through the suction line 46 and the pump 13 and can on the Exit the pressure side of the pump together with the filtrate and escape into the atmosphere, so that the delivery rate of the pump is not impaired by air accumulation can be.

For guiding the web-shaped filter material 14 from the supply roll 15 to the submerged filter cell 40 and from there to the extraction rollers 20 and 21 Inas des naufweges the filter web several guide elements are provided around the friction as small as possible. When the filter web leaves the supply roll 15, it first runs under a guide rod 60 and then upwards lengthways the outside of the side wall of the tank 12 to a guide roller 61.

Behind the guide roller 61, the filter web runs horizontally over the Upper edge of the tank wall away and then over another guide roller 62 downwards to the filter cell 40.

The middle part of the lower end of the filter cell 40 is now set back and provided with a rounded guide surface 63 that a lateral Guidance for the filter web results and also a smooth guide surface. At the top At the end of the filter system, the filter web runs over a guide roller-64 on the output side, before they move into the nip between the two driven feed rollers 20, 21 entry. The filter web is noticeable on the outlet side of the take-off rollers 20 and 21 an outlet chute 65 and slides along this down into a waste container 66. A plurality of protruding ribs 67 are preferably provided on the outlet chute 65, which run in the longitudinal direction of the slide and prevent the filter material 14 gets stuck on the slide.

From the drawing it is also clear that all for the function of the filter system 10 essential elements mounted on a saddle-like frame which hangs over the tank wall, with two on the inside of the tank wall downwardly hanging legs 70 and 71 are provided, while on the outside the tank wall two downwardly hanging legs 72 and 73 are provided. The inner ones Legs 70 and 71 carry the filter cell 40 and the laminate line connected to it 45. The outer legs 72, 73 carry the supply roll 15, the drive motor 18 and the pump 13. The two pairs of legs 70, 71 and 72, 73 are in the upper part the saddle-shaped frame connected by a horizontal, channel-shaped element 74, which rests on the upper edge of the tank wall. The upper ends of the legs 70 to 73 are also connected to the side plates 28 and 29, which are the guide rollers 61, 62 and 64 and the take-off rollers 20 and 21 carry.

To increase the stability, several adjusting screws 75 are provided, which, starting from the inside of the outer legs 72 and 73 on the Support the outside of the tank wall and several spacer elements 76, which are based on from the inside of the legs 70 and 71 on the inside of the tank wall.

The satelartiae approach of the filter system leads to a compact structure on both sides of the tank wall. In this way it is achieved that the components, which are mounted on the look of the legs of the frame, generally at most etna protrude 60 cm over the outside of the tank wall, so that the space requirement on the outside of the tank wall, where there are often running areas between different Tanks are located, is relatively qering. In addition, the filter system 10 takes the tank wall in the horizontal direction only at a low height, and with conventional electroplating systems typically at a height of at most about 60 cm.

To reduce the energy requirement for driving the web-shaped Filter material to a minimum and to avoid tearing of the filter material control devices are provided that switch off the pump every time the Drive motor 18 is switched on to a new length of the filter material 14 to pull over the perforated wall 41 of the filter cell 40. This is how it becomes possible to continue the filter material 14 with a very low driving force pull, because the suction force, which the filter material close to the perforated wall the filter cell holds, is canceled by switching off the pump 13. Consequently A relatively small drive motor is sufficient for transporting the filter material, which uses only a small amount of energy every time it is switched on. In addition, the drive motor must never work against the suction force, which the Filter material pulls against the filter cell 40 as long as the pump 13 is working, so that also has a lower likelihood of tearing the filter material exists in the nip between the take-off rollers 20 and 21 when the drive motor 18 is switched on. It is even more advantageous if the drive motor 18 after after switching off the pump 13 is switched on with a delay in order to ensure that that in the meantime a pressure equalization has taken place and no suction force is effective anymore is.

Deviating from the example described above, there is the locality, to let the drive motor 18 for the filter material 14 run continuously, if the liquid to be filtered does not require high suction power, or when the contaminants that are on the outside of the filter material collected and / or the structure of the filter material does not lead to this is pulled too strongly against the filter cell 40 when the pump 13 is running. In the Cases in which a continuous withdrawal of the filter material is possible, results the advantage that the filter material is used more effectively than the entire Area of the filter material over the staggered field of bffnun «s in the perforated The plate of the filter cell moves away while the pump is running, i. H. during a Filtration takes place.

Furthermore, in some cases it is advantageous to use the filter material 14 to progress gradually with stride lengths that are shorter than the Height of the filter cell 40, in order in this way an optimally effective use of the filter material to reach. (> nn for example the path of the filter material at each step only advances by a third of the height of the filter cell, then the filter cell is during every phase of operation in which the pump is working, covered with filter material, which has a graduated filter effect. In detail is in the case under consideration a third of the filter material is very fresh, while the second third is just the takes part in the second filter cycle and therefore a relatively thin layer of dirt trt, which already noticeably reduce the porosity of the filter material. Fin Another third of the "active" filter material, however, is already in its third Filter cycle used so that there was a denser layer of debris entered, which further reduce its porosity. Also with this procedure for the Advancing the web-shaped filter material results in a more effective use of the same, there is an extra percentage of the area of the filter material to cover with openings in the perforated wall of the filter cell is placed because each Section of the web-shaped filter material at three different points along the surface the perforated wall is used. That gradually Advance of the filter material takes place essentially in undefined Steps and not with exact synchronization with regard to the center-to-center distance superimposed openings so that those areas of the filter material those with openings during one cycle will normally align in the next cycle do not re-align with openings in the perforated wall, so that the filtered out Dirt matter distributed fairly evenly on the surface of the filter material will. If desired, the incremental advancement of the filter material can also be controlled exactly in such a way that it is ensured that in the case of successive Steps in each case other areas of the filter material to cover with the openings the perforated wall of the filter cell #.

Fig. 4 shows an advantageous electrical control circuit for the considered filter system 10. In the control circuit, the pump 13 is the alternating voltage from a source 80 via a contact 81a of a single-pole changeover switch 81 and via a normally closed, manually operated pushbutton shoulder 82 supplied. during predetermined time intervals, which are from in the time holding motor 83 are determined, a cam 84 driven by this sets the switching arm of the Switch 81 to a contact 81b, whereby the pump 13 is switched off and on Time relay 85 is turned on. After a previous delay, which is fixedly predetermined for the relay 85 used, its pelais contacts close 85a, so that the mains voltage is applied to the drive motor 18 for the web-shaped filter material is created. As explained above, the delay time ensures that the drive motor 18 is not switched on before the filter medium is removed from the caused by pump 13 suction is free. The filter material now wriggles during a time interval, which is determined by the speed of the timer motor 83 and the shape of the cam 84 is given is . At the end of this time interval the switching arm of the switch 81 returns to the contact 81a, whereby the Relay 84 drops out, so that the motor 18 is switched off.

On the other hand, the pump 13 is switched on again. This is a Duty cycle finished. The duration of each cycle as well as the duration of each Phases of each cycle (e.g. the duration of the pumping phase, the delay time and the transport time for the filter material) can be set so that that this time or these times correspond to the respective conditions of use of the filter system correspond. For example, a number of different time aes are available in commerce expensive switch available, which different setting devices for the Change the time intervals for which the switch in its individual Positions remains. There are similarly commercially available delay relays, where literally any delay time can be set. if it is desired to interrupt the control by the changeover switch 81, the Push button switch 82 manually depressed to a second pair of contacts to connect, which has the same effect as flipping the switch 81 is achieved on the contact 81b.

Fig. 5 shows a modified embodiment of a filter system according to the invention, at which the angle at which the filter cell 40 relative to the Liquid surface is inclined, is adjustable. The legs are used for this purpose 70, 71, which carry the filter cell 40, in the area of a pivot axis 90 schv hinged on the side plates 28, 29 and no longer, as in the first embodiment, rigid on these plates or

attached to component 74. In this way the possibility arises the portion of the filter system 10 carried by the taverns 70, 71 to remove the horizontal pivot axis 90 of the legs 70, 71 to pivot, the pivot axis 90 preferably together with the axis of rotation of the guide roller 64; - # llt.

The pivotable attachment of the legs 70, 71 opens up the possibility of the filter cell 40 can be easily pivoted out of the liquid 11, whereby the Threading a new web of filter material 14 is facilitated without having to the entire filter system would have to lift out of the tank 12. Also, you can due to of pivoting mounting the perforated wall 41 of the filter cell 40 below each Align the desired angle, thereby filtering the withholding of certain types of ausa « Contaminants on the filter material when it is pulled out of the liquid 11 is facilitated. For example, some types of waste materials are very slippery and have a tendency to slide down the filter material when the The suction effect of the pump 13 stops and these contaminants no longer adhere to the filter material holds on.

Due to a flatter angle of adjustment 40 of the filter cell compared to the Horizontals can, for example, as shown in dashed lines in FIG. 5 is, certain types of slippery contaminants are trapped by the filter material and thus removed from the liquid 11.

If the filter system according to FIGS. 1 to 5 with high flow rates operated, the pump used in the system can take a relatively short time Life expectancy result, especially if the liquid to be filtered has a has increased temperature. It has now been shown that in these cases the The life expectancy of the pump can be increased considerably if this is modified System according to Fis. 6 begins. In this system, the pump 100 is below # the Filter cell 14 mounted and connected to the lower end of the same via a suction line 101 connected, which is passed through the bottom of the tank 12. The suction line runs along its entire length either horizontally or downwards in the direction to the inlet side of the pump 100, so that # s the pump is already under the action of the Gravity filled with the liquid flowing down from the cell 14 will. To increase the life of a rotor 100a, which the Pump 100 drives, the pump 100 is preferably operated continuously, which is why a valve 102 is provided in the outlet line 103 leading away from the pump.

If now the filter material over the perforated wall of the filter cell 14 is blocked and should be moved further, the valve 102 is closed, to cancel the suction on the filter material so that it moves on can be until a new length of the filter material web over the filter cell 14 is located. The pump 100 continues to run, but continues to generate the valve for as long 102 remains closed, no suction force acting on the filter material. When the filter material has then advanced, the valve 102 is opened again, so that the pump 100 can deliver liquid again, the filtrate via a Return line 100 is returned to the tank 12 or another vessel.

Even with a suction line 101 which, according to FIG. 6, is a gravity flow to the pump 100 allows between the filter cell 14 and the pump 10 steam resp.

Castaschen result when the filter material is clogged.

For example, the one generated by the pump in the suction line 101 Negative pressure cause the liquid located there to boil, especially burning heated liquid is used. Such gas bubbles can, however Result in failure of the pump. To avoid this problem, the return line is 104 connected via a second valve 105 to a bypass line 106, via the liquid can flow from the return line 104 to the suction line 101 while the valve 102 is closed, removing all gas bubbles from the suction line 101 through the filter cell 14 can escape. If so then the valve 102 opens again, a steady flow of liquid is fed to the # pump 101, in which there are no gas or air bubbles that could lead to malfunction could. The valve 105 is closed at the same # time that the valve 102 is opened and can also simultaneously with the closing of the valve 102 be opened.

In the special arrangement shown in FIG. 6, the valves 102 and 105 controlled by a vacuum switch 107 and by the same timer switch 108, which also controls the drive motor 18 for the filter material. In detail the vacuum switch 1Ö7 closes the valve 102 and opens the valve 105 when the pressure in suction line 101 drops to a level which indicates that the filter material is so dirty or clogged that it needs to be changed should.

The timer 108 also receives a signal from the vacuum switch 1-07 and then initiates the advancement of the filter material by switching on the motor 18 a. After a predetermined time interval, the timer 108 switches off and transmits a signal to valves 102 and 105, whereby valve 102 reopens and the Valve 105 is closed. At the end of the specified time interval, the Timer 108 also switches off the drive motor 18. If desired, you can the two valves 102 and 105 can be replaced by a single three-way valve.

As is clear from the preceding detailed description, leads the invention to an improved automatic filter system, with the help of which - Contamination can be removed from a liquid on the filter material itself can without any additional facilities for the removal of the filtered out Contaminants would be required. Included the system cooperates high speed. The filter system is effective and economical to manufacture and to operate, since apart from the filter material itself, no moving parts are provided that are immersed in the liquid bath. Furthermore, a high liquid throughput is achieved achieved without having to go around the effective area of the filter material at any point in time a liquid seal would be required and without A liquid-tight housing would be required for the filter material.

In this context it should also be noted that there is no need for a secondary Energiecruelle to clean the filter housing before further transport of the filter material, so that the operating cycles are very simple. Included the automatic filter system according to the invention is extremely reliable in operation and can work automatically for long periods of time without maintenance. The filter system works safely without any particular security problems and can in particular be operated in such a way that neither an overpressure nor the There is a risk of spillage of corrosive liquids in the event of failure the supply voltage or another fault occurs. The filter system is also extremely compact so that it can be mounted in a very tight space, which means that it can be Use in even the tightest of factories is made possible, while the desired high filter speed chains are made possible. The filter system can can also be easily made from materials, their use even in Filters extremely corrosive liquids including strong acids is problem-free, with a long service life being achieved. In particular the filter system is useful for the filtration of corrosive electroplating solutions. Furthermore, the filter material can be effective in the filter system according to the invention exploit in such a way that, if at all, only small areas of the continuous train of the filter material remain unused. In addition, each can actually be desired Type of filter material used, which is continuous or intermittent can advance at any desired speed with minimal propulsive energy is required. Furthermore, #as filter system cleans itself of all gases, which are carried away by the liquid to be filtered.

While above preferred embodiments of the ore in manure have been described, it goes without saying that the invention is in no way limited to these exemplary embodiments is limited.

Rather, based on the exemplary embodiments, the person skilled in the art numerous possibilities for discoveries and / or additions to bids without this he would have to leave the basic idea of invention.

Claims (8)

p a t e n t a n s p r ü c h e 1. Automatic filter system for the From filtering impurities from a liquid bath, indicated by The following features: a) there are mounting devices (16, 17) for rotatable mounting a supply roll (15) with a web-shaped, continuous roll wound thereon Filter material (14) provided; b) there are guide devices (60 to 64) provided, with the help of which the web-shaped filter material (14) first down into the to purifying liquid bath is in and then led out of this upwards; c) a filter cell (40) is provided which is mounted in such a way that it is in the liquid bath can be lowered, and the at least one perforated wall (41) to support one side of a part piece voraeaebener length one after upward running strand of the web-shaped filter material (14) against a pressure difference in the liquid bath; d) the filter cell (40) has an inside Collection chamber (42) for receiving the through the filter material (14) and the perforated Wall (41) of filtrate passing therethrough; e) it is a liquid pump (13; 100) is provided, the suction side of which is used for sucking off the filtrate from the Sartnn-.elkammer (42) and for sucking the liquid through the filter material (14) and the perforated Wall (41) is connected through with the collection chamber (42) and during its operation the impurities contained in the liquid on the filter cell (40) facing away from the outside of the upward running strand of the web-shaped filter material (14) collected; f) there are interruption devices (83, 84; 107, 108) to interrupt the suction of the pump (13; 100) and thus to reduce the Pressure difference and to release the filter material (14) from the perforated wall (41) provided and g) incremental devices (18, 20, 21) are provided, which are arranged outside the liquid bath and with the filter cell (40) align and with the help of which the filter material (14) with the impurities can be detected and can be removed from the filter cell (40) in such a way that fresh areas of the Filter material (14) aeaenüber the perforated Taand (41) can be aligned. 2. Filter system according to claim 1, characterized in that the perforated area of the filter cell (40) has a smaller width than the web-shaped Has filter material (14), so that on both long edges of the filter material (14) Pand areas free of # 7 impurities remain that the indexing devices a driven roller (20) which is connected to the underside of the contaminants The filter material (14) interacts and the pressure rollers (21a, 21b) are provided, with the help of which the clean longitudinal edges on the top of the filter material can be detected and pressed against the driven roller (20). 3. Filter system nach.Anspruch 2, characterized in that the driven roller (20) has a knurled surface and extends over the entire width of the underside of the web-shaped filter material (14). 4. Filter system according to claim 2, characterized in that the with the top side of the filter material (14) cooperating with rollers (21a, 21b) idling, are resiliently biased against the driven roller. 5. Filter system according to claim 1, characterized in that the Guide devices have at least one pair of flanges which are perpendicular to the path of the web-shaped filter material (14) to the outside of the filter cell (40). stand out and so adjacent to the longitudinal edges of the filter material (14) are arranged so that these in the desired manner opposite the perforated Wall (41) of the filter cell (-40) can be aligned. 6. Filter system according to claim 1, characterized in that a primary tank (12) is provided, which is a first liquid bath to be filtered Contains liquid that a secondary tank is provided, which is a second liquid bath contains the liquid to be filtered, in which the filter cell (40) can be lowered, and that a SyDhonanordnunq is provided through which the liquid from the primary Tank like this in the secondary tank. it can be introduced that the liquid level in in the secondary tank does not rise above the liquid level in the primary tank. 7. Filter system according to claim 1, characterized in that above of the liquid bath #Talterungseinrichtuncren are provided that the filter cell (40) is suspended from the holding devices in such a way that they enter the liquid bath immersed that the hahnformiae filter material (14) on his way down on one side of the filter cell (40) and on its way up along the perforated wall (41) on the opposite side of the Filter cell (40), and that adjusting devices are provided with the help of which the Angle of inclination of the filter cell (40) in the liquid bath in relation to the holding devices is adjustable. 8. Filter system according to claim 7, characterized in that the The filter cell (40) is pivotably suspended on the holding devices in such a way that that it is pivotable about a horizontal pivot axis (90).