Washing apparatus for filter cloths.

p0001The invention relates to a washing apparatus in particular for fixed to filter plates of chamber filter presses filter cloths having the features specified in the preamble of claim 1.

p0002In chamber filter presses is at certain intervals the need, the filter cloths of residues, etc. to free dirt in order to achieve optimum filter characteristics. In order to minimize the labor and time required for automatic washing devices for chamber filter presses are known. For example, in US Patent No. 3,780,747, such a washing device for filter cloths of chamber filter presses is indicated. This essentially comprises a movable in the pressing direction transverse member and a movable on this crosspiece Travers cart. At the Travers car a vertical support arm is disposed raised and lowered, at its free end two horizontal, parallel spray bars are mounted as a spraying device. These spray bars engage in the space between two partial stack of plates. They have a variety of series-arranged nozzles from which - fed by a bulky high-pressure pipe - water or an appropriate cleaning liquid is injected under high pressure to the exposed filter surfaces of the filter cloths of two mutually facing press plates. During the washing process, the entire width of the filter surface is simultaneously detected by the washing jet of the spray beam is swept and the entire cleaned surface by means of adjustment of the supporting arm over the entire height of the filter cloth. If desired, several times in succession are carried out up and down movement of the spray beam. After the washing process, the spray boom is retracted together with the support arm by shifting the Travers carriage on the cross-beam side of the gap between the two filter plates, moved a plate of a partial stack of plates for the second and retracted the washing device in the now exposed gap under previous shift in stacking direction.

p0003The washing apparatus according to US Patent 4,076,033 comprises a horizontally disposed spray bars with a plurality of cleaning nozzles. The spray bar engages the plate interspace and is mounted movable in the vertical direction by means of a rack. it can cover the entire plate height by the driving movement, the plate width is covered by the length of the spray bar. In order to achieve a satisfactory cleaning result, the spray bar is displaceable in the horizontal direction over a distance which corresponds approximately to half the nozzle pitch. By shutting down the spray bar and the subsequent startup in the horizontal offset position there is a laterally offset, in strips cleaning of the filter cloth. Since generally the nozzle can not be arranged in an arbitrarily small distance from each other, no flat spray nozzles need to be used in the described spray device which have a poorer cleaning action.

p0004The washing apparatus according to the prior art described above have disadvantages in many respects. Due to the large number of mounted along the spray bar high-pressure nozzle is consumed during operation a lot of water. This requires at the high, required water pressure of about 100 bar a correspondingly high flow rate of the associated water pump. The driving this electric motors shall be construed accordingly, as a guideline apply performances from 30 kW in washing devices for small chamber filter presses (plate area 0.8 × 0.8 m) up to 75 kW in presses with a plate area of ​​1.5 × 1.5 m.

p0005By the necessary displaceability of the washing apparatus, the supply line for the cleaning fluid must be flexible. This normally requires the use of a high-pressure hose. Since this must promote bar a liquid amount of 140 liters per minute to more than 300 liters per minute at a pressure of 100, it has a correspondingly large diameter. This means that the high pressure hose during operation of the washing apparatus tough, is exceptionally inflexible and thus difficult to manipulate. It must be provided as a rule, special tours and open spaces in the press area of ​​the pressure hose. In addition, care must be taken that the operator when switching on the washing device is not damaged by the high pressure hose itself. This can namely around fast cash uncontrollably at its impingement by a water pressure of about 100 and meet operators or facilities, in the worst case. To prevent this, separate protective devices, guides or the like. necessary. In order to avoid this disadvantage from the outset, washing devices are known in the prior art, in which the high-pressure pump is arranged directly in the region of the supporting arm or spray bar, such that only a standing under atmospheric pressure water supply hose is needed. However, by this placement of the high-pressure pump, the construction cost for the washing device exalts himself considerably since these much higher loads must bear.

p0006A further disadvantage of known washing devices, with a plurality of high-pressure nozzles is the fact that a large amount of water is sprayed at the same time during the washing process. This results in a wide area around the chamber filter press a spray which wets all standing there operating facilities and also produces unfavorable climatic conditions at the operating site. Here it has been attempted to achieve an improvement by side and above the spray bars arranged splash walls. However, this in turn means an increased constructive effort for the washing device itself.

p0007Starting from the aforementioned disadvantages of known washing devices, the invention is based on the object to provide a washing device for fixed to filter plates of chamber filter presses filter cloths that a simple design requires a much lower flow rate of cleaning fluid and thereby avoids the mentioned to the prior art disadvantages.

p0008This object is solved by the characterizing features of claim 1. Accordingly, the injection device of the washing device is fitted as a spray head nurmehr a pair of nozzles, from which two nozzle exit respectively a high-pressure washing jet. These syringes are each in one of the two opposite, substantially parallel to the stacking direction pointing towards the opposite filter surfaces of the filter cloths main beam directions of the washing apparatus.

p0009Spray head and actuator arm are movably mounted to the plate stack to sweep the entire plate width in the transverse direction. By superimposing a movement in this direction with the already known to the art movement in the vertical direction of the filter plate can thus be virtually the entire filter surface of the filter cloths "scanned" and thus purified. For this purpose, the spray head is moved, for example, in the transverse direction over the entire width of the filter cloth, is on the edge slightly shifted in the vertical direction and then proceed back to the opposite edge of the filter cloth. The closer the vertical displacement of the injection head between the transverse speeds, the better the achievable cleaning results.

p0010The use of only two nozzles reduces water consumption tremendously. The delivery rates required are from about 15 to 50 liters per minute, which to one sixth of the flow rates corresponding to about one-tenth in known washing devices. With the same water pressure of 100 bar, this means that the high-pressure hose for supplying the cleaning liquid can be much thinner. The inner diameter of the high-pressure hoses to the prior art and the invention behave like about 5: 1, the required tube wall thicknesses for reasons of strength increase disproportionately with the inner diameter. Accordingly, the ratio of the outer diameter and the rigidity ratio of the compared hoses when exposed to a water pressure of 100 bar is still much higher. Quite clearly the high-pressure hose can be compared with washing devices according to the prior art with a fire hose, while the high-pressure hose more similar to a garden hose with the subject invention. It must accordingly no elaborate protection and guide devices in the washing apparatus according to the invention may be present, the space required is correspondingly less.

p0011By smaller tube diameters and flow rates also the high pressure system of the washing device is far less susceptible etc. against hose damage.

p0012With the lower required flow rates of washing liquid and the associated pumps and drive motors are to be interpreted for this small. Typically, a motor output of 5 to 6 kW for the pump drive is sufficient, so that here too, the construction cost will be greatly reduced.

p0013Moreover, even significantly reduced because of the smaller dimensions of all components of the design effort for the Verfahrwerk. This is evident by comparing the structure of the invention with the US-PS 3,780,747.

p0014In summary, the washing device according to the invention a plurality of advantages over the washing devices according to the prior art. These are. By the much lower required flow easier handling through reduced dimensioning of the components and higher reliability In contrast, the disadvantage of an increased time required for the washing operation is accepted. Through the necessary scanning the filter surface in height and width direction of the filter plates, the time required for a complete cycle is indeed about twice to three times as high as in washing apparatuses according to the prior art, since the cleaning of the filter cloths but only at intervals of one week to one month must be performed, this drawback is less relevant.

p0015The subclaims relate to advantageous developments of the subject matter.

p0016according to claim 2 the spray head and adjusting arm are mounted on a plate above the stack in the stacking direction movably mounted support bridge whose width substantially corresponds to the width of the filter plates. By shifting the carrier bridge in stacking direction successively each plate interspaces for cleaning all filter surfaces of the filter cloths can be achieved. The movement in the transverse direction by a correspondingly movable mounting of the actuating arm scored on the support bridge.

p0017By marking feature of claim 3 existing components of the chamber filter press for the storage of the washing device can be used. Typically, a carriage for the disk drive in the stacking direction is namely in chamber filter presses above the plate stack on both sides thereof are arranged in the stacking direction longitudinal struts movably. This draws in the plate emptying respectively the frontmost filter plate of the plate stack away from, so that the filter cake can fall out of the filter chamber. By Drehrichtungsumsteuerung the disk drive carriage moves back and forth and opens successively each filter chamber. On the longitudinal struts which support bridge can be mounted movable in stacking direction of the washing device in addition.

p0018The mobility of the actuating arm and the spray head of the washing device in the transverse direction to the plate package is achieved according to claim 4 by a carriage on which the actuator arm is mounted with its mounting end. The carriage is mounted on movable arranged transversely guide rails of the support bridge.

p0019according to claim 5 of the actuator arm of the spray head for raising and lowering the nozzle pair is formed telescopically. A configuration of the subject matter according to the claims 1 to 5 are provided for the scanning movement of the spray head with constructively simple means the three required degrees of freedom (longitudinal, lateral, vertical direction). In particular, the spray head in its movement during the washing process can be controlled so that it is the change of the plate interspace not laterally, but passed above the plate stack at this. Along with a supply of high-pressure hose from the top claims the washing device laterally from the plate stack no room. Consequently, several filter presses are close to each other can be opened, the lower space requirement for a complete multi-press system is obvious.

p0020according to claim 6 of the path of the spray head during the washing process in cross and vertical direction corresponding to the plate shape is controllable. Thus, the entire filter surface of the filter cloth are dimensionally accurate swept by washing beam. This further development of the subject invention is especially advantageous in connection with special types of filter plates. For technical reasons, filter plates are in fact known which are irregularly shaped, ie the lateral bulges, recesses, etc.. exhibit. In conventional washing devices over the entire plate width extending spray bars would not be cleaned in the presence of such irregularities either a part of the filter surface or wash liquid partially sprayed next to the filter plate. Another advantage of the controllability of the travel of the spray head in accordance with the plate shape is the fact that by one and the same washing device for plates under various shapes and, in particular width may be used. It must be adapted in the transverse direction of the plate width, only the maximum travel. For the control of the travel (end stop), electro-optical sensors (photocells) or intelligent control systems such as NC control the motors for lateral and vertical movement can be controlled by electromechanical sensors.

p0021Due to the smaller dimensions of all components of the washing apparatus according to the invention, it is possible to form them as an optional feature that is placed on the longitudinal struts of a chamber filter press (claim 7). After the washing process, the washing device can be re-collected and used in another filter press. This may even be the reasons given above have a different plate width or shape.

p0022A further achieved by the compactness and small sizing of the washing device according to the invention advantage is the ability to manufacture the entire washing apparatus made of corrosion resistant stainless steel. This is often essential if aggressive liquids and substances are treated in the filter presses. The expansive and oversized components in washing devices of the prior art may be manufactured from stainless steel would mean an unacceptable cost.

p0023Particularly advantageous combination of the washing apparatus according to the invention is seen with a chamber filter press according to DE-PS 34 08 140th The washing device is to be integrated into the disk drive slot, which is mounted movable on the longitudinal struts of the filter press. In the aforementioned patent, a special control for the disc drive carriage is provided that moves the individual filter plates of chamber filter press for emptying the filter cake. Short outlined done the displacement drive for the plates of the chamber filter press in order to avoid injury gentle and soulful, yet ensures a safe displacement of the plates from one to the other end position. Exactly these properties and advantages can be achieved during the washing process also in connection with the displacement drive.

p0024The invention will be explained in more detail in an embodiment with reference to the accompanying figures. Show it:<ul><li>Fig. 1 is a perspective, schematic view of the washing device and</li><li>FIG. 2 is a schematic side view of a chamber filter press with in-functional position washer.</li></ul>

p0025The washing apparatus 1 of the invention is used for cleaning the filter surfaces 2 of attached to the filter plates 3 of the chamber filter press 4 filter cloths 5. consists essentially of the carrier bridge 6, the carriage 7 and the attached actuating arm 8, is attached to the free end 9 of the spray head 10th

p0026The support bridge 6 includes longitudinal beams 11, which are mounted movable for instance with rollers on the above package of panels 12 on both sides thereof are arranged in the stacking direction 13 longitudinal struts 14 of the chamber filter press. 4 The movement drive takes place, for example, or the like by a screw, chain, timing belt. By traveling carrier bridge 6 of the freedom of motion of the washing apparatus 1 is placed in the stacking direction 13, whereby the washing apparatus 1 is 15 set respectively corresponding to the longitudinal axial position of the plate interspace.

p0027The two longitudinal beams 11 of the support bridge 6 are connected by the guide rails 16, on which the carriage 7 is arranged to be movable in the transverse direction. The carriage 7 is also mounted on roller bearings, its drive, for example, its own electric motor (not shown) are generated. Due to the movability of the carriage 7 to the guide rails 16 of the freedom of motion of the washing apparatus 1 in the transverse direction is given 17th

p0028On the carriage 7 is mounted with its attachment end 18 of the actuator arm 8 of the washing device. 1 The arranged on the free end 9 of the spray head 10 of the washing device 1 includes a pair of nozzles, from whose two nozzles 19, the cleaning liquid 20 is sprayed in the two main beam directions 21, 21 'under high pressure. The two main beam directions 21,21' each have opposite, parallel to the stacking direction 13 of the filter surfaces 2 of the filter cloths. 5

p0029The third degree of freedom of movement required of the washing device 1 in the height direction 22 is achieved by the telescopic division of the actuating arm eighth On the carriage 7 to be guide member 23 is mounted, in which the spray head bar 24 up and is stored abbeweglich. The up and down movement is possible, for example, by the engagement of a pinion in a arranged on the spray head bar 24 rack.

p0030The washing process is carried out as follows: Starting from an inactive position of the washing apparatus 1 over the stack of plates 12 raised spray head 10 the respective foremost, already cleaned on one side filter plate 3 subtracted from the (not shown) disk drive carriage from unpurified stack portion and to last shifted, cleaned on both sides of the filter plate 3" shifted (Fig. 2). This creates a new disk space 15 is opened vertically and parallel to the face to both sides to be cleaned filter surfaces 2 of the filter cloths 5 itself. Subsequently, approximately centrally inserted into the disc space 15 of the spray head 10 by corresponding displacement of the support bridge 6, the carriage 7 and the spray head rod 24 of the actuating arm. 8 By a corresponding control in the transverse direction 17 and height 22 of the spray head 10 along the travel 25 shown in FIG. 1 is moved, whereby the entire filter to be cleaned surface is successively "scanned" and purified by Hochdruckabspritzung. The traverse 25 shown is merely exemplary. For rational reasons this is, however, to choose as short as possible. Any "meandering" to sweep the entire plate surface are conceivable, however, makes little sense. As is apparent from Fig. 1, even an irregular plate shape with the lateral protrusions 26 and recesses 27 can be cleaned by appropriate selection of the traverse 25, without loss of cleaning liquid through the washing device according to the invention.

p0031As is apparent in Fig. 2, the nozzles 19 are fed via a high-pressure line in the actuator arm 8 from the high-pressure hose 28 which is connected at the rear end of the actuating arm 8. The high pressure hose 28 is charged with the washing liquid with a pressure of about 100 bar by a (not shown) high-pressure pump, it has to cope with a flow rate of about 15 to 20 liters per minute. As indicated in Fig. 2, the high-pressure hose 28 may be somewhat above the chamber filter press 4 suspended displaced in stacking device 13. Due to its small diameter - about a garden hose comparable - it is flexible enough despite admission by the high water pressure for such a suspension.

LIST OF REFERENCE NUMBERS

p0032<ul><li>1 washer</li><li>2 filter area</li><li>3 filter plate</li><li>4 chamber filter press</li><li>5 filter cloth</li><li>6 support bridge</li><li>7 carriage</li><li>8 actuating arm</li><li>9 free end</li><li>10 spray head</li><li>11 Main beam</li><li>12 plate stack</li><li>13 stacking direction</li><li>14 longitudinal strut</li><li>15 plate interspace</li><li>16 guide rail</li><li>17 transversely</li><li>18 fastening end</li><li>19 die</li><li>20 cleaning fluid</li><li>21,21' boresight</li><li>22 height direction</li><li>23 guide member</li><li>24 spray head bar</li><li>25 traverse</li><li>26 bulge</li><li>27 recess</li><li>28 High-pressure hose</li></ul>