DK174626B1 - Filling materials and process for making the same - Google Patents

Abstract

A filler and a process for producing it, where the filler, in the case of the biological treatment of sewage, should in particular exhibit a "biological meadow" which is necessary for this purpose, and a uniform moistening ability. In the case of known fillers which consist of strips, it has been found that the strips straighten under influence of encrustation and thereby form a pore foothold for the "biological meadow" and seek to become attached to each other. The purpose of the novel filler is to eliminate this drawback, and for it to be easy to manufacture and install. The novel filler exhibits at least one tensile member (fibre 29), which has been located beside the strips 20. When suspended, this takes up the load such that the strips 20 are essentially unloaded and thereby retain the shape they were given during manufacture. The filler is especially suitable for the biological treatment of sewage and drinking water, i.e. denitrification. <IMAGE>

Description

DK 174626 B1 i

The invention relates to a filler material made of plastic material for the treatment of liquids and of the kind specified in the preamble of claim 1. The invention further relates to a process of the kind specified in the preamble of claim 10 for the production of filler materials for biological wastewater treatment.

5 The fillers mentioned above serve primarily for biological treatment in wastewater engineering. In this application, the filling material serves as a carrier for the bacteria required for the biological treatment, namely a so-called biological mat. The use of a water treatment plant equipped with such filler material depends on several factors.

On the one hand, the filler material must have as large a specific surface area as possible, while on the other hand, the best possible bacteria retention is required on the filler material. Finally, the biological mat on the filler material must be able to flow freely or be moistened by the liquids to be treated.

From DK 5889/87 a filler material for use in biological wastewater treatment is known, and which consists of a number of plastic strips which are connected to each other by means of a holding web directed at 15 across the longitudinal strips. Also known from the same document is a method of making the filler material, in which a material web is pulled by a roll of material, moved past a plurality of knives and thereby continuously cut to form adjacent strips, after which the holding web is welded to the strips.

The known fillers of the kind mentioned above, that is, which comprise a number of strips of plastic material, have the disadvantage that the smooth strips tend to adhere to each other, whereby the liquid to be treated is no longer able to flows through the adjacent strips of the biological mat. The efficiency of a wastewater treatment plant equipped with these strips is thereby significantly reduced.

25 To prevent this, attempts have been made to use strips with a uniform, predominantly wrinkled surface. However, it has been found that due to the weight load on the strips from DK 174626 B1 2 the bilogical mat, which grows on it, strips that were initially wrinkled, with time straightened out, which means that these also gradually stick together .

Furthermore, it has been found to be costly to form drip bodies from the known strip-shaped fillers, since it is difficult to suspend the strips 5 from a suitable carrier with the required uniform distribution over the entire drip body.

The object of the present invention is therefore to provide an efficient and easily assembled strip-shaped filling material, as well as a process for the simple manufacture of the same.

The filling material according to the invention is characterized by the features specified in the characterizing part of claim 1. By placing at least one pull-up member on each strip, it is achieved that the strip does not straighten under the strain of the biological mat growing on the strip, which allows adjacent strips to adhere easily to one another. On the contrary, however, it has surprisingly been found that the strips provided with at least one pull-up member twist under load. Adhering to adjacent strips is thus practically no longer possible.

The pull-up member is preferably formed as a longitudinal pull-up (round) string extending longitudinally of the strip. It is easy to manufacture and has virtually no influence on the growth of the strip.

It has been found to be particularly advantageous to attach a single (middle) string to each strip. The thus-reinforced strips twist under load around the string, thereby forming approximately a longitudinal center axis of a coil.

Furthermore, according to the invention, each of the strands can be connected to the associated strips in such a way that when the strands are stretched out (rectilinear) the strips connected to these strips have at least in the regions of their opposite edges a shrinkage or wave-shaped progress. In addition, by means of the tensile picking strings, even when the strips are loaded, this form of the strips is maintained, the strands prevent an extension and thus the strips are smoothed out.

Further, a plurality of strips may be connected to each other by means of a holding web. The strips are preferably formed directly on the holding web, so that the strips and holding web are produced in one. This means that the strips are permanently connected to each other with sufficient strength.

On the opposite sides of each holding web, holding web groups of spaced apart strips are arranged across the lengths of the strips. Thus, from the parallel edges of the holding web, the strips extend in opposite directions in a hair-like manner.

Furthermore, in one embodiment of the filling material, the areas adjacent to the holding web between adjacent strips may be provided with clearance, which is provided when the adjacent strips have a small width throughout the extent of the clearance. The spaces of the filler material have the function that when the filler material is normally laid with the holding web and they descend along stretching strips across a support beam to conduct the dirty water supplied from above the support beam or web at all sides of the strips for uniform wetting thereof. .

Finally, according to the invention, the filler material can be formed in such a way that several holding webs with strips placed thereon are joined lying on top of one another in such a way that the holding webs - and only the holding webs - are connected to each other. The strips of each layer which are superimposed are thus not connected to each other and can thus be wet from all sides. With such a filler body, a relatively large number of strips are joined to form a one-piece unit which can be suspended in a carrier rack as a whole. This makes it possible to obtain high mounting services.

DK 174626 B1 4

The process according to the invention is characterized by the features of claim 10. Hereby, the strands serving to stabilize the strips are first prepared separately and then connected to the strips or a web of material which is subsequently divided to form a number of adjacent strips. The characteristic of this process is that the strands are connected in an even hot state with the cold strips or the cold material web. In this way, it is firstly achieved that the still hot strands are adhered or welded together with the strips or web without the use of adhesives or similar finishing agents. Secondly, by cooling the plastic strands and the associated contraction thereof, the cold strips or the web of material, which thus cannot contract further, are obtained. This wrinkle, which is desired because it serves to increase the specific growing area, is thereby provided by the method of the invention without the use of additional agents. Furthermore, according to the invention, several strands can be simultaneously sealed together with a web which is subsequently divided to form a larger number of adjacent strips. Following cooling of the strands, adjacent strips are provided by consecutive separation sections between two adjacent strands of the web. This method enables a high production capacity, since several adjacent strips can be produced simultaneously.

Furthermore, the holding web which serves to hold adjacent 20 strips can be provided by omitting the separating sections to form adjacent strips from the regular distance web. The holding strips are thereby provided in the simplest way by leaving the web used to form the strips unchanged in the regions of the holding strips. This results in a substantial simplification of the preparation of the filling material according to the invention.

Finally, according to the invention, a larger, individually manageable unit comprising a relatively large number of independent strips can be provided by joining a plurality of webs. To achieve this, a number of webs are joined after the individual strips have been cut and joined by their holding strips, preferably by welding. In this way, it is possible to join together a substantial number of strips and assemble them as a whole on a support rack or the like for the drip body.

Various embodiments of the filler material and apparatus for making the same according to the invention are explained below with reference to the drawing, in which: FIG. 1 shows a portion of a drip body with filler material suspended on a support frame; FIG. 2 from above the FIG. 1, FIG. 3 is a larger scale view from above of a single strip of the filler material; FIG. 4 is a cross-section through the embodiment of FIG. 3; FIG. 5 is a side view of the embodiment of FIG. 3; FIG. 6 is a top view of another embodiment of the filler material. FIG. 7 on a larger scale from above a portion of a strip of the one shown in FIG. 6, FIG. 8 is a side view of the one shown in FIG. 7; FIG. 9 shows a device for placing strings on a material web serving to form a plurality of strips; FIG. 10 shows a device for cutting the strips from the material web and for bringing together several superimposed webs; and FIG. 11 shows an alternative embodiment of the embodiment shown in FIG. 10 illustrates strip preparation apparatus shown in FIG. 6-8.

6 DK 174626 B1

The filler shown in the particular embodiments serves as a drainage body for biological wastewater treatment.

The 1-8 embodiments of the filler material comprise a plurality of adjacent elongated strips 20 connected to each other by a central, transverse holding web 21. The single strips 20 of the filler material are disposed here in three adjacent layers 22 and 23. As shown in FIG. 2, the two outer layers 22 comprise the same number of strips 20. The strips present in the outer layer 22 are arranged in substantially the same way. In comparison, the middle layer 23 has a strip 20 smaller. Thereby, the strips 20 in the middle layer 23 can be positioned offset relative to the 10 strips in the two outer layers 22 in such a way that the strips in the middle layer 23 are located in the middle between two strips 20 in the outer layers 22, thus in spacing. The length of the strips 20 is about the same in all layers 22 and 23.

As shown in FIG. 2, the strips 20 are located at opposite end regions 24 and 25 of the holding web integral with the holding web. Furthermore, the holding web 21 and the strips 20 adjacent to this strip 20 are formed from a common material web 26 which in the areas adjacent to the holding web 21 is provided with through-cuts 27 to form the strips 27. Thus, the adjacent strips 20 in each case separated from each other by means of a notch 27 extending through the free ends 28 of the strips 20 to the respective end regions 24 or 25 of the holding web 21.

In the embodiment shown in FIG. 1-5, each strip 20 has a pulling member, namely a string 29. As can be seen in particular in FIG. 2, in each case a straight strand extends from the free end 28 of a strip 20 disposed on one side of the holding web 11 and to the (opposite) free end 28 of a strip remaining on the other side of the holding web 21 25. Thus, each strand 29 connects two adjacent strips 20, the string 29 extending continuously across the holding web 21. The strands 29 are arranged in such a way that they are disposed on one side in the center of the strips.

DK 174626 B1 7

This can be clearly seen in the tig. 4. As shown in FIG. 2, each of the layers 22 and 23 has as many parallel strands 29 as they have adjacent strips 20.

As can further be seen in FIG. 2, but can also be seen in FIG. 1, the (end) regions of the strips 20 directed toward the holding web 21 are provided with notches 30. These notches 30 are generally rectangular and each lie between two adjacent strips 20, the strips 20 having a reduced width in the regions of the notches. 30 without, however, interrupting the strings 29. The purpose of the notches 30 is to ensure that when the drip body is in the state in which it is suspended on the support beam 31 of a support frame 32, the liquid which springs down on the drip body can reach the middle layer 10 23 strips and to the outer layer 22 directed to the beam 31, so that uniform wetting of all the strips 22 and 23 of the layers 20 can be achieved.

As can also be seen in FIG. 1, the different layers 22 and 23 in their middle region of their holding webs 21 are connected to each other by means of one longitudinal direction of the holding web 21 and welding seam 33 extending across the strips.

15 As shown in FIG. 3-5, the strips 20 relative to the string 29 which extend approximately have been shrunk in such a way that they have folds extending transversely in the longitudinal direction 34. The parallel edges 35 of the strips 20 thereby have a wavy course, which is shown particularly clearly. in FIG. 5. This course gradually decreases from the edges 35 to the (middle) string 29. In this embodiment, the strips 20 have a three-dimensional structure which provides an optimal surface for the "biological mat" to grow thereon and is intended for biological wastewater treatment. . In the embodiment shown, the string 29 has a substantially circular cross-section, the diameter of which is considerably greater than the thickness of the strip material. Suitable materials for the string 29 are thermoplastic plastics with little elongation, e.g. polypropylene or polyethylene. Thereby, the strips - supported by the string 29 - retain their lengths in a loaded state, that is, with one "biological mat" growing on the surface of the strips 20 to substantially prevent the strips 20 from aligning, especially at their wavy edges 35.

8 DK 174626 B1 Compared to the one shown in FIG. 1-5 comprises the material described in FIG. 5-7, strips 36, shown from above, extend snake-shaped, namely sinusoidal. These strips, as shown in FIG. 5-7, on the one hand, be provided with a string 37 extending here in a straight line. In the present embodiment, the strip 36 further extends alternately to one and the other side of the (straight) string 37, thus ensuring constant contact between the strips 36 and the string 37. Alternatively, the string may also be follows the snake-like course of the strips, whereby the string also has a snake-like course.

As shown in FIG. 8, the strips 36 parallel to hose-shaped extending edges 38 at 10 in the embodiment shown are shrunk such that these also have a wave-shaped course. Such strip 36 has a large spatial distribution which provides particularly large growth areas for the "biological mat".

In FIG. 9, there is shown a device for use in the manufacture of the strands 29 and for connecting them to a material web 26 which serves to form the strips 20. By means of the illustrated device, several spaced apart strands 29 are produced. by means of an extruder 39. The strands 29 coming out of the nozzle 40 of the extruder 39 remain in an even hot state, ie. a location immediately after the nozzle 40 joined with the cold web 26 and welded or sealed therewith. To this end, the material web 26 is pulled from a supply coil 41 and passed between roll pairs arranged therein, namely, in the present embodiment 3 roll pairs 42 between which also the still hot strands 29 coming from the nozzle 40 of the extruder 39 also pass. Passing the strands 29 and the material web 26 through the roller pairs 42 provides a welding of the strands 29 with the material web.

25 After the roller pairs 42, the material web 26 provided with the strings 29 is passed through a cooling station 43. This cooling station 43 has a plurality of support rollers 44 which abut the underside of the material web 26 and in the cooling device 45, DK 174626 B1 9 is arranged adjacent to the opposite upper side. of the material web 26 on which the strings 29 are located. If cooled in the cooling station 43, the strands 29 contract. Thereby the cold and thus not shrinking web of material 26 is contracted, thereby wrinkling especially at the edges 35.

5 After the cooling station 43, the wrinkled material web 26 provided with the strings 29 is wound up on an intermediate storage coil 46. The material web 26 thus processed can thereby be further processed by means of the ridge 29 shown in FIG. 10 to form the finished filler material.

In the embodiment shown in FIG. 10, the material web 26 provided with the strings 29 is then further worked into three planes. Hereby three material webs 26 provided with strings 29 are pulled simultaneously from three interposed storage coils 46. As each material web 26 is moved past a knife unit 47, the strips 20 are cut to form the (rectilinear) cuts 27 between adjacent strips 20. The knife head. there 47 may from time to time be raised by means of a lifting device not shown, so that they can be removed from engagement with the material web 26, thereby forming (not cut) holding webs 20.

Located downstream of the knife unit 47 to each material web 26, the device has punching devices 48. These punch the cut-offs 30 between adjacent strips 20. In order to obtain a continuous manufacture, the punching stations 48 may be designed "flying".

After the punching stations 48, a combination of all three material webs 26 provided with cut-outs 27 and 30 follows, the two outer layers 22 being guided via the guide rollers 49 towards the middle inner layer 23 and all the layers being joined between a roller pair 50. Following the roller pair 50, as seen in FIG. the direction of manufacture (arrow 51) a welding device 52. It serves 25 to join the layers 22 and 23 in the region of their holding webs 21 by forming the welding seam 33. The welding device 52 is periodically activated, i.e. once, the three holding webs 21 of the sheet 10 10 and 17 of the sheet 10 are in the region of the welding device 52.

Following the welding device 52, as seen in the manufacturing direction, a last pair of rolls 53 and a guide roller from which the filler material with the successive units are wound 5 are wound onto a supply coil 55. From here, filler material units can be individually removed one after the other for the application of drainage bodies to supporting supports 32. 31st

At least one of the roller pairs 50 and 52 of the device can be rotated to pull the material web 26 to be finished through the knife unit, the punch unit and the welding device.

Alternatively, it is also possible to place it in the body. 10, immediately downstream of the device shown in FIG. 9 shows the first device section. In this way, the winding of the web provided with the string 29 is omitted on the intermediate storage spool 46. An alternative which is particularly suitable for the preparation of the filler material of a single-layer material web 26. But also a multi-layer filler material can be prepared in successive steps, namely when the individual layers 22 and 23 can be manufactured simultaneously by several extruders 39. Finally, in FIG. 11 shows an alternative of the one shown in FIG. 10.

This is particularly suitable for making tubular strips 36 shown in FIG. 6-8.

The waves of the tubular strips 36 are formed here by means of a thermo-cutter pin, 20 cutting knife, cutting roller or similar cutter 56, which, during the continuous forward movement of the material web 26 in the manufacturing direction 51, regularly travels back and forth across it. This orthogonal directional overlay serves to simply form parallel, wavy edges 38 on the strips 36.

Claims (13)

Filler material made of plastic material and for the treatment of liquids, especially for biological wastewater treatment, having a plurality of strips of plastic material, characterized in that the strips (20, 36) have at least one pull-up member (strands 29, 37). . Filler material according to claim 1, characterized in that the pull-up member (s) is designed as a pull-up string (29, 37) extending in the longitudinal direction of the strips (20, 36). Filling material according to claim 1 or 2, characterized in that on one side of each of the strips (20) provided with equally parallel edges (35), a single strand (29) is arranged approximately in the middle. Filling material according to claim 1 or 2, characterized in that on the one side of each of the 15 strips (36) provided with uniform, wavy, parallel-extending edges (38), an approximately equal string (37) is arranged on a such that the string extends the straight line throughout the length of the strips (36) between their wavy edges (38). Filler material according to claim 3 or 4, characterized in that the tensile receiving string (29, 37) is fixedly connected to the strips (20, 36) preferably by welding or sealing and also in such a way that when the string (29, 37) ), the rectilinear 20 extends to those strips (20, 36) associated with it. Filling material according to one or more of claims 1 to 5, characterized in that the strands (29, 37) have a roughly circular cross-section, that the diameter of the strands (29, 37) is a number of times greater than the thickness of the strips (20, 36). ) and that the strands (29, 37) preferably consist of a low elongation thermoplastic plastic material, e.g. polypropylene or polyethylene. Filling material according to one or more of claims 1-6, characterized in that the strips (20, 36) are preferably connected to a holding web (21) in one piece. Filling material according to claim 7, characterized in that groups of spaced strips (20, 36) are arranged on the opposite sides of the transversely directed holding web (21) and that the strips (20) is formed by means of cuts (30) in an area adjacent to the holding web (21). Filling material according to claim 7 or 8, characterized in that several holding webs (21) 10 with strips (20, 36) placed thereon are joined together lying on top of one another and joined together on the holding webs (21). Process for producing a biological waste water filler material of a plurality of strips of plastic material according to one or more of claims 1-9, characterized in that one or more continuously produced (extruded) strands (29, 37). ) in a still hot state is continuously applied to the strips (20, 36) or a web of material (26) which is subsequently divided to form a number of adjacent strips (20, 36). Method according to claim 10, characterized in that a plurality of still hot parallel strands (29, 37) under pressure are sealed together with or welded 20 together with the material web (26) which is subsequently divided to form a number adjacent to each other. strips (20, 36). Method according to claim 11, characterized in that after the strands (29, 37. have been sealed or welded together with the material web (26), the web (26) with the strands (29, 37) is passed through cooling means (45), wherein The material web (26) shrinks because the strands (29, 37) contract during cooling, and the material web (26) is split to form a number of adjacent strips (20, 36). Method according to claim 11 or 12, characterized in that, after the strands (29, 37) have cooled, the material web 5 (26) is continuously divided between pairs of adjacent strands (29, 37) to form adjacent ones. strips (20, 36) with strands (29, 37) attached thereto in such a way that the cutting of strips (20, 36) in the material web (26) is periodically omitted to form holding webs (21) connecting them at side-by-side strips (20, 36). 10