CA1282193C - Film-flow packing for biological treatment of fluids - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A plastic packing is disclosed for biological treatment of fluids, comprising a series of plates packed without the use of adhesive, and provided with convex and concave ribs wherein inclined channels with corrugated side-walls are arranged between the adjacent sheets. The sheets are formed by M-profiles, the connecting lines and centrelines of the M-profiles being unbroken to the full height of the packing and at maximum angle of 30° to the vertical.
Furthermore, the corrugated parts are ribbed surfaces formed only on the shanks of the M-profiles, so that a flat strip without ribs exists on both sides of the connecting lines of the profiles.

Description

The invention relates to film-flow packiny treat-men-t of fluids, comprising the use of a sèries of plates provided with concave and convex ribs, wherein inclined channels with corrugated sides are formed at an angle between the adjacent plates which are pac]ced -together.
As is known -the quality of wa-ter ~epends on i-ts physical, chemical and biological properties. In -the preser-vation of the quality of water, adequate purification of sewage waters has become a central problem of environmental protection in recent years.
The various technologies of water and sewage purifi-cation include physical, chemical and biological processes.
In one version of biological process, so-called drip bodies are used as the primary purification phase of mainly multi-phase sewage wa-ter purification technologies. Their applica-tion enables carrying out of active slimy biological purifica-tion technology at higher efficiency.
The packing structure of the biological drip bodies contains various materials, in the wake of the development that nearly exclusively plastic packings are used -today.
The packings are arranged on top oE each other, buil-t up as a tower to form the drip bodies with a water distributor on top of the tower.

According to the principle of operation of biological drip bodies, the waste or sewage water flows down intermit-tently or continuously over a biological film developed on the surface of the packings. This brings about coagulation `

~ 3 and absorption of poll.utants, in the course of which micro-organic cultures orming the biological film dissolve the solute o:E water to be utilized for gaining ener~y and cell synthesis. The overmul-tiplied biological ~ilm ~rac-tions agglomerate in a sedimentator, and through the cell-free enzyme activity of the microorganisms are decomposed to material which diffuses through -the cell wall and thus parti-cipates i.n the me-tabolism process.

The oxygen required for biochemical oxidation is supplied by air passing through the packing. Flowing down in the drip body the BOI5 value oE the waste waters diminishes exponentially.
Thus the packings used in the biological drip bodies must meet several requirements:
Surface related to unit volume of -the packings covered by the biological film has to be as large as possible.
At the same time the volume of voids also has to be large in ~he packing to have a sufficient free cross-section for the filmy downflow of the waste wa-ter and an adequate oxygen supply should be available.

Apart from this, the packings must be resistant against chemical, biological and physical effects and they must possess adequate static strength in order that the biological Eilm should be able to carry the weight of water ~5 and several packing units arranged upon each other.
Further obvious requirements are easy, simple and fast production of the packings, as well as their fast and simple installation, operation and main-tenance.

~282~93 In -the spiri-t of the above eEfor-ts several known solutions were developed. One of the best known versions is described in the British Patents l,065,612 and l,080,991.
The elements are plas-tic sheets with straigh-t or curved generatri~ ~nd accordion-like corrugated surfaces. These are generally arranged alternately with Ela-t shee-ts so tha-t -the elemen-ts are -turned opposite -to each other.
The fundamen-tal shortcoming of this prior construction is that, as a result of using flat sheets to increase mechanical strength, the specific surface is a relatively small 85 m2/m3 which results in poor eficiency.
Such solution is also used, where the packing consists of sheets corrugated in strips, and the sheets are provided with reticular reinforcing elements on the top and bottom. In this case, there is no closed channel system and, although its specific surEace is larger than that of the earlier mentioned solutions, the mechanical loadability of the packing is low.
A German Federal Republic~ Patent 1,299,665 a packing is described, which consists similarly of sheets folded as an accordion. Corrugations of the adjacen-t sheets intersect each other and the sheets are made of moisture absorbing material. The specific surface of -the elements is relatively small, the mechanical strength is low, and they are unsuitable for use in biological drip bodies.
A solution is also known (see German Democratic Republic Patent 58jlO4) which consists of trapezoidal `` ` ~f32~L~3 corrugated sheets. Flat sheets are arranged between corru-gated sheets with oblong slo-ts on the corrugated sheets.
The specific surface is small, mechanical s-trength is poor, and the field of applica-tion is mainly contact aE liquid and gas.
The plastic packing described in ~lungarian Pa-tent 172,169 represents definite progress compared to the earlier mentioned solutions. This is provided with corruga-ted through channels separated from each other, where the channels are of regular hexagonal cross-section in any horizon-tal section of at least one part of the packing. The longitudinal axes of the channels in the vertical plane consist of opposite sections following each other at least in part, and preferably two adjacent sides of each channel are provided with corruga-tions in transverse direction to the longitudinal axis.
This construction enables the specific surfaceto be increased to 135 m2/m3 and yields very good results.
However it has two fundamental drawbacks: the sheets forming the packing are assembled with the use of adhesive. This is expensive, for it requires filler material and fur-ther aids and the gluing technology entails the risk of accident, since the appied solvents are poisonous and represen-t a gas and explosion hazard.
A further drawkack is that the longitudinal axes of the channels are a-t a relatively wide angle to the vertical (30-50). Thus, as a result of gravity, water flows on the lower part of the channels during operation. This means that, mainly due to heavy surface load, the surface participating in intensive purification may be reduced to 50%
of the total surface. Hence operation of these packing units is flexible against change of load only over a relatively narrow range.
Clogging, inundation or other failure of the packing requiring repair or maintenance frequently occur even duriny the most careful operation of the bioloyical drip bodies.
Jointing the sheets with adhesive is unfavourable in this respect too, for the sheets cannot be separately replaced, and cleaning and maintenance are difficulto An object of the present invention is the elimination of the deficiencies described above and the provision of a plastic packing capable of exposure to heavy load particularly for biological drip bodies, the production assembly, repair and maintenance of which are inexpensive, fast and simple, and as a result of large specific surface the operation of which will be more efficient and economical.
Accordingly, the invention provides a packing for the biological treatment of a fluid, comprising a plurality of sheets of a synthetic resin material and horizontally abutting adjacent sheets, each of said sheets consisting of:
a plurality of substantially coplanar and identical M-section corrugations each having a pair of angularly adjoining relatively short shanks along a crest of each of said corrugations and a respective relatively long shank angularly adjoining each relatively short shank, said relatively short shanks having lengths in cross-section of substantially 1 to 200 mm said respectively long shanks having lengths in cross-30 section of substantially 10 to 200 mm; and wherein each of said relatively long shanks angularly adjoining a relatively long shank of an adjacent M-section corrugation along a V-section trough of the sheet; said crests and troughs being inclined to the vertical and the inclination to the vertical being a maximum of 30; each of said long shanks being provided with ribs transverse to the longitudinal dimension ~, ) ~3 of the respective crest and extending from the respective crest toward but terminating short of the end of the respective relatively long shank at its trough so that along a joining line of each relatively long shank with an adjoining relatively long shank a respecti~e rib-free flat surface is formed on each relatively long shank, said flat surfaces having widths of substantially 1 to 200 mm; and said crests and troughs of said corrugations extending substantially the full heights of the respective sheets, said ribs having heights of substantially 2 to 16 mm.
Thus, the sheets of the generally plastic packing according to the present invention are formed with M-profiles provided with regularly repetitive convex and concave sheets advantageously connected to each other ~ithout the use of adhesive. Channels with corrugated side-wall are arranged at an angle, and the connecting lines and centrelines of the M-profiles are unbroken to the full height of the packing and are at a maximum of 30 to the vertical. Furthermore, the corrugated parts have ribbed surfaces formed only on the shanks of the M-profiles so tha~ flat strips without ribs exist on both sides of the connecting line of the profiles.
In the packing according to the invention the sheets are generally connected withoùt adhesive. The M-profiles may be flat or curved surfaces.
The connecting lines and centrelines of M-profiles are about 5 to the vertical in a preferred construction.
The ribbed surface is formed preferably by M-profiles or alternately M and V-profiles, where the connecting lines and centrelines of the profiles consisting of flat sheets are horizontal.
In a given case, the profiles may be rounded at the tips and joints of the shanks. The tips and shanks are preferably at an angle of approximately 90.
The length of the upper branches of the M-profiles forming the sheets is generally from 1 to 200 mm, preferably ab~u~ ~ mm. Th~ wld~h Of ~h~ flat gt~lps at th~lr e~es 1~

c~r-) ,'i. 3 similarly from 1 to 200 mm, preferably about 3 mm, while the length of the profile shanks is from 10 to 200 mm, pre-ferably about 25 mm.
The height of the M and/or V-profiles forming the ribbed surface is generally from 2 to 16 mm, preferably about 5 mm. The angle between the profile shanks is preferably about 60.
The length and width of the sheets forming the packing are preferably from 500 to 3000 mm, while the size of the sheets in a practical embodiment if 500 x 1000 mm.
According to one embodiment of the invention, the sheets forming the packing are joined opposite each other so that shanks of the M-profiles end at a junction point.
According to another embodiment, the sheets are turned in the same direction, spaced and connected to each other at a distance of 1/2 M-profile so that the shanks of ~-profiles on one sheet fit into the troughs on the upper parts of M-profiles on the adjacent sheet.
The plastic sheets forming the packing may be made ofpolyethylene,polystyrene,polypropylene,polyvinylchloride or hard polyethylene foil with vacuum mouldiny.
The fundamental advantage of the plastic packing according to the invention is that its specific surface can be increased even to 500 m~/m3, which is a multiple of the earlier best solution. Its operation is flexible even under high hydraulic, or surface load, and thus the amount of charge built in for the given capacity can be reduced by 30 - 40%.
Two types of packing can be constructed from the uniformly shaped plastic sheets according to whether the sheets are connected by turning them in the same direction or opposite to each other. The connection is shape-retentive, thus gluing is unnecessary. At the same time, in the case of cleaning or failure it is easily assembled and ~isassembled, and each sheet can be separately replaced.
The volume of voids is large and the angular deflection of the channels is small in relation to the ~2~

vertical, which ensures ample and efficient air supply. Owing to the special formation of the tips, the static strength is very good and the structure functions even under mechanical load.
The plastie sheets forming the paeking according to the invention can be produced simply, quiekly and in various sizes, the production teehnoloyy being adapted to conventional technology.
Embodiments of the invention will now be deseribed, by way of example, with reference to the accompanying drawings, in which:
Figure 1 shows a side view of plastic sheets forming an embodiment of the packing according to the invention;
Figure 2 is a cross-section along line A-A of Figure 1 of the structure shown in Figure 1;

'~

~2~32~33 g Figure 3 is a cross-section along line B-B o Figure 2 of the structure shown in Figure 2;
Figure 4 is a cross-section of ribs in another embodiment;
Figure 5 is a cross-sec-tion of ribs in a further embodiment;
Figure 6 shows a top view of an alternative packing assembly with shee-ts; and Figure 7 is a top view of a still further embodiment of the packing.
As shown in Figures 1 and 2, sheet 1 is assembled with M-profiles 2, so that shanks 3 mee-t each other along jointing line 5. The jointing lines 5 of M-profiles 2 and centrelines 7 at the junction of upper branches 6 are at an angle a to the vertical. In this case a=5. The length - of the shanks 3 of M-profiles is 25 mm, the length of the upper branches 6 is 5 mm and the angle ~ between the shanks 3 is 90.
The shanks 3 of M-profiles 2 are each provided with a ribbed surface 8. The ribbed surface 8 does not extend over the full length of shanks 3, but flat strips 9 withou-t ribs exist in the vicinity of the jointing line 5. Their minimum width is about 5 mm.
Figure 3 shows a section B-B of the ribbed surface 8. The ribbed surface is formed by alternately jointed M-profiles 10 and V-profiles 11, so that the M-profiles 10 and V-profiles 11 are disposed alternately opposite each 3.~

other. The height of the M-profiles is 3 mm, and the angle between the shanks is 60.
Naturally the ribbed surface 8 can be formea differ-ently. Figure 4 shows an embodiment with V-profiles disposed alterna-tely opposite each o-ther. Figure 5 shows a sectional view of the ribbed surface 8 in a further possible embodiment, where the profile of -the ribs is trapezoidal. The sheets 1 can optionally be made of synthetic foil, e.g. polyethylene, polystyrene, polypropylene, polyvinylchloride, hard poly-ethylene, etc.
The packing according to the invention can be produced with sheets 1 in several versions. In the embodiment shown in Figure 6, sheets 1 are turned in the same direction, and jointed to each other spaced at half distance of -the M-profile. In this way, the angle between shanks 3 is the same as the angle between upper branches 6, and thus shanks 3 or sheets 1 fit into troughs 4 formed by the upper branches 6 of the adjacent sheets 1.
Channels 12 of square ~or in a given case rhomboidal) cross-section are provided in the packing of closed section.
Only trough 4 formed by upper branches 6 of M-profiles 2 is missing from the full square or rhomboidal cross-section.
The surface per unit volume of the packing of closed section shown in Figure 6 is very large, and may even reach 500 m2 /m3 The structure shown in Figure 7 also has a relatively large specific surface, although its value is lower than ~ns~

that of the structure shown in Figure 6. Here, -the sheets l are jointed opposite each o-ther, so tha-t the sheets of M-proEiles end in a junction point in the horizon-tal section.
Since, in this case, the jointing lines 5 and centre-lines 7 on the shee-ts 1 are opposite each other, no closed sec-tion exists in this embodimen-t.
The specific surface of packinys assemb~ed with sheets as shown in Figure 6 or 7 is several times larger than that of~the convèntional solution, and the rela-tively narrow angle to the vertical of the sections and channels results partly in high stabili-ty and partly in optimal operation. The waste water is intensively purified on bo-th sides of the sheets under varying or impulsive surface load, and consequently the structure is flexible against change of the surface load.
Flow velocity of wa-ter on the sheets is controlled by ribbed surface 8. This surface facilitates adhesion of the biological film and increases -the specific surface.
Thus the packing according to -the invention increases the efficiency oE the biological drip bodies, while the amoun-t of charge is reduced by 30 to 40~ and the cost of production and operation by about 40 to 50~.
~ lthough only certain embodiments have been described, obviously several other versions can be produced ~5 based on similar principles. The sizes and shapes of the M and V-profiles are variable, while the corruga-ted surface may differ from the illus-trated one, and the tips at join-ts of the profiles, or within the profiles may be rounded.

~3 A11 these variations do no-t change the essential charac-teristic of the invention, including the stable assembly and disassembly oE the sheets withou-t the use of adhesive, while a-t the same time the cos-t of production and opera-tion is reduced, and S the efficiency is increased.

Claims (16)

1. A packing for the biological treatment of a fluid, comprising a plurality of sheets of a synthetic resin material and horizontally abutting adjacent sheets, each of said sheets consisting of:
a plurality of substantially coplanar and identical M-section corrugations each having a pair of angularly adjoining relatively short shanks along a crest of each of said corrugations and a respective relatively long shank angularly adjoining each relatively short shank, said relatively short shanks having lengths in cross-section of substantially 1 to 200 mm said relatively long shanks having lengths in cross-section of substantially 10 to 200 mm; and wherein each of said relatively long shanks angularly adjoining a relatively long shank of an adjacent M-section corrugation along a V-section trough of the sheet;
said crests and troughs being inclined to the vertical and the inclination to the vertical being a maximum of 30°;
each of said long shanks being provided with ribs transverse to the longitudinal dimension of the respective crest and extending from the respective crest toward but terminating short of the end of the respective relatively long shank at its trough so that along a joining line of each relatively long shank with an adjoining relatively long shank a respective rib-free flat surface is formed on each relatively long shank, said flat surfaces having widths of substantially 1 to 200 mm; and said crests and troughs of said corrugations extending substantially the full heights of the respective sheets, said ribs having heights of substantially 2 to 16 mm.

2. A packing as defined in claim 1, wherein said adjacent sheetd are adhesivelessly connected together.

3. A packing as defined in claim 1, wherein said adjoining lines and centre line of said crests form angles of 5° with the vertical.

4. A packing as defined in claim 1, 2 or 3, wherein the ribs of each relatively long shank are generally of M-shape cross-section.

5. A packing as defined in claim 1, 2 or 3, wherein the ribs of each relatively long shank are generally of V-shape cross-section.

6. A packing as defined in claim 1, 2 or 3, wherein vertices at which said shanks angularly adjoin are rounded.

7. A packing as defined in claim l, 2 or 3, wherein said angularly adjoining shanks adjoin at an angle of substantially 90°.

8. A packing as defined in claim l, 2 or 3, wherein said relatively short shanks are about 2 mm in length.

9. A packing as defined in claim 1, 2 or 3, wherein said relatively long shanks are about 25 mm in length.

10. A packing as defined in claim 1, 2 or 3, wherein said flat surfaces are about 3 mm wide.

11. A packing as defined in claim l, 2 or 3, wherein said ribs are about 5 mm in height.

12. A packing as defined in claim 1, 2 or 3, wherein said ribs have flanks including angles of about 60°
with one another.

13. A packing as defined in claim 1, wherein said sheets are rectangular and have lengths and widths of substantially 500 to 3,000 mm.

14. A packing as defined in claim 13/ wherein each of said sheets has dimensions of substantially 500 x 1000 mm.

15. A packing as defined in claim 1, 2, 3, 13 or 14 wherein said sheets are turned in the same direction so that troughs of one sheet extend into crests o-f an adjacent sheet.

16. A packing as defined in claim 1, 2, 3, 13 or 14, wherein adjacent sheets are turned in opposite directions so that troughs of one sheet abut troughs of an adjacent sheet.