EP0327480A1 - Extensible basin made up of prefabricated elements linked together through articulations, and construction method - Google Patents

Abstract

The technical field of the invention is that of the construction of basins for the storage or processing of liquids, like those of purification plants. The basin comprises two prefabricated rectangular panels (4) constituted from a solid core (22) of which one vertical edge is a cylindrical female groove (24) open over part (ss) of its periphery, and the other vertical edge is a male cylindrical rib (23) which is engaged in the female groove of the adjacent panel in order to form an articulation (3). Each panel can rotate through an angle ( alpha ) about its articulations in order to form basins of various capacities and to allow the subsequent increasing of the latter. The said panels are fixed horizontally on the bottom and to each other by sole pieces (27) and connecting means (28). The fluid-tightness of the articulations is ensured by an internal seal (25) and possibly by an external seal. <IMAGE>

Description

The present invention relates to extendable basins composed of prefabricated elements linked together by joints and a method of constructing these basins.

The technical sector of the invention is that of the construction of storage tanks or treatment of liquids.

One of the main applications of the invention is the construction of basins for wastewater treatment plants.

We recall that for several years, under the pressure of the evolution of the regulations concerning the discharge of wastewater and the collective awareness for the protection of the environment, many communities and industrial companies are equipped with stations. for the treatment of their wastewater, of domestic or industrial origin.

For this, different systems have been studied and implemented and still include a certain number of basins made essentially with concrete walls. The latter are generally grouped according to three functions such as, for example, in the case of bacterial bed stations, which consist of one or more decanter-digesters, then of basins containing bacterial filtration and treatment beds, and finally clarifying tanks.

The wastewater to be treated circulates from one to the other of these basins, in which they deposit at each stage part of their polluting load, so that at the outlet of the last clarifier, its composition conforms to a minimum state of cleanliness compatible with its release into the natural environment.

For that, it is necessary that the volume and especially the surface of the basins are sufficient so that these can ensure their function on the totality of the water flows which cross them and with the minimum planned efficiency. However, the flow of wastewater is essentially a function of the number of inhabitants actually residing on the places of collection of domestic wastewater, or of the production of the factory rejecting industrial wastewater. Thus, from a given situation, a wastewater treatment plant is built with basins of dimensions corresponding to the needs which define a maximum flow rate, but in the event of an increase in the permanent or semi-permanent local population, for example, the needs and therefore the flow rates increase, causing saturation and then ineffectiveness of the treatment basins.

Until now, the communities or businesses concerned can only increase the capacity of their installations by building new basins, which leads to additional investments, which some are shrinking from.

The problem is to be able to build treatment plant basins which are already, in their manufacture, easy to make and which can then be increased to follow the evolving needs of the stations for a reduced additional expense.

A solution to the problem posed, object of the present invention is a storage tank, or treatment, of liquids, of the type comprising sealed peripheral walls and an independent bottom, characterized in that said walls are composed of prefabricated rectangular panels, in plastic or metal, which panels each have, along a vertical edge, a cylindrical female groove, open over part of its periphery, and along the other vertical edge, a cylindrical male rib which is engaged in the female groove of the neighboring panel to form a hinged mechanical connection between all adjacent panels, so that it is possible to build basins of various volumes or to change the capacity of a basin and said walls further comprise, internal seals, formed by strips which are glued or welded on the internal face of said walls, straddling each articulated mechanical connection and covering the internal edge of each female groove and the male rib engaged therein.

The result is a new type of liquid storage or treatment basin.

This type of tank made from prefabricated and light panels allows, from their initial construction, rapid implementation, with a great simplification of the transport and storage of these panels and a great ease of assembly.

Similarly, the assembly of these by articulations and the relative independence of the walls and the bottom makes it possible to envisage any time to increase the capacity of the basins to follow the treatment capacity needs of the treatment plant with reduced additional investments.

The configuration of this type of basin makes their application very attractive in all stations where the increasing evolution of wastewater flows can be envisaged and for which the managers do not want to oversize their capacity from their departure in anticipation of future needs.

An interesting application is their use in stations such as the bacterial bed system which is naturally ventilated with, in particular the realization of basins containing the filtering bed, such as sand or pozzolan, and of pseudo circular shape, and those decantations or clarifiers which then have a rectangular shape.

• Les figures 1 et 2 représentent, en vue de profil et en vue de dessus respectivement un bassin de type lit filtrant à section hexagonale composé de deux hauteurs de six panneaux tels que décrits dans les figures 9 et 10.
• Les figures 3 et 4 représentent en vue de profil et vue de dessus, respectivement l'extension d'un bassin hexagonal pour augmenter son volume de plus de 80% par rajout de quatre panneaux superposés deux à deux.
• Les figures 5 et 6 représentent en vue de profil et vue de dessus respectivement, un bassin à section octogonale composé de deux hauteurs de huit panneaux.
• Les figures 7 et 8 représentent en vue de profil et vue de dessus respectivement un bassin de type clarificateurs à section rectangulaire extensible de quatre à six éléments pyramidaux.
• La figure 9 représente une coupe horizontale d'un panneau monté avec ses deux articulations d'extrémités verticales accouplées avec les deux panneaux adjacents.
• La figure 10 représente une coupe verticale de deux panneaux superposés.

The following description refers to the appended drawings which represent, without any limiting character, two examples of construction of basins according to the invention.

• FIGS. 1 and 2 represent, in profile view and in plan view respectively, a basin of the filter bed type with hexagonal section composed of two heights of six panels as described in FIGS. 9 and 10.
• Figures 3 and 4 show in side view and top view, respectively the extension of a hexagonal basin to increase its volume by more than 80% by adding four superimposed panels two by two.
• Figures 5 and 6 show in side view and top view respectively, an octagonal section basin composed of two heights of eight panels.
• Figures 7 and 8 show in profile view and top view respectively a clarifier type basin rectangular section expandable from four to six pyramidal elements.
• FIG. 9 represents a horizontal section of a panel mounted with its two articulations of vertical ends coupled with the two adjacent panels.
• Figure 10 shows a vertical section of two superimposed panels.

These exemplary embodiments describe basins according to two types of configuration, and it may be possible to produce other basins either by varying the angles between the panels to obtain any geometric shape, or by increasing or decreasing the number of these panels at the same height to increase or decrease the floor area, or by superimposing one or more panel heights to increase or decrease the volume for the same floor area.

FIG. 1 represents a schematic profile view of an initial basin 1, of hexagonal shape, containing a filter bed 6, through which the waste water flows. This basin consists of a bottom 2a which is, for example, a concrete slab of circular shape, on which is fixed a first height of six prefabricated rectangular panels 4a, 4b, 4c, 4d, 4e, 4f itself supporting a second height of six other panels 4a ′, 4b ′, 4c ′, 4d ′, 4e ′ and 4f ′ attached to the first. These two heights constitute the vertical peripheral walls of said basin 1.

All the panels of the same height are linked two by two by articulated mechanical connections described in FIG. 9, forming the six corner edges 3a, 3b, 3c, 3d, 3e and 3f common to the two superimposed heights.

All of the vertical and horizontal junctions between panels are sealed according to the means described in FIGS. 9 and 10 and the sealing of the bottom to be slab is ensured by a yoke 7.

To give more rigidity and resistance to the basin, cable belts 8 resting externally on all the panels of the same height can be tensioned by any tensioning system. Figure 1 shows by way of example two belts of cables per row of panels held at the correct height and guided by two supports 9 integral with each panel.

FIG. 2 represents a schematic view from above of said basin 1 with its bottom 2a, its six double heights of panels 4 forming its hexagonal wall with six edges 3.

The dimensions and the shape of said basin are adapted to the interior volume desired for the filter bed, itself determined by the flow of waste water which passes through it to be purified. Thus this basin initially designed for a given need could have a shape and different dimensions, with one or more panel heights, any number of panels and an arrangement of these in any form including, in particular, the regular polygons will be advantageously retained.

Figures 3 and 4 show schematically in profile view and in top view respectively the basin 1 being transformed to increase its capacity and therefore its internal volume, when the water treatment needs increase. To do this, we enlarge the surface 2b of the floor to cover to cover the new surface sought. The external cables 9 are removed and the panels 4 are detached from the bottom; for example, the joint 3c is uncoupled, then they are opened relative to each other by rotating their joints 3 and removing, if necessary, their gaskets. described in Figures 9 and 10, until the new desired shape is obtained, for example a regular octagon. We see that the floor area and therefore the volume, is increased by about 80% in this example from six to eight sides.

FIGS. 5 and 6 schematically represent in profile view and in plan view respectively the new basin 5 obtained by the extension of the basin 1 of FIGS. 1 and 2.

Indeed, from the configuration according to Figures 3 and 4, it was added four panels superimposed two by two; either according to a mode of construction 4g, 4′g, which are connected to the panels 4c and 4c ′ by engaging the male part which constitutes the edge of the ones in the female part of the edge of the others to reconstitute the joint 3c; it is operated in the same way with the panels 4h and 4h ′ which are connected on one side to the panels 4e and 4e ′ and on the other to the panels 4d and 4d ′ to form two new joints 3g and 3h respectively.

The angles between all successive panels are definitively adjusted as a function of the polygon sought, ie here in the example of a regular octagon α2 is 45 °, while in the regular hexagon of the basin 1 this angle α1 is 60 °.

The peripheral wall thus formed is then made watertight by gluing or welding against the internal face, sealing strips as described in FIGS. 9 and 10 at the level of the joints 3. The same is done for the horizontal junction between the two panel heights and we take up the yoke 7 from the bottom to cover the entire surface thereof and ensure its tightness.

Figures 7 and 8 show a schematic view from above and in profile respectively of an initial basin 10 of rectangular shape of the clarifier type supplied with wastewater by an inlet tank 12. The waters then fill by gravity flow from the secondary tanks 13a and 13b from which pipes 14a and 14b leave, of different sections and of different lengths to supply a central channel 15 with homogeneous distribution. The water then overflows in a known manner from this channel 15 between the latter and two partitions 17a and 17b , not closed at their lower part, in kinds of siphons 16a and 16b thus constituted by these partitions and the rest of the basin 10. The water settles and returns clarified to pour into a peripheral channel 18 from which it s discharged at 19. The settling sludge is deposited in inverted pyramidal elements 20 placed for example on a bottom raft 2c and supported by a framework made up of pillars 21a or of a partition ns: the sludge is then discharged through pipes 21b.

The upper walls of the basin are made up of prefabricated rectangular panels 4, connected together by articulations 3, as described in FIGS. 9 and 10, and superimposed on the elements 20. Here, the angle formed by two consecutive panels is 90 ° for the four angles of the rectangle, and 180 ° for all the other junctions.

The number of panels in the direction of the width and the length of the basin is even and the side of the inverted base of the pyramidal elements 20 is such that it supports two panels fixed and sealed with it.

Figures 7 and 8 show two examples of configuration of basins: both consist of four panels on each of the two opposite sides perpendicular to the axis of the feed channel 15, but one 10, has only four panels 4i , 4d, 4h, 4l on its two other sides, while the other 11 has six. The choice of the number of panels and corresponding pyramidal elements depends on the initial capacity need, and it can be increased later depending on the evolution of its needs. Thus, it is possible in a simple way, to pass for example from the shape of the basin 10 to that of the basin 11 by uncoupling the two articulations of angles 3p and 3s for separate the wall formed from the panels 4m, 4n, 4o and 4p; two pyramidal elements 20 supported by their framework are added and two pairs of new panels 4q and 4r are connected to the joints 3p and 3s by engaging their male and female edges, then the pelvis is closed at its end by the wall previously removed.

The assembly is then sealed by internal sealing strips as defined in FIGS. 9 and 10 and after all the horizontal connection fixings have been placed.

It is thus seen that the volume of the basin 10 is increased by 50% in this example by adding only four panels with two pyramidal elements.

Furthermore, the central channel 15, the walls 17 and the peripheral channels 18 are lengthened and in order to maintain a homogeneous supply of the basin, in particular of its extension, it suffices to add a secondary inlet tank 13c with a pipe 14c of section and length greater than the previous 14a and 14b to ensure a flow equivalent to the latter towards the extended end of the basin.

For better holding of the peripheral vertical walls, it is possible to add cable belts resting externally on all the panels and tensioned by any system of tensioners, as mounted for the basins 1 and 5 of FIGS. 1 to 6.

Figure 9 shows a horizontal section IX-IX of any of the panels 4, once installed in one of the basins 1, 5, 10 and 11, shown in the previous figures. This rectangular panel is prefabricated in light material such as plastic, reinforced or not, for example polyester and possibly metal. It consists of a solid core 22 which can be flat or wavy, and / or stiffened in its vertical and / or horizontal direction by any profile or rib. Its lower edges include a sole 27, which can be turned towards the inside of the basin as in FIG. 9, but also towards the outside or towards both.

One of its vertical edges has a cylindrical female groove 24 open over part of its periphery along a sector of angle β which will normally be taken between 90 ° and 120 °. The section this groove is preferably shown to be circular, but any shape could also be suitable, for example any regular polygon.

The other vertical edge of the panel 4 has a cylindrical male rib 23, which may be of hollow or full profile and of a shape compatible with the female groove 24, so that this rib 23 can be engaged in the groove of the neighboring panel and that the male rib of the other neighboring panel can be engaged in the groove 24 of this panel 4. The section of this rib 23 is shown, preferably in the figure, circular and concentric with the groove 24.

Once the adjacent panels are positioned with an angle α of between 90 ° and 180 ° to form the shape of the desired basin, the panels are immobilized at their lower part by the fixings 28 of the soles. An inner seal 25, consisting of strips compatible with the material of the panels, is glued or welded astride the internal edge of the groove 24 and the rib 23 engaged therein, or possibly between the two edges of the adjacent cores. 22.

A second external seal 26 can be added as a variant, in order to provide sealing security for the first internal seal 25 and to mechanically stiffen the joint 3, consisting of the groove 24, the rib 23 and the seal 25: this second joint 26 is made up of strips glued or welded astride the two outer edges of two adjacent panels 4.

FIG. 10 represents a vertical section X-X of two superimposed panels 4 once installed in one of the basins 1 or 5.

The lower sole 27 of the bottom panel allows the fixing thereof by any means such as spits 28 on the bottom of the basin which can be a raft 2 as in Figure 1, but which could be other prefabricated elements such as for basin 11 of figure 8

The sealing of the bottom can be achieved by a bonding layer 30 in resin, then a sealing cap 7 in resin mortar.

The upper sole 33 allows possible fixing of the panel 4 with the lower sole 27 of a panel superimposed 4 ′ as in FIG. 10, by any means such as bolts 29. This sole 33 is superimposable on any sole 27, and their connection is sealed by an internal seal 31 made up of strips glued or welded astride its two soles and covering the fastening means 29. A second external seal 32 can be optionally added to the outside.

Claims (10)

1. Expandable basin for storing a liquid intended, in particular for equipping wastewater treatment plants, of the type comprising sealed vertical peripheral walls and an independent bottom, characterized in that said walls are composed of prefabricated rectangular panels (4), made of plastic or metal, which panels each have, along a vertical edge, a cylindrical female groove (24), open over part of its periphery, and along the other vertical edge, a cylindrical male rib (23) which is engaged in the female groove of the neighboring panel to form an articulated mechanical connection (3) between all adjacent panels, so that it is possible to build basins of various volumes or to evolve the capacity of a basin and said walls further comprise interior seals (25) for sealing, constituted by strips which are glued or welded to the internal face of said walls, straddling each articulated mechanical connection (3) and covering the internal edge of each female groove (24) and the male rib (23) engaged therein. 2. Basin according to claim 1, characterized in that said ribs (23) and said grooves (24) have concentric circular cross sections. 3. Basin according to any one of claims 1 and 2, characterized in that said grooves (24) are open on a sector having an angular opening (β) between 90 ° and 120 °. 4. Basin according to any one of claims 1, 2 or 3, characterized in that said vertical peripheral walls consist of several heights of prefabricated elements stacked and fixed on each other sealing joints (31) covering fully horizontal links. 5. Basin according to claim 4, of rectangular shape, characterized in that said panels constituting a second height of the external walls, rest on inverted pyramidal elements (20) constituting a first height, the side of the base of which has the same width that double the horizontal side of the panels which come to rest on it, and whose slope of the walls forms an angle of more than 45 ° with the horizontal, which pyramidal elements rest on a bottom raft by a framework made up of partitions and / or pillars (21a). 6. Basin according to claim 5, characterized in that the filling of said basin is done along the largest median axis of the rectangle using a central channel (15) supplied by natural gravity flow at regular intervals by pipes ( 14) independent of increasing sections coming from the same inlet tank (12) of the waste water, so that these pipes can be multiplied during the extension of the basin in the extension of this median axis in order to maintain a homogeneous distribution of feeding over the entire length of said basin. 7. Basin according to any one of claims 1 to 6, characterized in that said prefabricated panels (4) are supported in position by peripheral peripheral cables (8), stretched and pressing on all of the panels constituting the same height . 8. Basin according to one of claims 1 to 7, characterized in that the joints (3) connecting two adjacent panels further comprise external seals (26) also playing the role of mechanical stiffener, consisting of strips and glued or welded on two outside edges of two adjacent panels. 9. Prefabricated rectangular panel (4), intended in particular to constitute a sealed peripheral wall of an expandable liquid storage basin according to any one of claims 1 to 8, characterized in that it comprises, along '' one edge, a cylindrical female groove (24) open on a sector of its periphery having an angular opening (β) between 90 ° and 120 ° and of internal cross section forming a regular polygon, and along the other edge opposite to the previous one, a cylindrical male rib (23) of external cross section forming a regular polygon, inscribable in that of the groove of the opposite edge. 10. Method for constructing expandable liquid storage basins, intended in particular for equipping wastewater treatment plants, of the type comprising a vertical wall which is placed on an independent bottom with which it delimits a basin open to the upper surface, characterized in that thin rectangular panels (4), made of plastic or metal sheet are prefabricated which have, along a vertical edge, a female cylindrical groove (24) open on a part of its periphery and along the other vertical edge a male cylindrical rib (23) and a sealed vertical wall is constructed, in the shape of a polygon adapted to the volume of basin sought by mechanically connecting said prefabricated panels one to the other, by engaging the male rib of a panel in the female groove of the neighboring panel and adjusting the angle (α) between the successive panels as a function of the desired polygon and the said wall is sealed by gluing or welding, against the internal face of said wall, vertical bands (25) placed astride the internal edge of each female groove and the male rib which is engaged therein.

Images