GB2363069A

GB2363069A - Device for manoeuvring a cover or membrane of the entire surface of a pool

Info

Publication number: GB2363069A
Application number: GB0117689A
Authority: GB
Inventors: Fabrice Schaack
Original assignee: Suez Lyonnaise des Eaux
Current assignee: Suez Lyonnaise des Eaux
Priority date: 1999-02-05
Filing date: 2000-01-28
Publication date: 2001-12-12
Anticipated expiration: 2020-01-28
Also published as: FR2789425B1; GB0117689D0; FR2789425A1; WO2000046469A1; AU2299600A; GB2363069B

Abstract

The invention concerns a device for manoeuvring a cover (1) or a membrane on the entire surface of a pool (2), characterised in that it comprises a gantry (3) for setting up and removing at least a cover (1), comprising two frames (4) mobile on a guide system (5) located along two substantially parallel sides of the pool (2), and a drum (6) or mandrel connected by its ends (7, 8) to each of the frames (4), the assembly being actuated by motors (10, 18) to ensure simultaneously a translating movement of the gantry (3) and a rotating movement of the drum (6).

Description

2363069 Device for manoeuvring a cover or membrane over the entire surface

of a pond The present invention relates to a device for covering or uncovering a pond or receptacle intended to receive or contain a liquid such as notably water intended for human consumption.

It relates more particularly to a device which is to provide the handling of a cover over a biological filter.

In fact, in the field of drinking-water treatment, biological filters are used, commonly referred to as slow filters since the speed of the fluid contained in the filter is very low, around a few tens of centimetres per hour, these filters ensuring the production of water of very good quality.

These filters usually occupy a large surface area on the ground, which may be as much as several hundreds Of M2 and include a layer of a filtering material several centimetres thick, generally consisting of river sand, responsible for retaining the impurities initially in suspension in the water.

Naturally, to ensure correct functioning of the filter, it is necessary to clean at least the surface layer of this filter in order to restore to it all its efficacy. This cleaning takes place at regular intervals; nevertheless these operations are laborious and require a prior drainage of the filter, consequent equipment, a large amount of labour and sometimes, when a layer of filtering material is replaced, a 2 not insignificant materials cost. It is therefore sought to optimise the frequency of cleaning.

In addition, these filters, because of their extent, have a large free surface exposed to environmental attacks (air, rain, dead leaves, contamination of all kinds of animal, vegetable, natural and/or artificial origin etc). These attacks are even more appreciable during sunny periods. This is because there is then combined, with these traditional contamination phenomena, an organic contamination related to an increase in matter in suspension, notably algae, associated with a variation in the oxygenation level of the water. This reduction in the quality of the water undoubtedly gives rise to an increase in the frequency of cleaning of these filters.

It has therefore been sought to limit or reduce this organic contamination by interposing, between the environment and the water, a barrier which limits or interrupts exchanges between the two media, this barrier being for example a cover produced from plastics material, notably of the PVC or polyethylene type, incorporating cushions of light material in order to ensure that the whole floats.

Nevertheless, as is necessary to allow access to the pools thus covered in order to clean them at regular intervals, systems have been developed for taking back the cover and its floats from one of the edges of the pools.

In the known systems, the cover is generally mechanically fixed to the walls of the pool and allows only reduced access to it (through a manhole) or only after lengthy and tedious manoeuvring. In addition, for systems using floating covers, these are either manually deployed, which prohibits 3 large surface areas, or pulled by a mechanical means such as a drum system, which remains immobile with respect to one of the edges of the pool, with or without guidance of the cover on the edges, which requires partial rigidity of the cover, making the system very complex.

The present invention therefore aims to mitigate these drawbacks by proposing a device for manoeuvring a floating membrane or cover providing their installation or removal, without effecting traction movements over the entire surface of the pool.

To this end, the device for manoeuvring a cover or membrane over the entire surface of a pool, including a gantry for installing and removing at least one cover, this comprising on the one hand two chassis able to move on a guidance system placed along two substantially parallel sides of the pool, and on the other hand a drum or spindle connected by its ends to each of the chassis, characterised in that there are interposed, between the motors providing the longitudinal movement of the gantry and the motors providing the rotation of the spindle, synchronisation means so as to simultaneously provide a translation movement of the gantry and a rotation movement of the drum, in order to allow the winding or unwinding of the cover, which is produced from a material whose density is less than that of the medium which it is to cover, such as notably a plastics material in the polypropylene family.

Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the accompanying drawings, which illustrate one example

4 embodiment thereof with no limitative character. In the figures:

- Figure 1 is a view in section and front elevation of the device which is the object of the invention; - Figure 2 is a view in section and side elevation of Figure 1; - Figure 3 is a perspective view of the device referred to in Figures 1 and 2; - Figures 4 and 5 are detail views illustrating the method of attaching the membrane to the pool; - Figure 6 is a detail view of one of the chassis of the gantry, illustrating the energy supply.

According to a preferred embodiment of the device which is the object of the invention, this has a membrane 1 or cover whose deployed surface area corresponds substantially to that of a pool 2 which it is wished to cover, this membrane 1 being preferentially produced from a material whose density is less than that of the medium which it is to cover, such as notably a plastics material in the polypropylene family. This material must in fact be approved by the health authorities, since it is in contact, in this particular type of application, with water intended for human consumption.

Naturally, when this membrane 1 or cover is intended to cover pools of very large extent, it will easily be understood that the device which is the object of the invention, which will be described below, may include several elements or gantries 3 making it possible to use several covers 1 as described above.

According to one advantageous characteristic of the invention, the device has a gantry 3 for installing and removing at least one cover 1, this comprising on the one hand two chassis 4 able to move on a guidance system 5 placed on two substantially parallel sides of the pool 2, and on the other hand a drum 6 or spindle connected by its ends 7, 8 to each of the chassis 4.

These chassis 4 are produced by assembling, notably by screwing, welding or nesting, metallic beams or plates, widespread on the market, so as to form a self-supporting structure with a profile which is substantially, but not limitatively, triangular.

The base 9 of this chassis is provided with means 10 for providing the connection with the guidance rails 5 placed laterally; it is a case notably of wheels or rollers when the rail is smooth, or pinions then able to mesh in a rack forming a rail.

Naturally, these means 10 of connection with the guidance system 5 are moved by motors 11 also carried by the chassis 4, it being understood that it is possible to interpose, between the motors 11 and the connection means 10, other members 12 having a kinematics for providing gear reduction and synchronisation between the different motors.

The top 13 of each of the chassis 4 has a casing 14 forming a bearing for guiding each of the ends 7, 8 of the central shaft of the drum or spindle. This casing 14 has notably selflubricated bearings or roller bearings, thus limiting friction when the spindle 6 rotates.

6 In a similar manner, the spindle 6, roughly cylindrical or polygonal in shape, is produced from an assembly of a plurality of metallic beams and parts connected together by any appropriate means.

The structure, notably welded, of the spindle is sufficiently rigid between its two lateral supports 7, 8 to absorb the torsion forces related to the rotation thereof. Thus, for example, the structure of the spindle can include a cylindrical core 15 on which there cooperate a plurality of reinforcing pieces 16 forming booms, and at the periphery of which there are connected a plurality of girders 17 forming the winding surface of the membrane.

The central core 15 of the spindle 6 has, at its ends 7, 8, lengths cooperating with the bearings positioned at the top of the lateral chassis of the gantry.

In addition, provision is made for providing the drum 6 or spindle with means for ensuring its rotation, in one direction or the other, so as to allow the winding or unwinding of the membrane 1 or cover initially coiled around the peripheral surface of the spindle.

This means can notably be at least one electric or hydraulic motor 18, fixed to the lateral chassis 4 supporting the spindle 6, and where the output shaft of each of these motors 18 meshes with a ferrule 19 fixed to the spindle.

The movement transmission can be effected as a variant by means of a system of pulleys and belts or by a train of gears or by any equivalent system.

7 Since it is necessary to combine the translation movements of the gantry along the pool with respect to the rotation movements of the spindle, in order to prevent the gantry providing a traction movement on the cover, but rather that it acts so as to raise or lower the cover on the pool progressively, during its translation, in one direction or the other, there are interposed, between the motors 11 providing the longitudinal movement of the gantry 3 and the motors 18 providing the rotation of the spindle 16, synchronisation means 20 including an automatic control box (it may be a case notably of an optical system taking fixed references on the edges of the pool and which acts on the speed of rotation of the different motors so as to synchronise the respective forward movements).

As a variant, these synchronisation means 20 are adjusted manually by the operator, who acts, in one direction or the other, for example on the speed of movement of the gantry, the speed of rotation of the spindle remaining constant.

In addition, the motors for driving 10 the gantry 3 and rotating 18 the spindle 6 are preferably electrical or hydraulic, the energy being supplied by an electrical generating set or a hydraulic unit (driven by a petrol, diesel or gas engine) fixed to the gantry, or by solar panels.

According to another characteristic of the invention, provision is made for the end which is to be connected to the spindle 6 to have a plurality of eyelets 21, uniformly distributed over the length of the side forming the end, these eyelets 21 allowing the connection of a plurality of cords 22, themselves connected to the superstructure of the spindle 6.

8 In a similar fashion, the sides of the membrane, in relationship with the edges of the pool, are provided with a plurality of means 23 of connection with or securing to the masonry forming the walls of the pool, so as to prevent any contamination of the latter by foreign bodies and also to prevent any accidental fall.

For example, it may be a case of eyelets uniformly distributed at the periphery of the membrane, these being connected to hooks 24 placed opposite on the masonry.

According to yet another characteristic of the invention, in order to prevent the stagnation of rainwater or residues on the surface of the membrane, the form and profile of the latter are such that it has a hollow area, notably at its centre or in a corner of the floating surface, which drains this water and these residues.

The material collected is then taken up by a pipe and discharged by a pump situated on the edge of the filter. This arrangement relieves the operators of the need to walk on the membrane.

The invention as described above offers many advantages, notably by virtue of the mobile gantry; it is possible to cover considerable surface areas all in one piece by means of a membrane using a small number of operators, which allows rapid access to the pools, by retracting the membrane, far from the filter.

This system can be used for covering any pool containing a liquid, which has to be protected from the action of light 9 and/or which has to be thermally insulated and/or protected against access or falls of persons and foreign bodies.

As a variant, it is possible to provide the gantry between these two lateral chassis with gratings provided with parapets allowing operators to pass and be transported along the pool for pool cleaning operations.

Naturally the present invention is not limited to the example embodiments described and depicted above, but encompasses all variants.

Claims

1. Device for manoeuvring a cover (1) or membrane over the entire surface of a pool (2), including a gantry (3) for installing and removing at least one cover (1), this comprising on the one hand two chassis (4) able to move on a guidance system (5) placed along two substantially parallel sides of the pool (2), and on the other hand a drum (6) or spindle connected by its ends (7, 8) to each of the chassis (4), characterised in that there are interposed, between the motors (11) providing the longitudinal movement of the gantry (3) and the motors (18) providing the rotation of the spindle (6), synchronisation means (20) so as to provide simultaneously a translation movement of the gantry (3) and a rotation movement of the drum (6), in order to allow the rolling up or unrolling of the cover (1), which is produced from a material whose density is less than that of the medium which it is to cover, such as notably a plastics material in the polypropylene family.

2. Manoeuvring device according to Claim 1, characterised in that, in order to prevent the stagnation of rainwater or residues on the surface of the membrane (1), the form and profile thereof are such that it has a hollow area, notably at its centre, or in a corner of the floating surface, which drains this water and these residues.

3. Manoeuvring device according to one of Claims 1 or 2, characterised in that provision is made for the end of the membrane (1) which is to be connected to the spindle (6) to have a plurality of eyelets (21) uniformly distributed over the length of the side forming the end, these eyelets (21) allowing 11 the connection of a plurality of cords (22), themselves connected to the superstructure of the spindle (6).

4. Manoeuvring device according to any one of the preceding claims, characterised in that the structure of the spindle (6) includes a cylindrical core (15) on which a plurality of reinforcing pieces (16) forming booms cooperate, and at the periphery of which there are connected a plurality of girders (17) forming the winding surface of the membrane.

5. Manoeuvring device according to any one of the preceding claims, characterised in that the gantry (3) has, between thes two lateral chassis (4), gratings provided with parapets enabling operators to pass and be transported along the pool (2) for pool cleaning operations.