FR2860785A1 - Separating and clarifying plant for water containing mineral materials such as sand and gravel, has tank with scoops on rotating wheel connected to endless screw - Google Patents

Abstract

A separating/clarifying plant, comprising an endless screw to remove coarse materials and a treatment unit, includes a tank to receive the contaminated liquid containing a driven rotary wheel with scoops on radial arms that raise the liquid from the bottom of the tank and discharge it at the top into the endless screw via a hopper. The hopper is located at the lower end of the endless screw and has one wall that acts as an overflow for the liquid. The separating/clarifying plant, comprising an endless screw to remove the coarser materials and a treatment unit, includes a tank (1) to receive the contaminated liquid containing a driven rotary wheel (13) with scoops (16) on radial arms (15) that raise the liquid from the bottom of the tank and discharge it at the top into the endless screw via a hopper. The hopper is located at the lower end of the endless screw and has one wall that acts as an overflow for the liquid. The top of the tank is located at ground level, and it has an overflow linking it to a second tank with pumps.

Description

The invention relates to a separation and clarification installation

  liquids loaded with sand, gravel and / or other mineral compounds and, more particularly, the receiving and feeding part of such an installation intended for the treatment of liquids coming from the cement industry and

concrete.

  The applicable regulations, particularly in France, require the treatment and recycling of liquids from the manufacture of concrete and cement, as well as liquids from the washing of production facilities and / or vehicles carrying these products and designated, the most often, under the terms of concrete pumps or routers.

  Treatment plants are known for separating sand and gravel from liquids loaded with cement, where the latter, called laitances, are subjected, for example, to settling followed by cycloning and spinning before passing through a filter press. At the end of this treatment, the liquids were separated into two phases: a solid phase comprising sands, gravel and milt slabs composed mainly of cement, and a liquid phase comprising reusable water in the production facilities and washing.

  To bring the liquids to be treated to the treatment units, it is known to deposit them in a feed hopper of a worm which ensures a first separation of the largest sand and gravel. An unloading dock raised above the hopper is often required.

  Such an installation can not operate continuously, the feed of the hopper being intermittent. It is not suitable for treating all liquids from the concrete production unit and transport vehicles.

  It is to these drawbacks that the invention more particularly intends to remedy by proposing an installation equipped with a reception and supply device adapted to receive all the liquids coming from the production site and to ensure continuous operation of the device. 'installation.

  For this purpose, the subject of the invention is an installation for separating and clarifying charged liquids, in particular in sand, gravel and / or other inorganic compounds, comprising a worm and means for treating liquids, characterized in that it comprises a tank for receiving charged liquids and a drive device capable of moving at least one charged liquid collection member between a first position, where the body plunges into the receiving basin and collects charged liquid, and a second position, wherein the collection member discharges the loaded liquid into a feed means of the worm.

  Thanks to the invention, it ensures, in addition to a continuous receipt of effluents, a continuous supply of the first step of the treatment process. A buffer of liquids to be treated is created, which ensures a continuous operation of the installation.

  According to advantageous but non-obligatory aspects of the invention, the installation incorporates one or more of the following features: the drive device comprises a wheel, driven by a motor member and equipped on its circumference with several collection members in the form of of buckets. Advantageously, these buckets are connected to the wheel by arms extending radially outwards.

  The means for feeding the worm is a hopper situated at the bottom of the screw, one of the walls of the hopper being provided with a spillway in the receiving basin.

  As a variant, the drive device comprises an endless chain.

  - The opening of the receiving basin is flush with the ground, and the basin is equipped with an overflow opening into a second basin provided with liquid recovery means.

  - The receiving basin has a shape such that its bottom is located at a substantially constant distance from the opening of the collection members, during the movement of the latter.

  - The training device is partially immersed in the basin.

  The collection members are provided, in the vicinity of their opening, with a scraping member, in particular a blade or teeth.

  - The axis of rotation of the wheel is movable, in particular by at least one spring or cylinder.

  The collection members pass into a washing zone as they move between the second liquid discharge position and the first position.

  The invention will be better understood and other advantages thereof will appear more clearly in the light of the following description of an embodiment of a receiving device and power supply according to the invention, given only by way of example and with reference to the accompanying drawings in which: - Figure 1 is a schematic representation of a liquid treatment plant according to the invention, - Figure 2 is an enlarged view of the receiving and liquid supply device shown in Figure 1, - Figure 3 is a partial section of the drive member and a part of the receiving basin according to the plane III III in Figure 2 and, - Figure 4 is a perspective view of a liquid collection cup.

  The installation shown in FIG. 1 comprises a zone of arrival of the loaded liquids to be treated, this zone being located at ground level and connected to gutters. This zone is connected with a first portion, forming a weir, of a receiving basin 1. This receiving basin 1 has a section, in the plane of Figure 2, generally configured V flat bottom. In section in the plane of Figure 3 its bottom is generally configured in an arc. This basin 1 communicates, at one of its sides, with a second basin 2, an overflow 3. This second basin 2 receives two pumps 4, operating alternately, and adapted to send the water, rid of their more large elements but still loaded, to a first part of the plant equipped with spin 5, cycloning 6, and decanting means 7.

  At the end of this part of the treatment, the solid phase is evacuated to a zone Z 'of storage, as represented by the arrow Fi. The liquid phase continues the treatment, for example, decantation and thickening in a tank 8 and then a passage in a filter press 9 which makes it possible to obtain cement slabs 10.

  The clarified and decanted water obtained at each stage is reusable in the concrete manufacturing and / or washing process of the various parts of the treatment, recycling and production facilities, including for the washing of vehicles.

  Above the basin 1 is positioned a worm 11 provided with a feed hopper 12. This hopper has walls of different dimensions. One of these 120 walls, the smaller one, has a weir 121.

  At one end 11A of this screw 11, the coarser sands and gravels are evacuated to the zone Z 'where they join those resulting from spinning and cycloning. The liquids, still loaded with relatively fine particles, fall back into the pond 1 through the spillway 121 and, via the overflow 3, pass into the secondary basin 2 where the pumps 4 ensure their path through the rest of the installation, as explained above. A washing ramp 110, shown in Figure 1, used to wash the materials entrained by the screw 11 and maintain it in water which facilitates the drive of the materials.

  A wheel, for example, a spoke wheel 13, is disposed in the receiving basin 1 so as to be partially immersed in the latter, for example on 30 to 40% of its diameter. The axis of rotation of the wheel 13 must not be immersed to avoid any deterioration and / or corrosion. The axis of rotation 14 of this wheel 13 is arranged to be generally horizontal. The wheel 13 is rotated by a motor 13A which can be of any known type, including electrical.

  The interior of the basin 1 is adapted to the shape and dimensions of the wheel 13, so as to keep the distance D between the bottom F of the basin and the axis of rotation 14 constant overall.

  The wheel 13 carries several arms 15 regularly distributed over its circumference. These arms 15 are arranged to extend radially outwardly of the wheel 13. Buckets 16, generally in the form of triangular section prisms, are fixed at one of their triangular bases to one end. free of each arm 15. They are fixed on the arms 15 so as to extend cantilevered with respect to the wheel 13.

  On one of the edges of each opening 17 of the buckets 16, namely the one 18 farthest from the axis of rotation 14 of the wheel, the buckets are equipped with a scraper member in the form of a blade 19.

  When the wheel 13 is rotated in the direction of the arrow R in Figure 3, the buckets follow a circular path. Each bucket 16 passes cyclically in the basin 1 where it fills with liquids loaded with sand, gravel and / or other mineral compounds. The filling of the buckets 16, during rotation, is facilitated by the evacuation of the residual air thanks to the shape of the buckets.

  During this filling, the shape and dimensions of the basin 1 allow the bucket 16 to pass as close to all the points of the wall and bottom F of the basin 1. A permanent rotation of the wheel agitates the liquid in Basin 1 and to avoid a build-up of sands, gravel and cement. This is also favored by the regular and permanent scraping of the sands, gravel and / or other mineral compounds made by the blade 19 positioned on the edge 18 of each bucket 16. The speed of rotation of the wheel 13 is adjustable as a function of the amount of liquid in the basin 1 and / or the solid load Despite this agitation, the sands, gravel and / or inorganic compounds present at the bottom of the basin 1 tend to form a compact layer. In order to avoid any damage to the wheel 13, buckets 16 or any blockage of the rotation of the wheel 13 by large and / or compacted elements which may be in the bottom of the basin 1, it is possible to vary the distance d between the scraper member 19 and the bottom of the basin 1, for example by mounting the axis of rotation 14 of the spring wheel or cylinder to have some flexibility.

  By these movements of the axis 14, the filling of the buckets 16 is optimal, the latter collecting, at each cycle, globally the same amount of material.

  The filling of a bucket 16 is generally completed when it passes in the vicinity of its bottom dead center Mb during the rotation of the wheel. The bucket 16 then begins a rise allowing the evacuation of liquids out of the basin 1.

  In the vicinity of the top dead center Mh of its rotation, each bucket 16 passes over the feed hopper 12 of the worm 11 and pours into the latter its contents, the passage of the bucket 16 above the hopper 12 is performed first above the wall of larger size and above the small wall 120 provided with the weir 121. Thus the hopper is adapted to not impede the rotational movement of the buckets 16. In order to optimizing the unloading of the buckets, the feed hopper 12 and the worm 11 are arranged in a direction generally parallel to the axis of rotation 14 of the wheel. Each bucket 16 then begins a descent to the basin 1 to start a liquid collection cycle. During this descent, and while it is generally always above the feed hopper of the worm, each bucket 16 passes in a zone Z, visible in Figures 1 and 3, where it is washed, for example by high pressure jets 21.

  The liquids, freed of their charge in larger compounds, flow through the lower part 11B of the worm 11, arranged in an upward slope, and fall into the hopper 12 and, through the weir 121, into the basin 1 receiving and feeding.

  The relatively small shape and dimensions of Pond 1 make it easy to decant liquids, even if they are not loaded. The solid phase of these liquids can be easily recovered in the bottom of the basin by the buckets 16, during scraping by the blades 19. The liquid phase is, for its part, evacuated by the overflow 3 in the second tank 2 which, advantageously, is of smaller dimensions than those of the basin 1. A set of pumps 4 brings the liquid to the rest of the installation, consisting of the devices 5 to 9, these pumps operating, advantageously, alternately. This second basin 2 also acts as a buffer basin which makes it possible to easily regulate the reception of the effluents and the supply of the apparatuses 5 to 9 of the installation.

  In another embodiment, the blades 19 of the buckets are replaced by teeth.

  In a variant, the number and the shape of the buckets 16 are different.

  It is also possible in another configuration to replace the wheel 13 with an endless chain.

  In another embodiment, not shown, the buckets 16 have several orifices distributed over at least one wall of the bucket. These orifices facilitate the evacuation of the residual air during the filling phase and initiate the evacuation of liquids during the raising phase of the bucket 16.

Claims (11)

  1. Installation for separating and clarifying charged liquids, especially in sands, gravel and / or other inorganic compounds, comprising a worm (II) and liquid treatment means (5, 6, 7, 8, 9) , characterized in that it comprises a basin (1) for receiving charged liquids and a drive device (13, 13A, 14) capable of displacing at least one collection member (16) of charged liquids, between a first position (Mb), wherein said member plunges into said receiving basin (1) and collects charged liquid, and a second position (Mh), wherein said collecting member discharges the charged liquid into a supply means (12) of said worm (11).   2. Installation according to claim 1, characterized in that the driving device comprises a wheel (13), driven by a motor member (13A) and equipped on its circumference with a plurality of cup-shaped collecting members (16).   3. Installation according to claim 2, characterized in that said buckets (16) are connected to said wheel (13) by arms (15) extending radially outwardly.   4. Installation according to one of the preceding claims, characterized in that said feed means of the worm (11) is a hopper (12), located in the lower part of said screw (11), one ( 120) walls of said hopper (12) being provided with a weir (121) in said receiving basin (1).   5. Installation according to claim 1, characterized in that said drive device comprises an endless chain.   6. Installation according to one of the preceding claims, characterized in that the opening of said receiving basin (1) is flush with the ground, and in that said basin (1) is equipped with an overflow (3) opening into a second basin (2) provided with means (4) of liquid recovery.   7. Installation according to one of the preceding claims, characterized in that the receiving basin (1) has a shape such that its bottom (F) is located at a distance (d) substantially constant from the opening (17) of collecting members (16) during the movement of the latter.   8. Installation according to one of the preceding claims, characterized in that the drive device (13) is partially immersed in said basin (1).   9. Installation according to one of the preceding claims, characterized in that the collection members (16) are provided in the vicinity of their opening (17), a scraper member, including a blade (19) or teeth .   10. Installation according to one of claims 2 or 3, characterized in that the axis of rotation (14) of the wheel (13) is movable, in particular by at least one spring or cylinder.   11. Installation according to one of the preceding claims, characterized in that the collection members (16) pass in a washing zone (Z) during their movement between the second position of discharge (Mh) of the liquid and the first position (Mb).