FR2473344A1 - Transportation skip for draining liq. from wet sewage sludge etc. - has raised hollow filter member extending up into skip space - Google Patents

Abstract

An open-topped skip, transporter bucket etc. of the type which is designed to drain liq. from wet sludge being carried in the skip. Within the skip space, a raised hollow member presents a perforated filter surface which extends up into material being carried. The passage in the hollow member leads down to drain holes formed in the base of the skip. The hollow member can be formed of flat filter plates, pref. a pair joined at their top edges which form a ridge extending longitudinally of the skip space. The lower ends of the plates are set apart and fixed to the bottom of the skip space. Alternatively, the hollow member can be a perforated pipe, several of which project upwards from the bottom of the skip space. The bottom of the skip space can be twin-walled with drain holes in the lower wall and hollow members feeding liq. into the gap between the twin walls. Used for draining liq. from sludge during transportation after removal from waste water purificn. plants, industrial drainage sumps etc. Improved drainage of entire contents of skip. The new skip remains robust and inexpensive.

Description

 The invention relates to a filter bucket intended in particular for the dewatering of wet sludge from wastewater treatment plants or industrial installations.

 A bucket according to the invention has walls limiting a volume open at its upper part and closed at its lower part; this volume can be closed by a flat and horizontal bottom bottom in the bucket filtration position but it can also be closed by the meeting of two oblique bottoms giving rise to no flat part. A bucket according to the invention comprises in its internal volume at least one internal filtration surface supported by at least one upright hollow carrier member whose internal volume is in communication with liquid discharge holes provided in the lower part of the bucket , preferably in the background.

This hollow carrier member can itself be supported only by the flat bottom when this exists; it can also be supported by the flat bottom and by two opposite walls of the bucket; it can still be supported by two opposite walls alone.

 The internal filtration surface can be circular; it can also be flat or be made up of several flat and / or circular parts having various orientations.

 According to a variant of the invention, the bucket can be provided, in addition, with a filtration surface associated with all or part of the flat or oblique bottoms.

 In all cases, the grab has at its bottom or on the oblique bottoms meeting line several discharge openings for the liquid phase.

 In an embodiment of the invention, the bucket is provided with a hollow longitudinal central partition, the two longitudinal faces of which are inclined to meet at the top of this partition and these faces each constitute an internal filtration surface which can be crossed by the liquid phase in the direction towards the internal volume comprised between the two longitudinal faces.

In another embodiment of the invention, the bucket is provided with several upright inner tubes whose cylindrical face constitutes this internal filtration surface.

Each internal filtration surface consists of a filter cloth that is in direct contact with the wet sludge, a support element on which the filter cloth rests. When the filtration surface is that of a central partition or an inner tube, the support element comprises angles arranged in successive planes spaced in the direction of the height with a wing directed towards the interior of the partition central or inner tube. When the filtration surface is associated with a flat bottom. or oblique it also takes a perforated sheet spaced from this bottom and supporting the support element. The latter is a trellis with large openings or a permeable sheet of fibers. Preferably, the perforated sheet is a corrugated sheet.

To clearly understand the invention, a description will now be given of several embodiments of the invention. Reference is made to the appended drawing in which
FIGS. 1, 3, 5 and 2, 4, 6 are views respectively in elevation and at the end showing the general structure of a bucket of the invention according to three equivalent variants,
- Figures 7 and 8 are side views showing the structure. of another variant of the invention shown in two positions of use,
FIGS. 9 and 10 are cross-sectional views of two buckets according to FIGS. 3 and 4 provided respectively with a longitudinal central partition and upright inner tubes,
- Figure II is a top view of the bucket of Figure 9 having parts of the bottom cut away,
FIG. 12 is a detailed view, enlarged, in section through a vertical plane of a central partition similar to that of the bucket of FIG. 9,
- Figures 13 to 15 are detailed views, enlarged, in section, of filtration surfaces used in the bucket of the invention.

The invention does not impose the general structure of the bucket used. This can be of a type known per se, designed to be easily loaded on and off of a motor vehicle. The bucket can also be of a type designed to be mounted on a wheeled cart, of the type towable by a tractor, with a possibility of tilting forwards to facilitate its emptying, under the effect of a jack for example .

In all cases, a bucket according to the invention has opposite walls two by two 1, 2 and 3, 4 which limit between them a volume 5 open at its upper part and closed at its lower part. This volume 5 can be closed by a flat bottom 6 which is horizontal in the bucket filtration position. Volume 5 can also be closed by the meeting of two oblique bottoms 6A, 6B (Figures 7 and 8) which do not give rise to any flat lower part. The walls 1, 2 and 3, 4 can be vertical or inclined towards the outside or inclined then vertical. It is preferable that the container is longer than it is wide like most known containers and that the end walls 1, 2 are inclined towards the outside (Figures 3 and 11) so that the emptying of the container is easier. 3, 4 can be vertical or very slightly inclined outwards (Figures 4 and 9 to 11).

A bucket according to the invention is provided, in its internal volume 5, with at least one internal filtration surface 7 which is erected in this volume and which extends within it from its lower part, when the bucket is in the filtration position. It is obvious that the internal filtration surface must be arranged in the interior volume 5 so as not to hinder the emptying of the bucket. For example, when the bucket is extended, it is preferable that the internal filtration surface does not achieve a transverse partitioning which would complicate the emptying when the bucket is tilted in the longitudinal direction. With this precaution, the invention does not impose anything when the number and the arrangement of the internal filtration surface 7. This is supported by an upright hollow carrier member having at least one plane or circular face or composed of successive flat and curved parts. For example, as can be seen in FIG. 10, the bucket can be provided with several upright inner tubes 8, the cylindrical face of which carries the filtration surface 7.

 Preferably, at least one longitudinal central partition 9 divides the bucket into two parts as can be seen in FIGS. 9 and 11. This partition 9 is hollow and its two opposite longitudinal main faces each carry an internal filtration surface. More preferably, as best seen in FIG. 12, the two opposite longitudinal faces are inserted towards one another to meet at the top of the partition 9.

 Whatever the structure of the internal filtration surface 7, it is supported by the bottom 6 (FIG. 10) or by the oblique bottoms 6A, 6B; it can also be supported both by the bottom 6 and by the opposite end walls 1, 2 (Figure 11). It is not excluded either that it is supported by the opposite walls only. In any case, as is understandable, the internal filtration surface 7 is a separation between the wet sludge to be dehydrated contained in the bucket and the liquid phase which has passed through this surface.

 This liquid phase is removed from the bucket immediately after it has passed through the filtration surface. For example, when it is a hollow longitudinal partition 9, this can rest directly on the bottom 6 (FIG. 12) and evacuation holes 10 can be drilled through this bottom 6, in correspondence with the internal volume. of the partition 9, between the two inclined surfaces of the latter which meet at its top. According to another alternative embodiment, the bottom 6 can be constituted as a double bottom comprising an inner sheet 60A supported above an outer sheet 603 The inner sheet 60A supports the hollow partition (s) 9 or the tubes 8 provided with internal filtration surfaces 7, and the internal volume of these partitions or tubes is brought into communication by one or more passages 11 with the volume existing between the sheet inner 60A and the outer sheet 60B of the bottom 6. The outer sheet 60B is itself pierced by several discharge holes 10.

 This second arrangement, comprising a double bottom, is symbolized in the figures by a double line representing the bottom 6. When it is a bucket with oblique bottoms 6Â, 6B meeting, each of these bottoms has the structure of a double background described above.

The use of a double-bottom bucket 6 is advantageous because it also allows this bottom to be used as a filtration surface in addition to the internal filtration surface (s) 7. For example, the internal sheet 6 (1 can be a perforated sheet 12 spaced from the outer sheet 60B by spacers 13 which can be profiles of various types, three of which are shown in FIG. 13.

The perforated sheet 12 can support, over part or all of its extent outside the space occupied by the hollow partition (s) 9 or the tubes 8, a filtration surface similar to that which is found on the partitions 9 or tubes 8. Such a filtration surface 7 comprises a filter cloth 14 directly in contact with the wet sludge and a support element 15. The latter may be a trellis with large openings (FIG. 15) or a permeable sheet of fibers reinforced or having sufficient own rigidity (Figure 14) .When this filtration surface is associated with a hollow partition 9 or one or more upright tubes 8, it is advantageous to include in the support element 15 angles 16 placed in planes successive spaced in the height direction (Figure 12) with a wing 17 directed towards the inside of the hollow partition 9 or of the tube 8. Thus, the water which has passed through the filter cloth 14 collects on the wings 17 angles and, by shot from there, it drips and falls directly on. the bottom instead of flowing along the inner face of the filter cloth 14 and, thus, reduce the filtration capacity thereof.

It is provided, according to the invention, that the hollow partitions 9 and the tubes 8 can be permanently and permanently mounted within the interior volume 5 or removably.

 Various variants or modifications can be made to the examples described above without departing from the invention. For example, the perforated sheet (12) can be a corrugated sheet offering a larger useful filtration surface, just as the internal filtration surface 7 can have a corrugated surface profile superimposed on its general planar or curved profile.

 The bucket of the invention can be produced so as to be transportable by special carrier vehicles; its useful capacity is to be fixed according to the capacity of the latter, for example 2. or 5 or 7 or 3 8 m. Several skips can be grouped and used simultaneously depending on the volume of sludge to be treated.

For example one or more skips allow to dehydrate 3 ter a volume of 1.75 to 50 m / day-sludge having a concentration in various matters of. 10 to 50 g / l.

0.2 to 6 m3 of dried sludge are then collected.

Claims (10)

BEVENDICATIONS  1) Filter bucket with walls limiting a volume open at its upper part and closed at its lower part, characterized in that it comprises in its internal volume (5) at least one filtration surface (7) supported by an upright hollow support member (8, 9), the internal volume of which is in communication with the liquid discharge holes (10) provided in the lower part of the bucket.  2) Filter body according to claim 1, characterized in that the hollow carrier member is a hollow partition (9) having at least one main face which constitutes a filtration surface (7).  3) Filter body according to claim 2, characterized in that the hollow partition (9) is a central longitudinal partition having two opposite longitudinal faces inclined towards one another and joining at the top of the partition. 4) Filter bucket according to claim 1, characterized in that the hollow carrier member is constituted by at least one upright tube whose cylindrical face is a filtration surface (7).  5) Filter body according to claim 1, characterized in that it is closed at its lower part by a flat bottom (6). 6) Filter body according to claim 1, characterized in that it is closed at its lower part by the meeting of two oblique bottoms (68,6B),  7) Filter body according to any one of claims 5 6 characterized in that the hollow carrier member is supported by the flat bottom (6) or the oblique bottoms (6A, 6B). 8) Filter bucket according to claim 7, characterized in that the flat bottom or the oblique bottoms each comprise an inner sheet (60A) and an outer sheet (60B), these two sheets being spaced, the volume existing between these two sheets ( 60A, 60B) being in communication with the internal volume of one or more hollow members and the evacuation holes (10) being drilled in the outer sheet (603). 9) Filter bucket according to claim 9, characterized in that the flat bottom or the oblique bottoms cotprendent an inner sheet (60A) which is at least on part of its surface a perforated plate (12) supporting a filtration surface (7 ).  10) Filter bucket according to claim 1, characterized in that the filtration surface (7) comprises a filter cloth (14) and a support element (15) having angles (16) spaced apart in the height direction with a wing (17) directed towards the interior of the hollow orant (8, 9).