GB2050338A

GB2050338A - Water or sewerage treatment plant

Info

Publication number: GB2050338A
Application number: GB8006398A
Authority: GB
Original assignee: BYDGOSKIE B P BADAW
Current assignee: BYDGOSKIE B P BADAW
Priority date: 1979-06-05
Filing date: 1980-02-26
Publication date: 1981-01-07
Also published as: FR2458514A1; FI800937A; PL120682B1; DE3009707A1; PL216133A1; FR2458514B1

Abstract

A water or sewerage treatment plant has a flocculation chamber (1) and a sedimentation chamber (2) contained in one housing. The flocculation chamber (1) has a bottom of trapezoidal cross-section and is separated from the sedimentation chamber (2) by an overflow wall (3) and a load bearing wall (4) forming an overflow passage (5) therebetween. In its lower portion the flocculation chamber is provided with supply conduits (6) having holes directed towards the bottom of the chamber, and on the bottom of the chamber is a protrusion (7) of triangular cross- section. Above the bottom of the flocculation chamber is provided a gauze filter element (8) separated from the side walls of the chamber by pockets for recirculation of the suspension being treated, the lower portion of the gauze element terminating in baffles. The sedimentation chamber (2) has in its lower portion a sedimentation space (12) with a sludge drain (13) and in its central portion has a counter-current multi-stream pack (14) and in its upper portion has a discharge trough (15) for the cleared liquid. <IMAGE>

Description

SPECIFICATION Water or sewerage treatment plant This invention relates to a water or sewerage treatment plant, in particular of the type comprising a flocculation chamber and a sedimentation chamber.

Known plants for treating water or sewerage, wherein a flocculation chamber and a sedimentation chamber are arranged in one housing, are based on the method of "volumetric" coagulation with so called plate sedimentation being realised in multistream settling tanks. The flocculation chambers are constructed with rotary mixers or with hydraulic mixers in the form of corrugated plates. There is known a system for treating surface water, of the Dutch firm "Pielkienrood - Vimitex BV", which comprises a hydraulic flocculation chamber and a multistream settling tank, and additional equipment such as a pump for recirculating sludge, and a sludge tank. The hydraulic flocculation chamber comprises a tank filled with corrugated plates disposed vertically in three sections operating in series.

There is also known a system for partial treatment of surface water, manufactured by the West German firm "Passavant", wherein a mechanical flocculation chamber is combined with a multistream settling tank in a series arrangement symmetrical along the longitudinal axis of the system, forming two parallel flows of water submitted to the process of coagulation and sedimentation. The mixing chamber is divided into two parts by a transverse partition, and in each of these parts a mechanical mixer is installed.

The present invention provides a water or sewerage treatment plant comprising a flocculation chamber and a sedimentation chamber arranged in a common housing, wherein the flocculation chamber is provided with a bottom having trapezoidal cross-section, and is separated from the sedimentation chamber by walls forming an overflow passage therebetween, wherein the flocculation chamber is provided in its lower portion with at least one supply conduit with holes directed towards the bottom of the said chamber, and wherein on the bottom of the flocculation chamber, along the axis thereof, is disposed a protrusion, and wherein above the bottom of the flocculation chamber is disposed a gauze filter element separated from the side walls of the said chamber by pockets for recirculation of the suspension being treated, the lower portion of the gauze element being terminated with baffles.

The suspension chamber preferably has in its lower portion a sedimentation space with a sludge drain, and in its middle portion has a counter-current multistream pack, and in its upper portion has a trough for discharging the cleared liquid.

The water or sewerage treatment plant according to the invention replaces mechanical devices for mixing the liquid and recirculating the sludge, and permits the various functional units thereof to be assembled into a common sectional group, whereby the compact construction enables the plant to be installed into elements with limited space, for instance into a container.

The invention will be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a vertical sectional view of a water or sewerage treatment plant according to the invention; and Figure 2 is a sectional view of the flocculation chamber, taken along the line A-A in Figure 1.

The water or sewerage treatment plant shown in the drawings is built into one common housing in which are installed a flocculation chamber 1 and a sedimentation chamber 2. The flocculation chamber 1 has a bottom of trapezoidal cross-section, and is separated from the sedimentation chamber 2 by an overflow wall 3 and a load bearing wall 4, which in their central portion form therebetween an overflow passage 5. In the lower portion of the flocculation chamber 1 are installed two supply conduits 6 having the form of perforated pipes with holes directed towards the bottom of the chamber. On the bottom of the flocculation chamber, along the axis of the chamber, is provided a protrusion 7 of triangular cross-section.Above the trapezoidal bottom of the chamber 1 is provided a gauze filter element 8 separated from the side walls 9 of the chamber by pockets 10 for recirculation of the suspension being treated. The gauze element 8 is terminated at its lower portion with inclined plates constituting baffles 11.

The sedimentation chamber 2 has in its lower portion a one sided skew sedimentation space 12, in the lowermost point of which is installed a sludge drain 13. In the central portion of the sedimentation chamber 2 is provided a counter-current multistream pack 14, and in the upper portion of the chamber 2 is provided a discharge trough 15 for the cleared liquid in the form of a perforated pipe. The entire structure is mounted on feet 16 making it possible to stand the plant on any suitable location.

In use, the liquid to be treated is supplied to the flocculation chamber 1 through the conduits 6 together with chemical reagents and agents assisting the process of coagulation. Owing to the protrusions 7 disposed on the bottom of the chamber 1, there are obtained conditions for intensive mixing, assisting the process of rapid mixing of reagents with the liquid to be treated, which has commenced in the supply conduits, together with the recirculated sludge flowing through the overflow pockets 10. The liquid on being intensively mixed at the bottom of the flocculation chamber flows from the bottom upwards through the horizontally disposed layers of the gauze filter element 8. The gauze element 8 initiates a slow pulsating movement of the flowing liquid and its streams within the entire volume of the flocculation chamber. After the coagulation process the liquid is directed to the sedimentation chamber 2 over the overflow wall 3 and through the passage 5 below the counter-current pack 14. The thickened sludge flows from the pack 14 down into the sedimentation space 12 wherefrom it is discharged through the drain 13. After being cleared the liquid is discharged through the discharge trough 15 for further processing.

Claims

1. A water or sewerage treatment plant comprising a flocculation chamber and a sedimentation chamber arranged in a common housing, wherein the flocculation chamber is provided with a bottom having trapezoidal cross-section, and is separated from the sedimentation chamber by walls forming an overflow passage therebetween, wherein the flocculation chamber is provided in its lower portion with at least one supply conduit with holes directed towards the bottom of the said chamber, and wherein on the bottom of the flocculation chamber, along the axis thereof, is disposed a protrusion, and wherein above the bottom of the flocculation chamber is disposed a gauze filter element separated from the side walls of the said chamber by pockets for recirculation of the suspension being treated, the lower portion of the gauze element being terminated with baffles.

2. A treatment plant as claimed in Claim 1, wherein the sedimentation chamber has in its lower portion a sedimentation space with a sludge drain, in its central portion has a counter-current multistream pack, and in its upper portion has a discharge trough for the cleared liquid.

3. A treatment plant as claimed in Claim 1 or 2, wherein the said protrusion at the bottom of the flocculation chamber is of triangular cross-section.

4. A water or sewerage treatment plant, substantially as herein described with reference to, and as shown in, the accompanying drawings.