The invention relates to modification of two types of tube settlers used for sedimentation and thus removal of flocs In the process of water treatment. The two types of tubes are (i) Square tubes (ii) Regular hexagonal tubes. The invention is modification of Patent No. 169247. i) Modified square tubes: - The conventional square tubes are modified by inserting full length of the square tube two thin cross-sheets each sheet touching the mid points of opposite sides of the square tube, thus forming four small squares each of half the side of the original square tube. Small thin flat plates of equal size are inserted in each of the small squares diagonally dividing each small square in two equal parts, one upper and another lower. These small plates are placed at a regular spacing along the length of the tube. ii) Modified regular hexagonal tube :- The regular hexagonal tube is modified by inserting two cross-sheets in such a fashion that the hexagonal tube is divided into two equal size triangles and two equal size quadrangles. The quadrangles are divided into two triangles one upper and another lower by Inserting thin flat equal size plates in each of the quadrangle one upper and another lower along the length of the tube, at equal spacing. iii] Both the modified tubes in the invention are placed in position in the sedimentation tank such that the hopper portion of the tube forms the bottom. Both the modified tubes are performancewise better compared to those in Patent 169247. The invention does not require any mechanical (or moving) parts or electrical energy for their operation and maintenance hence useful for rural areas.
