Theory and Practice in the Filtration of Water

Walter Clemence
1916 Proceedings of the Institution of Mechanical Engineers  
Open sand-filters for purifying waters for potable purposes have now been in use for nearly a century, and since 1830 they have been continuously used in connexion with the London Water Supply.. The first sand-filtration plant, designed by James Simpson for the Chelsea Water Company, consisted of decanting basins in which the raw water could be kept a t rest for twelve hours, and open filterbasins in which a layer of fine sand 2 feet 6 inches deep was placed on a bed of gravel of about the same
more » ... l of about the same thickness. In the gravel bed brick collecting drains with arched covers were constructed. These large drains were found to induce a too rapid flow of the water through the sand immediately over them, and in later practice smaller drains were used which were distributed over the whole area of the floor of the filter to secure an even speed through the bed. During the last twenty years what is known as the " mechanical filter" has been introduced, in which the arrangement of the filtering materials differs little, in section, from that adopted in open sand-beds, but the water under treatment is passed through [THE I.MEcH.E.] R 2
doi:10.1243/pime_proc_1916_090_015_02 fatcat:g23v4mewezctho6c7ltjrfqwj4