SLOW SAND FILTER FOR USE WITH INTERMITTENTLY FLOWING WATER SUPPLY AND METHOD OF USE THEREOF

摘要

THIS INVENTION RELATES TO A NOVEL INTERMITTENT SLOW SAND FILTER AND A METHOD OF USING THE INTERMITTENT FILTER. MORE PARTICULARLY, THIS INVENTION PERTAINS TO A NOVEL SLOW SAND FILTER WHICH REMAINS EFFECTIVE, EVEN WHEN INTERMITTENTLY OPERATED, AND WHICH CAN BE PERIODICALLY CLEANED WITHOUT DISTRUBING THE ACTION OF TEH INTERMITTENT FILTER. A SLOW SAND FILTER APPARATUS COMPRISING: A CONTAINER (12, 42) HAVING AN UPPER PORTION (14, 44) OF THE CONTAINER (12, 42), THE WATER INLET (22) BEING CONNECTED TO A SUPPLY OF WATER: A FILTER MATERIAL FILLING AT LEAST THE LOWER PORTION (16, 46) OF THE CONTAINER (12, 42), THE FILTER MATERIAL HAVING A TOP SURFACE BELOW THE WATER INLET (22); A SCHMUTZDEUKE LAYER (51) ON THE TOP SURFACE OF THE FILTER MATERIAL; A WATER OUTLET IN THE LOWER PORTION (16, 46) OF THE CONTAINER BELOW THE TOP SURFACE OF THE FILTER MATERIAL; AND A WATER LEVEL MAINTENENCE DEVICE IN THE UPPER PORTION WHICH MAINTAINS WATER IN THE UPPER PORTION OF THE CONTAINER AT A MAINTENANCE LEVEL ABOVE THE TOP SURFACE OF THE FILTER MATERIAL, THE MAINTENANCE LEVEL BEING A BALANCE BETWEEN (1) A WATER MAINTENANCE LEVEL THAT IS SUFFICIENTLY DEEP THAT WATER FALLING FROM THE WATER INTLET ONTO THE TOP OF THE WATER IN THE CONTAINER DOES NOT SIGNIFICANTLY DISTURB THE SCHMUTZDEUKE LAYER (51); AND (2) A WATER MAINTENANCE LEVEL THAT IS SUFFICIENTLY SHALLOW THAT OXYGEN FROM THE AIR ABOVE THE WATER LEVEL CAN DIFFISUE THROUGH THE WATER AND REACH THE SCHMUTZDEUKE LAYER (51) SO THAT THE SCHMUTZDEUKE LAYER (51) IS MAINTAINED IN LIVING CONDITION EVEN WHEN THERE IS NO FLOW OF WATER THROUGH THE WATER INLET.(FIG. 1).