COMMERCIAL SAND FILTER

New spiral cover system which aids the operations of opening and closing. The air purge is built into the cover which can be efficient to release the air from the filter. The distance between the upper part of the sand layer and the diffuser head (''freeboard'') has been increased to ensure greater distribution of water in the filtration phase and avoid sand being spilt into he drain during backwash.The specially designed hole in the sand filter can make the sand exchanging process more convenient and efficient. In the filtering process, the filtering effect of water can be observed through the perspective hole which is designed in the sand filter.