Flow rate surface area

  • KnH
    Participant

    #848

    In the flow rate section, it mentions that a 55g drum would have a higher floe rate than a concrete sand filter because of the increase surface area.

    It says the concrete sand filter (300mm diameter = area 282744 mm of surface area) has a recommended flow rate 22-25 lph.

    If I use a plastic drum (584mm diameter = area 1071461 mm of surface area). 1071461/282744= 3.79 ratio
    3.79×22=83, 3.79×25=94, between 83-94 lpm seems kind of fast

    What would the recommended flow rate be for a continuous flow slow sand filter?

  • Eric
    Moderator

    #849

    Flow rate for any kind of slow sand filter should be in the range of 0.1 to 0.4 m3/m2/hour. The larger the area, the more flow, so it seems your calcs are more or less correct. Below my calcs:

    Round concrete filter:
    Diameter: 0.26 m
    Area: 0.0531 m2
    If 1m2 can have a maximum of 400 litres/hour flow rate, then 0.0531m2 can have maximum 21.23 litres/hour

    Metal drum filter:
    Diameter: 0.584 m
    Area: 0.2677 m2
    If 1m2 can have a maximum of 400 litres/hour flow rate, then 0.2677m2 can have maximum 107.09 litres/hour

Viewing 2 posts - 1 through 2 (of 2 total)
Reply To: Flow rate surface area
Your information:



KnHFlow rate surface area