Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations LittleInch on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Anthracite below troughs?

Status
Not open for further replies.

Pump2005

Civil/Environmental
Joined
Jan 14, 2006
Messages
72
Location
US
What is the correct depth that anthracite media should be below the troughs in a gravity filter? I'm thinking 4"-6".
 
If it is anthracite, I assume it is a dual media filter. You need to work out the bed expansion for all the types of media during the backwash, or the re-grade wash if you are doing one. Once you have the bed expansion, assuming you have a reasonably low weir loading rate, 100mm-150mm above the top of the expanded bed should be alright.
 
4'6" sounds a little on the high side. Sand filters expand about 30% bed of depth and anthracite filters expand about 40% of bed depth at maximum backwash rates.

Anthracite filters would need a minimum freeboard of approximately 50% anthracite bed depth.

 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top