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Recent content by RRichardson

  1. RRichardson

    hydraulics for a FOG vortex separator

    As a follow-up to my previous post, I figured out what parameters are actually needed to design this vortex separator: angular velocity and settling velocity. The whole purpose of the vortex is to allow heavy debris to settle. So I found a technical article on the ASCE library that will allow me...
  2. RRichardson

    hydraulics for a FOG vortex separator

    I have this idea to adapt what is common in storm water practice (vortex separation), to fats, oils and grease screening before being pumped into anaerobic digesters. The only difference is that I have no intention of capturing the volatile stuff, the FOG. The vortex will be used to capture...
  3. RRichardson

    Air valves versus gooseneck? Secondary effluent...

    We'll be running an experiment today to measure basin levels and try to determine what our actual head loss is. It is unlikely there will ever be any significant surges... the flows appear to be subcritical.
  4. RRichardson

    Air valves versus gooseneck? Secondary effluent...

    The main issue is that the water level would never reach the float in an above ground air release valve due to a lower HGL. There are commercially available underground air release valves, but I have a feeling these are quite expensive. I think it would be best to install the vent instead, with...
  5. RRichardson

    HDPE Clean outs

    I'm not sure. But in my City, I have seen pressurized manholes. Force mains should be self cleaning. However, if a hydro truck needs to clean the main, the typical reach is limited to 400 feet. You should have some type of access every 400 feet for cleaning.
  6. RRichardson

    Sizing (submerged) bypass conduit

    Thanks bimr for the examples
  7. RRichardson

    Air valves versus gooseneck? Secondary effluent...

    Stanier, Thanks for the reply. Secondary effluent doesn't have much odor relative to primary effluent. Also, we're in a canyon so odor isn't much of a concern. I don't think there are any surge issues either. The primary reason for having an air release in this particular situation is to...
  8. RRichardson

    Air valves versus gooseneck? Secondary effluent...

    bimr, Thank you for the response. Now that you mention that we don't need a combination valve, that makes sense. There is no reason I can think of to ever allow air back into the pipe. However, doesn't a typical air release valve trigger by water reaching some sort of float? The air release...
  9. RRichardson

    Air valves versus gooseneck? Secondary effluent...

    I'd like to know what the advantage is of a combination air valve versus a goose neck. The scenario is a 42 inch diameter concrete lined steel pipe that is fed by two secondary clarifiers (three at peak flows). The clarifiers drain into two basins where four vertical turbine pumps (two for...
  10. RRichardson

    Algae Growth in WWTP Clarifiers

    Our secondary clarifiers are circular and come equipped with brushes in the channels. The operators occasionally hose off the clarifiers with reclaimed plant water from the chlorine contact channels. There doesn't seem to be any algae growth in the secondary clarifiers. However, our aeration...

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