Effluent Sand Filter Diffuser Whatizzit

[DrLewinstein]

The diffuser in the attached photo is part of an effluent sand filter. The filter has a filter plate into which the diffuser is attached so that the diffusers are the only means by which water can get from one side of the filter plate to the other. The sand and anthracite sit on the filter plate with a chamber underneath. The water goes down through the sand and anthracite media and somehow goes through the diffuser to get under the plate to drain out through the chamber, backwards through the backwash pumps. The backwash pumps pump water into the chamber under the plate and water for backwash comes up through the diffusers. A blower also blows air into the chamber under the plate and air also comes out of the diffusers agitation. So this diffuser is supposed to let water and air go up, and filtered water go down, but strain out the sand. Sounds ambitious to me and I don't know that this thing has ever worked.

Two questions:
1. Where could I get some new ones of these?
2. Is there a better designed diffuser that does the same thing that we could replace these with?

Thanks

 

[SteveWag]

1. Here:

http://tecpro.com.au/documents/vertical_002.pdf

2. Short answer NO, but each manufacturer says theirs is the best. The extension (drop or dip) tube extending from the threads down is for air/water mix backwash. These are used in rather cheap filters where 6-inches or more of gravel support is deemed as unneeded cost.
Steve

 

[SteveWag]

I looked a little closer at your photo. Is that organic material clogging the slots? What is the source of backwash water? Is clogging the problem or breakage? If breakage, then:

http://www.federalscreen.com/media_retention.html#Anchor-35326

Steve

 

[bimr]

In addition to stevewag's comments. This appears to be a standard strainer for a filter with an air scour backwash.

The long neck is designed to evenly distribute air across the bottom of the filter.

For best results, you should contact the original manufacturer for the replacement parts.

 

[DrLewinstein]

Thanks for your responses. The problem with the strainers is that they stop up. The way the plant is designed, if the filter is bypassed, the unfiltered effluent goes into the clearwell used for backwash, which introduces solids. Based on the design, the backwash water has to be really clean at all times or the strainers will stop up. Our plan at present is modify the bypass so that unfiltered effluent does not go into the wetwell, and then to clean them and try them again.