Posted by Mike Pilling on October 30, 2001 at 10:57:12:
In Reply to: Re: gravel bed beneath zeolite ion-exchange bed posted by Shannon on October 23, 2001 at 23:12:09:
A gravel bed is usually a good idea. Through mechanical filtration, it keeps dirt out of your ion exchange medium and also prevents channeling on backwash. One drawback is that it will reduce your flowrate by providing resistance to the flow of water through the unit.
Use special gravel designed for water treatment applications, AWWA grade.
Just for comparison, my vessels are 6' diameter by 12' high. I have (starting from bottom)
* 1.5" x 1" gravel up to dished head/shell joint
* 1/4" x 1/2" gravel, 4" thickness
* 1/8" x 1/4" gravel, 4" thickness
* 1/16" x 1/8" gravel, 4" thickness
Hope this helps.
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: : why gravel bed is laied beneath ion exchange resine. is it ordinary gravel or some special& what should be its thickness?
: I currently maintain 2 sodium zeolite ion exchange hot water polishers.
: There is no gravel bed beneath the resin. The only gravel bed is in the
: salt saturator tank for the regeneration process.