Sludge blanket rising with increased flow.

[Pump2005]

I am in the process of increasing well output for the expected demand as the weather warms up. Problem I am having is that with each increase in gpm the blanket rises with each change. We were running more liquid alum to build up a good blanket, now the blanket seems too strong to allow correct flow through while staying stable. With the heavier solids higher in the tank they are not settling down to be blown off. Polymer dose is correct. Is my problem too much alum and what can be done without any additional chemicals?

 

[bimr]

Contact your chemical supplier and have them come in and do jar testing to determine the optimum dosage of chemicals.

 

[shahyar]

Just my thought,
Can you decrease the frequency of sludge dischrging, I mean discharge less frequently? (If you discharge it intermittently).
I presume you are talking about cold lime softening.

 

[Pump2005]

We are at the doses we are suppose to be at as far as alum and polymer. We are cutting back on the alum. What we really need is for the plant to go off for about six hours to settle the sludge blanket down in the clarifier and allow the sludge to be blown off. Problem is that one of our towers is down for painting and the plant will only go off for about 1/2 hour to 45 minutes at a time. We discharge sludge(iron)twice an hour @ 4 minutes.