PARKSON Hycor ThickTech RDT400, Installation, Operation & Maintenance Manual, Page: 31 / 198

Opening/Closing the Rotary Drum Detention Ring Port Closures:
The port closures are a special feature of the ThickTech rotary drum thickener.
With the detention ports open the flocculated solid’s detention time in the rotary
drum is decreased. This produces higher water content output solids. With the
ports closed the detention time is increased, producing thicker output solids. This
gives you control over the amount of water removed from the thickened sludge.
Unit Drive:
Just as with the rotary drum detention ring port closures, the unit drive speed allows
an increase or decrease in thickened sludge water content. Slower speeds will
allow increased detention time permitting greater dewatering. Faster rotary drum
speeds produce reduced detention time and higher water content. Please note that
an extremely slow rotary drum speed will not allow proper water release.
Spray Header Impact Angle:
The water from the spray header impacting on the rotary drum keeps the screen
clear allowing better water removal from the mass of solids inside. You may need
to adjust the impact angle of the spray header to remove all solids from the rotary
drum screen but minimize the amount of spray water entering the rotary drum.
When the spray header water is impacting perpendicular to the rotary drum all the
solids will be removed. This may allow more water than necessary to enter the
inside of the rotary drum. Angle the spray header upward until you reach a balance
between all solids removed from the screen and a minimization of water entering
the rotary drum.
Flocculator Drive:
The purpose of the flock drive assembly is to keep the speed of the sludge in the
flock tank consistent with the sludge being introduced at the base of the tank.
This assures proper retention time in the flock tank. Set the flock drive speed
accordingly. In instances of poor mixing, such as extreme cold and very thick
sludge, the flock drive can be set slightly faster than the incoming sludge to aid in
the sludge/polymer mixing.
Shutdown and Cleaning Procedures:
1. Turn off polymer feed system.
2. Increase rotary drum speed to 60% on the control panel.
3. Continue to feed untreated sludge through the ThickTech unit until the sludge
passes through the screen and does not flow out of the discharge end of the unit.
4. Turn off the sludge feed pump.
5. Turn off the flock drive.
6. Decrease the speed of the rotary drum control to 30% and allow the spray header
to wash the unit for 30 minutes (or until clean).
7. Wash the rotary drum screen and interior of the rotary drum with a water hose to
speed up the shut down process. Wash all visible solids from the exterior and
interior of the ThickTech™ unit.
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