1. Solids Contact Clarifiers
CONTACT CLARIFIER™ & CONTRAFLO®
Presented by:
Dallas Torgersen

2. Models CONTACT CLARIFIER™ CONTRAFLO® Shaft Type “C” Cage Type “C”
Type “CS”

3. Influent Pipe Location
CONTACT CLARIFIER™
CONTRAFLO®
Side feed preferred
Bottom feed possible only with cage drive
Bottom center preferred
Side feed requires muffle ring assembly

4. Mixer Impeller Marine Propeller Outward flow pattern Atop draft tube
CONTACT CLARIFIER™
CONTRAFLO®
Impeller
Outward flow pattern
Atop draft tube
Marine Propeller
Axial flow pattern
Inside Draft Tube

5. Sludge Withdrawal Usually Concentric Usually Eccentric
CONTACT CLARIFIER™
CONTRAFLO®
Usually Concentric
Cone (shaft drive)
Annular ring (cage drive)
Usually Eccentric
Offset box sump

6. Drive Dual Shaft Drive Dual Cage Drive Roller Tooth Drive
CONTACT CLARIFIER™
CONTRAFLO®
Dual Shaft Drive
Fabricated steel housing
Precision bearing above walkway
Cycloidal reduction
Dual Cage Drive
Precision bearing
Roller Tooth Drive
No housing
Precision bearing
Roller chain turntable
Helical reduction
Mixer drive is separate from scraper drive
Grease lubricated chain
Oil lubricated gearmotor

11. Installation History >470 >1000
CONTACT CLARIFIER™
CONTRAFLO®
>470
Slightly more industrial than municipal
Greater percentage of large diameter
88% are “shaft drive”
>1000
More municipal than industrial
Greater percentage of mid-size installations
67% are Type “C”

12. Decision Tree
Use if no preference based on drive, mixer.

13. Conclusions
Having the CONTACT CLARIFIER and CONTRAFLO allows us to give customer their preference.
WesTech has more configurations and experience than any solids contact clarifier manufacturer.
The best model depends on
Drive type or mixer preference
Influent pipe location
Size