Clarifiers: Making What You Have ….. Work Better!
By: John Esler, P.E., President
Clarifiers, Inc. Enfield, NH
Clarifier Configurations …..
l Basic Rectangular l Gould Type II Rectangular l Basic Circular (CFPO) l Peripheral Feed (PF/PO) l Peripheral Feed (Spiral Flow) l Square
Always Think in Terms of the…..
l Flow Pattern !!!! l Influent Structure l Effluent Configuration l Sludge Collection
Basic Rectangular ….
1. Balance Flows!! 2. Think BAFFLES! 3. Modify the launders 4. Modify the Influent Structure
Golden Heart Test Baffle Loca2ons
100’
20’
30’ 60’
15’ 13’
O O 14’ Idler
Sprocket
7’ +/- Drive
Sprocket
34’ 34’
Figure 3
15’ 13’
O O
26’ 26’ 26’
#6
#5
#4 New
Influent Nozzles only
New flow measurement
flume (typical)
Block rear weirs
(typical)
0
50
100
150
200
250
300
350
0 50 100 150 200 250
Dye Co
ncen
tra-
on
Time (minutes)
Clarifier Dye Curve Comparison at 1.3 mgd Flow Rate SOR = 650 gal/sq H/day
Clarifier 3 Clarifier 4 Clarifier 5 Clarifier 6 Clarifier 7
B1
Theore2cal D.T. = 245 minutes Opera2ng D.T. : Clar #3 = 44 minutes (Control) Clar #4 = 71 minutes Clar #5 = 125 minutes Clar #6 = 104 minutes Clar #7 = 37 minutes (Control)
#5
13’ SWD
Typical Cross-Section Clarifiers #1 thru #5
13’ SWD 13.5’
Depth @ hopper
11’ typ spacing
85’ 165’ 56’ 120’
2’6”
sidewalk roadway
Baffles in Clarifier #4
only
Clarifier 1 - 5 Detention Time Comparisonat Normal Flow
0
50
100
150
200
250
300
350
0 50 100 150 200 250
Time (Minutes)
Dye
Rea
din
g
Clarifier 1 Clarifier 2 Clarifier 3 Clarifier 4 Clarifier 5
Clarifier Actual D.T. Theo D.T. #1 122 min 254 min #2 123 min 259 min #3 134 min 257 min #4 ** 164 min 271 min #5 127 min 271 min
2
3
1
4
7
5
1 2 3
120’ +/-
33’ +/- 33’ +/- 33’ +/- 20’ +/-
Face of Influent Baffle
20” Typ
NYC-Wards Is. Recommended Baffle Locations
Basic Circular Clarifier:
l Balance Flows! l Modify Launders l Modify Inlet l Add Baffles? l Improve Sludge Collection?
34
We added a new EDI with
“opposing jet” nozzles to
Clarifier 3A …..
And gained at least 10 mgd MORE
capacity per clarifier!!
38
8-sided Crosby Cylindrical Baffle
AKA the Kessler-Esler Baffle
(Franklin, NH; New Haven, CT; Atlanta, GA; Jamaica, NYC)