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DAF Filter Sizing Spreadsheet

Below is link to a DAF sizing spreadsheet developed by HydroFlo Tech.

By inputting the major design criteria, you can solve for overall DAF sizing based on fluctuating solids loading.

The spreadsheet operates on Microsoft Excel 2003 or later.

DAF sizing calculations

Below is a sample shot of the spreadsheet.

HydroFlo Tech, LLC.  
The Art and Science... of Wastewater Treatment   
For more detailed information go to www.HydroFloTech.com   Available
DAF Model #'s
  Company   5 281
  Location   8 300
      11 320
This spreadsheet will calculate a DAF unit based on ppm of TSS & FOG combined, Flow rate and acceptable A/S ratio:     15 340
    20 361
      25 383
  Input   31 405
What is the combined TSS & FOG ppm content of wastewater: 3000   38 428
What is the process flow rate (gpm): 250   45 451
Lbs/Sq. Ft./Hr  (1.5 Typical) 1.5   53 475
Recycle System Pressure (in gage pressure, psi, typically 65 psig) 80   61 500
Recycle System Efficency (Typically 80.00%) 80%   70 527
Temperature (in Farenheit) 60   80 592
Selected DAF model number based on minimum required DAF unit (below) and round up to the next larger DAF model 263   90 661
    101 735
      113 815
Call 630-762-0380 to talk to a HydroFlo application engineer   125 900
      138 1,088
  Output   151 1,191
lb/gal of TSS = 0.03   165 1,301
Solids Loading ratio of TSS per min (lb); 6.26   180 1,416
Solids Loading ratio of TSS per hour (lb): 375.50   195 1,539
Solids Loading ratio of TSS per day (24 hr period): 9012.10   211 1,668
Saturation Concentration (lb air/gal H2O) at atmospheric pressure 0.0002190   228 1,805
Theoretical Air Release (lb air/gal H2O) 0.0009098   245 1,945
Minimum required Sq. Ft. in DAF Unit (Separation Chamber): 250.34   263 2,150
gpm/sq.ft. hydraulic loading rate for Selected DAF Alone 0.95      
         
Recirculation (RAD) Flow Rate Range        
Theoretical Low End Recycle (RAD) Flow Rate (gpm): 125.00   Listed at the left are the theoretical RAD flow rates. 

If these numbers are above 4, increase the selected DAF model # until the output (at the desired recycle rate) is less than or equal to 4
Low end gpm/sq.ft. hydraulic loading rate for selected DAFand theoretical RAD combined (gpm/sq.ft.): 1.4259  
   
     
Theoretical High End Recycle (RAD) Flow Rate (gpm): 275.17  
High end gpm/sq.ft. hydraulic loading rate for the selected DAFand theoretical RAD combined (gpm/sq.ft.): 1.9968  
   
     
     
     
     
     
CRITERIA: You must apply the following when sizing a DAF  
Standard Solids Loading Rate: 1.5 lb/sq. ft./hr        
Never use more than 4 gpm/sq.ft hydraulic loading rate for the DAF and RAD combined      
Acceptable Lbs Air/Lbs Solids range = 0.015 - 0.040        
We typically apply 100% of the low end RAD flow rate when BELOW - 3000 ppm      
We typically apply 75% of the high end RAD flow rate when BETWEEN 3000 - 5000 ppm    
We typically apply 100% of the high end RAD flow rate when ABOVE - 5000 ppm      
         
Formulas:        
Recirculation Flow Rate:        
(Lbs Air/Lbs Solids) x (Solids Loading Rate/min) x Theoretical Air Release      
Dimensions for (Solids Loading Rate/min):  Lbs/min        
Dimensions for Theoretical Air Release:  1000 gal/0.62 lbs. @ 75 psig and 68 degrees F    
Low end (Lbs Air/Lbs Solids) = 0.015        
High end (Lbs Air/Lbs Solids) = 0.040        
         
Conversion Factors:        
1,000 mg = 1 gr        
453.59 gr = 1 lb.        
3.785 l = 1 gal.