Conversion Factors and Formulas

Transcription

1 Conversion Factors and Formulas The following conversion factors and formulas must be learned and memorized. It may be a good idea to study three or four each day until you have learned and memorized them all pound per square inch (1 psi) =.31 feet (ft) of water. 1 foot (ft) of water = pounds per square inch (psi) 3. 1 cubic foot (ft 3 ) of water = 7.48 gallons (gal) 4. 1 gallon of water = 8.34 pounds (lbs) 5. 1 grain per gallon (gpg) = 17.1 milligrams per liter (mg/l) 6. 1 horsepower (HP) = 746 watts 7. pi (π) = square feet = sq. ft. = ft 9. cubic feet = cu. ft. = ft 3 Chemical Dosage: Formulas pounds (lbs)/day = million gallons per day (MGD) x 8.34 lbs/gal x mg/l or lbs/day = MGD x 8.34 lbs/gal x mg/l MGD 8.34 lbs/gal mg/l lbs/day = percent of available chemical Temperature Conversion: Celsius (C) to Fahrenheit (F) Celsius x = Fahrenheit Fahrenheit - 3 = Celsius 1.8 Electrical: amperes (amps) x volts (v) = watts (w)

2 Detention Time: Geometry Detention Time = A = Area C = Circumference L = Length W = Width H = Height π = 3.14 r = Radius D = Diameter V = Volume B = Base Volume Flow Rate Rectangle: A = L x W V = L x W x H Circle: C = π x D A = π(r) or A = (D) D = x r 3

3 Flow: Q = Flow rate is expressed in: cu. ft. per minute (ft 3 /min). V = Velocity is expressed in: feet per minute (ft/min). A = Area is expressed in: square feet (ft ). Q = A x V or... ft 3 /min = ft x ft/min. Q Q = A = V V A ft 3 /min x 7.48 gal/ft 3 = gal/min ft 3 /hr x 7.48 gal/ft 3 = gal/hr 1 MGD = 1.55 ft 3 /sec Area Units: Areas are measured in two dimensions or in square units. The most common unit used by a distribution operator is square feet (ft ). Rectangle: The area of a rectangle is equal to its length multiplied by its width. Example: Find the area of a rectangle if the length is 8 feet and its width is 3 feet. Area, ft = Length x width Area = 8 feet x 3 feet Area = 4 ft 4

4 Circle: The area of a circle can be written: πr. Since the diameter of any circle is equal to twice the radius, the formula for the area of circle can also be written as follows: A = π r = π r r = π 1 D D π D = D = 4 = x (D ) Example: Find the area of a circle that has a diameter of 0 feet. Area, ft = (0.785) (Diameter, ft) Area = (0.785) (0 ft) Area = (0.785) (0 ft x 0 ft) Area = (0.785) (400 ft ) Area = 314 ft or using the formula πr can also be used as follows: Area, ft = π (Radius, ft) Area = 3.14 (10 ft) Area = 3.14 (10 ft x 10 ft) Area = 3.14 (100 ft ) Area = 314 ft Volume Units: Volumes are measured in three dimensions or in cubic units. The most common unit used by a distribution operator is measured in cubic feet (ft 3 ). 5

5 Rectangle: The volume of a rectangle is equal to its length multiplied by its width multiplied by its height. Volume, ft 3 = length, ft x width, ft x height, ft Example: the length of a box is 3 feet, the width is 6 feet, and the height is 30 inches. Find its volume in cubic feet (ft 3 ). Volume = 3 ft 6 ft 30 inches 1 inches/ft Volume = 3 ft x 6 ft x.5 ft. Volume = 45 ft 3 Cylinder: The volume of a cylinder is equal to the area of the base multiplied by the height. V = πr (h) Example: A tank has a diameter of 50 feet and a depth of 18 feet. Find the volume in cubic feet (ft 3 ). Volume, ft 3 = x (Diameter, ft) x Height, ft Volume = x (50 ft x 50 ft) x 18 ft Volume = x (,500 ft ) x 18 ft Volume = 35,35 ft 3 6

6 CONVERSION FACTORS WATER OPERATOR EXAM FORMULA SHEET Rev. 8/008 Page 1 of 3 1 foot = 1 inches 1 minute = 60 seconds cfs = cubic feet per second 1 inch =.54 centimeters 1 hour = 60 minutes gpm = gallons per minute 1 gallon = 8 pints 1 day = 86,400 seconds gpd = gallon per day 1 gallon = 8.34 pounds 1 day = 1,440 minutes MGD = million gallons per day 1 gallon = liters 1 day = 4 hours mg/l = milligrams per liter 1 liter = 1,000 milliliters 1 % = 10,000 ppm ppm = parts per million 1 cubic foot = 7.48 gallons 1 mg/l = 1 ppm psi = pounds per square inch 1 cfs = 448 gpm 1 cubic foot = 6.38 pounds fps = feet per second 1 gpm = 1,440 gpd 1 cubic yard = 7 cubic feet cu ft = ft 3 = cubic feet 1 MGD = 1.55 cfs 1 gallon = 8 pints sq ft = ft = square feet 1 psi =.31 feet 1 MGD = gpm gpg = grains per gallon 1 foot = psi 1 grains per gallon = 17.1 mg/l π (pi) = 3.14 TEMPERATURE Fahrenheit ( o F) = (1.8 x o C) + 3 Celsius ( o C) = 0.56 x ( o F - 3) CIRCUMFERENCE, AREA & VOLUME Circumference (C, ft) = 3.14 x diameter (D, ft) Area of a rectangle (A, sq ft) = (length, ft) x (width, ft) Area of a circle (A, sq ft) = x (diameter, ft) Area of a circle (A, sq ft) = 3.14 x (radius, ft) Volume of a rectangle (V, cu ft) = (length, ft) x (width, ft) x (height, ft) Volume of a rectangle (V, gal) = (length, ft) x (width, ft) x (height, ft) x 7.48 gal/cu ft Volume of a cylinder (V, cu ft) = x (diameter, ft) x (height, ft) Volume of a cylinder (V, gal) = x (diameter, ft) x (height, ft) x 7.48 gal/cu ft CHLORINATION Chlorine dose (mg/l) = chlorine demand (mg/l) + chlorine residual (mg/l) Total chlorine residual (mg/l) = free chlorine residual (mg/l) + combined chlorine residual (mg/l) POUNDS, DOSAGE & FLOW Dose (mg/l) = Feed (lbs/day) flow (MGD) (8.34 lbs/gal) Feed (lbs/day) Flow (MGD) = Feed (lbs/day) dose (mg/l) (8.34 lbs/gal) Feed (lbs/day) = dose (mg/l) x flow (MGD) x (8.34 lbs/gal) Feed (lbs/day) = dose (mg/l) x flow (MGD) x (8.34 lbs/gal) % purity (decimal) Dose (mg/l) Flow (MGD) 8.34 lbs/gal 7

7 WATER OPERATOR EXAM FORMULA SHEET Rev. 8/008 Page of 3 FLOW Flow (Q, gpm) = volume (V, gal) time (t, min.) Flow (Q, gps) = velocity (v, fps) x area (A, sq ft) x (7.48 gal/cu ft) Flow (Q, cfs) = velocity (v, fps) x area (A, sq ft) DETENTION TIME Detention time (DT, min) = volume (V, gal) flow (Q, gpm) PERCENT Percent (%) = part whole x 100 Part = whole x percent 100 FLUORIDATION Fluoride Feed Rate (lbs/day) = Dose (mg/l) x Capacity (MGD) x (8.34 lbs/gal). Available Fluoride Ion (AFI) x chemical purity (decimal) Fluoride Feed Rate (gpd) = Dose (mg/l) x Capacity (gpd) 18,000 mg/l Dose (mg/l) = Fluoride Feed rate (lbs/day) x Available Fluoride Ion (AFI) x chemical purity (decimal) Capacity (MGD) x (8.34 lbs/gal) Dose (mg/l) = Solution fed (gal) x 18,000 mg/l Capacity (gpd) Chemical Formula Available Fluoride Ion (AFI) Concentration Chemical Purity Sodium Fluoride NaF % Sodium Fluorosilicate Na SiF % Fluorosilicic Acid H SiF % MISC Potassium Permanganate dose (mg/l) = 1(Iron concentration mg/l) + (Manganese concentration mg/l) Alkalinity = ml of H SO 4 x 1,000 ml of sample Hardness = ml of EDTA x 1,000 ml of sample 8

8 CHEMICAL DOSES WATER OPERATOR EXAM FORMULA SHEET Rev. 8/008 Page 3 of 3 Chemical Feed Setting (ml/min) = (Flow, MGD)(Alum Dose, mg/l)(3.785l/gal)(1,000,000 gal/mg) (Liquid Alum, mg/ml)(4 hr/day)(60 min/hr) Calibration of a Dry Chemical Feeder (lbs/day) = Chemical Applied, lbs Length of Application, day Calibration of Solution Chemical Feeder (lbs/day) = (Chem Conc, mg/l)(vol pumped, ml)(1,440 min/day) (Time pumped, min)(1,000 ml/l)(1,000 mg/g)(454 g/lb) FILTRATION Filtration Rate (gpm/sq ft) = Flow, gpm Surface area, sq ft Unit Filter Rate Volume (UFRV) = (Filtration Rate, gpm/sq ft)(filter Run, hr)(60 min/hr) Backwash Water, gal = (Backwash Flow, gpm)(backwash Time, min) Backwash, % = (Backwash Water, gal)(100%) (Water Filtered, gal) CORROSION CONTROL ph s = A + B + log(ca + ) + log (Alk) Langlier Index = ph - ph s COAGULATION AND FLOCCULATION Polymer, lbs = (Polymer Solution, gal)(8.34 lbs/gal)(polymer, %)(Sp Gr) 100% DISINFECTION Hypochlorite Flow, gpd = (Container area, sq ft)(drop, ft)(7.48 gal,cu ft)(4 hr/day) (Time, hr) Feed Rate, gal/day = (Feed Rate, lbs /day)(feed Dose, mg/l). Feed Solution, mg/l Feed Rate, lbs/day = Feeder Setting, lbs/day 4 hr/day CT, mg/l-min = (Vol, gal)(t 10 )(Free Chlorine Residual, mg/l) Flow, gpm Free Chlorine Residual, mg/l = (CT, mg/l-min) T 10, min 9