filtration. why filter? emitter plugging emitter wear
TRANSCRIPT
Filtration
FiltrationWhy filter?
Emitter Plugging
Emitter Wear
Causes of Emitter Clogging
• Organic material in water supply• Growth of algae and other
bacterial slimes within the lateral lines
• Silts, clays, and other inorganic particles in the water supply
• Precipitation of chemicals inside the system
Selecting a Filtration System
• Understand what is in the water
• Determine the emitter orifice size
• Determine the peak flow• Cost
Mesh
• For Drip Emitters:– Orifice diameter divided by
10
• For Spray Emitters:– Orifice diameter divided by 7
FiltrationSettling Basins
Pressure Screen Filters
Gravity Screen Filters
Centrifugal Separators
Disk Filters
Media Filters
Gravity Screen
• No backflush water• Daily manual maintenance• Lose inlet pressure• Large trash removal
Gravity Screen
Gravity Screen
Sand Separators
Disc Filters
• Often best choice for very small systems
• Manual cleaning difficult• Booster pump for automatic cleaning• Small footprint• Sand may stick
Disc Filters
Disc Filters
Sand Problems
Sand Problems
Media Tanks
• Perhaps the most universal• Often sized incorrectly• Often misadjusted
Media Filtration Design
For average water: 20-25 GPM per square foot
For extra dirty water: 10-15 GPM per square foot
ASABE?
Filtration Design
Square footage needed=
Irrigation System GPM divided by
Design GPM per square foot
Filtration Design
Typical Diameters for Media Tanks:
18 inch 24 inch
30 inch 36 inch
48 inch
Media Number Media Type
Mean Effective
Media Size Mean Filtration Capacity
(@ 15-25 GPM/sq ft)
12 Round Monterey
sand 1.3 mm .21 - .16 mm 70 – 90 mesh
16 Round Monterey
sand 0.65 .15 - .12 100 – 125
8 Crushed granite 1.5 .15 - .11 100 – 140
12 Crushed silica 1.2 0.11 130 – 140
20 Round Monterey
sand 0.5 0.11 130 – 140
11 Crushed granite 0.78 .11 - .08 140 – 200
16 Crushed silica 0.7 .10 - .08 150 – 200
20 Crushed silica 0.47 .08 - .06 200 – 250
