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3/18/2009
Sand Settling Lanes
Joe HarnerDept Biological & Agricultural
EngineeringKansas State University
Manhattan, KS [email protected]
Univ. of Wisconsin Study
Issue Sand MattressLameness 15 % 25 %Hock/Legs 10.4 % 24.4 %
Culling 26 % 38 %Milk Production 26,058 24,064
Assumptions $12/cwt and 500 cows
Milk Production $23,928 Lameness $7,400 Culling $18,000
TOTAL $49,300 or Gross $500/cow/year
Andy Johnson – sand worth $1.66/cwt more compared to mattress
Sand in FreestallsCleanComfortableLower Bacteria
CostHandling
Positive Attitude & CommitmentRemoval
Stacking
Separation
SLM Systems are ComplexRemoval of manureMovement to sand recovery areaSand separation Move sand to storage areaMove liquids/solids to separation unitSolids removal processMove solids to storage areaTransfer liquid to storage area
Basics of Sand Separation
Separation based on DensityWater – 62 lbs / cubic footSand – 120 to 150 lbs / cubic foot
Mi i f i di tMixing of ingredientsWater – Manure – Sand
Suspension of mixtureDilution & High Velocity
Change velocity of suspended mixtureSand settles out if done correctly
3/18/2009
Why are some sand recovey systems successful?
Reclaiming sand requires water – the more the better
Total solids content in lagoon waterOne website – 1 % total solids3 % realistic5 % trouble5 % trouble
SourcesRainwaterRoof / Extraneous Pasture PondsMilk Parlor / Sprinkler System
Additional Water Required If 100 % of Waste Stream is Diluted
Solids in Recycle Water %
Separator Efficiency
0* 30/60* 60/80*
1 204 g/d/c 139 g/d/c 78 g/d/cg g g
2 95 63 34
3 58 37 20
4 40 25 12
5 29 17 8*Percent solids recovered and solids moisture content
500 Cow Dairy
Solids in Recycle Water %
Annual Water Volume
0* 30/60* 60/80*
Manure 3,100,000 2,800,000 1,900,000
Separator 0 310,000 1,200,000
1 40,500,000 28,100,000 8,000,000
3 13,900,000 9,500,000 5,500,000
5 8,600,000 5,800,000 3,300,000
*Percent solids recovered and solids moisture content
WI Dairy Producers
1
1.5
2
2.5
3
3.5
4
4.5
5
Tota
l Sol
ids
(%)
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
1.5 1.75 2.75 3.5 4 4.5
Lago
on C
apac
ity /
Cow
Satisfaction w/ Sand Quality
10-20 g/d/c
1-2 g/d/c
0
0.5
1.5 1.75 2.75 3.5 4 4.5Satisfaction w/Sand Quality
As the solid contents in recycled water increased, satisfaction with sand quality decreased proportionally
New vs Recycled Sand
Annual Sand Usage (55 lb/stall/day)20,000 lbs or 10 tons$10/ton = $100/stall/yr
Extra Water (20 gal/dy/stall)7,300 gallon/yr/stall$0.015/gal disposal = $110/stall
If all of the sand/stall/yr goes on 1 acre for 10 years = equals ½ inch of sand added to field (about 1 dump truck load per acre)
3/18/2009
Inorganic Bedding –Recycle Sand
Scrape System – Mechanical separation
Flush Plume System – Mechanical orFlush Plume System Mechanical or gravity separation
Flush System – Mechanical separationGravity separation
Flushing Criteria
1 ½ to 2 % slopeFlush wave velocity > 5 fps (7.5 to 10 fps)Contact time of 10 secondsContact time of 10 secondsWave depth of 3 to 4 inches10,000 gpm release rate1 to 1 ½ gallon per sq ft of floor area
Dilution ratio 6 to 1 (water to SLM)
DM and OM content of sand in free stalls
96.0
98.0
100.0 Fresh Recycled
98.0 98.2 98.9 98.4
90.0
92.0
94.0%
DM Ash
DM: SE = 0.08, P < 0.05Ash: SE = 0.03, P < 0.001
Sand usage
25
30
35
40
45
e st
all/d
ay
ControlPack Mat
41.5 40.1 40.8 28.0
0
5
10
15
20
lb. s
and/
free Sand Mizer
Sand Trap
Sand retaining devices differ (P < 0.01)
3 Types of Gravity Sand Recovery Systems
Sand Trap -- KS, PASand Lane -- KS, CA, FL, GA, TX, PA, MD, IA, MN, SD, WI, MISand Beach -- VA
The challenge is once sand is in suspension to maintain the water velocity until the desired location to settle the sand – once the water velocity slows down – sand will settle and must be resuspended if it occurs in a non desirable location.
3/18/2009
Gravity Sand Recovery
Reduce velocity to 1 to 2 fps Large volume of waterChange velocity quickly at exit g y q yDrying period requiredDirty water onlyRewash “dirty” sand
Sand Trap
40 ft wide, 40 ft long, 3 to 4 ft deepSand storage basin (7 to 21 days)Manure storage when scrapingg p gOutlet pipe design critical Sand will have <3 % organic matterSand may be more moisture
Flush Wave
Ramp
24 ft flat bottom10:1 Slope
18” Drain Pipe
Sand Trap –3 to 4 ft deep
SAND TRAP
Organic Matter vs Ash (sand)
50607080
ent Ash Organic
010203040
perc
e
S. Trap Solids Earth LagoonLocation of Nutrients
3/18/2009
Sand Lane
12 ft wide, >150 ft long, 1 ft deep1/10 to ¼ % slopeSand storage (<7 days)g ( y )Redistribute dirty sand Slope & flush volume critical Sand will have <1 % organic matter
Direction of Water Flow
Sand Lane Considerations -Length vs width Existing componentsEase of cleaningStack pad location P i i f ll
Direction of Water Flow
Proximity to freestalls
20-30’
4 ft Splash Walls
20-30’
Water Flow Direction
Sand will settle where water flow is interrupted or the water velocity is
Longer lanes result in settling more of the finer sand particles
interrupted or the water velocity is reduced. Design flow velocity is 1-2 fps – less than 1 fps results in organic matter settling.
3/18/2009
125-300 ft Lane Slope0.2 to 0.25 %
Sand Dewatering Pad
30 ft min
10 – 16 ft
Width based on inlet water volume
3/18/2009
Sand Beach
Variable width, length and depth1/10 to ¼ % slopeSand storage (<45 days)g ( y )Redistribute dirty sand Counter slope critical Sand will have <1 % organic matter
Sand Stack Pad
Inflow
12 ft
50-75 ft 3-5 % slope
SAND BEACH
15-24” 15-24” 15-24”
Flush Plume – Width is a
Transition from square to round tube causes sand to settle at entrance due to change in velocity
function of water velocity and channel slope
Solid Separation
Mechanical Systems –Stationery screensRoller pressesExtrusion units
Non Mechanical Systems -Weep WallsTrenchesSmall Lagoons
3/18/2009
Solid Separation
150 lbs/cow/day @ 87 % M.C.20 lbs solids & 130 lbs liquid
20 % Removal & 60 % M.C.10 lbs removed -- 140 lbs to lagoon
60 % Removal & 80 % M.C.60 lbs removed – 90 lbs to lagoon
Flushing or Scraping Systems
Sand separatorchange water velocity and drop out sand
Solid storage basin (trench basin)settle sand and organic matter from water
Lagoon or storage pondstorage structure for fresh and flush water THANK YOU -- QUESTIONS