Transcript Types of Concentrates (Water Additives)

Proportioning Systems
Proportioning Systems
• Now you know the benefits and uses of water
additives, especially Class A foam. So how
do we get the concentrate into the water?
• The following reviews various proportioning
technologies along with capabilities and
limitations of each
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Why Clubs And Racquets With
Larger Heads?
A bigger sweet spot
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The Proportioning Sweet Spot
• The range in which the proportioner can
deliver acceptable performance
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Flow range
Pressure range
Proportioning rates
Foam viscosity
Desired accuracy
• Every proportioner has a sweet spot
– Size varies by type of system
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NFPA Accuracy Requirements
• For proportioning rates equal or greater than 1%:
– - 0% to + 30% or 1 percentage point, whichever is less
• For proportioning rates less than 1%:
– - 0% to + 40%
Ratio
Allowable Range
6%
3%
Lean
1%
Rich
+
30% 20% 10%
10% 20% 30% 40%
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6%
6.0 - 7.0%
3%
3.0 - 3.9%
1%
1.0 - 1.3%
0.5%
0.5 - 0.7%
0.2%
0.2 - 0.28%
Foam Proportioner Design
• Manual systems
• Automatic systems
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Manual Foam Proportioners
• Eductors
• Around the pump systems
• Self-educting nozzles
Eductor Systems
In-Line Eductors
200 psi
Inlet
Eductor
130 psi
Outlet
Check Valve
Metering Valve
Water
Pump
Foam
Concentrate
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By-Pass Eductor
200 psi
Shut-Off
Closed
130 psi
Check valve
Water
Pump
Metering valve
Foam
Concentrate
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Eductors
• Capabilities:
– Operate over narrow range of flows and pressures
• Limitations:
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35% pressure loss
Sensitive to pressure changes downstream
Must match flow and nozzle
Nozzle height limited to ten feet
Narrow sweet spot (single flow and pressure point)
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125 gpm Eductor Cutaway
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Must Match Flow, Eductor & Nozzle
125 gpm eductor
125 gpm nozzle
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Eductor - Correct Pressure & Flow
20" of Vacuum
130 psi Outlet
200 psi Inlet
Performance reduction of 35% creates required vacuum
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Eductor - Incorrect Pressure & Flow
12" of Vacuum
140 psi Outlet
200 psi Inlet
Longer hose lay, increased elevation or nozzle restriction reduces vacuum
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Eductor - Incorrect Pressure & Flow
No Vacuum
150 psi Outlet
200 psi Inlet
Increasing restriction even more on outlet side can eliminate vacuum
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Around The Pump Systems
Around The Pump Proportioner
Foam solution from all discharges
Max. 10 psi.
Incoming Pressure
Water
Pump
Eductor
Foam
Concentrate
Shut off Valve
Check Valve
Metering Valve
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Shut off
Valve
Around The Pump Proportioner
• Capabilities:
– Foam solution available to all discharges
• Limitations:
– Maximum incoming pump pressure of 5 to 15 psi
– Average operating foam proportioning error of 1 to
1-1/2 percentage points
– Pump solely dedicated to foam operation
– Narrow sweet spot
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Around The Pump Eductor
From pump
discharge
Foam concentrate
Eductor
To pump
suction
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Around The Pump
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Around The Pump
Class A foam control
Class B foam control
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Around The Pump
“Incoming pressure
less than 12 psi”
“When flow stops,
immediately turn
metering valve off”
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Self-Educting Nozzles
Self-Educting Nozzles
Monitor
Metering Valve
Control Valve
Foam
Tank
Water
Pump
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Self-Educting Nozzles
• Capabilities:
– Large flows at 1%, 3% or 6%
– Lower pressure drop than regular eductors, 10% or
less
– Increased stream reach
– Flexibility in use, not a fixed system
• Limitations:
– Narrow sweet spot
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Self-Educting Nozzle
Foam percentage selection
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Automatic Foam Proportioners
• Balanced pressure bladder systems
• Balanced pressure pump systems
• Electronic direct injection systems
Balanced Pressure Bladder Systems
Balanced Pressure Bladder Systems
Pressure Tank
with Bladder
Three-way
Valve
Concentrate Fill Line
Water Dump
Line
Foam
Concentrate
Metering
Valve
Check
Valve
Water
Pump
Modified Venturi/
Pressure Differential Valve
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Balanced Pressure Bladder Systems
• Capabilities:
– Requires water flow to operate proportioner
• Limitations:
– Operator does not know how much foam is in bladder
– Must shut down to refill
– Water flow up to 350 gpm and discharge pressure
restrictions
– Medium Sweet Spot
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5 Gallon Portable
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Differential Valve
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Panel Mount
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Balanced Pressure Pump Systems
Balanced Pressure Pump Proportioners
Foam
Tank
Concentrate
Pump
o
r
Pilot-Operated
Balance Valve
Metering Valve
Check
Valve
Water
Pump
Check Valve
Modified Venturi
or Ratio Controller
(one per discharge)
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Balanced Pressure Pump Proportioners
• Capabilities:
– Foam concentrate flow to over 300 GPM
– Plumbed discharges capable of foam or water
– Ability to vary foam concentrate % rates by discharge
• Limitations:
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Water flow limits
Discharge pressure restriction
Low flow and low percentage operation
Medium sweet spot
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Metering Valve
ADJUSTING
KNOB
CONCENTRATE
FLOW
POINTER
PLUG
STEM
TO
DISCHARGE
PROPORTIONER
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Balanced Pressure Pump System
Metering/Shut-Off Valve
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Ratio Controller
CONCENTRATE
INLET
LOW PRESSURE AREA
SOLUTION
RECOVERY AREA
WATER FLOW
BLENDING AREA
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FLOW
2” Modified Venturi Cut-Away
Foam capabilities of 60
to 200 GPM
Water flow and pressure restrictions
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Balanced Pressure Pump System
Parts Cut-Away
Metering/Shut-off valve sets amount of
foam concentrate entering the system by
percentage selected
Ratio Controller (venturi) creates a pressure drop
allowing the foam concentrate to be pumped into the
water way
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Balanced Pressure Pump System
Panel Controls
Duplex Pressure
Gauge
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Balanced Pressure Pump System
Plumbing
Crowded pump compartment
Modified venturi or ratio flow
controller (one required per
discharge)
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Balanced Pressure Accuracy Test
Balanced Pressure Accuracy Test
125 gpm @ 125 psi
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Concentrate Flow - GPM
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14
Actual Injection Rate
12
10
Recalibrated
8
6
NFPA Upper Limit
4
2
Desired Injection Rate
0
1%
2%
Proportioning Rate - %
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3%
Balanced Pressure Pump System
Capabilities
FOAM SYSTEM OPERATING PARAMETERS
FOAM CONCENTRATE TYPES(S): CLASS A OR CLASS B
SYSTEM OPERATING PRESSURE RANGE: 75-200 PSI
DO NOT EXCEED 200 PSI OPERATING PRESSURE
SYSTEM PROPORTIONING AND FLOW RATES:
NOMINAL RATE
PROPORTIONER
SIZE
SOLUTION FLOW RATE (GPM)
0.3 - 1%
3%
6%
2
60-200
60-200
60-200
2.5
80-320
80-320
80-250
3
150-625
150-500
4
300-1250
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Balanced Pressure Pump Proportioners
Pressure drop through venturi
GPM
0
50
75
100
125
150
175
200
225
250
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Friction loss
0 psi
10 psi
12 psi
15 psi
20 psi
25 psi
35 psi
40 psi
55 psi
70 psi
Electronic Direct Injection
FoamPro Single Point Direct
Injection Proportioner
Digital Display Control
Foam
Tank
Line Strainer
Water
Tank
Check
Valves
Flow
Meter
Water
Pump
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Multiple
Discharges
Multi-Point, Electronic Direct
Injection Proportioner
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Electronic Direct Injection
• Capabilities
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Extremely accurate
No flow or pressure restriction
Indifferent to changes in flows and pressures
Easy to operate
Re-supply foam without interruption
Dual foam capability with automatic presets
Commences operation immediately
Ideal CAFS interface
Broad sweet spot
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Operation
• Commences operation with
the push of the RED button…
• Or throw of a switch
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How Accurate?
FoamPro Model 3060 Accuracy
1000 gpm @ 200 psi
80.0
Concentrate Flow - GPM
70.0
60.0
NFPA Upper Limit
50.0
40.0
30.0
Actual Injection Rate
20.0
Desired Injection Rate
10.0
0.0
0.5
1.0
2.0
3.0
4.0
Proportioning Rate - %
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5.0
6.0
Flow Comparison
Balance Pressure & Electronic Direct Injection
Pipe
Size
Flow Range
Electronic Direct Injection
(Max Acc)
(Max Rng)
Bal. Press.
2"
60 - 200
15 - 520
5 - 625
2-1/2"
80 - 320
20 - 750
8 - 900
3"
150 - 625
30 - 1,150
12 - 1,380
4"
300 - 1,250
55 - 1,980
20 - 2,380
No restriction permits maximum flow
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What To Consider-Proportioners
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Required range of flows and pressures
Proportioning percentage rates
Foam capable discharges
Foam viscosity
Allowable pressure drop
Operating conditions
– Hose length, elevations, etc.
• Accuracy requirements
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