Langley Separation & Process Belt Press 101
Operational Training
Applying 40-Years of Experience and Process Knowledge
Belt Press 101
2
sludge inlet
dewatered
sludge outlet
wedging
roll
mixer upper belt
washing system
lower belt
washing system
upper belt
centering system
lower belt
centering system
lower belt
Tensioning
system
upper belt
tensioning
system
Belt Press Side View
July 2018 LS&P BFP Operational Training 101
• Process
• Mechanics
LS&P BFP Operational Training 101 3
Dewatering Fundamentals Belt Press 101
July 2018
• Flocculation / Conditioning
• Gravity zone
• Low pressure
• High pressure
LS&P BFP Operational Training 101 4
Process Components Belt Press 101
July 2018
Filtration Zones
LS&P BFP Operational Training 101 5
Gravity
L
Wedge
High Pressure
Linear Pressure
Belt Press 101
July 2018
Colloidal Particles
LS&P BFP Operational Training 101 6
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• Most of the particles we must remove have a negative charge.
• Shells of cationic charges form around the particles.
• The force of repulsion between the particles is stronger than the force of gravity.
• As a result the particles stay in suspension.
Belt Press 101
July 2018
Flocculation
LS&P BFP Operational Training 101 7
Suspended Solids
Polymer
Floc
-
- -
- -
-
-
-
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+
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+
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Belt Press 101
July 2018
How Polymers Work
LS&P BFP Operational Training 101 8
The primary mechanism is electrostatic attraction Attractions between positive and negative charges Analogous to magnetic attraction
Belt Press 101
July 2018
Types of Water in a Biological Suspension
LS&P BFP Operational Training 101 9
Cell walls
Intra cellular water
Free water
Cohesive Water
Belt Press 101
July 2018
• Venturi Effect
• Mechanical
• Combined
LS&P BFP Operational Training 101 10
Conditioning Systems Belt Press 101
July 2018
LS&P BFP Operational Training 101 11
Belt Press 101
• Polymer injection
• Mixing o Static
o Mechanical
• Detention time
Conditioning
July 2018
• Static o Zero detention time
o Sensitive to changes in velocity and viscosity
o Increase head loss
o Reduced effectiveness >2%
o Inexpensive
LS&P BFP Operational Training 101 12
Mixing Devices Belt Press 101
• Mechanical
July 2018
Venturi Effect
LS&P BFP Operational Training 101 13
Velocity Gradient
Laminar Flow Turbulent Flow
Polymer
Belt Press 101
July 2018
BPF WR Sludge Mixer
LS&P BFP Operational Training 101 14
Outlet
HIGH ENERGY
LOW ENERGY
Inlet
Belt Press 101
Outlet
Gearbox
Agitator
July 2018
LS&P BFP Operational Training 101 15
Venturi Effect Process Schematic
Polymer Feed Pump
Sludge Feed Pump
Belt Filter Press
Mixing Valve
Dilution Water
Belt Press 101
July 2018
LS&P BFP Operational Training 101 16
Mechanical / Combined Mixing Process Schematic
Belt Filter Press
Dilution Water
Belt Press 101
Polymer Feed Pump
Sludge Feed Pump
July 2018
IDEAL MIXING SCHEME
LS&P BFP Operational Training 101 17
Mix Tank
Venturi Mixer
SLUDGE
POLYMER
Belt Press 101
POLYMER
July 2018
LS&P BFP Operational Training 101 18
Belt Press 101
July 2018
• Distribution
• Drainage o Plows
o Support grids
LS&P BFP Operational Training 101 19
Gravity Zone Function Belt Press 101
July 2018
LS&P BFP Operational Training 101
20
sludge inlet
dewatered
sludge outlet
wedging
roll
mixer upper belt
washing system
lower belt
washing system
upper belt
centering system
lower belt
centering system
lower belt
Tensioning
system
upper belt
tensioning
system
Belt Press Side View
July 2018
Belt Press Top View
LS&P BFP Operational Training 101 21
sludge inlet
mixer
lower belt
tensioning
system
upper belt
tensioning
system
Shower Cleaning
Handwheels
Belt Press 101
July 2018
Gravity Zone Nomenclature
LS&P BFP Operational Training 101 22
Running Direction
Support Grid
Belt
Headbox
Plow (raised for cleaning)
Plow (engaged)
Belt Press 101
July 2018
Gravity Zone
LS&P BFP Operational Training 101 23
Gravity Area (ft2) = L x W
Gravity
Gravity Zone Inlet
Low Pressure Zone Inlet
W
Sludge – Belt Contact Area
L
Belt Press 101
July 2018
LS&P BFP Operational Training 101 24
WATER DRAINING
ZONE
Belt Press 101
Thickening Plows Series Arrangement
July 2018
• Provide a transitional pressure o >Atmospheric ~ 0.0
o <1st high pressure roller- 1.5 PSI
LS&P BFP Operational Training 101 25
Low Pressure / Wedge Function Belt Press 101
July 2018
Rolling Radial Wedge
LS&P BFP Operational Training 101 26
1-2 in. .
1st pressure
roll
0.2- 1.5 PSI
2.0- 3.5 PSI
Belt Press 101
July 2018
LS&P BFP Operational Training 101
27
sludge inlet
dewatered
sludge outlet
wedging
roll
mixer upper belt
washing system
lower belt
washing system
upper belt
centering system
lower belt
centering system
lower belt
Tensioning
system
upper belt
tensioning
system
Belt Press Side View
July 2018
Perforated Roller
LS&P BFP Operational Training 101 28
Belt Press 101
July 2018
High Pressure Filtration Area
LS&P BFP Operational Training 101 29
1
Area = (2 x Ri x x (i / 360) x W) i = 1
n
Ri
i
Roll
W Sludge - Belt
Contact Area
Roller
Belt Press 101
July 2018
• Linear o Expressed as PLI ( pounds / linear inch)
• Area o Expressed as PSIG
LS&P BFP Operational Training 101 30
Pressure Belt Press 101
July 2018
Calculating Area Pressure
LS&P BFP Operational Training 101 31
r1
i i = <180o
r1
T1=50
T2=50
Pa= T1
r1
50
5 = 10 PSI
10”
Belt Press 101
July 2018
• Converts linear tension (PLI) to area pressure (PSI)
• Shearing forces are created as a result of differential in tangential belt speed
LS&P BFP Operational Training 101 32
High Pressure Objectives Belt Press 101
July 2018
LS&P BFP Operational Training 101 33
Shearing Force Belt Press 101
July 2018
Shearing Forces
LS&P BFP Operational Training 101 34
= S 1 +S 2 +S 3 .......S 10
R 1 = 1205 mm
R 2 = R 1 + Sludge thickness
Felt
sludge
Displacement
R 1
R 2
Belt Press 101
Felt
July 2018
Conventional Pressure Section
0
2
4
6
8
10
G W S1 S2 S3 S4 S5 S5 S6 S7 S8
PS
I
Rollers LS&P BFP Operational Training 101 35
36
24
18
14
12
10
10
Belt Press 101
July 2018
Optimum Pressure
LS&P BFP Operational Training 101 36
F F F F
Belt Press 101
July 2018
Excessive Pressure
LS&P BFP Operational Training 101 37
F F F F
Belt Press 101
July 2018
LS&P BFP Operational Training 101 38
Belt Press 101
July 2018
Performance Relationships
LS&P BFP Operational Training 101 39
Belt Press 101
July 2018
Feed Solids Vs. Cake
LS&P BFP Operational Training 101 40
15
17,5
20
22,5
25
27,5
30
32,5
35
1,00 2,00 3,00 4,00 5,00 6,00 7,00 8,00
Feed solids [%]
Cak
e d
ryn
es
s [
%]
ANAEROBIC DIGESTED SLUDGE
Belt Press 101
July 2018
Polymer Vs. Volatile Solids
LS&P BFP Operational Training 101 41
0
5
10
15
20
25
30
35
30,00 35,00 40,00 45,00 50,00 55,00 60,00 65,00 70,00
Po
lye
lectr
oly
te d
osin
g [lb
s/t
on
]
Volatile solids [% on TS]
Belt Press 101
July 2018
Volatile % Vs. Cake Solids
LS&P BFP Operational Training 101 42
15
17,5
20
22,5
25
27,5
30
32,5
35
30,00 35,00 40,00 45,00 50,00 55,00 60,00 65,00 70,00
Cake
dry
ne
ss [%
]
Volatile solids [% on TS]
Belt Press 101
July 2018
10.00
15.00
20.00
25.00
30.00
35.00
40.00
0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00
TSS %
Cake %
LS&P BFP Operational Training 101 43
Anaerobic %Cake Solids vs %TSS Belt Press 101
July 2018
High Solids Machines
LS&P BFP Operational Training 101 44
Municipal waste sludge (TSS = 4% ; VS= 65%)
0,00
2,00
4,00
6,00
8,00
10,00
12,00
14,00
16,00 gra
vity
wedge
1°
roll
2°
roll
3°
roll
4°
roll
5°
roll
6°
roll
7°
roll
8°
roll
9°
roll
10°
roll
11°
roll
12°
roll
13°
roll
14°
roll
15°
roll
Pressure zone
Su
rfa
ce
pre
ssu
re [p
si]
0,00
5,00
10,00
15,00
20,00
25,00
30,00
35,00
Dry
ne
ss [
%]
Torque
Dryness
Belt Pressure
Belt Press 101
July 2018
Modular configuration
LS&P BFP Operational Training 101 45
WR 5: working zones
WR5
WR7
WR 5: working zones
WR9
WR11
WR 5: working zones
WR 5: working zones
WR13
WR15
BELT WIDTH (M): 1.2 – 1.6 – 2.0 – 2.5 – 3.0
Belt Press 101
July 2018
• Wrap angles greater than 180 o Increase filtration area
o Decrease area pressure
LS&P BFP Operational Training 101 46
Wrap Angle vs. Area Pressure Belt Press 101
July 2018
• Throughput
• Cake solids
• Polymer dosage
• Capture
• Belt speed
• Pressure
LS&P BFP Operational Training 101 47
Performance Relationships Belt Press 101
July 2018
• Polymer dosage
• Detention time / belt speed
• High pressure filtration area
• Area pressure
• Cake stability
LS&P BFP Operational Training 101 48
Factors Affecting Cake Solids Belt Press 101
July 2018
Area Pressure Vs. Cake Solids
15%
17%
19%
21%
23%
25%
7 8 9 10 11
Solids
• Diminishing returns
• Reduced capture %
• Reduced belt life
LS&P BFP Operational Training 101 49
Belt Press 101
July 2018
Polymer Vs Cake Solids
• Dependent upon: o Operator attention
o Solids variance
o Bandwidth
0%
5%
10%
15%
20%
25%
30%
10 12 13 14 15 18
lbs / ton
Ca
ke
LS&P BFP Operational Training 101 50
Belt Press 101
July 2018
LS&P BFP Operational Training 101 51
Factors Affecting Polymer Dosage Belt Press 101
• Dynamic o Cascade effect
o Detention
o Mixing energy
o Media impact
• Static o Feed suspended solids
o Dissolved solids
o Volatile solids concentration
o Zeta potential
July 2018
Throughput Terminology
LS&P BFP Operational Training 101 52
Input
Filtrate Loss
Output
Belt Press 101
July 2018
• General method o Input
• The belt press equation o Output
• Mass balance
• Hydraulic loading vs. Solids loading
LS&P BFP Operational Training 101 53
Calculating Throughput Belt Press 101
July 2018
General Input Calculation
LS&P BFP Operational Training 101 54
• Q = flow rate (gpm)
• Ts = % concentration (TSS)
• Sg = specific gravity
Throughput = Q *Sg* Ts * 500.4
Belt Press 101
July 2018
The Belt Press Equation
55
• W = cake width (in)
• T = cake thickness (in)
• V = belt speed (fpm)
• Cs = cake solids (%)
• Sg = specific gravity
• K = 0.26
Throughput = W x T x V x Cs x Sg x K
Belt Press 101
LS&P BFP Operational Training 101 July 2018
• Capture o Polymer Dosage
o Fabric Weave / Permeability
o Proper Throughput
o Pressure
56
Factors Affecting Throughput & Capture % Belt Press 101
• Throughput o Belt speed
o Cake solids
o Effective belt width
o Cake thickness
o Specific gravity
July 2018 LS&P BFP Operational Training 101
• CAUTION WHEN CLEANING MACHINE!
• NEVER stand on side beams when operating
• NEVER place hands inside operating machine
• Verify Function of Tag Lines
• NEVER WORK ON ACTIVE MACHINE!
57
Safety Considerations Belt Press 101
July 2018 LS&P BFP Operational Training 101
Contact Langley Separation and Process
1405 Pecan Circle
Canyon Lake, Texas 78133
Main: 512-662-9917
Cell: 817-269-8388
Email: [email protected]
Web: www.langleyseparation.com
58
Questions or Comments Belt Press 101
July 2018 LS&P BFP Operational Training 101