BW PERUNDING SDN. BHD. COMPANY NO. 27875 P
CALCULATION SHEET
JOB: TAIPING HEADWORK CONTRACT NO.: MIG
PART OF WORK: Filter backwash Air scour
GROUP: M&E ASSISTANT: WNWA CHECKED BY: WNWA
DATE: 1/12/2009 FILE: 'file:///tt/file_convert/55cf91bc550346f57b903078/document.xlsx'#$WNWA
To determine the air blower size for back washing of the filter.
No of filter to be backwashed at one time = 1 no
Rate of air scour = 50 m3/m2/hr (Min) (Separate Air Water Wash System)60 m3/m2/hr (Max)
Air Scour Pressure= 0.35 bar = 3.5 m
Filter Length = 5.5 mFilter Width = 7.3 mFilter area = 40.15 m2
Therefore for MAX rate,the air required 2409 m3/hrAdd 10% safety factor = 2649.9 m3/hr
= 736.0833 l/s = 1558.5 cfm = 44.17 m3/min
Therefore for MIN rate,the air required 2007.5 m3/hrAdd 10% safety factor = 2208.25 m3/hr
= 613.4028 l/s = 1298.7 cfm = 36.80 m3/min
Air blower level = 117.15 mHighest air blower pipes = 125.6 mTotal static = 8.45 m
= 0.828431 bar
Pressure required min with 20% for losses and static loss = 1.414118 bar = 14.4 meter head = 20.5047 psi
Air Blower Selected: 2649.9 m3/hr @ 14.4 meter head
CALCULATION SHEET
JOB: Taiping Headwork Air Blower Pressure Calculation CONTRACT NO.:
PART OF WORK: Air Blower Calculations
GROUP: ASSISTANT: CHECKED BY:
DATE: 19/Apr/23 FILE: 'file:///tt/file_convert/55cf91bc550346f57b903078/document.xlsx'#$Air Blower Sizing
1.0 To determine the Air Blower Capacity:
* No. of filter to be backwashed at the same time = 1 No.
(Separate Air Water Wash System)
* Rate of air scour = 50 (Min)
60 (Max)
(Refer to the MWA's guideline)* Air Scour Pressure = 0.35 bar
= 3.5 m
* Filter area:Filter Length = 5.5 mFilter Width = 7.3 m
Filter Area = 40.15
* For maximum rate,the air required = 2409.00
Add 10% safety factor = 2649.9
= 736.0833 l/s
For minimum rate,the air required = 2007.50
Add 10% safety factor = 2208.25
= 613.4028 l/s
.: Therefore, the capacity of air blower = 2649.9
2.0 Air Blower Pressure Calculation:
* At ambient suction conditionSuction Pressure = 32
= 305.15 °KSuction Pressure = 1013.25 milibar abs
Blower Capacity = 2649.9
Ambient Air Density = 1.160 (How do you get this?)
Ambient Air Kinematic Viscosity = 0.00
BW PERUNDING SDN. BHD.(COMPANY NO. 27875 P)
m3/m2/hr
m3/m2/hr
m2
m3/hr
m3/hr
m3/hr
m3/hr
m3/hr
°C
m3/hr
kg/m3
m2/s
* At operating conditionDischarge Pressure = 71
= 344.15 °KAssume Discharge Pressure = 1450.00 milibar abs
Discharge Flow Rate = 1930.48
Discharge Air Density = 1.472 (How do you get this?)
Discharge Air Kinematic Viscosity = 0.00
* Static condition(Refer to the drawings)
Also, = Volume ratio
where - Suction flow
- Motive water flow
Hence, = 0
= #REF! = ### l/s
.: = #REF! = ### l/s
Let = 1.0 m/s
= #REF! mm say 200 mm
No of hoppers per bay, n = 3
and = +
.: = #REF! = ### l/s
Let = 1.0 m/s
= #REF! mm say 150 mm (ID)
Area of pipe = 0.017671
= #REF! m/s
°C
m3/hr
kg/m3
m2/s
Rw Qs / Q1
Qs
Q1
Qs Q1
Qs m3/min
Q1 m3/min
V1
f1
Q2 Q1 / n Qs
Q2 m3/min
V2
f2
m2
V2
= m/sat nozzle = 0.0 m/s
= #REF! mm
CHECK:1 N/mm2 = 145 psi
1 psi = 0.006897 N/mm210m head = 0.09807 N/mm2
1 psi = 0.703227 m head1 m of head = 1.422015 psi
3.0 Ejector Sizing
To calculate the duty of the sand ejector pumpset,Discharge pipe diameter = 100.00 mm
Lower end level of discharge channel = -1 m ELTop level of discharge pipe = 7.5 m EL
Discharge static head = 8.5 m = 12.09 psi
Assume discharge back pressure of = 10.0 m
From the Performance Curve, at discharge back pressure of 10.0 m, the followingdata are obtained.
Motive water flow rate = 39.0
Total agitation flow rate = 11.0
Suction flow rate = 17.0Motive water pressure = 44.0 m
Hence,
Motive water flow per eductor = 50.0Nos. of eductor = 2
Motive water flow for all eductors = 100.0
Eductor discharge flow rate = 56.0
4.0 Motive Water Pipe Loss
William-Hazen's Formula: =
Flow Rate Size Velocity Length Hazen K QtyQ D L William
(m) (m/s) (m) C
Motive water velocity VN (2g (H1-Hs))0.5
.: Nozzle diameter
m3/hr
m3/hr
m3/hr
m3/hr
m3/hr
m3/hr
Hf 10.666 x C (-1.85) x D (-4.87) x Q (1.85) x L
(m3/s)
1 Motive Water Pipe Loss
Suction Pipe:
a) Pipe Loss 0.028 0.2 0.89 8 90 0
Flow Rate Size Velocity Length Hazen K QtyQ D L William
(m) (m/s) (m) C
Fitting Loss:a) 90 deg bend 0.028 0.2 0.89 90 1 3 0b)c)
4.0 Motive Water PumpProvide 2 No. pumps (1 duty / 1 standby)
Motive Water Pump capacity required = #REF! l/sAllow for 5% fitting losses = #REF! l/s
Let Motive Water Pump capacity = 25.10 l/s = 90.36
Inlet pressure = 0.00 psi = 0.0 mLet Pump Head = 61.5 m
Check pipeworksLength of mains = 30 m
Allow for 5% fitting losses = 31.5 mFlow rate in l/sec = 25.10 l/sec
= 0.0251Pipe diameter = 200 mm f.i.d= 204 mm
Pipeline velocity = 0.77 m/secHazen William C value = 110
Head loss = 0.14 mTotal back pressure = 8.64 m = 12.28451 psi
FAIL!
(m3/s)
m3/hr
Flow rate in m3/sec m3/sec