Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss...
-
Upload
bernard-brooks -
Category
Documents
-
view
216 -
download
0
Transcript of Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss...
![Page 1: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/1.jpg)
Week 1Unit ConversionsConservation of MassIdeal GasNewtonian Fluids, Reynolds No.Pressure Loss in Pipe Flow
Week 2Pressure Loss ExamplesFlow Measurement and ValvesPump Calcs and Sizing
![Page 2: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/2.jpg)
1000 gallons of wort is transferred to a kettle through a 15 m long, 4 cm diameter pipe with a roughness of 0.01 mm. The wort flows at a velocity of 1.2 m/s and assume that its physical properties are the same as those of water.
a) Determine the time required to transfer all of the wort to the boil kettle, in min.
b) Determine the Reynolds Number.
c) Determine the pressure drop in the pipe, assuming that the wort remains at 72C.
d) Would P change if the wort were at 20C?
![Page 3: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/3.jpg)
Head vs. P
Head/Pressure loss in Fittings and Valves Reference Sheet
g
Phead
![Page 4: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/4.jpg)
Consider the previous example. How would the pressure drop change if the pipework includes twelve 90 elbows and one fully open globe valve?
![Page 5: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/5.jpg)
Valves – Brewery Applications
Product Routing – Tight shutoff, material compatibility, CIP critical
Butterfly and mixproof
Service Routing – Tight shutoff and high temperature and pressure
Butterfly, Ball, Gate, Globe
Flow Control – Precise control of passage areaGlobe (and needle), Butterfly
Pressure Relief – Control a downstream pressure
![Page 6: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/6.jpg)
Valves – Globe Valve
Single Seat- Good general purpose- Good seal at shutoff
Double Seat- Higher flow rates- Poor shutoff (2 ports)
Three-way- Mixing or diverting- As disc adjusted, flow to one channel increased, flow to other decreased
![Page 7: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/7.jpg)
Valves – Butterfly Valve
Low Cost
“Food Grade”
Poor flow control
Can be automated
![Page 8: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/8.jpg)
Valves – Mix-proof Double Seat
Two separate sealing elements keeping the two fluids separated.
Keeps fluids from mixing
Immediate indication of failure
Automated, Sanitary apps
Easier and Cheaper than using many separate valves
![Page 9: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/9.jpg)
![Page 10: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/10.jpg)
Valves – Gate Valve
Little flow control, simple, reliable
![Page 11: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/11.jpg)
Valves – Ball Valve
Very little pressure loss, little flow control
![Page 12: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/12.jpg)
Bernoulli Equation
Notice how this works for static fluids.
€
P +1
2ρv 2 + ρgz = Constant
![Page 13: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/13.jpg)
Flow Measurement – Oriface Meter
Cd accounts for frictional loss, 0.65
Simple design, fabrication
High turbulence, significant uncertainty
2
1
2
2
1
2
AA
PACQ d
P1 P2
![Page 14: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/14.jpg)
Flow Meas. – Venturi Meter
Less frictional losses, Cd 0.95
Low pressure drop, but expensive
Higher accuracy than orifice plate
2
1
2
2
1
2
AA
PACQ d
P1P2
![Page 15: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/15.jpg)
Flow Meas. – Variable Area/Rotameter
Inexpensive, good flow rate indicator
Good for liquids or gases
No remote sensing, limited accuracy
WeightDragForces
mgvCdrag 2
2
10
vAV
![Page 16: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/16.jpg)
Flow Measurement - Pitot Tube
Direct velocity measurement (not flow rate)
Measure P with gauge, transducer, or manometer
P1
P2
1 2
2
2
21v
PP
v
![Page 17: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/17.jpg)
Flow Measurement – Weir
Open channel flow, height determines flow
Inexpensive, good flow rate indicator
Good for estimating flow to sewer
Can measure height using ultrasonic meter
![Page 18: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/18.jpg)
Flow Measurement – Thermal Mass
Measure gas or liquid temperature upstream and downstream of heater
Must know specific heat of fluid
Know power going to heater
Calculate flow rate
![Page 19: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/19.jpg)
Pumps
z = static headhf = head loss due to friction
Pump
fss
ss hρg
Pzh HeadSuction
Suction Delivery
fdd
dd hρg
Pzh HeadDelivery
fsfdsd
sdsd hhρg
PPzzhh Head Total
![Page 20: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/20.jpg)
PumpsDistanceForceWork
DistanceAreaArea
ForceWork
time
DistanceArea
Area
Force
time
WorkPower
Flowrate VolumeΔPPower
ghVPV Output Power
Efficiency Pump
OutputPower InputPower
![Page 21: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/21.jpg)
Pumps
Calculate the theoretical pump power required to raise 1000 m3 per day of water from 1 bar to 16 bar pressure.
If the pump efficiency is 55%, calculate the shaft power required.
If the electrical efficiency is 95%, calculate the electrical power required.
Denisity of Water = 1000 kg/m3
1 bar = 100 kPa
![Page 22: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/22.jpg)
Pumps
A pump, located at the outlet of tank A,must transfer 10 m3 of fluid into tank B in 20 minutes or less. The water level in tank A is 3 m above the pump, the piperoughness is 0.05 mm, and the pumpefficiency is 55%. The fluid density is 975 kg/m3 and the viscosity is 0.00045Pa.s. Determine the total head andpump input and output power.
Tank A
Tank B
8 m
15 m
4 m
Pipe Diameter, 50
mm
Fittings = 5 m
![Page 23: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/23.jpg)
Pumps
Need Available NPSH > Pump Required NPSH
Avoid Cavitation
z = static headhf = head loss due to friction
fs
v hP
ρg
Pz NPSH Available ps
s
![Page 24: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/24.jpg)
Pumps
A pump, located at the outlet of tank A,must transfer 10 m3 of fluid into tank B in 20 minutes or less. The water level in tank A is 3 m above the pump, the piperoughness is 0.05 mm, and the pumpefficiency is 55%. The fluid density is 975 kg/m3 and the viscosity is 0.00045Pa.s. The vapor pressure is 50 kPa andthe tank is at atmospheric pressure.Determine the available NPSH.
Tank A
Tank B
8 m
15 m
4 m
Pipe Diameter, 50
mm
Fittings = 5 m
![Page 25: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/25.jpg)
Pump Sizing
1. Volume Flow Rate (m3/hr or gpm)
2. Total Head, h (m or ft)
2a. P (bar, kPa, psi)
3. Power Output (kW or hp)
4. NPSH Required
hgP
![Page 26: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/26.jpg)
PumpsCentrifugal
Impeller spinning inside fluid
Kinetic energy to pressure
Flow controlled by Pdelivery
Positive Displacement
Flow independent of Pdelivery
Many configurations
![Page 27: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/27.jpg)
Centrifugal Pumps
Constantρgzρv2
1P 2
Impeller
SuctionVolute Casting
Delivery
![Page 28: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/28.jpg)
Centrifugal Pumps
Flow accelerated (forced by impeller)
Then, flow decelerated (pressure increases)
Low pressure at center “draws” in fluid
Pump should be full of liquid at all times
Flow controlled by delivery side valve
May operate against closed valve
Seal between rotating shaft and casing
![Page 29: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/29.jpg)
Centrifugal PumpsAdvantages
Simple construction, many materialsNo valves, can be cleaned in placeRelatively inexpensive, low maintenanceSteady delivery, versatileOperates at high speed (electric motor)Wide operating range (flow and head)
DisadvantagesMultiple stages needed for high pressuresPoor efficiency for high viscosity fluidsMust prime pump
![Page 30: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/30.jpg)
Centrifugal PumpsH-Q Chart
Head
(or P)
Volume Flow Rate
Increasing Impeller Diameter
A B C
![Page 31: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/31.jpg)
Centrifugal PumpsH-Q Chart
Head
(or P)
Volume Flow Rate
A B C
Increasing Efficiency
Required NPSH
![Page 32: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/32.jpg)
Centrifugal PumpsH-Q Chart
Head
(or P)
Volume Flow Rate
A B C
![Page 33: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/33.jpg)
Centrifugal PumpsH-Q Chart
Head
(or P)
Volume Flow Rate
Required Flow
CapacityActual Flow
Capacity
Required Power
![Page 34: Week 1 Unit Conversions Conservation of Mass Ideal Gas Newtonian Fluids, Reynolds No. Pressure Loss in Pipe Flow Week 2 Pressure Loss Examples Flow Measurement.](https://reader036.fdocuments.us/reader036/viewer/2022062516/56649e185503460f94b040e8/html5/thumbnails/34.jpg)
Pump Sizing Example
Requirements8 gpm100 feet of head
Choose the proper impellerDetermine the power consumed by the pumpDetermine the NPSH required