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Line Sizing 3
- Thread starter chem55
- Start date
Montemayor
Chemical
Learn the theory and application of the Darcy-Weisbach equation by obtaining and studying Crane Technical Paper #410 and Cameron Hydraulic Data. Both can be obtained through the internet.
The above will familiarize you with the basic division existing between compressible and non-compressible flow. And this only applies to Newtonian fluids. For 2-phase flow, you've a lot of more studying and reading to do but I assume you are not going to go that far into the subject.
Work the various example problems illustrated in Crane's Tech Paper #410 and that should be enough to get you up and started on sizing simple hydraulic circuits.
The above will familiarize you with the basic division existing between compressible and non-compressible flow. And this only applies to Newtonian fluids. For 2-phase flow, you've a lot of more studying and reading to do but I assume you are not going to go that far into the subject.
Work the various example problems illustrated in Crane's Tech Paper #410 and that should be enough to get you up and started on sizing simple hydraulic circuits.
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3
- #3
brainstorming
Chemical
As a start do the following:
1- check the flow region either Turbulent or Laminar
Re= (de.*vel.* Dia / vis.)
Turbulent Re > 2000
Laminar Re < 2000
constants usually given Q, de. ,vis.
Guess Dia
vel. = Q/A where A= pi/4 Dia^2
2- A) use Fanning's equation for Re> 2000
delta P = (4*f)(L/Dia)(de.* vel.^2/2)*10^-5
B) use Hagen-Poisuille's eqaution for Re <2000:
delta p = (32)(vis.* vel.*L/Dia^2)10^-5
where L is pipe length (straight)
Note all units are in SI
3- Calculate delt P resulting from fittings i.e. elbows..etc using isometric drawing
4- Find the total pressure drop of the system that is
delt P of the straight length + delt P of the fittings
5- If the resulting pressure drop matches your system pressure drop requirement then, the guess Dia is the line Diameter
6- If step 5 is not correct try another Dia to satisfy your required pressure drop
7- Other criteria if not pressure drop is of a concern, i.e, there is no anchor point in the system, you might be limited with velocity requirements, if so, follow steps 1 to 4 and check the velocity result
I hope this would help you in understanding the piping hydraulic calculations since this is what the eng. offices are doing for designing a plant but via their own software for the whole plant with many integrated piping,
what you can do is to develop a spreadsheet with steps I mentioned and you will benefit a lot
Regards
1- check the flow region either Turbulent or Laminar
Re= (de.*vel.* Dia / vis.)
Turbulent Re > 2000
Laminar Re < 2000
constants usually given Q, de. ,vis.
Guess Dia
vel. = Q/A where A= pi/4 Dia^2
2- A) use Fanning's equation for Re> 2000
delta P = (4*f)(L/Dia)(de.* vel.^2/2)*10^-5
B) use Hagen-Poisuille's eqaution for Re <2000:
delta p = (32)(vis.* vel.*L/Dia^2)10^-5
where L is pipe length (straight)
Note all units are in SI
3- Calculate delt P resulting from fittings i.e. elbows..etc using isometric drawing
4- Find the total pressure drop of the system that is
delt P of the straight length + delt P of the fittings
5- If the resulting pressure drop matches your system pressure drop requirement then, the guess Dia is the line Diameter
6- If step 5 is not correct try another Dia to satisfy your required pressure drop
7- Other criteria if not pressure drop is of a concern, i.e, there is no anchor point in the system, you might be limited with velocity requirements, if so, follow steps 1 to 4 and check the velocity result
I hope this would help you in understanding the piping hydraulic calculations since this is what the eng. offices are doing for designing a plant but via their own software for the whole plant with many integrated piping,
what you can do is to develop a spreadsheet with steps I mentioned and you will benefit a lot
Regards
sailoday28
Mechanical
Try to keep Reynolds numbers out of ranges between 2000 to 3000. The friction factor in that flow regime is extremely hard to prerdict.
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