Related calculations for flow rate, volume flow, pipe diameter, pressure difference, etc
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I would like to ask for advice; I’m a beginner. I am purging a pipe with a diameter of 1.5 meters using nitrogen, requiring an inlet and outlet flow velocity of 0.5 m/s. The diameter of the nitrogen source pipe for industrial nitrogen is only 150 cm. The nitrogen pressure is 0.8 MPA. I want to know how to calculate the pressure drop when a 150 nitrogen pipeline is connected to a 1.5-meter pipe. How can I ensure the flow rate of my replacement? Could some expert please provide a detailed explanation? It’s not necessary to give the final answer, but it would be great if the calculation process and the equations used could be explained. Thank you
Refer to \"Principles of Chemical Engineering\" to perform the calculation.
Bro, just tell me the calculation process! Your explanation really puts me in a difficult position! I’ve never studied principles of chemical engineering!
Can the Bernoulli equation be calculated? How is the Reynolds number determined? It feels like super-turbulence! As a further clarification, the diameter of the nitrogen pipe is 150 mm, not cm. Otherwise, it will be as thick as the pipeline to be replaced! Sorry, I typed it wrong!
Your nitrogen pressure is 0.8 MPa, so there’s no need to worry about flow rate to achieve satisfactory displacement: First, reduce the pressure in the pipeline to be displaced to 0.02 MPa, then fill it with nitrogen up to 0.6 MPa, followed by reducing the pressure back to 0.02 MPa. Repeat this process three times, and you’ll have achieved satisfactory results! You can give it a try; we never take flow rate into account when doing replacements.
The guy upstairs is talking about experience! So I ask you, why 0.6MPA? Are pipes with diameters of 150 mm and 150 cm both required to use a pressure of 0.6 MPa? Can it be the same? Moreover, my pipeline is newly built, so there is no process of pressure loss from the beginning. It should also be mentioned that, according to standard theoretical principles, the flow rate of the medium needs to be taken into account when performing displacement I need to prepare a relevant plan now; I have to come up with something convincing!
I also have a question for the person on floor 5! The pipe diameter changes from 150mm to 1.5m all at once – aren’t you considering the pressure drop?
If it is to be operated in situ, a tee should be added at the connection where the nitrogen enters the 1.5-meter tube; one branch of this tee is connected to a pressure gauge, while the other is used to inflate the tube. First, the end of the 1.5-meter tube should be closed off (using a valve or a blind flange), so that the pressure inside the tube can be monitored. The tube can then be purged by adjusting the pressure accordingly... :)