How about giving everyone a problem on chemical engineering principles?
Thread Content
The pipe diameter is D=4″, the fluid pressure at P1=0.4 MPa (upstream), and the pressure at the pipe outlet P2 can be considered as 0. The question is: what is the maximum flow rate Q that can pass through this pipe section, in m3/h? The effective length of the pipe is L=20m; since the medium is water, the friction coefficient can be ignored. Everyone is welcome to participate actively. This post was last edited by dyzdyz12345 on 2009-4-8 04:36.]
"The pipe diameter is D=4″, the fluid pressure at P1=0.4 MPa (upstream), and the pressure at the pipe outlet P2 can be considered as 0. The question is: what is the maximum flow rate Q that can pass through this pipe section, in m3/h? " Can it be calculated using the principles of chemical engineering? For a pipe length of 100 m, what is Q in m3/h? For a pipe length of 1 m, what is Q in m3/h? For a pipe length of 0.00001 m, what is Q in m3/h?
Pipe length: 20m, O(∩_∩)O Thank you. Please discuss in detail
To find the maximum flow, treat it under ideal conditions. Write the mechanical energy balance equation, using the centerline of the pipe as the reference horizontal plane. Since Z1=Z2 and We=0, the frictional resistance is 0; therefore, P1-P2=400 Pa. The continuity equation gives U2/U1=A1/A2=1. The diameter of the outlet pipe is smaller!
It is circulating water, and the friction coefficient can be ignored
The pipe diameter = 4″ or DN100; it’s already specified. Hehe, bro, your analysis is great – everything is clear now. Keep working hard; I’m looking forward to seeing a result. No points awarded for now, but they will be given later:P
Maximum theoretical possible flow rate: 979 m3/h
Without considering the friction factor, the flow rate is over 700 cubic meters. But why not take frictional losses into account?
a. C = 299792458 m/s = 17987547480 m/Hr. b. The cross-sectional area of a 4-inch pipe is 0.000506451 m^2; the volume flow rate is equal to a times b, which equals 9109804.214 m^3/Hr. 1. If friction is not taken into account, the object will keep moving at a constant speed…. 2. It is generally believed that the highest speed in the universe is the speed of light…. 3. Due to the thickness of the pipe walls in 4-inch pipes, tolerances can be ignored. Using 100mm as the base for calculation. 4. This is no longer a chemical engineering issue :lol :victory: Last edited by rezset on 2009-4-8 17:19.]
The answer above is correct; it falls within the realm of physics.
Will it really be this large? Its main pipeline is DN450; the normal flow rate is below 250 m3/h, while the design capacity is 550 m3/h – is that reasonable? ? ?
Going back upstairs, considering the friction factor, the flow rate is 100 cubic meters. ---------------------- Correction: there was an error in the original calculation of the pressure difference; it should be 120 cubic meters. This post was last edited by yu*nyang_01 on 2009-4-11 at 12:08.]
Up to 5 meters of vertical pipe, with the remaining over 10 meters being horizontal
With no resistance, the flow rate can be infinite, just like in superconductors.
The person upstairs is right; it should be infinite traffic.