GeoEnvGuy (Geotechnical)27 Aug 20 17:08
I took the five minutes to run an iterative Hazen Williams flow calculation and based on the information provided it will take 89.75 minutes to get to 0.01 m of flow in the pipe. It will still have 6.23 m3 of water left in the pipe and flowing at roughly...
I think that a way would be to use an orifice equation until the last 70 meters, or until we have a height of 0,4 meters (the orifice diameter, 16 in). Then use Manning to the remain flow. And Add the two times
LittleInch, my answers:
Now it makes more much more sense. So this is reverse flow from the pipe high point back to the pumps? YES,full pipe from the 3299 mts and the 3270 pond
Yes the pipe will always be full from the pump to the high point.
I can only assume therefore that the 16" valve is...
Sorry LittleInch, i will show a diagram as soon as i can. When the pump stops, it leaves a volume in the line,i just assumed full pipe, from 3270 mts to 3299 mts at the top. The 16 inch valve is close to the pumps (at 3270 mts, where the blue line starts), so when I open the valve it returns the...
"the flow rate will vary continuously from the beginning to the end. it will gradually decrease as the water level drops and when the water level drops to the top of the 16 inch orifice, the flow regime will change to open channel flow which will be much slower."
Thanks you CVG, I'm trying to...
Thanks for your interest. I give my answers:
OK,
First things.
Do you know that the pipe is full when pumping? This makes a big difference to what is happening when the pump stops. I DON'T KNOW EXACTLY HOW TO MEASURE IT, I ASSUMED FULL PIPE.
So first you need to define and make sure of the...
Sorry, Five, if my post wasn´t clear. I need to calculate the time to drain the pipe after the pump shut down., (normally the pumps deliver the fluid from the lower level to another level)after the 3299 mts heigth. To empty the pipe I assume full flow from the top until the 16 in full open valve
Thanks you Five for your answers again. but if I consider by example,the first section
I would have:
H (height Difference)=1 m= L sin(slope).
Tank Radius: Big pipe diameter/2.
Total Tank Volume=1 mtrs*tank radius^2*pi()=0.65 m3.
but the total volume that i need to remove (assuming full...
Thanks you for your reply. the system delivers water to an open pond. I uploaded two pictures, one with an image of the system and another with the different heigts. When the pumps stops, i assume that leaves a full pipe from the end of the line (3299 meters above sea level) and delivers it to...
Dear Team,
I need to calculate how much it takes to drain a 36" full pipe, in three main sections with different slopes. We have a 16" full open valve to drain it.
I do the calculation dividing the sections in several parts, estimate the velocity and then the volume flow trough the orifice...