mou
Civil/Environmental
- Apr 21, 2003
- 13
Hi all,
We've got a sewer pumping station where the high point is at the station itself and then it pumps downhill with several intermediate high points, then goes under a creek to the recieving sewer on the other side. Air Valves will be placed at hight points. There will be large amounts of air when the pumps are off. There is not enough volume in the wet well for the force main to ever pump full. Not a good design I know !!! My question is: How would you calculate the velocity in the main when the pump starts to account for the air in the main. I understand that 'normal' hydraulics/models do not apply in this instance. We need to work out the velocity to ensure self cleansing in the main. Any good web sites that show how to do this or can someone please advise.
Any other comments in regards the above would be most welcome.
Cheers
We've got a sewer pumping station where the high point is at the station itself and then it pumps downhill with several intermediate high points, then goes under a creek to the recieving sewer on the other side. Air Valves will be placed at hight points. There will be large amounts of air when the pumps are off. There is not enough volume in the wet well for the force main to ever pump full. Not a good design I know !!! My question is: How would you calculate the velocity in the main when the pump starts to account for the air in the main. I understand that 'normal' hydraulics/models do not apply in this instance. We need to work out the velocity to ensure self cleansing in the main. Any good web sites that show how to do this or can someone please advise.
Any other comments in regards the above would be most welcome.
Cheers