Friction Losses Claculation

[pivot]

I am dealing with a pumping system for the transportation of 30 m3/day.There is another stream with 1 % suspended solids .That stream is 150 m3/day.Total is 180m3/day
MY enquiry is
1-On what baiss I will calculate head losses ie taking clean water into account or sewerage water...
2-the fluid has to be transported to 1.2 km
3-There is no height involved during transportation
like the pipe will be at the ground level through out
so on what basis I will calculate friction losses
I am thinking to use a 4 inch poly pipe
Thanks

 

[BigInch]

I don't think < 1% solids is enough to worry about. You can use almost any head loss prediction equation you like, such as Churchill, Colebrook, or Darcy.

Set a low limit to the velocity of 1 m/s to keep the water moving fast enough so that solids are not allowed to settle at any low spots in the pipeline.

BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[Artisi]

Is the 180m3/day a continuous flow over the 24 hrs (ie, approx 2 l/sec) or is it intermittent to total 180m3 over 24hours.

The way the system is to operate will govern the pipe line diameter to use.

Phitsanulok
Thailand

 

[BigInch]

pivot, Since its a flat line, you do know you must have a pressure source at the beginning of the line to move this water (ie. pumped or some head pressure coming from somewhere), otherwise the line CANNOT be flat, it must be sloped ..... right? ..... RIGHT?


BigInch-born in the trenches.

http://virtualpipeline.spaces.msn.com

 

[jonelv]

pivot

The maximum flow rate is important to understand. As Artesi says, is the flow continuous throughout the day? Re the friction, for 1% sewage you can assume Newtonian flow. If you use Darcy to calculate then you can factor in the slightly different density / viscosity into the Reynolds number calculation but you will find it won't be significantly different a result to a clean water calculation.

4" poly pipe would seem appropriate - you wouldn't want to go smaller than this for a sewage rising main but if the flow is continuous you will have a low velocity. In that case you should look at a a daily flush of the pipe (stop the pumps, let the flow build-up in the pumping station and then run to give say a 1.2m/s pipe velocity.

Regards