Orifice pressure drop

Jan van Heerden - RSA
(not verified)
Posted in: , on 3. Sep. 2003 - 08:28

Hello everybody,

I am re-designing the pulverized fuel pipelines for one of our coal fired power stations. A coal mill serves 4 pipes and each pipe is connected to one burner. The variations of the solids flow to the 4 burners are quite large.

We want to balance the flow with orifice plates, but I cannot find a formula for 2-phase flow. I am also looking for a formula to calculate the pressure drop in 2-phase flow across a sudden reduction in the pipe.

Your help will be appreciated.

Thanks,

Jan

Re: Orifice Pressure Drop

Erstellt am 15. Sep. 2003 - 09:28

Dear Jan,

If the massflow after your splitter is unbalanced may have different reasons:

1.) unsufficient flow conditions in front of splitter

2.) wrong type of splitter (especially for coal feeding)

3.) unbalanced ductwork after splitter

If you can eliminate 1.) and/or 2.) at least 3.) remains. You have to adjust massflow into the 4 lines. Orifices in general cause instabilities, better is a additional pressure loss at the end of the line so that this pressure loss is the main loss in the system.

This can be done by adding nozzles.

If you want to get more informations, pictures etc. pls. send me an email :

schneider@enviro-engineering.de

or visit also our website: www.enviro-engineering.de

Best regards

Klaus Schneider