Transition in Pipe Size

[rjw57]

I am in the process of developing a mixing stage for a process I am working on. To minimize the overall length in the process flow direction, I have chosen to use mixing elements that are smaller in diameter than the upstream/downstream piping. I am trying to determine a way to minimize the effect of the flow stream reduction/expansion with the use of baffles (I really want, again, to minimize the overall length required for this unit operation). Has anyone ever seen any information related to the sizing/placement/design of baffles to help in distributing the flow at the stepped inlet and outlet of the mixing stage (6" to 3" to 6")? I cannot afford the length required by a "perfect" reducer geometry on both ends of the mixing stage.

rjw57

 

[MortenA]

Why should you bother with "perfect" transitions? You want to create turbulence (for mixing) dont you?

Best regards

Morten

 

[rjw57]

Morten

The mixers do their own job of crerating turbulence (actually, they create shear to be technical about it). I have upstream and downstream processes that rely on the fact that the flowstream occupy the better portion of the 6" tube. Without some form of transition, I would expect the flow on the up/down stream sides to tend towards channeling down the middle, approximating the 3" mixer diameter. Thank you for your reply.

rjw57