Ventilating Outlet of Flyash Mixer

[jives]

On our site we have a pug-mill type mixer which is used to mix fine, dry fly-ash from coal-fired boilers with water.

The flyash and water is mixed into a coarse paste in the pug-mill and then dumps from the pug-mill into a haul-truck.

The pug-mill is supposed to be "dustless" in that no dust should come out of the bottom outlet of the pug-mill.

However, we do get a fair amount of fine dust leaving the pug-mill outlet and blowing away in the breeze.

I have an old baghouse and fan, I am wondering if I can set up a sort of collection hood on the square outlet of the pug-mill to collect the dust in my old baghouse / fan ?

Several consultants have said we should ventilate the feed-end of the pugmill, but I have my doubts that this will work, especially since dust will be driven out of the pugmill outlet by the mixer blades.

Anyone have any suggestions ?

Jonathan Ives
Project Engineer
Transalta, Alberta Thermal Plants
Duffield, Alberta

 

[SAK9]

Fundemental to any dust extraction system is the capture velocity at the point of dust genertaion.You have to do a velocity profile for the hood arrangement and see whether it would have sufficient capture velocity at the outlet