Phosphoric Acid Plant Modernization
Ultrafertil, SA, Cubatão, Brazil

Ultrafertil's Dorr-Oliver phosphoric acid plant was restricted to 350 tpd P2O5 capacity by cooling limitations.  KEMWorks prepared a Basic Engineering Package for a Prayon Low Level Flash Cooler System.

The Flash Cooler was installed on top of the reactor in place of the existing Flash Cooler that was too small.  An axial flow pump circulates a large volume of slurry through the Flash Cooler with a very small temperature drop.  This minimizes excessive nucleation and the formation of small difficult-to-filter gypsum crystals.  Vapor from the Flash Cooler is partially condensed in a precondenser to provide hot water for filter cake washing before passing to the barometric condenser.

Project Highlights:

• Increase in capacity from 350 to 500 tpd P2O5 by installation of a Prayon Low Level Flash Cooler.
• Plant tie-ins made in a two-week turnaround.
• Steam for cake wash heating is eliminated by the use of a precondenser. 

The upgraded plant was started up in August 1999 and has achieved rates of over 500 tpd P2O5.