Teflon & Kynar Lined Static Mixers0 pages

Komax Teflon Lined Mixer
Simplifies Acid Injection
for Power Plant
CASE STUDY 823

A major source of waste water in many power plants is the
waste stream that results from ion exchange used for
demineralizing the boiler feed water.
The alkaline regeneration waste stream produced by the ion
exchange process requires the addition of an acid to this
stream before discharge from the plant. Regulatory authorities
typically require the effluent to have a near neutral pH before
disposal in the sewer system.
A Utah based energy company uses concentrated sulfuric acid
(98%) to economically neutralize their demineralization waste
stream.
Previously an expensive neutralization tank with a propeller mixer
and a secondary “smoothing” tank with a propeller mixer was
needed to mix and dilute the viscous concentrated sulfuric acid
2
used for this neutralization process. These tanks covered 400 ft
of floor space and the mechanical mixers consumed 65,000 kw-hr
annually.
Maintenance was estimated at $25,000 annually, as the high solids
constantly fouled the pH probe, and the mechanical mixers required continual maintenance, and
the tanks required annual cleaning due to the sludge that would build up in these tanks.
The neutralization tanks were replaced with a 3” Teflon lined in-line static mixer with optional
injection port for direct injection of the sulfuric acid. The pH probe was placed downstream of the
mixer, providing immediate feedback to the sulfuric acid dosing pumps.
This in-line static mixer saves energy costs, maintenance labor, reduces space requirements, and
has achieved consistent control over the neutralization process.

(shown) Teflon Lined Static Mixer with Additive Injection Disk

823– 06/23/06 eca