Maintenance and Inspection - Stack
September 8, 2003

Introduction

There is very little maintenance and inspection required for an acid plant stack.

Periodically, a thorough thickness survey should be done of the stack in the area of gas breach.

Stack Washing

The most common problem encountered with stacks is the emission of sulphate deposits.   During a prolonged stoppage the final inspection and cleaning of the stack base should be left as late as practically possible before starting up.

Some plant operators have found that cleaning of the stack can be achieved by introducing steam into the base during a plant stoppage.  The steam is left on for several hours and as it condenses it washes the sulphate off the walls.

Some plants wash their stacks on a regular basis every 6 months.   Washing the stack will tend to shorten the life of the stack.