Peter Foith, CS Combustion Solutions, Austria, outlines the challenges faced when retrofitting an existing thermal stage of a sulfur recovery unit.
F
or the retrofit of a 700 tpd Claus plant with specific challenges, CS Combustion Solutions utilised its accumulated experience in designing and engineering combustion systems for sulfuric acid production, based on combustion of sulfur containing liquid and gaseous streams, spent acid regeneration units, and hazardous waste incineration, to supply new equipment. This included a low pressure drop swirl burner with staged combustion of Claus gas, a reactor utilising a Blasch VectorWallTM, and a new waste heat boiler with a focus on minimising the pressure drop to meet the clients’ requirements.
Initial situation Burner
The retrofit project started with the company analysing the existing equipment and engineering new equipment to overcome the various challenges. The original burner onsite was a multi-flame burner with low pressure drop on the Claus gas thermal stage, with undefined mixing of combustion air and Claus gas, which leads to low flame stability in low load cases as well as during start-up. The reason for the undefined mixing was found in the design of the original burner, as the HYDROCARBON 25
ENGINEERING
February 2022
