Desupernation & corrosion in supernated steam lines

[CTSSA]

Water treated with sulphide and a polymer based boiler treatment chemical were drwan into a desuperheater at a sugar mill. (The water used in the process is of condensate quality). Corrosion has been blamed on the break-down of sulphite to an acidic form. The pattern of corrosion however appears as directionally aligned erosion resulting from water droplet implosion from water injection. All comments or similar experience would be gratefully accepted.

 

[dberner]

If it is erosion downstream of the water inject point, I would think the method of injecting water is not atomizing the spray water correctly. Often an inner wear liner is required downstream of the injection nozzle to protect piping against thermal shock and erosion.