Resolution of Evaporator Scaling Extends Uptime Nearly Two-Fold

Application of SC100 Successfully Arrests Scaling of Liquor Evaporator Surfaces

The Problem

A paper mill in the Southern US was experiencing decreased throughput of their black liquor evaporators. Shortly after cleaning the evaporators, a calcium carbonate buildup on heat exchange surfaces would occur. The steam valve would open to maintain target temperature, leading to scale formation. The scale increased over time until the evaporators had to be shut down for cleaning, well before a scheduled outage.

The Solution

ChemTreat analyzed the scale from the evaporator and recommended a program for crystal inhibition and dispersion. The proposal to use ChemTreat SC100 technology was accepted and a program targeting 20 ppm was initiated. The program was applied to the incoming weak liquor to target the effects where the problem was most pronounced.

The Results

Following implementation of the SC100 program, the customer immediately noticed an improvement in the function of the evaporators. According to the customer, the steam valve position trend did not show the sharp upward curve they had seen in the past. The interval between cleaning the evaporators increased from 4 weeks to the mill’s targeted 10 weeks. The evaporators were much cleaner and only required a cursory cleaning during the outage. The hard scale present in the past became less of an issue. SC100 was also applied to the green liquor line, helping limit the scale buildup in the system’s piping.

“That stuff is gold!” said the Mill Power and Recovery Manager.

Results are examples only. They are not guaranteed. Actual results may vary.