Inline Process Refractometer Products for Green Liquor - Electron Machine Corp.

The rugged and reliable MPR EScan is used to measure the green liquor dissolved density, or TTA, at two stages in the process: after the green liquor dissolving tank and after the green liquor clarifier. The in-line measurement, with the refractometer sensing head installed directly in the main process lines, allows real-time control of green liquor dilution to meet target TTA set-points. The measurement is also used to indicate (and prevent) excessive green liquor density and the resulting dangerous impending crystallization within the dissolving tank.

The difficult scaling associated with green liquor results in an optical coating on the refractometer sensing head. If this scaling can be controlled to allow an acceptable duration of on-line measurement, and then effectively removed when coating occurs, the accuracy of the refractometer can be fully utilized with minimal maintenance. The primary issue then becomes the maintenance required to keep the cleaning system operating effectively.

Reducing the variation of green liquor solids by automatically controlling weak-wash dilution with the MPR E-Scan™ refractometer results in a reduction in scaling. Scaling issues are further reduced when pressurized water, heated to the process temperature, is used to effectively clean the refractometer optical components. The compound result is beneficial for both control and maintenance.