The present disclosure describes a system for predicting explosions in a dissolving tank. The system includes acoustic emission sensors placed in or around the dissolving tank. By filtering the recorded frequencies to the range which is most sensitive for desired explosions fingerprints, it is possible to predict a smelt influx before the smelt influx occurs as well as program response actions to prevent compromising explosions.

The present disclosure describes a recovery boiler startup burner assembly that can mitigate the harmful effects of smelt fouling, airflow interference, and operator exposure to hot air from the furnace and win box through use of an extractable startup burner and an isolation chamber engaged to a windbox. The present disclosure also describes a method for safely extracting a startup burner from an active recovery boiler as has method for inserting an extractable startup burner into a recovery boiler during operation.

A recovery boiler plant of a chemical pulp mill including: a boiler including a lower region with an outlet to discharge smelt; a dissolving tank proximate to the outlet and configured to receive smelt; a smelt spout coupled to the outlet and including a chute extending from the outlet to a position at or over an inlet to the dissolving tank; and a shielding room including walls, a ceiling and a floor, wherein one of the walls includes a wall of the boiler, and the shielding room encloses a volume adjacent the boiler and above the dissolving tank, wherein the enclosed volume includes and the smelt spout and a working area in front of the smelt spout.