As the largest industrial user of process water, pulp and paper mills are often located next to natural water sources. Bar screens are placed in intake channels or wet wells to remove debris that could damage mill equipment. When debris has accumulated, screen cleaning is accomplished with an automated rake typically actuated by a level control mounted in an upstream channel.
Water levels of intake channels and plant wells require monitoring. Though normally a routine application, freezing weather can cause complications for level controls, especially those that actuate screen cleaning. A level control operating in frigid, outdoor conditions must be accurate and reliable despite icing conditions.