Processing Magazine

Switch ideal in separation tanks or other vessels with mixed density media

January 5, 2010
The switch performs monitoring, controlling and alarming of flow rates or levels of critical fluids such as foams, emulsion layers, liquids and slurries. Its rugged industrial design and housing provide superior reliability and long service life under the harshest plant environments in chemical refining, waste treatment and other industries, according to the manufacturer. The switch is a dual-function insertion-style instrument that offers either flow/temperature sensing or level/temperature sensing in a single device. Dual 6A relay outputs are standard and are assignable to flow, level or temperature. The switch relies on the specific heat transfer properties of the media to identify the interface of different products. With its unique thermal dispersion sensing capability, the switch monitors the interface of products with similar densities for highly reliable control in separation tanks and other vessels. The unit can identify the interface between any type of media including foam, emulsion layers, liquids and slurries. The dual switch point option allows one instrument to control two different product interfaces. Two or more switches are used to control product discharge and intake at specified points. The switch operates over a wide setpoint range in water from 0.01 to 0.5 FPS. Level/interface accuracy is ±0.25 inch, and measurement repeatability is ±0.125 inch. The switch withstands operating temperatures from -40 to 350°F, and an optional configuration is available for temperatures from -100 to 850°F.