The addition of small amounts of specialty chemicals and dyes in pulp and paper processing is an ongoing problem. With low flow measurement capability, chemicals that might have previously been added all at once to a batch can now be fed continuously at very low flow rates.
Low Liquid Flow
A manufacturer of paper products purchased a Rheotherm flow meter to measure the low flow of a hardening agent used in a two-component primer. Previously, the primer was premixed in a large tank at the start of the paper coating process. This worked well until there was an interruption in the process. With the hardener already added, the primer would set up. Once the primer hardened, it would have to be chipped out of the tank and a new batch made. This is a time consuming procedure and expensive problem.
With the unique low flow capability of the Rheotherm flow meter, the customer could revamp his process so the hardener is added continuously at a low flow rate, just before the primer is applied to the paper. If the process stops, the hardener flow can be stopped and no product is wasted. The typical flow rate is less than 150 ml/min.
Rheotherm advantage: accurate low flow measurement, high reliability
A large paper company called Intek after being fined by the EPA for creating foam in a local stream. Normally, their treated wastewater has a defoamer added before it is discharged into the local waterway. However, the first time an undetected failure of the defoamer pump occurred, they had a problem. The addition of a Rheotherm flow switch to this critical service has prevented additional occurrences and fines.
Rheotherm advantage: corrosion resistance, low flow sensitivity
Several large paper companies use Rheotherm flow meters to measure their low flow rates of various dyes. Dye flow rates ranging from less than 1 to several hundred cc/min are repeatably measured, and the flow sensors easily withstand solvent or water flushing.
Rheotherm advantage: low flow sensitivity, not damaged by over ranging