Engineering Tips

A common cause of stripper instability is when operating pressure fluctuates, often due to poor control of the reflux condenser or fluctuations in the heat sink temperature. Therefore, flow changes should be made on a stepwise basis, and made as seldom as possible.

To avoid foaming in the stripping system, monitor conductivity of the incoming condensate and divert it away from the stripping system on high conductivity.

One technique to minimize turpentine accumulation in a stripper feed tank is to deliver condensate that may contain appreciable turpentine to the suction side of the stripper feed tank discharge pump, bypassing the feed tank entirely.

The stripper feed tank is operated as a surge tank, and turpentine in the condensate may separate and collect in a layer on the top of the condensate. The feed tank must be designed to prevent the turpentine accumulation, or include skimming or laundering provisions to remove the turpentine.

Some mills have found it advantageous to scrub the ionizable TRS from the CNCG before the gases are burned. This is typically done with a spray column using white liquor or caustic.

Consider installing hydrogen sulfide detectors in areas where leaks from the CNCG system may occur, especially inside buildings.