Duvel Moortgat (www.duvel.be) brewery in Puurs, Belgium recently employed Rosemount Analytical Model 3300HT PERpH-X pH sensors from Emerson Process Management (www.emersonprocess.com) to solve a production problem and improve efficiency. The previously installed pH sensors, monitoring the wort passing to the fermentation vessel, had become increasingly unreliable, at times only performing properly for a few days, with lifetime at best being a month or so. This was attributed to the temperature shocks inevitable in the process, which uses cleaning fluids at 85-90 C.

The Rosemount Analytical Model 3300HT pH sensors are designed to prolong sensor life in difficult hot processes, tolerating temperatures up to 145 C. The ACCUGLASS bulb used in the 3300HT improves the sensor speed of response, and makes the sensor tolerant to thermal shocks. The enhanced double junction reference electrode uses an outer gel-based reference that retains viscosity to resist the pumping action produced by temperature and pressure changes. To replace lost electrolyte, a Rosemount Analytical custom refill kit is available as an accessory. Using a gel filled syringe, the outer reference can be refilled, extending the life of the unit.

At the Duvel Moortgat brewery, initial trials with the 3300HT PERpH-X sensor showed it performed without any attention for over three months and then, by using the electrolyte gel refill kit, the sensor was returned to service within half an hour.

By introducing planned maintenance to the Rosemount 3300HT sensors on the site, Duvel Moortgat expects to save direct costs of over 1200 Euros a year, per wort monitoring point, with the improved reliability and lack of sensor failure alarms providing further benefits.