Sometimes you can save a lot of money with a simple shift in instrumentation. A food processing company in Latin America discovered this when they confronted an ongoing problem with product waste in their corn tortilla processing line. pH sensors installed in the chemical dosing would sometimes break, creating potential contamination of not just the chemicals used in processing, but also the corn paste itself. Measuring the pH continuously was essential to assure the quality and shelf life of the product, but the breakage was slowing production and generating a large amount of product scrap. The company needed to make a simple but significant change to a non-glass pH sensor.
The company implemented a pilot test with a Rosemount TF396 which eliminates completely the glass portion of the sensor and replaces it with an ion-selective field effect transistor (ISFET) pH electrode that provides a stable pH measurement. Its rate of response can be ten times faster than glass electrodes, enabling better process control. Its short response time and increased stability at low temperatures make it suitable for use in cold processes like brine or water for cooling. Aging effects caused by temperature fluctuations or large changes of process pH are greatly reduced, providing longer intervals between calibration and maintenance of the sensor. The sensor's non-glass design can be used in many applications that restrict or prohibit pH glass electrodes due to the risk of broken glass getting into the process and this clearly met the company’s primary objective. In addition, the TF396 interfaced seamlessly with the Rosemount 1056 transmitter, which the company already employed.
Switching to the non-glass sensor created certainty that glass pieces will never contaminate the product. The online monitoring allowed the company additional savings by optimizing the usage of the chemical lab and its personnel. The successful implementation of the pilot program supported the company’s decision to replicate the same solution in their other seven parallel production lines. Annual savings of up to $17K USD are obtained per production line, which means ~$100K USD in total savings. An impressive return on a simple decision.
Learn more about the Rosemount TF396 here.
Posted by Deanna Johnson, Rosemount Measurement & Analytical Global Marcom Manager, Emerson Automation Solutions