20-04: Using an Ultrasound Measurement Technology to Monitor Real-Time Biofilm

Microbial (MB) growth management in cooling systems requires an integrated approach to control both suspended (planktonic) and sessile bacteria (biofilm) through proper chemical treatment and monitoring. Technologies are now moving toward in-situ monitoring of microbial growth in the cooling system. This paper reviews an advanced technology to monitor and, ultimately, to optimize the chemical usage for MB control. The core of the integrated MB control solution is based on a real-time monitoring device that employs both an ultrasonic thickness sensor and a thermal resistance sensor to detect biofilm growth. Evaluation was conducted under both laboratory and field conditions. Results indicate that not only the biofilm can be detected in the early stage, but also the instantaneous biofilm thickness measurement was responsive to different MB treatment programs. Case studies demonstrating successful MB growth management with the application of the technology in power, refinery, and chemical production industries will be discussed.