Sensonics Ltd. - PRODUCT NEWS

VIBRATION MONITORING PACKAGE IS IDEAL SOLUTION FOR COOLING TOWER FANS Effective monitoring of critical infrastructure is an essential requirement across the power generation, Oil, Gas and Petrochem industries where smooth running and trouble-free system operation is vital, especially in today's highly competitive and energy cost-conscious environment. Condition monitoring specialist SENSONICS are experts in developing highly effective monitoring systems based on over 50 years of experience, including vibration monitoring products. A good example of this is the recent completion of a cooling tower monitoring project at a major Petrochemicals plant. The Project Engineer at the site confirmed they were looking for a suitable system to monitor and protect cooling tower fans to prevent issues in case of failure of the fan blades. The requirement would be for individual systems to monitor each of the twenty motor / gearbox driven fans which were located between the motors and fans around the base of the cooling tower. Confirming the specific requirements of the application, the Project Engineer commented, "The fan speed is 131RPM / 2.18Hz and what we want is to have a single transducer mounted on the gearbox (each fan is mounted on the gearbox output shaft) and the issue we want to address is the potential failure of the fan blades. When this has happened, the vibration has been so severe it damaged the concrete platform that the fan assembly is mounted on, as well as damaging adjacent fans from the fan projectiles". Also, it was confirmed that, "The atmosphere where the fan is mounted is very wet and windy as the fans pull moist air out of the cooling tower packing and blows it across the gearbox and motor." Confirmation of these specific issues and challenges initially suggested the need to install a suitably ranged 4-20mA vibration transducer and then feed this to a closely located unit that has the start / stop buttons for the fans, enabling the tripping of a fan if the vibration is too high. There was also a need to feed the overall vibration levels to the main plant DCS system. Due to the specific requirements of this application the frequency of response of the transducers would need to be lower than below 2Hz and there was no requirement for any local display or further diagnostics. A simple system which would reliably trip the fan out if it were failing and additionally to give an indication on DCS for the overall vibration level. Conclusion Once the specific requirements of this vibration monitoring application were confirmed, Sensonics were able to suggest and supply a combination of their DN26 G3 dual channel protection system along with their VEL/GLF low frequency (slow speed) velocity transducers. Established in the condition monitoring market for many years Sensonics has supplied thousands of these compact and innovative, din rail mountable DN26 G3 dual channel vibration monitors which have delivered reliable and cost-effective vibration monitoring across a wide range of installations. This high performance fully programmable signal conditioning unit is capable of monitoring 2 channels of absolute vibration, shaft vibration or shaft position, while a third channel option is available for measuring speed or for use a phase reference. To complete the solution for this application is Sensonics VEL/GLF, a low frequency velocity transducer (slow speed) option proved to be ideally suited to the large fans which were operating at a minimum RPM. This electro dynamic sensor provides a superior performance compared to piezo-electric devices by combining high measurement sensitivity with a frequency response down to 0.5 Hz. This level of sensitivity, along with excellent noise performance, provides the necessary dynamic range required for detailed analysis of gearbox vibration, so is ideal for measuring velocity vibration on equipment with speeds down to 30 RPM. Furthermore, the VEL/GLF has advantages over traditional piezoelectric based velocity vibration sensors which are susceptible to many forms of interference in low frequency applications that can result in spurious readings and alarms. As a result of its robust design, the VEL/GLF offers high noise immunity due to the low impedance electro dynamic nature of the sensor assembly. In addition to the filtering of high frequency events and since no electronic integration is required, means the design of the sensor is immune to the saturation problems that impair the reliability of other piezoelectric devices. More Information >> For further information, please contact:- Sensonics Ltd. Northbridge Road, Berkhamsted HP4 1EF.UK Tel: +44(0) 1442 876833 Fax: +44(0) 1442 876477 Email: sales@sensonics.co.uk Website: www.sensonics.co.uk September 2025 Home - Search - Suppliers - Links - New Products - Catalogues - Magazines Problem Page - Applications - How they work - Tech Tips - Training - Events