Surface acoustic wave: flow measurement and prevention of biofilm in water for injection loops
Flow control specialist Bürkert has developed a flowmeter that uses Surface Acoustic Wave (SAW) technology that also helps to prevent the formation of biofilms in Water for Injection (WFI) loops.
Designed for the pharmaceutical sector, Bürkert’s Type 8098 FLOWave flowmeter achieves high precision flow measurement by using contactless technology that also minimises the risk of contamination caused by poor flow characteristics.
The flow meter generates surface acoustic waves (SAW) that travel through the fluid. Calculating the time differences of the waves proportional to the flow, FLOWave can measure real time volume flow rate, cumulative volume, and flow velocity, as well as temperature, and all measurements are achieved irrespective of fluid conductivity or entrained bubbles.
The technology optimises precision measurement, which is essential to closely monitor flow velocity and temperature in WFI systems to prevent the formation of biofilms. FLOWave achieves the required performance with accuracy as close as 0.4% of the measurement, repeatable to just 0.2% deviation. This ensures that a minimum flow rate and sufficient turbulence can be maintained at all times, avoiding biofilm development.
Precision flow management also maximises pump efficiency by preventing unnecessarily high pump speeds that would require greater energy consumption and increased pump wear.
FLOWave’s contactless flow measurement technology is also highly reliable and maintains repeatable accuracy as it doesn’t rely on sensors that depend on media contact and can degrade over time. As SAW technology is less susceptible to faults, minimising maintenance requirements, FLOWave also requires less calibration compared to other sensor technologies.
The contactless design also removes the potential of contamination through bacteria accumulation that can occur on sensors positioned within the flow. FLOWave relies on a straight-through measuring tube that also removes any dead zones, which can lead to the accumulation of particles and microorganisms. To prevent corrosion, the flowmeter is constructed from 316L stainless steel and the design is also CIP/SIP compatible.
The compact flowmeter, which is light enough for a single engineer to install without lifting apparatus, also simplifies installation and maintenance. FLOWave is also configured for all modern digital communication protocols, simplifying integration with existing infrastructure.
Image 1: The precision and reliability of Bürkert’s FLOWave makes it ideal for WFI sub loop batching systems
