|Flow types||Single phase, slurry, multiphase, organic, reagents, tailings|
|Temperature range||0°C – 60°C|
|Typical accuracy||Better than 5%|
|Integration||CSV to cloud|
|Pipe material||Steel, HDPE, PVC, FRP|
|Pipe size||2″ – 100″|
* customised variants available
- Eddy currents are present in turbulent flow, moving close to the average velocity of the flow
- phase independent
- no calibration requirement
- eddy currents impart dynamic radial strain on the pipe wall
- optical fibre attached to the exterior of the pipe measures the convection of these pipe motions, allowing direct observation of flow speed and sound speed
- up to 10 individual stations per iDAS, with the same fibre
Non-intrusive flow metering: how it works
Silixa’s non intrusive flow metering system functions by measuring the speed at which turbulent flow vortices move through the pipe.
Previous work has shown that, in constrained, well-developed, fluid flow, the motion of local convective fluid disturbances can introduce dynamic pressure variations which in turn impart dynamic strain on to the boundary walls. In the case of flow within a pipe, this dynamic strain field can be observed using a hoop strain –sensitive sensor mounted on the outer wall of the pipe. Where an array of synchronized strain sensors is spaced with intervals less than the coherence distance for the flow, then the local convection of these vortical entities can be used to monitor the flow speed. It is in fact possible to use the DAS system to achieve such an array. By wrapping a continuous length of fibre helically around the exterior pipe, the DAS system can measure the dynamic radial strain exerted along a section of a pipe and measure the convection speeds of eddies. In addition, the speed of sound can be measured both through the wrapped section of the fibre and over the entire length of the cable installation.