Cost Savings Thanks to Clamp-On Technology
Retrofitting a Katronic flow meter saves water utilities from costly construction projects and water supply shortages.
Noninvasive flow measurement for chlorine dosing
Non-invasive ultrasonic flow measurement has already proven itself in a wide range of applications worldwide. Fast, reliable, and precise, ultrasonic flow meters provide measurement data from the outside using “non-invasive” measurement, eliminating the need to open pipes or interrupt flow processes. This helps avoid plant downtime, production losses, and costly installation work.
A Katronic flow meter was recently installed at a water treatment plant operated by a major British water utility, which treats water drawn from two reservoirs and supplies more than 200,000 residents.
One of the main tasks in water treatment is disinfecting the water, which is accomplished at the plant by adding chlorine. The water flows through the 830 mm (DN) pipeline at an average flow rate of 640 liters per second (45–46 Ml/day). Absolutely precise dosing of the chlorine is of critical importance in this process. Originally, measurements were taken using an electromagnetic in-line flow meter; however, this proved to be unreliable and prone to leaks. Consequently, they needed a replacement measuring device that could provide reliable, accurate, and repeatable measurements and could also be installed with minimal disruption to the process.
The only access to the pipeline was via an inspection hatch leading into a relatively small pit. Installing a comparatively large electromagnetic flowmeter would have required extensive and expensive construction work that would have interrupted the process. This, in turn, would have necessitated finding an alternative water supply solution for the local population during the construction period.
A stationary flow measurement system from Katronic consists of a compact, wall-mounted unit for signal analysis and communication, as well as a robust pair of transducers that are clamped onto the pipeline. It took only a matter of minutes down in the pit to clamp the sensors onto the pipe and connect them to the remotely mounted KATflow 150 flow meter. A key advantage of Katronic’s measurement equipment is the quick and straightforward installation and setup of the system. Within a few minutes, a reliable 4–20 mA signal was delivered, proportional to the flow rate required by the chlorine dosing system.
As long as the pipe is fully filled, the system is largely independent of the liquid being measured. The time-of-flight difference method underlying the measurement system compares the “travel time” of a signal propagating in the direction of flow with the time of the signal sent upstream to derive the flow rate from the resulting difference.
