Selection of flow meters for large-diameter circulating water pipelines
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For the DN1800 circulating water pipeline, with a flow rate of around 10,000 m3/h, a pressure of 4 kilograms, and temperatures ranging from 20 to 30°C, it is necessary to install a flow meter. Due to cost constraints, the insert-type electromagnetic flow meters that were used previously were not very stable and could not provide accurate measurements. To resolve this issue completely, stability and accurate measurement are required. Which is better: an insert-type ultrasonic flowmeter or a pipe-type electromagnetic flowmeter? In addition, the convenience of maintenance and repair must also be taken into account. Since scale tends to form on the inner walls of circulating water pipes, and sludge adhering to the sensor electrodes can affect measurement accuracy, there are concerns that maintaining such pipes using electromagnetic devices might be troublesome. If electromagnetic flowmeters are used, which type of lining – Teflon or rubber – is less prone to sludge accumulation and scaling? Is the mud-type effect better? Attached are several photos showing the scaling on the equipment and pipes that use circulating water; please discuss together to determine what represents the best option.
A differential pressure flow meter is selected due to its high stability. You may want to learn about the American A+QMC balanced flow meter; for large pipe diameters, a two-piece with one intermediate piece design can be used, offering a range ratio of 10:1 and a high accuracy of 0.5. Low requirements are imposed on the straight pipe sections – 2D ahead and 2D behind is sufficient.
1. First of all, I have to complain about this circulating water system of yours – it’s suffering from scaling and corrosion. II. Depending on the operating conditions, a two-channel or three-channel wet ultrasonic flow meter can be considered. It is best to use flanged openings on the pipes, which facilitates regular inspection and maintenance.
The 4th floor answer is correct; using a differential pressure type flow meter in your case will also lead to severe clogging. How about trying a wedge-shaped flow meter instead? ? Simply put, it’s ultrasound – simple, effective, and easy to maintain.
Agree with what was said on floor 4: the ultrasonic version should be designed as a flange-type unit, or considering a model with flushing functionality. For the tubular electromagnetic type, it’s necessary to have electrodes equipped with scrapers or to allow for their removal
With such a large pipe diameter, a differential pressure type should be used; the energy loss resulting from pressure losses could afford several sets of meters in terms of cost per year
Is it not recommended to use electromagnetic flowmeters? When using ultrasound, it’s always rather unstable, and the signal quality often has problems
Ultrasonic waves – this circulating water doesn’t have a bypass filter for treatment
Stay away from the pump and where there is little vibration (ultrasonic sensors don’t work well due to the interference caused by vibrations); an insert-type vortex flow meter could be considered. The timing for regular cleaning should be determined based on the quality of the water. Differential pressure sensors are expensive, and they can also cause severe blockages in the pipes, so they are not recommended.