Issues with metal rotor flowmeters, seeking advice
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This post was last edited by guowei331 on 2010-9-25 at 10:57. Experts, I need to measure the flow rate of nitrogen here; the operating pressure varies between 600 KPA and 450 KPA, with steady fluctuations. Can a rotameter provide accurate measurements? ? What I need is the flow rate under standard conditions. If this doesn’t work, are there any other options that work well? ? Don’t choose the one of poor quality that’s expensive; can a board with no gas and one that adjusts pressure be used? Is that also not allowed? Seeking high-score advice
Can temperature and pressure compensation be done? It’s not difficult. A thermal mass flow meter is recommended.
Those with rotating vortices can be used; they are widely employed these days, and they come with temperature and pressure compensation
Vortex street, orifice plate, or turbine types are all acceptable – include pressure compensation!
Use a vortex street sensor, and add temperature and pressure compensation.
The ROSEMOUNT 8800 vortex flowmeter can be used to measure nitrogen with high stability; our factory is using it.
It can also be done using a rotameter; some rotameters are capable of measuring flow rates up to 6.3 MP.
Reply to 2# backhamm1982: If the density of our working medium increases and the temperature rises, will the value measured by the orifice plate be higher or lower than the actual value? I have a question: our flow rate lacks temperature and pressure compensation, and the composition also varies greatly?
As the density increases, the measured value becomes smaller than the actual value; compensation using temperature and pressure can address this
Rotary flowmeters do not have high accuracy; in my opinion, orifice plates are a good option, but it is necessary to calculate to determine whether they are suitable. Turbine or ultrasonic flowmeters can also be considered
To obtain the flow rate value under standard conditions, gas-flow measuring devices such as vortex flow meters, rotameters, and orifice plate flow meters must be compensated for temperature and pressure. The SHQL series of thermal gas mass flow meters introduced by Shanghai Hongke Automation Instrument Co., Ltd. feature the following advantages: ﹡ These gas flow meters require no temperature or pressure compensation; they can directly measure the volumetric and mass flow rates of gases under standard conditions. ﹡ They have an extremely low minimum flow measurement threshold, allowing measurement to start almost from zero, which is unmatched by other types of gas flow meters. ﹡ They offer high precision and fast response times, with a range ratio of up to 100:1, making them particularly suitable for metering purposes. ﹡ There is virtually no pressure loss in these flow meters, making them ideal for measuring gases with large diameters and low flow rates. ﹡ The sensors inside these flow meters have no moving parts; they are enclosed in sturdy 316L stainless steel or tantalum materials, which prevent contamination and sticking, allowing them to measure highly corrosive gases such as chlorine and phosgene. ﹡ These flow meters come in integrated or separate configurations, in either pipeline-style or insert-style forms, with a simple design that requires minimal installation and maintenance. ﹡ They provide on-site display of instantaneous and cumulative flow rates, signal output, as well as upper/lower limit alarms. ﹡ It is not necessary to open the cover of the meter to reset the cumulative flow value, which better meets explosion-proof requirements. ﹡ A flow straightening device can be used with these flow meters, significantly reducing the requirements for straight pipe sections before and after the meter. ﹡ A non-disruption installation device is also available, enabling removal and replacement while the pipeline flow continues unabated