Elliptical gear flow meter.
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“For an elliptical gear flow meter, the volume of the fluid discharged per rotation is 4 times the volume of a semi-cylinder; thus, the volumetric flow rate Q of the fluid can be calculated. This is something written on the Internet. I’m also lacking relevant information – no one explains where this factor of 4 comes from; I think it should be 2 times instead! !
An elliptical gear flow meter utilizes two axially symmetric elliptical gears that work together; as the fluid to be measured passes through the flow meter, it causes these two gears to rotate. Each gear has a semi-circular cavity that is filled with the medium as it passes through. With each rotation, the semi-circular cavity of each gear is filled twice (once on the upper side of the gear and once on the lower side), so each gear discharges twice the volume of its semi-circular cavity. Since there are two gears, the total volume will be four times the volume of each semi-circular cavity. This is why it is said online that one full rotation discharges an amount of medium equal to 4 times the volume of a semi-circle. .
If you look at these images, you can focus on either the upper or lower gear; in either case, it rotates almost exactly 180 degrees. From these four images, it can be seen that a total of 2 semi-circles are formed, so one full rotation results in 4 semi-circles being formed. Actually, you don’t need to worry about too many things. All you need to know is how much liquid is discharged with each rotation and pulse generated, as well as how many pulses the PLC receives; with this information, it’s possible to calculate the flow rate and cumulative amount of liquid.
There is nothing useful or useless; if you don’t understand, just ask
Got it, thanks for your patient explanation, {:1_90:}