A floating disk is installed inside the product tank, and a single-flange level gauge is used for measurement
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For measuring liquid levels in the company’s tank areas, one method uses a single flange while another employs guided wave radar. In some tanks, there are metal floats sealed with rubber rings; as the liquid level rises, it pushes up against these floats. Will the gravity of the floating disc affect the measurement of the single-flange type? I remember in high school, during physics class, a half-full beaker was placed inside a larger beaker; the pressure at the bottom of that beaker was calculated using the pgh formula. I wonder if an object that remains floating on a medium and has its edges sealed with rubber rings would affect the measurements taken with a single-flange device. I think it shouldn’t, but I’m not sure if anyone has used this type of structure in their projects
This post was last edited by 1111111 on 2018-8-23 10:29. Hehehe. Little brother, if you think of the floating disc and weight as layered liquid materials, that’s exactly right. Thinking of it as a piston makes it more realistic. The floating disk is sealed to the liquid surface by a rubber ring; therefore, the pressure P1 exerted by the floating disk on the liquid surface is approximately given by P1 = mg/S, where m is the mass of the floating disk, g is the acceleration due to gravity, and S is the cross-sectional area of the tank. As for the frictional resistance of the rubber ring, it is estimated that this value is not high; ignoring it is feasible. Of course, by conducting a physical experiment, it is possible to easily determine exactly how much the resistance is, as well as any variations in that resistance.
Thus, it can be seen that in the diagram drawn by the younger brother, the pressure P3 measured at the single flange is equal to P1 + P2; P2 represents the pressure of the liquid column, while P1 can be eliminated. The rest is something you all understand, so I won’t go into further detail.
If the jar is tall, the impact is minimal. However, it is recommended to use radar; flange transmitters are rarely used for liquid level measurement in large tank farms
You need to understand where the pressure comes from, through mechanical analysis. You should know that both single-flange and double-flange transmitters operate on the principle of differential pressure; in other words, the pressure of the liquid phase equals the pressure of the liquid column plus the atmospheric pressure. This is positive pressure. Negative pressure, with respect to the atmosphere, is also a form of pressure, and by subtracting these values, the pressure difference ρgh is obtained. Even the atmospheric pressure needs to be taken into account, let alone the pressure exerted by the floating disk
Okay, thank you so much, bro:D
There is a radar; the tanks aren’t very tall – they’re generally seven or eight meters high, with the tallest ones reaching 10 meters. . . I had already made my choice when I came to this company. . . It’s also the first time I’ve seen a jar like this with a floating disk
It will affect the transmitter, causing the display to show a level higher than the actual liquid level.
There was once a case where the insulation material of a tank fell and struck the short circuit in the transmitter, causing the short circuit to break and leading to a large leakage of organic substances.
This internal floating roof tank uses a single-flange level gauge; the vapor port (L end) of the single flange must be connected to the vent port on the floating roof. There will be uncertainty, because the air pressure inside the floating roof differs from atmospheric pressure; therefore, atmospheric pressure cannot be used as a reference for measuring the liquid level.
The floating roof is in communication with the atmosphere, so the pressure difference shouldn’t be very large. Moreover, the floating roofs of the tanks here have seven or eight vent holes