The issue of measuring liquid level stratification
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The operating condition is a static stratification, with dichlorotetrafluorotoluene in the upper layer, hydrogen fluoride, water, and sodium fluorohydroxide in the lower layer, and a small layer of tar in between. I want to achieve automatic layered discharge by using a measurement interface. What instruments are suitable to use?
Upper layer density 1.2, lower layer density 1.4
These types of level measuring instruments are generally float-type level gauges and differential pressure level gauges
Generally, the common methods for measuring the level of layered media include the following. 1. Magnetic flap level gauge: This measurement method requires a density difference between the media in the upper and lower layers; generally, a density difference of 100 kg/m3 or more between these layers is sufficient to enable relatively stable measurement. 2. Director radar: This measurement principle relies on the different dielectric constants of the upper and lower layers of medium, allowing the level of the layered liquid to be determined through two reflections. The manufacturer needs to adjust the parameters and set thresholds; it seems there are also requirements regarding the difference in dielectric constants between the upper and lower layers of material. 3. Float level gauge: The measurement principle of the float level gauge is also based on the difference in density of the medium. The medium density at the site needs to be accurate and stable. It should also be noted that when the upper medium (light medium) fills the tank, it serves as the zero point for measurement. All of the above measurement methods require consideration of the properties of the medium at the site. Such as temperature, density, pressure, corrosivity, and so on.
Specializing in layering of instruments, extraction, washing, and spectral analysis of intermediate layers
Assuming the densities of the two liquid layers are 1.2 and 1.4, and if the liquid level height is 1 meter, the pressure at the bottom of the liquid will be 14 KPA if it’s all 1.4, and 12 KPA if it’s all 1.2. Two pressure gauges with a low range can be used; by measuring the pressure difference between them, one can determine this value. By keeping the pressure difference around 13 KPA, the liquid level will be at the center of the stratifier. Or use a differential pressure gauge directly
The resolution of the differential pressure gauge is 2 per thousand; if its range is 20 KPA, it can detect changes of 10 Pa. With pressure fluctuations within the range of 12–14 KPA, the amplitude of these fluctuations is 2 KPa, which allows the gauge to detect variations equal to one 200th of that amplitude, thus enabling detection of the boundaries between different layers.