Schematic diagram of liquid level measurement of a typical combination reaction in a chemical plant. Above is oil (benzene and its compounds) and below is liquid catalyst. Due to the higher density of the catalyst compared to oil, the two materials will automatically separate. The process operator ensures the generation rate of combination reaction by controlling the catalyst, oil interface (LT1 measurement) and oil level (LT2 measurement). The two liquid level values must be accurately controlled within a certain range, which is the system shutdown interlocking point.
Due to the relatively fixed density of the position where the float is located, the percentage of oil and catalyst contained is relatively fixed. From the above formula, it can be seen thatρ 1、ρ 2 is relatively fixed, and the buoyancy exerted on the float is fixed. The float floats accurately at the interface and liquid level, ensuring the high-precision measurement of the magnetostrictive liquid level gauge.
The magnetostrictive liquid level gauge can simultaneously measure the liquid level and interface, and the accurate height of the oil can be obtained by adding or subtracting the liquid level value from the boundary value in the DCS module. This solves the problem of LT2 in Figure 1, which can only measure the upper part of the oil level, and enables process operators to have a clearer understanding of the situation inside the reactor. The use of steam tracing in the differential pressure transmitter pressure pipe in winter can cause liquid vaporization inside the pressure pipe. It is necessary to regularly exhaust and fill the isolation liquid. When there are impurities in the material, it can cause instrument blockage, and the workload of instrument maintenance personnel is large. After using a magnetostrictive level gauge, the amount of instrument maintenance is much reduced.
As an emerging measuring instrument, magnetostrictive level gauges have the advantages of high accuracy, stability, and reliability. More suitable for interface liquid level measurement, there will be a larger market in industries such as petroleum, chemical, and pharmaceutical in the future.