Selection of level gauges
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There is a 500-cubic-meter crude oil storage tank equipped with a mesh-shaped steam heating coil at its bottom. It is necessary to install a level gauge. Two types of instruments are being considered: 1) Differential pressure level gauges; however, since crude oil contains many impurities and tends to solidify in winter, this might pose a problem. 2) Radar level gauges; but given the presence of the steam heating coil at the bottom of the tank, this could also affect the accuracy of measurements. Dear experts, are there any other options?
This tank is very small; it’s likely a atmospheric pressure tank, so a single-flange pressure transmitter will suffice for measurement.
Now, steam doesn’t pose any problem for radar
The differential pressure position is not very reliable, especially in scenarios where icing might occur.
Radar is feasible, but it is generally not recommended to use it in tanks that are under vacuum, as condensation will form on the radar and lead to false readings. Oil tanks are generally equipped with nitrogen sealing, so condensation is not too severe. If the standard is GB17681-1999, two types of level gauges based on different principles are required, which will prevent issues with inaccurate readings.
Ordinary radars can be equipped with signal suppression, which serves to block out the signal interference caused by water vapor, and the effect is quite good. If radar is used, it is possible to have the manufacturer make the necessary settings
I also prefer radar level gauges. The storage tank is at atmospheric pressure and has a grid-shaped steam coil at the bottom; will the use of a radar level gauge be affected by this coil?
It can be solved using a VEGA radar. Or, if the insulation and heating are in order, there’s no problem using an insert-type differential pressure level gauge
As long as interference suppression is properly implemented when the tank is empty, radar level gauges can generally ignore the false echoes caused by steam. However, the radar horn antenna tends to freeze easily in winter.
Imported radar level gauge; steam has no effect. A nitrogen purge can be applied to prevent condensation