One of the main challenges for today's refinery technology is to produce higher quality and environmentally safe end products from crude oil of deteriorating quality.
The wash bed is a particularly sensitive part of every vacuum distillation column. Long retention times of the oil fractions and low flow rates cause frequent fouling and coking, which involve the system being shut down prematurely for extensive maintenance work.
Using modern CFD software, processes can be controlled, so that fouling and coking are effectively prevented and optimal yield of the desired end products can be produced from the crude oil used. Moreover, reliable flow measurement of all partial currents is necessary for CFD-assisted process control.
In one of the most complex refineries in Europe, replacement for an unreliable flow measurement system for monitoring the heavy vacuum gas oil streams at the reflux pipe leading to the wash bed was sought. The measuring point was located at the heavy gas oil outlet of the vacuum distillation tower, in an ATEX zone 1 rated area.
The gasoil flowing here had a temperature of approximately 570 °F. Clamp-on flow measurement with the WaveInjector proved to be the superior solution for this measuring task.
Due to the high dynamic range of the meter, even small flows could be measured and unlike inline flow measuring systems which work according to the pressure differential principle, clamp-on transducers do not cause any pressure losses inside the pipe.