System for accurately measuring and automatically correcting liquid level of absorber oil regenerator in crude benzene coking unit

Abstract

The invention provides a system for accurately measuring and automatically correcting the liquid level of an absorber oil regenerator in a crude benzene coking unit system. The system comprises a liquid level transmitter and a liquid level switch, wherein the differential pressure transmitter and the liquid level switch are both connected with a DCS; the liquid level transmitter is mounted at the bottom of the absorber oil regenerator and is used for measuring the liquid level of the regenerator in real time; and the liquid level switch is mounted at the upper part of the wash oil regenerator, and a height difference between the liquid level switch and the liquid level transmitter is H. According to the invention, when the DCS detects that the liquid level switch is ON, density correction calculation is triggered, the liquid level height h measured by the liquid level transmitter is compared with the height H of the liquid level transmitter, the height H serves as a correction value, and a new liquid density value rho1 is calculated; the new liquid density value rho1 is substituted into the liquid level calculation of the liquid level transmitter in the next round; and whenever the liquid level of the regenerator reaches the height position of the liquid level switch, the DCS corrects the measured value of the liquid level transmitter once by using the height difference H, so the accurate measurement of the liquid level is realized.

Description

technical field [0001] The invention relates to the technical field of coking and coal chemical industry, in particular to an automatic correction system for accurate measurement of the liquid level of an oil washing regenerator of a coking crude benzene unit. Background technique [0002] In the field of coking, the benzene recovery of coke oven gas mainly adopts the oil-rich debenzene removal process. In order to maintain the quality of the circulating oil, a part of the circulating oil is led out and sent to the regenerator for regeneration. Here, the washing oil is heated by indirect steam and superheated. Steam blowing, the oil-gas and water-gas mixture blown from the top of the regenerator is sent to the crude benzene tower again. The high boiling point polymer at the bottom of the regenerator is intermittently or continuously discharged to the residual oil tank as residual oil. The operation of the washing oil regenerator has a great influence on the washing oil cons...

AI Technical Summary

Problems solved by technology

[0003] Usually the liquid level is measured using a double-flange liquid level transmitter. This method needs to know the density of the medium in the regenerator in advance, and the medium of the oil washing regenerator is a mixture, and the density varies with the components of the washing oil, crude benzene, etc. The working conditions of the tower and the regenerator often change, resulting in a wide range of density fluctuations. According to the conventional calculation method, there are essential errors in the liquid level measurement, which affects the measurement accuracy of the regenerator liquid level.

Many sites often require maintenance personnel to measure the density off-line to realize liquid level correction calculations, which affects the operation accuracy of the oil washing regenerator, and it is difficult to achieve precise control of the liquid level

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