RU1784899C - Method of phase separation degree determining for emulsion flow - Google Patents

Abstract

Usage: analytical instrumentation. SUMMARY OF THE INVENTION: by the method, the time ti of the passage of the electrically conductive part of the flow and the time ta of the passage of the non-conductive part of the flow are measured using electrode sensors and a converter. At the same time, the resistance RI of the emulsion in the upper part of the pipeline is measured with an electrode sensor and a converter, and the resistance R2 of the emulsion in the lower part of the pipe is measured with another electrode sensor and a converter. The ratios ti / t2 and Ri / Ra are measured with a ti / t2 ratio and the degree of separation of the variable component of the flow is determined by the ratio ti / t2, and the degree of separation of the constant component of the phase by the ratio of Ri / R2 is judged. 1 ill. (/

Description

A method for determining the degree of phase separation of an emulsion stream in a pipeline is intended for automatic determination of water-in-oil emulsions, for example, during in-line de-emulsion of oil in oil refining processes.

The method can find wide application, for example, in automatic dispensing systems for demulsifiers in oil treatment plants, as well as in the chemical industry for similar purposes.

A known method for determining liquid droplets in a stream, based on measuring the electrical conductivity of liquid droplets, using a droplet eliminator of fibrous hydrophobic material, which

it only captures liquid droplets. This method has a low sensitivity of control, and since it is based on the integration of the electrical conductivity of the liquid over time, it does not allow controlling the variable component of the flow.

A prototype of the invention is a method based on measuring the instantaneous electrical conductivity of a liquid, in which the percentage of each liquid in the mixture is statically determined from the average electrical conductivity for a given time.

In the known method, the average value of the flow resistance over the entire cross section of the pipeline, i.e. the integral value of the entire flow is measured and, therefore, selectivity is not ensured

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control by variable and constant flow components. In addition, the method directly measures the electrical conductivity of the emulsion; with such a measurement, insignificant changes in water cut cause correspondingly insignificant changes in the conductivity of the emulsion, and therefore it is able to give low sensitivity.

I The purpose of the invention is the realization of the possibility of selective control over the variable and constant components of the flow and an increase in sensitivity.

This goal is achieved in that by the method of determining the degree of separation of the emulsion flow in phases in the pipeline, based on measuring the electrical conductivity in time, the transit time ti of the electrical conductive part of the flow and the transit time i of the non-electrical conductive part of the flow, the electrical resistance of the flow in the upper RI and lower R2 part are measured x of the pipeline, the ratio ti / t2 is calculated, according to which the degree of separation of the variable component of the flow by phases is judged, and the rib value of RI / RZ is judged by the degree of separation of the constant component th flow in phases.

The drawing shows a diagram for implementing the method.

Pipeline 1 passes water-oil emulsion. A demulsifier is introduced into the pipeline to separate the emulsion in oil-water phases at point 2. At a predetermined distance from the demulsifier entry point, an electrode sensor 3 is installed in the upper part of the pipeline and a sensor 4 in the lower part. The outputs of sensors 3 and 4 are connected to the inputs of the converter 5.

Converter 5, receiving electrical signals from sensors 3 and 4, generates electrical signals proportional to time ti and vi. Time ti corresponds to the transit time of the electrically conductive part of the flow through the electrode sensors 3 and 4, time ta to the transit time of the non-conductive part of the flow.

At the same time, the converter 5, through the sensor circuit 3, provides a measurement of the resistance RI of the emulsion (crude oil) flowing in the upper part of the pipeline 1, and along the sensor circuit 4, it measures the resistance Ra of the emulsion (crude oil) flowing in the lower part of the pipeline 1. Measurement of the resistance RI and Ra is carried out relative to the pipe body 1. From the converter 5, the output signals are supplied to the calculator 6, where the ratio ti / t2 and the ratio Ri / R2 are automatically calculated. The calculation result ti / t2 is supplied to the measuring device 7. The calculation result R1 / R2 is supplied to the measuring device 8. On devices 7 and 8, the measurement results are displayed 5.

Determination of the degree of separation of the emulsion by phases is carried out in the pipeline section 1 through which the water-oil passes through the emulsion. For separation

In a water-in-oil emulsion in phases, a demulsifier is used, which is introduced through the nozzle (point 2). As a result of turbulent mixing of the emulsion stream with the demulsifier droplets of the aqueous phase

5 are mixed with it, in the process of coalescence, water droplets coarsen and the latter begin to precipitate under the influence of gravitational forces. In the lower part of the pipeline 1 along its length begins

0 water prevails per phase, and in the upper oil increases correspondingly to the phase of the flow, which form the constant components of the flow.

Since the oil-water phase boundary is subject to turbulent pulsation, a pulsating flow is established in the middle part of pipeline 1, in which the oil and water phases alternate, i.e. an alternating current component is formed.

The degree of separation of the variable and the constant components of the flow is determined as follows.

The middle part of the cross-section of pipeline5 is 1. where the variable component flow passes, it is monitored by electrode sensors 3 and 4. When the resistance between the electrodes 3 and 4 decreases below a predetermined value (for example, below 500 Ohms)

0, converter 5 is automatically turned on and an electrical signal is generated corresponding to the time ti of passage of the electrically conductive part of the flow until the resistance between the electrodes 3 and

5 4 does not increase sharply, converter 5 will begin to generate an electrical signal corresponding to the passage time t2 of the passage of the non-conductive part of the flow, i.e. oil phase.

0 Converter 5 stores the time ti and t2, then the electrical signals corresponding to ti are supplied to calculator 6, in which the calculation is automatically performed. The result of calculating ti / t2 by 5 is given to the measuring device 7. The ti / t2 value determines the degree of separation of the emulsion into phases of the variable component of the flow.

With intensive separation of the emulsion

for oil and water, in relation to ti / t2, simultaneously with decreasing time tz, the time ti increases (i.e., increasing the numerator while decreasing the denominator). This, in turn, provides a sharp increase in the absolute value of the ti / ta ratio and a high sensitivity for controlling the separation of the emulsion.

At the same time, with the help of sensor 3 and converter 5, the resistance of the RTemulsion (crude oil) flowing in the upper part of the pipeline 1 is automatically measured, with the help of the sensor 4 and the converter 5, the resistance of the P2emulsion. {Crude oil) flowing in the lower part of the pipeline is automatically measured 1. The measurement of resistances RI and Ra is carried out relative to the pipe body 1.

The values of RI and R2 are judged by the presence of constant components of the flow in oil-water phases, with water per phase prevailing in the lower part of pipeline 1 and measured by sensor 4, and oil in the upper one and measured by sensor 3.

Computer 6 automatically measures the resistance Ri / R2. The result of the calculation of Ri / R2 is supplied to the measuring device 8, where the measurement results are displayed.

During the intensive separation of oil and water along the length of pipeline 1, water accumulates in the lower part per phase, and in the upper part - yefte.

Therefore, with a good separation in the oil and water pipeline, the resistance value RI in the ratio Ri / R2 increases (because the amount of water in the emulsion decreases in the emulsion), and the resistance value R2 decreases (because in this part of the pipeline water increases). This provides high sensitivity to control the degree of separation of the oil-water phases of the constant component of the flow.,,

The proposed method makes it possible to effectively control the process of separation of a water-in-oil emulsion in pipelines when demulsifiers are introduced.

Claims (1)

The claims A method for determining the degree of phase separation of the emulsion flow based on measuring the conductivity over time, characterized in that in order to enable selective control of the variable and constant components of the flow and to increase the sensitivity, the transit time ti of the electrically conductive part of the flow is measured and the time t2 of the passage of the non-conductive part of the flow, the electrical resistance of the flow in the upper RI and lower Ra parts of the pipeline, the ratio ti / t2 is calculated, from which the degree p Thousands separator variable component stream of the phases and of Ri / R2 value is judged on the degree of separation D.C. flow of phases. /; YS /; S ;;; / S / S ;; S / SS / SSS7. Jt