SU1629684A1 - A monitor of the passage of purifying objects in pipelines - Google Patents

Abstract

The invention relates to pipeline transport and can be used in the petroleum industry to control the movement of pipeline scrapers, separators, containers, etc. in a stream of oil. The purpose of the invention is to improve the noise immunity of the control and the accuracy of determining the time of the cleaning device passing through the control point. This goal is achieved using an ultraband bandpass filter operating in the frequency range above 100 kHz and having a bandwidth of 3-10 kHz. In this frequency range, a maximum signal to noise ratio is provided. An impulse formed on the basis of this signal by processing it against a reference voltage passes a time delay and then includes an actuator. The device provides the maximum ratio of signal and noise and allows to increase the noise immunity of the control and the accuracy of the cleaning point of the control point. 3 il.

Description

The invention relates to pipeline transport and can be used in the petroleum industry to control the movement of pipeline scrapers, separators, containers, etc. in a stream of oil.

The purpose of the invention is to improve the noise immunity of the control and the accuracy of determining the time of the passage of the cleaning object through the control point.

Fig. 1 shows a block diagram of a device for controlling the passage of cleaning objects in pipelines; Fig. 2 shows experimental frequency characteristics of the acoustic radiation of the cleaning devices when passing through the main oil pipeline (curve a - equipment noise, curves b, c - noise of the oil flow before passing through the scraper, curve g - noise of the oil flowing after passing the scraper, curves d, e - acoustic radiation generated by the cleaning device, a manzhetorezinovy scraper type SMR and a scraper of variable diameter type SPD, respectively); FIG. 3 shows graphs of the output voltages of the functional units of the device: integrator (a), comparator (b), time delay circuit (c), actuator (d).

The device for monitoring the passage of cleaning objects in the pipelines (Fig. 1) contains a series-connected receiving transducer 1, an amplifier 2, and a narrowband bandpass filter 3 frequencies.

O N3 S O 00

Amplitude detector 4, integrator 5, comparator 6, time delay circuit 7, actuating element 8 and indicator 9. A piezoelectric transducer can be used as a receiving transducer.

The narrowband bandpass filter 3 operates in the frequency range above 100 kHz and has a bandwidth of 3-10 kHz. In the specified frequency range, the maximum signal-to-noise ratio is equal to 40-50 dB, while at lower frequencies this value is at best 28 dB (Fig. 2). The integrator 5 is designed to eliminate spurious operation due to external impulse noise of mechanical origin. The time constant of the integrator circuit t is chosen equal to 0.1–0.5 s on the basis of experiments and data from the ratio T 100000 Ti, where t is the time constant of the integrator circuit; Ti is the duration of the external pulses of mechanical origin.

The device works as follows.

When a cleaning object (00) moves in the pipeline, acoustic radiation arises, the main energy of which is concentrated in the frequency range up to 200 kHz due to friction 00 against the pipe wall, impact 00 with the pipe wall, and fluid throttling through the gap between 00 and the pipe wall. The receiving transducer 1, mounted on the outer wall of the pipeline, converts the acoustic oscillations generated by 00 into an electrical signal and supplies it to the wideband amplifier 2. The signal amplified over the entire frequency range from amplifier 2 is fed to the narrow-band filter 3 and further to the amplitude detector 4. A rectified voltage, proportional to the acoustic radiation at any given time, is applied to the integrator 5, which records a certain average value of the acoustic radiation signal i (Fig. 3a). Two signals are supplied to the input of comparator 6: the integrator output voltage Uc and the reference voltage Don, defined by

Don 5: 0.5 Umaks,

where Umax is the maximum value of acoustic radiation generated by 00.

When the comparator 6 is triggered and produces a pulse (Fig.36), the leading edge of which triggers the circuit 7 time delay. The latter provides for the delay of the leading edge of the pulse from the comparator 6 for the time spent by the cleaning device on half the area where. The impulse from the output of the time delay circuit (fig.Zv) by the falling edge includes the actuating element 8, which, with its contacts, actuates the audible and visual alarms (indicator 9) and the actuators of the automatic pipeline unit.

The device provides the maximum signal-to-noise ratio (12-25 dB higher), elimination of false alarms and thereby makes it possible to increase the noise immunity of the control and the accuracy of determining the time that the cleaning device passes through the control point. Using the device will automate and control the process of starting and receiving cleaning devices, which will increase the reliability and performance of pipeline transport.

Claims (1)

Invention Formula A device for controlling the passage of cleaning objects in the pipelines, comprising a series-connected receiving transducer, an amplifier, a pulse shaper, a delay element, and a signaling device, characterized in that. in order to improve the noise immunity of the control and accuracy of determining the time of the cleaning object passing through the control point, the device is equipped with a narrowband frequency filter, whose input is connected to the amplifier output, the pulse driver is designed as a series-connected amplitude detector, integrator and comparator, and the signal device is made as a series connected actuator and indicator. Amplifier signal, µV one about year     .K t-i / mls Fig.Z