SU1569558A1 - Liquid flowmeter - Google Patents

Abstract

The invention relates to the field of measuring the flow rate of liquids by nuclear magnetic resonance. The purpose of the invention is to improve the measurement accuracy and expand the range of measurable flow rates. The measured liquid enters the pipeline 4, made in the form of a loop, passes through the analyzer coil 5, where its nuclear magnetization changes, returns through the loop to the same coil, where the signal of nuclear magnetization is recorded, and the flow is judged by the time interval between the signals changes and registration of nuclear magnetization. When the flow rate changes, the loop of pipe 4 is moved relative to the analyzer coil 5, increasing the path of the fluid in the measurement zone. 2 Il.

Description

The invention relates to measuring flow rates of a fluid by the method of heavy magnetic resonance (NMR),

The purpose of the invention is to improve the accuracy and expand the range of flow measurement.

Figure 1 shows the flow diagram of a liquid flow meter; Fig, 2 - timing charts characterizing the operation of the flow meter.

The flow meter contains a magnetic system 1 of the polarizer and analyzer, modulation coils 2 connected to modulation generator 3, pipeline 4, made in the form of a loop, both branches of which are located inside the analyzer coil 5 fixed relative to the magnetic system and ensure the movement of the fluid in each of them in opposite directions, the mechanism 6 for moving the pipe at the moment of the mark (Fig. 2, b), the namination of the fluid in the coil 5 changes sign, for some time t ,, the marked participant is carried out by the flow and From the coil, the magnetization changes and after the label has completely reached the previous value equal to the magnetization of the unmarked liquid. Next, the label moves with the flow velocity of the liquid along the closed loop loop and again enters the analyzer coil 5, which results in The magnetisation of the volume of this coil. At the moment of passing the 20 marks through the coil 5 of the analyzer, the sign of the average magnetization in the volume of the coil does not change, since in this case one branch of the pipeline is filled with the marked one, and the other is not marked.

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pipeline along the axis of the analyzer coil, connected to the pipeline and made, for example, in the form of a threaded liquid.

element, the spin detector 7, Thus, in the signal from the output connected to the analyzer coil, a pulse generator 8, the outputs of which are connected to the inputs of the spin detector 7 and the time interval measurement unit 9, the display device 10 and the synchronous detector 11. The input of the device 10 the display is connected to the output of the time interval measurement unit 9. The inputs of the synchronous detector 11 are connected to the modulation generator 3 and the spin detector 7, and its output is connected to the second input of the time interval measurement unit 9.

The flow meter works as follows.

The measured liquid is passed through conduit 4. In the constant field of the magnetic system E of the polarizer and the analyzer, it acquires nuclear magnetization and then enters the analyzer coil 5, in which volume the nuclear magnetization is alternately produced and analyzed using a spin detector generated by the generator of 8 pulses. The amplitude of the radio frequency field in the analyzer coil 5 is changed in a pulsed manner (Fig. 2, a):

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In addition, a synchronous detector, proportional to the magnetization in the coil, contains information on the time the tag leaves the coil t, and the time it takes the tag to move along the loop t. The time interval measurement unit measures time intervals t, and tz inversely proportional to the flow rate. The device for moving the pipeline along the axis of the coil, which is an adjustable threaded element connected to the pipeline, allows the length of the measuring section, the closed loop part, to be varied.

Claims (1)

Invention Formula A liquid flow meter comprising a pipeline installed between the magnetic system's poles, a modulation coil, an analyzer coil disposed coaxially on the pipeline, and a recording circuit connected to the modulation coils and the analyzer, in order to improve the accuracy and expanding the range of measurable flow rates, the pipeline is designed as a loop, the process of marking corresponds to a large magnetic pole installed at the poles. katugake and analyzer, and the register-. is small, optimal for observing the NMR signal. At the time of the mark (Fig. 2, b), the magnetization of the fluid in the coil 5 changes sign, for some time t, the marked portion is carried by the flow from the coil, and the magnetization changes and after the full exit of the mark takes the same value as the magnetization unmarked fluid. Next, the label moves with the velocity of the fluid flow along the closed loop section and again enters the analyzer coil 5, which leads to a change in the magnetization in the volume of this coil. At the moment of passing the 0 mark through the coil 5 of the analyzer, the sign of the average magnetization in the coil volume does not change, since in this case one branch of the pipeline is filled with the marked one and the other - 5 liquid. Thus, in the signal from the output Yes, a synchronous detector, proportional to the magnetization in the coil, contains information on the time the tag leaves the coil t, and the time it takes the tag to move along the loop t. The time interval measurement unit measures time intervals t, and tz inversely proportional to the flow rate. A device for moving the pipeline along the axis of the coil, which represents an adjustable threaded element connected to the pipeline, allows the length of the measuring section, the closed loop part, to be varied. Invention Formula A liquid flow meter comprising a pipeline installed between the poles of the magnetic system, a modulation coil, an analyzer coil placed coaxially on the pipeline, and a recording circuit connected to the modulation coils and the analyzer, in order to improve accuracy and the range of measurable flow rates, the pipeline is designed as a loop, installed at the poles of the magnetic the amplitude providing the inversion of the nuclear magnetisation of the liquid in systems that can be moved along the axis of the analyzer coil. “; .Z