RU9524U1 - LIQUID MEASUREMENT DEVICE - Google Patents

Abstract

A device for measuring the level of liquid media, containing a measuring tube with an acoustic emitter of a probing signal and a receiver of acoustic signals, amplifiers-shapers of the probing and received signals, a circuit for measuring the time interval functionally associated with the measured level, and an indicator, characterized in that the measuring tube is selected with diameter d <1.22λ, where λ is the wavelength of the fundamental harmonic of the probe signal, the receiver is mounted below the radiator on the outer surface of the pipe wall and is connected with through the communication transformer, while between the emitter and the upper end of the measuring tube there is a matching element, and below the receiver in the cross section of the pipe there is a matching diaphragm “permeable” for a sound wave and “impermeable” for liquid vapor, below which are made in the pipe wall ventilation holes, while the measurement scheme of the time interval functionally associated with the measured level is made in the form of a microprocessor that implements a given program for controlling the process calculating and measuring the measured liquid level 1 g by the formula 1 l = L - V • t, where L is the distance from the receiver installation plane to the bottom of the tank; V is the speed of sound; t is the measured time interval functionally related to the measured level.

Description

  M0.5 GOiF23 / 28

LIQUID MEASUREMENT DEVICE

The claimed utility model relates to measuring the level of liquid media by the acoustic method and can be widely used in automated control and metering systems in water supply and water disposal in the utilities sector, oil and gas processing industry, and other sectors of the economy related to the production, storage and use of liquid media, but; I "1 atmospheric pressure.

Currently, with the abundance of a wide variety of DESIGNS of acoustic level gauges for measuring the level of liquid in open and closed tanks, it is very urgent to develop and create acoustic level meters that have a simple design, reliable and easy to use, with an acceptable measurement error, providing for the possibility of operational automated metering and control the presence and consumption of liquid media both in the process of their storage and sale, and in the technological process of their production generation, and the predusmatrivshschih the widest range of applications, that is, universal.

A device for measuring the level of liquid Ca. with. USSR N560144, M.KL.5 G01F23 / 28), including an acoustic channel made in the form of a tube with a receiving-emitting device, a probe pulse generator and an electrical measurement circuit. In order to improve the accuracy of measurements, the tube cavity is made with ledges distributed along its axis with a quantization step of a level, and the measurement circuitry contains connected amplifiers-Foggiers, a delay line, a valve, and a pulse counter, as well as a trigger, one from the inputs of which is connected to the output of the probe pulse generator, and the output to the valve, and the amplitude selector, whose input is connected to the output of the receiving and receiving device, and the output to the second input Trigger. - /.

The disadvantages of this device is the extreme .. complicated construction of the acoustic channel, limiting both the accuracy of the measurement and the maximum values of the measured levels. In addition, the installation of a transmitter at the bottom of the tank is capacious. The object is a useful model.

ty) significantly limits the scope of the device.

The ultrasonic level sensor C a is known. with. USSR N 777457, M.cl. GOiF23 / 23), containing a receiving-emitting unit connected to a probe pulse generator and an amplifier, a sawtooth generator, a threshold element, a key, a two-input matching element connected by one of the inputs to the output of the amplifier, and a three-code matching element. In order to increase the accuracy of measurement, a dynamic memory device, a pulse shaper and an adder connected to each other and the other elements of the circuit by the corresponding inputs and outputs are introduced into it.

The disadvantages of this device include:

- a limited range of measured levels due to the use of an ultrasonic wave in a portion of the air medium; transceiver - liquid surface;

- the possibility of reflections and re-reflections of the probe signal from the side walls of the tank, which limits the change of the device in narrow tanks, pipes and lots:

-the complexity of the formation of the information signal.

To control the level of liquid media in closed tanks, a device based on the use of ultrasonic waves C a is known. with. USSR N 877342, M.O.Z. G01F23 / 28), containing emitting and receiving electro-acoustic transducers of normal waves, mounted vertically on the wall of the resonator, a pulse generator, amplifier and indicator. In order to increase the accuracy of measurements by reducing the temperature error, it is equipped with a circuit consisting of a series-connected first waiting blocking generator, a first adder, an integrator, a DC amplifier and a second adder, as well as a second blocking generator looking for the input of the amplifier connected to the output of the first the generator waiting for blocking and the input of the peak detector, the output of which is connected to one of the inputs of the second adder, the output connected to the indicator, the second blocking generator waiting for blocking their input connected to the pulse generator, and the output - to one of the inputs of the first adder.

The main disadvantage of this device is the measurement rod itself, whose measured liquid level is related to the amplitude of the recorded signal. In addition, the limited scope of the application (Tanks with rectilinear side walls) and the complexity of implementation due to the installation of the receiver and emitter on the tank wall should be attributed to the disadvantages.

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A relatively simple acoustic level gauge C pat is known. RF N2010180, M.KL.5 G01F23 / 28), containing a sound guide made in the form of a pipe equipped with a reflector with a slotted surface, an acoustic measuring element connected to the recording unit. In order to simplify the design, a rod waveguide is inserted into it, mounted coaxially in the tube, and the reflector is made 11;) apecidally shaped and mounted on the tube opposite the working end of the waveguide, while the side faces of the reflector are installed at an angle of 60 to the horizontal face of the reflector, which is perpendicular working end of the waveguide.

The disadvantages of this device include the rather complicated design of the sound guide, as well as the presence of a reflector with a polished surface, which significantly limits the scope of the level gauge, for example, in sewage disposal in public utilities, in reservoirs and trays of limited sizes. In addition, the DEVICE is not intended to work in conditions of mechanical vibration and during fluid movement.

The closest in technical essence and the achieved effect (analogue - prototype) of the proposed model is an acoustic level sensor sa.s. USSR N 1530926, m.kl.4 G01F23 / 28), containing a strobe formation trigger, the outputs of which are connected to the first and second inputs of the counter, a frequency temperature sensor and a self-circulating mixing channel containing a one-shot in series, an excitation module, a driving amplifier-Shaper a probing signal and an emitter, as well as a receiver of acoustic vibrations connected to the driver amplifier. In order to increase the noise immunity, the autoshijing channel is additionally equipped with the first and second gating comparators, a delay unit and a source of voltage opacities, connected by the corresponding inputs and outputs to each other and other circuit elements. The emitter and the crust of acoustic vibrations are installed in the measuring tube.

The main disadvantages of the analogue-prototype are caused by the installation of the emitter and receiver of acoustic signals at the same level, which leads to an unreasonable increase in the diameter of the measuring tube, complication of the matching device of the emitter and receiver with the pipe, and the uncertainty in the position of the planes of the Phase centers of the emitter and receiver. In addition, the device is subject to the influence of powerful impulse noise, as well as noise interference, which occur in the region where the signal passes through the zero level.

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The objective of this technical solution is to develop an acoustic liquid level meter with a simple design, low power consumption, reliable and easy to use, with a sufficiently high accuracy and practical measurement), which provides for a wide range of applications, that is, versatility, including multi-channel automated data collection and processing systems.

This problem is solved as follows.

In a device for measuring the level of liquid media containing an exhaust pipe with an acoustic emitter of a sounding signal and a pinch of acoustic signals, amplifiers -01; the probing and received signals are measured, a measurement circuit for a time interval functionally related to the measured level, and an indicator, a measuring tube are selected with a diameter d 1.22 L. where L is the wavelength of the fundamental harmonic of the probe signal. The receiver is mounted below the emitter on the outer surface of the pipe wall and is connected to its cavity through a communication transformer. A matching element is located between the emitter and the upper end of the measuring tube. In the cross section of the pipe, the receiver receiver has an agreed-upon diameter, permeable to a sound wave and impermeable to liquid vapor, below which ventilation holes are made in the pipe wall. The circuit for measuring the time interval functionally associated with the measured level is made in the form of a microprocessor that implements a given program for controlling the process of measuring and calculating the measured liquid level 1zh according to Okormula

1 W L - 1 x L - V X tx,

where L is the distance from the installation plane of the receiver to the bottom of the tank; 1х - distance from the receiver to the surface of the liquid: V - speed of sound; tx is the measured time interval, functionally related to the measured liquid level.

The task in this device is achieved by a combination of the following technical solutions:

- the introduction of a measuring tube with a diameter d 1.22A., where L is the wavelength of the main receiver of the probing signal, it allows the formation of a plane acoustic wave characterized by a rather small linear attenuation and the ability to diffract through holes of small diameter, which ensures 4 hours it provides a reduction in the feasible level of power of the video signal supplied to the emitter, and in tayuku it provides the possibility of installing a sensitive element of the donkey on the outer wall of the measuring tube; installing the receiver below the level of the emitter on the outer wall of the measuring tube provides the possibility of hard fixing of the starting point of reference (the plane of installation of the sensitive element of the receiver), which provides sufficient measurement accuracy when changing the length of the measuring tube, and also eliminates the possibility of occurrence in the pipe intererenshonnyk phenomena that increase the measurement error at certain fluid levels. In addition, the usability and simplicity of the device design is achieved: the introduction of a matching element between the emitter and the upper end of the pipe reduces the power consumption of the device: the introduction of a matching circuit installed below the receiver provides an increase in the reliability and durability of the device, as well as its versatility due to the possibility of connecting the measuring pipe to the required length : the introduction of the microprocessor provides expansion (the functional capabilities of the device with the measurement of level, volume, descent), the possibility of individual adaptation of each device to specific operating conditions, as well as connecting the device to various systems for collecting and processing information: the presence of ventilation holes located below the agreed diaphragm leads to the establishment of a sound velocity practically unchanged from the liquid level, the value of which washes slowly change in accordance with external conditions Temperature, pressure, humidity). The essence of the technical solution (utility model) is illustrated by the drawings, on which is shown: on Oyigl - block diagram of the proposed device for measuring the level of liquid media: in FIG. 2 - time diagrams of the operation of the device. The proposed DEVICE for measuring the level of liquid media, installed in the tank (tank) 1. (see figure 1), contains a measuring tube 2, the diastric of which d is selected from the condition d 1.22A., Where A, is the wavelength of the fundamental harmonic of the probe signal. At the upper end of the pipe 2 is installed acoustic - 5 - 6 emitter 3 of the probing signal. Between the emitter 3 and the upper end of the measuring tube 2 is a matching element 4. made in the form of a ring of elastic material, below the emitter 3 on the outer surface of the wall of the pipe 2 there is a receiver 5 connected to its cavity through a communication transformer 6. The niche of the receiver 5 in cross section pipe 2 is installed consistent with her diaphragm 7, permeable to sound waves and impermeable to liquid vapor, made, for example, in the form of a hydrophobic film located between two elastic rings. Below the diaphragm 7, ventilation holes 8 are made in the wall of the pipe 2. The acoustic emitter 3 and the acoustic signal 5 are connected through amplifiers-Shapers 9, 10, respectively, to the control output and the signal input of the time interval measurement circuit. Functionally associated with the measured level, made in the form of a microprocessor 11 that implements a given program to control the process of measuring and calculating the measured liquid level. The microprocessor 11 is connected to the level indicator 12 by one of its outputs, and also has an additional information output for communication with external devices, for example, a computer for collecting and processing information.

The proposed device for measuring the level of liquid media works as follows.

The microprocessor 11 generates a signal Ozap Sem. FIG. 2a) start the amplifier-Shaper 9 of the probing video signal. From the output of the amplifier-Shaper 9, the generated signal is transmitted to the emitter 3, which emits a probe signal into the measuring tube 2. Through a communication transformer 6, at a time instant 1 isol, the PROBING signal is fed to the input of the receiver 5, where it is converted into an electric signal, Digital and amplification. From the output of the receiver 5, the signal and the signal goes to the input of the amplifier-Shaper 10, where a short video pulse is formed from it, the leading edge of which corresponds to the probe pulse entering the input of the pin 5. The conditional representation of the pulse and the pulse is presented in Fig. 26.

The probe signal, having reached the surface of the liquid and reflected from it, again through the communication transformer 6 at the instant of time toTD arrives at the input of the receiver 5. The smeared reflected signal UoTo, similarly to the probe, after conversion and amplification is fed to the input of the amplifier-Shaper 10, where it is formed a short video pulse, the front of which corresponds to the receipt of the reflected signal at the input of the reception- 7 -

nick 5. The conditional representation of the UOTD pulse is shown in FIG. 26.

The video pulses of izl and UOTD are fed to the information input of the microprocessor 11, where the measuring intv1 shaft tx Sem is formed from them. FIG. 26), functionally related to the measured liquid level 1zh expression

1g - L - V to tx.

where L is the distance from the installation plane of the receiver 5 to the bottom of the receiver: V is the speed of sound: tx is the measured time interval, functionally related to the measured level of the liquid-p.

The microprocessor 11 calculates the liquid level in. capacity 1 and gives the result of the calculation to a digital indicator 12 and additional info1; I "lationary output of communication with external devices, for example, ES.

Thus, the proposed device for measuring the liquid level has low energy consumption, provides 1 wide range of applications (open, closed, underground tanks and trays), has a fairly simple design, is technologically advanced in manufacture and operation, and provides measurement accuracy acceptable in practice. In addition, the proposed device is a flexible processor system that provides operation both in an individual version and in a data acquisition system with the representation of information in DIGITAL and analog forms.

Currently, the DEVICE has been created, it has been tested in maintenance-free mode under real conditions of Preserving with drinking water), which have confirmed its reliability, noise immunity, low power consumption, sufficient accuracy of the measured levels, the ability to work in conjunction with existing information collection systems.

Authors: B. V. Zhukov

A.A. Voronin, Yu.A. Andr. No. 1, V. Zykov, A. and. Cherepkov. M. Spalek

Claims (1)

A device for measuring the level of liquid media, containing a measuring tube with an acoustic emitter of a probing signal and a receiver of acoustic signals, amplifiers-shapers of the probing and received signals, a circuit for measuring the time interval functionally associated with the measured level, and an indicator, characterized in that the measuring tube is selected with diameter d <1.22λ, where λ is the wavelength of the fundamental harmonic of the probe signal, the receiver is mounted below the radiator on the outer surface of the pipe wall and is connected with through the communication transformer, while between the emitter and the upper end of the measuring tube there is a matching element, and below the receiver in the cross section of the pipe there is a diaphragm matched with it, “permeable” for a sound wave and “impermeable” for liquid vapor, below which are made in the pipe wall ventilation holes, while the measurement scheme of the time interval functionally associated with the measured level is made in the form of a microprocessor that implements a given program for controlling the process nii and calculation of the measured liquid level 1 g according to the formula
1 w = L - V • t _x ,
where L is the distance from the installation plane of the receiver to the bottom of the tank;
V is the speed of sound;
t _x is the measured time interval, functionally related to the measured level.