MXPA98008800A - Device for detecting the concrete speed profile that flows in a tube - Google Patents

Abstract

A device to detect the velocity profile of concrete flowing through a pipe with radial symmetry. It comprises an acoustic probe, suitable for sending through the pipe and concrete a supersonic beam inclined with respect to the axis of the pipe and to receive a supersonic beam distributed in response, as well as an electronic circuit capable of analyzing the signals sent by the probe means and to obtain from them a diagram showing the velocity profile of the concrete. According to the invention, the probe means makes use of a supersonic radio frequency between 20 and 500 kHz, and the electronic circuit processes the signals sent by the probe means, indicating the speed, with an update frequency of 10 to 70 times per second and suppresses the signals of its components derived from the speed of propagation in the concrete, to obtain a measurement of the speed along the acoustic axis, which is not relative and has its own sig

Description

DEVICE FOR DETECTING THE CONCRETE SPEED PROFILE THAT FLOWS INTO A PIPE DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting the velocity profile of concrete within a pipe with radial symmetry through it. which causes the concrete to flow. Processes and devices are already known to detect the velocity profile of heterogeneous fluid mixtures flowing through ducts. Such processes and devices have generally been developed in the medical and biological field, for organic and / or physiological liquids of limited density and low viscosity -such as, for example, blood-, the heterogeneities of which have dimensions of several orders of magnitude below the size of the ducts through which they flow, which are of small or very small dimensions. Meanwhile, the problem has never been faced to detect the velocity profile of fluids having a high density and a very high viscosity, such as concrete, the heterogeneities of which have dimensions of the same order of magnitude or close to those of the pipelines -always large diameter pipes- through which they flow. In fact, the prior art comprises: the DI publication, in relation to a tomographic method that uses ultrasound in the technical domain; The subject matter of this application is completely foreign to the problem faced and solved by the present invention; - the patent D2, which performs a measurement similar to that of the invention with the use of an inclined ultrasonic ray, but makes such a measurement in non-homogeneous liquid or paste fluids such as concrete; therefore it does not solve the problem of the invention,. Publication D3, which refers to the measurement using ultrasound in cement, where, as is known, the phenomenon of ultrasound is not a propagation (as in concrete, in which the measurement of the invention is concerned), but a diffusion; therefore it does not provide interesting information regarding the problems of the invention; and the publication D4, which also uses ultrasounds, but with the objective of testing materials and not with the objectives of the invention. Instead, the aforementioned problem is addressed and solved by the present invention, which provides a device for detecting the velocity profile of concrete within a pipe with a radial symmetry, through which the flow is caused to flow. concrete. Such a device - of the type comprising acoustic probe means, is apt to send through the pipeline, and to the concrete flowing therein, a supersonic beam inclined with respect to the axis of the pipe, and to receive an altered supersonic beam in response, as well as an electronic circuit, suitable for the analysis of the signals sent by the probe means and to obtain from them a diagram showing the profile of the velocity of the concrete- is characterized in that the probe means makes use of a supersonic ray of frequency between 20 and 500 kHz, and the electronic circuit processes the signals sent to the probe means, indicating the speed, with an update frequency of 10 to 70 times per second, and suppresses the signals of its components derived from the speed of propagation in the concrete, to obtain a measure of the speed along the acoustic axis, which is not relative and has its own sign. The detection device allows displaying velocity measurements as a velocity profile. In addition, it allows to measure the flow velocity, as an integral speed with respect to the area section, and also allows viscosity measurements as first derivatives of velocity in space, as well as measurements of particle size and density through a statistical analysis of a package of speed profiles. For economic reasons and to simplify the conction and operation, it is usually convenient to adopt, in the detection device according to the invention, a probe means in which the transmitting and receiving waves coincide. Suitably, such probe means will be applied in a pipeline so that the supersonic beam, of which it makes use, is inclined at 15 ° to 75 ° with respect to the axis of the pipe. The invention will now be described in more detail with reference to the accompanying drawings, which illustrate a preferred embodiment of the detection device defined in the foregoing, and in which: Figure 1 depicts a block diagram of the detection device according to the invention; Figures 2 2A are diagrams illustrating, in two orthogonal sections, the application of the acoustic probe, which covers part of the detection device of Figure 1, to a pipe for distribution of concrete; Figure 3 illustrates the propagation, in the pipe, of the supersonic beam emitted by the probe in various concrete components traversed by the beam; and Figure 4 represents an example of a concrete velocity profile that is caused to flow within a distribution pipe, such as that shown in the detection device according to the invention. With reference to the drawings, the detection device according to the invention is of the type that makes use of a ray r. supersonic (figures 1 and 2), with a frequency between 20 and 500 kti, sent through concrete that flows through a pipe C; the device operates by detecting the alteration that appears in the response ray r_ (Figures 1 and 2A), depending on the irregularities derived from the heterogeneous composition of the concrete, which influences the propagation of the ray r '. In the detection device it is applied in the pipe C so that the supersonic beam, of which use is made, is inclined from 15 ° to 75 ° with respect to the axis of the pipe (figure 2). As shown in Figure 1, the device consists of a transmitter probe 1 which sends the beam r. supersonic suitably inclined to the pipe C through which the concrete flows, so that it passes through the latter and is altered and propagated in this manner, of a receiving probe 2 which collects the altered ray £ arising from the pipe C , and of the reception circuit to which signals produced by the receiver probe 2 are fed. The receiver probe 2 is placed in the same plane as the transmitter probe 1 forming any angle α with it (see Figure 2A) and with which it can also coincide, preferably it is caused to coincide (as shown in Figure 2) with the advantages such as costs and simplicity of the device - with the transmitting probe. In the reception circuit, the signals sent by the receiver probe 2 are amplified by a logarithmic amplifier 3, with a gain which varies according to time, that is, with the distances of the propagation points from which the signals are transmitted .The amplified signals are sent to a decomposition circuit 4 without wattless: this is a simple circuit (preferably a very cheap RC unit) which recovers the real part and the imaginary part of the signals by sending them separately to the circuits 5 and 6 of derivation , which are controlled by a sampling circuit 7. In branch circuits 5 and 6 (preferably, two simple and inexpensive digital shunts) the real and imaginary parts of the signals are derived. The base of derivation time of the shunts 5 and 6 is chosen so that, for each instant, a position corresponds in the space of the advance of the echo signal in the pipe C: one therefore analyzes in a way that is capable to obtain the desired profile, the mass of concrete moving in pipe C, section by section, along the axis of the supersonic beam and at pre-established distances from the sampling interval. Figure 2 illustrates, by way of example, a series of sections =. The signal emitted by the bypass circuit 5 is multiplied by the signal emitted by the bypass circuit 6 and is sent to the correlator 9, while the signal emitted by the bypass circuit 6 is changed by a sign, is multiplied by the emitted signal by the bypass circuit 5 and then sent to the correlator 8. The correlators 8 and 9 are controlled by the sampling circuit 7, in such circuits, the real and imaginary parts of the signals of each section are correlated so that it is possible to recover the speed, along the axis of the supersonic ray, of the particles in each section. By identifying the walls of the pipe as the sections which, by definition, are without speed, it is possible to return the independent measurement of the velocity of propagation in the concrete (the particular concrete in the special conditions in which meanwhile it flows within pipe C) and from the angle of refraction of the supersonic beam in the concrete passage of the wall of the pipe (see Figure 3), and to obtain an absolute measurement (and not a relative one, as it happens in the detection devices). known in the medical and biological field) of the speed in each section (each measurement with its own sign). The processing must occur with an update frequency by the sampling circuit 7 of at least 10 to 70 times per second, taking into consideration the characteristics of the very high heterogeneity of the concrete, and the fact that the concrete is usually distributed with an alternative pump, with consequent irregularities in its feeding movement. Therefore, in the correlation circuits, an average operation is carried out, which eliminates noise from the noise signals before sending them to the processor 10 of the reception circuit. The processor then joins the real and imaginary parts of the signals again, also performing a filtering operation, and provides it to extract from the velocity values (each with its own sign) the desired profile, which is then evidenced in a screen, as illustrated by way of example in Figure 4 (where, indicates the velocity -order- and d .. represents - abscissa - the diameter of the pipe C, through which the concrete is caused to flow). Once the velocity values have been recovered in each section, with the same processor 10 it is also possible to determine, by means of electronic computing processes, the flow velocity (as integral velocity over the section area), the viscosity (as a derivative). of velocity in space) and the particle size (through a statistical analysis of a velocity profile pack) of the concrete flowing in the C pipe. The possibility - to determine all these physical quantities finally allows to guarantee a certification to the feed of concrete through the pipe C equipped with the detection device of the present invention.

Claims (7)

1. A device for detecting the velocity profile of concrete inside a pipe (C) with a radial symmetry through which the concrete is caused to flow -of the type comprising an acoustic probe means, apt to send. through the pipe (C), and the concrete that flows in it, a supersonic ray inclined with respect to the axis of the pipe, and to receive a supersonic ray altered in response, as well as an electronic circuit, apt to analyze the signals sent by the probe means and to obtain from them a diagram showing the separate profile of the concrete - characterized in that the supersonic ray probe has a frequency comprised between 20 and 500 kHz, and wherein the electronic circuit comprises a means for process the signals sent by the probe means, and indicate the speed, with an update frequency of 10 to 70 times per second, and a means to eliminate from the signals their components derived from the velocity of propagation in the concrete, and obtains a measurement of the speed along the acoustic axis, which is not related and has its own sign.

2. The device according to claim 1, characterized in that the velocity measurements are shown as a velocity profile.

3. The device according to claim 1, characterized in that the flow velocity is measured as an integral velocity over the section area.

4. The device according to claim 1, characterized in that the viscosity measurements are obtained as first derivatives of the velocity in space.

5. The device according to claim 1, characterized in that the granulometry and the density measurements are obtained through a statistical analysis of a speed profile package.

6. The device according to claims 1 to 5, characterized in that probe means are adopted, in which the transmitting and receiving probes coincide.

7. The device according to claims 1 to 6, characterized in that the probe means are applied on the pipe (C) so that the supersonic beam, of which use is made, is inclined at 15 ° to 75 ° with respect to the axis of the pipe.