DEVICE TO DETECT THE SPEED PROFILE OF CONCRETE FLOWING INTO A PIPELINE

Abstract: A device to detect the speed profile of concrete flowing through a pipeline with radial symmetry comprises acoustical probe means, apt to send through said pipeline and the concrete a supersonic ray inclined in respect of the pipeline axis and to receive a disturbed supersonic ray in response, as well as an electronic circuit apt to analyse the signals sent by said probe means and obtain therefrom a diagram showing the speed profile of the concrete. According to the invention, said probe means make use of a supersonic ray of frequency between 20 and 500 KHz, and said electronic circuit processes the signals sent by the probe means, indicating the speed, with an updating frequency from 10 to 70 times per second and deprives said signals from their components derived from the propagation rate in the concrete, to obtain a measurement of the speed along the acoustical axis, which is not relative and has its own sign.

Description: "DEVICE TO DETECT THE SPEED PROFILE OF CONCRETE FLOWING INTO A PIPELINE" ===o0o=== The present invention concerns a device to detect the speed profile of concrete inside a pipeline with radial symmetry through which said concrete is caused to flow. There are already known to be processes and devices to detect the speed 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 - as, for example, blood - the dishomogeneities of which have dimensions of several magnitude orders below the size of the ducts through which they flow, which are of small or very small dimensions. Whereas, the problem had never been faced to detect the speed pro¬ file of fluids having a high density and a very high viscosity, such as concrete, the dishomogeneities of which have dimensions of the same mag¬ nitude order as those of the ducts - always pipelines of wide diameter - through which they flow. The present invention faces and solves this problem by supplying a device to detect the speed profile of concrete inside a pipeline with ra¬ dial symmetry, through which the concrete is caused to flow. Said device - of the type comprising acoustical probe means, apt to send through said pipeline, and the concrete flowing therein, a supersonic ray inclined in respect of the pipeline axis, and to receive a disturbed supersonic ray in response, as well as an electronic circuit, apt to analyse the signals sent by said probe means and obtain therefrom a diagram showing the speed profile of the concrete - is characterized in that, said probe means make use of a supersonic ray of frequency between 20 and 500 KHz, and in that said electronic circuit processes the signals sent by the probe means, indicating the speed, with an updating frequency from 10 to 70 times per second, and deprives said signals from their components derived from the propagation rate in the concrete, to obtain a measurement of the speed along the acoustical axis, which is not relative and has its own sign. Said detection device allows to display said speed measurements as a speed profile. Moreover, it allows measuring the flow rate, as a speed integral on the section area, and it also allows viscosity measurements as first derivatives of the speed in the space, as well as granulometry and density measurements through a statistical analysis of a packet of speed profiles. For economical reasons and to simplify construction and operation it is usually convenient to adopt, in the detection device according to the invention, probe means wherein the transmitting and receiving probes coincide. Suitably, such probe means shall be applied on said pipeline so that the supersonic ray, of which use is made, is inclined by 15° to 75° in respect of the pipeline axis. The invention will now be described in further detail with referen¬ ce to the accompanying drawings, which illustrate a preferred embodiment of the detection device defined heretofore, and in which: Fig. 1 represents a block diagram of the detection device according to the invention; Figs. 2 and 2A are diagrams illustrating, in two orthogonal sections, the application of the acoustical probe, forming part of the detection device of fig. 1, to a pipeline for concrete distribution; Fig. 3 illustrates the propagation, in said pipeline, of the super¬ sonic ray emitted by said probe into the various concrete components crossed by said ray; and Fig. 4 represents an example of speed profile of the concrete caused to flow into a distribution pipeline, such as it is displayed in the detection device according to the invention. With reference to the drawings, the detection device according to the invention is of the type making use of a supersonic ray r_ (figs. 3 and 2), of frequency between 20 and 500 KHz, sent across the concrete flowing through a pipeline C; said device operates by detecting the disturbance appearing on the ray _r_|_ of response (figs. 1 and 2A) , in function of the irregularities deriving from the heterogeneous composi¬ tion of the concrete, which influence the propagation of said ray r' . The detection device is applied on the pipeline C so that the su¬ personic ray, of which use is made, is inclined by 15° to 75° in respect of the axis of said pipeline (fig. 2). As shown in fig. 1 , said device consists of a transmitting probe 1 , which sends the supersonic ray _r suitably inclined towards the pipeline C through which the concrete flows, so as to cross this latter and be dis¬ turbed and propagated thereby, of a receiving probe 2, which collects the disturbed ray _r emerging from the pipeline C, and of a reception circuit to which are fed signals produced by the receiving probe 2. The receiving probe 2 is positioned on the same plane as the transmitting probe 1 , for¬ ming any angle OC therewith (see fig. 2A), and it may also coincide - it is preferably caused to coincide (as shown in fig. 2), with advantages as far as costs and simplicity of the device - with the transmitting probe. In the reception circuit, the signals sent by the receiving probe 2 are amplified by a logarithmic amplifier 3 > with a gain which varies according to time, that is, to the distances of the propagation points from which the signals are issued. The amplified signals are sent to a wattless decomposition circuit 4: this is a simple circuit (preferably, a very cheap RC unit) which re¬ covers the real part and the imaginary part of the signals, sending them separately to the shunting circuits 5 and 6, which are controlled by a sampling circuit 7- In the shunting circuits 5 and 6 (preferably, two simple and economic digital shunts) the real and imaginary parts of the signals are shunted. The shunting time base of the shunts 5 and 6 is chosen so that, to each instant there corresponds a position in space of the echo-signal advancing in the pipeline C: one thereby analyses, so as to be able to obtain the desired profile, the concrete mass moving into the pipeline C, section by section, along the axis of the supersonic ray and at preset distances from the sampling interval. Fig. 2 illustrates, by way of example, a series of sections s. The signal issued by the shunting circuit 5 is multiplied by the signal issued by the shunting circuit 6 and is sent to the correlator 9, while the signal issued by the shunting circuit 6 is changed of sign, is multiplied by the signal issued by the shunting circuit 5 and is then sent to the correlator 8. The correlators 8 and 9 are controlled by the sampling circuit 7- In said circuits, the real and imaginary parts of the signals of each section are correlated so that it may be possible to recover the speed, along the axis of the supersonic ray, of the particles in each section. By identifying the walls of the pipeline as the sections which, by definition, are speedless, it is possible to render the measu¬ rement independent from the speed of propagation in the concrete (the particular concrete in the special conditions in which it is while flow¬ ing into the pipeline C) and from the refraction angle of the supersonic ray in the pipeline wall-concrete passage (see fig. 3). and to obtain an absolute measurement (and not a relative one, as it happened in the known detection devices used in the medical and biological field) of the speed in each section (each measurement with its own sign). The processing should occur with an updating frequency by the sampling circuit 7 of at least 10 to 70 times per second, taking into account the characteristics of very high dishomogeneity of the concrete, and the fact that concrete is usually distributed with an alternative pump, with consequent irregu¬ larities in its feeding motion. In the correlation circuits a mean operation is thus carried out. allowing to clear from the noise the single signals before sending them to the processor 10 of the reception circuit. Said processor then joins again the real and imaginary parts of the signals, performing also a filtering operation, and it provides to draw from the speed values (each with its own sign) the desired profile, which is thus evidenced onto a display, as illustrated by way of example in fig. 4 (where v ^ indicates the speed - ordinates - and cl represents - abscissae - the diamater of the pipeline C, through which the concrete is caused to flow). Once having recovered the speed values in each section, with the same processor 10 it is also possible to determine, through ordinary electronic computation processes, the flow rate (as speed integral on the section area), the viscosity (as derivative of the speed in the space), and the granulometry (by a statistical analysis of a packet of speed profiles) of the concrete flowing into the pipeline C. The possibility to determine all these physical quantities finally allows to guarantee a certification to the concrete fed through a pipe¬ line C equipped with the detection device of the present invention.

Claims: CLAIMS 1 ) Device to detect the speed profile of concrete inside a pipeline with radial symmetry through which the concrete is caused to flow - of the type comprising acoustical probe means, apt to send through said pipeline, and the concrete flowing therein, a supersonic ray inclined in respect of the pipeline axis, and to receive a disturbed supersonic ray in response, as well as an electronic circuit, apt to analyse the signals sent by said probe means and obtain therefrom a diagram showing the speed profile of the concrete - characterized in that, said probe means make use of a supersonic ray of frequency between 20 and 500 KHz, and in that said electronic circuit processes the signals sent by the probe means, indicating the speed, with an updating frequency from 10 to 70 times per second, and deprives said signals from their components derived from the propagation rate in the concrete, to obtain a measurement of the speed along the acoustical axis, which is not relative and has its own sign. 2) Device as in claim 1), wherein said speed measurements are displayed as a speed profile. 3) Device as in claims 1 ) and 2) , wherein the flow rate is measured as a speed integral on the section area. 4) Device as in claims l) to 3) > wherein viscosity measurements are obtained as first derivatives of the speed in the space. 5) Device as in claims 1) to 4), wherein granulometry and density measurements are obtained through a statistical analysis of a packet of speed profiles. 6) Device as in claims l) to 5), wherein probe means are adopted, in which the transmitting and receiving probes coincide. 7) Device as in claims l) to 6), wherein said probe means are ap¬ plied on said pipeline so that the supersonic ray, of which use is made, is inclined by 15° to 75° in respect of the pipeline axis. 8) Device as in claims 1) to 7) > wherein a certification of the concrete fed through said pipeline is obtained.

Inventors: MORETTI GIORGIO, VENTURINO GIANFRANCO, MORETTI, GIORGIO, VENTURINO, GIANFRANCO
Applicants: CIFA SPA, MORETTI GIORGIO, VENTURINO GIANFRANCO, CIFA S.P.A., MORETTI, GIORGIO, VENTURINO, GIANFRANCO
Application year: 1997
Main classification: G01N29
IPC codes: G01N29