DE2117692A1 - Measuring device - Google Patents

Description

DR. E. WIEGAND DIPL-ING. W. NIEMANN

DR. M. KÖHLER DIPL-ING. C. GERNHARDT 2117692

MDNCHEN HAMBURG TELEPHONE: 395314 '2000 HAMBURG 50, "ft *" TELEGRAMS. KARPATENT KONIGSTRASSE 28 ^V

W. 24 686/71 8 / B

Pierre Marie Marcel Penet, Creteil (France)

Measuring device.

The invention relates primarily to industrial flow meters, which are used to measure the flow rate a medium flowing through a line to measure, and for this purpose a screw provided with inclined wings and set in rotation by the medium and means for measuring the speed of rotation of the screw. The invention also relates to a measuring device with thumb screw, which serves to increase the viscosity to measure a product flowing through a pipe industrially.

In a known industrial flow meter, the wing screw is one in the line in the longitudinal direction extending axis freely rotatable so that it rotates at a rotational speed that corresponds to the throughput of the medium »between certain limits of this throughput rate and the viscosity of the medium, practically proportional is. The rate of rotation of the wing screw of a conventional flow meter therefore provides a fairly accurate one Measure of the throughput, but only if this is between certain limits and if the viscosity of the Medium comes close to that for which the flow meter has been developed and calibrated. No existing through

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Set quantity meter with screw permitted at any moment determine whether its work is correct or not, and still less does it enable an indication of its accuracy to get the measurement of the throughput rate because of the properties and in particular the viscosity of products flowing through an industrial line differs from one another May randomly change time to another.

No flow meter provides an indication of the viscosity of the product whose flow rate is being measured,

The invention aims to provide improvements, on the one hand the monitoring and control of the work enable a flow rate meter with wing screw and on the other hand provide a correction that allows the To use flow meter for measuring the flow rates of media of high or variable viscosity. These Improvements also make it possible to realize a throughput meter that measures the viscosity of the medium and at the same time indicating its flow rate, or to realize a measuring device with screw that in series can be arranged with a flow meter and provides an approximate measure of the viscosity.

According to the invention, the screw provided with inclined wings, which is arranged freely rotatable after the screw of a conventional flow meter, is assigned a freely rotatably mounted auxiliary rotor which is arranged coaxially to the screw and downstream of it and with straight lines, ie in through the common axis through planes lying wings is provided. A device is provided which measures the rotational speed ω ,, of the auxiliary rotor and compares and / or combines it with the rotational speed ω of the screw.

In one embodiment of the invention, the measure of the throughput rate is supplied in a known manner by the speed of rotation co of the screw, and the changes in the ratio co, / co, preferably by means of a calculator

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is determined, the plague enable whether working the flow meter is correct or faulty.

In another embodiment of the invention, the measure of the throughput rate is derived from the sum of the absolute values the rotational speeds ω and ω, which, if necessary, with Correction coefficients are provided, which allows, with an accuracy sufficient for industrial needs measure the flow rate of a very viscous medium or a medium of variable viscosity. At this Embodiment allows the ratio cj </ cj also, detect that the flow meter is not working properly.

An increase in the viscosity of a medium flowing with a given flow rate causes a slowing down of the wing screw and an acceleration of the auxiliary rotor, so that the comparison of co and cj _f gives an indication of the viscosity and ^ of it can even give an approximate value.

The invention is explained below with reference to the drawing, for example.

Pig. 1 is a schematic axial sectional view of a

Flow rate meter according to the invention. Fig. 2 is a developed one held on an enlarged scale View of the profile of a wing of the screw at the level II-II of Fig. 1, and it shows the diagram of the velocities at the exit of this profile.

Fig. 3 is a diagram illustrating the operation of the screw.
Fig. 4 is a circuit diagram of a circuit for

Messen de? and evaluating the rotational speeds the screw and the auxiliary rotor. Fig. 5 is a circuit diagram similar to Fig. 4 showing the

represents another embodiment. Fig. 6 shows the general course of a curve which

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to determine the viscosity.

The flow rate meter shown schematically in FIG. 1 according to the invention has a conventional wing screw 1 and an auxiliary rotor 2, which are arranged coaxially in a line section 3 to the flow rate to measure a medium, which through the line in Rieh-. direction of arrow F flows through it.

The screw 1 has inclined wings 4 and a hub 5 which is freely rotatably arranged in the usual way by means of ball bearings (not shown) on a rod 6 which is supported in a floating arrangement by three radially directed arms 7 offset from one another by 120 ° , which are connected to an annular piece 8 which has a front cylindrical part 8a which is inserted into the line section 3 and fastened in it by means not shown in such a way that the axis of rotation of the screw 1 coincides with the axis XX ^{1 of} the line section 3 . The ring piece 8 has, downstream of its cylindrical cable 8a, a converging adapter part .8b which merges into a cylindrical wall 8c which is provided with an outer flange 8d at its downstream end.

There is a second similar ring piece 9 is provided, which has a cylindrical wall 9a, the upstream End is provided with an outer flange 9b and downstream merges into a divergent recovery part 9c, which is connected to three radial arms 10, which a rod 11 overhung on which the hub 12 of the auxiliary rotor 2 is arranged freely rotatable by means of ball bearings (not shown). The ring piece 9 is pushed into the line section 3 and attached to it by means not shown in such a way that the axis of rotation of the auxiliary srotors 2 with the axis X-X * of the line section 3 coincides · The collar 9d of the ring piece 8 and the collar 9b of the ring piece 9 are against one another by means of echematically indicated by dashed lines 13 Bolt fastened.

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It should be noted that the ball bearings, not shown have negligible friction and therefore practically no resistance to the rotation of screw 1 and rotor 2 oppose. The screw 1 and the rotor 2 are thus arranged to be freely rotatable, i.e. their rotation is practical is uninhibited.

The hub 12 of the auxiliary rotor 2 carries wings 14 which, as from Pig. 1 can be seen, lie in.radiale i-planes which pass through the axis XX ¹ . The rod 6 carrying the screw 1 extends downstream of the screw almost to the hub 12 of the auxiliary rotor 2, and the rod 6 and the rod 11 carrying the auxiliary rotor 2 are thickened between the hubs 5 and 12 and on both sides of them, so that a cylindrical body 15 is formed around the axis XX ¹ , which ends upstream and downstream in profiled pointed arch parts 16 or 16a. The screw 1 and the auxiliary rotor 2 are arranged in this way one behind the other in an annular channel 17, which between the cylindrical outer surface of the body 15 and the cylindrical inner surface of the walls 6c and 9a downstream of the _; converging part 8b and upstream of the diverging part 9c.

The medium passing through the line section 3 generates a flow consisting of parallel streams in each channel 17, which acts on the inclined wings 4 of the screw 1 and thus sets the screw in rotation. It is known that the speed of rotation u) the screw of the flow rate Qj of the medium, between certain limits of the flow rate] and the viscosity of the medium, is practically proportional ·! The screw exerts a restraint on the medium flow

action that their downstream of the screw rotation in the reverse sighting to the rotation of the screw issued · The 'set in rotation medium acts on the wing 14 of the auxiliary rotor 2 eifc and offset this _f in rotation at a speed ««

The speed of rotation ω of the screw 1 and the

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speed cj _{4 of} the auxiliary rotor 2 are measured by means of two ultrasonic devices 18 and 19, respectively, which are comparable to those shown in French patent application No. 70 09 886 of March 19, 1970, and for this reason it seems superfluous to use them to be rubbed here in detail.

The hub 5 of the screw 1 is provided with flats 20 which, during the rotation of the screw, successively reflect an ultrasonic radiation emanating from a transmitter 18a of the device 18 towards a receiver 18b, which is thereby excited in a rhythm which is proportional to the rotational speed cj of the screw is. The device 19 likewise has a receiver 19b _{which is excited in a lihyümus proportional to the rotational speed Cj 1 of} the hotor 2 by an ultrasonic radiation which emanates from a transmitter 19a and. is reflected by flats 21 of the hub 12 of the rotor 2 against the receiver 19b.

The operation of the screw 1 can be understood from FIG. 2, which shows the profile 4a of a wing 4 at a distance r (FIG. 1) from the axis XX ¹ and the diagram of the (speeds at the exit of the profile. 4a The arrow la drawn in 2 indicates the direction of rotation of the screw 1. The relative speed W of the medium at the outlet of the profile 4a is inclined to the axis XX * at the same angle (S as the profile 4a. The absolute speed V of the medium is the resultant of the relative speed W and the tangential speed U of the profile 4a. This absolute speed V has an axial component Vd (referred to as throughput speed) and a tangential component Vt which represents the tangential speed of the flow at the outlet of the profile 4a.

If with U, Vt and Vd the magnitudes of the velocities U and Vt, Vd are designated, then the diagram of the velocities shows that these quantities are given by the relationship

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U + Vt - Vd.tgf »(1)

are linked.

Since U is equal to CJ.r and Vd is proportional to the flow rate Q, there is a relationship at the height of the profile 4a

ω.r + Vt = k.Q.tgß (2)

in which k represents a constant, a relationship equal Shape exists along the entire length of each wing of the screw to the circumference of the hub. It is therefore to be understood that the speed of rotation co of the screw with the flow rate Q by a -relation of the form

CJ = AQ - B.Vt _m (3)

is linked, in which A and B are constants and Vt _{m represents} the mean tangential velocity of the medium at the exit of the screw

This latter relationship shows that the rotational speed ui of the screw is not exactly proportional to the flow rate Q and only provides a fairly accurate measure of it if the mean tangential speed Vt is sufficiently small with respect to the flow rate, and this makes the application of the known throughput flow meter, as will be explained below with reference to FIG.

Fig. 3, in which the diagram of the speeds reproduced on a larger scale in dashed lines illustrates the operation of the screw at the profile 4a when the flow rate Q varies. The throughput speed Vd, which is proportional to the throughput Q, is plotted on a straight line 0-X, and the relative speed W is plotted on a straight line 0-y, which is inclined to the straight line O-x at the angle ^. It a curve So-S is drawn in, which is the geometric location of a point M »and the end of the vector 0-M represents the Speed V when the throughput Q varies, where-

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when the viscosity of the medium is constant. The straight lines 0-L and 0-N limit between them the usable part 'of this curve, for which the rotational speed ω is a measure that delivers the flow rate with the required accuracy (for example with about ^ 1 $ for a conventional flow rate meter or with about * 0.17k for a very accurate flow rate meter). Vf'if the throughput Q increases from zero, the diagram point M moves first on the straight line 0-y up to the point So, then on the curve So-S up to the point To and finally on the usable part To-S of this curve.

Since at the beginning the drive torque (which is applied to the screw by the medium) is smaller than that which is resisting it The moment the screw is, the screw actually remains immobile. From the point So onwards the drive torque exceeds the moment resisting it, and the screw begins to turn, however, is from point So to point So the tangential speed Vt with reference to the throughput speed Vd is large, and the speed of rotation of the screw only provides an insufficiently accurate measure of the Throughput Q, i.e. the device is said to be "out of tolerance". Only if the point Me is on the part To-S of the curve moves, the measurement is carried out with the required accuracy.

If the kinematic viscosity of the medium increases from • ^ to * 9 ₄ , y _s etc., the viscous heat on the screw also increases (which creates the aforementioned resisting moment), so that the curve of the geometrical location of the diagram point M their shape changes, as shown by dashed lines, the point So shifts on the straight line 0-y to S1, S2, etc., and the point To shifts on the straight line 0-1 to Tl, Ϊ2, etc. If the point M is, for example, between S1 and Tl or between S2 and T2, the speed of rotation of the screw delivers only a very imprecise measure of the throughput quantity

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required accuracy (i.e. the smallest value of the throughput quantity that can be measured with this accuracy can) increases with viscosity, and on the other hand that, if the viscosity of the medium changes unexpectedly, the speed of rotation of the screw gives an inaccurate reading could deliver the throughput without this being apparent.

In addition, the screw can be subject to work defects, for example through a change in the mechanical Friction in a bearing or deformation of the plugs due to wear and tear caused by erosion. These work deficiencies lead to measurement errors caused by the knowledge of the speed of rotation of the screw cannot be determined.

The invention makes it possible to eliminate these disadvantages due to the arrangement of the auxiliary rotor 2. The speed of rotation OJ _{1 of} the rotor is in fact essentially proportional to the mean tangential speed Vt, regardless of how great the flow rate and the viscosity of the medium are; the viscous friction is only longitudinal
Rotation de

to understand,
Position of the D:

stresses that have no influence on the rotor 2.

From i: .g. 3 it can be seen that Vt is exactly proportional to U would be irurd if the part To-S of the curve of the geometrical Locations of the point M would be linear, so üia is too that the change in the ratio w ^ / do the agrammpunktes M on the curve So-S indicates. if

this ratio remains essentially constant (in the required {tolerance of * 1 $ or * 0.1? «), then one would know that the point M is between the straight lines 0-L and 0-N, and thus »that the screw 1 is working properly.

A ^ embodiment of the invention, in which the speed of rotation cj of screw 1 is used to measure the permeation rate, and the ratio cj «/ w is used to

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is used to control the working of the screw, is shown below with the aid of the circuit diagram according to FIG. 4 described.

In Fig. 4, the screw 1 and the auxiliary rotor 2, the are arranged in the line section 3 through which a medium flows in the direction of arrow P, as well as the ultrasonic devices 18 and 19 shown schematically.

The ultrasonic radiation emanating from the transmitter 18a and from the flats on the hub of the screw 1 during their rotation is reflected by the iümpfanger 18b recorded, which a signal shown schematically at 18o of high frequency (the frequency of the ultrasonic radiation) supplies that is proportional to the rotational speed co the Screw is modulated. This signal is sent to a demudulation group 22 is applied, which converts it into a signal 18d, whose frequency f is proportional to the speed of rotation co of the screw is· - . .

A frequency-to-analog converter 23 converts the signal 18d into an analog signal proportional to ω (for example a voltage), which is applied to a .anzeiger 24, whose The pointer moves proportionally to approx. The device can be calibrated in a known manner in such a way that dejss the indicator 24 shows the throughput Q of the medium directly, indicates. The signal 18d is also sent to a "divider" designated circuit 25 is applied, which is the quotient of the frequency f of this signal and the constants of the device (i.e. for example the volume of the medium whose flow through the screw 4 Ie screw by one turn rotates) and generates an output signal proportional to this quotient, which is sent to a totalizer 26 is applied so that it indicates the volume JQdt which flows through the device.

The receiver 19b of the other ultrasound device 19 delivers a signal 19o that is in a demudulation circuit 27 is demodulated to generate a signal 19d whose frequency

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quenz £ 1 of the rotational speed cj _{4 of} the rotor 2 is proportional.

The signals 18d and 19d are converted by two frequency-to-analog converters 28 and 29, respectively, into analog signals which are proportional to the rotational speeds “o and Cj ₄ ”, of which the ratio ca, / gj is formed in a circuit 30. The cj </ co signal emerging from this circuit 30 serves to excite a further indicator 31 from which the value of the ratio cu «/ ej can be read off directly. This indicator 31 can be completed by a visual or audible alarm providing device which becomes effective when the ratio ω * / ω exceeds a value shown on an instruction device 31b.

In this way, as soon as the flow meter works out of tolerance, this condition is triggered by the alarm device brought to the attention immediately. This arrangement is very advantageous, especially in the case where the Display of the flow meter serve as the basis for a booking *

In the case in which the viscosity of the medium is high or variable, the rotational speed cJ * of the auxiliary rotor 2 in combination with the speed of rotation co of the screw 1 can be used to determine the throughput Q measure su. In fact, this is essentially a linear function of ω and ω «·

As can be seen from Fig. 1, the walls of the annular channel 17 are cylindrical, so that in this channel a Flow from essentially parallel streams arises, at least when the medium is a non-compressible liquid is. Therefore, if the auxiliary rotor 2 is sufficiently close to the screw 1, it can be assumed (Fig. 2), that the medium, which is at the distance r from the axis X-X * lying wing profile 4a of the screw with the speed V leaves the ΓIUgel 14 of the auxiliary rotor 2 in the same Distance r from the axis will reach.

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The magnitude Vt of the tangential velocity Vt is therefore equal to w _for. It follows from this that (2) can be written for the above-mentioned relationship

(oj + Cu ₄ ) .r = kQtgß (4) and that the relation (4) changes into

co + CJi = A.Q '(5)

Under these conditions, the sum co + Co _{1 of} the absolute values of the speeds of rotation of the screw and the auxiliary rotor is thus proportional to the flow rate Q and can provide an exact measure of this flow rate, even if it is very small (theoretically of a flow rate of zero), even if the Viscosity of the medium is large and even if this viscosity changes randomly.

If for any reason (for example if the medium is a gas) the flow in the channel 17 can no longer be regarded as a flow of parallel streams, the medium leaving the profile 4a (Fig. 2) with the velocity V, reach the blades 14 of the auxiliary rotor 2 at a distance different from r, but it can be allowed that the magnitude _{Vt of the tangential velocity is proportional to cj 4} v , so that the drawing between o », cj _f and Q would pass into

Cj + &, Cü ₄ β AQ (6)

where the correction coefficient a is a constant.

It is this relationship that provides an accurate measure of the throughput rate Q delivers.

If the first case exists - relationship (5) -..> Is one, the circuit arrangement according to Figure 5 is used which differs from that of FIG 4 in that the flow rate Q cj of the sum + Co ₁ the rotational speeds of the screw 1 and of the auxiliary rotor 2 is supplied, the elements of this arrangement which have the same task as those of the arrangement according to FIG.

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Chen reference numerals are provided.

The signals 18d and 19d emanating from the demodulation circuits 22 and 27, respectively, are applied to an adder 32 which operates with anticoincidence and which supplies a signal 32 ^ a whose frequency f3 is proportional to GJ + Oj ^. This signal 32a is converted by the Yfandler 23 into an analog signal which is proportional to co + W ₄ , so that the pointer of the indicator 24 is deflected _{proportionally to cü + Cj 1;} the indicator can be calibrated in such a way that it shows the flow rate Q directly. indicates. The signal 32a is also applied to the divider circuit 25 so that the totalizer 26 displays the volume JQdt which has flowed through the line.

If the second case - relation (6) - is present, the correction coefficient a of relation (6) is first determined by calibrating the flow rate meter. For this purpose, note the values of co and OJ ₁ , the various values of the flow rate Q which makes it possible to determine the constant coefficient a by which gj <is to be multiplied so that the sum CJ + a. <y <is proportional to Q. The simple adder 32, which works with anticoincidence, is then replaced by a more complex circuit known per se, which is suitable _{for carrying out the operation ω + a.CJ 4.}

As in the Pail of the arrangement according to Pig. 4 shows the indicator 31 gives the value of the ratio gj * / cj, and it makes one Alarm Vorriphtung effective if this ratio changes abnormally, for example due to a bearing damage or a Erosion dek »screw.

It is very useful to be able to at least approximately measure the viscosity of a liquid product flowing through an industrial pipe. As already indicated above, the comparison of Q undoi <gives an indication of the viscosity of the product, and it can even give an approximate value of it. From Pig. 3 it can be seen that the tangential speed Vt of a profile 4a (Pig.2)

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leaving product of viscosity N through the range H-M is measured that the throughput speed Vd is measured through the distance 0-M and that the tangential speed U of profile 4a is measured through the segment K-M, where the diagram point M lies on the curve So-To-S, which corresponds to the viscosity S.

The product of the viscosity ^ f ,, which leaves the profile 4a at the same throughput speed Vd will have a tangential speed measured by the distance HM ^ and the tangential speed of the profile 4a is given by the distance KMj. measured, the diagram point M- ^ lying on the curve that corresponds to the viscosity V ^. As before, it can be assumed that the tangential speed of the profile 4a is proportional to Cü and that the tangential speed of the product is proportional to ^. It follows that knowing cj and ω ₄ enables the viscosity value of the product to be determined.

The value of the viscosity as a puncture of Cj undo * could, at least theoretically, be calculated by means of the formulas and methods of the mechanics of media.However, the formulas which allow the kinematic viscosity V to be calculated as a function of cj and ω _4, extremely complicated, so that the calculations would be very tedious. The value of the viscosity is therefore preferably determined with the aid of a diagram which is recorded from a calibration of the device, it is easy to record such a diagram by allowing products of known viscosities with different flow rates to flow through in the line section 3 and for each test the values of cu, cj _A , the viscosity "\) and, if necessary, the throughput quantity Q are noted.

Pig. 6 shows the general course of one of the pigs as an example. 3 analog diagram obtained by that the throughput Q is plotted on the abscissa

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and on the ordinate the sum a + W / is plotted, the respective value of which is represented by the line 33, us it can be seen that the value of q + cJf allows the line H'-K 'to be arranged on the diagram, and that ( for example) the value of cj, which determines the length of the part of this line between the point H ¹ and the point of intersection M 'or M ¹ π or M'p or M ¹ , with one of the lines V or V _{4 >> 8} > V ₅ , which indicates the value of the viscosity.

Obviously, the diagram can also be plotted in another form. In particular, commit can be multiplied by the correction coefficient a of the relation (6) given above, ie it can be the lengths, such as the length H ^! -M ', the value ao <and the lengths as the length H'-K' are given the value <y. In practice, it is preferable to produce a diagram with aligned points, which allows more convenient evaluation.

It should be noted that, for obvious reasons, the flow rate meters with wing screws are generally designed in such a way that changes in the viscosity of the product affect the speed of rotation of the screw as little as possible. With a well-designed flow rate meter, the lines "V, V _{,, V a} ," V ^, of FIG Deliver throughput with the required accuracy. The measurement of viscosity will therefore not be very accurate. In the meantime, the person skilled in the art knows that it is possible to increase the viscous heat of a screw such as screw 1, for example by machining its surface and / or its profile less carefully (ie increasing the roughness of the surface and / or the profile is given a less hydrodynamic shape) so that its speed of rotation is very sensitive to viscosity. If it is assumed that, as already mentioned above, the rotational speed of the auxiliary rotor 2 for the

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Viscosity is insensitive, then a device similar to that of FIG. 1 and having a screw 1, the rotation of which is very sensitive to viscosity, will provide a measure of viscosity with a fairly good approximation, and indeed they will Lines V, V <, V ^, V ₃ of Fig. 6 are quite far apart,

The invention therefore makes it possible, on the one hand, to realize a precisely working flow rate meter that has a Provides indication of the viscosity of a medium, and on the other hand to realize a measuring device that a measure of the viscosity of a pipe flowing through a pipe, which is sufficiently precise for industrial use Medium supplies. JSine such measuring device can be in series be arranged with a precisely working flow meter.

It should be noted that the embodiments described above are only examples and that they are within the scope of FIG Invention can be modified, in particular by replacing technical equivalents.-In particular, could take place to calculate the ratio «0. / w by means of an analog device, which, due to its nature, will not be very precise, the ratio cj / cj ^ which is the opposite of the above ratio can be calculated with great accuracy with the aid of a known numerical circuit, which is obtained by comparing the frequencies f and f-i of signals 18d and 19d, respectively, operate.

Furthermore, a puncture size _{of <υ and cj 4f,} which differs from their ratio, could also be used for the comparison of cj and ca, in order to control the accuracy of the measurement of the throughput quantity. The exact measure of the throughput rate could be provided by a linear function of Cj and Oj ₁ , which has a form different from the relationships (5) and (6), for example by the sum of the absolute values of cj and w *, which is marked with Correction coefficients are provided, of the form b.üJ + c.cj ^.

The speeds of rotation of the screw and the Hilfero-

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tors can be measured by any means
will. The processes, which from these rotational speeds, the throughput rate, the puncture size of ο and Q ^,
which serve to control the accuracy of the measurement and allow the viscosity to be determined can be brought about by any suitable means, in particular by calculations or with the aid of diagrams.The scope of the invention is also not departed from if the viscosity is determined from α and _{co 4} by means of a computing device is determined.

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Claims (10)

Claims I 1.1 Measuring device, which is to be arranged in a line through which a medium flow passes, characterized by the combination of a screw provided with inclined wings, which is arranged freely rotatable about an axis running in the longitudinal direction of the line, so that it rotates at a rotational speed can rotate, which is the flow rate of the flow, between certain limits of this flow rate and the viscosity of the medium, is practically proportional, a coaxial to the screw and downstream of it freely rotatably arranged rotor which is provided with vanes that are essentially in by the common axis are through planes, and devices for measuring the speed of rotation ο of the screw and the speed of rotation O _{1 of} the rotor. ^l 2. Measuring device according to claim 1 for measuring the throughput of the flow, characterized by a device which compares the rotational speed cj _{4 of} the rotor with the rotational speed cj of the screw in order to control the accuracy of the measurement of the throughput. 3. Measuring device according to claim 2, characterized in that the accuracy of the measurement of the throughput rate is determined by the value of the ratio cji / ω . 4. Measuring device according to one of claims 1 to 3, characterized in that a warning signal device responding to the ratio CJ * / u> is provided, which comes into effect when the ratio ^ ₁ / cj exceeds a predetermined value. 5 · Measuring device according to one of: Claims 1 to 4t thereby marked that a device is provided, which measures the throughput rate according to the sum of the absolute values of <ü and αλ, which is possibly by means of a calibration certain correction coefficients are provided * 6. Measuring device according to one of claims 1 to 5 »da- 109845/1195 characterized by »that a facility is provided, which is the speed of rotation ^ J of the screw and the speed of rotation Cordes Rotors compares or combines them in order to enable the viscosity of the medium for example to be determined by means of a diagram produced by a calibration. 7 · Device for measuring the viscosity of a medium flowing through a line, characterized by the combination of a screw provided with inclined wings around a longitudinally extending screw in the conduit Axis is freely rotatably arranged, a rotor which is coaxial with the screw and freely rotatable downstream of it, which is provided with wings which lie essentially in planes passing through the common axis, Devices for measuring the speed of rotation <0 of the screw and the speed of rotation cj-t of the rotor and a device to determine the viscosity of the medium from the measured values of the rotational speeds ο and ω *. 8. The device according to claim 7, characterized in that the surface condition and / or the shape of the screw are chosen in such a way that the viscosity of the medium strongly influences the speed of rotation of the screw. 9. Device according to claim 7 or 8, characterized in that the device for determining the viscosity from the measured values of the rotational speeds to and CJ _{1 has} a curve diagram produced by calibrating the device. 10. A method for determining the approximate value of the viscosity of a medium flowing through a line, characterized in that the speed of rotation of a screw caused by the medium flow in the manner of Screw of a conventional flow meter is set in rotation, and the speed of rotation of a downstream of the screw and coaxially to it freely rotatably arranged rotor, which with essentially in through the common axis 109845/1195 vanes lying through planes are provided, and the measured values of the rotational speeds of the screw and the rotor, which were previously by means of currents are calibrated by media of known viscosities, can be used to determine the viscosity, for example by means of a Calculate curve diagram. 109845/1195