US3609316A - Composite mixture batching - Google Patents

Composite mixture batching Download PDF

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Publication number
US3609316A
US3609316A US640571A US3609316DA US3609316A US 3609316 A US3609316 A US 3609316A US 640571 A US640571 A US 640571A US 3609316D A US3609316D A US 3609316DA US 3609316 A US3609316 A US 3609316A
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analogue
amount
analogue value
components
water
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Noel M H Brosset
Johan Winther
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Pedershaab Maskinfabrik AS
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Pedershaab Maskinfabrik AS
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    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06G—ANALOGUE COMPUTERS
    • G06G7/00—Devices in which the computing operation is performed by varying electric or magnetic quantities
    • G06G7/48—Analogue computers for specific processes, systems or devices, e.g. simulators
    • G06G7/75—Analogue computers for specific processes, systems or devices, e.g. simulators for component analysis, e.g. of mixtures, of colours
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28C7/00—Controlling the operation of apparatus for producing mixtures of clay or cement with other substances; Supplying or proportioning the ingredients for mixing clay or cement with other substances; Discharging the mixture
    • B28C7/04—Supplying or proportioning the ingredients
    • B28C7/0404—Proportioning
    • B28C7/0418—Proportioning control systems therefor
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D11/00—Control of flow ratio
    • G05D11/02—Controlling ratio of two or more flows of fluid or fluent material
    • G05D11/13—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means
    • G05D11/131—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components
    • G05D11/133—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components with discontinuous action
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D11/00—Control of flow ratio
    • G05D11/02—Controlling ratio of two or more flows of fluid or fluent material
    • G05D11/13—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means
    • G05D11/131—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components
    • G05D11/133—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components with discontinuous action
    • G05D11/134—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components with discontinuous action by sensing the weight of the individual components
    • G—PHYSICS
    • G06—COMPUTING OR CALCULATING; COUNTING
    • G06G—ANALOGUE COMPUTERS
    • G06G3/00—Devices in which the computing operation is performed mechanically

Definitions

  • an analogue computing device for proportioning a plurality of components of a batch mixture in obtaining a composition exhibiting desired physical properties.
  • a typical example of such a mixture is concrete.
  • concrete comprises cement and water and as well known by those skilled in the art, the ratio between cemerit and water determines the concrete strength while the amount of water determines the slump.
  • the mix-operator knows, however, that if the customer wants a mixture with more water than in standard mixture then it is necessary to add more cement to make sure that the mixture keeps its strength, and for that reason mix-operators all over the world are inclined to overproportion the cement in such individually specified mixtures.
  • an analogue computing device which is programmed for reading in the analogue values of two of the components and which is also provided with means for dividing an analogue value which is the sum of an analogue value corresponding to the two components the ratio between which determines the first physical property and means for indicating that ratio.
  • This analogue computing device is used in such a manner that the ratio between said two last mentioned components is first adjusted to the value which determines the first physical property whereafter the amounts of that amount of the one of the two components which determines the other physical property is adjusted until a predetermined analogue value can be read out whereafter the analogue values are used for proportioning the batch.
  • the merits of the present invention are that it provides a very simple method and a correspondingly simple preprogrammed analogue computer which can be used by any mixoperator after short training without any knowledge of analogue computers because it is preprogrammed and the operation is limited to the adjustment of a few controls and the reading of a few indicators which even may be calibrated to indicate the desired physical properties directly.
  • the method is so simple that mistakes can be practically completely avoided.
  • the simplest possible analogue computer has the character of a slide rule and provides two rulers which are reciprocal in two directions with an angle of therebetween into engagement with an abutment on an arm which is pivotable about the point of intersection between two sidelines of a hypothetical equilateral triangle in which the sides are perpendicular on the direction of reciprocation of the two rulers and with the position of the abutment relatively to the two sidelines of the triangle being readable on a scale.
  • a mechanical-geometrical system based on this principle can obviously be constructed by means of rails and reciprocal rulers and by using the reciprocating of the rulers, if desired, in connection with mechanical amplifiers the reciprocation of the rulers can be used directly or indirectly to control the supply of the components in amounts corresponding to the analogue values readable on the rulers from automatic weighing devices.
  • An analogue electrical system which enables the same simple method to be used can, however, be constructed by means of voltage dividers which provide an electrical analogue computer which is preprogrammed to use the method.
  • voltage dividers which provide an electrical analogue computer which is preprogrammed to use the method.
  • a simple analogue computer for proportioning three components of a batch comprises basically only two voltage dividers, each having an adjustable tapping.
  • the first voltage divider is connected across the voltage source and thereby supplied with an input voltage which corresponds to the analogue value of the total amount of the batch.
  • the other voltage divider is connected between the variable tapping of the first voltage divider and one end thereof.
  • the adjustment of the tapping of the second voltage divider is made readable either by a graduation of a control member or by means of a suitable instrument.
  • Output terminals are connected with each end of the first voltage divider as well as with the two variable tappings.
  • An indicator is provided for reading out the voltage which corresponds to one of the portions into which the second voltage divider divides the potential thereacross so as to readout the analogue value of one of the components.
  • a simple analogue computer of this kind with two potentiometers can be used for carrying out the method whereby the variable tapping of the second potentiometer first is adjusted to the desired ratio between the two components until the indicator shows the ratio, whereafter the variable tapping of the first potentiometer is regulated until the desired analogue value of one of the two components is indicated between the outlets which are connected with the two variable tappings of the potentiometers.
  • the first adjustment determines the ratio between cement and water
  • the second adjustment regulates the ratio between gravel and cement plus water.
  • the ratio is kept constant, and the amount of cement and water is readjusted with the ratio therebetween maintained until the desired amount of water can be read out of the computer.
  • a third component of a mixture such as a filler has a content of one of the two other components.
  • the gravel is wet, Le. a part of water is included in the gravel.
  • the invention also enables a correction for such a case. Obviously, if there is for example l percent water in the gravel, the amount of water used must be reduced correspondingly because otherwise the adjusted cement/water ratio will not be kept.
  • this can be compensated for by measuring the amount of one component which is contained in the other component and using an analogue computer which comprises an adjustable summator device which is operatively connected with the outputs for the two components.
  • analogue computer which comprises an adjustable summator device which is operatively connected with the outputs for the two components.
  • the quality of one of the components differs from one supply thereof to the next. It is well known that the quality of cement differs and it has therefore previously been necessary to dispense sufficient cement to ensure that cement of the poorest quality always will give the desired strength of the concrete.
  • the strength of concrete is governed by the coefficient of variation, variations of the quality of the cement increase the coefficient of variation. The more uniform the cement quality is, the smaller becomes the coefficient of variation.
  • the invention also provides for automatically readjusting the dispensing of that one of the components of a mixture the quality of which varies from supply to supply in such a manner that in order to keep a substantially uniform physical property of the mixture and savings with respect to the components in question a relatively increased amount of the component is dispensed when the quality is poor, while a relatively smaller amount of the component is dispensed when the quality is better.
  • the analogue value of the component in question is adjusted as a reference value derived from the physical properties of a reference mixture whereafter a test mixture is produced with a different quality of the component in question and the physical properties of the test mixture are derived whereafter a digital ratio between the two physical properties is calculated and an adjustable multiplication device which is connected with the analogue value of the component in question as adjusted according to the reference mixture is adjusted to the ratio calculated so as to thereby produce a corrected analogue value of the component in question which corresponds substantially to the amount of the component which with different quality will produce substantially the same physical property of the mixture in which the component of different quality is used.
  • this method can be used in such manner that the reference value of the analogue amount of cement is adjusted according to a reference mixture for which the factor K in Bolomeys formula is calculated whereafter the strength of a test mixture in which a different cement quality is used is determined and the K-factor of the test mixture is calculated, whereafter the multiplication device is adjusted on the ratio between the two K-factors and the analogue value for the amount of cement of different quality is derived from the multiplication device.
  • FIG. I is a diagrammatic illustration of controls, indicators and analogue values illustrating schematically the connections in order to explain the method. and the principle of an analogue computer according to the invention
  • FIG. 2 is a perspective illustration of a computing device according to the invention
  • FIG. 3 is a schematic illustration of a mechanical geometrical system which provides a part of an analogue computer according to the invention with appertaining electrical equivalence for that part of the computer,
  • FIG. 4 is an illustration similar to that of FIG. 3 with respect to other parts of the computer,
  • FIG. 5 is a schematic combination of the systems of FIGS. 2 and 3,
  • FIG. 6 is a complete mechanical geometrical system constructed according to the principles of FIGS. 3 and 4 and 5,
  • FIG. 7 is the electrical equivalence of FIG. 6,
  • FIG. 8 is a schematic illustration of the control of dispensing one component by using the electrical analogue value of the amount of components as reference voltage
  • FIG. 9 is a schematic illustration of a further modification of the principle of FIG. 3,
  • FIG. 10 is a schematic illustration of a simple calculating device based on the mechanical geometrical system
  • FIG. 11 is a detail of the calculating device of FIG. 10.
  • FIG. 12 is a diagrammatic illustration of a part of an analogue computer according to the invention for automatically correcting the analogue value of one of the components, in response to variations of quality of the component, and
  • FIG. 13 is the circuit arrangement of FIG. 12 illustrating a further automatic correction of a third component in response to the variation of the analogue value of the component the quality of which varies.
  • FIG. 1 illustrates schematically the principles of an analogue computer for adjusting the desired amounts of seven analogue values L, C, W, G, 8,, S and S corresponding to the amounts of seven components of a composite product.
  • the components will in the following by referred to by the same capital letters as their analogue values. It is supposed that the ratio between the analogue values or components C and W determines one physical property of the composite product and that the absolute analogue value or amount of W determines another physical property.
  • the computing device has a first control member K, which by means of connections f and 1], shown in dotted lines and symbolizing adjustments is connected with analogue outputs for the values C and W so as to adjust the ratio therebetween.
  • the control K is also connected with a ratio indicator I, operable to indicate the ratio W/C.
  • the computing device furthermore has another control member K, which through one connection f, is connected with the analogue output G and through another connection f is connected with the total analogue output C+W.
  • the control member K is furthermore connected with an indicator I, which indicates the value of the analogue value W and preferably also with indicators I and I, which indicate the values of C and G respectively.
  • the method of using this part of the computing device is as follows:
  • the ratio between the analogue values C and W is first adjusted by means of the control member K, until the desired ratio is readable on the indicator l corresponding to the physical property of the composite product which is determined by the ratio W/C.
  • the indicator I may within the scope of the invention be an instrument or a graduated scale or any other type of indicator.
  • the ratio (C+W):G is adjusted by means of the control member K Obviously, the ratio W/C as previously adjusted by means of the control member K, will not be influenced by the adjustment of the control member K but the analogue values W and C are changed, still with the same proportion between them.
  • the indicator l shows the desired amount of the component W which is required in the mixture in order to obtain the second physical property, all the three analogue values will be correctly adjusted and the components can be dispensed in accordance with the analogue values to provide a composite mixture in which the physical properties will be as determined by the ratio W/C as well as by the absolute amount of W.
  • the mixture is concrete in which the analogue values C, W and G stand for the components, cement, water and gravel.
  • the ready-mix operator of a concrete station knows that within practical limits the strength is determined by the ratio between water and cement and that the second physical property, namely the slump, is determined by the contents of water.
  • the part of the analogue computer briefly described hereinbefore provides for a method which avoids the danger of overdispensing cement and thereby wasting cement when the customer requires an individually composed mixture with a certain absolute amount of water in order to obtain a certain slump.
  • the method obtaining an immediate answer to the correct composition of a concrete mixture is that the water/cement ratio is first adjusted to obtain the desired strength by reading the ratio on the indicator I,, whereafter the amount of water is adjusted until the desired amount is readable on the indicator 1
  • the analogue value C of cement is readjusted because the water/cement ratio is kept constant so that a mixture is always obtained with the desired strength as determined by the control member K, and there is no risk of overdispensing the cement with waste as a result or of underdispensing with less strength as a result.
  • concrete In addition to cement/water and gravel, concrete usually contains entrained air L and skeleton composed of different modules aggregate or sizes of stones 5,, S, and S; which in the following will be supposed to be small, medium and large sizes of stones.
  • the computer device has a control member K with one connection f,, operable to adjust the analogue value of S another connection f, operable to adjust the analogue values S +S and an indicator 1,, for the amount of stones 8,.
  • a further control member K has connections f, and f operable to adjust the ratio between the stones S, and S; as well as a connection to indicators I and I for indicating the values of these analogue values.
  • a further control member K,; is provided with connections j ⁇ , and f, to adjust the ratio between the entire amount of stones S,+S,+S and the entire amount of all the components in the mixture as well as an indicator I,, for indicating some of the analogue values S,+S +S in proportion to the sum of all the analogue values.
  • control member K By initially setting the control member K to read a unit value of the amount S +S +S on the indicator I, such as for example by volume and determining that for example the ratio between 5,, S and 8; should be 50:30:20 it is possible to obtain the adjustment in the following manner:
  • the control member K is operated until the indicator S, shows 50 whereafter the control member K,, is operated until the indicators S and 8;, show 30 and 20 respectively.
  • the control member K When thereafter the control member K is operated and the analogue value of the total batch amount also is a unit value. for example 1,000, and it is desired to have for example 40 percent skeleton in the mixture, this can be adjusted directly by means of the member K,;, by calibrating the indicator l,, to show percent. Thereby the exact analogue values of the three amounts 8,, S and 8;, will be readjusted but the initially adjusted ratio will be kept constant.
  • the analogue value L for entrained air is adjustable relatively to the entire sum of analogue values by means of a member K by means of connections 1",, and f, as indicated, and the contents of entrained air as adjusted thereby can be read out in percent on the indicator I
  • the total amount of cement, water and gravel is the difference between the entire batch amount and the sum of contents of air and skeleton.
  • the final step of determining the composition is thereafter to use the controls K, and K. as hereinbefore described to determine the water/cement ratio according to the desired strength and the amount of water according to the desired slump.
  • the slump is also governed by the largest size of stones which must be smaller than the narrowest cross section of the mould. Since the stones already have been selected according to previous adjustments, the adjustment of K, is the actual slump determination.
  • the method of using the schematically shown computing device of FIG. 1 is extremely simple and provides for quickly obtaining the correct analogue values of an individually specified mixture. We have found that the method is so simple that it is possible with relatively short training to teach the mix-operator of a concrete station to use the method and obtain the correct answer in less than I minute.
  • FIG. 1 A practical design of an analogue computing equipment according to the invention is illustrated in FIG. 1 in which 100 is a control panel on the front side of which the various control members K 8,, are shown in the form of control knobs and in which also the indicators are shown as readable instruments.
  • control knob assembly which in FIG. 1 is referred to by KP represents means for adjusting the analogue values and ratios therebetween and once a predetermined batch of a composite product has been calculated and the analogue values adjusted, the computing device can be used to reproduce the same composition by retaining the controls.
  • Stl, Stll StX indicate each one of ten different groups of controls which by way of trimming are adjustable to respond to each one of ten different standard mixtures and can be selected individually by means of corresponding selector members Sel. Sell SeX of a selector board 102 which is connected with the control panel 100 by means of a cable I04.
  • FIG. 2 The arrangement of FIG. 2 is such that all the indicators are common to each of a selected one of control groups whether it is the group for individual adjustment KP as shown in FIG. I. or any one of the standard mixture groups Stl, Stll
  • the selector board 102 has in addition to the selectors SeI, Sell a selector K, for selecting the group of controls KP for individual batch mixing.
  • adjustment members of the group of selectors KP may be in the form of control knobs or the like which can be individually adjusted
  • the corresponding control members of the standard mixture controls should be designed in such a manner that they can only be readjusted by means of special tools or the like and only for the purpose of minor readjustments or trimmings.
  • the groups of standard mixture controls correspond individually with respect to their connections with the instruments and the analogue value outputs to the control group KP of FIG. 1, and it will be appreciated that initially they have to be adjusted individually precisely in the manner described hereinbefore to correspond to selected standard mixtures.
  • the selector board I02 may be arranged on the platform where the mix-operator can surbey the delivery and can select either a specified one of the standard mixtures by pushbutton control or the individual control selector group KP of FIG. 1 in the case where a mixture which deviates from 'any of the available standard mixtures is specified.
  • the control panel of FIG. 2 has in addition to the controls hereinbefore described a pushbutton SW and two other controls K and K the function of which will be described in the following and the selector board 102 has a further control K the function of which also will be described in the following.
  • the selector board is connected with a cable 106 which is the output cable from the entire computer device and adapted to be connected with the dispensing equipment for automatic dispensing of the individual components according to the adjusted analogue values of each of them.
  • the adjustment procedure is the same the whole way through and always starts with adjusting the ratio between two numerical values and -after the first adjustment another adjustment of ratio between two numerical values is effected and so forth, all in accordance with a pattern which is related to the technology of the mixture to be produced.
  • This simple method provides for a simple construction and preprogramming of an analogue computing device, either in the form of a simple mechanical calculation device or an equivalent electrical computer as will be described in the following.
  • FIG. 3 illustrates a mechanical geometric system and the corresponding electrical equivalent for determining the analogue values of C, W and G.
  • the mechanical geometrical system comprises three rulers C,, W, and G, each of which extends perpendicularly to each one of three sidelines a, b, and c of a hypothetical triangle or as a system of guide members constructed as an equilateral triangle with a height M which may be variable.
  • An arm K which corresponds to the control member K, of FIG. 1 and therefore is designated by the same reference numeral is pivotally mounted about a top A of the triangle and points on a scale I, which is the equivalent of the indicator l,of FIG. 1.
  • the interior ends of the rulers C,, W, and G, are adapted to engage or are connected with an abutment K, which corresponds to the control member K of FIG. 1 and which is movable along the geometrical line which coincides with the longitudinal direction of the arm K,.
  • This abutment may either be reciprocally mounted on the arm K,, or the arm may be reciprocally mounted with the abutment firmly secured on the arm.
  • the geometrical system of FIG. 3 is based on the discovery that the geometry of equilateral triangles and the electrical analogy thereof provide a computing aid for proportioning components of a mixture to fulfil requirements as hereinbefore described.
  • the geometrical system is used in the simple manner that the arm K, first is adjusted to read the desired ratio f on the indicator I,. Thereby the ratio W:C is adjusted and this ratio is kept constant during displacement of the abutment I( along the arm K,. By displacing the abutment K until the desired analogue value W can be read on the ruler W, a mixture is calculated with the desired water/cement ratio and the desired amount of water whereby the analogue values of gravel and cement can be read on the rulers C and W,.
  • the corresponding electrical equivalent of the geometrical system is also included in FIG. 3 and comprises a voltage di vider P, in the form of a potentiometer with a movable tapping K,,.
  • a further potentiometer P is provided with a variable tapping K, which is provided with an indicator (not shown) corresponding to the indicator I, in FIG. 1, so that for example the control knob of the potentiometer points on a scale which is graduated corresponding to the scale I, of FIG. 3.
  • the two variable tappings are connected with output terminals MS and MS and the ends of the potentiometer P, is connected with output terminals OM and OMS.
  • An indicator I, for the analogue value of water is provided between the two variable tappings of the potentiometers and further indicators L and 1,, corresponding to those of FIG. 1 may be provided between the other output terminals.
  • the tapping K, of the potentiometer P corresponds to the arm K, of the geometrical system and the tapping K of the potentiometer P corresponds to movement of the abutment K along the line of the arm K,.
  • the electrical system of FIG. 3 is used for proportioning the concrete mixture in such manner that when a predetermined strength is specified, the water/cement ratio is first adjusted by means of the tapping K, until the desired ratio can be read on the indicator.
  • the tapping K is adjusted until the indicator I,, shows a predetermined amount of water corresponding to the desired slump
  • the outputs C, W and G between the output terminals are electrical voltages corresponding to the analogue values of each of the three components.
  • I A similar mechanical geometrical system with electrical analogy is shown in FIG. 4 adapted to adjust between the three sizes of stone in the skeleton as well as adjusting the ratio between skeleton and the total amount of the batch.
  • the three rulers are designed by the analogue values 5,, S, and 8:, as readable inside the orbits of the triangle.
  • the three rulers are connected at a point AN where two pivotable arms K and K intersect.
  • the ratio between 8,, S and S will be expressed in percent and can be indicated on correspondingly calibrated scales on the rulers S S and 8,.
  • the length of the rulers inside the triangle will be reduced while retaining the adjusted proportions in percent and when the control member K has been adjusted to the desired ratio g according to the last one of the two formulas hereabove the actual analogue values of 8,, S and 8;, can, by correspondingly calibrated scales of the rulers, be read out of the device.
  • the electrical analogy of FIG. 4 comprises an input potentiometer D which an input potential is applied.
  • the input potential By initially adjusting the variable tapping K of the potentiometer D, to the top of the potentiometer as indicated in dotted lines the input potential will be applied across the potentiometer A, which is provided between the variable tapping K and the bottom of the potentiometer D and by means of the variable tapping K of the potentiometer A, and the variable tapping K, of the potentiometer B, which is provided between tapping K and the bottom of the potentiometer A, the input voltage can be divided in the proportions azbzc with the proportions readable on the indicators I I, and in percent.
  • variable tapping K of the potentiometer D is adjusted to the desired ratio between the entire amount of skeleton and the entire batch amount as readable in percent on the indicator I the analogue output values between the output terminals OMS, 08,, OS, and CS respectively will be proportionally reduced, while retaining the percentage adjustment between the three components.
  • Such a single component can be symbolized by the height of an equilateral triangle.
  • the height of the triangle of FIG. 3 which is referred to by M corresponds to the entire amount of mortar which is water plus cement plus gravel and the height of the triangle of FIG. 4 when adjusted to the desired percent of skeleton in the entire mixture corresponds to the skeleton.
  • the triangle of FIG. 3 can therefore be referred to as the M-triangle, and the triangle of FIG. 4 as the S-triangle.
  • analogue computer Since it is desired in analogue computer to have the analogue value corresponding to the entire batch by way of a unit analogue such as L000 corresponding to, for example l m which is equal to 1,000 litres, it is in FIG. 5 supposed that in such cases where there will be more air than the natural 2 percent in the mixture, the compensation for different air contents is obtained by diminishing the amount of mortar by displacing the bottom line of the M-triangle to read in the percent of air on a correspondingly calibrated scale I corresponding to the indicator I, of FIG. 1.
  • FIG. schematically indicates a combination of the systems of FIGS. 3 and 4, a more specific combination of the geometrical mechanical systems of FIGS. 3 and 4 is illustrated in FIG. 6.
  • the apparatus comprises a system of rails with stationary rails M.., M, and M M which form the sides in two oppositely directed equilateral triangles with tops A and A the distance between which can be indicated on a scale I, to be adjusted according to a unit analogue value of the entire amount such as for example I rn. equal to 1,000 liter.
  • the bottom rail M,- of the M-triangle can be displaced by means of an adjustment member K to indicate the distance between the two triangles L corresponding to the contents of entrained air on a scale I, which extends from the horizontal line M of the S-triangle.
  • the water/cement ratio is calculated from a formula to give the desired strength.
  • the volume of air is taken from a table.
  • the approximate quantity of water needed to produce the desired slump is taken from a table whereafter the exact volume of water can be calculated. Thereafter, knowing the water/cement ratio, the exact volume of cement can be calculated. Thereafter the percent of coarse aggregate or skeleton can be taken from a table. The volume of sand can then be calculated. Eventually, by multiplying with the specific gravity, the batch quantities can be calculated. Such calculation based entirely on concrete theory requires an expert and will take him between 1 and 2 hours.
  • the proportioning aid or computing device By means of the proportioning aid or computing device according to the invention it is only necessary to read the proportions as specified, i.e. a,'b, c, d, e andfinto the device, i.e. to put the data into the device, which is a simple manual procedure. and by eventually adjusting g until the analogue value of water W indicates the desired amount, all the other values readjust themselves and all the batch quantities can be read out of the device. The whole procedure takes less than 1 minute and the use of the device does not require an expert.
  • the adjustment member K is initially set in a position corresponding to a unit amount of total skeleton so as thereby to enable the proportions between S, and S, and S to be read out in percent.
  • the line M of the S-triangle is thereafter displaced until the percentage contents of skeleton relative to the entire amount is readable on the scale I,,.
  • pivotable arm K is adjusted to read the ratio f between water and cement on the scale I and eventually the abutment K, is displaced until the desired amount of water W is readable on the appertaining ruler on the M-triangle.
  • FIG. 7 The electrical analogy of the geometrical system of FIG. 6 is shown in FIG. 7 in which the electrical analogies of FIGS. 3 and 4 are combined.
  • This analogue value is readable on an indicator I, and corresponds to the geometrical distance between the tops A and A of the triangles of FIG. 6.
  • the potentiometer D of FIG. 5 is connected directly over the input terminals so as to enable the proportion L:(L+C+W+G+S +S +S to be directly adjusted on this potentiometer and the analogue value of the amount L of entrained air can be read between the output terminals 0L and OM on the indicator I,
  • the potentiometer D is also connected directly across the input terminals I and 1,
  • the variable tapping K of the potentiometer D is connected with the output terminal OMS.
  • the skeleton voltage S is divided into three portions by means of the potentiometers A and B, of FIG. 4 and in a similar manner the mortar voltage M is divided into three portions by means of the potentiometers P, and P, of FIG. 3.
  • the terminal IT is connected with the variable tapping K of the potentiometer D through a connection in which a manually operable switch S, is provided so as to enable the input voltage to be applied directly across the input potenita sfsr tsiths ke et voltage v
  • the ratio indicator for W:C is a differential coil instrument, the two coils of which at one end are connected with the variable tapping K, and the other ends of each of the coils are connected with the outputs OM and M8 respectively.
  • variable tapping K of the potentiometer B, is adjusted until the desired percent ratio of stones of size S is readable on the indicator I
  • the latter adjustment also automatically adjusts the analogue output voltage S to the desired percent of the amount of stones of size 8;, so that the three amounts S +S +.S':,----l00 percent.
  • variable tapping K, of the potentiometer D is thereafter adjusted until the indicator 1,, indicates the r desired percent of skeleton in the entire amount.
  • the air is accordingly adjusted by setting the variable tapping K
  • the total batch analogue voltage has been disposed of with respect to the skeleton and the air, and the remaining voltage which is now disposable is between the terminals OM and OMS.
  • the remaining adjustment is now to divide the remaining output voltage between the output terminals OM and OMS ac cording to specified strength and slump which is done in the following manner.
  • the tapping K is adjusted until the desired water/cement ratio is readable on the indicator I, which may be calibrated directly according to the strength of the concrete.
  • tapping K is adjusted until the specified amount of water is readable on the indicator I
  • the amounts of gravel and cement are automatically readjusted and both amounts can be read out on the instruments I and I, and the output voltages C and G correspond to the adjusted values.
  • a remote control instrument panel may be provided with indicators which give precise instructions to the personnel about the amount of each individual component.
  • each instrument should be calibrated to show the exact amount of each component by volume or by weight according to standard practice.
  • the instru ments for the commands may be digital instruments giving the amounts by weight or volume in exact figures.
  • the proportioning or computing device with output voltage fractions each of which is the analogue value of one componentwhich also may be derived from a triangle system to which electrical output devices are added-lends itself to a substantially complete automatic administration by combining the application of a analogue output voltages as amount control voltages to the corresponding respective administration stations with sequence control operable to select the stations in sequence one after the other in response to the programmed completion of the operation of each station.
  • analogue output values from the computing device to control automatic dispensing of the components in a weighing station can be achieved by means of a device in the weighing station which produces an analogue value which increases as the dispensing proceeds, a differential which compares the analogue value produced in the weighing station and control means operable to interrupt the dispensing when the analogue values have become equal.
  • a stepwise interruption of the dispensing will be used in such a manner that the rate of dispensing will be decreased at a predetermined stage of the dispensing such as at a predetermined difference between the analogue value supplied by the computer and the corresponding voltage supplied by the weighing stations such as for example corresponding to dispensing of between and percent of the predetermined amount so as to thereby ensure against overdispensing of any of the components.
  • FIG. 8 Such a dispensing arrangement is shown schematically in FIG. 8 and illustrates the arrangement in connection with the dispensing of one of the components, for example the cement.
  • 50 is a silo with a closure member 52 the opening and closing of which can be controlled by a control member 54 and which can be partly closed from the open condition by means of a control member 56.
  • the closure member When the closure member is open the material is guided from the silo 50 along a chute 58 or in any other suitable manner to a weighing device 60 with a scale 62 which indicates the amount of material supplied to the weighing device.
  • An arrangement operable to produce a potential is connected with the weighing device and comprises a voltage source BW and a potentiometer P with a variable tapping K which is moved by the movable parts of the weighing device as the dispensing proceeds so as to thereby produce an increasing voltage C between the top of the potentiometer P and the variable tapping K Obviously, when the analogue voltage C corresponding to the desired amount of the component in question is supplied across the input terminals i and I of the device, it is possible to use a differential which compares the analogue input voltage and the voltage produced by the weighing device and which interrupts the dispensing when the desired amount is supplied to the weighing device.
  • the voltage source BW is adjustable and is initially adjusted to a value which by the dispensing of an amount of cement by weight between the tapping K,,,, and the top end of the potentiometer P produces a voltage C,,, which is equal to the analogue input voltage between the terminals I, and I when the cement amount indicator l which is calibrated according to weight indicates the same amount of cement.
  • a multiplication amplifier in the form of an operational amplifier 0A with feedback over a potentiometer P by means of which the multiplication factor of the amplifier can be adjusted.
  • analogue computer is constructed to always give an analogue voltage portion corresponding to the values of the individual components corresponding to a total batch volume of for example 1 m.
  • the output of the amplifier 0A is connected with the input terminal I through a differential device indicated by way of a relay R, with a normally closed contact K which is connected with the control device 54 for closing the closure member 52.
  • the differential member R. is shunted by another .differential member R, which is provided with a bias in such a manner that it will be actuated when the output voltage from the amplifier CA has been increased to a value which is slightly less than the value at which the differential device R. will respond.
  • the relay R has a contact K which is normally closed and which is opened to actuate the control device 56 to partly close the member 52 when the device R is actuated.
  • the bias for the relay R is ,produced by supplying an alternating voltage across a potentiometer P, between the variable tappings of which and the one end of the primary winding of a transformer T, is connected with a secondary winding in which a rectifier E, is connected.
  • the arrangement of FIG. 8 indicates schematically the arrangement used for one of the components, for example the cement and it will be appreciated that similar arrangements are used for the other components and are adjusted from a central location such as from the selector board 102 of FIG.
  • control member K is operable to adjustthe amplification factors of the potentiometers as well as the tapping of the potentiometer P, to thereby regulate the bias of the relays R in accordance with the ratio between the total amountto be dispensed and the unit amount corresponding to the analogue values supplied from the computing device.
  • the mode of operation of the arrangement of FIG. 8 is substantially as follows:
  • the tapering K of the potentiometer P is moved and depending on the amplification factor of the amplifier CA as adjusted by means of the proportion selector member l( of the selector board of FIG. 2 the analogue voltage C produced by the weighing device is converted into. an analogue voltage C... which is equal to the unit value of the computing device.
  • the voltage C increases the differential device R,, will first be actuated when the voltage supplied from the amplifier 0A is slightly less than the input analogue voltage or reference voltage C.
  • the contact K is opened and actuates the control member 56 to partly close the member 52 so as to thereby decrease the rate of dispensing of the component.
  • the differential device R is actuated and actuates the control member 54 to close the member 52 and thereby interrupt the dispensing.
  • the other components are dispensed in a similar manner by means of similar control arrangements either simultaneously by means of individual weighing devices or in sequence controlled by a suitable sequence control.
  • an arrangement in FIG. 12 can be included in the computing device or added to an existing computing device.
  • FIG. 12 provides for automatic adjustment of the analogue value of that component of a mixture which varies with respect to quality.
  • FIG. 12 enables a simple method for correcting the dispensing in response to changes in the quality of one component by using in the beginning the calculated analogue value of the component in question as based on a known mixture and adjusting a multiplication device in the analogue computer to the ratio between two digital values which can be calculated from proportions between the physical properties of the known mixture as a master mixture or reference mixture and a test mixture produced with a part of the component from a new supply.
  • the strength of the concrete is governed by the coefficient of variation which is the ratio between the crush strength of the concrete by standard deviations and the middle crush strength. Variations in the strength of the cement which can be quite substantial from supply to supply increase the coefficient of variations substantially but by uniform cement quality the coefficient of variation is reduced whereby the otherwise necessary strength margin can be reduced and result in savings of cement.
  • the proportion between the strength of a known mixture and a mixture to be produced subsequently can be expressed by the ratio between two digital values.
  • the crush strength of a concrete mixture after 28 days can be calculated by using Bolomey's formula in which is the crush strength for example in kg/cmfi, K is a constant which primarily depends on the strength of the cement, C, is the cement by weight and W is the water by weight.
  • the computing device of FIG. 12 is especially constructed for this method in connection with concrete mixing.
  • FIG. 12 AC is an analogue computing device with input terminals I, and I, for reading in the analogue values of the amountC, of cement which is necessary in the reference mixture with the known factor K and with input terminals I, and I, for reading in the analogue amount of water W
  • the ratio between water and cement can be adjusted on a potentiometer P, so that the calculation device of FIG. 12 can be directly connected with a computing device of FIG. 7.
  • the analogue computing device of FIG. 12 may, however, also be used in connection with other kinds of devices which are able to produce analogue values corresponding to the desired amounts of cement and water in a reference mixture.
  • FIG. 12 The arrangement of FIG. 12 is provided with an adjustable control member K which is also shown as an adjustment member in FIG. 2 for adjusting the ratio K zK and output terminals O', and 0",. for reading out analogue value C of the amount of cement which is to be used in the new mixture with quality of the new supply.
  • the arrangement also has output terminals 0' and 0",, for reading out the amount of water W
  • the amount of water is kept constant in order to secure the same slump of the new mixture as of the reference mixture.
  • an analogue multiplicator is provided which when the ratio K zK is adjusted by means of the member K automatically gives the correct analogue value of cement C If the specific gravity of cement which is 3.15 is inserted in the last of the formulas hereabove, the following expression for the amount of cement C by volume is found as By means of the system of voltage dividers shown in FIG.
  • 0A is an operational amplifier which is connected as a multiplicator.
  • the potential between the terminals I, and I should be proportional with the expression in parenthesis in the formula, i.e. proportional with C,,,(). l 59'W so as to obtain direct proportionality with adjustment of the potentiometer R between the input on the terminal I, and the output on the terminal O',.
  • the potential which must be added to the expression in parenthesis is 0.159-W and this potential must be applied between the input terminal I and the output terminal O,. This condition can be obtained by the following proportion between the resistors R, and R,
  • the analogue output values are calculated by volume. Since the volume of water the analogue of which is the same between the output terminals 0' and 0",, as between the input terminals I and I, and since it is always desired to deliver a volume unit, the system is also adapted to automatically recalculate the analogue value of such a third component of the mixture the amount of which can be allowed to be increased or decreased in response to decreasing or increasing of the amount of cement.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Computer Hardware Design (AREA)
  • Chemical & Material Sciences (AREA)
  • Mathematical Physics (AREA)
  • Analytical Chemistry (AREA)
  • Dispersion Chemistry (AREA)
  • Preparation Of Clay, And Manufacture Of Mixtures Containing Clay Or Cement (AREA)
US640571A 1966-05-24 1967-05-23 Composite mixture batching Expired - Lifetime US3609316A (en)

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Cited By (24)

* Cited by examiner, † Cited by third party
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US4318177A (en) * 1978-12-21 1982-03-02 Elba-Werk Maschinen-Gesellschaft Mbh & Co. Method of feeding water to a concrete mix
US4353482A (en) * 1980-01-23 1982-10-12 Halliburton Company Additive metering control system
US4433701A (en) 1981-07-20 1984-02-28 Halliburton Company Polymer flood mixing apparatus and method
US4538222A (en) * 1983-04-06 1985-08-27 Halliburton Company Apparatus and method for mixing a plurality of substances
US4538221A (en) * 1983-04-06 1985-08-27 Halliburton Company Apparatus and method for mixing a plurality of substances
US4569025A (en) * 1982-06-02 1986-02-04 Paul Eirich Method of preparing foundrys and by measuring moisture and compressibility
US4779186A (en) * 1986-12-24 1988-10-18 Halliburton Company Automatic density control system for blending operation
US4916631A (en) * 1986-12-24 1990-04-10 Halliburton Company Process control system using remote computer and local site control computers for mixing a proppant with a fluid
US5014218A (en) * 1986-12-24 1991-05-07 Halliburton Company Using a remote control computer connected to a vocal control computer and a monitor computer
US5452954A (en) * 1993-06-04 1995-09-26 Halliburton Company Control method for a multi-component slurrying process
US5522459A (en) * 1993-06-03 1996-06-04 Halliburton Company Continuous multi-component slurrying process at oil or gas well
US5541855A (en) * 1991-08-28 1996-07-30 Atrof Bauphysik Ag Device for testing unset concrete and mortar
US5959870A (en) * 1998-02-20 1999-09-28 Gamma-Metrics Real-time optimization for mix beds
US6113256A (en) * 1998-11-09 2000-09-05 General Electric Company System and method for providing raw mix proportioning control in a cement plant with a fuzzy logic supervisory controller
US6120173A (en) * 1998-11-09 2000-09-19 General Electric Company System and method for providing raw mix proportioning control in a cement plant with a gradient-based predictive controller
US20050276153A1 (en) * 2004-06-14 2005-12-15 Systech, Inc. Integrated control system
US20060287773A1 (en) * 2005-06-17 2006-12-21 E. Khashoggi Industries, Llc Methods and systems for redesigning pre-existing concrete mix designs and manufacturing plants and design-optimizing and manufacturing concrete
US20070153622A1 (en) * 2005-12-30 2007-07-05 Dykstra Jason D Methods for volumetrically controlling a mixing apparatus
US20070153623A1 (en) * 2005-12-30 2007-07-05 Dykstra Jason D Methods for determining a volumetric ratio of a material to the total materials in a mixing vessel
US20070266905A1 (en) * 2004-08-20 2007-11-22 Amey Stephen L Admixture dispensing system and method
US20130104778A1 (en) * 2009-10-21 2013-05-02 Reco Cement Products, LLC Cementitious Compositions and Related Systems and Methods
US8491717B2 (en) * 2011-12-12 2013-07-23 Verifi Llc Multivariate management of entrained air and rheology in cementitious mixes
US9290416B1 (en) 2011-11-21 2016-03-22 Louisiana Tech Research Corporation Method for geopolymer concrete
US12049023B2 (en) 2019-05-10 2024-07-30 Gcp Applied Technologies Inc. Instrument for direct measurement of air content in a liquid using a resonant electroacoustic transducer

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US3186596A (en) * 1962-01-25 1965-06-01 Industrial Nucleonics Corp Concrete batch blending control system

Cited By (43)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4318177A (en) * 1978-12-21 1982-03-02 Elba-Werk Maschinen-Gesellschaft Mbh & Co. Method of feeding water to a concrete mix
US4353482A (en) * 1980-01-23 1982-10-12 Halliburton Company Additive metering control system
US4433701A (en) 1981-07-20 1984-02-28 Halliburton Company Polymer flood mixing apparatus and method
US4569025A (en) * 1982-06-02 1986-02-04 Paul Eirich Method of preparing foundrys and by measuring moisture and compressibility
US4538222A (en) * 1983-04-06 1985-08-27 Halliburton Company Apparatus and method for mixing a plurality of substances
US4538221A (en) * 1983-04-06 1985-08-27 Halliburton Company Apparatus and method for mixing a plurality of substances
US4779186A (en) * 1986-12-24 1988-10-18 Halliburton Company Automatic density control system for blending operation
US4916631A (en) * 1986-12-24 1990-04-10 Halliburton Company Process control system using remote computer and local site control computers for mixing a proppant with a fluid
US5014218A (en) * 1986-12-24 1991-05-07 Halliburton Company Using a remote control computer connected to a vocal control computer and a monitor computer
US5541855A (en) * 1991-08-28 1996-07-30 Atrof Bauphysik Ag Device for testing unset concrete and mortar
US5522459A (en) * 1993-06-03 1996-06-04 Halliburton Company Continuous multi-component slurrying process at oil or gas well
US5570743A (en) * 1993-06-03 1996-11-05 Halliburton Company Continuous multi-component slurrying process at oil or gas well
US5452954A (en) * 1993-06-04 1995-09-26 Halliburton Company Control method for a multi-component slurrying process
US5959870A (en) * 1998-02-20 1999-09-28 Gamma-Metrics Real-time optimization for mix beds
EP0943565A3 (de) * 1998-02-20 2000-04-26 Gamma-Metrics Echtzeit-Mischbettoptimisierung
AU723878B2 (en) * 1998-02-20 2000-09-07 Gamma-Metrics Real-time optimization for mix beds
AU723878C (en) * 1998-02-20 2004-04-29 Gamma-Metrics Real-time optimization for mix beds
US6113256A (en) * 1998-11-09 2000-09-05 General Electric Company System and method for providing raw mix proportioning control in a cement plant with a fuzzy logic supervisory controller
US6120173A (en) * 1998-11-09 2000-09-19 General Electric Company System and method for providing raw mix proportioning control in a cement plant with a gradient-based predictive controller
US20050276153A1 (en) * 2004-06-14 2005-12-15 Systech, Inc. Integrated control system
US20070266905A1 (en) * 2004-08-20 2007-11-22 Amey Stephen L Admixture dispensing system and method
US20060287773A1 (en) * 2005-06-17 2006-12-21 E. Khashoggi Industries, Llc Methods and systems for redesigning pre-existing concrete mix designs and manufacturing plants and design-optimizing and manufacturing concrete
US7386368B2 (en) 2005-06-17 2008-06-10 Icrete, Llc Methods and systems for manufacturing optimized concrete
WO2006138732A3 (en) * 2005-06-17 2007-11-01 Icrete Llc Methods and systems for redesigning pre-existing concrete mix designs and manufacturing plants and design-optimizing and manufacturing concrete
EP1899776A4 (de) * 2005-06-17 2011-03-30 Icrete Llc Verfahren und systeme zum umentwerfen von bereits existierenden betonmischentwürfen und herstellungsanlagen und entwurfsoptimierung und herstelung von beton
US20080009976A1 (en) * 2005-06-17 2008-01-10 Icrete, Llc Methods and systems for manufacturing optimized concrete
US20080027583A1 (en) * 2005-06-17 2008-01-31 Icrete, Llc Computer-implemented methods for redesigning a pre-existing concrete mix design
US20080027685A1 (en) * 2005-06-17 2008-01-31 Icrete, Llc Methods for determining whether an existing concrete composition is overdesigned
US20080027584A1 (en) * 2005-06-17 2008-01-31 Icrete, Llc Computer-implemented methods for re-designing a concrete composition to have adjusted slump
US20080066653A1 (en) * 2005-06-17 2008-03-20 Icrete, Llc Optimized concrete compositions
US7567856B2 (en) * 2005-12-30 2009-07-28 Halliburton Energy Services, Inc. Methods for determining a volumetric ratio of a material to the total materials in a mixing vessel
US7561943B2 (en) * 2005-12-30 2009-07-14 Halliburton Energy Services, Inc. Methods for volumetrically controlling a mixing apparatus
US20070153623A1 (en) * 2005-12-30 2007-07-05 Dykstra Jason D Methods for determining a volumetric ratio of a material to the total materials in a mixing vessel
US20070153622A1 (en) * 2005-12-30 2007-07-05 Dykstra Jason D Methods for volumetrically controlling a mixing apparatus
US20130104778A1 (en) * 2009-10-21 2013-05-02 Reco Cement Products, LLC Cementitious Compositions and Related Systems and Methods
US8529689B2 (en) * 2009-10-21 2013-09-10 Reco Cement Products, LLC Cementitious compositions and related systems and methods
US9290416B1 (en) 2011-11-21 2016-03-22 Louisiana Tech Research Corporation Method for geopolymer concrete
US8491717B2 (en) * 2011-12-12 2013-07-23 Verifi Llc Multivariate management of entrained air and rheology in cementitious mixes
US20130272084A1 (en) * 2011-12-12 2013-10-17 Eric Koehler Multivariate management of entrained air and rheology in cementitious mixes
US8764273B2 (en) * 2011-12-12 2014-07-01 W. R. Grace & Co.-Conn. Multivariate management of entrained air and rheology in cementitious mixes
EP2790884A4 (de) * 2011-12-12 2016-03-02 Verifi Llc Multivariate verwaltung von eingespeister luft und rheologie in zementartigen mischungen
AU2011383344B2 (en) * 2011-12-12 2017-04-27 Verifi Llc Multivariate management of entrained air and rheology in cementitious mixes
US12049023B2 (en) 2019-05-10 2024-07-30 Gcp Applied Technologies Inc. Instrument for direct measurement of air content in a liquid using a resonant electroacoustic transducer

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Publication number Publication date
DE1648073A1 (de) 1971-03-25
FR1499991A (fr) 1967-11-03
NL6707211A (de) 1967-11-27
CH473428A (de) 1969-05-31

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