WO1998040701A1

WO1998040701A1 - Method and device for detecting quantities during milk collection using mobile or stationary collection systems

Info

Publication number: WO1998040701A1
Application number: PCT/EP1998/001113
Authority: WO
Inventors: Georg DÜCKINGHAUS; Alfons BRÜGGEMAN
Original assignee: Schwarte-Werk Gmbh
Priority date: 1997-03-13
Filing date: 1998-02-27
Publication date: 1998-09-17
Also published as: DE19710296C1

Abstract

The invention relates to method and device for detecting quantities during milk collection using mobile or stationary collection systems. The milk quantity volume to be delivered over a given distance is detected and determined as it is transferred from a first container to a second container. The inventive method makes it possible to determine the milk quantity without the limiting effect of an air separating jar. This is achieved inter alia by separating the milk flow formed during conveyance into a main flow and a secondary flow, by eliminating the air in the admixtures, by continuously applying and investigating ultrasonic impulses in the main flow and in the deaerated secondary flow and by measuring the respective sound propagation time and at least the temperature in the main flow, by determining the actual mean sound velocity of the flowing milk/air mixture therein and the actual mean sound velocity of the flowing deareated milk from the sound propagation time allocated thereto in the main flow, by calculating the real proportion of milk ζ(t) in the main flow on the basis of both sound velocities and the sound velocity in the air at the allocated main flow temperature. The milk quantity conveyed during a collection time tA required to convey the overall milk quantity is determined on the basis of the respective milk proportions ζ(t) and the mean flow velocity allocated thereto at a defined point of the conveyance path or on the basis of a defined proportional variable thereof so that a defined point of the conveyance path can be determined along with the effective milk volume VMO for the mass of milk thus transported.

Description

Method and device for recording quantities during milk acceptance using mobile or stationary acceptance systems

The invention relates to a method for quantity detection during milk acceptance with a mobile or stationary acceptance system, in which a quantity of milk to be transferred via a transfer path from a first container to a second container is recorded and quantified via its volume, and a device for carrying out the method according to the preamble of claim 9.

The task of collecting quantities when receiving milk with mobile acceptance systems, so-called milk collection vehicles, or stationary acceptance systems, is to accept quantities from a first container, for example a delivery container from a supplier, and to transfer them to a second container, for example a collecting tank. In the case of methods of the generic type, the volume of the transferred milk is determined by its volume and the mass of the transferred milk is calculated from the density of the degassed milk. So that the mass of the transferred amount of milk can be determined - the milk quality regulation stipulates that the milk mass and not the volume is to be paid to the supplier - the liquid volume flow that enters the measuring system and is mixed with the gaseous components, especially air may be to completely degas or vent and only then determine volumetnch. The separated air results almost exclusively from the air that enters the measuring system during milk intake, especially milk at the start of milk transfer and snorkeling at the end of milk transfer, and only to an extremely small extent from air, which are small and tiny air bubbles is deposited in the milk of the delivery container. Desorption of milk dissolved in air is not sought; however, it cannot be prevented under certain procedural conditions (vacuum operation). Known measuring systems are equipped with a control system, the task of which is then, among other things, to master special cases and also improper handling of the system in addition to a 'normal' milk intake. This includes, for example, arbitrary air snorkeling during the take-over, intentional or unintentional temporary closing of the acceptance line on the intake manifold and suction from several containers of a supplier with breaks of different lengths when changing from one container to another. In addition, the measuring system should be easily adaptable to different suction conditions (suction height and / or hose length) in terms of control and regulation technology and in any case quickly find a stable operating point without instabilities.

The measuring systems which have become known so far and which are either designed as so-called pump systems (cf. for example DE 24 37 306 A1; DE 3440 310 A1) or vacuum systems (cf. for example DE 25 10 966 A1; DE 40 07 914 A1) work over the duration of milk acceptance with an essentially constant acceptance performance, which is determined by the design of the pump or vacuum system. It should be noted that the acceptance performance has increased to 30,000 l / h in recent years, in some cases even more, whereby the so-called air separator container of the measuring system is a component that limits its maximum acceptance performance. The air separator containers known today separate the air bubbles contained in the milk from the milk mainly by buoyancy and subsequent separation via the free liquid surface and only to a small extent by separating and separating the air bubbles in the centrifugal field of a rotating milk flow in the air separator container. Therefore, when designing known air separator containers, care is taken to ensure that the lowering speed of the milk in the container is slow compared to the rate of ascent of the air bubbles. This is achieved by the longest possible residence time of the milk and thus the air bubbles contained in the milk in the air separator container, the residence time being determined by the liquid-filled volume of the air separator container for a given acceptance performance. So there is a large dwell time inevitably results in a large container cross section, since a container configuration with a large overall height compared to the container diameter increases the separation path and thus adversely affects the separation performance. Since the space available, in particular on a milk collection truck, is limited in all directions, there are natural limits to increasing the dimensions of the air separator container. This also limits the increase in acceptance performance by enlarging the air separator container, if you do not want to run the risk that the measurement result with regard to the volume transferred during milk acceptance will be falsified by entraining air bubbles in and through the volume counter. Known measuring systems limit the acceptance performance to a maximum value, with which even difficult suction conditions (air suction when milk production is interrupted) can be mastered. With this permissible acceptance performance, the measuring system and especially the air separator tank are under-challenged with favorable or normal suction conditions, so that there is an unused power reserve under these suction conditions.

An air separator, as is known, for example, from DE 2437 306 A1 or DE 25 10 966 A1, can at best cover the lower performance range of acceptance powers required today, and only if favorable operating conditions are present. In order to master higher acceptance rates, there has been no shortage of attempts to improve the air separation in the air separator tank, which is a limiting element in terms of increasing the acceptance rate, without resorting to the constructive means of further enlarging the air separator tank. An Indian

Air separator container described in DE 41 11 280 A1 tries to solve the problem by reducing the flow velocity of the milk flowing into the air separator container immediately before it enters the same. For this purpose, it is proposed that a bluff body designed as a stopper with a plurality of parallel channels be preceded by the inlet connection together with a funnel widening to its cross section. The result is to be achieved with the known air separator container that the Milk measuring system can be operated with a higher throughput without the milk having a higher proportion of the air inclusions than in conventional systems at this higher output or without having a lower proportion of air inclusions with the same throughput. The measures proposed above are problematic because they also create flow resistances on the one hand and cleaning problems on the other hand due to the extremely enlarged surfaces exposed to the liquid

Other measures known from DE 40 07 914 A1 aim to further reduce the mixing in of air when filling the air separator in order to be able to increase the acceptance performance to a limited extent. This is to be achieved in that the air separator at least one other inlet is provided which is offset from the one inlet, and that all inlets are equipped with shut-off valves which are controlled by a control device which responds to the milk level in the container in such a way that when the level rises from the lower inlet to the next higher inlet etc. and reversed when the level falls It is obvious that the proposed measures are only suitable to optimally utilize the maximum dwell time determined by the maximum volume of the air separator container as often as possible.It is not recognizable how the known system increases the assumption performance beyond its maximum acceptance performance determined by the dwell time, if there is also the risk of large air ingress

With regard to the separation and separation of gas or air admixtures, the known air separator containers are subject to basic flow-physical limits, which are all the lower and to which it is more difficult to approximate, the colder and more viscous the carrier liquid milk for the gas bubbles and the more finely divided the gas admixtures are. It has therefore also been proposed (cf. for example DE 35 45 160 A1) that the quantity acquisition, in particular of milk, is carried out directly via the milk mass and not via to carry out the volume of transferred milk. This is achieved in that the total or part of the milk quantity to be transferred is or are successively transferred to a measuring container and the mass of the milk quantity presented in this measuring container is determined gravimetrically. With this method, there is no need to degas or deaerate the amount of milk, since any gas or air bubbles dissolved in the milk play practically no role due to the density differences between gas and their carrier liquid by three orders of magnitude. The aforementioned so-called weighing systems usually work batchwise and therefore discontinuously when the amount of milk to be transferred is relatively large. High acceptance rates cannot therefore be achieved with sufficient accuracy because enlarging the measuring container (tare mass) inevitably leads to an enlargement of the measuring error. In addition, measuring systems of this type have so far not been cost-competitive with the methods and devices of the generic type.

The disadvantages with which the above-mentioned weighing system is afflicted, for example, are avoided if another known method for determining the mass of a quantity of milk flowing through a flow line is used in the course of milk acceptance (DE 195 07 542 C1). In this method, a partial flow proportional to the quantity is branched off and collected from a total flow of the quantity of milk to be transferred in order to obtain a sample quantity representative of the quantity of milk to be transferred. After the transfer of the milk quantity has ended, the mass of the partial quantity resulting from the partial flow is determined gravimetrically and the mass of the total quantity of milk transferred is determined using a known, arrangement-specific proportionality factor which determines the ratio between partial and total flow. This process depends on the representativeness of the sample amount obtained in relation to the total amount of milk to be transferred, both in terms of the proportionality of the amount and in relation to the ratio between milk and air admixtures. Experience has shown that a constant determining the relationship between partial and total flow Proportionality factor over the entire acceptance time is very difficult to implement in the event of changing operating and acceptance conditions.

It is also known to continuously measure the density of a liquid fermentation substrate in the fermentation tank outside of the same in a bypass line (DE 44 29 809 A1), the density being determined by means of an ultrasound density measurement.

Furthermore, in the German magazine "measure, test, automate", December 1985, pp. 676-681, it is described how an operational flow measurement of liquids in closed pipelines can be carried out by means of ultrasonic flow measurement technology (transit time method or Doppler method) "Contactless", ie without additional disturbing installations in the flow. The ultrasonic flow measurement enables the measurement of non-conductive liquids. Disturbances in the flow profile, which could impair the measurement, are largely reduced by compensation methods - multichannel measurement.

It is an object of the present invention to design the quantity detection in a method of the generic type without the limiting influence of an air separator.

In terms of process engineering, the object is achieved by the features of claim 1. Advantageous embodiments of the method are the subject of further subclaims. A device for carrying out the proposed method is realized by the features of subsidiary claim 9, while advantageous embodiments of the proposed device are the subject of further subclaims.

In the proposed method, there is no gas or gas. Remove air admixtures from the amount of milk to be transferred. Instead, the knowledge is used that the speed of sound of UI- ultrasound pulses that have proven to be particularly informative are different in an air / milk mixture than in deaerated milk. By dividing the flow into a main and a secondary flow, the possibility is created of freeing the secondary flow, which can be kept so small that a reference measurement in deaerated milk is still possible, of air admixtures, so that the main is sonicated - and the side stream a significant signal on the one hand for a possibly present milk / air mixture and on the other hand there is a reference signal for deaerated milk. Since the speed of sound is fundamentally temperature-dependent, at least the temperature in the main stream must be measured. From the respective sound propagation time in the main flow and that in the secondary flow, the reference flow, and using the speed of sound in air as a function of the temperature in the main flow, a current milk fraction φ (t) in the main flow can now be calculated continuously with the corresponding assignment of the measured values obtained. In an acceptance time t _A required for the transfer of the total milk quantity, the milk volume V which then passes through the defined location of the transfer path is then determined from the respectively continuously determined milk components φ (t) and the values associated therewith of the flow physical quantity which characterizes the flow at the defined point of its transfer path _M o of the transferred amount of milk (pure liquid phase) determined.

The flow-physical quantity characterizing the flow at the defined point can be, for example, the mean flow velocity in this passage cross-section, which is continuously and easily determined, for example, using a flow meter, as has also hitherto been done in known methods. Since the passage cross-section Ao at the defined point of the transfer path is known, the milk volume V _M o passed through this passage cross-section in the acceptance time t _{A is} determined according to equation (1) to t _A

VMO = An J φ (t) Vmittelo) dt. (1 )

O The current milk percentage (t) (derivation see below) is calculated according to equation (2)

1 φ (t) = {1 - 2α [1 - ß] - ß ² }. (2)

M - «l ²

using the abbreviations A = A _L1 (T I) / a _M ι (T I) = a _L ι (T I) (T ₂ / T) / (d _2/1 ₂₎ (2a)

3 = a _L1 (T ₁ ) / (dι / tι) (2b)

As equation (2) shows, for an exact determination of the milk fraction <p (t) is the measurement of the temperatures

and T _{2 of} the milk in the sonicated main and secondary flow required. In addition, the speed of sound a ₁ (T-ι), which is dependent on the temperature T ^ in the main flow, must be provided in each case. Furthermore, for the known sound path d- _\ in the main stream (milk / air mixture), a sound run time required for this and for a likewise known sound path d ₂ in the secondary flow (deaerated milk), a sound run time t ₂ required for this is continuously measured. If the temperatures Ti and T _{2 are the} same, which is usually the case to a good approximation, all that remains is the measurement task of continuously determining the temperature Ti of the milk / air mixture in the main stream.

In order to achieve the same flow conditions with regard to turbulence and thus comparable conditions for the bubble distribution, the bubble quality and size, it is further proposed that the Reynolds number of the main stream and that of the flow from which the main stream emerged after division are essentially the same.

Since the transmission is limited to a diametrical section of the main flow, it cannot be ruled out that the measurement result for the sound propagation time in the main flow will be influenced by at least theoretically possible separation movements of the air bubbles in their carrier liquid (e.g. concentration of the swarm of bubbles in certain areas). Therefore the pre made a stroke that the air bubbles contained in a passage cross section of the main stream in the latter are distributed substantially uniformly over this passage cross section, the distribution, viewed in the direction of flow, taking place before the transmission

The venting of the side stream is particularly efficient if, as is also provided, this is done by the separating action of a centrifugal force field. According to a first proposal, this can be done by applying the energy for generating the centrifugal force field from the flow energy of the side stream and according to a second proposal by external energy that is discharged into the secondary flow from the environment

With a view to the implementation of a relatively simple method, it is further provided that at the point where the flow is divided into the main and secondary flows, the latter is branched off in an amount dependent on the back pressure of the flow at the point of the division in order to achieve the division of quantity, and in addition it serves to supply the secondary flow with the electricity energy necessary for its further treatment

The use of the proposed device for carrying out the method according to the invention is independent of whether there is a so-called pump or vacuum system. The only important thing is that the transfer line is behind the first section, in which there is a measuring device for determining the mean in the transfer line Flow rate or one of these proportions is located in a second section, a bypass line branches in this is a separator for separating gas from its carrier fluid, in the present case of air from a milk / air mixture, both in the first section and Also in the bypass line, as seen in the direction of flow, an ultrasound device is arranged behind the separating device, each of which consists of a transmitter and a receiver exists and each serves to transmit a characteristic and known sound path. Temperature measurements in the main and secondary flow, preferably in a plane in which the sound path lies, on the one hand is the computational correction of the temperature-dependent sound velocities in the Main flow (separate for liquid and air) possible, which can not be measured separately from each other there, and on the other hand, the reference measurement in the secondary flow can be corrected depending on the temperature. The temperature-dependent sound velocity a ι (Tι) is stored in a data memory , which is connected to a computer and control unit, in which all measured values obtained with the proposed device are processed

The separating device is particularly simple and particularly efficient in terms of separation technology if it is designed as a centrifugal separator with a tangential inlet and outlet in order to intensify the separating effect of the centrifugal force field either because the energy of the secondary flow is insufficient or because the driving forces of the separation process are forced If it is desired, a further ¹ nn is proposed to additionally equip the centrifugal separator with a drive to support the rotational flow

It is also envisaged, in the second section of the transfer line and in the direction of the flow, to arrange a mixing device in front of the first ultrasound device. This measure ensures that random segregation between milk and air bubbles, for example by coagulation of bubbles, leads to inhomogeneities in the plane of the pass-through cross section for the main flow can be recorded in a non-representative manner as a random result in the sound path or not recorded. So-called static mixers have proven to be particularly effective and simple in this connection

The division of the flow into the main and secondary flow is particularly simple if the flow entry into the bypass line acts as a flow divider is in the form of a pitot tube. In order to increase the representativity of the secondary flow in comparison to the main flow, it is further provided that the flow divider accesses the entire passage cross section of the first section of the transfer line.

A flow-physical quantity which reliably and precisely characterizes the flow at the defined point of the transfer path is, as is also provided, obtained in that the measuring device is designed for its determination as a volume counter and / or flow meter.

An embodiment of the invention is shown in the drawing and is explained below according to structure and function. 1 shows a device in a highly simplified and schematic form for carrying out the proposed method and FIGS. 2 and 3 show sketches of the underlying models for the quantitative detection of the sound path in the milk / air mixture (main stream) or in deaerated milk (secondary stream) serve to explain the calculation of the milk component φ (t).

FIG. 1 shows a section of a transfer line 3 in which a first section 3a is shown on the left-hand side, followed by a second section 3b and finally a third section 3c. Arranged in the first section 3a is a measuring device 6 for determining a flow-physical quantity which characterizes the flow in the first section 3a, for example the mean flow velocity. The passage cross-section detected by the measuring device 6 bears the reference symbol 0. The part of the transfer line 3 shown is flowed through by an inlet E in the direction of an outlet A. After the first section 3a, as seen in the direction of flow, the transfer line 3 branches into the above-mentioned second section 3b and a bypass line 4. An upstream bypass line 4b opens tangentially into a separating device 5, while a downstream bypass line 5 Line 4c tapers tangentially from this and is returned to the second section 3b of the transfer line 3. The flow entry into the Byoass line 4 is designed as a flow divider 4a in the form of a pitot tube. The second section 3b accommodates a first ultrasound device 7, which consists of a There is a transmitter 7a and a receiver 7b arranged diametrically on the other side of the second section 3b. In the same arrangement, there is a second ultrasound device 8 in the bypass line 4, seen in the direction of flow, behind the separating device 5, likewise consisting of a transmitter 8a and a receiver 8b In the second section 3b, viewed in the direction of flow, a mixing device 9 is arranged in front of the first ultrasound device 7, which is preferably designed as a static mixer

The plane of the passage cross section of the second section 3b, in which the transmission is carried out with the first ultrasound device 7, bears the reference numeral 1. The plane of the passage cross section of the downstream bypass line 4c, in which the transmission is carried out with the second ultrasound device 8 the reference symbol 2 is used. The measured values obtained in the mean cross-sections 0, 1 and 2 and further variables assigned to the pass-through cross-sections are each indicated below with the corresponding level designation

A device for measuring the temperature 12 or 13 is provided in the cross-sectional plane 1 and 2. The measuring device 6, the ultrasound devices 7 and 8 and the devices for measuring the temperatures 12 and 13 are connected to a computer and control unit 10 which is connected to a data memory 11 for reading in and reading out data, necessarily the speed of sound in air a _u (Tι) which is dependent on the temperature Ti in the main stream

At the inlet E, if air is sucked in during milk acceptance, a milk / air mixture occurs which forms a flow in the first section 3a, one of which characterizes the flow physics size by means of the measuring device 6 is continuously recorded. The latter is preferably designed as a volume meter and / or flow meter; from the respective measured variable can then, for example, continuously the current average flow velocity v _{mιr [e} ιo in the passage cross-section _A. be determined. A volume flow of the milk / air mixture Q _M / _LO is divided behind the measuring device 6 into a main flow Q _{M L1} and a secondary flow Q _M / _2. The latter, in the form of a milk / air mixture in front of the separating device 5, is then freed of air admixtures in the separating device 5 and reaches the downstream bypass line 4c as a milk flow Q _M 2. The main flow Q _M / u (milk / air mixture) is continuously subjected to ultrasound pulses in the first ultrasound device 7 and transmitted through it, and the sound propagation time t required for the present sound path di is measured. The milk flow Q _M2 undergoes a comparable transmission through the second ultrasound device 8. A sound path d _{2 is} provided here, and the sound time t ₂ required for this is also measured. All measured values (the mean flow velocity v-nn _te i _. , The sound propagation times ti and t ₂ and the temperatures Ti and T ₂ ) are brought together in the control and computer unit 10 and together with the speed of sound a _L ι (Tι) in the main flow to during the acceptance time t _A the milk volume V _M o penetrating the passage cross section Ao of the transferred amount of milk (pure liquid phase) according to equation (1)

VMO = An ( ⁽ J ⁾ (t) Vmüt ioft) dt (1) o processed. It is assumed or desirable that the respective bubble distribution in the passage cross sections Ao and i is homogeneous and correspond to each other and thus the milk fractions φ (t) in these mean cross sections are the same.

The formula symbols used in equations (1) and (2) and the quantities to be used for the derivation have the meaning shown in the following list: Shape characters physical size

d Sound path / tube diameter / characteristic cross-sectional dimension s overall sound path

SM in milk

S in air

A total passage cross section

A _M milk cross-section (total)

AL bubble cross-section (total)

T Temperature φ milk fraction (volume of air-free milk based on the volume of the milk / air mixture in the flow area under consideration: φθ = Φ1 = Φ = V OA M / LO = V _M lA / _M / L1 ψ one-dimensionally measured milk fraction ψ = s _M ι dι

Vmean flow rate

Q volume flow

QM / L milk / air mixture

V volume

VM / 1_ milk / air mixture

V _M deaerated milk t signal runtime

Acceptance time a Speed of sound a = f (T) aM in milk a _L in air aM L in milk / air mixture

0,1,2 indices for the positions 0, 1, 2 The volume V _M o determined according to equation (1) represents the volume of the air-free milk which flows through the average cross-section Ao in the form of a milk / air mixture in the acceptance time t _A. Equation (1) is the milk fraction determined according to equation (2) <p (t) a time-dependent variable in the general case, since it is determined by the air content of the milk, which is generally time-variable, and the temperature Ti, which is variable in time, in the main flow. Seme Derivation is briefly outlined below

The average velocity v _mrt t _e ιo (t) is generated by the measuring device 6 in the average cross section Ao. Di is the total sound path in the average cross section Ai, and ti is the sound propagation time for this sound path. The value di / ti thus represents the average speed of sound in the milk / air mixture in the average cross-section Ai

Since the speed of sound for milk a _M1 in the cross-sectional area Ai cannot be determined there by means of a transit time measurement, since air is added to the milk, a reference measurement for this sound speed a _M ι in the cross-section A _{2 of} the bypass line 4 is carried out promptly 3) a _re f ⁼ 3.M2 ⁼ SM2 / 1 ₂ = d _2/1 ₂ (3)

For the same temperatures T ₂ = Ti in the passage cross sections A1 and A ₂ can

3MI = 3 2 (4) can be set

If the temperature is not the same (T ₂ ≠ Ti), a _M ι is calculated from a _M2 and the temperature ratio V (Ti / T ₂ ) and the evaluation via

based on

The speed of sound a _u in air is also temperature-dependent (a _u = f (T)). It is to be stored in the data memory 11 as a function of the measured temperature Ti or T ₂ , from which it can be read in each case The two sound propagation times ti and t ₂ (ultrasound devices 7 and 8), at least one of the temperatures Ti or T ₂ (measuring devices 12 and 13) and the average speed v _mrtte ι ₀ (measuring device 6) are thus to be measured

With a view to FIG. 2, the sound propagation time ti in the average cross section Ai is calculated as ti = s _M ι / a _M ι + s _L ι / a _L ι (2 1)

The calculation is based on the assumption that the one-dimensionally exposed area of the main flow is representative of the entire average cross-section Ai. In case of doubt, the proposed mixing device 9, arranged before the through-sectional area A-ι, can sufficiently ensure the above assumption. The entire sound path di settles thus according to equation (2 2) together from the distances s _M1 in milk and s _u in air

and with the flow rate

Vmrttel M1 ⁼ Vmrttel L1 ⁼ mλtel (2 3) also results in the volume flows and thus the volumes of milk and air. in the average cross section Ai Since the flow and bubble distribution ratios in the cross sections Ai and Ao are almost identical, the situation in the average cross section Ai can be used to deduce the volume flows and thus the volumes of milk and air in the average cross section Ao of the transfer line 3

With

and k di = Ai = k (S -I + SM) (with k as the proportionality factor) (2 5) where from equation (2 5) after transformation equation (2 5a) results 1 - (SM lά <) ² = ( SMI / di) ² + 2 SMI SM / di ² (2 5a) and with the one-dimensional milk fraction anteil (t), measured over the first Ultrasound device 7 in the cross section Ai,

Equation (2.1) results in tι = dι [u / a _Mi + (1 - v | /) / a _L ι]. (2.1a)

With the definition of the milk fraction <p (t) according to equation (2.7)

is obtained taking into account equations (2.4) and (2.5a) for the milk fraction φ (t) according to equation (2.7a) φ (t) = A _M1 / AI = 1 - Au Ai = 1 - (s ₁ / di) ² = (s _M1 / di) ² + 2 s _M1 s _L1 / di ² =

= (s _M1 / d) ² + 2 s _M / di (1 - SI / di) (2.7a) and thus the relationship between the milk fraction φ (t) and the one-dimensional milk fraction ψ (t) according to equation (2.6) Equation (2.8)

The milk fraction o (t) is finally obtained taking into account equations (2.1) to (2.8) and equations (3) and (5) according to equation (2)

1 φ (t) = {1 - 2α [1 - ß] - ß ² }. (2) r 1 - l ²

using the abbreviations = a _u (T / a _M ι (T I) = a _L1 (T I) (T ₂ / Ti) / (d _2/1 ₂₎ (2a) ß = a _L1 (T ₁₎ / (dι / tι). (2b)

Claims

claims

1 Method for recording quantities in milk acceptance using a mobile or stationary acceptance system, in which a quantity of milk to be transferred via a transfer route from a first container to a second container is recorded and quantified via its volume, characterized in that

• that the quantity of milk forms a flow at a defined point on its transfer path, from which the mean flow velocity or a quantity proportional to it (volume flow Q or volume V transferred in the time interval) is measured continuously, • that the flow is then divided into one Main and one

Sidestream,

• that the side stream is freed of air admixtures,

• that the main and the vented side stream are continuously subjected to ultrasound pulses and transmitted through and the respective sound propagation time and at least the temperature in the main stream are measured,

• that the respective current average sound speed of the milk / air mixture flowing there is determined from the sound propagation time in the main flow and the respective current average sound speed of the deaerated milk flowing there is determined in the secondary flow,

That a current milk fraction φ (t) in the main flow is calculated from these two speeds of sound and the speed of sound in air at the assigned temperature of the main flow,

• and that in an acceptance time t _A required for the transfer of the total milk quantity from the respective milk fractions φ (t) and the mean flow rate assigned to them at the defined point of the transfer path or a size proportional to this, the total milk volume penetrating the defined point of the transfer path V _M o of the transferred amount of milk determined

2. The method according to claim 1, characterized in that the defined point of the transfer path in the acceptance time t _A penetrating milk volume V _M0 according to equation (1) t _A

5 V _M0 = Ao f φ (t) V _rn _ _te κ> (t) dt (1) o is determined, the current milk fraction φ (t) according to equation (2)

1 φ (t) = {1 - 2α [1 - ß] - ß ² }, (2)

IO [1 - α] ²

using the abbreviations = a _L1 (Ti) / a _M1 (Ti) = a ₁ (Ti) V (T ₂ / X,) / (d _2/1 ₂ ) (2a) ß = au (T ₁ ) / ( dι / tι) (2b)

15 calculated with

A passage cross section Ao at the defined point of the transfer route,

A continuously measured mean flow velocity v _mrtt eio at the defined point on the transfer path,

20 • a sound path di in the main stream and a required sound path ti measured continuously for this,

A sound path d ₂ in the secondary flow and a required sound path t ₂ measured continuously for this,

Continuously measured temperatures Ti and T ₂ in the main and secondary flows,

• with the speed of sound in air a (Tι) and

• With the speed of sound in milk a _M ι (Tι) depending on the temperature Ti in the main flow. A method according to claim 1 or 2, characterized in that the

Reynolds number of the main stream and ιeπe of the flow from which the main stream emerged after division are essentially the same

Method according to one of claims 1 to 3, characterized in that the air bubbles contained in the cross-section of the main stream in the latter are distributed substantially uniformly over this cross-section, the distribution, viewed in the direction of flow, takes place before the transmission

Method according to one of claims 1 to 4, characterized in that the bypass is vented by the separating action of a centrifugal force field

Method according to Claim 5, characterized in that the energy for generating the centrifugal force field is applied from the flow energy of the secondary flow

A method according to claim 5, characterized in that the energy for generating the centrifugal force field by external energy, which from the

Environment is introduced into the bypass, is applied

Method according to one of claims 1 to 7, characterized in that, at the point of division of the flow into the main and secondary flows, the latter is branched off in an amount dependent on the back pressure of the flow at the point of division

9. Device for carrying out the method according to one of claims 1 to 8, with a transfer line leading from a first to a second container, in which a measuring device for determining the average flow velocity present in the transfer line or a variable proportional to it is arranged, characterized,

• that the measuring device (6) is arranged in a first section (3a) of the transfer line (3),

• that, seen in the direction of flow, the transfer line (3) behind the first section (3a) into a second section (3b) and one

Bypass line (4) branched,

That a separation device (5) is provided in the bypass line (4) for separating air from a milk / air mixture,

• That in the second section (3b) a first ultrasonic device (7) and in the bypass line (4), seen in the flow direction, behind the

Separating device (5) a second ultrasonic device (8) are arranged, each consisting of a transmitter and a receiver (7a, 7b or 8a, 8b) and each for the transmission of a characteristic and known sound path (di, d ₂ ), That a device for measuring the temperature (12) is provided at least in the second section (3b),

• and that the measuring device (6), the ultrasound devices (7 and 8) and the devices for measuring the temperatures (12 and 13) are connected to a computer and control unit (8) on which a data memory (1 1) is connected for reading in and reading out data.

10. The device according to claim 9, characterized in that the separating device (5) is designed as a centrifugal separator with tangential inlet and outlet. 11 Device according to claim 10, characterized in that the centrifugal separator (5) is additionally equipped with a drive for supporting the rotation flow.

5 12. Device according to one of claims 9 to 11, characterized in that in the second section (3b) of the transfer line (3) and seen in the flow direction, in front of the first ultrasound device (7) there is a warning light (9) is.

13 device according to claim 12, characterized in that the mixing device (9) is designed as a static mixer.

14 Device according to one of claims 9 to 13, characterized in that the flow entry into the bypass line (4) as a flow divider (4a) in

15 shape of a pitot tube is formed.

15 Device according to claim 14, characterized in that the flow divider (4a) accesses the entire cross-sectional area of the first section (3a)

20th

16. Device according to one of claims 9 to 15, characterized in that the measuring device (6) is designed as a volume meter and / or flow meter.