GB2534427A

GB2534427A - Apparatus and method for dry silo volume measurement

Info

Publication number: GB2534427A
Application number: GB1501266.9A
Authority: GB
Inventors: Mcpherson Gregory
Original assignee: Pneutrol Int Ltd
Current assignee: Pneutrol Int Ltd
Priority date: 2015-01-26
Filing date: 2015-01-26
Publication date: 2016-07-27
Also published as: GB201501266D0

Abstract

An apparatus and method are disclosed for determining the amount of material remaining in a dry silo 1 that is in communication with a mixing device 2. The apparatus comprises a control unit, a first sensing means operable to sense the position of an outlet valve of the silo, and a second sensing means operable to measure the current of a mixing screw motor of a mixing device associated with the silo, wherein the sensing means are in communication with the control unit, and wherein the control unit is configured to monitor measurements of electrical current from the mixing screw motor to determine the operational status of the mixing screw and is configured to measure the run time of the mixing screw motor at the measured electrical current in order to measure the amount of material passed through the mixing screw.

Description

APPARATUS AND METHOD FOR DRY SILO VOLUME MEASUREMENT

Field of the Invention

The present invention relates to a sensor apparatus and method for measuring the level or volume of material in a dry silo.

Background of the Invention

Silos for the storage of bulk material such as cement, sand and dry mortar are well known. Silos containing dry mortar are most commonly seen on construction sites and are generally identifiable as large cylindrical vessels having a generally conical lower section and which are elevated above ground level by support legs. Such silos are often mobile silos which are delivered as full containers to a site on the back of a specially adapted vehicle which has the ability to deploy the silo from a transport position on the vehicle, to an upright position at the site. Once empty of its contents, the silo can be taken away for refilling before redeployment. Alternatively, the silo can be refilled on site from a bulk tanker.

At the lower end of the dry mortar silo there is provided an outlet valve, usually a butterfly valve, which is operable to allow the mortar to fall under gravity from the silo. The dry mortar falls into a mixing unit, which comprises a motor powered feeder or mixing screw. Upon activation of the mixing unit, water is also introduced to the mixing unit from a separate water source and the mixing screw is rotated so that the dry mortar and water are mixed. Power for the mixing screw is provided by an electric motor. The resulting wet mortar mixture is discharged from the mixing unit in the required amounts and gathered in a tub or bucket ready for use at the site.

The amount or level of material remaining in a silo can be estimated in a number ways. In one method, the sides of the silo can be tapped by an operator, whereby a change in sound is indicative of the level within the silo. This method relies heavily on the judgement of the person tapping the silo and does not provide a quantitative measure of the amount of material remaining in the silo.

In another method, a manual count of the number of tubs of mortar produced from the silo can be made, with each 0.25m3 tub being roughly equivalent to approximately 340kg of mortar. In this way, a rough approximation of the amount of material used can be made. This method relies on accurate record keeping of the number and type of containers of wet mortar obtained from the mixing unit, and also requires that each container type is filled with a uniform amount each time. On a busy building site such requirements are difficult to meet and there is great scope for human error to affect the accuracy of any measurement made.

In another method, the weight of the silo can be measured, for example by lifting, and the measured weight deducted from the original weight of the full silo to provide an indication of remaining material. This method suffers the drawback of having to interrupt the use of the silo and having to disconnect ancillaries such as water and electrical connections, as well as requiring a crane or other suitable lifting apparatus and a means, such as a load cell, to measure the weight In another method, a level indicators can be used to provide point levels for each position to where they are fitted, normally a high and low levels. This method provides limited information as it is not possible to tell at what level the material is at when the indicators are not activated.

In another method a continuous level monitor can provide an indication of a particular level within the silo. There are various types of continuous level indicators available. Examples of which include ultrasonic, radar and mechanical lowering devices to make contact with the material and measure the distance travelled. Each method has advantages and disadvantages but the challenge with bulk powder level measurement is due to the uneven surface level at the top of the product. When the silo is filled, the material tends to settle into an inverted "V" form, whereas when material is discharged the material surface level forms a "V" formation. Many continuous level systems suffer errors due to the uneven nature of the material within the silo and continuous level probes are generally expensive products due to the technology involved.

It is therefore an object of the present invention to mitigate the disadvantages of the prior art and to provide an improved, cost effective means for measuring the level or volume of material in a dry silo.

Summary of the Invention

Accordingly, in one aspect of the present invention there is provided an apparatus for determining the amount of material remaining in a silo that is in communication with a mixing device, the apparatus comprising: a control unit; a first sensing means operable to sense the position of an outlet valve of the silo, the position of the valve being either opened or closed; a second sensing means operable to measure the current of a mixing screw motor of a mixing device associated with the silo; wherein the first and second sensing means are in communication with the control unit, and wherein the control unit is configured to monitor the measurements of electrical current to determine the operational status of the mixing screw and is configured to measure the run time of the mixing screw motor at the measured electrical current.

Preferably, the material is dry mortar.

The operational status of the mixing screw being either stopped, mixing or in a wash-out cycle.

It will be appreciated that the term outlet valve comprises any suitable closure means selectively operable to allow to flow of material from the silo, and to prevent the flow of material from a silo. Examples of such a valve include a butterfly valve, or a discharge door.

Optionally, the first sensing means comprises one or more microswitches.

Optionally, the first sensing means comprises one or more proximity sensors.

Optionally, the second sensing means is operable to obtain the mixing screw motor electrical current from a contactor associated with the mixing screw motor.

Optionally, the second sensing means is operable to obtain the mixing screw motor electrical current from a variable speed drive associated with the mixing screw motor.

Optionally, the second sensing means comprises a current transducer.

Optionally, the current transducer is connectible between the control unit and the contactor.

Optionally, the current transducer is connectible between the control unit and a supply cable to the variable speed drive.

Optionally, the second sensing means is further operable to obtain measurement of frequency of the mixing screw motor.

Optionally, the second sensing means comprises a communication or "comms" cable connectible between the control unit and a variable speed drive associated with the mixing screw motor.

Optionally, the control unit is a control module comprising a memory.

Optionally, the control module is located proximate the silo in use.

Optionally, the control module comprises a user interface.

Optionally, the control module comprises a display.

Optionally, the control module comprises location identification means.

Optionally, the apparatus comprises a temperature sensor.

Optionally, the control unit or control module is located remote from the silo in use, wherein the sensors are in remote communication with the control module.

In accordance with a second aspect of the invention, control unit or control module, and/or first and second sensing means are optionally adapted to communicate with a remote server, the server being accessible via a plurality of user devices to enable a number of remote users to access the data stored on the server to monitor the location and status of the apparatus and to review the amount of material remaining in the silo.

In this way, the apparatus comprises a system whereby users can remotely review in real time or near real time the status of a silo or plurality of silos, and mixing device (s) associated with said silo(s).

Optionally, the server is a cloud based server.

Conveniently, the apparatus is remotely controllable by users. Optionally, remote control may be activated by having access via the server, or via SMS messaging.

Conveniently, software or suitable program running on the server and/or user devices in communication with the server is adapted to calculate and predict when a silo should be replenished or replaced based on usage rates and material remaining in the silo.

Conveniently, the software or suitable program running on the server and/or user devices in communication with the server is adapted to provide a graphical trend of the silo material level over a selectable time period.

Optionally, the software or suitable program running on the server and/or user devices in communication with the server is adapted to interface with third party accounts systems to automatically order and receive material delivered to a silo or silos comprising the apparatus of the invention.

Optionally, the software or suitable program running on the server and/or user devices in communication with the server is adapted to compile a range of reports relating to mortar production and deliveries over a selectable time period.

Optionally, the software or suitable program running on the server and/or user devices in communication with the server has the means for receiving data inputted by users, said data comprising service interval data for the mixing device, so that users of said apparatus can be alerted when a service interval has been reached or is approaching.

Optionally, the software or suitable program running on the server and/or user devices in communication with the server is adapted to provide users with operational data for fault finding. For example, data provided from the apparatus can enable users to remotely verify that appropriate wash-out or purge cycles are being undertaken according to guidelines set. For example, the number and duration of wash-out cycles can be recorded and presented. In this way, failure to wash out and maintain the mixing device can be identified. Furthermore, the mixing screw motor current can be measured when the mixing screw is running empty and compared with previous readings when running in a similar state to indicate any increased load on the motor which would be indicative of build-up of material on the mixing screw or outer casing, due to inadequate cleaning or maintenance. Furthermore in conjunction with temperature measurements, users can be alerted to the requirement of appropriates cleaning cycles in excessively hot or cold weather.

In a third aspect of the present invention, there is provided a method of determining the amount of material remaining in a silo, the method comprising the steps of: sensing the position of an outlet valve of the silo, the position of the outlet valve being either opened or closed; (ii) measuring the electrical current of a mixing screw motor of a mixing device associated with the silo; (iii) determining the speed of rotation of the mixing screw; (iv) determining whether the mixing screw is (a) in a mixing cycle, or (b) in a wash-out cycle; (v) when the mixing screw is in a mixing cycle, measuring the duration of the mixing cycle; (vi) calculating the amount of material mixed by mixing screw during the mixing cycle based on the measurements of (iii) and (v) and known values for the amount of material mixed by the mixing screw over a given time period at a given screw speed; (vii) calculating the amount of material remaining in the silo by deducting the amount calculated in (vi) from the known total starting amount of material in the silo, or from a previously calculated amount of material remaining in the silo.

Optionally, the step (Hi) of determining the speed of rotation of the mixing screw is effected by measuring the mixing screw motor frequency to determine the speed of rotation of the mixing screw.

Optionally, the method comprises the further step (viii) of saving the value calculated in step (vii) in a memory.

Optionally, the method comprises the further step (ix) of measuring the ambient temperature.

Optionally, the method comprises the further step (x) of transmitting the data obtained from any of steps (i) to (ix) to a remote or cloud based server in accordance with the second aspect of the invention.

Optionally, the steps (iii) to (vii) are performed by appropriate software or program running on a remote or cloud based server, or user devices in communication with said remote or cloud based server.

In a fourth aspect of the invention there is provided a kit of parts, wherein the kit includes a first sensor, a second sensor, and a control unit; wherein the first sensor is configured to sense the position of an outlet valve of a silo, the position of the outlet valve being either opened or closed, wherein the second sensor operable to measure the electrical current of a mixing screw motor of a mixing device associated with the silo; wherein the first and second sensors are in communication with the control unit, the control unit being adapted to monitor the measured electrical current and the run time of the mixing screw, wherein the electrical current is indicative of the operational status of the mixing screw.

The various aspects of the present invention can be practiced alone or in combination with one or more of the other aspects, as will be appreciated by those skilled in the relevant arts. The various aspects of the invention can optionally be provided in combination with one or more of the optional features of the other aspects of the invention. Also, optional features described in relation to one example or aspect can optionally be combined alone or together with other features in different examples or aspects of the invention.

Various examples and aspects of the invention will now be described in detail with reference to the accompanying figures. Still other aspects, features, and advantages of the present invention are readily apparent from the entire description thereof, including the figures, which illustrate a number of exemplary aspects and implementations. The invention is also capable of other and different aspects and implementations, and its several details can be modified in various respects, all without departing from the present invention. Accordingly, the drawing and descriptions are to be regarded as illustrative in nature, and not as restrictive.

Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising" "having" "containing" or "involving" and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes.

Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention.

In this disclosure, whenever a composition, an element or a group of elements is preceded with the transitional phrase "comprising", it is understood that we also contemplate the same composition, element or group of elements with transitional phrases "consisting essentially of', "consisting", "selected from the group of consisting of', "including", or "is" preceding the recitation of the composition, element or group of elements and vice versa.

All singular forms of elements, or any other components described herein are understood to include plural forms thereof and vice versa.

Brief Description of the Drawings

Figure 1 is a schematic illustration of an exemplary silo incorporating a mixing unit.

Description of the Preferred Embodiments

Referring to Figure 1, there is shown an exemplary dry mortar silo 1 comprising a mixing unit 2 located at a lower in use end of said silo. The lower in use end of the silo comprises a generally conical section la having an outlet valve such as internal discharge door (not shown) proximate its outlet end lb. The discharge door may comprise a butterfly valve which is opened to allow the material stored in the silo, e.g. dry mortar mixture, to exit the silo and enter the mixing unit 2.

Mixing unit 2 comprises a hopper region 21 and a barrel 22. Inside barrel 22 there is provided a mixing screw (not shown). The mixing screw is powered by an electric motor 23. Mixing unit 2 further comprises a water inlet 24 which allows water to be introduced via a hose from a separate water source (not shown).

In Figure 1, the mixing unit 2 is shown attached to the silo 1. Attachment may be via one or more mounting flanges 25 provided on the mixing unit and/or silo. However, it will be appreciated that a mixing unit 2 need not be directly coupled to the silo, but can be located spaced apart from the silo 1.

Once the discharge door of the silo is opened, the dry mortar mixture falls under gravity from the silo and enters mixer unit 2. Upon activation of the mixer unit, water is also introduced to the mixing unit 2 via inlet 24 and the mixing screw is rotated by the motor 23 so that the dry mortar and water are mixed within barrel 22. The resulting wet mortar mixture is discharged from the discharge end 22a of the barrel 22 in the required amounts and gathered in a tub or bucket (not shown) ready for use at the site.

In accordance with one aspect of the invention, the apparatus for determining the amount of material remaining in a silo comprises a first sensor (not shown) which senses the position of the discharge door of the silo. The first sensor may comprise one or more microswitches or other suitable sensors capable of determining the position of the discharge door of the silo, for example, but not limited to, proximity sensors. The apparatus further comprises a second sensing means which obtains a measurement of the electrical current of the electric motor 23 which rotates the mixing screw of the mixing unit. Outputs from the first and second sensors are communicated to a control unit or module (not shown) located on or proximate the mixing unit 2 or silo 1. The control unit or module is programed to monitor the measured electrical current obtained from the second sensor and to measure the run time of the mixing screw as discussed below.

The measured electrical current of the mixing screw motor, optionally in conjunction with the position of the discharge door of the silo, is indicative of the operational state of the mixing unit. This is because when mixing unit is started (and the discharge door is closed) the load on the motor is low and the measured electrical current will be at a first value. When the mixing unit is operational (the discharge door being in an opened state) and the mixing screw is being rotated to mix dry mortar from the silo with water, the load on the electric motor 23 will be increased and the measured electrical current will be at a second value (e.g. a higher value). When the mixing unit is operational but running a wash-out or 'purge' cycle (whereby the discharge door is closed and only water passes through the rotating mixing screw), the load on the electric motor 23 will be at a third or 'intermediate' value.

For a mixing unit having a particular specification (e.g. screw volume, motor power etc.) the values or range of values for electrical current for each of the possible operational states will be known, or can be calculated, or can be measured empirically. These values are then stored in a memory of the control module or remote device during calibration of the module. In use, by measuring the time (i.e. duration) of each the respective electrical current values, the control module can then record the run time of the mixing device in mixing and purging cycles, as well as the stopped time.

Similarly, for any given period of run time of the screw, the amount of material mixed by the mixing screw (i.e. wet mortar mixture produced) can be calculated based upon the speed of the mixing screw and the screw volume, or can be measured empirically. For example, during calibration of the apparatus, a mixing cycle can be measured over a selected time period, and the weight or volume of wet mortar mixture produced per second (or millisecond) of mixing time can be measured. As the ratio of water to dry mortar will be known, the amount of dry mortar to produce the wet mortar mixture over a period can be calculated. This measurement, which may be a volume or weight measurement, is inputted and stored in the memory of the control module or remote device. Thus, by taking the various measurements for discharge door position, screw load (i.e. motor current) and time spent at the particular current, together with the known values of amount of mortar mixed during a mixing cycle period, the control module can record the cumulative amount of mortar passing from the silo and through the screw as wet mortar mixture, and thereby calculate the remaining volume of dry mortar within the silo.

It will be appreciated that the electrical current of the mixing screw motor may be measured using an ammeter or current transducer.

In many applications, operation the mixing screw motor is controlled by a variable speed drive (VSD) (not shown in the Figure), a VSD being a motor controller that drives an electric motor by varying the frequency and voltage supplied to the electric motor. The VSD is usually connected to the mixing screw motor by a motor cable (not shown). VSDs are also known as variable frequency drives, adjustable speed drives, adjustable frequency drives, AC drive, microdrives, and inverters.

For mixing screw motors that do not employ a VSD for motor control, the speed of rotation of the mixing screw during mixing of the mortar will generally be a fixed speed. Where no VSD is employed, power to the mixing screw motor usually is controlled by a contactor (not shown in the Figure), the contactor being connected to the mixing screw motor by a motor cable (not shown). In this case, the second sensing means operable to measure the electrical current of the mixing screw motor may comprise a current transducer that is connected between the control unit and the contactor.

Where a VSD is employed, a measurement of mixing screw motor current, as well as frequency and voltage, can be obtained from the VSD. Such measurements may for example be taken from the VSD via a communication or "comms" cable. In this way, the second sensing means operable to measure the electrical current of the mixing screw motor may comprise a communication or "comms" cable that is connectible between the control unit and a variable speed drive associated with the mixing screw motor. Alternatively, the second sensing means operable to measure the electrical current of the mixing screw motor may comprise a sensing device such as a current transducer that is connectible between the control unit and the electrical supply cable to the VSD.

As the speed of rotation of a mixing screw is variable where a VSD is employed, and as the speed is directly related to a current's frequency, a measurement of frequency can be used to determine the speed of rotation of the mixing screw.

In this way, in an aspect of the invention there is provided a method of determining the amount of material remaining in a silo, the method comprising the steps of: (i) sensing the position of an outlet valve of the silo, the position of the outlet valve being either opened or closed; (ii) measuring the electrical current of a mixing screw motor of a mixing device associated with the silo; (iii) determining the speed of rotation of the mixing screw; (iv) determining whether the mixing screw is (a) in a mixing cycle, or (b) in a wash-out cycle; (v) when the mixing screw is in a mixing cycle, measuring the duration of the mixing cycle; (vi) calculating the amount of material mixed by mixing screw during the mixing cycle based on the measurements of (iii) and (v) and known values for the amount of material mixed by the mixing screw over a given time period at any given screw speed; (vii) calculating the amount of material remaining in the silo by deducting the amount calculated in (vi) from the known total starting amount of material in the silo, or from a previously calculated amount of material remaining in the silo.

The method may comprise the further step (viii) of saving the value calculated in step (vii) in a memory, for example a memory of the control unit or control module.

The method may further comprise the step (ix) of measuring the ambient temperature.

In one embodiment, the method comprises the further step (x) of transmitting the data obtained from any of steps (i) to (ix) to a remote or cloud based server.

Conveniently, any of the steps (iv) to (vii) may be performed by appropriate software or program running on a remote or cloud based server, or user devices in communication with said remote or cloud based server.

It will be appreciated that apparatus for determining the amount of material remaining in a silo as described herein may be retro-fitted to existing silos and their associated mixing devices. Thus in accordance with a further aspect of the invention there is provided kit of parts, wherein the kit includes a first sensor, a second sensor, and a control unit; wherein the first sensor is configured to sense the position of an outlet valve of a silo, the position of the outlet valve being either opened or closed, wherein the second sensor operable to measure the electrical current of a mixing screw motor of a mixing device associated with the silo; wherein the first and second sensors are in communication with the control unit, the control unit being adapted to monitor the measured electrical current and the run time of the mixing screw, wherein the electrical current is indicative of the operational status of the mixing screw.

It is thought that the present invention and its advantages will be understood from the forgoing description and will be apparent that various changes may be made without departing from the invention, the forms hereinbefore described being merely preferred or exemplary embodiments thereof 15 20 25

Claims

Claims 1. An apparatus for determining the amount of material remaining in a silo that is in communication with a mixing device, the apparatus comprising: a control unit; a first sensing means operable to sense the position of an outlet valve of the silo; and a second sensing means operable to measure the electrical current of a mixing screw motor of a mixing device associated with the silo; wherein the first and second sensing means are in communication with the control unit, and wherein the control unit is configured to monitor the measurements of electrical current to determine the operational status of the mixing screw and is configured to measure the run time of the mixing screw motor at the measured electrical current.
2. An apparatus as claimed in claim 1, wherein the first sensing means comprises one or more microswitches.
3. An apparatus as claimed in claim 1, wherein the first sensing means comprises one or more proximity sensors.
4. An apparatus as claimed in any preceding claim, wherein the second sensing means is operable to obtain the measurement of mixing screw motor current from a contactor associated with the mixing screw motor.
5. An apparatus as claimed in any one of claims 1 to 3, wherein the second sensing means is operable to obtain the measurement of mixing screw motor current from a variable speed drive associated with the mixing screw motor.
6. An apparatus as claimed in any preceding claim, wherein the second sensing means comprises a current transducer.
7. An apparatus as claimed in claim 5 or claim 6, wherein the second sensing means is further operable to obtain measurement of frequency of the mixing screw motor.
8. An apparatus as claimed in claim 7, wherein the second sensing means is a communication or "comms" cable connectible to the control unit and the variable speed drive associated with the mixing screw motor.
9. An apparatus as chimed in any preceding claim, wherein the control unit comprises a memory.
10. An apparatus as claimed in any preceding claim, wherein the control unit is located proximate the silo in use.
11. An apparatus as claimed in any preceding claim, wherein the control unit is located remote from the silo in use, whereby the first and second sensing means are in remote communication with the control module.
12. An apparatus as chimed in any preceding claim, wherein the control unit comprises a user interface.
13. An apparatus as chimed in any preceding claim, wherein the control unit comprises a display.
14. An apparatus as claimed in any preceding claim, wherein the control module comprises location identification means.
15. An apparatus as claimed in any preceding claim, further comprising a temperature sensor.
16. An apparatus as chimed in any preceding claim, wherein the control unit and/or first and second sensing means are adapted to communicate with a remote server, the remote server being accessible via a plurality of user devices to enable a number of remote users to access the data stored on the server to monitor the location and status of the apparatus and to review the data relating to the amount of material remaining in a silo and/or the status of the mixing device associated with said silo.
17. An apparatus as claimed in claim 16, wherein the remote server is a cloud based server.
18. An apparatus as claimed in claim 16 or claim 17, wherein software or a suitable program running on the remote server and/or user devices in communication with the server is adapted to calculate and predict when a silo should be replenished or replaced based on usage rates and material remaining in the silo.
19. An apparatus as claimed in claim 18, wherein the software or suitable program running on the server and/or user devices in communication with the server is adapted to provide a graphical trend of the silo material level over a selectable time period.
20. An apparatus as claimed in claim 18 or claim 19, wherein the software or suitable program running on the server and/or user devices in communication with the server is adapted to interface with third party accounts systems to automatically order and receive material delivered to a silo or silos comprising the apparatus of the invention.
21. An apparatus as claimed in any one of claims 18 to 20, wherein the software or suitable program running on the server and/or user devices in communication with the server is adapted to compile a range of reports relating to mortar production and deliveries over a selectable time period.
22. An apparatus as claimed in any one of claims 18 to 21, wherein the software or suitable program running on the server and/or user devices in communication with the server has means for receiving data inputted by users, said data comprising service interval data for the mixing device, so that users of said device can be alerted when a service interval has been reached or is approaching.
23. An apparatus as claimed in any preceding claim, wherein the apparatus is remotely controllable.
24. A method of determining the amount of material remaining in a silo, the method comprising the steps of: (1) sensing the position of an outlet valve of the silo, the position of the outlet valve being either opened or closed; (ii) measuring the electrical current of a mixing screw motor of a mixing device associated with the silo; (iii) determining the speed of rotation of the mixing screw; (iv) determining whether the mixing screw is (a) in a mixing cycle, or (b) in a wash-out cycle; (v) when the mixing screw is in a mixing cycle, measuring the duration of the mixing cycle; (vi) calculating the amount of material mixed by mixing screw during the mixing cycle based on the measurements of (iii) and (v), and known values for the amount of material mixed by the mixing screw over a given time period at a given screw speed; (vii) calculating the amount of material remaining in the silo by deducting the amount calculated in (vi) from the known total starting amount of material in the silo, or from a previously calculated amount of material remaining in the silo.
25. The method as claimed in claim 24, comprising the further step (viii) of saving the value calculated in step (vii) in a memory.
26. The method as claimed in any one of claims 24 or 25, comprising the further step (ix) of measuring the ambient temperature.
27. The method as claimed in claim 26, comprising the further step (x) of transmitting the data obtained from any of steps (i) to (ix) to a remote or cloud based server in accordance with the second aspect of the invention.
28. The method as claimed in any one of claims 24 to 27, wherein the steps (iii) to (vii) are performed by appropriate software or program running on a remote or cloud based server, or on user devices in communication with said remote or cloud based server.
29. The method as claimed in any one of claims 24 to 28, wherein determination of the speed of the mixing screw in step (iii) is made from a measurement of motor frequency.