Handling valuable raw materials and products:
 
What’s in the pipeline?
 
Electromagnetic flow metering: a simple and rational method
 
The question as to “What’s in the pipeline?” is very relevant to the issues that process engineers face with regard to the manufacture of beverages or other liquid foodstuffs. Information about how much liquid is actually flowing through a pipe at any given time is very important when it is a question of monitoring and optimising processes during production.
 
Looking at the process technology required to measure flow or volume, there is a number of properties that are extremely important:
·         A high level of reliability
·         Accuracy
·         Perfectly hygienic installation and operation
·         No mechanical wear and no maintenance requirement
·         Low power consumption during operation
·         Simple installation and operation
·         Use and cleaning without any special safety precautions
·         Low capital expenditure
 
In view of this requirement profile, which sums up what the customers want to have, electromagnetic flow metering technology occupies a special position in the food industry. This type of flow meter fulfils all the criteria listed above for metering conductive liquids. As an indication: normal mains water has a conductivity of around 100 μS/cm. Since it is above all aqueous liquids that are processed in the food and beverages industry, the use of electromagnetic meters is to be recommended without reservation.
 
With its newly developed IZMAG™ generation of devices, the manufacturer GEA Diessel has succeeded in reconciling what appear to be contradictory positions: on the one hand the desire of the plant manufacturer for a simple but effective standard device, and on the other hand that of the end user for a flow meter that does not simply measure, but offers a lot of special functions in addition. This new type realises to the full the advantages of the electromagnetic measurement principle in practical application, and fulfils the market requirements outlined above to the optimum degree.
 
IZMAG™
 
 
 
 
 
 
On the safe side
Quality electronics and an efficient design ensure optimum reliability in all customary installation situations.
 
Reliable measurement data
Integrated monitoring processes throughout the measurement chain ensure extremely accurate metering, officially confirmed by the European OIML certificate. There is a special function initiating an inspection routine to generate a quality certificate which documents the reliability of the process.
 
No snags
Thanks to the application of the formula “Process pipe diameter equals measuring pipe diameter”, there are no snags and no corners that might give rise to hygiene problems. The standard aseptic process connection completely fulfils all the precautionary requirements in this respect. Connecting pieces or standard process connections can also be attached to the metering device very flexibly. The device has a pleasing design, and the exclusive use of stainless steel prevents corrosion of the housing and ensures that this hygienic advantage is also expressed optically through the clean and functional appearance.
 
Just install: that’s all!
The great advantage of the principle of electromagnetic measuring devices is that they measure flow without any moving parts. They are thus free of mechanical wear and tear. Only for hygienic reasons is it advisable to change the seals at regular intervals. An internal monitoring routine ensures that, should any defect arise, an alarm message is displayed in plain text and an appropriate signal transmitted to the control unit.
 
Environmental advantages
Process pipe diameter equals measuring pipe diameter – also thanks to this formula there is no fall-off in pressure (it is, after all, “only” a piece of piping that is installed). In consequence of the use of the most modern electrical switching elements, the power requirement is so far reduced that even the use of multiple meters in complex process modules leads to a favourable electrical energy balance. This helps to curb operating costs, and is also good for the environment.
 
Keeping an eye on everything
What is equally important to both the plant manufacturer and the end user is that the device should be simple to operate. The display supplied as standard enables the measured values and thus also the process to be observed at all times during the commissioning phase. Thanks to the design and construction, the installed display can always be rotated in such a way as to be easy to read. Where the device is installed in particularly inaccessible places, a Bluetooth interface is very helpful in allowing the measurement data or the parameter settings of the measuring device to be checked from a remote position. Many alterations of the parameters can of course also be carried out in the same way, and archived to provide for the recommended for optimum tracking and tracing.
 
No ifs or buts
Once the IZMAG™ flow meter has been installed at the desired location, it can be used for years without any further requirements having to be fulfilled. The PFA lining material is resistant to acids and caustic solutions. The device is able to cope easily with partial vacuums, even at higher temperatures, and is also tolerant of flow rates exceeding the rated level, e.g. during CIP. Thanks to the intelligent electronics that provide for automatic switching from one measurement range to another, the measurement process is even able to compensate for excessive flow rates. To allow liquids to be metered even at process temperatures of up to 150° C there are “discrete” versions of the device, in which the electronics are installed separately from the measuring pipe. The device can measure flows in both directions. So in this case you really can say “Install it and forget it!”
 
Keeping your feet on the ground
In cases of capital expenditure, the focus is always not only on the required technology and application, but also on the cost. The universal applicability and simple design of electromagnetic metering devices allow the user to gain initial experience with this technology at a favourable price. As compared to other metering technologies, the cost/benefit ratio of an electromagnetic flow meter such as one of the IZMAG™ type is unbeatable. The range of diameters available will cover all the flow rates customarily occurring in food production. Even where process connections in excess of DN100 are required, the price structure is moderate in comparison with other metering technologies, the costs of which veritably explode in this area.
In order to ensure precise metering, it is sufficient to simply install the device in the process pipe. This applies particularly where the production process excludes the generation of gas. In other cases, it is recommended to provide in the planning for an upstream phase separation between gas and liquid; otherwise, for example in the metering of finished beer, the expulsion of the bound carbon dioxide could lead to inaccurate measurement values. Particularly in plant subject to weights and measures approval, which in the European Union will in future be granted in accordance with the MID directives, all the requirements for error-free metering must be complied with. As with all measuring processes, so also here, it is the case that the greater the experience, the more accurate the measurement: GEA Diessel has been offering solutions for weights and measures approved metering tasks in a wide variety of applications for many years.
 
Special functions and additional equipment that are necessary or advantageous in connection with the metering device add to the range of applications in which the electromagnetic flow meter can be used:
  • Function for regulating the flow rate
  • Function for regulating the proportions in blends and mixtures
  • Simple preselection of values
  • Filling level control with automatic compensation for last runnings
  • Control of short filling processes
  • Selection of eight or more containers of various sizes for the filling control, with filling statistics
  • Integrated temperature measurement
  • Volume standardisation dependent on temperature
  • Recording of data on PC, via bus or wireless link
  • Weights and measures approved remote display as a main or subsidiary meter via bus-transmitted signals or redundant pulse transmission
  • Printing of vouchers with date/time and further details for trading purposes
 
The flexibility in use of earlier GEA Diessel devices has been maintained in the new IZMAG™ generation of electromagnetic flow meters, and will continue to offer the user significant advantages in the future.
 
Summary
Volumetric and flow metering is an extremely important measuring technique in food production. Modern, functional technology using the electromagnetic metering principle, coupled with devices with simplified technology and operation, offer the user a whole range of advantages together with a very good cost/benefit ratio. Thanks to their many years of experience in the field of flow metering technology, the experts at GEA Diessel have succeeded, with the new generation of IZMAG™ devices, in reconciling the requirement for measuring instruments that are simple to use on the one hand, and complex system components on the other.
 
 
Author:
Hermann Hartmann, Dipl. Phys. GEA Diessel GmbH,
Head of Department: Metering and Data Technology