Zwettler’s new energy-saving installations help enable the brewery to operate in an even more environmentally sound way. By Andreas Biniasch, technical writer, ifm electronic.

Zwettler’s private brewery has invested approximately €15 million (US $18.5 million) to expand and modernise their facility in the town of the same name in Lower Austria. The move positions them uniquely in the European market for highly flexible and automatic brewing of high-quality beers.

Complex valve manifold: sensors ensure transparency (First image)

The new energy-saving installations help reduce the need for resources, enabling the brewery to operate in an even more environmentally sound way. Many sensors ensure process feedback and diagnostic data for the brewing equipment up to the control level.

Detailed engineering was implemented by M&L Consulting from St. Gallen, as well as Corosys, a company from Hofheim, with an individual construction and complete automation equipment. As leading Original Equipment Manufacturers (OEMs) for the brewery and beverage industry, M&L Consulting and Corosys rely on a wide product portfolio of sensors and control systems from ifm to guarantee maximum process reliability and machine uptime. This is an important factor to comply with the required standards and directives. In the food industry, in particular, high temperature, cleaning resistance and protection rating IP 68 / 69K are required.

Sensors In The Cold Area

The process chain in the brewery is roughly divided into three areas: the brewhouse, cold area and filling. From the point of view of process sensors, the cold area is the most interesting part. Countless pressure, flow and temperature sensors are installed on the tanks and pipes, and all valves are equipped with inductive sensors for position detection.

Temperatures, pressures or levels:
different sensors monitor the process.

The examples below show how Corosys has utilised the application in the Zwettler brewery with ifm sensors.

Electronic Manometer In The Diatomaceous Earth Filter

Following the fermentation and storage process, the unfiltered beer reaches the diatomaceous earth filter. Here, the yeast cells and sediment are filtered out. The condition of the filter is monitored via different pressure measurements. Then, the fully electronic PG2894 contact manometer is used for this process. It combines the advantages of an electronic pressure sensor and a highly visible manometer display. The pressure pick-up has a hygienic flush design, optionally with conical G1 thread or Aseptoflex Vario process connection. This process connection also allows hygienic flush installation using the available adapters.

In combination with the ecolink socket of the EVT series in M12 design, protection rating IP 68 / IP 69K ensures the highest ingress resistance in the wet area. Thanks to its temperature resistance, the fully electronic contact manometer is also perfectly suited for CIP (cleaning in place) / SIP (sterilisation in place) processes.

The large pointer display, the integrated digital process value display, and the LED bar graph for switch point and trend display provide the operator with a user-friendly readout. With its high total error accuracy of 0.2 percent, the device can also be used for sensitive processes.

2-in-1:
the fully electronic PG contact manometer combines a
pressure sensor and manometer display in one unit.

Temperature Monitoring During The Production Of Mixed Beverages

In addition to the pure beer, Zwettler also produces mixed beverages such as the popular “Radler”—beer with lemonade. At the mixing station, additives from various tanks are mixed. To ensure an optimum process, defined medium temperatures are required.

At the tanks, temperature transmitters of type TA34 transmit the temperature value to the plant controller via an analogue signal (4…20 mA). The hygienic G 1/2 process connection and the high-grade stainless steel (316L/1.4404) housing material mean that direct contact with the medium is no problem at all. The high-precision Pt1000 measuring elements of accuracy provide class A precise measurement results.

Temperature probes of type TM4501 with hygienic G 1/2 process connection are integrated in the pipes. The sensor signal is evaluated and transmitted by the separate TP3231 temperature plug. It is very compact and has two standardised M12 connections for both the connection of the sensor and the output. This reduces the installation complexity—as compared to a common head / DIN rail transmitter—to a minimum.

Small, compact, cost-effective:
the TP temperature plug converts the sensor signal
into a standardised analogue signal (4…20 mA).

Self-Monitoring Temperature Sensor In Flash Pasteuriser

To kill microorganisms and to preserve the beer, it is heated to a defined temperature by means of flash pasteurisation. High precision is of the highest priority. A special sensor is used for this purpose: the ifm TAD991 temperature transmitter uses two different sensor elements which monitor each other in the process. This self-monitoring system ensures that any drifting (deterioration of the sensor’s accuracy) is detected at once and is reliably diagnosed.

Standard temperature sensors have a resistance measuring element which often complies with the accuracy class A to DIN EN 60751 in the food or pharmaceutical industry. A resistance measuring element (Pt1000) is integrated into the TAD temperature sensor. This resistance element is specially measured and preselected by the manufacturer. Its accuracy is, therefore, higher by about factor 4 than class A, which is normally used. To have a signal to compare, the probe of the TAD has an NTC measuring element with long-term stability, which is matched with the characteristics of the Pt element in the production process of the sensor. By this, it is possible to understand the matching of two components or characteristics.

Therefore, in normal operation, the TAD temperature sensor works with two different measuring elements. As a result of this, the process can be finished safely with the second measuring element (backup function) if one element fails.

Maximum process reliability: the self-monitoring TAD
temperature transmitter for especially sensitive processes

Level Monitoring On Tanks

Tanks are used in many places in the brewery: for example, in the bright beer cellar as a buffer between filtration and filling, in water purification, or in the central CIP installation. The exact level of these tanks is needed for plant control. Furthermore, the permissible minimum and maximum levels should be detected and signalled.

Pressure sensors of the PI28 series are installed at the bottom of the tank for hydrostatic level measurement. The exact tank level can be derived from the measured hydrostatic pressure.

The housing of these sensors is completely made of high-grade stainless steel (316L/1.4404). Together with the high protection rating IP 68 / IP 69K and the process-oriented design, this series is particularly suited for hygienic applications.

The new G1 process connection, Aseptoflex Vario, made of high-grade stainless steel (316L/1.4435), provides four reliable sealing options. The metal-to-metal, as well as the new PEEK seals, are maintenance-free and therefore, ensure cost savings during their lifetime. The latter is also distinguished by high resistance to chemicals and temperature.

Elastomer O-rings are another hygienic sealing option (EPDM / FKM). Different process adapters (such as clamp, DIN11851 pipe fittings, and so on) are available as accessories, and are also made of high-grade stainless steel (316L/1.4435).

Depending on the sensor type, their pressure range is between 100 mbar and 25 bar. Other features include the high-purity ceramic measuring cell, as well as easy handling—via the integrated pushbuttons—and the LED display.

Electrically, the sensor can be connected as a 2, 3 or 4-wire unit. This makes it easier to exchange units in existing installations. Furthermore, the sensors of the PI28 series are distinguished by a high overall accuracy (0.2 percent) and electronic temperature compensation. Due to their high temperature resistance, they are also ideally suited for CIP and SIP processes.

The second sensor system on the tank is the LMT point level sensor, which reliably monitors the maximum and minimum levels. As opposed to other solutions such as mechanical tuning fork probes, it does not need any mechanical components and, therefore, operates without wear.

Typical tank monitoring: LMT point level sensor hydrostatically
measuring PI pressure sensor on the tank bottom.

Applications In Pipes

The point level sensors of the LMT series are also used in pipes. They detect if the pipes are full or empty, and are, therefore, used as run-dry protection for pumps. Its compact sensor tip allows the integration of the LMT even in small DN25 pipes.

To monitor the conveying pressure in pipes, the above-described PI28 pressure sensor is used. It transmits the measured value as an analogue signal to the controller.

Perfect pump protection: the LMT point level sensor (top) determines if the pipe
is full or empty. The PI pressure sensor (bottom)
monitors the conveying pressure.

Inductive Sensors Monitor Valve Manifold

To guide the medium, valves on manifolds of different sizes are used in different places in the brewery. Electromechanical rising stem valves ensure an open or closed pipe, allowing the controlled distribution of the media.

Inductive sensors are used for position detection, since they detect if the valve is open or closed by means of the position of the valve stem. The type of IFT203 sensors used feature high-quality housing material (high-grade stainless steel, PEEK) and the high protection rating IP 68 / IP 69K, so that they withstand regular high-pressure cleaning processes without being damaged.

Position feedback: the IFT203 inductive sensor monitors the
valve stem and signals to the controller if the valve is open.

Manway And Cover Monitoring

Another application for inductive sensors is position monitoring of manways or covers—on tanks, for example. The sensors of type IIT212 provide sufficient sensing range (15 mm) to signal the status, “cover open” or “cover closed”, to the controller, even in the event of mechanical tolerance.

Cover closed? An inductive sensor monitors the tank cover.

Looking To The Future

Thanks to many years of experience in the field, ifm offers a comprehensive product portfolio to reliably automate the brewing process and ensure continuously high beer quality. Due to similar requirements, application solutions can be transferred to other areas in the food and beverage industries to make them fit for use.

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