In the town of Vicenza in northern Italy, two lovers of perfection came together. One was trying to find the perfect aroma, the other the perfect position for a sensor in the silo. Coffee lovers around the world now benefit from this obsession when they get the result: a great-tasting blend of coffee beans.

Whether green coffee, roasted coffee beans or ground coffee – the quality standard at Julius Meinl is high. The multinational corporation is regarded as the worldwide ambassador of Viennese coffeehouse culture. Before coffee lovers can relax and enjoy their coffee, a long production process takes place. Achieving mastery in this process demands decades of experience, a mark that the company undeniably surpasses with over 150 years of expertise.

The head office of Julius- Meinl is in Grassa, Vienna, with a production facility in Vicenza in northern Italy. Italy is where the company built its state-of-the-art roasting plant in 2005.

Decades of experience flow into both locations because, for a perfect bean, you need not only sophisticated methods but above all, the skills of a master roaster, who in turn supervises every step of the coffee production.

This encompasses the entire transformation cycle: from receiving and storing the green coffee to cleaning and roasting to packaging the finished product for the end consumer.

When is the right time to change the mix?

Previously, the production team was dissatisfied with the level of measurement capabilities of coffee beans in the silos at the Italian site. These silos had individual rotating paddles and capacitive-level sensors for point-level detection.

The inventory monitoring system used did in turn not fit the requirements of the company as it was based on the calculation of the difference between the input of the raw material and the output of the final product.

A visual inspection had to be done manually as the volume of the coffee beans in the silos was estimated based on the weight of the incoming product, so the actual material inventory in the silos was always unknown.

This made planning sales and production campaigns much more difficult because the exact amount of coffee in storage in the silos was never really known. The silos used were without any form of reliable stock control, and certainly a long way off from any continuous system of level monitoring.

This resulted in considerable inaccuracies and unnecessary stock costs.

Continuous monitoring of silo contents

Julius Meinl was keen to address the challenges they faced in the silos, and to remedy this, VEGA-level sensors were installed to support the existing sensors in the silos and provide reliable readings for more accurate planning.

When it came to measuring the level of coffee beans, there were several challenges in the Vicenza storage silos.

First, there are various internal structures in the hoppers, which are between 3 to 4 meters high, and the design of the silos is anything but ideal for level measurement – they are square and have a conical bottom.

Lastly, there is always suspended dust and buildup in the storage silos holding the roasted coffee. Any sensor installed would therefore get dirty all the time. This area is also classified as ATEX Zone 20.

That explains why several different installation points for a level sensor were first examined, to find the optimal measuring location.

Julius Meinl decided in favour of a non-contact VEGAPULS radar level transmitter, which features extremely tight focusing and a wide dynamic range. For this project, a total of 23 VEGAPULS sensors were installed in the silos.

The transmission frequency of 80 Ghz generates a very precise measuring beam – with its 80 mm antenna, the beam angle is only 3°. This allows the sensors to be used in silos with internal structures because the beam simply passes by such obstacles.

With this groundbreaking technology, the radar sensor receives only the correct reflection back from the product surface. This results in more accurate and reliable stock measurement than was previously thought was possible.

The 80-GHz radar sensor impressed the plant technicians with its extreme accuracy, especially during the silo-filling process. Because of its adjustable flange seal, the sensor antenna can be easily aligned to the surface of the bulk solid. This allows the measurement to be optimised even further.

To achieve this, two wedge-shaped seals can be rotated around each other to achieve any angle between 0 … 8°, without needing any additional tools.

The VEGAPULS level measuring instrument makes it possible to monitor the level providing real-time data on the actual quantities in the silos. This improved the operational processes.

Always knowing exactly how much coffee is present in the silos and getting a confirmation of complete silo emptying (stock below the specified minimum level) avoids any possible cross-contamination between the product lines and blends.

Reliable silo emptying

In addition to the continuous level devices in the silos, multiple VEGAPOINT 31-point level sensors were installed in each of the batch transit bins to detect the empty level as specified by the client.

Once the mixture preparation is finished, the system will notify the production facility that there is no product left in the bunkers. Any anomaly, whether due to sensor failure or inaccuracies, can lead to measurement errors with significant effects. The capacitive sensors used for this function in the past required frequent re-calibration due to product moisture fluctuations.

In contrast to this, the VEGAPOINT 31-level switch is simple and maintenance-free. It can be deployed without any adjustment or calibration.

The VEGAPOINT sensors were installed on the continuous flow hoppers. These sensors alert the central control system whether raw materials are present in the silos and production batches are controlled using the measured values supplied by the level sensors.

The installed VEGAPOINT 31-level sensors have long since proven their robustness in practice and have been working flawlessly since their installation, always detecting an empty silo with high reliability.

Reliable support throughout the commissioning process

Julius Meinl was impressed not only by the sensors but also by the service of VEGA’s personnel.  Project managers at Julius Meinl commented on VEGA’s patient search for the best installation position for each of the radar-level sensors as the incorrect positioning could cause problems.

The VEGA technicians provided unwavering support to the coffee specialists during the installation and setup process, ensuring a smooth experience without any disruptions caused by internal silo structures. The technicians expertly executed a meticulous linearization process using volumetric data from the containers.

As a result, the measurements have become highly precise, enabling dependable monitoring of the filling and storage processes.

The installation and commissioning of the VEGAPOINT sensors were carried out by the Julius Meinl employees. No difficulties were experienced during installation and commissioning, thanks to help from the VEGA Tools app and the Bluetooth connection used to communicate with the VEGA products used.

Bluetooth allows the plant maintenance team to commission and diagnose the sensors wirelessly, with the use of a smartphone or tablet. Adjustments to the VEGA instrumentation can be carried out from a distance of up to 25 meters.

With the VEGA Tools app, the user can access and display all important data, such as measured values, event memory, sensor status, echo curves and Bluetooth range information. By using a few simple calibration steps with the smartphone, the VEGAPOINT level switch can detect the complete emptying of the flow hoppers – even with buildup on the sensor.

The technician can in real-time view the status of the instruments and the switching conditions, for example, whether the hopper is empty/ full or whether there is a fault.

This crucial information is immediately visible from any direction, thanks to the 360° status display on VEGAPOINT. This additional status display makes the VEGAPOINT sensors a valuable aid, especially in areas that are difficult to access.

 

In addition to providing dependable and top-notch sensors, VEGA won high praise from Julius Meinl for their considerate approach to business, strong partnership, and technical expertise. What truly left a lasting impact was VEGA’s meticulous attention to detail and unwavering determination in finding the ideal installation positions on the silos.

This shared commitment to perfection became the common ground between VEGA and the coffee specialists at Julius Meinl, fostering a deep appreciation for their partnership and mutual pursuit of excellence.

 

Miguel Petersen

Vega Controls SA (Pty) Ltd
Tel. +27 11 795 3249
miguel.petersen@vega.com
www.vega.com

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