Precise Level Measurement for High-Quality Chocolate Production

“Square. Practical. Good.” Everyone knows RITTER SPORT’s chocolate bars are just that. Their top priority in production is to maintain quality, safety and efficiency. For instance, the process begins with the storage of raw materials in the silo building with six stainless steel silos. Of these, three are used for milk powder and three for lactose. Next, the ingredients are distributed into the day silos prior to being weighed. Finally, they are blended together with the other components in the mixing unit.

“Square. Practical. Good.” Everyone knows the chocolate bars from RITTER SPORT. Image Credit: VEGA

In the silos, the level of milk powder and lactose is measured and recorded. Image Credit: VEGA

The silos’ environment is unfortunately not exactly a friendly one for level gauges. The internal temperatures are often very high. Naturally, this creates additional demands on the sensors. For example, overpressure can build up when the silos are being filled, making the filters clogged. Here, VEGABAR 82 pressure transmitters are deployed and VEGAVIB 63 sensors are used for overfill protection.

Together, both instruments help protect against the build-up of excessive pressure and vessel overfilling. In addition, there also needs to be provisions for special dust explosion protection. During the filling of the silos via compressed air, milk powder or lactose is whirled up. These fine materials then settle everywhere, including the measuring instruments. Thus, exact measurement of the level is absolutely necessary irrespective of such conditions.

Up until now, a sensor based on guided microwave technology had been used for level measurement. Moreover, to protect against silo overfilling i.e. for point level detection, RITTER SPORT had been using a capacitive method. Finally, new silos were eventually installed which meant that RITTER SPORT now needed a state-of-the-art solution.

Reliable Measured Values

This is when VEGA recommended the radar level sensor for bulk solids, VEGAPULS 69, which was launched on the market in 2016. As a result, the Waldenbuch chocolate manufacturer was amazed by the hugely more accurate measurement results and the distinct echo curves provided by VEGAPULS 69. Operating at a very high frequency of 80 GHz, this non-contact radar sensor’s DN 80 antenna generates a beam angle of only 3°, as opposed to the normal 10°. Consequently, this enables tighter focusing and media with poor reflective properties can be detected with much more reliability.

What’s more, the instrument is completely unaffected by build-up, dust or internal vessel installations. The VEGAPULS 69 detects poorly reflecting bulk solids reliably even at distances of up to 120 m, thanks to its particularly good focusing and large dynamic range.

Despite the fact that the 11 meter-high silos at RITTER SPORT are not extremely high, the nominal range of the sensor indicates the tremendous measurement performance reserves. Further, the level measuring process is also extremely rapid, with a cycle time of less than one second and an accuracy of ±5 mm.

The silos in which VEGAPULS 69 is used are about 11 m high. Image Credit: VEGA

An additional feature that convinced RITTER SPORT was the swivel mount with rinsing air connection, wherein the selected flange version is equipped with a swiveling holder of high-quality stainless steel allowing the sensor and antenna to be optimally aligned in a range of ±10°. The company was also benefited by the VEGA app, which can be used to adjust the inclination angle for optimum installation of the measuring instrument. By entering only the silo data, the app automatically calculates the correct tilt angle.

Once this is done, the smartphone or tablet is simply placed on the instrument. The display enables the quick and easy alignment of the radar sensor by means of the swiveling holder.

The antenna is then cleared of any deposits by the supplied rinsing connection. This is even though VEGAPULS 69 generally delivers reliable measured values even when covered with heavy dust deposits, due to its low sensitivity to build-up.

One of the features especially appreciated by RITTER SPORT was the option of parameterizing the sensor with the display and adjustment module PLICSCOM via Bluetooth. Used for measured value indication, adjustment and diagnosis directly on the sensor, PLICSCOM is a standard feature on all VEGA measuring instruments. With the Bluetooth function, it is now possible to adjust the sensor wirelessly from a distance of approx. 25 m. What’s more, the adjustment functions of the radar sensor can be easily accessed using a smartphone or tablet.

The Bluetooth function now makes it possible to adjust the sensor wirelessly from a distance of approx. 25 m. Image Credit: VEGA

This information has been sourced, reviewed and adapted from materials provided by VEGA.

For more information on this source, please visit VEGA.