Lightly carbonated with small bubbles and absolutely pure – that’s how a fresh draft should be. Perfectly timed to coincide with the 500-year anniversary of the German purity laws, a team of experts at the Steinbeis Innovation Center for System Solutions in Measuring and Automation Technology in Mannheim have achieved a breakthrough in a rather tricky area: keeping beverage tap units clean for utmost safety and quality. The team worked together with Flexxibl GmbH in Braunschweig, Franz Mathes GmbH in Manching, and THONHAUSER GmbH in Austria to achieve this new development. So now an automated and certified cleaning option will help keep a centuries- old quality standard in place for continued drinking indulgence.
Lightly carbonated with small bubbles and absolutely pure – that’s how a fresh draft should be. Perfectly timed to coincide with the 500-year anniversary of the German purity laws, a team of experts at the Steinbeis Innovation Center for System Solutions in Measuring and Automation Technology in Mannheim have achieved a breakthrough in a rather tricky area: keeping beverage tap units clean for utmost safety and quality. The team worked together with Flexxibl GmbH in Braunschweig, Franz Mathes GmbH in Manching, and THONHAUSER GmbH in Austria to achieve this new development. So now an automated and certified cleaning option will help keep a centuries- old quality standard in place for continued drinking indulgence. The idea of developing a measurement device to determine the cleanliness of a beverage tap first came about in 2013 during a visit to Vienna. At the time, the Steinbeis Innovation Center was working with other partners on a research project that involved developing a cleaning agent for the food industry. Once back in Germany, the Steinbeis team developed an initial concept for a hygiene sensor system. This involves colorimetric analysis to determine and display the degree of impurity detected (based on a traffic light system). The HSS16 conductivity sensor developed by the Steinbeis experts is used to check whether there are any residues in the system. The beverage tap unit only reverts back to full use once the system gives a green light, indicating there are no more cleansing suds in the unit. Thanks to this double confirmation (colorimetric analysis paired with conductivity), it is possible to retain quality and actively prevent accidents with cleaning agents.
The first cleaning step involves flushing the tap unit with water and then filling it with a 3% solution consisting of DesanaTM disinfectant mixed with water. This solution is left to take effect over a given period of time. When the unit is then subsequently cleaned, the color of the cleaning solution is checked. If the solution came into contact with organic residues, the color will change making it possible to check if the cleaning process was actually successful. If the color changes, the sensor issues a command to repeat the cleaning sequence starting with step 1. If the color remains the same, the unit is flushed with water in three steps. During the third rinse, the HSS16 sensor measures the conductivity. If any residues of Desana or living/ dead organic matter are detected, the unit is rinsed once more with water. As soon as the HSS16 sensor stops finding residues of the cleaning agent, the cleaning process stops automatically and the beverage tap unit is released for use.
The HSS16 is equipped with two connectors, each capable of attaching a 9mm hose. These allow the cleaning fluid and water to run in and out of the device and they are connected to a casing that’s sectioned off into two measurement chambers. The first chamber is fitted with two display windows to track color changes. The conductivity sensor is built into the second chamber. An 8-pin connector has been mounted on the casing to allow the HSS sensor to communicate with the tap unit and to deliver power to the system. There is also a USB interface to allow connection to a PC. An LED was also installed to give the user visual feedback on the current status of the sensors. Measurements can be started manually using a switch.
The measuring system used for color detection consists of a white LED that shines into the measurement chamber through a viewing pane. In addition to this source of light, an RGB sensor has also been installed. Its job is to determine the spectral characteristics of the light source. This is necessary to compensate for age-related changes in the LED and how it reacts to rays of light. An additional RGB sensor is mounted outside of the measurement chamber at an angle of 90°. It acts as a receptor (through a viewing pane) for light modulated by the fluids in the measurement chamber. The data of both RGB sensors is standardized and then converted into HSV color space data. This data is then converted into the HSL color space. There are two advantages of this compared to the RGB color space: it provides a scale of color values that makes it possible to determine the H value of scattered colors. Also, saturation can be used to determine the smallest amount of fluids containing color.
A sensor made by a company called JUMO is used to measure conductivity and thus detect whether the system is free of cleaning agents. An evaluation is carried out via a measuring circuit and the conductivity is calculated using Ohm’s law. The built-in temperature gauge is used to keep conductivity constant despite temperature fluctuations. Once a cleaning process is initiated, the conductivity of the water is measured in a predefined cycle to determine a threshold value. If the measured temperature falls short of this during flushing, the system is deemed free of cleaning agents.
The innovative beverage tap unit developed by the Steinbeis experts was first presented at SME Day in Berlin in 2015. Further presentations of the sensor system followed at the BRAU trade show in Nuremberg and the 27th expert round table for beverage tap units in Weihenstephan. Many experts expressed interest in the sensor and the results produced by the system. That’s because to date there is no automated and validated cleaning method for beverage tap units. The plan is to start using the HSS16 beverage tap unit sensor this year. As a result of this innovative breakthrough in beverage tap unit cleaning and beverage tap solutions overall, the two project partners (Flexxibl GmbH and the Steinbeis Innovation Center for System Solutions in Measuring and Automation Technology) have successfully licensed out the results of their research to a measurement device manufacturer. Franz Mathes GmbH will be exclusively responsible for selling and marketing the HSS16 sensor. Redl GmbH (from Hollabrunn, Austria) is set to become the first company to come on board from the beverage tap industry. It will use the sensor in an automated tap cleaning system called Cleaning Mate. Before the product is rolled out on the market in the summer of 2016, numerous tests will be carried out on the two prototype units at the Technical University of Munich (Weihenstephan campus) to ensure the system has been carefully inspected.