Bilfinger GreyLogix foodtec Makes Spray-Drying Safe


Many products in our daily lives are produced by means of spray drying. These reach from milk powder over instant coffee up to vaccines. The manufacturing process is very complex, though: simply put, concentrated products are pushed through a sprayer or a jet and dried with hot air intake. The resulting product is a dried powder with a long shelf life. However, the high temperatures can cause fires or even explosions in the plant during the drying process. The relatively high age of many plants increases this risk even more.

Against this background, Bilfinger sees great business opportunities in this field and has now founded its own department with 20 employees within the subsidiary GreyLogix foodtec. This department deals with all safety-related aspects concerning spray drying and at the same time promotes technological developments. „Safety and safety technology are playing an increasingly important role“, says Matthias Buch, general manager at Bilfinger GreyLogix foodtec. „We have recognized this and have developed a comprehensive package with many simple and ingenious solutions. In addition, we will invest further in new developments.“

For a safety-related upgrade the age of a plant is not the only decisive factor. The legal safety requirements also have steadily increased in the past years. Hence, modernization is required. Bilfinger offers a comprehensive bundle for the safety of the spray drying plant – from the analysis of the current situation over the concept for improving the safety coordinated with the authorities up to the installation of the components. Furthermore, the company also provides comprehensive services like maintenance, if desired.

The safety team at Bilfinger GreyLogix foodtec consists of experts in plant engineering as well as engineers from the process technology. The package resulting from this wealth of experience comprises different modules, which significantly increase the safety during production. The great advantage: The individual components are compatible with each other as well as with many third-party systems. The companies, which are using the innovative Bilfinger safety solutions in milk processing, include Uelzena, Rücker, and Deutsches Milchkontor.

Employees of the Safety Technology team of Bilfinger GreyLogix foodtec GmbH

An innovative module of the portfolio is the carbon monoxide (CO) detection system „Detex“ for the spray drying, which has ensured a safe production of milk powder for three years by now. It monitors the spray dryers for glowing embers, which, in the worst case, can lead to an explosion in the plant. Detex is fitted with a two-channel analysis module. The benefit: The absolute measurement values of both the air intake and the exhaust air are available at any time. Thus, it is possible to clearly recognize interferences outside the process and minimize unnecessary production stops.

In case a plant needs to be shut down immediately and cooled down to a non-critical temperature range, the cooling system „Vertex“ comes into play. Vertex prevents superheating of the air intake flowing to the drying chamber independently from the mains supply voltage and cools the air down in a controlled manner. The basic principle is based on evaporative cooling, which is achieved by a fine spray of water into the air intake duct of the drying chamber. The energy removed from the hot air through this process reduces the air’s temperature to a non-critical value – without damaging the powder present in the drying.

Despite all precautions, the chance of fire or even an explosion can never be fully ruled out. In order to ensure greatest possible protection even in such cases, Bilfinger has explosion protection systems to offer, as well as tailor-made fire extinguishing systems.

Even when working in the plant itself, the safety can be increased in a highly effective way. Bilfinger offers an innovative key transfer system for maintenance holes. This ensures that the closed holes remain locked until it is safe to open them. In the same manner, it prevents dangerous operating conditions to occur when the holes are open. For this, a locking mechanism is installed at each maintenance hole, which can be opened only with a key specifically designed for this mechanism. When the plant is in operation, the keys are in a key board, which has an electronically monitored slot for each key. If a key is removed, the plant will be locked against unsafe operating conditions and will be shut down in a controlled manner.

Internal training of the safety technology team of Bilfinger GreyLogix foodtec GmbH