NOURISHING BY NATURE

Every day, the customer’s plant – one of the world’s largest dairy companies – supplies dairy products to millions of consumers around the world.
At the customer’s site in the Netherlands, milk is processed into butter products and high-quality milk powder. For this purpose, the plant has five independent spray towers for drying.

THE CHALLENGE

Production-related high temperatures occur during the drying of milk, which can trigger both an explosion and a fire inside the plant. Furthermore, the safety and explosion protection regulations for the equipment of the towers are becoming more and more stringent. The existing fire extinguishing system of the spray towers therefore had to be renewed and adapted to the current safety regulations. In addition, the emergency stop concept and the measuring technology installed in the potentially explosive area were checked and – if necessary – renewed.

THE SPECIAL FEATURES

A customized solution was developed for this work based on the circumstances. On the one hand, components could only be installed or set up where space conditions permitted. Secondly, the conversion was carried out in stages, i.e. after installation of the new fire extinguishing system, the towers were connected to it one after the other during planned production shutdowns. At the same time, the necessary adjustments were made to the respective towers.

THE IMPLEMENTATION

In order to meet the high safety requirements, the first step was to set up a redundant power supply. This was realized by supplying the new fire extinguishing system via a low-voltage transformer during normal operation and by means of an emergency power generator in the event of a power failure.
The genset set up in a container, together with a professional F90 design of the feed line, ensures a power supply even in the event of fire. The controls are additionally equipped with an uninterruptible power supply (UPS) so that there can be no failure of the safety technology at any time.
The fire extinguishing system is fed by three powerful pumps. These are designed for one spray tower each, so that even in the event of a fire in two spray towers, one pump is still available as a reserve. In addition, a pressure-maintaining pump ensures that the riser is constantly filled with water. This enables the part of the plant affected by the fire to be extinguished immediately.
A further component for increasing safety was implemented in that the system automatically undergoes a self-test, including a test run of the fire pumps, during ongoing production operation.
In addition to the fire extinguishing system, emergency stop buttons were retrofitted on all escape routes as part of this project. In the event of a dangerous situation, these lead to an immediate, safe shutdown of the system.
In the course of this shutdown, high temperatures can occur in the spray tower. This challenge was met with the VERTEX cooling system. This cools the supply air temperature down to approx. 110 °C via a total of five nozzles which can be controlled in groups – even if the external power supply fails.