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.
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.
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.
Lösungen für Sprühtürme
detex – CO-Detektion
vertex – Kühlsystem
fire extinguishing system for spray towers
- 3 Fire pumps
- 1 pressure maintenance pump (3 m³/h against 13 bar)
- VERTEX cooling system for each spray tower
- 1 Diesel emergency generator 220 kW according to VDE 0100 part 718
- Measuring instruments in Ex version: Endress & Hauser
- Control system: Siemens Step7 with WinCC
- Data points: ca. 800 I/Os
- Data points: Ja
- Stations: 6 Stück S7- 315-2DP failsafe
Scope of delivery
- Delivery and assembly of three fire pumps and one pressure maintenance pump
- Installation of the new fire extinguishing system incl. installation of the spray nozzles
- Fünf VERTEX Kühlsysteme
- Establishment of a new emergency stop concept incl. adjustments to the control cabinet wiring
- Fail-safe program for controlling the erasing process
- Control cabinet conversion
- 10 days 24h production support
- 24/7 On-call service
- annual maintenance of the fire extinguishing system