A study was performed at BASF Antwerp regarding two tank pits with four large tanks and seven smaller tanks.
These tank storage areas were already equipped with fixed fire extinguishing systems but required a redesign and renewal. The renewal of the systems had to be carried out in a live production environment.
The outcome of the initial risk assessment was the following:
- The smallest tanks can be cooled and/or extinguished using mobile equipment.
- The large storage tanks (ø 50m) need a fixed cooling and foam suppression system.
- The bund areas need a fixed foam suppression system.
The challenge was to install all new piping and keep the functionality of the existing fire extinguishing system for as long as possible. This has been successfully completed and the system now includes additional connections to feed mobile equipment with large capacity.
The available firewater capacity is a maximum 100.000 litres per minute using brackish water from the port, so an inexhaustible source.
The foam concentrate is stored in two 150 m² storage tanks connected to foam pumps. A separate piping network for the foam concentrate has been installed so that it is available on the entire site.
For this system the use of the electronic foam mixer FoamTronic, was chosen. The system demand for the foam suppression systems varies between 5000 lpm and 45000 lpm. For this area a 3 percent AFFF foam concentrate was used.
FoamTronic is an electronic foam mixing system which very accurately mixes foam concentrate and water based on the actual firewater demand of the system. This is achieved by continuous monitoring of the firewater and foam concentrate flows using electromagnetic flowmeters and real-time adjustment of the concentrate control valve.
The advantage of the FoamTronic system is that there is no pressure loss in the water supply towards the extinguishing systems. There is only an electromagnetic flow meter installed in the water pipe of the manifold. As a result, the new piping diameters could be reduced.
Classic foam proportioners require to be tested mixing water and foam concentrate to ensure the proper mixing ratio.
Testing of the mixing ratio for mechanical proportioners would create enormous amounts of wastewater, use large amounts of foam concentrate and, therefore, result in serious financial loss.
FoamTronic allows system performance to be regularly tested without mixing foam and water, thus avoiding environmental concerns and depletion of costly foam stocks. By using a FoamTronic foam proportioner the cost for annual system testing and the impact on the environment has been reduced significantly.
In cooperation with their sister company Knowsley SK, the FoamTronic was delivered as a skid, ready to put in place at the project.
The new manifold is located near the tank pit, behind a fire-resistant concrete housing.
After placing and testing the new manifold, the areas where the pipes were to be renewed are divided into smaller zones. The zones were temporarily protected during the work with large mobile monitors. These monitors were connected to the new manifold.
All systems have been tested thoroughly to ensure proper operation. One part was testing the FoamTronic foam proportioner. The tests were carried out without using foam concentrate. The foam concentrate was collected in a cleaned tanker for re-use.
By implementing the FoamTronic system, total project costs were significantly reduced. This has been achieved by allowing the reduction of the pipe diameters within the system. In addition, during commissioning tests, a foam concentrate was not used. In the future, the savings will be realised each year by the low costs of the periodic tests and maintenance activities.
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