FOR several years automated firefighting systems with remote-controlled monitors are used for fire protection of:
- Tank farms
- Petroleum loading terminals
- Aircraft hangars
- Thermal power plants
- Production facilities
- Recycling plants
- Waste incineration plants
To fully utilize the range of potential offered by remote-controlled monitors for firefighting, introducing a programmable (PLC) control system with state of the art communication facilities is mandatory. This allows the connection with automatic fire detection systems and fire alarm control panels for very large and complex facilities.
Features of control systems for automated fixed firefighting systems with monitors
The range of electric control systems for remote-controlled monitors varies from standalone control systems to control a single monitor through to complex systems with multiple monitors where decentralised individual controls are connected with a central control unit via a fibre-optic network. Dependant on the requirement, compact PLC systems or systems consisting of several interconnected assemblies make up the control system. Where high functional safety is required, redundant CPUs(Central Processing Units) can be installed or, alternatively, PLC control systems in accordance with the required safety level (SIL). A daily automatic self-test is one standard feature of today’s control systems. During this process, the functionality of all drives and sensors fitted on the remote-controlled monitors is tested. If a fault is found at one of the components, a corresponding error message is sent to the supervising body. This ensures that possibly occurring failures are reported immediately and can be eliminated before a malfunction during operation happens. This significantly increases the reliability and availability of the automated firefighting system, compared with such systems which are tested for functionality in more or less long and possibly irregular intervals. For easier commissioning, the automated control systems are fitted with an HMI (Human-Machine Interface) option. Thus, during commissioning or a change in program, all threshold values which must not be exceeded by the remote-controlled monitors can be adjusted in the control cabinet without having to make any settings directly at the remote-controlled monitors. In the case of very large systems, this is an invaluable gain of time during commissioning, service and use.
If control systems for remote-controlled monitors are interconnected with fire detection systems (i.e. on the basis of IR [Infrared] cameras), pre-selection of individual zones can be skipped. The monitor will then swivel to an area identified by the fire detection system and will start the extinguishing operation directly at the source of the fire. In case of locally confined initial fires, this results in maximum firefighting success while consuming just a minimum amount of extinguishing agent and affecting only a limited area.
Outlook and conclusion
The technical development in the field of drive engineering, sensor technology and control technology offers some great future potential to detect fires in their initial phase as well as to fight fires in a localized and resource-conserving manner by use of monitors.
Fritz Zimmermann was hired by FireDos as head of the engineering department in 2012. He is in charge of foam-proportioner and fire-monitor design and development.
Previously he worked for Alco for over 28 years in the design and development of fire-monitors and project development for automated extinguishing systems and tank fire-fighting equipment.