Subscribe to our monthly newsletter.

02-12-2021  |  10527 x

From preventive measures such as spark detection to passive measures such as bursting discs to active systems such as explosion suppression. It is crucial that the solutions work together as a whole within the framework of a customised concept and communicate with each other as intelligent systems. The experts from IEP Technologies explain how their latest development, the eSuppressor, ensures intelligent explosion protection throughout.

Intelligent explosion protection begins with prevention
Spark detection is a complex method of preventing fires and explosions. The principle starts directly at the ignition sources - even before a fire or explosion has occurred. Within a millisecond, the spark detector from IEP Technologies detects sparks and automatically sets a process chain in motion: an extinguishing unit extinguishes sparks and glowing particles with a small amount of water. This process is controlled and monitored by the signal router. Meanwhile, the control unit monitors the entire system and, if necessary, triggers acoustic and optical signals to the surroundings. A pressure boosting system ensures that the extinguishing water is free of air and has the correct pressure. A few seconds after the danger has been eliminated, the extinguishing process is finally stopped by the automatic system and the system is immediately ready again to prevent another fire.

Constructive explosion protection with smart sensor technology
As a preventive measure, spark detection forms the link to constructive explosion protection. Here, the SmartDS detection system for early detection of incipient explosions plays a central role: its mode of operation is based on the characteristic temporal course of the pressure rise in connection with spatially limited explosion events. The SmartDS consists of a dynamic pressure sensor with two ceramic cells and an evaluation unit. Dynamic measuring cells in the detector detect pressure changes. As soon as the preset pressure values are exceeded, the detector reacts within milliseconds and triggers an alarm.

The system is the only detector with algorithm-based output and decision logic based on explosion testing, expertise and application experience. This output and decision logic determines the difference between a pressure increase due to an explosion and the normal pressure variations in the process, providing the highest detection reliability and immunity to false alarms. In addition, the integrated FAB4 evaluation unit stores all events and enables all process pressures to be recorded. This helps in the analysis of the cause of explosions as well as in the question of how explosion hazards can be minimised in the future.

Control panels communicate with protective devices

IEP Technologies’ control units are based on a microprocessor and have control and verification functions. They consist of control and battery charging circuits, power supply and a control panel with control and display functions. All signals from the explosion pressure and flame sensors are recorded, checked and evaluated by the control unit. In the event of an incipient explosion, the protective devices are selectively activated. The monitoring and activation lines are constantly checked for interruption, earth fault and short circuit. In addition, an automatic self-test system ensures that all important functions of the control unit are checked electronically. IEP Technologies controllers have both fault relay contacts for process interlock and alarm relay contacts for system trip messages.

eSuppressor as the central link in the communication chain
With the development of the eSuppressor, the circle can be intelligently closed from the suppression container via the control unit, the evaluation unit and the detection. The suppression container works without pyrotechnics such as gas generators. Instead, the innovation is based on an electrical solution controlled by a magnet - an invaluable advantage over conventional triggers that use pyrotechnics. In these systems, the electrical connection can be checked. However, it is not possible to check whether, for example, there is actually gas in the gas generator and it would therefore trigger in an emergency. The scenario is unlikely, but possible. Only ignition would confirm functionality - comparable to a match: it is only certain to actually burn as soon as it is lit. The eSuppressor, however, allows the functionality of the triggering mechanism to be permanently monitored.

In addition, the new suppression vessel ensures intelligent explosion protection in the form of an integrated safety lockout for safe access to the process vessel. It is rebuildable and suitable for all areas in which IEP Technologies already successfully uses explosion suppression - from coal grinding to industries with extremely high hygiene requirements, for example in the production of baby food and milk powder. In both areas, personnel must regularly climb into the containers due to cleaning work.

With the eSuppressor, the electronic, SIL-certified chain between the central assemblies including the suppression container can be efficiently controlled from the control room in the future. The most important advantages of the integrated safety concept: significant improvements in terms of occupational safety and total cost of ownership, as well as the possibility of mechanically safeguarding the pressure vessels by remote control in the future, thus streamlining the workflow. In addition, work safety deficiencies due to human error can be reduced. Due to the continuous networking of the systems, it is possible to realise a seamless explosion protection concept, whose individual components interlock precisely and in fractions of a second. This approach forms the basis for customised, technically and economically optimised overall systems that comprehensively protect people and assets.