Smoke extraction for buildings in the event of fire
In the event of fires, it always turns out that the real danger is smoke. Imtech develops individual solutions according to the protection targets, with the priority on ensuring that individuals can escape and facilitating the rescue of those who can't.
Smoke caused by fires is sometimes highly toxic and can lead to long-term diseases or even death if inhaled. There is thus only one answer if humans and buildings are to be properly protected: the smoke must be removed from the risk zone with the aid of technical systems.
By producing low-smoke layers it is possible to guarantee a clear view of the escape routes and prevent people coming into closer contact with smoke from fires. As the flow processes in buildings are subject to the laws of turbulent flow, the Imtech engineers work out dispersal mechanisms either by means of CFD simulations or by tests on models in the laboratory. We often develop special solutions to maintain a smoke-free zone over the necessary timescales.
Largest artificial whirlwind in the world
One example of a special solution of this kind is the smoke dispersal concept developed by Imtech for the Mercedes-Benz Museum in Stuttgart. To prevent people being injured or valuable exhibits being contaminated in the event of a fire, a solution which might seem somewhat unusual at first glance was developed in the Imtech laboratory to enable the museum to operate as an open-plan structure.
In the event of a fire, the smoke is dispersed from the exhibition areas through the large openings and out into the atrium. An artificial whirlwind extending over the entire height of the atrium (approx. 40 m) was developed to prevent the smoke penetrating other floors of the exhibition. The smoke is drawn in due to the considerable drop in pressure from the outer edges to the eye of the whirlwind, then expelled to the open air via an axial fan mounted in the ceiling area.
We were able to implement this unusual technical innovation purely by means of the units designed to ventilate all the exhibition floors, thus making it possible to execute this unusual design cost-effectively.
INFOBOX
Effective protection by ROM-Drall® modules
The development of Imtech's patented ROM-Drall® is one of the technical milestones in ventilation engineering. This process uses the flow principle behind naturally-occurring whirlwinds in a controlled and protected technical environment, and forms the basis for numerous Imtech process and component developments. ROM-Drall® modules are exceptionally suited to direct smoke capture and keeping escape routes in large atria, lift shafts, tunnels or walkways between buildings smoke-free in the event of a fire, thus guaranteeing secure survival zones. Particularly tricky air purification problems in heavy engineering, the automotive industry, foundries and working environments polluted with dust or solvents can be resolved using such capture devices.
Unlike traditional smoke extraction techniques based on smoke and heat extraction systems ROM-Drall systems extract fire smoke and fumes directly from the area around the source of the fire and thus offer significantly higher safety potential in the case of smoke extraction flows which are usually fairly minimal.
The uniform extraction in the event of a fire entails a considerable vacuum. ROM-Drall systems generate this vacuum by having flow sinks in a precise cyclical configuration. A rotation field develops where these vacuum areas overlap, with circumferential speeds close to the centre approaching 250 km/hr and vacuum pressures in excess of 1,000 Pa. This artificially generated whirlwind moves the flow of pollutants into the centre of the swirling mass by means of logarithmic spirals and thence to the extraction points.
Imtech ROM-Drall systems guarantee maximum safety in the event of fire in sensitive buildings such as the new Mercedes-Benz Museum in Stuttgart, and Düsseldorf, Hamburg and Frankfurt am Main airports.
