Pressure aerator
A pressure ventilator , also called high pressure (be) ventilator or overpressure ventilator , is a fire-fighting device that is used to make smoke-free rooms or houses smoke-free or to keep non-smoke-free building parts smoke-free.
features
A pressure aerator is basically a fan that is set in motion either by a gasoline engine , an electric motor or a water drive.
Electric fans are also available in explosion-proof versions. Contrary to popular belief, water-powered fans generally have no explosion protection according to ATEX . The water fan does not have a gasoline engine or an electric motor, but there are also moving parts that can generate static electricity. Even fans with antistatic components are not explosion-proof if normal fire hoses are used for their operation.
Fans for overpressure ventilation should not be confused with so-called turbo or injector fans , which work as pure flow machines according to the injector principle. Turbo fans are often very compact and differ from positive pressure fans in terms of their propeller shape and the number of propeller blades (small, turbine-like propellers, often with 12 to 14 blades, in contrast to positive pressure fans, which work with fewer and longer propeller blades).
commitment
The device generates a flowing air cone during operation. This air cone is used to cover the so-called entry opening (usually the front door or a window on the ground floor). This creates an overpressure inside the house that drives the smoke out of the building. The prerequisite for this is that there is a corresponding outlet opening , which should be about 1.5 times the size of the inlet opening . These openings can be permanently installed smoke ventilation openings (as is usual in public buildings), or a window that may have been opened beforehand by the attack force .
The pressure aerators can also be used in the course of tactical ventilation to prevent a flashover (ignition) or a smoke gas explosion and are thus an essential part of modern fire fighting. Pressure ventilation was introduced in the USA , because the local building regulations often lead to burns and smoke gas explosions in the event of a fire. The overpressure generated and the air drawn in with it push the smoke out into the open air, which prevents smoke from igniting. However, the pressure must be strong enough not to have the opposite effect. The main advantages for the emergency services are the better view in the building and smoke-free areas, through which people can be rescued more easily. This use can be further optimized in combination with a mobile smoke trap. The lower heat load also has a positive effect, which noticeably increases the operating times and personal well-being.
Despite the many advantages in fire use, pressure ventilation can also cause great damage if not used properly. If the airflow is channeled incorrectly or inadequately, the smoke from the fire is distributed throughout the building. The air supplied can also support the spread of the fire if, for example, flying sparks occur in air conditioning systems inside the building. Not to be neglected is the risk of injury and contamination from objects being blown up.
When using pressure ventilation, the following principles apply:
- The operation must be ordered by the chief of operations
- Framework conditions must be met (exhaust opening, ducting)
- Use only in conjunction with a breathing apparatus . There must be close communication with the team about the procedure (e.g. start and end of ventilation), as this can otherwise put the team in serious danger.
Hints
The pressure ventilator supplies the building with fresh air. There is a risk that a smoldering fire will be rekindled by the new oxygen supply. However, the aerator also promotes the removal of dangerous (because flammable) gases such as carbon monoxide , so it can also be used during deployment to support the troops ahead. On the other hand, the incorrect use of pressure ventilators with combustion engines, but without exhaust gas routing, causes engine exhaust gases to enter the ventilated building, which in particular can raise the concentration of carbon monoxide to health-endangering levels.
A disadvantage of gasoline-powered pressure aerators is the high volume of the device. Communication directly next to the device, which is usually placed in front of the entrance opening to the building, is not possible or is very difficult.
literature
- Roy Bergdoll, Sebastian Breitenbach: Die Roten Hefte, Issue 1 - Burning and Extinguishing . 18th edition. Kohlhammer, Stuttgart 2019, ISBN 978-3-17-026968-2 .
Web links
Individual evidence
- ↑ Fire Brigade Magazine , Special Issue: Behavior in Internal Attacks , Chapter 7: Fans march .
- ↑ Trainers for the volunteer fire brigades - training to become a squad leader . Neckar-Verlag, Chapter 13 Ventilation of Buildings.
- ^ Sabine Sickinger, Stefan Sellmeier, Oliver Meisenberg, Sebastian Schöttner: Carbon monoxide poisoning by ventilation devices? In: fire protection - German fire brigade newspaper . No. 7 , 2011, p. 538-540 .