If your machine is using an oil-based coolant it is likely that the machines cabinet will become full of an oily mist vapour and for machines this also means the fitment of a mist extraction system (which also needs individual protection).
Unfortunately, in the event of a fire there is a high risk that this oily vapour inside the machine will ignite and will result in an explosion inside of the machines cabinet.
Whilst machines cabinets are fitted with safety glass and are sturdy, they are also well sealed to prevent coolant escaping outside of the machines working zone. This means that when an ignition occurs inside of the cabinet the resulting force has nowhere to go - thatís highly dangerous as the forces then produced are extreme.
In the worst-case scenario, the resultant blast could literally blow the machines doors outwards and straight into the area where machine operators are likely to be standing. For this reason, machines are fitted with pressure relief flap devices on the roof of the machine.
The task of these flaps is that in the event of an explosion the flaps open and will direct the resulting explosion and flames upwards though the roof of the machine and therefore away from operators. Care must be taken to consider the distance between the roof of the machine and the factories ceiling because itís very important to ensure that the resultant blast, once directed upwards and outwards, cannot easily hit the ceiling and then be directed back downwards towards operators.
Kraft & Bauer UK provides (supply only) two solutions to the problem of explosions inside machine tools. The standard pressure relief flaps are able to control explosive forces where the gap between the top of the machine and the ceiling is 5 meters or over.
For information on the two standard solutions click here.
The other solution is where the gap between the top of the machine and the ceiling is under 5 meters and that is when the advanced Oil-Ex Box is used. This has been designed specifically for machine tools and captures the blast and flames and rather than containing them (that would result in a blast occurring) it slows the forces down and reduces them to ensure that when they are released, they are done so at a much lower force.
To download information on the Oil-Ex Box click here.
Photo Before flaps close
Warning: Itís very important that you check the roof of your machines and make sure that the top surfaces around the flaps are not oily and the flap themselves are kept clean and free from debris.