Explosion Safety for conveyors
The diversity of conveyors does not allow for a standard protection concept
Various measures are used to prevent explosions without installing protective equipment:
- limited conveying speeds,
- suitable material pairings
- safety-relevant designs
Thus, the risk of combustion is reduced by the conveyors themselves.
Open, non-encased belt conveyors are considered as the least critical, since the conveyed material usually does not become airborne and does not have any direct contact with hot surfaces.
As opposed to trough conveyors and worm conveyors: Depending on the degree of fineness, moisture content and dust formation probability of the material, the conveying principle and the conveying speed of the system parts, there will be different explosion risk levels which depend on the zone partitioning and the ignition danger evaluation.
As the minimum protection it must be ensured that explosions that occur in neighbouring parts of the system, are prevented from spreading through other conveyors. By default, ATEX-tested chemical barriers, quench valves or check valves are used.
Pipe conveyors can also be converted into a decoupling protective device in-house with the help of expert guidance. For this purpose, a certain amount will be extracted at the auger spiral. The feasibility of this measure particularly depends on the flow of the material, and the installation length of the auger, and will ideally lead to the conveyed product filling the entire pipe cross-section in this area and thus forming a product plug. This automatically fills during normal operation and functions as a decoupling element in the event of an explosion, since it prevents propagation of the explosion into further plant parts.
This is different for trough screw conveyors: here, the open, product-filled cross-section and the strength requirements usually lead to the need for chemical barriers. These are controlled by pressure or infrared detectors which detect a resulting explosion or flames, and trigger the bottle of extinguishing agent. The fire extinguishing agent, which is then discharged will cool and stop the flame. However it can often be more useful and cost-effective to install tested explosion safety systems especially in outdoor areas.
You are using the following conveyors in your production, and need expert consulting regarding Explosion Safety?
- Trough chain conveyor
- Screw conveyors
- Conveyor belt
- Belt conveyor
- Tube chain conveyor
Call us, we will gladly provide with a consultation.
The overall picture counts:
The protection of individual system components is only as good as the protection of the entire system. Pay particular attention to having sufficient decoupling devices, and the protection against “over engineering”. Only if the entire system is observed, and the individual protective measures are aligned to each other, will your Explosion Safety concept be safe AND economic.
We therefore offer you comprehensive protection concepts and on-site consulting, on how you can implement organizational measures to achieve a greater degree of safety.