Task
To carry out a dust explosion analysis and a general assessment of the explosion risk in the plant.
Develop an explosion-proof aspiration system for an extremely complex process. The protection elements must ensure that the explosion is contained and that the blast wave does not spread to the process equipment, into the work area.
Results
ATEX.CENTER engineers carried out an on-site inspection of the site and studied the design and operating documentation for the aspiration system in operation. What was found out:
- the explosion was caused by an ignition of accumulated metal dust in the aspiration filters;
- the protection of the air ducts consisted of non-return dampers and diaphragms from a European manufacturer;
- The cause of significant damage in the workshop was the penetration of an explosion wave from the aspiration system into the work area;
- The membranes acted correctly and the check valves failed to localise the explosion in the air ducts.
Specialists took the metal dust for analysis. They organised a laboratory explosion test to determine the explosion safety characteristics. An accredited company, VVUU, carried out the research and analysed the results.
The suppliers of gas cleaning, ventilation systems T.A.M.A. AERNOVA and protective equipment RSBP were involved in finding a solution. Together, we developed a process diagram for an explosion-proof aspiration system.
The specialists used literature from the ACGIH - American Conference of Industrial Hygienists.
Results
We have selected and supplied the customer with B-flap 355 check valves (2 pcs.) to cut off the explosion.
The devices are certified according to the requirements of technical regulations for machines and equipment TP TP 010 / 2011, explosion protection TP 012 / 2011; standards EN 16447, EN 15089.
B-flap valves are mounted directly on the air duct before the filter system. Suitable for explosion classes up to St3.
For the production of electrodes with large amounts of metal dust, the choice of B-flap proved to be the optimal solution.
The customer received an explosion-protected version of the aspiration system, which was tailored to the hazards of the steel industry.