High pressure sodium lights

[mech225]

Can anyone comment on the use of high pressure sodium (HPS) lights and use of them in conveyor tunnels. The tunnel has dust due to the products being conveyed. Products like coke, quartz, chromium oxide. Does the light have any affect on the dust or can an expolsion occurr. Will the light travel through dust. The dust is not thick as in smog. People do work in the tunnel and use a dust mask.

Thanks

Mech225

 

[DRWeig]

As long as the tunnel is not classified as a dust explosion hazard (sounds like it is not), HPS should be fine. Size them up to accommodate the dusty air, and be sure to alternate phases to prevent strobe effect on the conveyor equipment.

If the tunnel is classified as hazardous, get an appropriately rated explosionproof fixture.

You do need to find out about the classification. Without seeing it, I'd be inclined to call it a dust explosion hazard since you're bouncing that stuff around on a conveyor.

Wait for others to respond - another eng-tipper may have experience in a similar application.

Best to you,

Goober Dave

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[waross]

Coke dust is pure carbon. Like coal dust without inert impurities. Coke dust is at least as hazardous as coal dust.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[ScottyUK]

HPS isn't fundamentally wrong, but you'll need an appropriately-certified luminaire for the hazardous area. In the UK mining equipment is certified differently to surface applications, so a different set of regulations apply. That may also be the case elsewhere in the world, so do check.

 

[jmbelectrical]

As others have pointed out, it's technically acceptable to use an HPS luminaire if it's rated appropriately. Having said that, while HPS luminaires have excellent efficacies, their color rendering properties are extremely poor (Somehwere in the vicinity of 20 to 30 percent). If this is a task/detail-oriented application where color discrimination is important, consider the use of metal halide or LED lamp sources.