I am a designer in a medium-size italian CNG recip compressor manufacturer company.
We are compressor manufacturer and packager at the same time: all our compressor (till now) have been driven by small low voltage electric motors (400V 37-400 kW).
Now we decided to offer our customers also the gas engine option: having little or no experience in this field, we contacted some of the primary world gas engine manufacturers.
Despite this, I have a basic question about hazardous area classification in case of compressor + gas engine skids.

If we assume the compressor contained in an enclosure, with given ventilation conditions inside and a certain number of gas emission sources, the compressor itself (seen as a generic gas plant composed of potentially leaking components) generates an hazardous area (e.g. zone 1 having done calculations accordingly to EN60079-10).
Now, if we use an electric motor as a driver, we shall use a proper protection mode to fulfill ATEX requirements (e.g. EEx-d motor).
My question now is: if we use a gas-engine, which - I think - does not carry any ATEX certifications suitable for use in zone 1 (except probably for the instrumentation circuit, which could be EEx-i), should I put compressor and gas engine in two separate rooms? Or can I put them in the same room but loosing ATEX certification of the whole package?
I know that in process plant applications (we made some fuel gas and small pipeline compressors but always EM driven) gas engine and compressor are adjiacent, but I know also that someone else uses the two rooms solution, with the shaft passing through the separating wall by means of a gas-tight bearing group.

In general, I will be very grateful if you can adress me to any links you may know about safety issues (explosion hazards and solutions) related to gas engines/compressor packages.

This is a tough problem that many people are skirting in many parts of the world.  One caution though, if you go with the two rooms approach you are far better to put a genset in one room than to try to run a shaft through the wall.  Running a shaft through the wall can work, but gross alignment in conjunction with foundation settling can be an impossible situation.

With regards to your basic question, good luck/gate valve and tell us how you solve this (none of my clients has been totally successful to this date).

natural gas engines can have exhaust temps into the turbo charger at 1300 F, skin temps on the turbo charger are below 1000F.  Everything else is cooler than 400F.

You can use a water cooled exhaust without a turbo charger and get skin temps of less than about 800F.

The alternator, coils and spark systems are all Class 1 div 2 rated with CSA approved stamp or equal.

there are no hot carbons when using natural gas.  

Batteries are sealed type, but they are to back up the PLC that monitors the compressor and are not used with the engine per se.

One vendor wanted to sell us sparkless belts, so they must exist.

MORE NEWS