How do you keep a fan from being an ignition source in a hydrogen atmosphere?
Hydrogen ignites across a wide band (about 4 to 75% by volume) at a minimum ignition energy near 0.02 mJ, so the fan in the classified zone is engineered not to be a source. We use spark-resistant construction to the AMCA 99 Type A, B or C scheme as the area calls for it: a non-sparking wheel and inlet metallurgy, generous rotating-to-stationary clearances so nothing can rub, and a bonded, earthed assembly to bleed static. We add bearing-temperature monitoring so a failing bearing is caught before it becomes hot. The spark-resistant type and the accessory scope are set to your area classification, not assumed.
What does your ATEX declaration actually cover for hydrogen-safe ventilation?
Where the area classification calls for it, ATEX Zone 2/22 is self-declared per 2014/34/EU (Category 3) — a self-declaration of conformity, not a third-party certification. To be precise: our only third-party certification is ISO 9001:2015. For a hydrogen dilution-ventilation duty we agree the zone, the group and the temperature class with you, build the spark-resistant construction to match, and issue the declaration and technical file for that scope. If your project needs a notified-body certification for a higher category, we tell you that up front rather than imply we carry it.
Our electrolyser needs clean, steady process air. How do you hold the duty point?
We size a high-efficiency backward-curved or aerofoil wheel onto the best-efficiency region of its curve at your stated flow and static, so the fan is not fighting its own characteristic. VFD speed control is our default here because it holds flow as the stack load changes and avoids the throttling loss of a damper at part load. The air path is kept clean with an oil-free bearing arrangement and appropriate coatings so the fan does not carry oil or particulate into the stack. You get a machine that runs on its efficient point across the operating range, not a catalogue fan throttled to fit.
Biogas is wet and carries H₂S. What materials and drainage do you use?
We size the metallurgy and drainage to your gas analysis. Biogas carries hydrogen sulphide and moisture that condense into acid on a cold casing, so we select 316L or coated surfaces on the wetted parts, fit drains at the casing low point to clear condensate, and insulate the casing to hold the wall above the dew point. For saturated electrolyser off-gas that can carry alkaline electrolyte mist we apply the same dew-point and metallurgy logic. The right answer depends on your H₂S content, moisture and temperature, so we engineer it to your gas rather than a default.
Can you build a replacement to match an existing renewable-plant fan's duty and footprint?
Yes. We reverse-engineer to the existing duty point (flow, static pressure, gas temperature, density and gas analysis), the area classification, bearing centres, inlet/outlet orientation and foundation bolt pattern so the unit drops onto the existing base and ducting — whether it is an electrolyser process-air fan, a ventilation fan, a biogas booster or a cooling fan. Made to your installation, not a nearest-catalogue substitute. Send the old GA, the nameplate, the area classification and a curve if you have one, and we match it.
Do you performance-test the fans, and what about AMCA, CE, ATEX and quality certification?
Every fan is performance-tested in-house to the AMCA 210 / ISO 5801 method on our 200 HP VFD test rig, and dynamically balanced to ISO 21940 G6.3 as standard (G2.5 / G1.0 on application). To be precise: that in-house testing is to the AMCA 210 / ISO 5801 method, not AMCA-certified, and we are not an AMCA member; CE is self-declared per 2006/42/EC and 2014/35/EU, and ATEX Zone 2/22 is self-declared per 2014/34/EU (Category 3) where the area classification calls for it — those are self-declarations of conformity, not third-party certifications. Our only third-party certification is ISO 9001:2015.
