Can you supply the complete boiler draught set, or only one fan?
The complete set. We have executed 66 thermal-power duties spanning induced draught, forced draught, primary air, secondary and overfire air, gas recirculation, the ESP or baghouse main fan and the FGD booster. Each fan is engineered to its own gas, temperature, dust load and efficiency target — the hot ash-laden ID and the clean high-efficiency FD are different machines — but they come from one partner on one engineering convention across the unit, so the fans, wear parts and drives carry one language across the island.
Our coal is high-ash. How do you protect the ID fan wheel and casing?
Indian coal running 30 to 45 percent ash is the most common cause of ID-fan wear, so we protect three ways sized to your ash loading. A rugged radial wheel that sheds ash and resists erosion; chrome-carbide hard-facing on the blade leading edges and high-wear zones; and bolted-in, replaceable AR wear plates and liners at the volute throat and inlet with inspection and cleanout doors, so worn parts change out in place. The wear scope is replaceable, not welded in — which is what keeps the ID fan running a full boiler campaign between overhauls.
The FD and PA fans run continuously. How do you keep the auxiliary power draw down?
Fan power is a large slice of a plant's auxiliary consumption, so on the clean-side air fans we engineer the duty point onto the best-efficiency region of a backward-curved plate or aerofoil wheel rather than force a catalogue fan near it. For variable-load air fans we make VFD speed control the default, so part-load draft comes from trimming speed, not from throttling loss across a damper. Every point of static efficiency and every avoided damper loss is power the plant does not burn for the life of the unit. We size it to your load profile, not a nameplate rating.
What is the maximum gas temperature you handle on an ID or gas-recirculation fan?
Continuous duty up to 600 °C across the envelope. Clean-side ID runs 130 to 180 °C, but upstream ID and gas-recirculation duty runs much hotter. Above about 350 °C we fit a shaft cooling disc to keep heat off the bearings, keep the bearings outside the airstream, and add expansion joints for the thermal growth (a 1 m shaft grows about 7 mm from cold to 600 °C). The fan is built for your stated gas temperature and excursion case, not a generic rating.
We have acid dew-point risk on the back end and a wet FGD. What materials do you use?
We size the metallurgy and the dew-point margin to your gas analysis. Below the acid dew point (typically 120 to 150 °C on the ESP and clean-side ID) we keep the casing wall above dew point with insulation and heat tracing and select Corten or 316L on the wetted surfaces. Downstream of a wet scrubber the FGD booster handles saturated gas that condenses continuously, so we step up to higher alloys and add drains and access doors where condensate collects. The right answer depends on your SO₂/SO₃, chloride and moisture, so we engineer it to your gas, not a default.
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). Because the rig runs cold air, hot flue-gas operation is extrapolated by fan-law correction for density. To be precise: that in-house testing is to the AMCA 210 / ISO 5801 method, not AMCA-certified; 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.
