The Backward-Curved Plate family is the one we build most. Flat steel-plate blades set on a backward-curved pitch give you medium-to-high pressure and good efficiency, with the robustness to take light dust an aerofoil wheel would never survive. It is the default first pick for forced-draft, primary and secondary air, combustion and process air, bag-filter draught and light-dust ID across process and power plants — engineered to your duty point, not selected from a fixed catalogue.
The blades are flat steel plates set on a backward-curved pitch — simpler and tougher to fabricate than a shaped aerofoil, and run at a higher tip speed (140 m/s, Class 3–4 build). That combination is the practical middle of the range: it holds good efficiency while generating more pressure for a given size than a curved-blade fan, and it still leans backward, so the power curve cannot overload the motor.
The plate blade at 140 m/s tip develops medium-to-high static — more pressure per unit size than a curved-blade wheel, and family-served to 2,000 mmWC on the smallest wheels.
Backward-leaning plate keeps static efficiency high — close behind the aerofoil and curved-blade wheels — so the running-cost penalty over an aerofoil is small while the pressure and dust headroom are large.
The solid plate blade tolerates light dust — bag-filter draught, process air and light-dust ID — where a thin aerofoil blade would erode in weeks.
Every wheel form is a trade-off between efficiency, pressure and dust tolerance — you cannot maximise all three at once. The backward-curved plate is chosen when you need two of the three at once: pressure and light-dust ruggedness, with efficiency given up only at the margin. Push past its limits and the right answer is a different family — and we will tell you which.
Forced-draft, combustion-air and primary-air duty often needs more static than a clean curved-blade wheel can give at a sensible size — but not the extreme pressure of a heavy radial.
How we engineer it outThe plate blade runs a 140 m/s Class 3–4 tip — more pressure per unit diameter than the curved Backward-Curved family, and a served record to 2,000 mmWC on the smallest high-pressure wheel.
Bag-filter draught, process air and light-dust ID carry enough particulate to erode a thin hollow aerofoil blade — but not enough to justify the efficiency penalty of a full radial.
How we engineer it outSolid steel-plate blades tolerate light dust, and the flat plate is straightforward to wear-protect with leading-edge hardfacing and replaceable scroll liners when dust creeps toward the family's gate.
Reaching pressure and dust tolerance by jumping straight to a radial wheel costs you efficiency — and on a fan running thousands of hours a year, that is real electricity.
How we engineer it outBackward-leaning plate holds peak static efficiency close to the curved-blade family's, so you keep most of the running-cost benefit while gaining the pressure and dust headroom.
We don't sell a catalogue near-fit. The wheel is selected near best efficiency for your flow, pressure, temperature and dust, and the construction is specified to your gas and area classification.
No catalogue fan forced onto your spec. With seven wheels to choose from, your operating point is engineered onto the best-efficiency region of the closest-matched plate wheel — then verified on the 200 HP VFD test rig to the AMCA 210 / ISO 5801 method before dispatch.
| Parameter | Standard | On application |
|---|---|---|
| Volume flow | up to 2,00,000 CMH | higher on enquiry |
| Static pressure | family to ~1,562 mmWC | served to 2,000 mmWC (small-wheel high-pressure build) |
| Continuous gas/air temperature | up to 600 °C with HT construction | shaft cooling disc above ~150 °C; metallurgy to duty |
| Inlet dust loading | light dust — bag-filter draught, process air, light-dust ID | wear-plating + liners near the gate; heavier dust → radial-tip / radial family |
| Peak static efficiency (family) | high for the range (exact figure shared with your enquiry) | duty-dependent; wheel selected near BEP |
| Drive power | up to 400 HP | higher with custom motor sourcing |
| Balance quality | ISO 21940 G6.3 | G2.5 / G1.0 on application |
| Bearing life (design target) | L10h ≥ 40,000 h continuous | longer L10 on application |
The envelope above sits inside Jitamitra's company-wide publishable ceiling (2,00,000 CMH / 2,000 mmWC / 400 HP / 600 °C). The family's own character — a ~1,562 mmWC software static ceiling with high static efficiency — is from the internal range study; the 2,000 mmWC point is a genuine served-above-software record (three small-wheel high-pressure units, 2022, motor-power checked), not a catalogue claim. Once dust becomes more than light this is the wrong duty for this wheel — we move you to the radial-tip or radial family so the fan lasts.
The same engineering language carries from your enquiry to the GA drawing to the nameplate — expressed in the standard AMCA conventions.
| Specification field | Options |
|---|---|
| Arrangement (AMCA 99) | Arr. 1 (overhung, fan bearings) / Arr. 4 (direct, motor on base) / Arr. 8 (overhung on common base) / Arr. 9 (overhung, motor side) / Arr. 10 (overhung, motor inside base) — selected by drive, access and temperature. |
| Width / inlet | SWSI (single width, single inlet) standard across most wheels for pressure; DWDI (double width, double inlet) on the high-flow wheel for high flow at moderate pressure. |
| Wheel type | Backward-curved plate (flat steel plate on a backward-curved pitch) — the medium-to-high-pressure, light-dust workhorse; one step up in pressure and dust headroom from a curved/aerofoil wheel, one step down in dust tolerance from a radial. |
| Class (by pressure / outlet velocity) | Class I / II / III selected from the duty point on the pressure-vs-outlet-velocity limits; the plate blade runs a Class 3–4 (140 m/s) tip, so higher class = heavier construction for higher pressure and tip speed. |
| Materials of construction | MS (standard) / SS304 or SS316 full or airstream for corrosive process air / FRP (F suffix) for wet corrosive gas / Corten or duplex per duty / wear-plated (WP) leading edges and replaceable scroll liners for light-dust service. |
| Construction suffix | HT (high-temperature construction + shaft cooling disc for hot process air) / SR (spark-resistant, AMCA 99 Type A/B/C + self-declared ATEX, for solvent and combustible-dust zones) / F (FRP airstream) / WP (wear-plated for light dust). |
| Drive | Direct-coupled / V-belt / VFD (default for variable process-air duty, with shaft-earthing ring). Drive up to 400 HP across the envelope; shaft cooler fitted above ~150 °C. |
| Discharge & rotation (AMCA orientation) | Rotation CW or CCW (viewed from drive side) with discharge angle per AMCA — e.g. TH/BH/UB/DB — set to match your duct take-off and installed footprint. |
Every job's performance is verified at our works on the 200 HP VFD test rig, to the AMCA 210 / ISO 5801 method, before dispatch.
Forced-draft (FD), primary air (PA) and secondary / overfire air (SA) on the boiler fan suite.
Coal-mill primary air and clean-side process-air duty.
Blast-furnace combustion air and high-pressure process-air blowers.
Process and combustion air; API 673 process fans for oil & gas service.
Solvent and paint-booth exhaust on spark-resistant (SR) construction; process air.
Spray / fluid-bed / flash drying and process ventilation.
Recovery-boiler and general process-air fans.
7 plate wheels, sized to your duty. Tell us yours.
What our marks mean, in the words that survive an audit.
Tested to the AMCA 210 / ISO 5801 method, in-house on our 200 HP VFD rig. Tested-to-method — not AMCA-certified.
ISO 9001:2015 — third-party certified. Our only third-party certification.
Self-declared per 2006/42/EC + 2014/35/EU (Module A). A self-declaration, not a notified-body certificate.
Self-declared, Zone 2/22, Category 3, per 2014/34/EU, where the area classification calls for it.
Designed and built to API 673 as project-specific scope.
ASME Sec IX qualified welders + WPS for every joint.
ISO 21940 — G6.3 minimum, G2.5 / G1.0 on application.
ISO 20816 evaluation; ISO 14694 for fan-specific limits.
| Stage | Standard duty | API-673 / engineered |
|---|---|---|
| Offer / quotation | 3 working days — always | 7–10 working days |
| GA drawing for approval | 2–3 weeks from PO | 3–4 weeks from PO |
| Manufacture + balance + paint | 6–10 weeks | 10–14 weeks |
| Performance test + witnessed FAT | ~1 week | 1–2 weeks |
| Order-to-dispatch (total) | 9–14 weeks | 14–20 weeks |
Shutdown-driven replacements: we have shipped fans within 6 weeks of a clean PO. Tell us your shutdown window and we commit to a dated plan.
The same engineering, viewed three ways — by fan family, by duty, and by industry. Follow the cross-references.
No model numbers needed. Give us the operating conditions — flow, static, gas temperature, composition, particulate, and any tender standard — and our application engineers size the fan and quote it. Attach a spec or GA if you have one.
+91 90110 09155 · mihir.jitamitra@gmail.com