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Applications

Induced Draft fans — built for hot, dust-laden, corrosive duty.

ID fans handle the most punishing duty in any gas-handling system: hot flue gas, fly ash, abrasive particulate, acid condensate. They run continuously — and when they fail, the boiler or kiln upstream stops. We build ID fans across cement, power, iron & steel, chemicals and process plants, from package boilers to large utility units, across the full envelope below.

2,00,000CMH max flow
2,000mmWC max static
600 °Ccontinuous gas
400 HPdrive power
Get a quote Talk to engineering
15,000+
fans built since 2011
200 HP
VFD test rig · IS 4894 / AMCA 210
99%
on-time delivery
3
working days to quote — always
DOWNSTREAM OF THE HEAT SOURCE · NEGATIVE DRAFT · THROUGH THE APC TRAIN · TO STACK
What it does

An ID fan does three jobs at once — and the duty is unforgiving.

An Induced Draft fan sits downstream of the heat source: pulling flue gas out, holding the furnace under negative pressure, and pushing it through the pollution-control train (ESP, bag filter, scrubber) to the stack.

  • 01
    Pull

    Enough gas to hold target furnace draft — typically −5 to −25 mmWC at the boiler outlet.

  • 02
    Push

    Through the whole system resistance — ducting, filtration, economizer, stack — which can total 250–2,000 mmWC.

  • 03
    Survive

    The gas itself — 150–400 °C continuous (to 600 °C for kilns), laden with fly ash, sometimes with acid dew-point risk.

INDUCED-DRAFT CENTRIFUGAL FAN Single-width single-inlet — scroll cut away to reveal the impeller inlet expansion joint MOTOR IE3 / VFD GAS IN GAS OUT n 1 2 3 4 5 6 7 8 9 10 1 Inlet cone (bell-mouth) 2 Backward-curved / radial-tipped impeller 3 Spiral volute casing 4 Replaceable AR wear plates (volute throat) 5 Shaft 6 Plummer-block bearings (L10 ≥ 40,000 h) 7 Shaft cooling disc (>400 °C duty) 8 Pedestal / base frame 9 Drive — motor + coupling 10 Outlet flange + duct take-off
Fig. 1ID centrifugal fan — single-width single-inlet, scroll cut away to reveal the impeller. Numbered components keyed below the drawing.
Why it is hard

Three failure modes decide whether an ID fan lasts 2 years or 10.

Hot gas + abrasive particulate + corrosive condensate drive the three things that destroy ID fans. Design for them, and the fan runs 10+ years between major overhauls. Design only for performance, and it fails in 18–30 months.

01 — EROSION

Impeller erosion

Fly-ash particles strike the blades at >50 m/s. Material loss throws the rotor out of balance and cracks the blade root over time.

How we engineer it out

Hard-faced (chrome-carbide) leading edges and impeller geometry chosen to minimise the particle impact angle.

02 — WEAR

Casing wear

Particle-laden gas scours the casing at the volute throat and outlet — the highest-velocity zones.

How we engineer it out

Replaceable, bolted-in AR wear plates on the high-wear zones, with access doors for site replacement — no dismantling the fan.

03 — CORROSION

Acid dew-point corrosion

Below the SO₃ dew point (~120–150 °C) sulfuric acid condenses on the casing wall and eats it.

How we engineer it out

Insulation and heat tracing to hold the wall above dew point, plus corrosion-resistant metallurgy on the wetted surfaces.

How we design for it

Every choice is documented on the GA drawing you sign off — before we cut metal.

We don't sell a catalogue near-fit. The fan is engineered to your gas, temperature, dust load and operating point.

  • Materials & wear protection — MS hard-faced; 4140 alloy + chrome carbide; IS 2062 casing with AR400 wear plates; 316L / Corten / Hastelloy / Inconel for corrosive duty.
  • Wheel geometry — radial-tipped backward-curved by default; straight-radial when fly-ash buildup is the primary failure mode.
  • Draft control — inlet vane damper or VFD. VFD is our default for variable-draft duty — speed control avoids the throttling loss of a damper at part load.
  • Thermal management — fabric/metal expansion joints for growth of order ~25 mm on a long run at 400 °C; shaft cooling disc standard above 400 °C; casing insulation + tracing for acid dew-point service.
Engineered to your duty point

We size the fan where its curve crosses your system — then prove it on the rig.

No catalogue fan forced onto your spec. Your operating point is engineered onto the best-efficiency region of the selected wheel — then verified on the 200 HP VFD test rig before dispatch.

avoid: unstable 0 40,000 80,000 1,20,000 1,60,000 2,00,000 VOLUME FLOW RATE  [ CMH ] 0 500 1000 1500 2000 STATIC PRESSURE  [ mmWC ] 0 25 50 75 100 STATIC EFFICIENCY  [ % ] Fan static pressure System resistance Static efficiency BEP 82% DUTY POINT 1,20,000 CMH · 450 mmWC Fan static pressure System resistance Static efficiency
Fig. 2Representative ID-fan characteristic — fan static pressure, system resistance and static efficiency vs. flow, with the duty point engineered onto the best-efficiency region. Illustrative; every fan is sized to its own duty.
Capability envelope — ID service

What we can supply, and where it stretches on application.

ParameterStandardOn application
Volume flowup to 2,00,000 CMHhigher on enquiry
Static pressureup to 2,000 mmWChigher on enquiry
Continuous gas temperatureup to 600 °Chigher with refractory lining + special metallurgy
Inlet particulate loadingheavy inlet loadinghigher with enhanced wear protection
Drive powerup to 400 HPhigher with custom motor sourcing
Speed600–1,800 RPM typicalper duty + sound limits
Balance qualityISO 21940 G6.3G2.5 / G1.0 on application
Bearing life (design target)L10h ≥ 40,000 h continuouslonger L10 on application

The envelope above covers the great majority of industrial ID-fan duty. For duty beyond it, we engineer to spec and quote on enquiry. Inlet dust loading is duty-dependent — heavy on raw-gas / pre-precipitator and booster-ID service; light on clean-side ID downstream of an ESP or bag filter.

How a Jitamitra ID fan is specified

Specified, not picked from a shelf.

The same engineering language carries from your enquiry to the GA drawing to the nameplate — expressed in the standard AMCA conventions.

Specification fieldOptions
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 / inletSWSI (single width, single inlet) default for ID duty; DWDI (double width, double inlet) for high flow at moderate pressure.
Wheel typeRadial-tipped backward-curved (default, best efficiency) / straight-radial (when fly-ash buildup dominates) / backward-curved (clean-gas, high-efficiency duty).
Class (by pressure / outlet velocity)Class I / II / III selected from the duty point on the pressure-vs-outlet-velocity limits; higher class = heavier construction for higher pressure and tip speed.
Materials of constructionMS (standard) / IS 2062 casing with AR400 bolted wear plates / hard-faced (chrome carbide) or 4140 wheel for abrasion / 316L, Corten, Hastelloy or Inconel for acid dew-point and corrosive gas.
DriveDirect-coupled / V-belt / VFD (default for variable-draft control). Drive up to 400 HP across the envelope; speed typically 600-1,800 RPM.
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.
Accessories & high-temp scopeInlet vane damper or VFD control; fabric or metal expansion joints (thermal growth to ~25 mm at 400 °C); bolted-in AR wear plates and access doors; shaft cooling disc (standard above 400 °C); casing insulation and heat tracing for acid dew-point service; drain and inspection doors.
The proof, not the promise

We test before we ship — and you're welcome to witness it.

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.

  • Customer-witnessed FAT on request — at no extra cost
  • Rotors balanced to ISO 21940 G6.3 as standard (G2.5 / G1.0 on application) before they leave the floor
  • Full NDT in-house — DP, MPI, UT, RT — to what the duty demands
30+ INDUSTRIES · 45 APPLICATION / DUTY TYPES
Where our ID fans run

Proven where the gas is hottest and dirtiest.

Iron & Steel

Sinter-plant ID, blast-furnace gas cleaning, reheating-furnace flue gas.

Cement

Kiln ID, pre-heater fans, raw-mill ID.

Power Generation

Boiler ID (utility + cogen), ESP-downstream fans.

Chemicals & Petrochem

Process-boiler ID, RTO / RCO downstream fans.

Foundry & Forging

Cupola ID, induction-furnace fume, heat-treatment ID.

Food Processing

Drying-furnace ID for spray driers and roasting lines.

Pharmaceuticals

Solvent-recovery and drying-furnace ID fans.

Your process

45 application/duty types engineered. Tell us yours.

Standards & conformity

Stated precisely — because procurement checks.

What our marks mean, in the words that survive an audit.

Performance

Tested to the AMCA 210 / ISO 5801 method, in-house on our 200 HP VFD rig. Tested-to-method — not AMCA-certified.

Quality system

ISO 9001:2015 — third-party certified. Our only third-party certification.

CE conformity

Self-declared per 2006/42/EC + 2014/35/EU (Module A). A self-declaration, not a notified-body certificate.

ATEX conformity

Self-declared, Zone 2/22, Category 3, per 2014/34/EU, where the area classification calls for it.

Oil & gas duty

Designed and built to API 673 as project-specific scope.

Welding

ASME Sec IX qualified welders + WPS for every joint.

Balance

ISO 21940 — G6.3 minimum, G2.5 / G1.0 on application.

Vibration

ISO 20816 evaluation; ISO 14694 for fan-specific limits.

Lead time & process

From enquiry to a tested fan on your dock.

StageStandard dutyAPI-673 / engineered
Offer / quotation3 working days — always7–10 working days
GA drawing for approval2–3 weeks from PO3–4 weeks from PO
Manufacture + balance + paint6–10 weeks10–14 weeks
Performance test + witnessed FAT~1 week1–2 weeks
Order-to-dispatch (total)9–14 weeks14–20 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.

Questions engineers ask

The eight we hear most before a PO.

What is the maximum gas temperature your ID fans handle?
Continuous duty up to 600 °C across the envelope, with most ID fans running 150-400 °C. Above 400 °C we fit a shaft cooling disc as standard (available from 350 °C on request), plus metal or fabric expansion joints sized for the thermal growth (up to ~25 mm at 400 °C). The fan is built for your stated gas temperature and excursion case, not a generic rating.
How do you protect the impeller from fly-ash erosion?
Three measures, specified to your dust loading. Hard-faced (chrome carbide) leading edges or a 4140 / chrome-carbide wheel on abrasive duty; bolted-in AR400 wear plates at the volute throat and outlet with access doors for replacement; and wheel geometry chosen for the dust — radial-tipped backward-curved as default, straight-radial when fly-ash buildup dominates. The wear parts are replaceable in place, not welded in.
We have high-sulfur gas and acid dew-point risk. What materials do you use?
Below the acid dew point (typ ~120-150 °C) we keep the casing above dew point with insulation and heat tracing, and select corrosion-resistant materials for the gas: Corten, 316L, or higher alloys (Hastelloy / Inconel on request). The right answer depends on your SO₂/SO₃ and moisture, so we size the material and the dew-point margin to your gas analysis, not a default.
Can you build a replacement to match our existing fan's duty and footprint?
Yes. We reverse-engineer to the existing duty point (flow, static pressure, temperature, density), bearing centres, inlet/outlet orientation and foundation bolt pattern so the unit drops onto the existing base and ducting. Made to your installation, not a nearest-catalogue substitute. Send the old GA, nameplate and a curve if you have one and we'll match it.
What control and accessory scope comes with the fan: damper, VFD, expansion joints?
Scope is specified per duty. Draft control by inlet vane damper or VFD (VFD is our default for variable-draft service, since speed control avoids the throttling loss of a damper at part-load). We supply matched expansion joints (fabric or metal), bolted-in wear plates, access doors, drain, and shaft cooling disc where temperature requires. Tell us the battery limit and we quote the accessories inside it.
How fast can you ship a shutdown replacement?
Shutdown replacements ship within 6 weeks of a clean PO. A standard engineered ID fan runs roughly 9-14 weeks order-to-dispatch (GA approval 2-3 weeks, manufacture, balance and paint 6-10 weeks, test and FAT 1 week). For an emergency we prioritise the wheel and bearings and confirm a dated commitment against your shutdown window — a real date, not a placeholder.
Do you performance-test before dispatch, and can we witness it?
Yes. 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). The test and FAT take about a week and are customer-witnessed on request. You see the curve and the balance report before the fan leaves the floor.
What about API 673, CE and ATEX requirements?
We design and build to API 673 for oil and gas duty as project-specific scope (allow 7-10 working days for the offer). 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. To be precise: those are self-declarations of conformity, not third-party certifications; our only third-party certification is ISO 9001:2015.
Across the range

Where the ID fan fits — the fans that run it, its sibling duties, and the industries it serves.

The same engineering, viewed three ways — by fan family, by duty, and by industry. Follow the cross-references.

Fan families

Jitamitra RadialJitamitra Backward-Curved Plate

Applications

Forced Draft (FD)Primary Air (PA)Dust extraction (dirty side)Kiln / furnace exhaustESP / baghouse main fanGas Recirculation (GRF)

Industries served

Thermal PowerCement & LimeIron & Steel / MetalsPulp & PaperPollution Control / APC OEMWaste-to-Energy / Incineration
Take it further

Specs an engineer can use — not a brochure.

ID Fan datasheet (PDF)Capability envelope, materials matrix, designation guide, standards — sent to your inbox on enquiry.ON ENQUIRY · JEEPL-DS-IDFAN-R01 GA & STEP / DWGGeneral-arrangement and 3D model for your duty, on request.ON REQUEST · GA + 3D MODEL Capability statementWho we are, what we run, the test rig, the record.PDF · GENERAL
Engineer to engineer

Send us the duty point.
We'll quote in 3 working days — always.

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