DESIGN COST CUTTING & FAILURES IN BOILER

Boiler is given guarantee of engineering/design for life span of around 25 years but trouble starts within a short time period due to engineering issues comes on surface.

In my professional career, I understand that, few changes are made purposefully against essential requirement in the engineering norms for cost cutting in boilers, auxiliaries to re-sell products against failures and get after sales services / spares business from customer.

Then they suggest few changes in engineering / design to re-sell product. Later, they implement the Improved Design to get business, while it should have come in the first stage of execution.

If Not Specified in Contract & ignored by Consultant, SELLER will try to reduce cost and quality by below mentioned points:-

  1. Reduce List of mandatory spare items
  2. Reduce furnace height upto maximum extent limit,
  3. Change in type of boiler support like Top support, Bottom Support, Centre support
  4. Reduce Staircase width 1000 mm upto operating platform & above 750 mm only
  5. Supports Cantilever for soot blower / other platform upto 3 meters
  6. Coal spreading by Pneumatic Spreader in Grate Boiler to avoid Mechanical spreader
  7. Reduce Header length by placing valves in offset position at header
  8. Water wall panel / Economiser tube thickness reduction to 3.66 mm from 4.0 mm. Initially, in old supplied boilers, water wall tube thickness was 4.5 mm.
  9. Increment in Water wall panel tube pitch for 63.5 mm O.D tubes from 88 mm to 100 mm
  10. Pipe / Header / Down comer / Riser size reduction by increasing velocity & avoiding unbalance factor in calculation. Change in Material grade by avoiding unbalance factor.
  11. Avoid Rifle tube selection for bed coil in AFBC Boiler.
  12. Change in - Air nozzle design of furnace bed, Refractory material & it’s application, Cyclone separator design, Ash cooler design, Pollution control equipment sizing, Changes in number of Essential Instruments, Height of canopy above steam drum, Secondary Air distribution-Over Fire Air, etc
  13. Changes in - Circulation Ratio of boiler, Furnace Bed height, Flue gas residence time in furnace, High Water Flow in Spray system for Steam Temperature control

Read Example on Boiler Feed Pump (BFP) & Deaerator Selection @Cost Cutting, is described in details in attachment