1 to 10 t/h,682 to 6 793 kW The BWD is a 3-pass semi-wet backfire tube boiler exclusively designed by BABCOCK WANSON. High efficiency, 95% with optional economiser > The optimised matching of the BWD boiler shell and the Babcock Wanson burnerenables an efficiency of 95% with economiser. A constant efficiency is obtained from 30 to 100% load over the whole modulation range thanks to stable combustion dueto the geometry of the burner head. Sturdiness and long lifeassociated with its design > The flue gas reversal chamber, locatedco-axially with the furnace tube, ensures optimum distribution of the mechanical stresses which contributes to the long lifeof the boiler shell, notably for significantstart/stop cycles. Efficiency PACK without ECONOMISER with ECONOMISERwith ECOSTEAM Easy accessibility of thetubes provides better and lower maintenance cost > Efficiency % 7525507510080859010095 The outer section of the transfer chamberwhich is cooled by the water, is equipped with a double compartment. This particu- lar BABCOCK WANSON design improves the heat transfer and allows direct access to the first tube nests. This eliminates the frequent problem of fragility affecting the tie rods on conventional wet back boilers. Non contractual values Steam load % Steam quality > The steam separator located inside the boiler shell, under the steam outlet, and the rapid burner response time, ensure that the dryness guarantee is 99.5%. Operating modes > Equipment options include control and instrumentation for either fully manned, supervised or fullyunattended operation. Compactness andflexibility > The centred fire-box and the optimiseddistribution of the second and third pass convection tubes enables best possible use of site space. BABCOCK WANSONburners provide a wide operating range,with turn down ratios of up to 8:1 when firing on gas. size="-2">