Type EBs steam boilers generate saturated or superheated steam. Their primary fuel is biomass in pellets or as wood chips. The technical solutions for this boiler type enable proper combustion of these fuels in the boiler furnace. The pellets and wood chips are incinerated on a step grate. The biomass (pellets or wood chips) is supplied to the boiler plant, stored in tanks and periodically fed to the boiler's day tank. The primary combustion process of the biomass occurs on the inclined step grate, featuring a controlled and forced air supply. The ashes from combustion are shaken off the step grate edge into a hopper with a single wet bottom ash scraping hopper with a discharge to a belt conveyor, which takes the bottom ash out from the boiler house. The boiler flue gas passes an FGT system, which removes particulates.
This type of boiler is designed as a set of two separate blocks on a common steel support structure. The boiler unit stands on a steel support structure made of welded sections, rolled sections, and sheets. An arrangement of boiler service platforms allows access to all boiler units and the operation of auxiliary equipment.
The boiler's first block is formed by the evaporator membrane walls, and the second block is a steam boiler drum with a smoke tube pack. The first flue pass is the furnace chamber, with its bottom closed by the step grate surface, on which the primary combustion of the biomass fuel takes place. The second and third flue gas passes are the flue gas return ducts, made of membrane walls. The third flue gas pass may accommodate optional superheaters. The fourth flue gas pass is the smoke tubes of the steam boiler drum.  The fifth flue gas pass is packed along with the economizer convective tube bundle in a steel sheet casing.
The boiler is delivered with full piping and instrumentation: water gauges, safety valves, starting valves, drain and vent valves, water, pressure and temperature indicators, and ports for remote instrumentation and automatic controls.

Table 1: Examples of the EBs boiler series







Design rating, t/h






Nominal operating pressure, barg




Feed water temp., °C


Saturated steam temp., °C




Design efficiency, %


FG flow resistance, Pa


Flue gas exhaust temp., °C



* Superheated steam max. temp.: 450°C


The parameters of the boiler

Name Value
Fuel Biomass
Construction Smoke tube
Combustion Grate
Energy Steam