Combustion Chamber
COMPONENT 01 — FURNACE / FIREBOX
The primary reaction vessel where biomass or solid fuel is burned on a traveling grate. Hot flue gases rise through the furnace and enter the convective heat transfer zones above. Refractory-lined walls contain temperatures up to 900–1100°C.
CAPACITY
16Ton/hr
TEMP RANGE
900–1100°C
GRATE TYPE
Traveling
LINING
Refractory
FUNCTIONS
Burns solid biomass/fuel on a moving grate at controlled air-fuel ratios
Water-wall membrane tubes absorb radiant heat, generating steam
Primary and secondary air ports control combustion efficiency
Bottom ash discharges via grate drop zone to ash conveyor below
Cyclone Separator
COMPONENT 02 — GAS/PARTICLE SEPARATION
Centrifugal separator that spins the flue gas stream at high velocity. Heavier fly ash particles are flung outward and drop into a collection hopper, while cleaner gas exits from the top and proceeds to the bag filter for final cleaning.
SEPARATION EFF.
≥85%
INLET VELOCITY
12–20m/s
PARTICLE CUT
>10μm
INLET TEMP
~350°C
FUNCTIONS
Uses centrifugal force — no moving parts, low maintenance
Removes coarse fly ash (>10 µm) before the bag filter stage
Collected ash falls into a sealed hopper for periodic discharge
Reduces dust loading on downstream bag filter, extending bag life
Bag Filter
COMPONENT 03 — PULSE-JET DUST COLLECTOR
Fabric filter house containing rows of woven filter bags. Flue gas passes through the bag material, depositing a fine dust cake on the surface. A periodic pulse-jet of compressed air cleans the bags, dropping collected dust into hoppers below.
FILTER EFF.
≥99%
OUTLET DUST
<30mg/Nm³
CLEAN TYPE
Pulse-Jet
INLET TEMP
~150°C
FUNCTIONS
Filters fine particulate matter (<10 µm) from flue gas to meet emission limits
Compressed air pulse-jet cleaning system maintains pressure drop across bags
Collected fly ash drops into sealed hoppers for disposal or reuse
Gas temperature must be maintained above dew point (>120°C) to prevent condensation
Chimney / Stack
COMPONENT 04 — FLUE GAS EXHAUST STACK
Tall steel or concrete exhaust stack that disperses cleaned flue gas high above ground level. Creates the natural draft (negative pressure) that draws combustion gases through the entire flue gas treatment train. Fitted with sampling ports for continuous emission monitoring.
HEIGHT
~20m
DRAFT TYPE
Natural/Mech.
EXIT TEMP
~120°C
MONITORING
CEMS
FUNCTIONS
Dispenses cleaned flue gas high enough to meet regulatory dispersion requirements
Creates natural draft that pulls gas through combustion chamber and treatment train
Equipped with continuous emission monitoring system (CEMS) for NOx, SO₂, PM, CO
Sampling ports allow manual stack testing for regulatory compliance verification
Steam Drum
COMPONENT 05 — STEAM/WATER SEPARATOR
Horizontal pressure vessel at the top of the boiler that separates saturated steam from the steam-water mixture generated in the furnace water-wall tubes. Steam exits from the top; water is recirculated back down to the furnace via downcomers.
DESIGN PRESSURE
13bar(g)
STEAM TEMP
~194°C
STEAM OUTPUT
16T/hr
STANDARD
ASME / EN
FUNCTIONS
Separates saturated steam from the steam-water mixture via gravity and internal cyclones
Acts as the upper header for natural circulation: risers bring hot mixture up, downcomers return water
Feedwater enters via the economizer to replace the steam discharged
Maintains boiler water chemistry; blowdown nozzles remove concentrated dissolved solids
Convection Pass
COMPONENT 06 — ECONOMIZER / SUPERHEATER
The rear gas pass through which flue gases flow after leaving the furnace. Contains tube banks that recover heat for feedwater preheating (economizer) and optionally for superheating steam. Increases overall boiler thermal efficiency.
GAS IN TEMP
~900°C
GAS OUT TEMP
~350°C
DUTY
Economizer
HEAT RECOVERY
~12%
FUNCTIONS
Recovers waste heat from flue gas using crossflow tube bundles
Economizer preheats feedwater before it enters the steam drum, reducing fuel consumption
Optional superheater section raises saturated steam temperature beyond saturation point
Reduces flue gas temperature before the bag filter to safe operating range (<200°C)
ID Fan
COMPONENT 07 — INDUCED DRAFT FAN
Large centrifugal fan positioned after the bag filter that pulls flue gas through the entire system under negative pressure. Creates the system draft required to overcome all duct and equipment pressure drops from furnace to chimney.
TYPE
Centrifugal
PRESSURE
Negative draft
DRIVE
VFD Motor
CONTROL
Auto/Manual
FUNCTIONS
Maintains the entire flue gas system under negative pressure (induced draft)
Variable frequency drive (VFD) adjusts speed to match boiler load
Overcomes pressure drop across furnace, convection pass, cyclone, bag filter and ducting
Works in tandem with FD (forced draft) fan to optimize combustion air balance
Ash Hoppers
COMPONENT 08 — BOTTOM ASH + FLY ASH COLLECTION
Conical collection hoppers positioned below the furnace grate (bottom ash), cyclone, and bag filter (fly ash). Ash is periodically discharged through rotary valves or slide gates into a conveyor or pneumatic transport system for disposal or reuse as soil amendment.
HOPPER TYPES
3 Points
DISCHARGE
Rotary Valve
ASH TEMP
<200°C
REUSE
Soil / Cement
FUNCTIONS
Bottom ash hopper collects grate residue (large, heavy ash) below furnace
Cyclone hopper collects medium-density fly ash (coarse fraction)
Bag filter hoppers collect fine fly ash — highest volume, finest particle size
All hoppers discharge via rotary valves to conveyor belt for transfer to ash storage