7/30/2019 2009-06-17 Ash Handling
1/4
Bua Sommai Biomass Co., Ltd., Thailand
9.0 MWe Biomass Based Power Plant Page 1 of 4
ASH HANDLING SYSTEM DESIGN FOR THE POWER PLANT
1.0 BOILER DATA:Description Parameters
Type
Bi-drum, balanced draft, natural
circulation, semi-outdoor type,
travelling grate boiler.
Boiler Capacity (MCR) 50 TPH
Steam pressure at Main Steam
Stop Valve Outlet66 kg/cm2 (g)
Steam temperature at Main
Steam Stop Valve Outlet485 + / - 5 Deg C
Feed water temp at Economiser
Inlet130 Deg C
Feed water temp at Deaerator
Outlet130 Deg C
Design Fuel 100% Rice Husk
Boiler efficiency (GCV basis) 80 %
Heating surface area 2538 Sq. m
Travelling grate surface area 29.77 Sq. m
2.0 FUEL DATA:Fuel : Rice Husk
Gross Calorific Value : 3400 kcal/kg
Bulk density : 120 kg/m3
7/30/2019 2009-06-17 Ash Handling
2/4
Bua Sommai Biomass Co., Ltd., Thailand
9.0 MWe Biomass Based Power Plant Page 2 of 4
Fuel Ultimate Analysis, % by weight
Sl. No ConstituentWet basis
(% by weight)
Dry basis
(% by weight)
1 Carbon 36.40 39.20
2 Hydrogen 3.58 3.86
3 Oxygen 37.99 40.92
4 Sulphur 0.04 0.043
5 Nitrogen 0.55 0.59
6 Chlorine 0.08 0.09
7 Moisture 7.15 0.00
8 Ash 14.21 15.30
Fuel Consumption during Normal operation
(9.0 MW 39 tph steam output from Boiler) : 9797 kg/hr
Fuel Consumption during MCR operation (50 tph) : 12560 kg/hr
3.0 FLUE GAS DATA FROM COMBUSTION:3.1 Flue Gas Analysis:
S.No. Constituent % By Vol.
1 CO2 14.680
2 H2O 12.743
3 O2 4.636
4 N2 67.925
5 SO2 0.017
3.2 Volume of flue gas at MCR condition:Wet basis : 62714 Nm3/hr
Dry basis : 62029 Nm3/hr
7/30/2019 2009-06-17 Ash Handling
3/4
Bua Sommai Biomass Co., Ltd., Thailand
9.0 MWe Biomass Based Power Plant Page 3 of 4
3.3 SOx generation at MCR condition (Dry basis)
Basis : 7% O2 dry basis
Excess Air : 50 %
Flue gas volume = 68099 Nm3/hr
Suphur content in fuel = 0.043 %
Fuel consumption = 12560 kg/hr
SO2 generation = 10.80 kg/hr
SOxquantity at MCR condition = 158.59 mg/Nm3
= 55.45 ppm
3.4 NOx generation at MCR condition (Dry basis):NOx generation :
7/30/2019 2009-06-17 Ash Handling
4/4
Bua Sommai Biomass Co., Ltd., Thailand
9.0 MWe Biomass Based Power Plant Page 4 of 4
Density of flue gas = 0.864 kg/m3
Flue Gas volume from boiler to ESP = 95088 m3/hr
Density of flue gas at NTP condition = 1.31 kg/Nm3
Gas volume from boiler to ESP = 62714 Nm3/hr
Ash content in fuel = 14.21 %
Fuel consumption = 12560 kg/hr
Total Ash generation = 1785 kg/hr
Bottom Ash quantity (40%) = 714 kg/hr
Fly Ash quantity (60%) = 1071 kg/hr
Inlet dust loading to ESP = 17.00 gm/Nm3
Outlet dust concentration = 100 mg/Nm3
Total ash collected in ESP = 1065 kg/hr
ESP Collection efficiency = 99.41 %
6.0 ASH COLLECTION DATA:Ash content in fuel = 14.21 %
Fuel consumption = 12560 kg/hrTotal Ash generation = 1785 kg/hr
Ash collection distribution :
Furnace Front Ash (25%) = 446 kg/hr
Bank ash hopper (5%) = 89 kg/hr
Economiser & APH ash hopper (10%) = 179 kg/hr
ESP Ash hoppers (60%) = 1071 kg/hr