1. Design Features of the Enthalpy Circulating Fluidized Bed (CFB) Boiler:

• Fuel feeding system: a belt conveyor combined with a fully automatic flexible metering screw feeder delivers fuel from the feed hopper (or storage silo) into the furnace in proportion to the boiler load.
• Furnace (combustion chamber): a sealed design with a combustion belt of wear-resistant refractory castable cast directly onto the water-wall tubes. This keeps the combustion zone at the optimum temperature and lasts many times longer than a furnace lined with refractory bricks.
• Boiler body: all heat-absorbing surfaces are made of 100% ASTM-standard seamless tubes rated for high pressure and high temperature.
• Steam drum: made of special heat-resistant steel and located at the highest point of the boiler to maximize natural water circulation, steam–water separation and removal of surface scum and sludge. The drum shell is completely isolated from the flue gas path to ensure the highest operational safety factor.
• Cyclone separation and recirculation system returns unburned fuel particles to the furnace. It is intelligently designed and combined with an optimized air distribution system to ensure complete combustion of the fuel.
• Air supply system includes primary and secondary air fans, loop-seal (return) air, fuel-spreading air, an air preheater, and air ducts arranged and regulated for complete fuel burnout.
• Control system: fuel feeding, combustion air, feedwater, ash discharge, bottom blowdown and surface blowdown are fully automated.
• Protection system: pressure and water-level interlocks, combined with safety valves and blowdown valves, are designed to ensure maximum safety for personnel and equipment.
• Dust collection system: multi-stage dust collectors ensure that flue gas emissions always meet the permitted environmental limits.

2. Operating Principle of the Circulating Fluidized Bed Boiler:

     Fuel is delivered into the boiler furnace by the fuel feeding system. In the furnace, fresh fuel absorbs heat from the fluidized bed, which consists of burning fuel and inert bed material, and is quickly raised to its ignition temperature. The burning fuel releases heat and produces combustion products: ash, slag and flue gas.

     The heat released by combustion is transferred to the furnace water walls and to the tube banks in the boiler body. The water inside the water-wall tubes and tube banks absorbs this heat, turns into steam, raises the pressure and rises to the steam drum. In the steam drum, steam is separated from the water and flows into the main steam line to the point of use.

     The flue gas, fly ash and part of the unburned fuel leave the furnace and enter the cyclone separator. There, unburned fuel particles are separated from the gas stream and returned to the furnace for complete combustion. After leaving the cyclone separator, the flue gas passes through the economizer and the air preheater to recover as much of the remaining heat as possible. It then enters the dust collectors, where pollutants are removed from the gas stream.  Finally, the induced draft (ID) fan discharges the flue gas through the stack into the atmosphere.

3. Outstanding Advantages of the Enthalpy Circulating Fluidized Bed Boiler:

• Highly durable, long service life and safe, thanks to genuine materials and design and fabrication in strict compliance with the highest procedures and standards.
• High efficiency, as the fluidized bed combustion technology is optimized for each fuel type and its corresponding air distribution system, combined with maximum flue gas heat recovery to preheat feedwater and combustion air. 
• Fully automated control and monitoring system that further improves safety and stability while reducing operating labor.
• Environmentally friendly, with advanced process control and state-of-the-art multi-stage flue gas treatment equipment.
• Convenient, compact, well-ventilated and space-saving installation layout that complies with industrial codes and, above all, is custom-designed to fit the specific requirements of each plant.

​Enthalpy is committed to designing and manufacturing circulating fluidized bed boilers that deliver the best economic performance and the highest level of safety to our customers.

1. Boiler type: circulating fluidized bed boiler, water tube combination, one steam drum, natural convection.

2. Fuel used: Fuel is coal bran of Vietnam, Indo, types of biomass like sawdust, chopped chips, tablets, rice husks ...

3. Size of fuel: from 0 - 20mm for coal bran.

4. Power use: 3 phase 380V, 50Hz

5. Working mode: Two options are available: Automatic - Manual in fuel supply, wind supply, water supply, and slag discharge.

6. Manufacturing standard: TCVN 7704 - 2007; TCVN 6413 - 1998; TCVN 8366 - 2010; or according to ASME standard, ...

7. Environmental standards: The noise is less than 85dB, 1m away from the furnace; The exhaust gas is in accordance with QCVN 19: 2009 / BTNMT standard.

8. Main technical data sheet: