Boiler Efficiency and Combustion | Spirax Sarco
01/01/1996 · The root of the flame will move away from the bumer throat and become unstable due to the low specific heat of the flame. At higher firing rates the fuel and air mixture can become slightly compressed at the back of the furnace and burn off the back wall. Time, in this case, relates to velocity and thus reduces specific heat per unit of flame length.
Pressure from legislation regarding pollution, and from boiler users regarding economy, plus the power of the microchip have considerably advanced the design of both boiler combustion chambers and burners. Modern boilers with the latest burners may have: Re-circulated flue gases to ensure optimum combustion, with minimum excess air.
Unstable operation of the boiler may be caused by quality of fuel, with cold flow properties being one of the reasons for repetitive trips. One such example being the explosion of the Auxiliary Boiler on board of Container Vessel MANHATTAN BRIDGE (MIAB Safety Bulletin, Japan Transport Safety Board Marine Accident Investigation Report)
Poor combustion and/or defective burners can result in deposits of unburned fuel in the furnace. • Unstable fuel control systems can cause fuel pressure spikes, flow surges and poor combustion with the attendant risks of explosive ignition in the furnace. • Incorrect fuel gas flow control valve settings can introduce quantities of fuel
When the combustion began to be unstable, the flame started to pulsate and the CO-level to increase. The amount of pyrolysis oil (PO) was then reduced until stable conditions appeared again. Over the two days, the boiler was operating with bio-oil for approximately six
However, incidents related to fuel systems and combustion equipment still occur far too frequently. It seems we have hit a plateau with fuel and combustion equipment safety. Maybe its because of aging infrastructure or a lack of enforcement of existing codes and standards.