A diffuser is a Round plate with a circular hole in the middle, and a number of radial grooves,which is placed in front of a jet atomizer of a boiler.
The function of diffuser or as normally called, swirler plate is to mix the air and fuel properly. There are radial cuts in the diffuser plate which will create a vortex flow of the air . Atomizer is directed into the middle hole of the diffuser. When the Combustion fan directs air into the diffuser, it creates a vortex flow. The atomizer nozzle directs the fuel into this vortex, which gets evenly mixed with the air. The flame stablity is greatly related to the cleanliness of the diffuser plate.
When the diffuser plate becomes dirty, mostly due to carbon and fuel particles sticking to it, the radial cuts in the plate are blocked. In this condition, the air supply to the boiler burner becomes low, and Boiler starts tripping at high loads. The air- fuel ratio cannot be maintained under a dirty diffuser condition. This further creates more carbon accumulation which may eventually fully block the diffuser swirler action, and failing the boiler even at low loads. This is a major reason why a boiler fires reasonably good under low load and trips under high loads, mainly above 70%. This is my personal experience onboard my vessel, where my boiler was tripping at 70%+ loads. Inspection of diffuser revealed considerable cabron accumulation. Once cleared boiler was firing normally under all loads.
To prevent the blockage of diffuser plate, always keep good fuel- air ratios. A small carbon accumulation can accelerate the spoiling of the plate.
Keep ur diffuser plates clean and have a happy boiler my sailor friends:) happy sailing.
The function of diffuser or as normally called, swirler plate is to mix the air and fuel properly. There are radial cuts in the diffuser plate which will create a vortex flow of the air . Atomizer is directed into the middle hole of the diffuser. When the Combustion fan directs air into the diffuser, it creates a vortex flow. The atomizer nozzle directs the fuel into this vortex, which gets evenly mixed with the air. The flame stablity is greatly related to the cleanliness of the diffuser plate.
When the diffuser plate becomes dirty, mostly due to carbon and fuel particles sticking to it, the radial cuts in the plate are blocked. In this condition, the air supply to the boiler burner becomes low, and Boiler starts tripping at high loads. The air- fuel ratio cannot be maintained under a dirty diffuser condition. This further creates more carbon accumulation which may eventually fully block the diffuser swirler action, and failing the boiler even at low loads. This is a major reason why a boiler fires reasonably good under low load and trips under high loads, mainly above 70%. This is my personal experience onboard my vessel, where my boiler was tripping at 70%+ loads. Inspection of diffuser revealed considerable cabron accumulation. Once cleared boiler was firing normally under all loads.
To prevent the blockage of diffuser plate, always keep good fuel- air ratios. A small carbon accumulation can accelerate the spoiling of the plate.
Keep ur diffuser plates clean and have a happy boiler my sailor friends:) happy sailing.
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