Bulging of boiler’s furnace shell at a Hotel, Bandar Baru Bangi .

Rujukan

DOSH

The purpose of this safety alert is to raise awareness among public, competent personnel, and workers who are directly or indirectly involved with the use, operation and maintenance of steam boiler - regarding the accident involving a steam boiler which is used by a hotel around Bandar Baru Bangi. The root causes of this accident can be possibly due to the combination of one or more of these factors: low water, mis-alignment of furnace nozzle, the formation of scales on the furnace wall on the water side and operation which does not comply to DOSH’s safety requirements.

 

It is important for employer or safety and health officer to make good observation regarding the responsibilities of the competent person who is in charge for operating the steam boiler to avoid any bad occurrences.

The boilerman should ensure the safe use and operation of the steam boiler at all times during his charge in order to prevent the accident like this from occurring.

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Figure 1: The bulging defect on the boiler furnace [looking from the fire side]

Preventive measures

1.The accident like this could happen if the feed-water is not properly treated and this may cause formation of scales on the water side. So it is important, for person in charge of the steam boiler to follow any instructions issued by the employer or any firm that undertakes the feed-water treatment.

2.Unfortunate event like this, is normally due to the localised heating phenomenom, where the heat transfer from the furnace shell to the water side is concentrated only in certain area of the furnace shell. The possible reasons for this phenomenom:

i.there is no medium that can absorb the heat transfer from furnace shell (especially during the low water level condition;

ii.the formation of layer of scales on the waterside which blocks direct heat transer from furnace to water side and causes localised heating; and

iii.mis-aligntment at the nozzle burner which can cause the hot flue gas to converge and concentrate only at certain point or area of the furnace shell.

Therefore, it is important uphold on safe operating procedure, conduct regular monitoring and to undertake preventive maintenance on steam boiler.

3.The boilerman who is in charge for the operation of the steam boiler should inspect the boiler safety devices like water gauges, mobrey controllers, blowdown valve, burner cut-off, safety valves, feedwater pump, and pressure cut-off switch during the operation of steam boiler and report to their top management of any problem arising.

Figure 1: Low water problem can cause overheating and bulging defect on the furnace shell

Figure 2: Mis-alignment of burner attachment can cause localised overheating

Figure 3: Formation of layer of scales on the furnace wall at the water side can cause overheating and bulging defect on the furnace shell.