As important as it is to ensure optimum efficiency of your running boiler to minimize fuel costs, so also is it to ensure safe operations of the boiler house. Being safe is the condition of being protected from any likelihood of danger, risk or injury. Safety is a team responsibility, and it is important that all members of the plant team take cognizance of, and adhere to, safety measures to ensure safe operation of the boiler house.
Safety of the boiler house is determined by various critical boiler parameters. It is therefore imperative that these parameters be continuously monitored to ensure safety at all times.
Feed water tank level – It should always be ensured that optimum feed water tank level is maintained. Low feed water levels could lead to feed pump failure, which in turn would lead to increased downtime as well as increased risk of tube explosion.
Boiler blowdown – Boiler blowdown should be optimized and maintained at about 3500 ppm. If periodic bottom blowdown is not taken, it could lead to tube rupture and thereby, increased downtime.
Supply oil/gas pressure – For oil and gas fired boilers it should be ensured that the supply pressure of the oil/gas should not exceed the safe operating value; otherwise there is risk of backfire.
Fuel spillage in furnace– Any spillage in of fuel in the furnace could lead to fire side explosion.
Steam pressure – High steam pressure boiler cutoff safety interlock should be available else it could lead to steam side explosion.
Combustion air flow – Correct ratio of fuel feed to the furnace and combustion air should be maintained; deficient air supply could lead to backfiring.
Boiler drum level – The boiler drum should always be maintained at appropriate levels; low drum level leads to increased risk of tube explosion.
Inadequate purging – Pre-purge and post-purge procedure should be followed at the time of start-up and shut-down. Inadequate purging could cause backfiring during boiler start-up.
Excess furnace pressure – Furnace draft pressure should be monitored and controlled; excess furnace draft pressure due to improper settings of FD and ID fan would lead to backfire.
Feedwater temperature – Temperature of feed water being supplied to the boiler should be maintained; supply of cold feed water can lead to thermal shocks resulting in tube rupture and increased downtime.
Feedwater contamination – A continuous check should be kept on the feed water quality; contamination could lead to tube corrosion and leakage.
Oil/gas leak detection - Detection mechanism should be in place to identify oil or gas leakage in the boiler house, in order to avoid fire hazards.
Bed temperature and bed height – continuous monitoring of bed temperature is required in the case of FBC boilers to avoid unstable combustion due to collapse of the bed.
Oil tank level – Incase of oil fired boilers, check should be kept on the oil tank level - low tank level could lead to dry run of the oil pump resulting in pump failure; high levels could cause overflow and increase the risk of a fire hazard.
A robust safety system needs to be put in place to ensure all relevant parameters as discussed above are continuously monitored. An automated system that can provide continuous monitoring of all critical boiler parameters, identify weak links and send out alerts to preset mobile numbers and e mail addresses. Data sent out from the system can be analysed and necessary corrective action taken to ensure any breach in safety is curbed before it becomes a threat.
The SafetyMax from Forbes Marshall is a comprehensive solution that helps plant personnel evaluate and enhance safety of the boiler house.
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