Exhaust Gas Boiler Fire causes and actions to be taken in such scenario are discussed in this article. If proper precaution and maintenance is done, such a scenario can be avoided easily. It has happened that fire have become so intense that it has lead to melting of the whole boiler. So we will divide this article in four sections
- -Indications of fire
- -Reasons of exhaust gas boiler fire
- -Action to be taken in case of exhaust gas boiler fire
- -How to avoid such fire from happening
Let’s pick up the first part which contains the reasons which leads to such event.
Reasons of Exhaust Gas Boiler Fire
Following are the reasons but not limited to the ones mentioned below:
- Excessive Soot Accumulation Inside the Boiler
- Faulty Fuel Injection System, leading to incomplete combustion products reaching to the boiler
Indications of Boiler Fire
- Sudden and Sharp increase in Temperature of exhaust gas boiler
- Sudden increase in pressure of steam in the drum and also water level will change suddenly.
- Sparks from the funnel
- Erratic operation of turbocharger.
Actions to Be Take In Case of Uptake Fire
Following action to be taken in case of fire inside the boiler
- Check if the sensor or gauge is correct
- If above condition is correct call bridge and tell them about this condition.
- Slow Down the engine, preferably at dead slow ahead.
- Call for help from other engine officers.
- Keep the water circulating running; it will be good idea to run both the pumps.
- Keep an eye on the level of water in the drum. A rapid decrease in the water level will indicate tube leakage
- Check the exhaust from the funnel for color from time to time. If it is too white, it means there is a water leak. If too much Sparks are coming, it means there bigger fire.
If the temperatures drop and smoke from the tunnel is returning to normal, that means fire is extinguished. In that case a good spot blow is needed. And then engine can be speed up slowly. Check the temperature of each unit.
If the fire keeps on increasing, then follow the process below.
8) If bypass for the exhaust gas boiler is given, then open it and close the main exhaust damper.
9) If not, then stop the main engine completely and direct crew for preparing for boundary cooling, just in case fire gets worse.
10) Keep an eye on the level of water drums and also the temperatures across the boiler.
11) If the water level is dropping fast and temperature across the boiler are rising, that means it is going for a hydrogen fire.
12) Stop the boiler water circulation pumps and close the valves.
13) Check the exhaust for kind of smoke coming.
14) Boundary cooling can be adopted to cool the fire.
If the hydrogen fire is not controlled, then at higher temperature, the fire will turn itself to metal fire and it is impossible to control such fire. Only thing which can be done in that case is to do boundary cooling.
Such reaction takes place at higher temperature:
2H20 → 2H2 + O2
H20 + C → CO + H2
2Fe +O2→ 2FeO + Heat
Fe+ H20→ FeO + H2 +Heat
How to prevent exhaust gas boiler uptake fires
Following practices if followed will surely going to help in prevention of such event taking place:
1) Keep all the fuel injectors in proper working condition. Faulty injectors to be replaced as soon as possible
2) Regularly soot blow the exhaust boiler.
Note: Soot blow should always be done at higher load for having maximum flow and all the soot is carried away by the exhaust gases.
3) Regular inspection of exhaust gas boiler especially the soot blowers to be carried out.
4) Cold cracking to be carried out on regular basis and after cold cracking, a good soot is must.