PECM Issue 31 2018 | Page 54

EFFICIENT PRODUCTION OF STEAM VIA PROPER BOILER OPERATION oilers are industrial equipment used for the production of steam. There are various types of boilers in industrial use, from the small scale process user to the large scale combined heating and electric power producer. They are classified as plain double shell, fire tube, and water tube boilers in terms of their construction and as low pressure, medium pressure, high pressure and very high pressure boilers in terms of the pressure. The water tube boiler is large scale. Most large scale industries use water tube boilers. Boilers being high-pressure vessel have to be designed and fabricated to a high standard of safety. They are made up of bank of tubes, inside which water circulates, connected to one or more headers and drums. B The variety of types in the steam generation field has led to the classification in terms or their characteristics. A possible classification criterion is the pressure and temperature, however the distinction is not very precise but can be adapted for convenience. Boiler can be defined as a process equipment 54 PECM Issue 31 that is used to generate steam by heating de-mineralized water until it is converted to steam of varying pressures. B oiler O perations • How to prepare the boiler for commissioning • How to operate the boiler • About boiler servicing and maintenance T o prepare B oiler for C ommissioning Process operators need to ensure that; 1. The water tubes are leak free. 2. The water chamber is leak free and pressure tight. 3. The steam tubes are leak free. 4. The steam chamber is leak free and pressure tight. 5. The combustion chambers is lined with correct refractory materials. 6. The flue gas chamber is lined with correct refractory material. 7. The combustion chamber, gas path down to the stack is unblock and Ok. 8. The flue gas chamber and its path to the stack is also clear. 9. The force draught fans is functioning well 10. The feed water (well treated and de- ionized) pump is functioning alright and its pressure slightly above the pressure of its surge drum. 11. The economizer and exchanger are ready, and in good condition. 12. The down-comers and riser are leak free and pressure tight. 13. The safety valves, vents and drains are in good working condition. 14. All instruments (level, pressure gauge, controllers and valves etc) are all ok. 15. The cyclones in the steam drum is functional. 16. The scrubbers are in good condition. T o O perate a B oiler 1. Start water circulation. 2. Check for leakages. 3. Pressure test. 4. Start heating up. 5. Monitor pressure rise. 6. Check for leaking tubes as temperature and pressure rise. 7. Continue heating up. 8. Stabilize the operating condition.