About Boiler Feed Water
Boiler feedwater is a necessary part of boiler operation. The feed water from the boiler is first placed into the hot water drum from an underground feed pump. Then in the hot water drum the feed water is turned to steam by the heat generated by the burning of oil. After the steam is successfully used it is dumped into the condenser. The condenser is made up of stainless-steel materials so as to withstand the high temperatures of the condenser coil.
After the boiler has reached the temperature at which it can safely begin to convert the feed water into steam, the sludge is removed. The solids that have settled to the bottom of the heating system are known as sludge. The primary reason for removing the sludge before it begins to boil is so it does not introduce any extra solids into the high-pressure boilers. This prevents the formation of “blower failures” where the boiler ends up shooting high steam through the tubes or induction towers because there are too much sludge and not enough high-pressure air.
The sludge must be removed in order to prevent the boiler from rusting. If the boiler does not contain enough of the chemical that contains oxygen, it will not corrode. The presence of oxygen in the presence of iron will cause the iron to react with oxygen in the water causing corrosion. It is important therefore to remove the sludge before the water begins to steam. However there are some boiler designs that contain two separate feed tubes that can be operated together to prevent corrosion.
A new design for the boiler feed water system includes the introduction of a secondary steam system to replace the solids that would normally be flushed out the bottom of the furnace. The secondary steam system also contains impurities that are designed to be recovered. These include lignite, bitumen and flue gas. The recovery of these impurities allows the system to operate at higher efficiencies than the traditional boiler feed water system.
A boiler requires an adequate thickness of lining so that the solids do not escape. Lining the bottom of the furnace is a poor solution because the solids will be flushed out the bottom and if the heating elements are installed too low, they will not be able to reach the boiler. They will therefore remain in the bottom of the boiler and if there is inadequate scale the boiler will be unable to achieve sufficient efficiency. A thick enough layer however is required so that the oils do not bubble and corrode.
Poor boiler feedwater efficiency occurs when too much oil is used to fuel the heating element and this causes the metal to form a scale. Too little oil and the metal will form a scale that blocks heat exchangers. This then reduces efficiency, but if heat exchangers are maintained they can prevent the scale from building up. The heat exchanger also absorbs energy and as it becomes ineffective it causes the boiler to lose efficiency. The heat exchanger should be cleaned and inspected to ensure that all solids are removed and that it functions properly.