one employed at Minnesota State is a tray-type (shown in the picture). The tray-type consists of a series of internal cascading trays in which feed water is directed. Steam bled off from the steam drum is run through a regulator to 10 psig and is allowed to rise over the trays. When it comes in contact with the feed water a "scrubbing" action occurs which causes the non-condensable gases to be driven out of the water and released. Non-condensable gases then vent to the atmosphere. The most important purpose of the deaerator is the removal of dissolved gases. It also functions as a feed water heater, feed water storage, and for feed water surge prevention. Feed water surge is when there is a large and sudden increase in feed water flow to the boiler.
Blowdown is a common procedure for a boiler to control the contaminants in the boiling water. Two types of blowdown exist, manual and continuous. For a continuous blow down, a calibrated valve continuously takes water from the top of the boiling surface in the steam drum. In this case, many of the contaminants consist of oils floating on top of the water. Once a shift, the collected blowdown water is cooled in a tank and returned to the city’s waste water. To replace the water removed from the system, conditioned city water is added to the holding tank where the condensate is collected after returning from campus.
An economizer is employed to utilize the waste heat generated from the combustion process to
improve overall efficiency in the boiler(shown in picture). 
Flue gas exiting the combustion chamber is still very hot and can be used as a pre-heater for the feed water. The economizer used for these boilers is a horizontal counter current shell and tube heat exchanger. Feedwater enters finned tubes while hot flue gases pass over the outside. This allows for the recovery of energy which would otherwise be wasted.
When combustion occurs, the flue gas contains numerous compounds. Some of these compounds will collect on surfaces within the furnace and start to buildup (the inside of the furnace is shown in the picture). Soon the buildup will start to affect the overall performance of the boiler by obstructing the heat transfer. 
To cure this problem, two sootblowers are installed inside the furnace. One is a rotating sootblower, while the other is a non-rotating sootblower. Both the rotating and non-rotating sootblower will extract steam from the steam drum and spray the internal components of the boiler. The rotating blower is positioned on a
