Whether it is -10°F or 95°F
outside, heating of air or water is always required somewhere on the MSU campus. Campus building heating and water heating is all done using
steam. The facilities plant located 
at the northwest corner of campus houses
four boilers that provide all of the heating required on campus. The first two
boilers were installed in 1959, with the third in 1968, and the original fourth
boiler in 1972. In 2004 the fourth boiler was replaced with the one in
operation today. Watch the video below to see what the boiler room looks like
from the inside.
Water Tube Boiler Walkthrough Video
Each
of the four boilers is a "D" type water tube boiler. Each water tube boiler includes
two drums connected by steam generating tubes, producing steam at 150 psig. 
A
boiler is
rated by how many pounds of steam it produces per hour. The
first two boilers are rated for 35,000 lb/hr, the third is rated for 75,000
lb/hr, and the fourth boiler was originally rated for up to 90,000 lb/hr. An
elevated view of the boiler room is shown in the picture at above.
The boilers at MSU produce saturated steam, but many boilers are made to produce superheated steam (implying the temperature is above the boiling point).
Picture of a Superheating Drum Type Boiler
If you think the paperwork you have to fill out as a student is cumbersome,
consider this. The permit acquired by Minnesota State will allow for
steam production up to a total of 100 MBTUH. A MBTUH is an abbreviation for one
million BTUs/hr. If the fourth boiler is to run at full capacity the campus
would exceed its permit limit. However, running the boiler at only 80,000 lb/hr
satisfies the campus demand and the permit requirements. Therefore, the fourth
boiler was re-rated. De-rating the boiler by physically changing the spud
burners (a device used to bring in fuel to the furnace) was an easier solution than applying for a new permit from the state!
The basic purpose of a boiler is to turn water into steam, in this case
saturated steam. This operation sounds relatively simple but is actually more
complicated. Other components and 
processes such as the deaerator and
economizer are necessary to help
the overall operation run more efficiently. The boilers utilized on campus are of the stack drum
type,
