--- In STMFC@..., "Clark" <cepropst@...> wrote:

We were talking the other day about power plants at medium sized industries. Asking ourselves, but not knowing the answers to the questions; How many car loads of coal would the average boiler power generating system use? And what's the percentage ratio of coal to clinker or cinders?

Clark,

The discussion has been mainly focused on the cinders, but I want to take a stab at the first part. 2 different data points give similar answers. Pennsylvania Power and Light (PP&L) built a coal fired plant at Holtwood PA, site of a hydro generating plant on the lower Susquehanna river. That plant was designed as a "backup plant" to provide additional power at low water levels. It received up to 50 x 50 ton car loads per day of dredged river bottom coal dust (from the upstream breakers). I also know of a small coal fired power plant in Rochester NY that some time in the future (beyond our 1960 cutoff) would get 50 x 100 ton hoppers of coal 2-3 times per week.

So, in both cases, I make that to be 10,000-15,000 tons of coal per week. It is important to note though that in both cases, coal was also stockpiled against the threat of mine strikes, so the actual consumption was somewhat lower (but still enough to justify some serious switching!).

Regards
Bruce Smith
Auburn, AL

Thanks guys, very interesting.

I guess I do need to clarify what type of industry I'm talking about. I my case a meat packing plant. There were hundreds of similar sized companies that made their own power during the time of this list.

Clark Propst

--- In STMFC@..., "rockroll50401" <cepropst@...> wrote:

Thanks guys, very interesting.

I guess I do need to clarify what type of industry I'm talking about. I my case a meat packing plant. There were hundreds of similar sized companies that made their own power during the time of this list.

Clark Propst

Clark, the Ahnapee & Western Railway that I model had an evaporated milk plant on its line at Sturgeon Bay, Wisc, which received coal in carloads for a steam/light plant. Using the waybill records that I have, the plant received a twin hopper of coal every third day, or so (about 2 cars/week). This plant was steam sterilizing cans, homoginizing milk, as well as powering the plants lights, so you would have to take that into account. Their output was about 3 cars of canned evaporated milk per day...5 days per week.

The coal was put on the ground in piles by small wheeled under-car conveyor, then moved by that same conveyor into trucks for a 300' move to the boilerhouse.

Andy L.
South Bend, IN

I imagine there are a number of Google Books entries about the operation of coal-fired boilers and generators froom the steam era. Certainly these would give examples of production in pounds of steam or kilowatts / ton of coal. Probably even the amount of cinders to expect . . .

KL

If you really want to do an accurate job of determining the number of cars of coal needed to generate power, you can look at how that is done on my Chemical Engineering 357 class web site at The University of Texas at Austin under part III lecture notes.

http://www.utexas.edu/research/ceer/che357/PDF/Lectures/intro_air_pollution.pdf
 
These the notes I use from my lectures, so there are many comments provided in class.  This course is designed for senior chemical engineers, so there are many assumptions made about the knowledge base for the students.  In calculating the amount of cinders, you can calculate the amount of particulate matter that is emitted througth the stack, calculate the amount of ash in the coal, and the difference will be the amount of bottom ash (cinders).  The example illustrates the process with a typical coal.  The BTU content and ash content for coal vary significantly for coal mined in various parts of the country.  To obtain more examples of various coals and lignites you can look at the coals I use for project 3 that my students have to complete.  These are for coals mostly in use today.
 
http://www.utexas.edu/research/ceer/che357/PDF/Projects/Project3/ChE%20357%202009-project%203%20fuels%20and%20stacks.pdf
 
Most likely a lot more than any of you want, but just to let you know there is a way to determine the amount of coal needed to produce a given amount of power.  Also needed is the efficienty of the power plant.  Coal plants typically have a maximum efficiency of 41%, with older plants being much less than that.
 
Cyril Durrenberger