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old heavy iron and machine tool photo's

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PTsideshow:
I was sent this link, and for any body into machines and old heavy iron, this is for you.
engines and machine tools photo's in the old days

Have lots of free time

Bernd:
Glenn,

Nice archive of old pictures, all 164 of them. Amazing what was done before elcetronics and computers came along. :headbang:

Bernd

dsquire:
Glen

Thanks for posting the link. I went and looked at all 164 and a bunch of them twice. I found one description (that repeats several times) which I think is in error.

Description: The Mesta Machine Company produced various types of engines for its customers. These engines included gas and steam powered engines for use with blast furnaces, una-flow or direct-flow engines for driving roll mills, and reversing and Corliss engines. These engines were designed to withstand steam pressures up to 180 pounds and superheat up to 75 degrees Fahrenheit. Mesta designed the Corliss Engine for use in rolling mills, power engines, blowing engines, air and gas compressors, pumping engines, and vacuum pumps.

"superheat up to 75 degrees Fahrenheit" I didn't think that 75 degrees Fahrenheit was that hot, heck I like my shower hotter than that. I'm not doing this to nit pick but if it is wrong I figure that they would like to be giving out the correct information. If anyone can confirm what this should be I will try and get a hold of the Library and Archives Division, Senator John Heinz History Center and advise them of the error.

Cheers  :beer:

Don

Bluechip:
Don

I think superheat refers to an increase in temp. above the normal steam temp. taking into account the boiling point of water is higher as the pressure increases.

ie. say a boiler pressure of 100 psig  ( 115-ish psia ), the saturated steam will be at 338F. so 75F of superheat the steam temp will be some 413F.

Dave BC

Sorry Dave, I thought I hit quote and started to type before I realized that I had hit modify instead.

The dangers of Moderators not paying attention! :bugeye:

PTsideshow:
I'm sure there are a couple more that I noticed just the general descriptions are probably from some librarian/photo scanning person. that doesn't have a clue or was trying to interpret the writing on the back of the photo's.
They used lower super heat temperatures, then a lot of equipment did. Having not had to deal with super heat for the last 25 years of my boiler /engineer operating career. I can say that I would have to dig through the books to get the numbers of what and the temp points. It wasn't a fun subject the first time around when I wrote for my license. 34 years ago.

Knowing how small museums work, they used the same description when they didn't have one or a clue  :bugeye:

Ok ya got me! I think this will give the basic answer. In the US back in the day the max operating superheat temps were 600'F other than for some composite tandem type engines at the Ford plant here in Detroit were the steam temperature was 700'F

Well here is a brief idea:
Because the steam is dry, it behaves more like a gas, no condensation as the engine absorbs heat from the steam. The economy increase is based on the fact that if the superheat is high enough not only to supply the heat absorbed by the cylinder walls but also the heat equivalent of the work done during the expansion, then the steam will be dry and saturated at release.

This is the condition of maximum efficiency in a single cylinder.

A superheat of 250'F to 350'F at admission is necessary to in sure the steam is dry at release in the average single cylinder engine.

Another advantage for piston engine work, A moderate amount of superheat produce a large increase volume, the pressure remaining constant, and diminishes the weight of the steam per stroke for a given amount of work.
And it has a lower thermal conductivity, less heat is absorbed by the cylinder walls.

Steam Power Plant Engineering, By G F Gebhartdt, 1922 edition

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