High-pressure Steam Locomotive - The Schmidt System

The Schmidt System

One way to avoid corrosion and scale problems at high pressure is to use distilled water, as is done in power stations. In fact you need to go further: dissolved gases such as oxygen and carbon dioxide also cause corrosion at high temperatures and pressures, and must be kept out. Most locomotives did not lug a condenser around with them, so there was no source of pure feed water. One solution was the Schmidt system; this used a sealed ultra-high-pressure circuit that simply transferred heat to a high-pressure circuit, by means of heating coils inside a high-pressure boiler. If this latter is fed with ordinary water, scale may form on the outside of the heating coils, but it cannot cause overheating, as the ultra-HP tubes are quite capable of withstanding their internal steam temperature, though not the firebox flame temperature.

The sealed ultra-high-pressure circuit ran at between 1,200 and 1,600 psi (8.27 and 11.03 MPa), depending on the rate of firing. The HP boiler worked at approx 850 psi (5.86 MPa), and the low-pressure boiler at 200 to 250 psi (1.38 to 1.72 MPa). The UHP and HP boilers were of a water tube design, while the LP boiler was a fire tube boiler typical for steam locomotives. The LP cylinders were driven with a mixture of the HP cylinder exhaust and the LP boiler output. Both HP and LP boilers had superheaters.

The French PL241P, the German H17-206 and the British LMS 6399 Fury all used the Schmidt system, and were of basically similar design. The New York Central HS-1a and the Canadian 8000 also used the Schmidt system but were a size larger altogether- the 8000 weighed more than twice the Fury.

Read more about this topic:  High-pressure Steam Locomotive

Other articles related to "schmidt":

Barack Obama Citizenship Conspiracy Theories - Campaigners and Proponents - Political Candidates and Elected Officials - Jean Schmidt
5, 2009, Republican congresswoman Jean Schmidt replied to a woman who commented that Obama was ineligible for the Presidency, "I agree with you ... But the courts don't." Schmidt's office subsequently responded that a video clip of this comment was "taken out of context", and reiterated that her stated position is that Obama is a citizen ... statement was issued in response to a July 28, 2009, YouTube video in which Schmidt was seen running away from Mike Stark when he asked whether or not she had any ...
The Vicky Bliss Mysteries - Characters
... She specializes in medieval art and works for Schmidt at the National Museum in Munich ... Schmidt Herr Professor Anton Z ... Schmidt is Vicky's round, jovial boss ...
Martin Johann Schmidt
... Martin Johann Schmidt, called Kremser Schmidt or Kremserschmidt, (September 25, 1718 at Grafenwörth, lower Austria - June 28, 1801 at Stein/Danube (now belonging to Krems an ... A son of the sculptor Johannes Schmidt and a pupil of Gottlieb Starmayr, he spent most of his life at Stein, where he mostly worked in the numerous churches and ... replaced by a renewed concentration on religious topics during the very last years of Schmidt's life ...
Adding Machine (musical) - Background
... was able to attract composer Joshua Schmidt to the project Schmidt composed the music, and wrote the libretto and book together with Loewith ... Schmidt met Loewith because he was the artistic director of company at Next Theater ... Schmidt explained why his show had such a small band "At Next Theater, we had a 15-by-5 space for the orchestra — a shoebox with a very low ceiling ...

Famous quotes containing the word system:

    You and I ... are convinced of the fact that if our Government in Washington and in a majority of the States should revert to the control of those who frankly put property ahead of human beings instead of working for human beings under a system of government which recognizes property, the nation as a whole would again be in a bad situation.
    Franklin D. Roosevelt (1882–1945)