On the circulation of water in steam boilers: Address before the American railway master mechanics' association at their meeting in Philadelphia, June, 1876
✍ Scribed by Robert Briggs
- Publisher
- Elsevier Science
- Year
- 1876
- Tongue
- English
- Weight
- 665 KB
- Volume
- 102
- Category
- Article
- ISSN
- 0016-0032
No coin nor oath required. For personal study only.
✦ Synopsis
GENTLEMEN :--I am much gratified by the honor conferred upon me in being requested to address you upon the subject of the phenomena attending the ebullition of water, and with the risk that I may be reciting facts well known to all, and certainty that what I shall say will be merely elementary, I venture to quote a portion of a lecture delivered by me before the Franklin Institute~ trusting that a new view of old facts may not be out of place.
The three forms of matter--solid, liquid and gaseous--are incident to some definite quantity of heat which accompanies each form, which is known as the latent heat, and varies in amount for the different substances. For water, which is the substance under consideration at this time, the latent heat added to and absorbed in the change of form from ice at 32 ° to water at the same temperature, is 142°.65 (Person), and in the change of form from water to steam of 32 ° is 1,092 ° (Regnault). But the sensible temperature of a liquid at which it will vaporize is found to vary with the pressure (or tension) of the vapor above it, and the tension of steam at 32 ° is only 0"085 lbs. per square inch, while the pressure of the atmosphere is 14'7 lbs. per square inch. Ebullition or free boiling of water does not take place under atmospheric pressure until the water is heated up to 212 °, at which point the tension of steam is equal to the usual atmospheric pressure of 14'7 lbs. per square inch, and the latent heat of change of form from water at 212 ° to steam at the same temperature, is 966 ° (Regnault).
The other properties of water, as regards heat, with which we have to do in considering the circulation in a boiler, are its expan-