ECONOMY
IN
THE USE OF STEAM:
A STATEMENT OF THE PRINCIPLES ON WHICH A SAVING
OF STEAM CAN BEST BE EFFECTED. <...>
ECONOMY IN THE USE OF STEAM. <...> It is an attempt
to state the principles laid down by theoretical writers, — Clausius, Rankine, and others, who are better
known in the class-room than in the office, — in such a form as to be useful to practical Engineers; to
test by these principles the modes of working which have been found most advantageous in practice;
and to offer here and there some new suggestions. <...> Mathematics have been dispensed with as far as
possible; and where they could not be altogether avoided, a smaller type has been used in order that the
reader who wishes to pass over the mathematical parts may do so conveniently. <...> The principal
conclusions have been printed in italics to attract the attention of any who have not time to read the
whole. <...> The later chapters will therefore have the most interest for Engineers, but they
will be more readily followed if the early ones are not entirely passed over.
2
ECONOMY IN THE USE OF STEAM. <...> Before entering upon the subject of the action of steam in the cylinder of an engine, a few
preliminary observations will be necessary to guard against mistakes which sometimes arise with
reference to the scales of measurement of pressures, temperatures, &c.
Absolute Pressure. — The usual mode of denoting pressure of steam, namely, in pounds above
the atmospheric pressure, is simple and convenient for most purposes relating to the boiler, but leads to
misconception when applied to steam in the cylinder of an engine. <...> Water evaporated in the open air is
said, according to this notation, to be transformed into steam of zero pressure, instead of steam of 14•7
Ibs. pressure per square inch, which pressure counterbalances that of the atmosphere. <...> If such steam is
used in a condensing engine, the effect is said to be due to vacuum, which is still regarded by some
people as a separate force unconnected with the steam, and in fact operating on the other side of the
piston. <...> When steam of higher pressure is used, it is customary <...>
Economy_in_the_use_of_steam.pdf
ECONOMY
IN
THE USE OF STEAM:
A STATEMENT OF THE PRINCIPLES ON WHICH A SAVING
OF STEAM CAN BEST BE EFFECTED.
BY
FRANK SALTER, B.Sc.,
LATE WHITWORTH SCHOLAR.
LONDON:
E. & F. N. SPON, 48, CHARING CROSS.
NEW YORK:
446, BROOME STREET.
1874.
Стр.1
ECONOMY IN THE USE OF STEAM.
CONTENTS
PREFACE. ................................................................................................................................................................ 1
CHAPTER I. INTRODUCTION.............................................................................................................................. 3
CHAPTER II. THEORETICAL INDICATOR DIAGRAM. ................................................................................... 6
CHAPTER III. EFFECT OF COOLING DURING EXPANSION...................................................................... 10
CHAPTER IV. THE STEAM JACKET. ................................................................................................................ 17
CHAPTER V. SUPERHEATING.......................................................................................................................... 19
CHAPTER VI. THROTTLING AND WIRE-DRAWING..................................................................................... 21
CHAPTER VII. INTERMEDIATE EXPANSION IN COMPOUND ENGINES................................................ 23
CHAPTER VIII. SIZE OF RECEIVER. ............................................................................................................... 30
CHAPTER IX. EQUALIZATION OF HORSE-POWERS. .................................................................................. 32
CHAPTER X. PASSAGES AND CLEARANCE................................................................................................... 34
CHAPTER XI. CONCLUSIONS. .......................................................................................................................... 38
Стр.2
ECONOMY IN THE USE OF STEAM.
PREFACE.
This little book deals with the use of steam as distinguished from its production. It is an attempt
to state the principles laid down by theoretical writers, — Clausius, Rankine, and others, who are better
known in the class-room than in the office, — in such a form as to be useful to practical Engineers; to
test by these principles the modes of working which have been found most advantageous in practice;
and to offer here and there some new suggestions. Mathematics have been dispensed with as far as
possible; and where they could not be altogether avoided, a smaller type has been used in order that the
reader who wishes to pass over the mathematical parts may do so conveniently. The principal
conclusions have been printed in italics to attract the attention of any who have not time to read the
whole. The earlier chapters refer especially to the theory of the working of steam, and the others to the
application of the theory. The later chapters will therefore have the most interest for Engineers, but they
will be more readily followed if the early ones are not entirely passed over.
2
Стр.3