Connection with Compound Steam Engines.
Year: 1887

page_text: Date of Application, 28th Apr., 1887
Complete Left, 26th Jan., 1888
Complete Accepted, 2nd Mar., 1888
Connection with Compound Steam Engines.
We, JAMES WEIR, and GEORGE WEIR, both of 2 Commerce Street, Glasgow, in the
County of Lanark, North Britain, Engineers, do hereby declare the nature of this
Invention to be as follows, that is to say :--
Our said Invention has for its object to economise fuel by improvements relating to
the heating of the feed water of boilers supplying steam to compound engines working
with two or more stages of expansion and comprises arrangements whereby the feed
water is heated by steam which has operated to a certain extent in the engine but
which is applied for that purpose before the steam is finally exhausted.
The improvements are applicable more especially to what are known as triple
expansion and quadruple-expansion engines; whilst with more stages of expansion the
saving will be greater.
It may also be with advantage applied in conjunction with improvements described
in specifications of various Patents obtained by the present applicants namely: those
numbered 1936 of 1871, 5012 of 1876, 1568 of 1878, 4351 of 1879, 335 of 1880,
4379 of 1880, and 6007 of 1887.
In our previous Patents the whole heating of the feed water was done before it passed
through the feed pump that forced it into the boiler, but by the present Invention
the full boiler pressure is put on the water before it gets heated to the higher
temperatures.
In carrying out the Invention according to one modification when applied to triple
expansion engines the feed water is taken from the hotwell or feed tank by pumps wrought
by the main engine, or by separate pumps and is subjected to the pressure necessary
to put
into the boiler. After leaving the pump it is made to pass through a heat
exchanging apparatus or heater, constructed of metal tubes or plates, the feed water
being on one side; and on the other steam taken from the engine, after having
performed its work in the first and second cylinders. The feed water then passes into
a second similar heat exchanging vessel, or apparatus and steam that has only
performed work in the first cylinder is used to complete the heating, the water then
passing to the boiler in the usual way.

page_text: The water of condensation formed from the steam at the highest pressure may
either be led in along with the steam of the lower pressure, or it may be drawn
off and led into the hotwell or tank to utilise the remaining heat as the heat
exchanging apparatus only utilises the latent heat of the steam. The water of
condensation from the lowest pressure is put into the hotwell in the same manner if
the pressure is above the atmosphere; but in a great number of cases the pressure is
below the atmosphere; and when it is so the water is led to the condenser, but it will
be advisable to cool it down with the feed water before allowing it to escape into the
condenser. The air that may accumulate in the heat exchanging apparatus must be
removed either along with the water or separately. When the pressures are above the
atmosphere it may be simply allowed to escape, but when below the atmosphere it
must be led to the condenser or a pump.
The heaters can either be separate or be combined in one vessel with soparate
chambers for the steam of the different pressures.
This system of heating the feed water may be used in combination with our
former arrangements; the old system with direct contact between steam and water being
adopted for the lowest stage; and the new system with conduction through metal
being adopted for the higher temperatures.
EDMUND HUNT,
Per pro David Ferguson,
Applicants' Agent.

page_text: Improvements relating to the UT Է ԵԵԱ
Connection with Compound Steam Engines.
We, JAMES WEIR, and GEORGE WEIR, both of 2 Commerce Street, Glasgow, in the
County of Lanark, North Britain, Engineers, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement, that is to say:-
Our said Invention has for its object to economise fuel by improvements relatingto
the heating of the feed water of boilers supplying steam to compound engines working
with two or more stages of expansion; and comprises arrangements whereby the feed
water is heated by steam which has operated to a certain extent in the engines but
which is applied for the purpose before the steam is finally exhausted.
Our present improvements are applicable more especially to what are known as
triple-expansion, and quadruple-expansion engines; whilst with more stages of
expansion the saving will be greater. They may also be with advantage applied in
conjunction with improvements described in the specifications of various patents
obtained by us, namely those numbered 1936 of 1871, 5012 of 1876, 1568 of 1878,
4351 of 1879, 335 of 1880, 4379 of 1880, and 6007 of 1887. In some of our earlier
patents the whole heating of the feed water was done before it passed through the feed
pump that forced it into the boiler, but by our present Invention the full boiler
pressure is put on the water before it gets heated to the higher temperatures.
By way of example we have upon an accompanying sheet of explanatory drawings
shown in side elevation a set of quadruple-expansion screw-propeller engines as fitted
with apparatus for carrying out our present Invention and will refer thereto in the
following description of our improvements, premising that the same reference numerals
are used to mark the same or like parts wherever they are repeated.
When working the steam successively through the four cylinders, 1, 2, 3, 4, of a
quadruple-expansion engine such as is shown in the drawing, we prefer to first pump
the feed water by means of the main-engine feed pumps, 5, and to deliver it thence
with a moderate pressure through the pipes, 6, 7, into a feed heater, 8, of a kind made
and operating as described in some of our earlier Specifications, in which heater the
feed water is brought into immediate contact with steam. The steam used in this feed
heater, 8, is supplied by a pipe, 9, connected to the exhaust pipe, 10, of the third-stage
cylinder, 3, the steam having been worked through three stages of expansion. From
the contact heater, 8, as it may be termed, the partly heated feed water passes by a
pipe, 11, to a set of donkey pumps, 12, by means of which sufficient pressure is imparted
to it to enable it to enter the boilers; and it proceeds thence by a pipe, 13, to one
compartiment, 14, of a feed-heater casing, 15, made with two compartments, 14, 16,
through which the feed water passes in succession. These compartiments, 14, 16, are

page_text: surface feed heaters, the steam by which the heat is applied acting in tubular apparatus
which we prefer to arrange and construct as described and shown in our complete
specification 6007 of 1887. The steam acting in the tubes of the lower compartment, 14,
is supplied by a pipe, 17, connected to the exhaust pipe, 18, of the second-stage
cylinder, 2; and that acting in the tubes of the upper compartment, 16, is supplied by
a pipo, 19, connected to the exhaust pipe, 20, of the first-stage or high-pressure
cylinder, 1. Thus the feed water having been first heated by steam of moderate
heat and which has worked in three cylinders, is secondly further heated by steam of
higher temperature and which has worked in only two cylinders, and is finally still
further heated by steam of still higher temperature and which has worked in only one
cylinder.
When surface feed heater is used the steam working in it becomes partly condensed
and we dispose of the water of condensation thus arising, in a manner to utilise the
heat in it as much as possible. Thus we lead the water from the steam tubes of the
highest temperature feed heater, 16, by a pipe, 21, fitted with a suitable regulating
cock into the steam inlet compartrient of the next lower-temperature feed heater, 14,
in which compartment the pressure is lower than in the higher-temperature feed
heater, 16. The water thus transferred may more or less evaporate but whether it does
so or not it will impart heat to the feed water which at that stage is cooler than in the
upper feed heater, 16. In a similar way, water proceeding from the steam tubes of
the second or ntermediate feed heater, 14, is led by a pipe, 22, fitted with a suitable
regulating cock into the lowest-temperature feed heater, 8; or if found preferable
this water with any air or vapor accompanying it may be led by a pipe, 23, direcily
into the main condenser, 21. In some arrangements of the apparatus the water of
condensation due to the feed-heating steam may be led into the hot well or into a vessel
provided with an outlet for air into the atmosphere.
We prefer to fit our improved apparatus with automatic regulating devices, and
with various connections and stop valves such as will allow of different parts being
thrown out of connection without stopping the feeding of the boilers. Thus the
steam to work the donkey pumps, 12, may be supplied by a pipe, 25, having ou
it a regulating valve worked by a float within the feed heater, 8. Or the steam to
work the donkey pumps, 12, may be supplied by a pipe, 26, provided with a regulating
valve, 27, worked by a float in the hot well, 28. The feed water may be pumped from
the main-engine pumps, 5, directly to the boilers through a pipe, 29, connected to the
delivery pipe, 6, of those pumps. When the feed water passes through all the heating
apparatus it proceeds to the boilers from the highest-temperature compartment, 16, by
pipes, 30, 31, the latter being also connected to the donkey-pump delivery pipe, 13, and
stopcocks being provided which can be set to let the water proceed directly to the
boilers without passing through the two higher-temperature feed heaters, 14, 16, if
wished. These connections adimit not only of examining and repairing any part of the
apparatus without stopping the feeding of the boilers, but also of testing the operation
of each part with the view of adjusting and regulating it so as to obtain the best and
most economical results.
In modifying the arrangements shown in the drawing and herein before described to
suit a triple-expansion engine we use two feed heaters, either those herein before
referred to as compartments, 10, 14, or those referred to as 14, 8. All the feed heaters
even when there are three or more may be surface feed heaters; and when all are
surface feed heaters the feed water may be pumped with sufficient pressure to enter the
boiler before passing through any of thein. In all cases if found convenient or
desirable all the pumping of the feed water may be effected by donkey pumps or
pumps separate from those of the main engines.
Having now particularly described and ascertained the nature of our said Inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:-
1. The improved combination of apparatus in connection with compound steam
engines and comprising arrangements for heating the feed water for the boilers at

page_text: successive stages with portions of steam which have worked to different extents, the
feed water being pumped to its highest pressure before passing through one or more
of the higher heating stages substantially as herein before described.
2. The improved combination of feed-heating apparatus connected with compound
steam engines and comprising one or more surface feed heaters with feed pumps
arranged to pump the feed water with sufficient pressure to enter the boiler before it
passes through any such surface feed heater or heaters substantially as herein before
described.
3. In feed-heating apparatus working with two or more heating stages in connection
with compound steam engines, providing pipes and stop valves to allow of a part or
parts of the apparatus being disconnected without stopping the feeding of the boilers,
substantially as hereinbefore described.
1L T
1000
EDMUND HUNT,
Applicants' Agent.