IMPROVE- MENTS IN AND CONNECTED WITH STEAM ENGINES
Year: 1876

page_text: LETTERS PATENT to George Weir and James Weir, both of Glasgow, in tho
County of Lanark, North Britain, Engineers, for the Invention of "IMPROVE-
MENTS IN AND CONNECTED WITH STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said George Weir and Jaines
Weir at the Office of the Commissioners of Patents on the 28th December
1876.
GEORGE WEIR and JAMES WEIR, both of Glasgow, in the County of Lanark,
North Britain, Engineers. "IMPROVEMENTS IN AND CONNECTED WITH STEAM
ENGINES."
This Invention has for its object to economise fuel by improvements relating to
the heating of the feed water, and it consists of 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, or some modifications of them, are appliable to ordinary
condensing and non-condensing engines and to engines working on the compound
system.
In carrying out the Invention the feed water is pumped into the upper part of a
vessel arranged for separating the air from it. This air separator has connected to
it at the intended level of the water in it a small pipe with a stop-cock which is
adjusted to let out air in proportion to its accumulation or nearly so. The water
is led by a pipe proceeding from the bottom of the air separator to the top of the feed
heater, and enters that vessel by a valve which is loaded by a spring or otherwise
so as to maintain in the pipe a certain pressure above that in the feed heater.
The valve is, by preference, one having a flange or disc bearing up against a flat
seat on a pipe projecting a little down into the heater, and when it opens the water
issues in a thin sheet, which striking the sides of the vessel is broken into spray.
The descent of the water through the vessel is retarded by perforated diaphragms
or equivalent means, and it passes off from the bottom to pumps which feed it into
the boilers. When the water has had the air separated from it as herein-before
described, it much more readily takes up heat from the steam in the feed heater.
Any suitable arrangement may be adopted for separating the air; thus for
Din G.71

page_text: example, a pipe may be led from the feed heater to the condenser or air pump, or
hot well; it is however preferable to separate the air from the water before it enters
the feed heater.
It is advantageous in any case to have a small pipe with a stop-cock between
the feed heater and condenser, as it affords a convenient means of controlling or
regulating the action in the feed heater, particularly when the steam supplying the
feed heater is of low pressure.
.
It is also in some cases advantageous to connect a pipe by which air leaving the
separator may pass to the second or hot feed pump or pumps in order to prevent
concussive action in those pumps.
When the improvements are applied to compound engines the feed heater is
according to one modification arranged to receive steam for heating the feed water
from the receiver or intermediate steam chamber between the high-pressure and
low-pressure cylinders, the admission of the steam being regulated by a check valve
which only opens when the steam in the chamber is above the pressure in the feed
heater.
There may be two or more feed heaters in connection with one set of engines, and
arranged to receive steam at different stages of the steam's progress through the
engines, whilst the feed water is pumped through them in succession so as to pass
later through that or those receiving steam earlier.
In a modified arrangement applicable to a single cylinder a port is made in the
side of the cylinder at the middle of its length or other suitable position, and in a
passage leading therefrom to the feed henter there is fitted a check valve. The
steam acts on the piston in the ordinary way during the first part of its stroke, but
on the piston passing the port in the side some of the steam has access to the feed!
heater, and is productive of more benefit in heating the feed water than corresponds
to the diminution of pressure during the latter part of the piston's stroke due to its
leaving the cylinder.
A similar arrangement is also applicable to compound engines, either in con-
nection with the high-pressure cylinder only, or with both cylinders with a separate
feed heater for each.
:
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Weir and James Weir in the Great Seal Patent Office on the
26th June 1877.
GEORGE WEIR and JAMES WEIR, both of Glasgow, in the County of Lanark, 3
North Britain, Engineers. "IMPROVEMENTS IN AND CONNECTED WITH STEAM
ENGINES."
Our said Invention has for its object to economise the fuel used with steam
engines by improvements relating to the heating of the feed water, and it comprises
arrangements whereby the feed water is heated in an advantageous manner by a
part of the steam which has operated to a certain extent in the engine, but which
part is withdrawn from the remaining steam before the work of the latter is
completed.
Our improvements, or some modifications of them, are applicable to ordinary
condensing and non-condensing engines, as well as to engines working on the
compound system.
In carrying out our Invention in the case of a condensing engine provision is
. made for the separation of air from the feed water before admitting the latter into
the heating chamber, into which chamber it is pumped through an admission valve
loaded by a spring or otherwise, so as to maintain in the pipe a certain pressure
above that in the heating chamber.
The water, by preference, enters the heating chamber or feed heater at the top,
and descending in spray or in small streams through perforated diaphragms, is led

page_text: may be women now pump pumps WATION
feed it directly into the boilers.
When our improvements, are applied to compound engines the feed heater is
according to one modification arranged to receive steam for heating the feed water
by immediate contact from the receiver or intermediato steam chamber between the
high-pressure and low-pressure cylinders, the admission of the steam being regulated
by a check valve, which opens only when the steam in the chamber is above the
pressure in the feed heater."
There may be two or more feed heaters in connection with one set of engines,
and arranged to receive steam at different stages of the progress of the steam
through the engines, whilst the feed water is pumped through them in succession
so as to pass later through that or those receiving steam of higher temperaturo.
In a modified arrangement applicable to a single cylinder or non-compound
engine a port is made in the side of the cylinder at the middle of its length or other
suitable position or positions, and a passage provided with a check valve leads
therefrom to the feed heater. The valve in the feed heater passage may be arranged
not to open until some predetermined portion of the stroke has been accomplished
by the piston.
A similar arrangement is also applicable to compound engines, either in con-
nection with the high-pressure cylinder only, or to both cylinders with a separate
feed heater for each.
In all the modifications of our improved arrangements the steam withdrawn is
productive of more benefit in heating the feed water than corresponds to the
consequent diminution of pressure during the completion of the working of the
remaining steam in the engine.
Various parts not herein-before described but forming part of our Invention, and
contributing if not essential to the beneficial results will be best understood from
the more detailed description of our improvements hercin-after contained.
And in order that our said Invention and the manner of performing the same
may be properly understood, we hereunto append two Sheets of explanatory
Drawings, to be herein-after referred to, and representing portions of steam engines
as fitted with our improved apparatus. In these Drawings the same reference
numerals are used to mark the same or like parts wherever they are repeated.
Figures 1 and 2 on Sheet 1 of the Drawings are a plan and clevation of a set of
two cylinder compound engines.
Figure 3 on Sheet 2 is a vertical section of a single cylinder showing the appli-
cation of our Invention to it.
Figure 4 is an enlarged vertical section of the feed heater, and Figures 5 and 6
are enlarged vertical sections of the air separator and hot feed pump, whilst Figure 7
is a vertical section of a modification comprising feed heater and air separator in
one vessel.
The apparatus shown enlarged in Figures 4, 5, 6, on Sheet 2, is the same as that
shown applied to the compound engines on Sheet 1, and is also applicable to the
single cylinder, Figure 3, Sheet 2.
The engines shown in Figures 1 and 2 are in general arrangement according to a
common type of screw propeller engines, with two inverted cylinders 1, 2, respectively
high pressure and low pressure, and having the intermediate chamber or casing 3
formed partly round the high-pressure cylinder 1, and partly between the two
cylinders. From the intermediate casing 3 a pipe 4 provided with a check valve,
which can if required be prevented from opening by a screw spindle 5, leads steam
of intermediate pressure to the feed heater 6, which is represented as a cylindrical
vessel, but which may be of any convenient form. Inside the feed heater 6 the
steam comes into direct contact with the feed water, which descending from the top
is broken into spray or small streams by passing through a number of perforated
diaphragms 7. The feed water being withdrawn from the condenser 8 in the
ordinary way by the air pump 0 is led directly from the hot well or air pump
discharge into one of the feed pumps, herein-after termed the cold feed pump 10,
9

page_text: and is forced by this pump into the feed heater 6. On its way to the feed heater
however the feed water passes first (excepting when the modification shown in
Figure 7 is used) by the pipe 11 into an air separator 12, Figure 5, which is a
closed vessel of sufficient strength, having the inlet at one side a little below the
intended level of the water, whilst the outlet is at the bottom, and communicates by
a pipe 13 with the top of the feed heater G. At about the height of the intended
water level a stop-cock 14 is fitted to the air separator, and a pipe from it passes
to the hot well or atmosphere, the stop-cock 14 being adjusted to let out air from the
separator in proportion to its accumulation therein, or nearly so. The water enters
the feed heater 6 by a valve 15, which is by preference one having a flange or disc
bearing upagainst a flat seat on the end of a pipe projecting a little down into the
heater, and when it opens the water issues in a thin sheet, which striking the sides
of the vessel is broken into spray. The spindle of the valve 15 passes out through
a stuffing box, and has a spring 16 applied to it to maintain in the pipe 13 an
excess of pressure over that in the feed heater. The water descends through the
feed heater 6 in direct contact or mixture with the steam, from which it takes up
heat the more readily in consequence of having had the air separated from it as
herein-before described, and the heated water passes off from the bottom of the feed
heater by a pipe 17, which leads it to a second or hot feed pump 18 Figure 6 (or
set of pumps), by which it is pumped into the boilers.
Any suitable arrangement may be adopted for separating the air from the feed
water; thus for example, as shown in Figure 7, a pipe 19 with a stop-cock may be
led from the top of the feed heater 6 to the condenser or air pump or hot well, and
in that case we prefer to fit a conical or other suitably shaped shell 20 in the top of
the feed heater with perforations at its lower part to check and hold the feed water
a little on its first entering the feed heater, so that there may be an opportunity for
the air to separate. We however consider it best to separate the air from the water
before the latter enters the feed heater by using apparatus more or less like that
shown in Figure 5, and herein-before described. At the same time we must remark
that it is advantageous in any case to have a small pipe 21 (Figure 4), with a stop-
cock between the top of the feed heater 6 and the condenser 8, as it affords a con-
venient means of controlling or regulating the action in the feed heater, particularly
when the steam supplying the feed heater is of low pressure. For a similar purpose
a pipe and stop-cock 33 should be fitted to the lower part of the modified feed
heater shown in Figure 7.
It is also in most cases advantageous to connect a pipe 22, Figures 5, 6, from the
upper or air space of the air separator 12 to the under side of the inlet valve of the.
hot feed pump 18, in order to prevent concussive action in that pump. A pet or
gauge cock 32 is fitted to the air separator 12 at a level between the pipes 14, 22,
for use in ascertaining the level of the water..
In order to prevent concussive action of the valve 5 in the pipe 4, by which the
steam enters the feed heater 6, we make the valve as shown enlarged, and in
vertical section in Figure 8. The valve seat is inade with a cylindrical shell
having an opening cut or formed round it, the top part, which is closed, being
connected by internal feathers to the lower part. The valve is a cylindrical cap
working on the cylindrical part of the seat, its bottom edge when the valve is quite
closed bearing down upon a shoulder or step. The valve is raised by steam leaking
as it were between the cylindrical surfaces and into the upper part, and as this
leakage cannot take place rapidly, abrupt changes of pressure do not make the valve
move suddenly.
In the modification to be used when each portion of steam acts in only one
cylinder, and which is shown in Figure 3, there is formed in the side of the cylinder
at the middle of its length a port 25, which is sub-divided by oblique bars on its
inner fuce so that the piston rings may not catch in it, and which communicates
with the pipe 4 leading to the feed heater 6 by a valve box 26 having in it a
valve 27, the spindle of which passes out through a stuffing box and has a
spring 28 applied to it externally. This spring 28 is adjustable by means of a

page_text: hand wheel nut 29 screwed upon a spindle 30, which is also screwed through a fixed
cross head 31, and has a hand wheel fixed on its outer ond. The inner end of the
screw spindle 30 serves as an adjustable stop for limiting the extent of opening of
the valve 27, whilst the spring 28 causes the valve to close whenever the pressuro
in the cylinder gets below that for which it is adjusted. This arrangement is
suitable for engines in which the steam is cut off earlier than at half stroke ; and
when applying apparatus of the kind to engines in which the steam is cut off later
than at half stroke provision should be made for keeping the port 25 or valve 27
closed until a later period of each stroke. This may be done by fixing lap plates
upon the piston and providing pockets for these plates to enter in the cylinder
ends or covers; or by applying a suitable positive motion to the valve 27 from a
cam or eccentric moved by the engine; or the positive motion may be imparted to
an additional valve 27, the valve 27 being left free to close on the pressure in the
cylinder, diminishing below a certain point.
The arrangement of positively moved valve for determining the admission of
steam into the feed heater, and herein-before described as applicable to the non-
compound engine, is also in some cases applicable to compound engines; for example,
when there is little or no steam space between the high-pressure and low-pressure
cylinders.
When two or more feed heaters are employed in the same set of engines that or
those for the higher temperatures may be made with tubular or other metallic
separation between the feed water and steam instead of the steam being brought
into direct contact with the water, as herein-before described.
In the case of non-condensing steam engines our improved feed heating arrange-
ments, involving the use of steam withdrawn prior to the termination of the
expansive working, are by preference applied to feed water previously heated by
the final exhaust steam in any known kind of apparatus.
Our improved feed heating apparatus constructed or arranged substantially as
shown in Figures 4, 5, and 6 of the accompanying Drawings, and heroin-before
described, is applicable with some advantage when supplied with a portion of tho
finally exhausted steam, although as we believe the benefit derivable is greater
when the steam supplied to it is withdrawn before the final exhaust.
Having thus particularly described our said Invention and the manner of per-
forming the same, we have to state that we do not restrict ourselves to the precise
details herein described and delineated, but that what we believe to be novel and
original, and claim as the Invention secured to us by the herein-before in part recited
Letters Patent is,―
1. The heating of the feed water of steam engines by improved apparatus, sub-
stantially such as is herein-before described, and in which the heating is effected by
a part of the steam withdrawn from the remainder before the working expansion of
the latter is completed.
2. The combining of air-separating apparatus with the feed heater, substantially
as and for the purposes herein-before described.
3. The combining of the feed heater with feed pumps arranged to act on the
water both before and after it passes through the feed heater, as herein-before
described.
4. The arranging of the loaded valve (15) to prevent the feed water from entering
the feed heater excepting under a pressure higher than that in the feed heater,
substantially as and for the purposes herein-before described.
5. The leading of the pipe (22) from the air separator (12) to the hot feed
pump (18), substantially as and for the purposes herein-before described.
6. The constructing or arranging of the valve (5) and its seat, by which the
steamhas access to the feed heater, substantially as and for the purposes herein-
beforedescribed with reference to Figure 8 of the accompanying Drawings.
7. The withdrawing of steam for heating feed water when each portion of steam
acts in only one cylinder by means of apparatus constructed and acting, substan-

page_text: tially as herein-before described with reference to Figure 3 of the accompanying
Drawings.
In witness whereof, I, the said James Weir, on behalf of the said George
Weir and myself, have hereunto set my hand and seal, this Twenty-third
day of June, in the year of our Lord One thousand eight hundred and
coventy SAVAN
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
JAMES WEIR. (LS)