IMPROVEMENTS IN AND APPARATUS FOR FEEDING LOCOMOTIVE AND OTHER STEAM BOILERS OR GENERATORS, APPLICABLE ALSO FOR RAISING AND FORCING WATER FOR OTHER PURPOSES
Year: 1876

page_text: LETTERS PATENT to Edward Hamer and James Metcalfe, both of Aberyswith,
Cardigan, and Edward Davies, of Pontypridd, Glamorgan, Wales, for the In-
vention of "IMPROVEMENTS IN AND APPARATUS FOR FEEDING LOCOMOTIVE AND
OTHER STEAM BOILERS OR GENERATORS, APPLICABLE ALSO FOR RAISING AND
FORCING WATER FOR OTHER PURPOSES."
Sealed the Sth August 1876, and dated the 14th February 1876.
PROVISIONAL SPECIFICATION left by the said Edward Hauer, James
Metcalfe, and Edward Davies at the Office of the Commissioners of Patents on
the 14th February 1876.
EDWARD HAMER and JAMES METCALFE, both of Aberyswith, Cardigan, and
EDWARD DAVIES, of Pontypridd, Glamorgan, Wales. "IMPROVEMENTS IN AND
APPARATUS FOR FEEDING LOCOMOTIVE AND OTHER STEAM BOILERS OR GENERATORS,
APPLICABLE ALSO FOR RAISING AND FORCING WATER FOR OTHER PURPOSES."
This Invention has reference more especially to an improved form of injector for
feeding boilers and also for utilizing exhaust steain from the engines for that
purpose.
This
In feeding boilers by means of the injector the supply tank is usually placed at or
near the level of the injector, and in order to enable a given weight of water to
enter the boiler a certain minimum weight of steam must be condensed by it or
mixed with it. The amount of this minimum weight of steam is dependent upon
the pressure in the boiler and upon the initial temperature of the supply water, as
well as upon its height above or below the injector; or in other words, upon the
temperature and absolute pressure of the supply water, these being in practice
generally about the same as the atmospheric temperature and pressure.
minimum weight of steam when combining with a given weight of water raises its
temperature in proportion to the weight of the steam to that of the water, and the
difference between the initial temperature of the supply and the final temperature
of the combined jet is thus necessarily very considerable, and in actual practice it
is generally still greater than the minimum necessary, it being the custom of
engineers to allow the injector to continue to work with whatever quantity of steam
is found to start it satisfactorily; thus in most cases the proportion of steam to
water is considerably greater than necessary, and consequently the final temperature
is made to approach proportionally nearer the boiling point. From these con-
siderations it is evident why the injector will not work with supply water above a
[Price 6d.]

page_text: certain initial temperature, inasmuch as the minimum necessary proportion of
steam would then heat it beyond the boiling point corresponding to the absolute
pressure at which the water is supplied, and the steam rushes back to meet the
water.
In connection with heating feed water with exhaust steam two different methods
have been adopted; first, before the feed water enters the injector, that is, generally
by turning the exhaust steam into the feed tank; secondly, by heating the feed
water as it passes through the injector. Both methods are open to the objection
that they only utilize the exhaust steam for heating the feed water through an
inconsiderable fraction of the interval between the initial temperature of the supply
and that of the boiling point corresponding to the pressure of the exhaust. The
former method is also objected to on the ground that if the water is slightly over-
heated the injector cannot be got to work. In the second method the amount of
the heating is uncertain, inasmuch as it depends on the care of the engineer in
In both cases
reducing the supply of boiler steam to the minimum necessary.
boiler or "live steam only is used for imparting to the combined jet sufficient
velocity to overcome the pressure in the boiler. In our Invention these objections
are removed by the application and use of the following principles and apparatus.
It is known that when steam is condensed a vacuum is formed, the amount of
which is dependent upon the temperature of the water of condensation, and when
this temperature is low, and the vacuum therefore good, it is found that the velocity
of steam flowing into it is approximately the same for all pressures of steam; thus
the amount of momentum generated in a pound of steam at different pressures
flowing into a good vacuum does not differ in anything like the proportion of the
pressures.
"
The
In our apparatus we avail ourselves of the above principle, and construct an
injector similar to those using boiler steam, but having the area of the steam
passages larger in proportion to the water passage and "throat or discharging
nozzle, so as to provide for the larger volume of the exhaust, in order to pass about
the same weight of exhaust as would have been used of boiler steam.
momentum thus generated in the exhaust in flowing into the vacuum, together
with that of the water, which has also acquired a considerable momentuin by
flowing into the same vacuum, is imparted to the combined jet, thus giving it a
high velocity. In some cases this velocity is sufficient to carry it into the boiler,
but if the velocity is not sufficient it is now supplied at a temperature closely
approximating to the boiling point (corresponding to the pressure of the exhaust
steam used, and at a pressure corresponding to the velocity which the combined jet
has acquired) to an ordinary injector, in passing through which it receives a small
quantity of boiler or pure steam, which generates in it an increment of velocity
sufficient to enable it to overcome the pressure in the boiler. It will be noticed
here that had the water been supplied at this high temperature, but only at or near
atmospheric pressure, it could not have taken up boiler steam in the second injector,
and consequently would not pass into the boiler. It will also be noticed that as
the temperature of the water supplied to the second injector is so great, after
passing it the combined jet has a higher temperature than the boiling point at
atmospheric pressure, and therefore the overflow of the second injector must be
closed, not to prevent air from entering, as is now sometimes done, but to prevent
steam from escaping from the surface of the combined jet through evaporation.
Instead of using two distinct injectors both may be combined in one; thus the
boiler steam may be introduced to the combined jet of water and exhaust (which
possesses high temperature and velocity) as it emerges from the combining cone.
We would explain that when the combined jet of water and exhaust steam,
which possesses a high temperature, is introduced to the boiler steam when one
injector only is used, advantage is taken directly of its velocity to impart an incre-
ment to it, whereas when two injectors are used this velocity is reduced to its
equivalent pressure in an intermediate receptacle, which pressure again generates
velocity whilst entering the combining chamber of the second injector. In this

page_text: intermediate receptacle is placed an overflow valve, similar to an ordinary safety
valve, to permit the escape of surplus water in case the first injector passes too
much, and this water may be taken back to the supply pipe of the first injector, and
by heating the supply water tends to regulate its action.
It is preferred to form the cones and spindle of our injectors of such a shape
that the cross sectional area of each steam space may be nearly constant for a short
interval before the steam reaches the combining chamber in order to expand the
steam fully, and thus impart to it the full velocity which it is capable of attaining
whilst entering that vacuum. If this cross sectional area diminishes, the pressure
is brought down on the surface of the water; if it increases, the velocity at the
smallest part is partially lost before it reaches the water.
We prefer to introduce the steam at more than one point of the jet, and thus by
having several vacuum or combining chambers we are able to maintain a better
vacuum in the first than the last, thus obtaining more momentum from a given
weight of steam. And in order to maintain the vacuum in these different chambers
distinct, it is preferred to expand very slightly each combining cone at its termi-
nation; in fact, to make a throat piece at the end of it to provide for the slightly
enlarged area of the jet, in consequence of the reduction of velocity caused by
passing from a greater into a lesser vacuum, its action, in fact, being exactly the
same as that of the "throat," only in a lesser degree, the greater vacuum corre-
sponding to the atmospheric pressure at overflow, and the lesser to the boiler
pressure on the other side of the "throat."
We may apply the exhaust or boiler steam internally or externally with regard
to the water jet, or both.
Our Invention also includes self-acting regulating valves for regulating the steam
and water supply, and the catch and back pressure valves necessary to intercept the
exhaust as it flows out at a considerable fraction of the final pressure which exists
in the cylinders, and to prevent condensed steam being admitted into the cylinders,
as well as arrangements for superheating steam used.
We also include in this Invention an arrangement for regulating the supply of
blast to the requirements of the engine by inserting into the blast pipe a spindle
worked by a screw or other equivalent means from the foot plate of a locomotive
engine.
This Invention is also applied for heating feed water when supplied by a pump,
and for raising and forcing water and fluids generally.
"
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Edward Hamer, James Metcalfe, and Edward Davies in the Great Seal
Patent Office on the 11th August 1876.
EDWARD HAMER and JAMES METCALFE, both of Aberyswith, Cardigan, and
EDWARD DAVIES, of Pontypridd, Glamorgan, Wales. "IMPROVEMENTS IN AND
APPARATUS FOR FEEDING LOCOMOTIVE AND OTHER STEAM BOILERS OR GENERATORS,
APPLICABLE ALSO FOR RAISING AND FORCING WATER FOR OTHER PURPOSES."
This Invention consists of an improved form of apparatus or injector for feeding
boilers with water by means of the exhaust steam from the engine instead of the
' live or boiler steam now used.
"
When boilers are fed by means of an injector the supply tank is usually placed
at or near the level of the injector, and in order to enable a given weight of water
to enter into the boiler a certain minimum weight of steam must be condensed by
it or mixed with it. The amount of this minimum weight of steam is dependent
upon the pressure in the boiler, and upon the initial temperature of the supply
water, as well as upon its height above or below the injector, or in other words upon..
the temperature and absolute pressure of the supply water, these being in practice
generally about the same as the atmospheric temperature and pressure: This

page_text: minimum weight of steam when combined with a given weight of water raises its
temperature in proportion as the weight of the steam used is to that of the water,
and the difference between the initial temperature of the supply and the final
temperature of the combined jet is thus necessarily very considerable, and in actual
practice it is generally still greater than the minimum necessary, it being the custom
of engineers to allow the injector to continue to work with whatever quantity of
steam is found to start it satisfactorily; thus, in most cases, the proportion of steam
to water is considerably greater than necessary, and consequently the final tempera-
ture is made to approach proportionally nearer the boiling point. It is known that
the injector will not work with supply water above a certain initial temperature,
inasmuch as the minimum necessary proportion of steam would then heat it beyond
the boiling point corresponding to the absolute pressure at which the water is
supplied, and the steam would consequently rush back to meet the water.
For heating feed water with exhaust steam two different methods have been
suggested. The first mode is before the feed water enters the injector, that is,
generally by turning the exhaust steam into the feed tank; secondly, by heating
the feed water as it passes through the injector. Both of these methods are open to
the objection that they only utilize the exhaust steam for heating the feed water
through a fraction of the interval between the initial temperature of the supply and
that of the boiling point corresponding to the pressure of the exhaust. The former
method is also objected to on the ground that if the water is slightly overheated the
injector cannot be got to work. In the second method the amount of the heating is
uncertain, inasmuch as it depends on the care of the engineer in reducing the supply
of boiler steam to the minimum necessary. In both cases boiler or "live" stcam
only is used for imparting to the combined jet sufficient velocity to overcome the
pressure in the boiler. In our present Invention these objections are removed by
the application and use of the following principles and apparatus:-
It is known that when steam is condensed a vacuum is formed, the amount of
which is dependent upon the temperature of the water of condensation; and when
this temperature is low, and the vacuum therefore good, it is found that the velocity
of steam flowing into it is approximately the saine for all pressures of steam; thus,
the amount of momentum generated in a pound of steam at different pressures
flowing into a good vacuum does not differ in anything like the proportion of the
pressures.
Now our Invention consists of constructing an improved injector or apparatus
capable of feeding boilers entirely by means of the exhaust steam from the
cylinder, instead of using "live" steam direct from the boiler, as is now the
practice.
Our improved injector or apparatus differs from ordinary injectors, firstly, in
having no communication with the "live" steam space of the boiler for the purpose
of drawing steam from it for generating velocity; and, secondly, in having the final
cross sectional area of the steam passage or nozzle much larger in proportion to that
of the water passage, and to that of the "throat" or smallest section of the dis-
charging cone than is the practice in ordinary injectors, so as to provide for the
larger volume of the exhaust steam, in order to pass about the same weight of
exhaust as would have been used of "live" or boiler steam, for it will easily be
understood that though the velocity of the particles of exhaust steam on leaving
the steam nozzle and entering the vacuum formed in the combining cone may be
approximately as great as if boiler steam of considerable pressure were used, yet the
weight or quantity of steam passed through a given area will be less in proportion
to the inferior density of the exhaust steam, hence the necessity for increasing the
proportion between the final cross sectional area of the steam nozzle and the smallest
cross sectional area of the discharging cone, which we shall call the "throat," so as
to preserve about the same or an even greater proportion between the weight of
steam and weight of water passed, as is usual with ordinary injectors supplied with
"live" or boiler steam.
Having thus explained the principle and nature of our Invention we will now by

page_text: the aid of the accompanying Drawings describe particularly the means whereby the
same may be performed or carried into effect (the same letters of reference in each
of the Figures 1 and 2 of the said Drawings indicating the same or corresponding
parts), and before we describe our said improvements we will enumerate the parts
of one form of ordinary injector, which are common to and to be found in our
improved apparatus or injector, and which parts are as follows:--An injector
usually consists of a casing or pipe A, open at both ends, and having three branches
cast upon it, one of these branches in ordinary injectors being connected with the
steam space of the boiler, so as to draw "live" steam therefrom, another branch
with the water supply, and the third with the overflow. At the upper end B a
stuffing box is fitted, through which passes a cylinder C fitted tightly into the
casing between the first and second branches, so as to form a partition between
them. This cylinder is capable of sliding up and down along the axis of the casing,
and is actuated by a screw D or other convenient means. The upper part of the
cylinder is pierced by holes E opposite to the first branch to admit the steam
entering through it into the interior of the cylinder, from which it passes into the
steam nozzle F, which is screwed into the lower end of the cylinder. At its upper
end is another stuffing box, through which passes the steam spindle G, and it is
fitted into the axis of the cylinder. This spindle is raised and lowered by means of
a screw, its lower end being held in position by three stays H attached to the
cylinder, and the point is made to fit into the steam nozzle in order to act as a
valve or regulator. The part passing through the nozzle is brought to a sharp
point, which assists in forming and maintaining the vacuum in the combining
chamber, into which it projects. The point of the steam nozzle is situated below
the second or water branch, and immediately below this branch surrounding in part
the steam nozzle is the combining cone K, into the upper part of which the former
fits tightly when the cylinder is pressed down; thus, the movement of the cylinder
is made to stop and to regulate the flow of water as the spindle does that of the
steam. The lower end of the combining cone converges to form a nozzle, through
which the combined jet of water and steam rushes across a short interval before it
is received by the "throat" piece or discharging cone L, having a slightly bell-
mouthed top to receive the jet until the narrowest part (throat) reached, after
which it gradually enlarges so as to diminish the velocity of the jet without shock,
and thus convert it into pressure, so as to enable it to overcome the pressure in the
boiler. At the bottom of this cone or in some other convenient position is placed a
valve to prevent the water running back from the boiler when the injector is not
at work.
All the above cones should have their axes exactly in the same straight line, and
the combining and discharging cones may be turned out of the casing, or may be
fitted into it, as most convenient. The inner surfaces of all the cones should be.
made perfectly smooth, their larger ends should be rounded off to avoid loss of
power from contraction, and it is advisable to reduce the smaller ends to as fine an
edge as possible. The space between the combining and discharging cones is in
communication with the third or overflow branch, which allows any excess to run
to waste, and assists in establishing the current when starting.
Figure 1 is a full size section of one form of our improved apparatus or injector.
broken off at the stuffing box of the steam cylinder. This injector, as will be seen
by the Drawing, has not any "live" steain branch, but the steam branch which in
the ordinary injector is connected with the steam space of the boiler, so as to draw
"live" steam therefrom, is in our improved apparatus or injector connected with
the exhaust pipe or ports of the steam engine, and receives a part of the exhaust
steam as it escapes to the atmosphere, and works the feed water into the boiler
against a pressure of from 70 to 80 lbs. per square inch.
In the case of a locomotive having a blast pipe, and where the exhaust steain
possesses a pressure greater than that of the atmosphere, the pressure against which
the injector will work the feed water into the boiler is much greater. It will also
be seen by the Drawings that we reduce the size and area of the throat of the bell-

page_text: mouthed discharging cone L and enlarge the steam nozzle F, the mouth and
upper part of the combining cone K being also enlarged to receive the steam
nozzle F.
In all cases it is necessary that for a given size of throat the final cross sectional
area of the steam nozzle must be much greater in our injectors than in injectors
working with steam direct from the boiler, as hitherto used, still the ratio between
the area of the throat and the area of the steam nozzle of our improved apparatus
or injector may be varied within certain limits so as most advantageously to suit
particular cases, according to the pressure and temperature of the exhaust.
#
The proportions shewn in Figure 1 (which Figure is drawn actual size) we have
found to answer well in which the internal diameter of the throat" is four milli-
metres, and the internal diameter of the steam nozzle is twelve millimetres, but we
have used an injector in which the diameter of the throat was eight millimetres
and that of the steam nozzle was thirty-five millimetres which also worked well.
The exhaust steam can be introduced at more than one point of the jet, and thus
by having several vacuum or combining chambers we are able to maintain a better
mean vacuum, thus obtaining more momentum from a given weight of steam. This
is done by adding a second combining cone M, as shewn in Figure 2 (this Figure 2
is not drawn to scale), an additional supply of exhaust steam being introduced
between each. Thus, in the first combining chamber a better vacuum obtains than
in the second owing to its being colder, and the steam flowing into it attains a
greater momentum than an equal amount flowing into the second. It is evident
that more than two combining cones may also be used:
The action of the apparatus is as follows:-The water is allowed to flow through
the opening marked on the Drawing "water branch," into the combining cone K
and out at the opening marked "overflow branch," the exhaust steam is then turned
on and enters through the opening marked "exhaust steam branch," (in the case of
the injector represented in Figure 2, also through the opening marked "additional
exhaust steam branch" after a current has been established through the chamber F).
The spindle is now slightly raised or withdrawn, allowing the steam to pass from
the cylinder through the nozzle F into the combining cone K, when the said steam
comes into contact with the water there, and is condensed and forms a vacuum
there which causes a larger volume of water to be drawn in and the steam to rush
in with increased velocity. The enormous momentum thus generated in the
exhaust steam in flowing into this vacuum, together with that of the water, which
has also acquired a considerable momentum by flowing into the same vacuum, is
imparted to the combined jet, thus giving it a high velocity and enabling it to pass
through the "throat" and into the boiler against great pressure.
As a considerable proportion of the exhaust steam is returned to the boiler, it is
scarcely necessary to remark that a large saving of fuel results.
The exhaust steam may be brought to the injector in any way most convenient,
but it is important that such steam be kept as dry as possible.
The best results are obtained by the application of the pipes, catch valves, and
receivers, as described in the Specification of Letters Patent, dated 25th August
1875, No. 2984, granted to James Metcalfe, Edward Hamer, and Richard Metcalfe,
which application and arrangement we have represented in Sheet 2, Figures 3, 4,
and 5.
Although we have described only one form of our improved apparatus or injector,
variations in shape and form may be made without departing from the principle of
our Invention, as for example, in some cases it is found convenient to dispense with
the steam spindle.
As in the case of ordinary injectors the disposition of the steam and water may
be reversed, that is, the steam may surround the water; but this arrangement
is not found so convenient or reliable as when the steam is enclosed by the water.
Our present Invention is also applicable for raising and forcing water and other
fluids generally.
Although in our Provisional Specification we stated that our Invention-included

page_text: self-acting regulating valves for regulating steam and water supply, and the catch
and back pressure valves necessary, we do not desire to make any claim thereto in this
Specification, nor do we make any claim to the arrangement for regulating the
supply of the blast by inserting a spindle into the blast pipe to be worked from
the foot plate of the engine.
Having thus described and particularly ascertained the nature of our said In-
vention and the manner in which the same is to be performed or carried into effect,
we would have it understood that we are aware that attempts have been made
before the date of this our Patent to make use of exhaust steam for the purpose
of raising and forcing water by an injector in which the induction tubes (combining
cones) are of rather a larger area at their smallest cross section than that of the
steam nozzle or passage, and widen out to a larger area at their discharge ends,
and that Letters Patent were granted to Alexander Morton, dated 18th July 1867,
No. 2106, in the Specification of which said Letters Patent such an arrangement is
described; we therefore make no claim to such an arrangement of apparatus, as in
the said Specification is described; but what we desire to claim as the Invention
secured to us by the herein-before in part recited Letters Patent is, the improved
injector, herein-before described and shown in the Drawings hereunto annexed, by
means of which we are enabled to dispense with the "live" steam from a boiler
and use the exhaust steam from a steam engine to raise and force water and other
fluids either to feed the boiler or for other purposes.
In witness whereof, we, the said Edward Hamer, James Metcalfe, and Edward
Davies, have hercunto set our hands and seals, this Eighth day of August,
in the year of our Lord One thousand eight hundred and seventy-six.
Witness,
CHARLES BARLOW,
Patent Agent,
23, Southampton Buildings,
London.
EDW. HAMEI.
(L.S.)
JAMES METCALFE. (L.S.)
EDWARD DAVIES.
(L.S.)