Improvements in or relating to Ejector Condensers.
Year: 1892

page_text: Date of Application, 4th June, 1892
Complete Specification Left, 3rd Mar., 1893-Accepted, 29th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in or relating to Ejector Condensers.
I, THOMAS LEDWARD of 9 Pendrell Road Brockley in the County of Kent
Engineer do hereby declare the nature of this invention to be as follows:-
This invention consists of improvements in ejector condensers; notably in means
for regulating their capacity; also in an improved mechanism for preventing the
reflux of water into the engine cylinder; and further in improved guiding cones or
nozzles for directing the flow or impact of the exhaust steam upon the water jet.
I construct the water nozzle in two parts the inner part forming the working
nozzle and sliding within an outer casing in such manner that by approaching it
towards the mixing or combining cone or cones the exposed surface of the water
jet (and therefore the condensing power of same) becomes reduced in proportion
to the distance between the said water nozzle and the final mixing cone.
To prevent the reflux of water into the exhaust pipe and steam cylinder I attach
in the said exhaust pipe a check valve of improved construction consisting of a
disc mushroom or clack valve connected to a lever and balance weight in such
manner that the tendency of the valve to recoil is checked and the valve can move
freely both in opening and closing, without shock. I also preferably attach to the
spindle of the said valve a pointer visible from the outside which serves to show
the position of the valve, whether opened or shut; and I further construct the
whole preferably with a removable top cover to enable the valve to be examined
without disturbing the pipe joints.
Another improvement consists in surrounding the combining cone or cones with
a baffle-tube or shield to prevent the eddies formed by the incoming steam from
distorting the water jet. I construct this tube so that all or most of the steam
enters at the top and strikes downwards being guided in its course against the
water jet by specially shaped nozzles or cones so constructed that the steam
admitted into each is thoroughly condensed in its passage through that particular
nozzle as described in my Specification No. 3488 of 1890 for which Letters Patent
have been granted to me. These guiding nozzles or cones are each provided with
broad ribs on the outside to serve as an additional safeguard against the formation
of eddies or revolving currents in the steam. The guiding cones are preferably all
contained within the aforesaid baffle-tube or shield and can be lifted out with the
same when required for examination.
Dated this 1st day of June 1809
THOS. LEDWARD.
COMPLETE SPECIFICATION.
Improvements in or relating to Ejector Condensers.
I, THOMAS LEDWARD of 9 Pendrell Road Brockley in the County of Kent,
Engineer do hereby declare the nature of this invention and in what mauner
the same is to be performed, to be particularly described and ascertained in and by
the following statement :-
This invention consists of improvements in ejector condensers; notably in means.
for regulating their capacity; also in an improved mechanism for preventing the
reflux of water into the engine cylinder; and further in improved guiding cones or
nozzles for directing the flow or impact of the exhaust steam upon the water jet.
The invention as regards the means for regulating their capacity is chiefly
applicable to those condensers known as "automatic ejector condensers" in which
Price 811
:

page_text: the condensing water is not supplied under pressure but has to be drawn in and
kept in motion by the apparatus itself which utilizes the energy of the exhaust
steam while under vacuum both to draw in and eject the condensing water. As
the quantity of water drawn in by the vacuum remains always constant it is
essential that with fixed nozzles the quantity of steam admitted should also be
constant or at all events not fall below a certain minimum order to eject the said
condensing water. The quantity of steam necessary to effect this object depends
largely on the exposed area or length of the water jet therefore by varying this
length we may also vary the quantity of steam required to be admitted in order to
keep the condenser in operation, and thus adapt the apparatus to the actual
conditions of work when engines are running under various loads.
In order to secure this result I make the admission nozzle for the condensing
water movable so that it may be approached to or receded from the discharging
nozzle through which the final expulsion of the steam and water takes place.
The length of the water jet exposed to the action of the steam may thus be varied
from nothing up to any desired extent. By preference also instead of having one
long combining nozzle as in most injectors and ejectors to secure the efficient
mixing of the water with the steam, I provide a number of separate and concentric
combining nozzles of approximately similar size and shape so fitted and arranged
one with another that the incoming steam passes through an annular space between
each two combining nozzles and impinges on the water jet at such an angle as to
impel the said jet constantly forward. Each combining nozzle is made cylindrical
or nearly so for a certain portion of its length and the length and proportions of
each separate combining nozzle are such that the steam admitted into each is
thoroughly condensed in the cylindrical portion aforesaid before emerging from
one nozzle into the next one. The result of this form of construction is that by
having a sufficient number of such nozzles each complete in itself the maximum
condensing effect can be produced from a given quantity of water and if a number
of the said nozzles be shut off or put out of action the remainder will still perform
their duty without the efficiency and proper working of the condenser being
impaired thereby, the only difference when working with a smaller number of
nozzles being that less steam is condensed. To provide for regulating the capacity
of the condenser in this manner by shutting off one or more combining nozzles I
admit the jet of condensing water through a long tube sliding within the said
nozzles and moved by a screw lever or other suitable device. This inlet tube
being made to fit closely the cylindrical portion of each combining nozzle will shut
them off one after another as it approaches the final discharging nozzle and by
closing the annular orifices before mentioned will reduce the quantity of steam
admitted at the same time that it reduces the exposed area of the water jet. This
secures regularity and efficiency in working under all conditions.
Another improvement consists in surrounding the combining nozzles with a tube
or shield to prevent the eddies formed by the incoming steam from twisting the
water jet. I also construct the nozzles themselves with broad ribs or wings on the
outside to prevent any swirling of the steam and to direct it in a straight course
upon the water jet.
The exhaust steam enters at the top of this baffle tube and strikes the water
jet in an oblique direction being further guided in its course by the combining
nozzles above referred to. An additional portion of the steam may enter the
baffle tube by openings above each combining nozzle as shown in the accompanying
drawing.
The combining nozzles are preferably all contained within the aforesaid baffle
tube or shield and may be lifted out with the same by removing the top cover of
the condenser without disturbing any pipe joints.
To prevent the reflux of water into the steam engine cylinder when the condenser
is stopped I attach to the exhaust steam inlet of the condenser a special check valve
as shown in the drawing, which is so constructed with a balance weight that the
valve
may be fixed in any position, vertical, horizontal, or otherwise, without being

page_text: liable to an excessive tendency to recoil when opened and without requiring any
great force either to open or shut it. One method of constructing the valve as
shown in the accompanying drawing permits of the working parts being easily with-
drawn by having the balance weight swinging on a separate spindle from the valve
itself though in the same line with it. A slot, groove or keyway is cut on the end
of the spindle on which the valve swings, and a corresponding tongue or projection
is made on the balance weight spindle so that when pushed one into the other
.both spindles move together. When required to examine the valve the balance
weight spindle is drawn back. If no balance weight is used this slot serves con-
veniently for rocking the valve by hand to ascertain without removing it if any part
is broken or displaced as it is essential for the safety of the engine that this valve
should be kept in proper order.
In cases where the supply of condensing water is below the level of the condenser
and must be raised it may happen that the pressure of the exhaust steam will not
create a sufficient vacuum by induction through the nozzles so as to draw the water
up at starting. I therefore provide an inlet for live steam to the condenser so
that when starting it the movable tube or water nozzle may be screwed down so
as to leave only a narrow annular orifice between itself and the final discharge
nozzle. The live steam under pressure issuing through this annular orifice will
draw in the condensing water through the water nozzle and so start the apparatus.
This is an advantage consequent upon this form of construction. When the flow
of water is thus started it will be maintained by the exhaust steam alone, the water
nozzle being then drawn out to any required capacity.
Referring to the accompanying drawing
:―
E marks the inlet to the condenser of the exhaust steam as it comes from the
engine.
W is the inlet of the condensing water.
D is the discharge nozzle for the combined water and steam.
r and r, are two of the combining nozzles with outside ribs as described for
preventing eddies in the steam.
t is the baffle tube or shield for holding the aforesaid combining nozzles.
s and 31 mark the inlets of steam to the combining nozzles.
a is the outer casing or guide for the sliding water nozzle provided with a strainer
as shown.
nn is the movable water nozzle or sliding tube as described for shutting off all
or any of the steam inlets by approaching it towards the discharge nozzle D.
L shows the inlet pipe for admitting live steam to start the condenser as
described.
is the check valve to prevent a rush of water into the engine cylinder.
b is the balance weight to counteract the effect of gravity on the valve and enable
it to work freely in any position.
c is the slot or groove in the valve spindle for receiving a key or tongue-piece ag
described.
In the drawing the first combining nozzle is shown as being put out of action
and the second combining nozzle partially so, to illustrate the effect of the adjust-
ment of the water nozzle n. Although I show only four combining nozzles I
do not intend to confine myself to that number but may use any number preferably
between three and ten, nor do I intend to confine the method of adjusting the
capacity and of preventing the backrush of water, only to those condensers which
have a series of combining nozzles as herein described, because these portions of my
invention may be applied to any form of ejector condenser.
I further desire to state that I do not claim in this Specification the use of a
series of concentric and similar combining nozzles as being entirely novel, the same
having been fully described in my former Specification No. 3488 of 1890. I am
also aware that so-called "guide cones "have been previously described as aids to
the true direction of the water-jet, but I say that the combining nozzles herein
described are materially different both in construction and effect from any such

page_text: guide cones or guiding nozzles inasmuch as each one of those now described
constitutes in itself a complete combining nozzle for the thorough mixing of the
water with the steam.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
.claim is:
-;
1. The construction and combination of parts and general arrangement of ejector
*condensers having a movable water nozzle sliding within or towards one or more
combining nozzles and having on the exhaust steam inlet to condenser a balanced
check-valve all substantially as herein described and with reference to the accom-
panying drawing.
2. In ejector condensers the application and use of a movable or sliding water
nozzle so constructed that the distance between the point of outlet of the water jet
and the entrance of the discharging cone may be varied to any desired extent as
and for the purpose herein described.
3. In ejector condensers the construction and arrangement either with or without
the sliding water nozzle and check valve above mentioned of a series of combining
nozzles preferably between three and ten in number having such shape proportions
and position with regard to one another that the exhaust steam in passing through
the annular orifice left between any two of the said nozzles is caused to impinge at
a definite angle upon the central water jet for the purpose of impelling the same
forward, each of the said nozzles having an extension beyond the point of impact
of the steam which ensures the thorough condensation within its own length of the
steam admitted to it and being further provided outwardly with a number of broad
ribs or vanes to prevent eddies or revolving currents in the steam as hereinbefore
described and shown in the accompanying drawing.
4. The construction of a check-valve swinging from a slotted spindle and controlled
by an adjustable balance weight as herein described and with reference to the
accompanying drawing.
5. The construction and arrangement of the parts of ejector condensers so that
the nozzles are fitted within one outer case or tube and may be lifted bodily out
for examination without disturbing any of the pipe joints as shewn in the
accompanying drawing.
.
6. In ejector condensers the employment of a baffle tube or shield surrounding the
combining nozzle or nozzles to prevent solid particles being blown into the nozzles
and also to prevent revolving eddies in the steam as herein before described and
with reference to the accompanying drawing.
7. The employment in combination with a condenser of the above type of live
steam for the purpose of starting it in the manner herein described.
8. The application or use of all or any of the improvements herein described or
illustrated or any mere modification thereof.
Dated this 2nd day of March 1893.
THOS. LEDWARD.