Improvements in Ejector Condensers.
Year: 1890

page_text: PROVISIONAL SPECIFICATION,
Improvements in Ejector Condensers.
I, THOMAS LEDWARD of No. 9, Holdenby Road, Brockley, in the County of Kent,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to an improved apparatus for obtaining a vacuum in the
cylinders of steam engines, whereby the energy of the exhaust steam itself is utilized
to set in motion and maintain a jet of water travelling at a high velocity through a
series of nozzles, which are so arranged that the steam and water are combined
therein and act upon each other in such manner that the whole of the steam is con-
densed and a vacuum thereby formed in the exhaust steam pipe and in the cylinder of
the engine while at the same time the jet of water receives a succession of impulses
from the steam which enables it to issue from the apparatus with sufficient momentum
to overcome a considerable resistance over and above the pressure of the atmosphere
which is against it.
.
The water is admitted through a central nozzle placed at one end of the apparatus:
this nozzle is so formed as to give a round solid jet, and is called the water nozzle.
Below this and nearly touching it is a second nozzle partially enclosing the water
nozzle but leaving between the two an annular space into which the exhaust steam
can enter. This forms the first mixing nozzle and the effect of the entry of the
exhaust steam into it is that the jet of water and the steam are combined and issue in
the form of a solid liquid jet into the second mixing nozzle, which is a repetition of the
first, and so placed that an annular space for the entry of the steam exists between
the first and second mixing nozzles. A second portion of the steam enters this
annular space and mixing with the jet of water impels the same forward into a third
and similar nozzle, and so on through the whole series.
I employ any number of these mixing nozzles or cones, between every two of which
is an annular space so formed that the exhaust steam as it enters is directed and
caused to impinge upon the jet of water in such manner that the latter is constantly
urged forward, until it finally issues at a high velocity from the last nozzle.
By these means I ensure that the condensation of the steam is performed in stages:
and I further construct each combining nozzle or cone of such proportions in its
relation to the water-jet that the whole of that portion of the exhaust steam which
euters the nozzle becomes intimately mixed with and perfectly condensed by the water
before it leaves that nozzle to enter the next one.
The effect of this special form of construction is to disturb the water-jet as little as
possible, or after it has been disturbed by the mixing with it of the exhaust steam,―
to re-form the jet into a solid cylindrical shape before allowing the next following
portion of steam to act upon it. While therefore the mixing of the steam with the
water is thorough and complete, because gradually performed, the true form and
character of the jet, so necessary to the effective working of this class of machines,
are retained.
In some forms of the apparatus I employ an additional small nozzle at the entrance
of and concentric with the water-nozzle. This additional nozzle I place also in com-
munication with the exhaust steam, for the purpose, at starting, of causing a suction
through the water nozzle with the object of drawing up the water from the depth of a
few feet; and also of enabling the condenser to start more readily when placed under
water.
This, which I call the suction nozzle, remains always in communication with the
exhaust steam, and is not shut off after starting as in some other forms of ejector-
condensers where such a nozzle has been used separately with high pressure stram
from the boiler.

page_text: The utility of my invention consists in the fact that the exhaust steam from an
engine may thereby be utilized to cause a vacuum in the cylinder of the engine
without any extraneous help or mechanical accessories, such as air-pumps; and on
account of the special construction of the nozzles as described a high vacuumi may be
obtained with the minimum consumption of water.
By proper formation of the nozzles, this apparatus may be worked so that the
exhaust steam is made to force the water against a great resistance; consequently the
same form of apparatus may be used either as an ejector-condenser, an exhaust steam
pump or water-lifter, or as an injector for boiler-feeding.
Dated this 4th day of March 1890.
THOMAS LEDWARD.
Improvements in Ejector Condensers.
I, THOMAS LEDWARD of No. 9. Pendrell Road, Brockley in the County of Kent
Engineer 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:--
My invention relates to an improved apparatus for obtaining a vacuum in the
cylinders of steam engines, whereby the energy of the exhaust steam itself is utilized
to set in motion and maintain a jet of water travelling at a high velocity through a
series of nozzles, which are so arranged that the steam and water are combined therein
and act upon each other in such manner that the whole of the steam is condensed
and a vacuum thereby formed in the cylinder of the engine; while at the same time
the jet of water receives a succession of impulses from the steam which enables it
to issue from the apparatus with sufficient momentum to overcome a considerable
resistance over and above the pressure of the atmosphere which is against it.
The water is admitted through a central nozzle placed at one end of the apparatus:
this nozzle is so formed as to give a round solid jet, and is called the water nozzle.
Below this and nearly touching it is a second nozzle partially enclosing the water
nozzle but leaving between the two an annular space into which the exhaust steam
can enter. This forms the first mixing nozzle and the effect of the entry of the exhaust
steam into it is that the jet of water and the steam are combined and issue in the form
of a solid jet into the second mixing nozzle which is a repetition of the first, and
so placed that an annular space for the entry of the steam exists between the first and
second mixing nozzles. A second portion of the steam enters this annular space
and after mixing with the jet of water impels the same forward into a third and
similar nozzle and so on through the whole series.
I employ any number of these mixing nozzles or cones, between every two of which
is an annular space so formed that the exhaust steam as it enters is directed and
caused to impinge upon the jet of water in such manner that the latter is
constantly urged forward, until it finally issues at a high velocity from the last
nozzle.
By these means I ensure that the condensation of the steam is performed in stages:
and I further construct each combining nozzle or cone of such proportions in its
relation to the water-jet that the whole of that portion of the exhaust steam which
enters the nozzle is intimately mixed with and perfectly condensed by the water
before it leaves that nozzle to enter the next one."
The effect of this special form of construction is to disturb the water-jet as
little as possible, or after it has been disturbed by the mixing with it of the
exhaust steam, to re-form the jet into a solid cylindrical shape before allowing the
next following portion of steam to act upon it. While therefore the mixing of
the steam with the water is thorough and complete, because gradually performed, the
true form and character of the jet, so necessary to the effective working of this class
of machines, are retained.

page_text: In some forms of the apparatus I employ an additional small nozzle at the entrance
of and concentric with the water nozzle. This additional nozzle I place also in com-
munication with the exhaust steam, for the purpose, at starting, of causing a suction
through the water nozzle with the object of drawing up the water from the depth of
a few feet; and also of enabling the condenser to start more readily when placed
under water.
By proper formation of the nozzles, this apparatus may be worked so that the
exhaust steam is made to force the water against a great resistance; consequently
the same form of apparatus may be used either as an ejector condenser, an exhaust-
steam pump or water-lifter, or as an injector for boiler-feeding.
I now proceed to describe with reference to the accompanying drawings the manner
in which my invention is carried out.
In Figure 1, W marks the inlet for the cold condensing water; E. S the inlet for
the exhaust steam; and D the outlet or point of discharge for the hot water
resulting from the admixture of the two. C is the metal casing enclosing the ports.
On entering the apparatus, the water passes first through the nozzle A, after
which it enters the first combining nozzle B, and becomes mixed with a portion
of the exhaust steam which enters at S, between the two nozzles. In traversing the
length of the combining cone B, the steam and water become intimately mixed and
issue from the outlet of B, in the form of a solid round unbroken jet, which then
enters the second cone B, and mixes with a second portion of steam with which it
thoroughly combines before reaching the outlet of the cone. From this it passes to
the third mixing nozzle B,, and so on through the whole series, the water as it passes
through each nozzle becoming more and more heated by its admixture with the hot
steam until it has attained the maximum temperature allowable, when it is discharged
as a solid jet of hot water at D.
By thus bringing together the water and steam at intervals the jet is not at any
point liable to distortion which would injuriously affect the working of the apparatus.
In this way the maximum useful effect is obtained from a given quantity of con-
densing water.
In Figure 2 is shewn a condenser arranged to be worked by overhead water, that
is, water supplied under pressure to the apparatus.
In certain circumstances it might happen that if the supply of water were shut off
from W before the engine to which the condenser is applied were stopped, that then
as there would still be a vacuum in the exhaust pipe of the engine, the water from
the hot-well into which the condenser discharges might be drawn up by the vacuum
and enter the cylinder while the engine was running, causing serious breakage and
damage. To prevent such an accident occurring I place in the water supply pipe and
close to the nozzle A an air-valve V which shall open whenever the water supply is
shut off and vacuum exists in the condenser.
By thus opening, air will be admitted into the condenser and exhaust pipe and will
prevent the rushing back of water from the discharge pipe D. In condensers worked
without overhead water a similar valve may be used on the discharge pipe.
In Figure 3 is shewn the exhaust steam suction nozzle N which is fitted into the
water nozzle A, and is intended to assist in starting the flow of water through A where
no head of water exists, as already before described.
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. In ejector condensers, the employment of any number of mixing nozzles or
combining cones of approximately similar size and shape and concentric with one
another, with the object of bringing the steam gradually and in successive portions
into combination with the water so that the mixture of the two becomes thorough and
complete, while at the same time the true cylindrical form of the jet is retained and
its surface only slightly disturbed, as hereinbefore described and illustrated in Fig. 1
of drawings.

page_text: 2. In ejector condensers worked by means of water under pressure, the arrange-
ment of an air-valve on the water pipe which shall open by suction and break the
vacuum when the water is shut off, substantially as described and shewn in Fig. 2 of
drawings. Or a similar valve fixed on the discharge pipe of the condenser with the
same object.
3. The employment of a central exhaust steam suction nozzle fixed in the water
nozzle substantially as and for the purpose herein before described and illustrated in
Fig. 3 of accompanying drawings.