IMPROVEMENTS IN CONDENSING APPARATUS FOR STEAM ENGINES, VACUUM PANS AND SIMILAR APPARATUS
Year: 1885

page_text: I, ARTHUR WILLIAM LOVELL REDDIE of the Office for Patents, 6 Bream's
Buildings, Chancery Lane in the County of Middlesex, Patent Agent do hereby
declare the nature of the invention for IMPROVEMENTS IN CONDENSING APPARATUS
FOR STEAM ENGINES, VACUUM PANS AND SIMILAR APPARATUS and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :—
This invention relates generally to those condensers which are used in connection
with steam engines, vacuum pans and other similar apparatus, in which it is
necessary or desirable to create and maintain a partial vacuum. The invention
relates more particularly however to that class of these condensers which are
known as "Injector" and "Ejector" condensers. The condensers of this class, as
heretofore constructed, have been found in practice capable of creating and
maintaining an effective and uniform vacuum only in those cases where the
injection or condensing water could be supplied under a considerable head, or could
be allowed to have a fall of at least thirty four feet, so as to acquire either by its
head or fall the necessary velocity to produce and maintain an effective vacuum.
This condition rendered these condensers unavailable except in those cases where
the condensing water could be supplied under a considerable natural head, or was
raised to a considerable height by pumping machinery especially provided for that
purpose, and in all cases its necessary elevation above the end of the discharge
pipe made the condenser a very bulky and cumbersome apparatus. Besides this,
to obtain the necessary velocity of the condensing water, very narrow and
constricted passages were employed, thus making the apparatus liable to frequent
stoppage and derangement. Another objection was due to the fact that a much
larger quantity of water was employed than was needed for condensation, thus
lowering the temperature of the hot well, and causing the injection of cool water
into the boiler.

page_text: It is the object of the present invention to overcome these difficulties and to
provide a condenser of this class which shall be capable of producing and main-
taining an effective and uniform vacuum without the necessity of having the
condensing water supplied under any head or fall but a short distance, and without
the necessity of using any more water than is necessary to condense the steam and
maintain the temperature due to the vacuum employed. To that end the invention
consists broadly in providing or combining a condenser of this character with a
duplex pump which is so arranged as to withdraw the mingled air and water from
the condenser as fast as it accumulates therein and thus maintain a uniform and
continuous current at a high velocity and without stoppage or interruption.
The invention also embraces various details of construction both in the condenser
proper and in the pump which is used in connection therewith, by which the
apparatus is made more compact in form, and its parts are rendered more accessible,
and by which a more rapid and perfect condensation is effected; all of which will
be hereinafter explained and particularly pointed out in connection with the
accompanying drawings; in which
Fig 1 is a side elevation of a condensing apparatus embodying the present
invention.
Fig. 2 is an end elevation of the same, looking from the left of Fig. 1 the upper
part of the condenser proper being omitted.
Fig. 3 is a horizontal section taken upon the line x x of Fig 1 showing the pump
in plan view.
Fig 4 is a horizontal section taken upon the line y y of Figs 1; 2, 5, 6.
Fig 5 is a sectional elevation taken upon the line xx of Figs 2, 3, 4 and 6.
Fig: 6 is a cross section taken upon the line vv of Figs 1 3, 4, and 5.
Fig 7 is a sectional elevation taken upon lines corresponding to the lines xv of
Fig 6 illustrating a modification which will be hereinafter explained.
Fig: 8 is a side elevation of the water cylinders and condensers proper,
illustrating another modification which will be hereinafter explained.
Fig. 9. is an end elevation of the same looking from the left of Fig. 8.
Fig. 10 is a sectional elevation of the same, taken upon the line x x of Figs 8
and 11, the induction and force valves, and also the upper part of the condenser
proper being omitted.
Fig: 11 is a similar view taken upon the line x x of Figs 9 and 10.
Fig 12 is an enlarged sectional view of one of the suction valves and its seat
and
Fig 13 is a plan view upon a like scale of the valve seat.
;
Referring to said drawings it will be seen that the condenser proper which has
been selected for illustration in the present case, is of substantially the same
general construction as that shown in United States Letters Patent N° 227,342,
granted to my Foreign Correspondents May 11th 1880. It consists essentially of a
vertical pipe 90, to the upper end of which is secured a connection 91 through
which the steam to be condensed is introduced from the exhaust of the engine, or
other source of supply. The upper side of the connection 91 is provided with an
opening 60 which communicates with a small chamber 92 into which the condensing
water is introduced through an opening 93 which communicates with a pipe leading
to the water supply, which may be from a head or from any source not more than
twenty five feet below the level of the opening 93. The water supply pipe will of
course be provided with the usual cock or valve for regulating the flow of the
water into the condenser. Extending downward through the opening 60 and for
some distance into the pipe 90 is a small pipe 89 which is provided at its lower
end with an enlarged foraminous nozzle 88. The nozzle 88 may be made integral
with the pipe 89 as shown, or it may be made detachable therefrom. The area of
the chamber 92 is somewhat greater than that of the opening 60, so that a narrow
shoulder or ledge 9 is formed at the bottom of the chamber upon which rests a
flange 8 formed upon the upper end of the pipe 89 and which serves to hold the
pipe in position. The top 94 of the chamber 92 is made removable, and the pipe 89

page_text: is provided with a bale or handle 95 which extends upward to near the top of the
chamber, so that by simply removing the cover 94 the pipe 89 can be readily
removed from and replaced in the pipe 90, without disturbing the other parts of
the apparatus. This is a feature of considerable importance, as when the condensing
water contains any dirt or sediment the openings in the nozzle 88 are liable to
become filled so as to arrest the flow of water, thus making it necessary to remove
the same for cleaning. In the construction shown in the letters patent referred to,
this removing of the pipe 89 and the nozzle for cleaning could only be effected by
breaking the connection between the condenser and the water supply pipe, which
was very inconvenient and troublesome.
The pipe 90 is gradually contracted from its upper to its lower end so that the
discharge opening 96 at its lower end is considerably reduced in size. This opening
is however of such area that when the condenser is in operation the outflow or
discharge of mingled air and water will not exceed the capacity of the discharge
opening. The pipe 97 is, as will be observed, considerably larger than the discharge
opening 96, so that as soon as the mingled water and air passing through th
condenser have passed the discharge opening, they will be allowed to flow rapidly
away so as to afford no obstruction to the current passing through the condenser.
The construction thus far described is, as already stated the same, except in the
particulars specified, as that shown and described in the letters patent before
referred to. Reference is therefore made to said letters patent for a more specific
description of this part of the apparatus, and also for directions as to the arrange-
ment and relative proportions of the different parts.
Where a condenser of this construction or of any of the constructions common
in this general class of condensers, is employed under such conditions that the
condensing water can be supplied under a considerable head, or that the tail pipe 97
or its equivalent pipe can be made of considerable length, say, about thirty four
feet, the velocity of the water due to the head or the fall of the water through
the pipe 90 and the tail pipe can be relied upon to form and maintain a sufficient
vacuum in the condenser to effect good results, but in many cases it is impossible
or at least very undesirable to comply with either of these conditions, and in such
cases it is necessary to provide means not only for withdrawing the mingled water
and air from the condenser, but also for preventing the air from passing upward
through the pipe 97 so as to destroy the vacuum. In order to make the condenser
most effective the vacuum must be maintained at a uniform tension, and to do this
the water and air must be withdrawn in a steady and uninterrupted stream so as to
produce a steady flow through the condenser.
It has been long a well recognized fact in the art, that the duplex pump by
reason of its peculiar action, is capable of discharging the water or other fluid
which it pumps in a more steady and uniform manner than any other known form
of pump not even excepting the rotary. It is therefore manifest that the duplex
pump is the most desirable form for use in connection with a condenser. In order
however to enable the duplex pump to operate successfully it is necessary that
the fluid upon which it operates should be of a uniform or practically uniform
density so that a uniform or practically uniform resistance will be offered to the
pistons or plungers throughout the entire stroke. This condition does not exist in
an ordinary condenser in which the water and air and uncondensed vapor are
allowed to separate before they are withdrawn from the condenser and consequently
all efforts to use the duplex pump in connection with this form of condenser have
proved unsuccessful. This was owing to the fact that the fluid upon which the
pump operated was not of uniform density, the pump being required to operate for
a portion of its stroke upon water, and then for the remainder of the stroke upon
air, thus causing the resistance offered to the pistons or plungers to vary during
different parts of the stroke and causing the pump to move spasmodically and in
such manner that the condenser was not properly evacuated.
It was not known, prior to this invention, that the conditions necessary to the
successful operation of the duplex pump could be obtained in any form of condenser,

page_text: but we have found that by the use of the "injector” or “ejector" condenser, and
particularly by the use of the condenser shown in the patent before referred to, the
condensing water and the water resulting from the condensation of the steam,
together with the uncondensed vapor and the air drawn into the condenser are
when delivered from the condenser so thoroughly commingled as to form a fluid of
a practically uniform density, or at least of a sufficiently uniform density to make
it practical to employ the duplex pump for evacuating the condenser.
The duplex pump shown in the present case is, as to its general construction, the
same as the well known Worthington Duplex pump. It consists of two steam
cylinders 50. 51 which receive steam from the boiler through the pipe 52, and are
provided with the well known connections 80, 81, by which the induction and
exhaust valve of each cylinder is operated from the piston rod of the other, and two
water cylinders 70, 71, which communicate with suction and force chambers 98, 99,
and the plungers of which are connected directly to the piston rods 75, 76, of the
steam cylinders. The construction and operation of this class of pumps is so well
understood by those familiar with the art, that no further description of its
features, except those which are novel is considered necessary in the present case.
The tail pipe 97 may open into or communicate directly with the suction
chamber 98 of the pump, when said chamber is located in any of the positions in
which it is commonly placed in this class of pumps, but for the sake of economy in
the construction and to secure compactness in the apparatus the suction chamber
will preferably be arranged as shown in Figs 1 to 7 inclusive, as this construction
will permit the condenser proper to be located directly above the pump, and the
tail pipe 97 to pass directly downward through the force chamber and be entirely
enclosed within the pump casing. In this construction both of the water cylinders
and the suction and force chambers are enclosed within a single shell or casing, the
water cylinders 70 71 being located at the bottom, the force chamber 99 at the top,
while the suction chamber 98 is located directly above the water cylinders and
beneath the force chamber. The pipe 90 is mounted upon the top of the casing
enclosing these parts, and the tail pipe 97 passes downward through the force
chamber and opens into the top of the suction chamber in close proximity to the
suction valves. The space between the suction and force chambers is divided into
four compartments by partitions 74, and these compartments form chambers for
the suction valves 72 which open upward upon the upper side of the suction
chamber. The chambers containing the suction valves are provided at their ends
with passages 73 which open downward past the ends of the suction chamber into
the opposite ends of the water cylinders. The force valves 69 are located on the
bottom of the force chamber and control openings which communicate with the
four chambers in which the suction valves are located. The force chamber is
provided with the usual connection 86 to which the discharge pipe 87 is attached,
and both the force chamber and the chambers for the suction valves are provided
with suitable hand holes, as 85, through which access can be had to the valves.
The suction and force valves may be of any approved construction but will
preferably be of the form shown in Fig. 12. The valve seats 68 will also be
preferably of the form shown in Fig 13 and will be arranged to project a short
distance above the surrounding surface so that sediment will be prevented from
accumulating beneath the valves.
The operation of the condensing apparatus just described is as follows: Steam
being admitted to the cylinders 50, 51 so as to set the pump in motion a vacuum
will be formed in the condenser, engine, and water supply pipe, which will cause
the condensing water to flow in through the pipe 89 and nozzle 88 into the pipe 90.
The engine being then started the exhaust steam will enter through the con-
nection 91 above the spray from the nozzle 88 and coming into contact with the
water will be rapidly condensed The velocity of the steam entering the condenser
will be communicated to the water which also enters at a velocity due to the draft
of the vacuum so that the whole will pass downward through the pipe 90 and into
the pipe 97 and chamber 98 at a high velocity carrying with it in a thoroughly

page_text: commingled condition all the air or uncondensed vapor which enters the condenser
with the steam The commingled air and water which thus enters the chamber 98
will be withdrawn by the pump and discharged into the force chamber 99 before
its velocity is entirely checked or sufficient time or space allowed for separation.
From the force chamber 99 the water may be allowed to flow through the pipe 87
to a hot-well, or it may be delivered into a tank at any desired height above
the pump.
The duplex pump by reason of its peculiar action causes the mingled air and
water to be withdrawn from the chamber 98 in a continuous and uninterrupted
stream, thereby preventing it from rising and falling in the pipe 97 so as to check
or vary the current passing through the pipe 90. This is a fact of great importance
as the effectiveness of the vacuum depends upon its being maintained at a uniform
tension, which uniformity of tension can only be maintained by a steady withdrawal
of the air and water. It is also to be remarked that the momentum of the mingled
air and water as it passes through the condenser is utilized in aiding the pump (it
having been demonstrated in practice that with a vacuum of twenty eight inches
in the condenser and the water supply convenient, the pump can be made to work
against a resistance from the atmosphere of only about six inches) This action is
directly the reverse of that of the ordinary air pump and condenser, in which the
air and water are allowed to separate before being delivered to the pump. To
evacuate the condenser in such case the pump must maintain a vacuum of greater
tension than that in the condenser and upon a larger space in order to entrap the
attenuated air and cause it to flow from the condenser to the pump.
At the same
time the pump must work against a resistance equal to the full vacuum attained.
In the apparatus just described only about three per cent more space is required
in the pump cylinders to discharge the mingled air and water than would be
required to discharge simply the condensing water. With the apparatus just
described the commingling of the air and water is so perfectly effected as to give
the pump a perfectly smooth and even action, thereby permitting the water to be
delivered at any height without impairing the effectiveness of the condenser. This
is a feature of great importance in many cases where it is desired to force the water
into an elevated reservoir for further use, as it avoids the necessity of providing a
special pump for that purpose.
It will be observed that in the construction shown in Figs 1 to 6 inclusive, the
condenser proper is placed entirely above the pump casing, the tail pipe 97 alone
being within the casing. If it should be desired to make the apparatus still more
compact the lower end of the pipe 90 may be made to extend downward into the
pipe 97 as shown in Fig. 7 and by this means the height of the apparatus may be
considerably reduced without affecting its efficiency.
If for any reason it should be desired to locate the suction chamber below the
water cylinders it may be done as shown in Figs 8 to 11 inclusive, the pipe 90 being
arranged to pass downward either between the two water cylinders, or at one end
of them. If the pipe 90 is located at the end of the water cylinder the tail pipe 97
may be arranged horizontally and form an extension of the suction chamber as
shown in Figs 8 to 11. The two water cylinders may be provided with a single
force chamber into which both discharge their water, or they may be provided
with separate force chambers which communicate with a common outlet as shown,
or in fact the water end of the pump may be constructed in any of the ways
common in this class of pumps. It is also to be understood that the construction
of the steam end of the pump may be varied within wide limits without departing
from the invention. Each side instead of consisting of a single cylinder may
consist of compound cylinders, or in fact the steam end of the pump may be con-
structed and arranged in any of the well known ways so long as the duplex
principle is preserved.
In conclusion it is also to be remarked that the condenser proper may be of a
different construction from that shown without departing from the invention The
form shown has been selected for the purpose of illustration because all things

page_text: considered it is regarded as the best form known for use in this combination, but
any of the other well known forms of injector or ejector condensers may bé
substituted without departing from the essential feature of the invention.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my Foreign Correspondents, I declare that what I claim is
1. A condensing apparatus for steam engines, vacuum pans and similar apparatus,
consisting of a duplex pump and an "injector" or ejector" condenser, the two
being combined and arranged to co-operate, substantially as described.
2. A condensing apparatus for steam engines, vacuum pans and similar apparatus,
consisting of the duplex pump, and an "injector" or "ejector" condenser which is
arranged to communicate directly with the suction chamber of the pump substan-
tially as described.
3. A condensing apparatus consisting of the duplex pump, the enlarged tail
pipe 97, communicating directly with the suction chamber of the pump, the pipe 90,
and the nozzle 88 substantially as described.
4. A condensing apparatus consisting of the duplex pump, the enlarged tail
pipe 97 enclosed within the pump casing and opening into the suction chamber,
the pipe 90, and the nozzle 88, substantially as described.
5. The combination with the pipe 90, of the chamber 92 having the removable
cover 94, and the pipe 89 having the nozzle 88 and bale 95 substantially as
described.