IMPROVE- MENTS IN SURFACE CONDENSERS. AND IN EVAPORATORS AND HEATERS PROVISIONAL
Year: 1853

page_text: LETTERS PATENT to Moses Poole, of the Avenue Road, Regent's
Park, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN SURFACE CONDENSERS. AND IN EVAPORATORS AND HEATERS
PROVISIONAL SPECIFICATION left by the said Moses Poole at
the Office of the Commissioners of Patents, with his Petition, on
the 18th November 1853.
I, MOSES POOLE, of the Avenue Road, Regent's Park, in the
County of Middlesex, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN SURFACE CONDENSERS, AND IN EVAPORATORS
AND HEATERS FOR STEAM ENGINES," to be as follows:-
The first improvements is in the method of securing the tubes of
a tubular condenser to a tube sheet in such manner that the tubes
are free to expand and contract, and can easily be withdrawn and
replaced, while the joint between the exterior of the tubes and the
holes in the tube sheet is kept perfectly tight, preventing the passage
either of water or steam from one side of said tube sheet to the other.
The whole of these purposes being effected by what I denominate
a supplementary elastic tube sheet, made of vulcanized india-rubber,
A

page_text: or gutta-percha, or their equivalents, and its accessories. To apply
this sheet I proceed as follows:-First, I bore the holes in the
usual metallic tube sheet a little larger in diameter than the out-
side of the tubes; next I place the tubes through both tube sheets,
with their ends projecting a short distance beyond each of them. I
then procure a sheet of vulcanized india-rubber, and pierce it with
holes, smaller in diameter than the outside of the tubes; and equal in
number and corresponding in position to the holes in the metallic sheet.
When two such sheets are finished I enter each tube in its appropriate
holes in the elastic sheet, and force said sheet down over the tubes,
until it rests against the metallic tube sheet. The india-rubber will
then form a very short cylinder around each tube, hugging it closely,
and preventing any fluid from passing between the india-rubber and
the tube. The elastic supplementary tube sheet is equal in arca, or
nearly so, to the metallic tube sheet, and its edges are held tight down
upon the former by means of a species of metallic ring, which may be
kept in place by screws passing through it, and through the india-
rubber into the metallic tube sheet. These supplementary elastic tube
sheets must always be placed on that side of the metallic sheet which
is nearest the water and furthest from the steam, according as the
steam to be condensed is admitted among the tubes and outside of
them, or is permitted to pass inside of the tubes while the water is
on the outside of them. The water will then by its pressure hold the
clastic sheet tight around the tubes. To prevent the tubes from creep-
ing out of the tube sheets I. apply gratings, the holes in which are so
small that the tubes cannot pass through them; one of these gratings
being properly secured over each of the ends of the tubes, and at a
little distance therefrom. The gratings and the rings are the accessories
to the elastic tube sheet.
My second improvement consists in applying an additional injection
pipe to that form of surface condenser in which the condensing water
passes through the tubes, the said pipe being so arranged that when a
cock in it is opened it discharges water among the tubes, and out-
side of them. When the inside of my condenser becomes deranged
through leakage of the tubes or otherwise, I shut off the water flowing

page_text: through the. tubes, and open the additional injection; my surface con-
When I use that form
denser is then converted into a jet condenser.
of surface condenser in which the steam passes through the tubes, and
the condensing water is admitted outside of them, I apply a secondary
steam pipe, so arranged that by opening a cock or its equivalent I
can admit the exhaust or escape steam among the outsides of the
tubes. By opening this pipe I can convert this form of surface con-
denser into a jet condenser.
My third improvement consists in a method of evaporating or
distilling fresh water from salt water by the use of a portion of
the exhaust steam; the said water is to be fed into the boilers, or
otherwise used as convenience may dictate. For this purpose I take
a vessel whose interior is divided into compartments, either by the
use of tubes or otherwise, and I connect one compartment, by means
of a pipe or otherwise with a condenser: The other compartment
is by means of a pipe connected with the exhaust pipe of the
steam engine, and is furnished with means of drawing off the water
that may accumulate in it; both compartments should be steam-
tight. The pipe which leads from the second compartment to the
exhaust pipe is provided with a valve, either- self-acting or moved by
the engine, the said valve being located between the exhaust nozzles
and the condenser. Between the valve and the condenser is placed
another valve, so arranged that it will close the exhaust pipe, and cut
off all communication between the cylinder and the condenser. This
latter valve receives from the engine such a motion that it is open and
shut twice during each revolution of said engine. The operation of
these parts is as follows:-The first compartment is partially filled with
salt or impure water, then the engine being in motion, and at or near
the end of its stroke, the exhaust valve opens, and steam enters the
exhaust pipe; at this time, however, the last-mentioned valve is shut,
and the exhaust steam lifts the exhaust valve, if it be self-acting, and
passes into the second compartment; when the piston has moved a few
inches more or less, say one tenth or thereabouts of its whole stroke,
the last-mentioned valve is opened and the other shuts, and, the re-
The
mainder of the cylinder full of steam passes into the condenser. .
A 2

page_text: steam which has passed into second compartment heats the water
contained in the first compartment, and becomes cooled and finally
condensed; but the second compartment receives a fresh charge at each
stroke of the engine, so that it finally heats the water in the first com-
partment to such an extent that it commences to make steam, and this
steam passing through the passage before described goes into the con-
denser, and is there condensed along with the exhaust steam from the
engine. When the second compartment gets too full of water from
the condensation of steam therein, the water is removed by a self-acting
apparatus, or by one put in motion by an attendant. This evaporator
will be of great use only in those instances where a surface condenser
is employed.
My fourth improvement consists in a method of heating the feed
water by means of a portion of the exhaust steam, and for this purpose
I use an apparatus similar in all respects to that described for evapo-
rating, except that the first compartment is supplied with water
continuously by means of the feed pump, and is connected with the
boiler by an open passage instead of the condenser.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Moses Poole in the Great Seal Patent Office
on the 11th May 1854.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
MOSES POOLE, of the Avenue Road, Regent's Park, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of November, in the
year of our Lord One thousand eight hundred and fifty-three, in the
seventeenth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Moses Poole, Her special
licence that I, the said Moses Poole, my executors, administrators,
and assigns, or such others as I, the said Moses Poole, my executors,
administrators, and assigns, should at any time agree with, and no

page_text: .
others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain; and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN SURFACE CONDENSERS, AND IN EVAPORATORS AND HEATERS FOR STEAM
ENGINES," (communicated to me by a foreigner residing abroad,) upon
the condition (amongst others) that I, the said Moses Poole, by an instru-
ment in writing under my hand and seal, should particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be, filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Moses Poole, do hereby declare
the nature of the said Invention, and in what manner the same is to
be performed, to be particularly described and asctained in and by
the following statement thereof (that is to say): .
The improvements in steam engines (communicated to me) have one
common end, namely, economy of fuel, and may be divided under three
general heads; first, improvements in the condenser proper; second,
improvements in the method of evaporating fresh from salt or impure
water in order to supply leakages; and, third, improvements in heating
the feed water Under these three heads there are several features of
invention, all necessary in perfecting the whole; and as these latter are
not easily desirable by words only I have accompanied this Specifi-
cation by appropriate Drawings.
In the Drawings Figure 1 is a side view of the condenser, eva-
porator, and heater, with some of their accessories; Figure 2 is an
end view of the same, with a bonnet removed from the head of the
evaporator, and one half of the condenser head cut away; Figure 3
is a side view of the condenser, with the upper half represented as
in section; Figure 4 is a section through the evaporator and heater;
and Figure 5 is a sectional view on a large scale of the condenser
tubes, auxiliary or supplementary elastic tube sheet, confining plate, &c.
The same letters refer to the same parts in all the Figures.
My improvements in condensers relate solely to that species thereof

page_text: known to engineers as a surface condenser, and the advantages
attending the employment of a good condenser of that class in engines
whose boilers are supplied with salt or impure water are so well
known to engineers that they need no special setting forth in this
paper. The difficulties attending the successful practical working of
such condensers are likewise well known, and may be comprised under
two great heads; first, their liability to leakage at the junction of the
tubes with the tube sheet; and, secondly, the impossibility of repairing
or otherwise rendering serviceable a leaky, and consequently choked,
condenser, while the engine is in motion; the want of a serviceable,
economical, and easily managed evaporator is another drawback to the
employment of such condensers, and a heater which would without
material. waste of steam heat the feed water up to the boiling point, or
nearly so, would render the whole apparatus more economical in the
saving of fuel, and would certainly not impair the efficiency of surface
condensers and evaporators in so far as they tend to the saving of wear
of boilers. Tubes of surface condensers have hitherto, as a general
rule, been secured in the tube sheets firmly, and the difference of
expansion and contraction between different tubes or between the
whole mass thereof, and the shells or cases in which they are enclosed,
and to which the tube sheets are attached, has caused a constant strain
upon the points of attachment of the tubes; this strain soon causes
leakage. As there is a difference of pressure from thirteen to fourteen
pounds between the outer and inner surfaces of the tubes, small
apertures will discharge large quantities of water, and the steam space
in the condenser will become, in a measure, choked up. The efficiency
of the condenser is thus destroyed. The attaching of these tubes
properly is moreover a slow and costly operation, and the condenser as
a whole is expensive. The Invention obviates both of these evils, and
moreover renders the condenser serviceable even if leaky to such an
extent as would wholly disarrange the action of any surface condenser
*built проп usual plans.
The nature of the first part. of the Invention, therefore, consists
in a method contining the tubes or their equivalents of a surface
condenser in their tube sheets by means of a supplementary or

page_text: auxiliary tube sheet of vulcanized india-rubber or gutta-percha; or
it or their equivalents for: that purpose, applied substantially in the
manner herein-after described, whereby the joints between the exterior
of such tubes and their tube sheet is preserved air and water tight, or
nearly so, while cach tube is free to expand and contract, or slide to
and fro in the tube sheets as aforesaid.
".
And the nature of the second part of the Invention consists in pre-
venting such tubes, so secured from creeping out of their seats while
free access of steam or water is permitted to their interiors, substantially
as herein-after specified.
The nature of the third part of the Invention consists in constructing
the guard above alluded to in such manner that it will also perform the
duty of confining down the edges of the supplementary tube sheet, as
herein described.
The nature of the fourth part of the Invention consists in combining
with a surface condenser whose steam space is outside of the tubes a
secondary or supplementary injection pipé, or its equivalent, so arranged
as to distribute water over the, outside of the tubes,. whereby the con-
deuser may be used as an ordinary jet condenser in the event of any
unforseen injury to the tubes or tube sheet, or the joints between them..
The nature of the fifth part of the Invention consists in evaporating
fresh from salt or pure from impure water by means of exhaust steam
obtained substantially in the manner herein-after described, and con-
densed in the compartment of the evaporator to which it is admitted
by cold derived from the water which is being evaporated, substantially
as specified herein.
The nature of the sixth part of the Invention consists in imparting
additional heat to feed water in its passage to boilers by means of steam
obtained and condensed as is set forth under the fifth head of Invention,
said steam being applied either directly in contact with the feed water
to be heated or in a compartment distinct therefrom.
And the nature of the last part of the Invention consists in providing
an evaporator, substantially such as is herein described, with a brine
pump, and in arranging the induction orifice thereof in the manner and
for the purposes herein specified.

page_text: "
The Drawings exhibit a condenser in which water is passed, forced,
or drawn through tubes, while steam is admitted outside thereof, such
form of condenser being, in my opinion, preferable to that more usual
one in which the water is outside and the steam inside of the tubes.
The Invention, however, excepting the third and fourth heads
thereof, is equally applicable in condensers of the more usual arrange-
ment, and the plan of heating the feed water is applicable even where
surface condensers are not used, and also in non-condensing engines.
In the Drawings a somewhat unusual form of condenser shell is
exhibited, and likewise certain peculiar relative arrangements of parts;
such form is, however, a non-essential, as the Invention is not depen-
dent upon precision of form, and the arrangements are essential only
in so far as they are necessary to produce the described effects, all
arrangements producing such effects being equivalents of those repre-
sented. The shell of the condenser is represented at a, a, the induction
entrance for condensing water is shown at b, b, and this water, after
producing its effect, passes or is forced out at c, c, having in its passage
flowed through the bores of the tubes. These tubes d, d, are passed
through orifices properly arranged in the tube sheets e, e, which latter
are secured in any appropriate manner. The tubes are of such length
that each end thereof projects beyond the plane of each tube sheet, and
each orifice is sufficient in size to admit of the free passage of a tube;
air, water, or vapour might, therefore, if no other provision was made,
pass freely around each tube from one side of the tube sheet to the
other. In order to prevent such passage, and render tight the joint
between the exterior of each tube and the interior cylindrical surface of
each orifice, I procure a sheet of vulcanized india-rubber or its equi-
valent, similar in contour to the metallic tube sheets, and nearly equal
in area. This supplementary clastic tube sheet is then pierced with
holes corresponding in number and position with those in the metallic
tube sheet; these holes being, however, smaller in diameter than the
exterior diameters of the tubes; such difference in size depending partly
apon the thickness of the elastic sheet as proportioned to the size of the
tubes, and partly upon the fancy of the constructor. This supplemen-
tary tube sheet is then applied over the ends of the tubes, and each

page_text: hole therein is forced over the exterior and ends of each tube until the
general plane of one side of the supplementary tube sheet coincides, or
nearly so, with the general planc of one side of the metallic tube sheet.
The supplementary sheet ff, will then grasp or hug each tube, forming
around it a species of short cylinder or truncated cone, as clearly shown
at gg, in the Drawings. This cone or cylinder will be longer or
shorter, depending upon the thickness of the supplementary sheet, and
the relative size of the apertures therein, as compared with the exterior
diameter of the tubes, and will, if the elastic sheets be thick, and the
comparative size of the holes therein large, almost disappear, shewing
The best result,
a mere bulge beyond the general plane of the sheet.
however, will not be attained when the proportions are carried to such
an extreme, and a truncated cone of such proportional size and shape
as is shewn in the large scale view in Figure 5 will serve best in prac-
tice. Now it will be evident from this description and inspection of the
Drawings that the joint between the supplementary sheet and the
exterior of each tube will be perfectly tight, and that the truncated
cone will hug the tube more and more closely as the pressure upon
said sheet and cone increases. The condensing water might, however,
pass in under the edges of the supplementary sheet, thence between it
and the metallic sheet, and finally between the orifices therein and the
tubes which they surround into the steam space of the condenser. To
prevent this one or more rings h, h, are firmly held down upon the
edges, and, if desired, over certain parts of the surface of the elastic
tube sheet, compressing it tightly against the metallic sheet, and thus
effectually preventing any leakage. Two such sheets of india-rubber
must usually be employed, one at each end of the tubes, and each pro-
vided with proper confining rings; but some may prefer to use one
elastic sheet only, confining one end of each tube in a metallic tube
sheet in any usual manner. The tubes will even then have ample
scope for expansion and contraction, and the condenser will remain
tight; but this method will be more costly than if the method of
securing the tubes by means of an elastic tube sheet was employed at
each end. When the elastic tube sheet is applied at each end, the
further advantage results that the tubes may be removed easily for the

page_text: purpose of cleaning, or in order to substitute new for worn out tubes;
but as the tubes are free to expand, contract,. and creep. in either direc-
tion, they might after a time creep entirely out of their seats in one or
the other of the metallic tube sheets. In order to prevent such an
occurrence gratings or pierced sheets, or a series of rods j, j, are sup-
ported and secured parallel or nearly so to the plane of the tube sheets,
and just touching the ends of the tubes, or, as I prefer, at a short distance
therefrom. If the ends of the tubes touch this grating, and one should
chance to expand a little more than its neighbours, or to a greater degree
than the shell, it can compensate itself by bending slightly, which will
not cause any leak, but when the grating, does not touch the tube ends
any tube may creep until it touches one grating or the other, and will
then have its progress stopped. Condensing water can pass through
the openings in a grating or between bars if they are employed, but I
prefer to use metallic sheets jj, pierced with holes k, k, corresponding
in number and position with the tubes, and each a little smaller in
diameter than the exterior of the tube to which it is opposite. For
the sake of economy and convenience I construct the sheets j, j, in one
piece with the rings h, h, so that one series of fastening serves for both.
As the metallic sheets are not supported by the tubes they might, unless
enormously heavy, fracture under pressure; lugs 1, are therefore
formed upon these sheets, and into them by means of right and left
handed screws are secured rods m, m, which act as stay bolts. These
rods are located in spaces where rows of tubes are left out, and these
spaces serve as free passages for steam which can thus easily seek the
colder parts of the condenser, thereby tending to equalize the tempera-
ture, and rendering the whole condensing surface effective. Exhaust
steam is admitted to the condenser through the nozzle n, on to which
the exhaust pipe is connected, circulates among the tubes, and is con-
densed upon their cold surfaces, and is drawn off in the shape of water
by any ordinary air pump whose induction passage is connected with the
nozzle o, condensing water being admitted and discharged through the
nozzles b, b, and c, c. In case of any accident causing such leakage
around the tubes or through them or their tube sheets as would choke
or partially choke the condenser, the flow of water through nozzles b, b,

page_text: and c, c, may be partially or wholly checked by means of valves or other-
wise, and a stop valve located upon the nozzle p may be opened. This
latter nozzle is connected with an, ordinary injection pipe, and when the
stop valve is opened water will enter among the tubes through the
orifices q, q. This impure or salt injection water will mingle with and
condense the steam, and both the condensing and condensed water will
be drawn off by the air pump connected at o, which will ordinarily be
of sufficient capacity to effect that purpose. The simple shutting off of
the flow of water through the tubes, and opening of a stop valve
between the injection pipe and nozzle p, will therefore convert a surface
into an ordinary jet condenser. The absolute efficiency of the engine
will therefore be unimpaired in the event of the failure of the surface
condenser on account of leaks therein. As boilers and joints will leak
despite all attainable perfection of workmanship, and as steam must at
times escape through safety valves, the water level in boilers supplied
solely with water condensed from the steam that passes through the
engine must of necessity lower, and to ensure perfection of action
additional supply of pure water must be furnished. This necessity has
been recognized by other contrivers of surface condensers, who have
adopted various plans to suit the emergency. Among these are several
plans on the same principle, and all purposing to evaporate water by
means of heat derived from a portion or the whole of the exhaust
steam on its way to the condenser. Such schemes have failed in
practice for three principal reasons: first, because the steam passes to
the condenser in a current, and has not time to part with its heat;
second, because the steam expands rapidly, loses its tension, and strives
instead of imparting to absorb caloric; and, third, because its pressure,
and consequently its temperature, are shortly after the opening of the
exhaust valve reduced nearly to the temperature and pressure existing
in the condenser, and this temperature is insufficient to evaporate any
quantity of water even in vacuo. After some thought and experiment
.I have discovered that these difficulties may be remedied by taking a
part of the exhaust steam on its way to the condenser, and while the
communication therewith is closed, and causing it to pass into an
evaporator where it is condensed by cold derived from the water which
it heats and evaporates. Many plans for causing such a flow of steam

page_text: from the cylinder just before the end of one stroke, or at the com-
mencement of another, have occured to me, all of which are identical
in principle, and one of which I will proceed to describe specially.
In the exhaust pipe between the exhaust valve (or the exhaust ports
when a single slide valve is employed) and the condenser is located
a supplementary exhaust valve, which through a motion derived from
some moving part of the engine is kept open during nearly the whole
of each stroke or half revolution, and is closed for an instant just as
the exhaust valve opens and is then opened again. The main exhaust
valves may be opened when each stroke is completed, or they may
have lead so as to open just before that time; or, if a single slide is
used, its moment of travel and lap may be so regulated as to pro-
duce the same effect; but in either case the supplementary exhaust
valve is shut just at the time that the exhaust valve is opened, or when
a slide valve has commenced to uncover the exhaust port; the exhaust
pipe between the main valves and the supplementary valve will there-
fore be filled with exhaust steam at the same temperature and pressure
as that just leaving the engine cylinder, and ceasing to act upon the
piston. From the main exhaust pipe a supplementary exhaust pipe
extends to one compartment of an evaporator whose other compart-
ment contains impure or salt water, and in this pipe is located a clack,
or puppet, or check valve, opening towards the evaporator. When steam
under a certain definite tension enters the main exhaust pipe at the
time that the supplementary exhaust valve is closed, it will lift the
clack or other valve in the supplementary exhaust pipe, and flow into
the evaporator; but when the supplementary exhaust valve is opened the
steam passes on to the condenser, and the valve in the supplementary
exhaust pipe closes, shutting a portion of the exhaust steam in the
evaporator. This portion of steam will heat the water in the evaporator,
and will in time be condensed therein, but the evaporator will at each
stroke receive a new charge, whose quantity will depend upon the
amount that the tension of the steam therein has decreased when com-
pared with the tension of the steam just passing out of the cylinder.
In the form of apparatus exhibited in the Drawings the portion of
exhaust steam enters the evaporator through the passage r, which is
connected in any appropriate manner with the supplementary exhaust

page_text: pipe, which, to avoid complication and as susceptible of description
without lineal representation, is not shown in the Drawings. The
supplementary exhaust valve, and the clack or other valve in the sup-
plementary exhaust pipe, are for the same reasons not represented; and
the same is the case with the apparatus for giving motion to the former,
which may be arranged by any competent engineer to suit any given
form of engine. When the portion of exhaust steam enters at r, it
passes through a series of tubes s, s, s, and imparts heat to the water
in the evaporator t, which surrounds them, being partially condensed
by thus parting with its heat. The water contained in t is supplied
through a pipe u, connecting with the discharge nozzle c of the main
condenser, and the amount of flow of said water is governed by a cock
v. The surface of the water in the evaporator is, by means of the
pipe w, connected with the vacuous space in the condenser to which
the evaporated water flows, and in which it is condensed along with
the exhaust steam from the main engine. Water is thus evaporated
in vaccuo, and when condensed drawn off by the air pump. The partial
vaccuum in t will cause water to ascend through u, and the water in t,
surrounding the tubes s, s, s, would in time become highly charged
with salt or other impurities, which would after a time deposit upon
the tubes and check the action of the evaporator. In order to prevent
such a state of affairs there is connected with the evaporator another
pipe a, whose opening is level, or nearly so, with the surface of the
water therein, and whose other end connects with a small pump y, to
which it is the induction pipe. This pump is actuated continuously by
the engine, and discharges such quantities of brine or nearly saturated
water as it may receive through an eduction pipe into the discharging
nozzle c. The pipe must in practice connect with the discharging
nozzle c at some point between the condenser proper and the connec-
tion of the pipe, with the same nozzle; the former pipe will then
supply the evaporator with water as pure as that which enters the con-
denser. As the pump y acts continuously and like an air pump, in so
far as it derives its supply from water in vacuo, the amount which it
will discharge will in a great measure depend upon the height of water
in the evaporator above the lower edge of the mouth of pipe a, and this
height will be governed partially by the amount evaporated, and par-

page_text: tially by the quantity of water furnished through u. If the water in the
evaporator should therefore at any time become too highly charged
with salts, it is only necessary to open wider; but if this water never
reaches the point of saturation, may be partially closed, as it is neces-
sary to prevent deposits in t, but is unnecessary to heat more water
than is absolutely required in order to avoid deposits. If no heater is
connected with the evaporator the induction pipe of a feed pump may
be connected with the bonnet into which the steani passes after flowing
through the tubes 8, s, s; all condensed steam may thereby be removed
and used as feed or otherwise; but when a heater is connected with
the evaporator, other means for drawing off the condensed steam, pre-
sently to be explained, may be employed. The distinctive feature of
the evaporator is therefore the condensing of a portion of exhaust steam
therein by means of cold derived from the water which is being evapo-
rated when said exhaust steam is applied substantially in the manner
lierein described; and it is clear that the position of the mouth of the
induction pipe of the brine pump at the level of the water in the eva-
porator is an important feature, as the density of the water in the
evaporator may then be governed by regulating the amount of supply.
In order that the density of the water in t may be observed readily, I
attach thereto a glass tube B, similar to an ordinary glass water guage,
and in it I locate a hydrometer or salinometer, whose indications are
visible through the glass. Surface condensers, it is well known, with a
given temperature of discharge. will usually furnish a better vacuum
than jet condensers, and this vacuum may be bettered by increasing
the supply of condensing water. As this water is in surface condensers
moved against friction only, and is not lifted out against the pressure of
the atmosphere as in jet condensers, a greater supply may be afforded
at comparatively little expense of power. The lowering of the tempera-
ture of the feed would be the only drawback to the effective power
afforded by an improved vacuum, and a good heater would fully com-
pensate for this deficiency. The heater which will serve this purpose,
and also prove serviceable in jet condenser or non-condensing engines,
is supplied with hot steam in the same manner as is the evaporator
just described, and this steam is condensed therein, the supply being
furnished through. an open passage connecting with the steam compart-

page_text: ment of the evaporator, or by means of an independent supplementary
exhaust pipe 'supplied with a valve, and connected to the main exhaust
pipe in a similar manner to that supplementary exhaust pipe which
supplies the evaporator. The former and less costly arrangement is
represented in the Drawings, and will now be described.
A. tube C is connected with the delivery passage of an air pump, or
with the discharge pipe of a feed pump, and by means of either or any
equivalent apparatus water is discharged upon the perforated dishes
D, D, D, or some equivalent therefor, and falls in a shower through the
orifices therein and over the edges thereof into the cavity F; as the
shower descends it is met by and mingles with a supply of steam
derived from the exhaust, as before described, which enters through a
passage G. This steam parts with its heat to the shower of water and is
condensed thereby, wholly or partially, while new supplies are furnished
at each stroke of the engine, and both feed water and condensed
steam, the whole highly heated, are drawn off through the pipe E by
means of an ordinary feed pump, and from thence supplied to the boiler.
The steam condensed in the tubes 8, s, s, of the evaporator flows as it
condenses through a small orifice H in the bottom thereof. into the
heater, and is drawn off with the water in the heater through E. The
mingling of the steam with a shower of water is perhaps the most
successful method of heating the latter, but the water may, without
departing from the principles of the Invention, be contained in a sepa-
rate compartment, so that the water and steam will be separated as
they are in the evaporator. If desired, a small valve opening towards
the heater may be secured upon the end of the passage G; if then the
tension of steam in the evaporator should fall below that in the heater
this valve will close, and the tension of steam in the heater, after the
supplementary exhaust valve is opened, will depend solely upon the
amount of condensation in the heater.
Now I wish it distinctly understood that precise forms and arrange-
iments of parts relative or otherwise, except that of the induction pipe
aperture of the brine pump, are not material to the successful working
of the Invention, and also that precise kinds of material or specific
forms of pipes, pumps, or valves are not essential, as any usual forms,
plans, or materials may be employed, so long as the. purposes herein

page_text: described are effected substantially in the manner set forth. The
supplementary elastic tube sheets may moreover be used in condensers
where the steam passes through the tubes and the water flows outside
thereof; the only change necessary being to place the supplementary
sheet on that side of the metallic sheet which is nearest to the con-
densing water. The elastic sheet may moreover be divided into many
pieces as convenience may dictate, so long as the edges of each sheet
are suitably held down. And I sometimes intend to distribute the
entering condensing water by means of several passages, so that an
equal flow may be secured to each tube. I further intend, on some
occasions, to insert with the bore of each tube a rod, properly sup-
ported, which will cause the condensing water to flow through them in
an annulus or ring, instead of in a solid cylinder. A valve or valves
worked automatically, and located between the ordinary exhaust valves
and the cylinder, or between the exhaust port and the cylinder, and
opening into the passages which lead to the heater and evaporator, or
either of them, will, if opened just before the ordinary exhaust valves
open, supply a portion of steam to said heater and evaporator; such
valve must be shut when the ordinary exhaust valve opens. Other
arrangements of valves than those described will also cause a
portion of
the exhaust steam to enter the heater or evaporator, or both of thein,
but they will be more equivalent of those described so long as said
portions of exhaust steam are delivered under some perceptible tension,
and do not pass into the condenser, but are condensed in the vessels
where they heat or evaporate, as the case may be.
Pierced nozzles, or drip plates, or any ordinary device for breaking
up water into particles, may be substituted for the dishes D, D, and
either the condenser, the heater, or the evaporator may be employed
separately or in connection with other known forms of condensers,
heaters, and evaporators, but the best effect will be produced when all
are employed together.
Having thus described the apparatus, I claim, first, the method of
securing or confining the tubes of a surface condenser in their tube
sheets, and of packing the joints between the peripheries of said tubes
and the sheet by means of a supplementary elastic tube sheet constructed
and applied substantially in the manner herein described.

page_text: Second, I claim a grating, or its equivalents, applied essentially as
herein described, whereby the tubes are prevented from creeping out of
their seats.
Third, I claim constructing the grating or its equivalent in such
manner that it shall also serve the purpose of securing the edges of
the elastic tube sheets.
Fourth, I claim combining a supplementary or secondary injection
pipe with a surface condenser whose steam space is outside of the tubes
thereof, substantially in the manner and for the purposes herein specified.
Fifth, I claim evaporating pure from impure or fresh from salt water
by means of exhaust steam obtained substantially in the manner herein
specified, when such steam is condensed in the compartments of the
evaporator, into which it is admitted by cold derived from the water
being evaporated, and is not permitted to pass into the main condenser.
Sixth, I claim imparting additional heat to feed water substantially in
the manner herein specified by means of steam procured substantially as
described herein, and condensed by cold derived from the water which
it heats; and this I claim whether said steam and water are mingled
or are contained in distinct chambers as specified and set forth herein.
And, lastly, I claim providing an evaporator heated by steam, as
described, with a brine pump, whose induction pipe has an aperture
located in the evaporator substantially in the position described,
whereby certain results, as herein set forth, are attained.
In witness whereof, I, the said Moses Poole, have hereunto set
my hand and seal, this Eighth day of May, in the year of our
Lord One thousand eight hundred and fifty-four.
Witness,
B. GOBEY,
12, Cursitor Street,
Chancery Lane.
MOSES POOLE. (L.S.)`