IMPROVEMENTS IN SURFACE CONDENSERS FOR STEAM AND OTHER VAPOURS
Year: 1863

page_text: LETTERS PATENT to William Snell, of No. 16, Clements Inn, in the
County of Middlesex, for the Invention of "IMPROVEMENTS IN SURFACE
CONDENSERS FOR STEAM AND OTHER VAPOURS."-A communication from
abroad by George Wagstaff Yapp, of Paris, in the Empire of France
led the 12th April 1864, and dated the 20th October 1863.
PROVISIONAL SPECIFICATION left by the said William Snell at the
Office of the Commissioners of Patents, with his Petition, on the 20th
October 1863.
I, WILLIAM SNELL, of No 16, Clement's Inn, in the County of Middlesex,
do hereby declare the. uature of the said Invention for "IMPROVEMENTS IN
SURFACE CONDENSERS FOR STEAM AND OTHER VAPOURS," to be as follows:-
The Invention has for its objects first, the arrangement in a small compass
of a much greater extent of cooling or conducting surfaces than can be
obtained by the use of pipes of small bore,and of suchothersimilar appliances
as are at present employed for the surface condensation of steam and other
vapours. Second, the arrangement of such surfaces so that they can be easily
cleaned, repaired, and visited. Third, the obtaining without the aid of any
pump as good, if, indeed, not a better vacuum than is produced at present
either in injection or surface condensers. Fourth, and lastly, the employment
of the current of water used for refrigerating the condenser for measuring
[Price 8d.]
air

page_text: and recording the velocity of the entrance and exit of such water during the
time a steam vessel in which our condensers may be employed is in motion.
The means whereby we realize these objects in the present Invention may
be thus described:-We take trunks, tubes, cases, or other vessels, but by
preference cylindrical tubes made of good conducting substances for heat,and
of such convenient forms & dimensions as the nature of the application may
require, and fill them with an assemblage of divisions of wire gauze, which
may be either in sheets or rolls, so arranged that no vapour or steam entering
the containing vessell or vessels can traverse the same without encountering
many metallic surfaces, or in default of using wire gauze, we obtain an
analogous result; but employing metallic beads or shot, metal filings,
chippings, turnings, nails, bundles of wire or metal rods, which when
assembled in the containing vessels shall afford an infinity of surfaces for the
condensation of vapours, and by keeping up a constant conduction ofthe heat
imparted to them to an outer surface constantly cooled by either radiation,
connection, or conduction, shall render the conducting surfaces always to be
maintained at a temperature that shall effect the condensation of the vapours
brought in contact with them, and at the same time afford a free passage for
the condensed liquids. When wire gauze is employed to obtain the multi-
plication of surfaces, we cause it, by preference, to be cut into a number of
sheets of the required form, choosing such a fineness as shall suit best the
particular description of vapour to be condensed, then assemble such sheets
by means of wire hoops or other means to form a number of diaphragens or
partitions when packed at right angles to the axis of the containing vessel or
tube. For the condensation of steam, we prefer to use gauzes having
60 to 75 parallel wires in a square inch, and which gauzes are designated in
commerce by those numbers respectively. For distillery purposes, where the
vapours of alcohol are to be condensed, we prefer to employ the numbers 40,
35, 30, 25,20,and 15, according as the wine or alcoholic liquor to be distilled
may contain a greater or less proportion of solid matter in suspension. For
the condensation of the essential oils, naptha, volatile products of the
destructive distillation of hydrocarbonaceous bodies, &c., we prefer to use
gauses ranging between the numbers 60 and 35; sometimes we employ an
envelope or cylinder of wire gauze to contain the said diaphragms, and then
insert the whole in the outer vessels or cylinders, taking care in each case that
there is as little solution of continuity as possible between the gauze and the
sides of the containing vessels. We prefer copper as the metal to be used
both for the containing vessels as well as for the assemblage of metallic
surfaces to be placed into them when they are in the form of wire gauze,

page_text: shot, filings, turnings, chippings, nails, bundles of wire or metal rods, but in
default of obtaining gauze made of copper wire, we use as readily that made
of brass wire.
When the condenser is used for marine eugines in steam vessels, we
arrange a number of metallic tubes or cases filled with diaphragms of wire
gauze or other metallic objects, as aforesaid, either in a vertical, horizontal,
or sloping position, connecting both enda of such tubes with separate boxes
or cases, one of which is connected by means of a pipe or pipes with the posts
of the engine cylinder, and the other also by means of a pipe or pipes with a
reservoir, into which the condensed steam may flow as water, & be thence
pumped by means of an ordinary force pump back again into the boiler. The
refrigerating of the said tubes or cases is effected by means of a constant
stream of water brought through pipes having communication with the out-
side of the ship, and flowing through a trunk or receptacle in which the
condensing tubes or cases and their assembling chambers are placed. The
said trunk or receptacle is closed in on all sides except at the openings caused
by the said pipes, which are so arranged thatwhen the ship moves either ahead
or astern a continuous renewal of the refrigerating water will be effected. The
pipes leading to the trunk are to be provided with separate valves or cocks,
which will serve to cut off the supply of water when required, and the trunk
itself is to be provided with a small pump so geared as to be worked by the
engine, and which shall afford the means of clearing the trunk from time to
time of the mud or sediment which the refrigerating water may deposit in it.
The vacuum obtained by the condensing arrangements now described
being far more perfect than that obtained in ordinary surface condensers,
pump is required, and a simple force pump, worked either by the
engine of the ship or by means of a small donkey engine, will be all that
is necessary. If a donkey engine be employed, the steam to worked it may
be produced from a small boiler evaporating sea water, but condensed by
the condenser of the principal engine, and this extra supply of water will
compensate for the difference always found in practice between the quantity
of water vaporized and the quantity of water condensed where surface con-
densers are used, and will thus render it possible to supply the principal
boiler with distilled water alone.
no air
It has been already stated that the water used for refrigerating the con-
denser, when used in connection with marine engines, flows continuously
from the outside of the ship through the refrigerating trunk again to the
outside of the ship, and inasmuch as it is desirable that the engineer should
have at all times certain knowledge that such flow is not in any way

page_text: obstructed, a small wheel turning freely on an axis from which arms diverge
carrying flat vanes, which are inclined at such an angle to the axis as to cause
the latter to turn,when the vanes are arranged to face the current, is placed
within the trunk, the axis passing through the side, and communicating
motion by means of an endless screw to toothed wheels, by whose differential
motion the velocity of the inflowing water will be at all times ascertained.
The present condenser, as herein-before described, is equally applicable for
use in distilleries for replacing the double-bottomed boilers, coils of pipe,and
serpentines used in chemical and pharmaceuitical inanufactures, for the dis-
tillation of sea water for drinking purposes, for warming houses by steam; in
fact for all uses in which it is desired to obtain a result through the con
densation of steam or vapour.
The advantages to be derived from this Invention lie mainly in the fact,
that whereas vapours are bad conductors of heat, their condensation is
restricted to those portions only which are in contact with substances which
are good conductors, and that, therefore, in the pipes of ordinary surface con-
deusers, each atom of vapor has to wait its turn before it can come in con-
tact with the cooling surface. To increase the efficiency of such condensers,
it is necessary therefore to reduce the volume of vapour not in contact with
the pipe surface as much as possible, and which consequently necessitates a
great multiplication of pipes, and the occupying of more space within the
cubic content which may belong to the vessel containing the refrigerating
liquid. Our practice differs in this, that while retaining the same extent of
surface in contact with the cooling fluid, we augment in a very high ratio
the number of conducting surfaces in contact with the vapour, the heat of
any given volume of which is consequently more rapidly robbed, and a
larger precipitation of liquid occurs, amounting in effect to increasing the
efficiency of the refrigerating surface, without enlarging its dimensions.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said William Suell in the Great Seal Patent Office on the 20th
April 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
SNELL, of No. 16, Clement's Inn, in the County of Middlesex, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of October, in the year of our

page_text: Lord One thousand eight hundred and sixty-three, in the twenty-seventh
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said William Snell, Her special licence that I, the
said William Snell, my executors, administrators, and assigns, or such
others as I, the said William Snell, my executors, administrators, and
assigns, should at any time agree with, and no 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 FOR STEAM AND OTHER
VAPOURS," being a communication to me from abroad by George Wagstaff
Yapp, of Paris, in the Empire of France, upon the condition (amongst others)
that I, the said William Snell, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals, 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, thai I, the said William Snell, do hereby declare the
nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement :-
Having described in my Provisional Specification the principles upon
which the Invention is based, as well as set forth in a general manner the
means which is adopted for carrying it into practice, I now proceed to
describe the same in detail.
Sheet 1, Figure 1 of the Drawings is a longitudinal section through a form
of condenser suitable for steam vessels, and in which the tubes are disposed in
a sloping position. R, R., is the refrigerator, and consists of a case made of
boiler plate, the sides and top of which are flat, but having the under side in
part curved, as represented. Four openings a, a, a, a, shown by the
dotted circles, introduce, by means of large pipes or mains communicating with
the outside of the vessel the water into the case, but which can be stopped out
it required by means of suitable valves or sluices in connection with the pipes;
the openings a, a, &c. are placed two on each side of the case, the pipes from
the two lower ones passing out of the vessel at one of its sides, those from the
two upper ones passing out at the other. The condensing arrangement is
composed of a number of tubes made of thin sheet copper, z, zl, 11, 111, two
and a half inches diameter, three and a half feet long, and filled with 580

page_text: ST
diaphragms of wire gauze having 625 meshes to the square inch. Fig. 2
shows a fragment of one of the tubes of the actual size, and explains the
manner of assembling the diaphragms d by means of the brass or copper
rings r. Fig. 3 represents a detached diaphragm, showing the mode by which
the gauze is held in the rings. The rings are made in two parts, and then
fastened together by small copper rivets after the edges of the disc of wire
gauze have been inserted between them, the closeness of the contact being
further increased by pressure brought to bear on the rings during the rivetting.
The rings shewn in the Drawing are inch thick by inch wide, and fit
with some friction into the tubes, in order that there may be as little solution
of continuity as possible between them and the tube, and consequently nothing
to interfere with the free conduction of the heat from the interior to the
exterior surfaces. For the thickness of the tubes themselves of an inch is
preferred, or thereabouts, sufficient strength being obtained by means of the
rings. The tubes are held at one end by a tube plate O, which forms one of
the sides of au enclosed cistern G, and at the other by another tube plate O¹,
forming also one of the sides of a rectangular flat case S, the dimensions of
which are about one-fourth those of the cistern G. The cistern G is
surrounded on three sides by the water in the refrigerator, which also
circulates under its bottom; the end of the refrigerator forms the fourth
side of this cistern, and a cover C closes it above, being bolted down to a
flange f, which passes round the external edges of the cistern. The tube g
leading to the vacnum gauze g¹ passes through the cover. Two pipes A and B
of different diameters communicate with the cistern G; the lower one A
serves to draw off the water, the upper one B to evacuate the vapour formed
by the hot water which runs from the condensing tube. A plate 1, pierced
with holes of a somewhat smaller diameter than the mouths of the tubes, is
bolted to the tube plate O, and serves to retain the diaphragms in their place
in the tubes; a similar plate exists at the other end of the tubes in the case S,
but is not shewn in the Drawing, inasmuch as S is not there represented in
section. A bell-mouthed pipe D passes by means of an elbow-piece through
one of the sides of the refrigerator, and then rises vertically parallel with it;
this pipe forms part of an arrangement represented in Figure 2, Sheet 3, and
will presently be described. The case S which receives the steam coming
from the engine cylinders is detached from the refrigerator on every side,
except the cover, which places it in communication with the man-door of the
refrigerator through the medium of a short wide pipe sand a smaller pipe a;
the case S is supported below on small rollers placed in the refrigerator,
which permit it to move freely in the direction of the axis of the tubes. The

page_text: man-door N which closes the upper end of the refrigerator is bolted to an
internal flange fl. On this door are cast two tubulures M and m. Within M
a gun metal flanged collar Q passes down to encircle the pipe S, which also
passes through the lower end of the tubulure M, on which a collar is cast,
and which forins the bottom of a stuffing box e, e, when the gun metal ring is
passed over the top of S. The steam pipe P is bolted by means of its flange
to the flange of the tubulure on M, and also serves to hold down the gun
metal collar Q, the flange of which comes between. The result of this
arrangement is that the condensing tubes are free to expand and contract
in the direction of their length without hindrance, and at the same time to
carry with them the case S, thus all chances of rupture and twisting of the '
tubes are avoided, as well as fatigue of the end joints in the tube plates. The
arrangement m is of a similar character to that of M, and is furnished to allow
the pipe a to pass steam-tight through the cover N, and at the same time to
admit of its sliding in one direction or the other when any movement takes
place in S. A pipe u placed in the highest part of the refrigerator allows of
the escape of the air when the refrigerator is first filled with water.
The action of the apparatus hardly requires description:-The steam
arrives in the steam chest S, penetrates the tubes, and then finding itself in
the presence of a multitude of conducting surfaces ready to carry off its
sensible as well as its latent heat, immediately condenses into water, which
then runs through the gauzes and empties itself at the opposite end of the
tubes into the cistern G. The diaphragms of gauze form in fact a vast
assemblage of small tubes of short lengths separated from one another at their
ends, but in the closest contact possible at their sides, through which the heat
of the steam passes rapidly away to the rings, and thence by the walls of the
containing tube to the water in the refrigerating cistern, which is moreover
constantly being changed by the motion of the vessel aided by an alteration of
its density due to a rise of temperature. It follows from these conditions that
my condenser differs from othersurface condensers where tubes are employed,
as indeed I have already explained in my Provisional Specification, in this,
that the interior of the tubes in ordinary cases present only an empty and
non-conducting space, whereas in my system the steam is robbed of its heat
equally in the centre of its volume in the tube as at the sides, finding, in fact,
conducting surfaces at all parts of its section; or to state the difference even
more simply, the tubes in my condenser act by virtue of their cubic contents
as well as their surfaces, and not by the area of the latter only, as is the case
in the ordinary arrangements,

page_text: Such being a general description of the condenser, it remains now to
describe the other apparatus used in connection with it.
Sheet 1, Fig. 4, represents an arrangement for freeing the condenser from
air previous to bringing it into action, it being well known that the air notably
interferes with the instantaniety of action of the condenser when the engine is
first started. C is a cone made of thin sheet copper closed at the base, but
open at the top; a is a pipe communicating with the steam box S of the con-
denser, as already described, and is provided with a stop-cock a¹; b is a pipe
in connexion with the steam chest of the boiler, and which after entering the
cone is bent upwards to occupy the axis of the latter; this pipe terminates
near the mouth of the cone in a small nozzle causing the steam to escape
from it in a jet, a stop-cock is also furnished to this pipe. Before starting the
engine the stop-cocks on a and b are opened; an escape of steam then takes
place through the mouth of the copper cone, the orifice of which is regulated
so that the inverted cone of steam formed by the issuing jet shall exactly fill
the opening, and draws out with it through the pipe a the air contained in the
condensing tubes, &c. After the engine has started, and the first discharge of
steam from the cylinders been voided through the pipe a and the cone, the
stop-cocks on a and b are closed, and the condenser brought into action.
Sheet 3, Fig. 2, displays the means adopted for emptying the refrigerator of
the mud and sediment which may collect in it, and so encrusts the tubes during
river navigation, etc. It consists of a standard pipe D, D, shown in the
Figure, to be composed of a standard and elbow piece flanged and bolted, in
order to pass beneath the tubes and out by the side of the refrigerator, see
Fig. 1, Sheet 1) bell-mouthed at bottom, and terminating above in a valve
chamber A. Branching laterally from the valve chamber is another standard
pipe B, which after rising some short distance bends over to form a spout. C
is a conical plug worked by a screw c, which is turned by the handle d.
Between the bottom of the refrigerator (Fig. 1, Sheet 1), which forms a kind
of basin to collect the mud and the bell mouth of the pipe D, an interval is
left of about a couple of inches. The spout of the pipe B is always kept at
its highest part considerably below the level of the line of flotation of the
ship. The action of the apparatus is exceedingly simple When it is required
to purge the condenser the plug is raised by the screw, thus giving free
passage from the pipe D to the pipe P, the difference of level of the water
outside the vessel and that which is contained within the refrigerator then
causes the sludge which may have collected at the bottom of the latter to
rush up the pipe D, and to be discharged by the spout of B into any vessel

page_text: "
placed to receive it. The clearing of the refrigerator of mud may thus be
often practised without interruption to the condenser whilst in action,and the
slime which forms a constant source of injury to the surfaces of the tubes in
ordinary surface condensers may by this easy method for preventing its accu-
mulation be rendered innocuous in its effects. For feeding the boiler with
the water proceeding from the condensed steam, a description of pump is
employed which entirely does away with the requirement of an "air pump
to first pump out the condenser before bringing into use the feed pump. The
condensation being complete in the tubes of my condenser,no steam has to be
removed with the water,although it must not at the same time be understood
that by my claim of the suppression of the "air pump," I deny myself the
means of removing the va; our which rises in the cistern (G. Fig. 1 Sheet 1),
and which if there suffered to remain would injure the vacuum. This vapour
is removed, as shall now be shown. Fig. 1, Sheet 3, represents a vertical
section through the pump employed, and which is composed of two chambers
A and B, the latter much smaller than the former and placed above. A piston
rod E is common to both pistons P and p, the action of which, as regards the
valves of the separate barrels, is, however, different in each case: thus V, Y,
X, Z, being the valves, and supposing the upstroke of the piston about to
commence, the valve X (giving exit to the partly or wholly condensed vapour
in B), and the valve V (making communication with the cistern G) will open
the valves y (communicating with the feed pipe to the boiler) and Z (opening
an exit for the vapour in the cistern G), at the same time closing; the down
stroke will of course reverse this action. As it happens that the vapour is
disengaged most freely from the water at the time when the valve V is closed
the pump B is brought into action at the right moment. The valve box X
communicates with a pipe leading separately to the boiler, and serving to
carry off the partly or wholly condensed vapour which may exist in B. The
form and arrangement of the valves, pistons, cone, etc., being quite of an
ordinary character further description is unnecessary.
Although a form of condenser is described in which the tubes are disposed
in a sloping position in the refrigerator I by no means confine myself to this
arrangement, neither to the length of the tubes nor to their diameter and
thickness; the number of diaphragms which they shall contain, and the mode
of assemblage of the latter, must likewise be governed by circumstances; I
also claim the right of substituting for the wire gauze any one of the materials
mentioned in the Provisional Specification as capable of replacing the gauze
for filling the tubes.

page_text: be
m is the
Sheet 2, Fig. 1, represents a form of condenser in which the tubes are
arranged vertically. R is a large rectangular case made of boiler plate,
having four horizontal pipes a, a, all, all, leading into it, and making com-
munication with it and the outside of the ship in which the condenser may
placed; these tubes are closed by sluices or other suitable valves, when it is
desired to prevent the entrance of the water. This case, which forms the
refrigerator, is closed with a circular cover c at top, and rests below upon a
cistern N, of which its bottom forms the upper side, and which is intended
to receive the water coming from the condensation. The cover carries a
tubulure and stuffing box, the details of which have already been described for
Fig. 1, Sheet 1. The condensing tubes t, t1, 111, 111, open at one end into a
rectangular flat case S, which receives the steam, and at the other into the
cistern N. From the upper side of S proceeds a wide tube sliding within the
tubulure on the cover O, and differing nothing in its arrangement from that
already described for Fig. 1, Sheet 1. The cistern N is provided with a pipe
for drawing off the water W, and another smaller tube V serving for the
evacuation of the vapour rising into the cistern from the water.
tube leading to the vacuum gauze. This form of condenser is also provided
with the sludge pip: D and air purge a, which are shown on Sheets 3 and 1,
Figs. 2 and 4; also a tube u for allowing the air to escape from the refri-
gerator on first admitting the water into it. As at present constructed it may
be fairly asserted that surface condensers are their limited employment almost
enterely to the immense difficulty of preserving their cooling surfaces effective
by removing the soiling matters which attach themselves to them. It is
indeed easy to understand how great must be the labour, and how imperfect
the success attending any attempt to clean even the outside, much less the
inside, of several thousand small tubes, of which the bore does not exceed half
an inch, often less, and which are often so closely assembled, in order to save
space, that access to them is almost impossible without taking the condenser
to pieces. In this system this great difficulty of cleaning no longer exists.
The tubes, in the first place, are much fewer in number than in ordinary
surface condensers; and, in the second, their diameter, together with the mode
of arrangement of their diaphragms, enables their interior, as well as their
exterior, at all times to be visited and got at. The diaphragms are retained
in their places by false tube plates placed at each extremity of the tubes (0,01,
Fig. 1, Sheet 1), as already described, and on remaining these it is easy to
drive out the diaphragms by means of a wooden cylinder inserted against the
rings. As regards the exterior surfaces, the greater space between the tubes,

page_text: which can be obtained in consequence of their not being numer..us, admits of
its being easily manipulated, whilst the sludge pipe (Fig. 2, Sheet 3) defends
it from ever becoming seriously incrusted.
When the condenser is applied to stationary engines it is obvious that other
means must. be resorted to in order to renew the water in the refrigerator, but
the choice of such inust necessarily be left to the position and circumstances
under which the engine is already erected, and cannot therefore be described
in this place. When the condenser is for use on board ship it is desirable
that the engineer should at all times have certain knowledge that the flow of
water in and out of the refrigerator is not in any way obstructed. I provide
for this by means of a very simply constructed indicator:-A small wheel
turning freely upon an axis is arranged horizontally within the refrigerator in
a line with the direction of the inflowing current of water, and carries several
flat vanes inclined at such an angle to the axis as to cause them and conse-
quently the wheel to turn when the moving particles of water communicate
their impulse to them. This movement of rotation is accordingly fast or slow
in proportion as the current, which flows through the refrigerator, becomes
more or less rapid owing to the increased or relaxed velocity of the vessel. To
render it therefore appreciable, the axis carrying the vanes is provided with an
endless screw cut on it, and working into a toothed wheel placed below it on
an axle carried by a forked lever, and by means of which the wheel may be
raised into contact with the screw, or separated from it at option; this same
axle carries a pinion working into another wheel also carried by the lever, but
which turns much more slowly than the first wheel. The second wheel is
provided with a bevelled pinion working into a bevelled wheel threaded on a
vertical shaft, which is collared into the cover of the refrigerator, which also
gives passage to the rod for raising the lever. The upper end of the vertical
shaft carries a bevelled pinion gearing with a vertical bevel wheel, which
carries on its axle a cardboard disc, on the edges of which a mark is placed,
this, when seen through a slit made in a screen placed in front of the
revolving disc, serves, by the number of its recurrences during a selected unit
of time, to indicate the speed of the current passing through the refrigerator.
My condensing tubes are applicable to the condensation of other vapours
equally with that of water. In distilleries they will advantageously replace
the worms at present used in the refrigerators. The description of wire gauze
I prefer for such applications have already been signalized in the Provisional
Specification; they may also be advantageously substituted for the coils
grilles,and false bottoms used for heating liquids,drying, baking, &c., they wil.
economically replace the arrangements of steam pipes used in warming houses

page_text: factories, &c., in fact they may be generally used for all processes and applica-
tions where heating by steam or the obtaining of liquids by condensation of
vapours is intended. As compared with other surface condensers, this Invention
hasafforded thefollowing results :-Thehighestpowerof condensation obtained
in the condensers of this description placed in steam vessels has never, to my
knowledge, exceeded 12 lbs. per hour per square foot of refrigerated surface,
while in ordinary cases a greater amount of condensation is not expected than
3 lbs. per square foot per hour. My experience shows that a tube 1 yard long,
2 inches diameter, and containing 500 diaphragms of wire gauze having 625
meshes to the square inch, will condense per square foot of refrigerated surface
48 lbs. of steam of the pressure of 30 lbs. on the square inch, the mean tem-
perature of the refrigerating water being being 136° F. This is equivalent to a
gain in condensing power of over 700 per cent. as compared with the highest
results I have quoted for the condensers at present in use, and of 2500 per
cent. as compared with ordinary instances.
Having now described the best methods with which I am at present
acquainted for carrying this Invention into practice, as well as pointed out
those applicatious for which I believe it to be most useful, I will now shortly
set forth the claims in connection with the same.
CLAIMS.
I claim, First, the use of tubes, trunks, cases, or other vessels to be used as
condensers when filled with an assemblage of conducting surfaces, such as
wire gauze, perforated metal plates, bundles of wire or rods, nails, metallic
shot, metal borings or turnings, &c., and which shall be so arranged in the
tubes as to afford sufficient interstitial space for the passage of the vapours
and the escape of the condensed liquids which shall result.
Second, the application of the steam jet for purging the condenser of air in
the manner described.
Third, the arrangement for clearing the refrigerator of the mud and sludge
deposited by the water.
Fourth, the double-chambered pump to be worked by an arrangement of
valves in the manner described, but not the form or description of valve which
we have indicated.
Fifth, the use of the apparatus described for indicating the flow of water
through the refrigerator by the methods herein-before described or by any
analogous means.
Such being the nature of this Invention and the claims in respect of the
same,
in conclusion I insist upon the following advantages:-

page_text: 1. An increased condensing power in an apparatus of very many times
smaller dimensions than those at present in use. This advantage alone wil
render, it is expected, these surface condensers applicable to vessels with very
high power, and in which the present surface condensers are only capable of
being introduced as accessories to the injection condensers on account of their
cumbersomeness.
2. A diminished expense in erecting and maintaining, principally due to
the reduced dimensions of the condenser.
3. Great facilities for claiming and the avoidance of any failure in the
condensation arising from incrustations on the exterior surfaces, or from
failing of the interior surfaces of the tubes.
4. Suppression of the air pump, inasmuch as the condensation being per-
fectly accomplished in the condenser itself only a feed pump is required, a
small extra barrel being employed solely for taking away the vapour formed
from the hot water in the condenser cistern.
In witness whereof, I, the said William Snell, have hereunto set my
hand and seal, this Nineteenth day of April, in the year of our, Lord
One thousand eight hundred and sixty-four.
W. SNELL. (L.S.)