IMPROVEMENTS IN BOILERS, AIR HEATERS, L STEAM CONDENSERS, AND ANALOGOUS CONSTRUCTIONS FOR TRANSFERRING HEAT FROM ONE FLUID TO ANOTHER.
Year: 1870

page_text: LETTERS PATENT to Samuel Dyer Tillman, of Jersey City, in the
County of Hudson, State of New Jersey, in the United States of
America, for the Invention of "IMPROVEMENTS IN BOILERS, AIR HEATERS,
L
STEAM CONDENSERS, AND ANALOGOUS CONSTRUCTIONS FOR TRANSFERRING HEAT
FROM ONE FLUID TO ANOTHER.'
"
Sealed the 10th June 1870, and dated the 25th April 1870.
COMPLETE SPECIFICATION filed by the said Samuel Dyer Tillman at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 25th April 1870, pursuant to the 9th Section
of the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, SAMUEL
DYER TILLMAN, of Jersey City, in the County of Hudson, State of
New Jersey, in the United States of America, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
BOILERS, AIR HEATERS, STEAM CONDENSERS, AND ANALOGOUS CONSTRUCTIONS FOR
TRANSFERRING HEAT FROM ONE FLUID TO ANOTHER, and have petitioned Her,
"

page_text: Majesty to grant unto me, my executors, administrators, and assigns,
Her Royal Letters Patent for the same, and have made solemn Declaration
that I am the true and first Inventor thereof.
NOW KNOW YE, that I, the said Samuel Dyer Tillman, do hereby
declare that the following Complete Specification, under my hand and
seal, fully describes and ascertains the nature of the said Invention, and
in what manner the same is to be performed, in and by the following
statement:-
I will first describe what I consider the best means of carrying out my
Invention, and will afterwards designate the points which I believe to
be new therein.
The first part of my Invention relates to heaters for heating gaseous
fluids, ordinarily atmospheric air, by the aid of steam or hot products of
combustion flowing through tubes. I provide in such structures means
for increasing the heating surface, and for directing the flow of the
fluids so that the fluid to which the heat is communicated will be
removed entirely, and its place supplied by other fluid at the original
low temperature instead of remaining and flowing along the heating
surfaces in contact therewith.
I shall describe this part of my Invention as applied to heaters having
pipes in the ordinary cylindrical form, but it will be understood that the
pipes or equivalent parts may be of oval section, or of rectangular,
triangular, or any other form of section if preferred.
The accompanying Drawings form a part of this Specification and
illustrate this portion of my Invention.
Figure 1 is a side elevation, Figure 2 is a plan view, Figure 3´is
a vertical section, Figure 4 is a horizontal section of my heater
complete.
Figures 5, 6, and 7 show parts of constructions which involve some
of the novel features of my Invention, but not in what I consider the a
best form.
Figure 8 is a cross section of a single pipe with its oblique transverse
plates cast in one piece therewith or made by uniting a series of trans-
verse plates to a plain pipe.
Figures 9 and 10 are cross sections of such pipe or a corresponding a
pipe showing different forms of the cross section of the pipes and different
outlines for the plates.

page_text: Figure 11 shows a.modification which I propose to adopt when my
device is used as a surface condenser. In this case the heated fluid inside
the pipes is the exhaust steam from a steam engine.
Figure 12 shows the application of my improved pipes to an ordinary
stove. In this case the heated fluid inside the pipes is simply the hot
products of combustion.
Similar letters of reference indicate corresponding parts in all these
Figures. The Drawings represent the novel parts with so much of the
ordinary parts as scem necessary to indicate their relation thereto.
Referring to the Figures 1, 2, 3, and 4, A is a hollow ring forming
the base of my apparatus; A is a corresponding ring forming the upper
portion of my apparatus; B, B, are tubes extending from the lower
ring A¹ to the upper ring A'; a pipe a³ conducts steam, highly heated
air, or the like into the upper ring A³, and a pipe a¹ allows the same
to flow out in a partially cooled condition from the lower ring A². The
direction of the current may be reversed, or, in the case of a steam
heating apparatus, it will be readily understood that a large proportion
of the escaping matter will ordinarily be in the condensed form as
water; C, C, are legs or supporting arms which hold the whole a little
up from the floor or other support. So far as has been yet described
the apparatus is believed to involve nothing new. The several rings as
also the tubes may be of cast iron cast together by skilful coring, or the
parts may be made separately and joined by screwing or other suitable
means. D, D, are plates or discs of thin metal cast, welded, or
otherwise formed on the tubes B, and stand nearly or quite at right
angles thereto; they perform the double function of conducting the heat
from the pipes B outward and present a great extent of heating surface
to warm the air on the exterior and to deflect the current of air and
compel it to flow crosswise of the tubes. The arrangement here
represented provides for a current of air to flow inward in all directions
and to rise in the central space within the rings A', A³. Some of the
air will rise directly upward through the clear and unobstructed space
in the centre. This quantity may be limited by reducing the hight or
increasing the width of the legs C, or there may be a special valve
or regulating device, not represented, by which such passage may be
adjusted at will. In any event a large quantity of air will flow in
radially between the pipes B, and will become heated by the contact, not
only with the pipes themselves, but also with the plates D.

page_text: As ordinarily arranged the particles of air heated by contact with the
lower part of each pipe B rises and envelops the upper part of the said
pipe in a stream of warm air, so that the upper part of each pipe is only
slightly efficient as a heating surface. It is not exposed to a direct
current of cool air; but my plates D completely guard against such an
upward flow along the pipes, and they compel the air warmed at any
given point on the exterior of a pipe to move inward out of the way,
and to leave the spaces above entirely unaffected thereby. In other
words, the space below each plate D is isolated by the plate from the
space above it and each performs its heating function independently.
I can provide any height of chimney above the top of my apparatus
to enclose the currents of air heated thereby, and to thus create a strong
upward draft, and a powerful suction inward through the space between
the plates D. This action resulting from well known laws may be
modified at will by removing such chimney, raising it above the
top of my apparatus, perforating it, or providing it with a damper, or
otherwise.
When my apparatus is used as a condenser it will be understood
that the steam is thrown into the pipes B from the engine, and the
current of cold air conducts away the heat in the same manner, 'as has
been before described, and this heated air may be utilized for warming
rooms.
In some cases, where no such use can be made of the heated air, it
may be of particular service to place the apparatus at the bottom of a
tall chimney so as to thereby increase the vigour of the circulation of
cold air. The effect may be still further increased in some instances
by heating such chimney with the products of combustion from the
furnace, or increasing the draft by a blower, a steam jet, or other approved
means.
I can also increase the draft or the circulation of the air by artificial
means in using the apparatus as a steam heater or stove. In this case
the condenser will be most effective if both the tubes B and the plates D
are made of thin copper, and it is evident that the strength of the
plates D will allow the use of extremely thin copper tubes B, and in
like manner much thinner tubes than usual of any other metal may be i
used when thus strengthened by the surrounding series of plates. In
order to communicate the heat from the pipe to the plate with the
greatest rapidity the contact surface between the two is increased by

page_text: making a hole in the disk smaller than the diameter of the pipe, and
then making radial cuts in the plate around this hole, extending so far
that when these segments are bent at right angles the plate will just
fit on the pipe, and when iron is used these segments are welded to the
pipe so that the heat will be communicated through them rapidly into
the plate.
When used as a condenser the system of pipes, as shown in Figure 11,
may be set in a cylindrical vessel open at the top and closed at the bottom
so as to form a receptacle for cold water, which is let in at the bottom
at W, and allowed to flow out at W. By thus applying cold water to
complete the condensation I provide for cases when the air. is not cold
enough to effect perfect condensation, as might be the case during the
warmer months. The pipe conducting the water from the condenser
is passed through a vessel containing cold water at its bottom and con-
nected with a warm receptacle, not shown in the Drawings, from which
it is pumped directly into the boiler to be again converted into steam.
I do not confine myself to the precise degree of curvature or the
precise distance apart of the plates D, D. I have represented them
as being matched together edge to edge, so that the plates D on one
tube coincide with the corresponding plates on the adjacent tube on each
side. I prefer this arrangement, but a part of the advantages of my
Invention may be secured by allowing the plates to interlock or lap
on each other, or again, if of insufficient size to meet in case the plates
are plane, I esteem it important to mount them at a considerable
inclination so as to favor the motion of the air in the desired direction
by the tendency of the warmed air to rise. But a portion of the
advantages may be secured by mounting such plates in planes at right
angles to the axes of the tubes.
The plates may be made of wrought iron, struck out by dies or the
like, and secured. by welding, brazing, soft soldering, or other suitable
means. In order to allow for the inclination the hole which receives the
tube should be made correspondingly elliptical. I can modify the effect
by varying the thickness and substituting other material, as brass, for
iron. I propose for cheap work casting the tubes B with the plates D
thereon in a single piece.
The effect may in some cases be modified with advantage by inclining
the plates D in the opposite direction, and blowing the cold air into
the centre of a series of pipes arranged as represented. In such case

page_text: the interior of the upper ring A² may be wholly or partially closed with
advantage.
Any tasteful scrollwork or other openwork protection may be mounted
on the exterior of my heater when it is used for warming apartments.
When my improved pipes are employed for heating air by means of
the gaseous products of combustion I can attach them to the upper
part of a heat generator or stove of cylindrical form, as shown in
Figure 12. In this case the lower end of the pipes open directly into
the heat generating chamber, so that the pipes may be easily cleaned
without taking the apparatus apart, it being only necessary to open the
door of the stove when cold, and holding in one hand a short rod having
a scraper at its upper end, to rapidly remove the soot from each pipe.
In the hollow circular ring to which the upper ends of the tubes are
attached is an opening to which is fitted the pipe for the exit of the
smoke and gases. In this case the plates on the pipes are inclined so
as to be lowest on the outside, thus the air is drawn in from the outside
and discharged from within the hollow ring at the top. It is obvious
that fresh air may be brought from without and after being heated in this
apparatus be carried to all parts of a building for the purpose of warming
it. I have only described the simplest form in which my improved.
pipes may be applied to the ordinary cylinder stoves.
The second part of my Invention relates to boilers.
The accompanying Drawings forming a part of this Specification
illustrate this portion of my Invention.
Figure 13 is a central vertical section, and Figure 14 is a horizontal
section. The additional Figures are only of importance in illustrating
modifications of portions of my boiler, and will be explained below.
Similar letters of reference refer to like parts. G is a stout plate of iron
forming the bottom of my boiler, and H is a corresponding plate forming
the top thereof; M is a cylindrical shell, which joins the bottom G with
the top H, and forms with the said top and bottom an upright cylin-
drical boiler shell, having the strength and other qualities necessary
to resist the pressure of the steam; B, B, are tubes extending longi-
tudinally through the boiler, and set in the upper and lower ends in
the ordinary or any suitable manner, to allow a portion of the products
of combustion to pass through these tubes and impart their heat to the
water. The tubes B are arranged in a circle or series. I have represented
six, but the number may be increased or diminished without sacrificing

page_text: all the advantages of my Invention. It is important that they be
arranged in a circular series, each at a proper distance both from the
centre and circumference of the cylinder, as will presently appear.
D, D, are plates of wrought iron or other suitable material mounted
on the tubes B, and standing obliquely across, as represented. They
may be secured in any ordinary or approved manner, as, for example, by
welding, brazing, or soldering, and they may be formed of such size and
so arranged as to match each other edge to edge, that is to say, the edges
of the plates D on one pipe B may coincide with the edges of the
plates D on the adjacent tubes B, but this condition is not absolutely
essential to the success of my Invention. The degree of the inclination
of my plates D may be varied. Instead of making them absolutely plane
they may be curved, as indicated in Figure 17, or they may be curved in
the other direction, so that a series of plates extending horizontally
around in the interior of the boiler coinciding at their edges, as
represented, may present the contour of a segment of a cone instead
of the segment of a pyramid, which latter form will result from the use
of plane plates. Various other variations may be made by any good
mechanic without departing from the principle or destroying the
beneficial effect of my Invention. When my boiler is set in brickwork
I leave a little space, say, one inch more or less, between the exterior of
the cylindrical surface M and the interior of the brickwork. The boiler
having been filled with water to a proper extent, and provided with
suitable connections for the discharge of the steam, and for supplying
feed water, as will be obvious, a fire is maintained below on any ordinary
or suitable grate, and a portion of the draft is allowed to flow upward
through the pipes B, while another portion is allowed to rise in the
narrow annular space around the exterior, but I prefer that the hot gases
shall in all cases be finally discharged only through the said pipes.
Under these or any analogous conditions my plates D perform important
functions, both by increasing the heating surface and deflecting the
currents of water and steam. As tubes in upright boilers have been
heretofore generally arranged the steam produced on the lower portion
of any tube rises in contact with the tube, and partially or entirely
prevents the access of the dense water to the upper portion of the tube.
In my improved boiler the particles of steam generated below any given
plate D rise directly, dragging the surrounding water with them until
they strike the said plate, and are thereby deflected outward, while dense

page_text: water from near the axial line of the boiler flows onward to take the
place of the water so removed, to become in its turn partially changed
into steam and rise and move outward. When, as above provided, the
cylindrical shell M is also a heating surface the steam generated on its
inner surface also rising generates an active upward current around the
entire circumference of the boiler. On reaching the water surface the
particles of steam are liberated, a current of water flows inward from all
sides and descends in the centre of the boiler. In its descent it supplies
the several spaces between the plates D with an outgoing current of
water, and thus an active round or circulation obtains. Que result
attained by my tubes covered with a series of projections or plates D is
that steam will be generated faster than by plain tubes, through which
the hot products of combustion are passing. The temperature of my
tubes cannot be raised to such a point that steam will not be generated
freely, since the outside transverse plates or projections. are rapidly
conducting the heat from the tube itself and preventing its being
overheated. It seems now to be well settled that steam is generated
most rapidly at a degree of temperature far below that at which water
assumes the spheroidal condition. The best temperature for generating
steam under pressure of one atmosphere is probably not far from 400
to 500 degrees Fahrenheit, and as the pressure is increased it will be
necessary to increase the temperature of the tubes. To prevent the
bottom G from overheating it may be covered with radial projections,
which would not seriously retard the circulation of the descending water,
but it is most feasible and economical to place a non-conducting
substance like soapstone under the bottom, having in it holes corre-
sponding with the lower ends of the tubes so as to allow the heat to
pass into the tubes. I propose in some cases to use one of these tubes B
with its plates D mounted centrally in a larger tube, a series of which
larger tubes properly constructed and connected at the top and bottom,
as in many well-known forms of sectional boilers, shall form a boiler.
And in some cases the attached plates or projections on the tubes may
form a crescent-shaped opening above and below, and the whole may be
cast together. This will increase its strength. Figure 15 represents such
a cast-iron section having an inclined position, and Figure 16 a cross
section on line a, x, in Figure 15, showing how the water may pass freely
under the central tube and the steam above it. The plates D, D, may
also be used on horizontal tubes in a horizontal boiler for the purpose of

page_text: increasing the heating surface, in which case the plates are perpendicular
to the tube, and the tubes are so arranged as not to be in the same
vertical line.
I propose under some circumstances to modify the provision for
presenting the products of combustion in my boiler by leading the whole
up through the tubes B, and then leading down the partially cooled
gases, either spirally or in any other suitable manner around the exterior
of the shell M.
With any arrangement for presenting the hot gases to the exterior of
the shell the advantage of the circular arrangement of the pipes B and
of the inclination of the several plates D rising from the centre outward
in all directions is obvious, because the current of rising steam and
water induced by the heating effect of the several pipes B is by such
arrangement combined with the heating effect of the shell. In case no
heat is applied to the exterior M the plates D may be inclined in the
opposite direction, and the current of mingled steam and water may then
rise through the central space, assisted or not by the heat of a tube or
flue in the centre, which should have none of my cross plates D. With
that arrangement the dense water will flow down between the exteriors
of the plates D and the interior of the shell M. For stationary boilers
I much prefer the arrangement represented.
I am aware that many devices have been before proposed for variously
promoting the circulation of water in boilers and for increasing the
conducting or convecting surface. But I am not aware of any previous
construction or arrangement similar or in its effects equal to mine. I
can make my pipes very effectively of cast iron by properly coring, and
in such case propose to make the plates D in one piece with the tubes B to
which they belong. I can provide two or more series of tubes B with
their plates D when the boiler is of sufficient size to require them, in
which case the plates D will be inclined in opposite directions on the
two sets of tubes. I esteem it an important advantage of my Invention
that it abstracts heat from the gaseous contents of the tubes with more
than usual effect. This is due both to the presentation of the water in
a dense state and in very active currents, and also to the conducting
effect of the plates D, and I believe it preferable to make the tubes B
in a single series, and of such size as may be required to carry a large
proportion of the draft of the furnace. Morcover, I propose to use my

page_text: improved method of generating steam by making attachments to boilers
of other constructions which may be already in use.
I have referred to the interposition of soapstone to defend the lower
plate G, and have represented the tubes as double, or as enveloped each
with a broad inclined thimble between each plate D and the next above
or below. Such would form a convenient mode of holding the plates D,
if not joined by solder or the like to the inner and main tubes B with
sufficient force. But these provisions for reducing the transmission of
heat may be objectionable where much steam is made in a small boiler,
and can be entirely dispensed with without affecting the objects of my
Invention in any weakening or damaging degree.
1st. I claim the pipes B with the series of plates D thereon as
specified, for the purposes herein set forth.
2nd. I claim the pipes B and transverse plates D or their equivalents
in combination with means for supplying steam or heated fluid to the
interior of the said pipes and for causing a current of air or analogous
fluid to flow through the spaces between, substantially in the manner
and for the purposes herein set forth.
3rd. I claim the combination of a series of such tubes and plates to
form a hollow cylindrical structure having the hollow rings A', A², or
their equivalents connected as specified, with or without the supporting
legs C, and constituting a portable heater or cooler and condenser,
substantially as and for the purposes herein set forth.
4th. I claim the within described steam boiler composed of the
pipes B, cross plates D, and boiler shell G, H, M, combined and arranged
to serve relatively to each other and to the fluids circulating therein,
substantially as herein set forth.
In witness whereof, I, the said Samuel Dyer Tillman, have here-
unto set my hand and seal, this Twenty-ninth day of March,
1070
SAMUEL DYER TILLMAN. (L.S.)
Witness,
THOMAS DREW STETSON,
Patent Agent, New York.