IMPROVEMENTS IN WATER TUBE STEAM GENERATORS
Year: 1879

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS IN
WATER TUBE STEAM GENERATORS." A communication from abroad by Charles
Ward, of Charleston, Kanawha County, State of West Virginia, United States
of America
Sealed the 23rd March 1880, and dated the 8th October 1879.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark at
the Office of the Commissioners of Patents on the 8th October 1879.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVEMENTS IN WATER TUBE STEAM GENERATORS." [A
communication from abroad by Charles Ward, of Charleston, Kanawha County,
State of West Virginia, United States of America.]
This Invention is an improvement in the class of boilers or steam generators
formed of concentric or other coils of tubes through which the water circulates in a
continuous round, and the Invention consists in the construction and arrangement
of parts as hereinafter described.
The main parts of the generator proper are an outer coil or connected series of
pipes, a corresponding or similar inner coil or series, vertical tubular connections or
stand pipes connecting the tubes of each series, and a vertical separating drum or
cylinder. The two coils or series of pipes are concentrically arranged and enclosed
by a concentric iron casing having a fire-brick lining, the separating drum or cylinder
being outside the casing. The inner series also surround a vertical cylinder having
a facing of fire-brick. Each coil consists of two series of parallel inclined tubes (of
which there may be any number or series) which are joined to the two vertical
tubular connections or stand pipes. The latter are placed on opposite sides of the
complete coil, and the tubes, which are of semi-circular or other form, extend from
one to the other, to both of which they are connected by suitable joints. The stand
pipes are set on the division wall of the fire box, and thus serve to support the
whole system of pipes or coils. The flame and gaseous products of combustion pass
up from each portion of the fire box in the several annular spaces between the fire
brick casing and outer coil, between the two coils, and between the inner coil and

page_text: the central fire-brick post or cylinder. Thus the fire-brick surfaces of the casing
and the central post or cylinder radiate heat on the outer and inner coils respectively,
and the flame and heat act on them from the space within, so that fuel is economised
and steam generated rapidly.
The manner of connecting the coils or systems of pipes with the separating drum
or cylinder is as follows:-The drum or cylinder is provided with two pairs of
horizontal tubular arms, the two of each pair projecting on opposite sides near the
top and bottom of the drum or cylinder. The two stand pipes which are nearest
the drum or cylinder are connected at the bottom with the lower arms of the drum
by curved tubes, while the stand pipes which are farthest from the drum are
similarly connected with the upper arms by other tubes. Thus the lower portion
of the separating cylinder is in communication with the lower ends of one pair of
stand pipes, and the upper end in communication with the upper ends of the other
stand pipes. From this arrangement it results that when the proper degree of heat
has been attained the water in the inclined tubes forming the coils becomes expanded,
and in part converted into steam, so that a circulation sets upward in all the tubes
of both systems or coils from the stand pipes to which the lower ends of the inclined
tubes are connected toward the other stand pipes, to which their higher ends are
connected, where the slow moving currents mingle into one which flows upward to
the top of the latter, and there divides into currents that pass through the connecting
tubes to the upper arms of the separating cylinder or drum, and thus enter the
upper portion of the separating cylinder. The water is separated from the steam
immediately upon entering this cylinder, since the water falls by its own gravity
into the main body of cooler water in the lower part of the cylinder. The steam
is taken from the upper portion of the cylinder by a pipe, but to prevent the water
which discharges through the said connecting pipes from following the course of
the steam I interpose a perforated or wire gauze screen between such pipe and tho
tubular arms to which the connecting pipes are attached. Said screen is arranged
horizontally, and attached to the sides of the cylinder. As the heated water rises
in the machine tubes forming the coils, its place is supplied by the cooler and
heavier water flowing from the lower part of the separating cylinder through the
lower pair of connecting pipes, which becoming heated in turn ascends through the
stand pipes, and is finally delivered into the separating cylinder, as before described,
and thus the circulation goes on in a continuous round, the action depending on the
difference in gravity between the hot water in the systems of pipes and the cooler
body of water in the separating cylinder.
When the hot water discharges from the tubular arms into the separating cylinder
and mingles with the colder water therein the slower motion of the current through
the latter (owing to its increased diameter) favors the deposition of mud or sediment,
which is collected in the bottom of said cylinder, and may be removed therefrom by
discharge cocks.
Feed water may be supplied to the separating cylinder at any convenient point;
the joints of the connecting pipes with the separating cylinder are such that they
may be readily detached. Thus each system or coil of pipes may be removed when
necessary for the purpose of repair or other reason, and the use of the other continued
the same as before.
There may be any desired number of coils or concentric series of tubes.
The inclined tubes of such coils may be round, square, oval, or of any other form in
cross section.
They may also have various curves or angles instead of being semi-circular or
concentric, so that the coils instead of being circular in plan may be oval, square,
oblong, or of other suitable shape. The coils or systems of pipes may be set at various
angles or in various positions, as circumstances or judginent may dictate. For
example, they may be inclined at an angle of 40°, or even placed horizontal, but I
propose to preserve in all cases the inclination of the tubes and their connection
with the stand pipes.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Melville Clark in the Great Seal Patent Office on the
8th April 1880.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN WATER TUBE STEAM GENERATORS." A
communication from abroad by Charles Ward, of Charleston, Kanawha County, State
of Virginia, United States of America.
This Invention is an improvement in the class of boilers or steam generators
formed of concentric or other coils of tubes, through which the water circulates in a
continuous round, and the Invention consists in the construction and arrangement
of parts, as hereinafter described.
In the accompanying Drawing Figure 1 is mainly a sectional elevation of the
improved generator; Figure 2 is a plan view; Figure 3 is a detail cross section on
linex of Figure 1; Figure 4 is a plan view of several different forms of coils or
rings of tubes. The main parts of the generator proper are an outer coil or con-
nected series of pipes A, the corresponding or similar inner coil or series A', the
stand pipes B, B, and the vertical separating drum or cylinder C. The two coils
or series of pipes A, A¹, are concentrically arranged and enclosed by a concentric
iron casing D, having a fire brick lining E. The inner series A¹ also surround a
vertical cylinder F, having a facing of fire brick. Each coil A or A' consists of two
series of parallel inclined tubes a and b, which are joined to the two vertical tubular
connections or stand pipes B, B₁. The latter are placed on opposite sides of the
complete coil, and the tubes a, b, extend from the one to the other, to both of
which they are connected by suitable joints. The stand pipes B, B¹, are set on the
division wall G of the fire box, and thus serve to support the whole system of pipes
or coils. The flame and gaseous products of combustion pass up from each portion
of the fire box in the several annular spaces between the fire brick casing E and
outer coil A, between the two coils A, A', and between the inner coil A¹ and fire
brick post or cylinder F. Thus the fire brick surfaces E and F radiate heat on the
outer and inner coils respectively, and the flame and heat act on them from the
space within, so that fuel is economised and steam generated rapidly.
The manner of connecting the coils or systems of pipes A, A', with the drum or
cylinder C is as follows:-The drum C is provided with two pairs of horizontal
tubular arms I, I, the two of each pair projecting on opposite sides near the top
and bottom. The two stand pipes B which are nearest the drum C are connected
at the bottom with the lower arms I of the drum by curved tubes K and K¹
respectively, while the stand pipes B¹, which are farthest from the drum, are
similarly connected with the upper arms I¹ by tubes L, L'; thus the lower portion
of the separating cylinder C is in communication with the lower ends of one pair of
stand pipes, and the upper end in communication with the upper ends of the other
stand pipes. From this arrangement it results that when the proper degree of heat
has been attained the water in the tubes a, b, becomes expanded and in part con-
verted into steam, so that a circulation sets upward in all the tubes a, b, of both
systems or coils A, A1, from the stand pipes B towards the stand pipes B¹, where
the slow moving currents mingle into one, which flows upward to the top of the
latter, and there divides into currents that pass through tubes L, L', to the arms I¹,
and thus enter the upper portion of the cylinder C. The water is separated from
the steam immediately upon entering the cylinder C, since the water falls by its
own gravity into the main body of cooler water in the lower part of the cylinder.
The steam is taken from the upper portion of the cylinder by pipe e, but to prevent
the water which discharges through pipes L, L, from following the course of the

page_text: steam I interpose a perforated or wire gauze screen M between such pipe and the
arms I. Said screen is arranged horizontally, and attached to the sides of the cylinder.
As the heated water rises in the tubes a, b, its place is supplied by the cooler and
heavier water flowing from the cylinder C through pipes K, K¹, which becoming
heated in turn ascends through stand pipes B¹, and is finally delivered into the
cylinder by pipes L, L', and arms I', and thus the circulation goes on in a continuous
round, the action depending on the difference in gravity between the hot water in
the systems of pipes A, A¹, and the cooler body of water in the cylinder. When
the hot water discharges from arms I¹ into the cylinder and mingles with the colder
water therein the slower motion of the current through the latter (owing to its
increased diameter) favors the deposition of mud or sediment, which is collected in
the bottom of said cylinder, and may be removed therefrom by a discharge
cock. Feed water may be supplied to the cylinder C at any convenient point.
The connections of the pipes K, K', and L, L³, with the cylinder C are such that
they may be readily detached. Thus each system of coil or pipes A or A¹ may be
removed when necessary for the purpose of repair or other reason, and the use of
the other continued the same as before.
There may be any desired number of coils or concentric series of tubes A, A¹.
The tubes a, b, of such coils may be round, square, oval, or of any other form in
cross section; thoy may also have various curves or angles instead of being con-
centric; for example, they may have any of the forms represented in Figure 4.
The coils or systems of pipes A, A, B, B¹, may be set at various angles or in various
positions, as circumstances or judgment may dictate; for example, they may be
inclined at an angle of 40°, or even placed horizontal, but I propose to preserve in
all cases the inclination of the tubes a, b, and their connection with pipes B, B.
In Figure 5 is shown a modification, in which the furnace-dividing wall G is
dispensed with, and the manifolds or arms I are placed beneath the grate within
the fire box. The stand pipes c, c, c', c¹, extend down to and connect with the
arms I, so that the latter support the boiler or systems of tubes in place of the
dividing wall G, as heretofore. The advantages of this arrangement in respect to
economy of fuel, material, and space are obvious.
Having described the nature of the Invention, and the manner of performing the
same, I declare that what I claim as the Invention to be protected by the herein-
before in part recited Letters Patent is,―
1st. In a water tube steam generator the series or systems or coils of inclined
tubes a, b, in combination with pipes B, B', with which the respective ends of said
tubes are connected, substantially as and for the purpose hereinbefore set forth.
2nd. In a water tube steam generator the arrangement of a series of annular or
curved tubes a, b, placed inclined, and connected at their lower ends with an upright
tube which is closed at the top, and at their upper ends with another upright tube
which is closed at the bottom, said upright tube being respectively connected at
bottom and top with the settler or cylinder C by means of pipes, as shown and
described, for the purpose specified.
3rd. In a water tube steam generator the series of pipes or tubes consisting of
parallel tubes a, b, and the vertical stand pipes or connections B, B¹, and a vertical
cylinder with which such stand pipes are connected at top and bottom, all arranged
as shown and described for the purpose specified.
4th. The combination of the coils A, A¹, the inner fire brick cylinder, and outer
casing having a fire brick lining, all said parts being concentrically arranged and
placed at a suitable distance apart to allow the flame and products of combustion
free passage between them, all as shown and described.
5th. The combination of the bridge, wall, or dividing partition of the fire box and
the coils A, A¹, having stand pipes B, B¹, which rest on such wall and support the
coils, all as shown and described.
6th. I also claim the introduction of a perforated plate or screen in the settler
above the arms I' to prevent steam carrying water into exit pipe.

page_text: 7th. I claim placing the manifolds or arms I beneath the grate, so that the same
support the boiler proper (by means of the stand pipes which connect with them),
as shown and described.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Eighth day of April, in the year of our Lord One
thousand eight hundred and eighty.
AT
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A. M. CLARK. (S.)