IMPROVEMENTS IN STEAM AND OTHER BOILERS
Year: 1878

page_text: LETTERS PATENT to Samuel Thacker, of the Town and County of the Town
of Nottingham, Engineer, for the Invention of "IMPROVEMENTS IN STEAM AND
OTHER BOILERS."
Sealed the 25th October 1878, and dated the 23rd August 1878.
PROVISIONAL SPECIFICATION left by the said Samuel Thacker at the
Office of the Commissioners of Patents on the 23rd August 1878.
SAMUEL THACKER, of the Town and County of the Town of Nottingham,
Engineer. "IMPROVEMENTS IN STEAM AND OTHER BOILERS."
The Invention has for its object improvements in steam and other boilers. For
this purpose I place the furnace at or near the top of the water instead of under-
neath the saine, as has heretofore been the practice, and I cause the flame and pro-
ducts of combustion to descend through the grate bottom, and in vertical boilers to
be distributed by a water chamber made the full width of the boiler, and dividing
the interior of the same, so as to cause the flame and products of combustion to pass
first along the one side, around the end, and then along the other side of such water
space before passing away to the fluc
I form the boiler of two shells with a water space between them, and the interior
space I traverse with tubes connecting the water space on the one side with that on
the other.
In the passage of the products of combustion through the boiler, the water in the
tubes and in the divisional water space is heated thereby.
The fire-grate or furnace bottom I sometimes form of a water chamber communi-
cating with the water space between the shells of the boiler, and I pass tubes
through such hollow furnace bottom to allow of the products of combustion passing
therethrough. These Inst-mentioned tubes I prefer to make taper, with the smaller
end at the top, so as to facilitate the passage and clearance away therefrom of any
cinder or clinker which may pass into the same; or I use tubular or hollow fire-bars
communicating with the water spaces of the boiler.

page_text: The steam dome or chamber is placed above the furnace bottom, and commu-
nicates therewith and with the space between the shells of the boiler, which latter
are continued above the furnace bottom to form the sides of the furnace.
The fire is lighted on the top, and the fuel is fed on to the top of the fire as
usual, but the flame passes down through the furnace bottom instead of upwards
through the fuel.
•
By these means perfect combustion of the fuel is obtained, and consequently no
smoke is allowed to escape from the furnace.
For horizontal boilers a similar arrangement of parts is employed, with suitable
modifications in form and direction to suit this description of boiler. In this case
the furnace is placed at one end and at the upper part of the boiler, and the flame
and products of combustion pass downwards into and along a flue formed in the
body of the boiler, and extending to or nearly to the opposite end thereof, and
then returning to the furnace end, where the products of combustion pass away into
the exterior flue, which may be carried along the sides of the boiler. A water space
divides the two parts of the interior flue, and water tubes passing through or across
the flue connect the water spaces above and below the interior flue with the central
divisional water space, thereby assisting circulation of the water and the absorption
of heat from the products of combustion.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Samuel Thacker in the Great Seal Patent Office on the 22nd February
1879.
SAMUEL THACKER, of the Town and County of the Town of Nottingham,
Engineer. "IMPROVEMENTS IN STEAM AND OTHER BOILERS,"
The Invention has for its object improvements in steam and other boilers. For
this purpose I place the furnace at or near the top of the water instead of under-
neath the same, as has heretofore been the practice, and I cause the flame and pro-
ducts of combustion to descend through the grate bottom, and in vertical boilers to
be distributed by a water chamber made the full width of the boiler, and dividing
the interior of the same, so as to cause the flame and products of combustion to pass
first along the one side, around the end, and then along the other side of such water
space before passing away to the flue.
I form the boiler of two shells with a water space between them, and the interior
space I traverse with tubes connecting the water space on the one side with that on
the other.
In the passage of the products of combustion through the boiler, the water in the
tubes and in the divisional water space is heated thereby.
The fire-grate or furnace bottom I sometimes form of a water chamber commu-
nicating with the water space between the shells of the boiler, and I pass tubes
through such hollow furnace bottom to allow of the products of combustion passing
therethrough. These last-mentioned tubes I prefer to make taper, with the smaller
end of the top, so as to facilitate the passage and clearance away therefrom of any
cinder or clinker which may pass into the same; or I use tubular or hollow fire-bars
communicating with the water spaces of the boiler.
The steam dome or chamber is placed above the furnace bottom, and commu-
nicates therewith and with the space between the shells of the boiler, which latter
are continued above the furnace bottom to form the sides of the furnace.
The fire is lighted on the top, and the fuel is fed on to the top of the fire as usual,
but the flame passes down through the furnace bottom instead of upwards through
the fuel.
By these means perfect combustion of the fuel is obtained, and consequently no
smoke is allowed to escape from the furnace.
For horizontal boilers a similar arrangement of parts is employed, with suitable
modifications in form and direction to suit this description of boiler. In this case
the furnace is placed at one end and at the upper part of the boiler, and the flame
and products of combustion pass downwards into and along a flue formed in the
body of the boiler, and extending to or nearly to the opposite end thereof, and
then returning to the furnace; and where the products of combustion pass away into
the exterior flue, which may be carried along the sides of the boiler, a water space
divides the two parts of the interior flue, and water tubes passing through or across
the Bue connect the water spaces above and below the interior flue with the central
divisional water space, thereby assisting circulation of the water and the absorption
of heat from the products of combustion.
And in order that my said Invention may be more clearly understood and readily
carried into effect, I will proceed, aided by the accompanying Drawings, more fully

page_text: Figure 4 is a partial vertical section representing my improved boiler with a
different construction of grate.
Figure 5 is a cross section on the line 3, 3, of Figure 6, which latter is a longitu-
dinal section of a horizontal boiler with my Invention applied thereto.
In all the Figures like parts are marked with similar letters of reference.
Upright boilers constructed according to my Invention may be of circular section,
with a square or rectangular fire-box, but I preferably construct them rectangular
or square throughout, as represented in the accompanying Drawings at Figures 1
to 4 inclusive.
The boiler is formed with an outer shell a and an inner shell b secured and
rivetted together, as represented in the Drawings, or in other convenient and
effectual manner. The inner shell 6 terminates with a suitably shaped fire-hole c
at the top of the boiler, which may be provided with any suitable door or cover as
may be found desirable. The boiler is also fitted with apertures and air-tight doors,
one marked & being placed immediately above the grate to facilitate the cleaning
out of the fire, the other marked e being placed at the bottom of the boiler for the
purpose of enabling the ashes to be removed when required.
A diaphragm f made in the form of a flat tubo runs transversely across the inner
shell b; this diaphragm is so constructed as to have an internal water space, whereby
the heating surface of the boiler is greatly increased; it is well stayed with copper
rivets or stays, as will be well understood.
Brass or other tubes g run across the inside shell, connecting the water spaces on
opposite sides of the boiler together, water passing through such tubes; by these
means the heating surface of the boiler can be greatly extended.
The tubes g are screwed at one end, and put through clear holes in the outer
shell; they are then screwed into one side of the inner shell, and expanded to fit
steam-tight into the opposite side of the inner shell. The hole in the outer shell is
afterwards tapped to receive a scrow plug h; these plugs h have to be withdrawn to
clean out the tubes and to replace them.
In the arrangement represented at Figures 1, 2, and 3 the grate or fire-bars are
formed of water tubes i, which are reduced at one end to leave sufficient strength
of boiler plate between them; or they may be of equal diameter throughout, and
thicker boiler plates used. These tubes i are screwed into the inner shell of the
boiler at the one end, and are expanded to fit steam-tight at the opposite end, and
they are inclined to the horizontal to facilitate circulation of the water there-
through.
Immediately over and resting on the tubes i are placed loose or moveable bars of
metal or fire-brick ¹ to protect the water tube bars against accident when raking
out the fire.
The fire-bars i are in a suitable position above the diaphragm plate, and at or
near the top of the water in the boiler.
The uptake or flue for taking away the products of combustion is placed on
the opposite side of the diaphragm to that on which the products of combustion
first act.
In the arrangement represented at Figure 4 the grate shown is formed of a water
chamber communicating by tubes with the water spaces between the shells a, b,
of the boiler, and I pass tubes through such hollow furnace bottom j to allow of
the products of combustion passing therethrough. These tubes I prefer to form
taper, with the smaller end at the top, so as to facilitate the passage and clearance
away therefrom of any cinder or clinker which may pass into the same.
Immediately above the fire-bars or grate, and below the same, communicating
with the flue, are placed short tubes k communicating with the atmosphere and the
fire to admit air to ensure perfect combustion.
The boiler may be set upon a bed plate or upon masonry, as desired.
The action of boilers such as those represented at Figures 1 to 4 is as follows:-
The space below the grate being divided into two chainbers by the diaphragm, and
the fire made on the fire-bars or grate, and the lower chamber being in connection

page_text: with the chimney, a current of air would be immediately caused to descend through
the fuel, the heat and products of combustion would pass downwards round and
across some of the tubes g, and would play on the sides of the inner shell b and on
one side of the diaphragm; they would then turn round the bottom end of the dia-
phragm, and would rise to and pass away by the outlet, and in doing so would net
upon the second side of the diaphragm, as also upon other of the tubes g and upon
the sides of the inner shell b.
In applying my Invention to horizontal, Lancashire, Cornish, or tubular boilers,
and as represented at Figures 5 and 6, which are respectively a cross section and a
longitudinal section of a horizontal boiler constructed according to my Invention, I
place the fire-grate in a vertical, rectangular, or square fire-box l, and the flame and
products of combustion pass downwards through the firo-bars or through the hollow
grate, as the case may be, and along a flue m formed within the body of the boiler,
and extending to or nearly to the opposite end thereof, and then returning to the
front or furnace end of the boiler, where the products of combustion pass away
through the outlet aperture into the exterior flue, which may be carried along the
sides and underneath the boiler; a water space or diaphragin f divides the two parts
of the flue m, and water tubes n passing through or across the flue m connect tho
water spaces above and below the flue m with the central divisional water space or
diaphragm f, thereby assisting circulation of the water and the absorption of heat
from the products of combustion as the latter pass across and around the tubes n in
the passage through the fluo m.
The flue m is formed of the shell b and the sides of the central divisional water
space f, and I would remark that the flue m may, if desired, be extended so as to
return again to the rear end of the boiler, and, if desired, back again, suitable water
spaces or diaphragms being employed as required, suitable internal supports being
employed to secure the flues m in position.
In boilers constructed according to my Invention ignition takes place above the
grate, and the products of combustion pass downwards through the intense heat of
the fire, whoreby complete combustion is effected.
Having thus described the nature of my said Invention, and the mode in which
I carry the same into effect, I would have it understood that what I claim is, the
peculiar combination and arrangement of parts of steam and other boilers, substan-
tially as berein shown and described.
In witness whereof, I, the said Samuel Thacker, have hereunto set my hand and
seal, this Twentieth day of February, in the year of our Lord One thousand
eight hundred and seventy-nine.
SAM THACKER. (LS.)