Improvements in Water Tube Boilers.
Year: 1898

page_text: .
PROVISIONAL SPECIFICATION.
Improvements in Water Tube Boilers.
I, WILLIAM KNEEN, of 17, Coleman Street, in the City of London, Mechanical
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to boilers of the water-tube class, such as those known as
Babcock boilers for example, wherein water tubes are disposed over or around
the fire and it has for its object to provide means whereby a thorough combustion
of the fuel is effected by the mixture of atmospheric air with the products of com-
bustion either immediately before or after they have passed between the tubes.
For this purpose to each of the said tubes forming the lower or innermost row of
tubes, and if desired, also to those of a row or rows above them or outward of them,
I apply air pipes with apertures through which air can be forced for example by a
fan or blower, or a steam jet. The said pipes are preferably made saddle-shape
so as to seat snugly against the water tubes and the apertures in the said pipes may
be in one row or in two or more rows, or be otherwise disposed in the said pipes,
which should be parallel with the water-tubes and extend over the area through
which the products of combustion pass, from the furnace. The said air pipes may
be attached either below the water tubes or above them or at the side or sides
thereof, but I prefer to mount them above the water-tubes or on the side opposite
the fire.
The air to be supplied to the pipes may be previously heated for which purpose
the lower ends of the air pipes may be attached to an air chamber immediately
behind the bridge or wall in the case of the boiler known as the Babcock boiler,
a main air pipe being attached to the said chamber by means of which air is con-
veyed from the fan or blower.
By these means air is conveyed to the products of combustion and thoroughly
mixed with them in finely divided jets over the whole of the body of the said pro-
ducts immediately after they leave the fuel in the furnace.
The invention may be applied to boilers in which the water-tubes are in a hori-
zontal or vertical position or otherwise disposed.
Creasole, tar, petroleum, or other liquids of a hydrocarbon character may be
mixed with solid fuel of a cheap character and consumed effectually in the herein
described furnace by increasing the pressure of air ordinarily supplied by the fan
or blower so as to meet the chemical requirements of the extra gas arising from
the liquid fuel in combination with the solid fuel.
Dated this 23rd day of July 1898.
JOHNSONS & WILLCOX.
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in Water Tube Boilers.
I, WILLIAM KNEEN, of 17, Coleman Street, in the City of London, Mechanical
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement:-
My invention relates to boilers of the water tube class such as those known as
Babcock boilers, for example wherein water-tubes are disposed over, or around the
fire; and it has for its object to provide means whereby a thorough combustion
of the fuel is effected by the admixture of atmospheric air with the products of
combustion, either immediately before, or after, they have passed between the
tubes, or as they pass between them. For this purpose to each of the said tubes
forming the lower, or innermost, row of tubes and, if desired, also to those of a row,
or rows, above them, or outward of them, I apply air pipes with apertures therein
through which air can be forced by any suitable device, such for example as a
fan, blower, or steam jet. The said pipes are preferably made saddle shape" so
as to seat snugly against the water tubes and the apertures in the said pipes may
be in one row, or in two, or more rows, or be otherwise disposed in the said pipes.
I will describe with reference to the accompanying drawings an arrangement
according to my invention premising however that I do not limit myself to the
precise arrangement of details shewn.
Figures and 2 are vertical sections at right angles to each other of part of a
Babcock hoiler and furnace to which my invention is applied. The section Figure 1
is taken on the line 1, 2, Figure 2. Figure 3 is a transverse section of some of the
water tubes shewing (to a larger scale) the air pipes applied thereto. A are the
water tubes and the furnace. To each of the water tubes of the lower row is
applied an air pipe C, shaped at bottom to seat upon the water tube and lie thereon
parallel therewith, and extending the length of the passages through which the
products of combustion pass from the furnace. The said air pipes are perforated
at c. They may be attached below the water tubes or at the side or sides thereof
instead of above them as shewn or they may even be placed transversely of the
water tubes but I prefer to arrange them as shewn in the drawings. The air is
supplied to the pipes by any suitable air forcing device. In the arrangement
shewn in the drawing the lower ends of the air pipes are connected by the pipes I),
passing through the bridge, or wall, with an air chamber E immediately behind
the bridge or wall a main air pipe e being attached to the said chamber E by which
air is conveyed from the air forcing device. By these means air is conveyed to
the products of combustion in finely divided jets and thoroughly mixed with them
throughout their whole extent immediately after they leave the fuel in the furnace
and on their way between the water tubes. The invention may be applied to boilers
in which the water-tubes are in a horizontal or a vertical position or at some inter-
mediate angle.
Creosote, tar, petroleum, or other hydrocarbon liquids may be mixed with cheap
solid fuel and be effectually consumed in a furnace provided with my invention
by increasing the pressure of air ordinarily supplied by the air forcing device so
as to meet the chemical requirements for the consumption of the extra gas arising
from the combined líquid and solid fuel. The pipes C, and the pipes D (or so
much of them as is exposed to great heat) are preferably made of plumbago after
the manner in which plumbago crucibles are made.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what I
claim is;-
1. In water tube boilers, of the character referred to the combination with the
lower or inner tubes of perforated air pipes and an air forcing device the said
air pipes being so arranged as to cause the air issuing therefrom to meet the pro-
ducts of combustion from the fire immediately before, or whilst, or after, they pass
between the water tubes substantially as herein before described.
2. In water tube boilers of the character referred to, the combination with the
lower, or inner tubes, of perforated air pipes made to fit upon, or against, the tubes,
and connected by pipes, or passages, with an air box, or channel, into which air
is forced substantially as hereinbefore described.
Dated this 29th day of February 1899.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.