Improvements in and connected with the Furnaces of Water-tube Steam Boilers.
Year: 1890

page_text: Date of Application, 12th Apr., 1890
Complete Specification Left, 8th Jan., 1891-Accepted, 14th Feb., 1891
PROVISIONAL SPECIFICATION.
Improvements in and connected with the Furnaces of Water-tube
Steam Boilers.
We, JAMES RILEY, General Manager to The Steel Company of Scotland,
Limited, of 23 Royal Exchange Square, Glasgow, in the County of Lanark,
North Britain, and EDWARD JAMES DUFF, of 118 Ingleby Drive, Glasgow,
aforesaid, Engineer, do hereby declare the nature of this invention to be as follows,
that is to say :-
Our said invention has for its object to increase the efficiency of the furnaces of
water-tube steam boilers and to prevent smoke.
We apply our improvements according to one modification to a boiler comprising
a number of inclined water tubes fixed in end casings which are connected to one
or more upper drums or cylinders, the arrangements being such that the water
circulates through the tubes entering at their lower ends and passing from their
upper ends into the upper cylinder or cylinders. We form a grate of longitudinal
water tubes of smaller size than the main water tubes, the inner ends of these grate
tubes being by preference higher than their outer ends. The grate tubes are fixed
in end casings which are connected by pipes to the main boiler in a manner to cause
water to circulate through the grate tubes.
The space under the grate tubes is divided by a transverse partition into an
outer space from which air passes up between the tubes and through fuel lying on
them, and an inner space which latter is in direct communication with the flue
leading from the furnace. The fuel is placed on the grate tubes so as to extend
inwards beyond the position of the partition beneath, but a space is provided at the
inner end of the furnace such that a portion of the fire gases can pass freely down-
wards either between the grate tubes at and near their inner ends, or beyond their
inner ends. Directly over the grate tubes some of the lower main water tubes of the
boiler, are for a part of their length, exposed to the action of the fire; but a firebrick
partition which is transversely horizontal but inclined longitudinally is placed between
the lower and upper main water tubes; and at the inner end of this partition there
is a nearly vertical firebrick partition or wall descending to the level of the inner ends
of the grate tubes or nearly so. The two partitions enclose a space over the grate
tubes and the fire gases proceed from the space under the nearly vertical partition
partly through the incandescent fuel on the inner parts of the grate tubes and partly
through the space at the inner ends of the grate tubes. Thence the fire gases
proceed upwards amongst the main water tubes at the further or inner side of the
nearly vertical partition, and next pass along the main water tubes over the other
or transversely horizontal partition to flues leading them in contact with the upper
cylinder or cylinders.
The fire gases having to descend and pass under the nearly vertical partition at
the inner end of the furnace are thereby made to pass in close contact with, and
partly through the incandescent fuel at the inner part of the furnace, with the
result that the combustible constituents of the gases are completely ignited, their
efficiency increased and smoke prevented.
Dated this Eleventh day of April 1890.
EDMUND HUNT,
Applicants' Agent.

page_text: COMPLETE SPECIFICATION.
Improvements in and connected with the Furnaces of Water-tube
Steam Boilers:
We, JAMES RILEY, General Manager to The Steel Company of Scotland,
Limited, of 23, Royal Exchange Square, Glasgow, in the County of Lanark,
North Britain, and EDWARD JAMES DUFF, of 118 Ingleby Drive, Glasgow,
aforesaid, 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, that is to say:—
Our said invention has for its object to increase the efficiency of the furnaces of
water-tube steam boilers and to prevent smoke.
The application of our improvements according to one modification is shown on
an accompanying sheet of explanatory drawings, Figures 1, and 2, of these
drawings being respectively transverse and longitudinal vertical sections. The
section in Figure 1, is at the line A B C D E F, in Figure, 2.
The boiler represented in the drawings comprises a number of inclined water
tubes, 3, fixed in end casings, 4, 5, which are connected to an upper drum or
cylinder, 6, the arrangements being such that the water circulates through the
tubes, 3, entering at their lower ends and passing from their upper ends into the
upper cylinder, 6. We form a grate of longitudinal water tubes, 7, of smaller size
than the main water tubes, 3, the ends of these grate tubes, 7, being fixed in
casings, 8, 9, which are connected by pipes, 10, 11, to the end casings, 4, 5, of the
main water tubes, 3, in a manner to cause water to circulate through the grate
tubes, 7.
The space under the grate tubes, 7, is divided by a transverse partition, 12, into
an outer space, 13, from which air passes up between the tubes and through fuel
lying on them, and an inner space, 14, which latter is in direct communication with
the flue or passage leading from the furnace. The partition, 12, is provided with a
door to give access for removing ashes from the space, 14.
The fuel is placed on the grate tubes, 7, so as to extend inwards beyond the
position of the partition, 12, beneath, but a space, 15, is provided at the inner end
of the furnace, such that a portion of the fire gases can pass freely downwards
either beyond the inner ends of the grate tubes, 7, as shown in Figure, 2, or between
those tubes at and near their inner ends.
Directly over the grate tubes, 7, some of the lower main water tubes, 3, of the
boiler, are for a part of their length, exposed to the action of the fire; but a fire-
brick partition, 16, consisting of parts which are transversely horizontal but
inclined longitudinally and are connected by nearly vertical parts to each other
and to a hanging bridge, 17, at the inner end of the furnace. The partition, 16,
and bridge, 17, enclose a space over the grate tubes, 7, and the fire gases proceed
from this space under the hanging bridge, 17, partly through the incandescent fuel
on the inner parts of the grate tubes, 7, and partly through the space, 15, at the
inner ends of the grate tubes. Thence the fire gases proceed upwards amongst the
main water tubes, 3, between the partition, 16, and a second partition, 18, and after
passing along to the upper ends of the upper main water tubes, return under the
cylinder, 6, over the partition, 18. From the space above the partition, 18, the
fire gases descend again amongst the main water tubes, and passing under a nearly
vertical partition, 19, rise again and pass over the lower end casing, 4, to the
chimney.
The fire gases having, in the furnace, to descend and pass under the hanging
bridge, 17, at the inner end, are thereby made to pass in close contact with and partly
through the incandescent fuel at the inner part of the furnace, with the result that
the combustible constituents of the gases are completely ignited, their efficiency
increased and smoke prevented. By providing the comparatively free space, 15, at
the inner end of the furnace for the downward passage of a portion of the fuel

page_text: gases, there is avoided the great resistance to the flow of the gases which has been
the cause of inefficiency in attempts to make the whole of the fuel gases pass
downwards through fuel.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is-
1. The combination of parts constituting the improved water-tube steam-boiler
furnace arrangements substantially as hereinbefore described and shown in the
accompanying drawings.
2. In a water-tube steam boiler, the combination of a water-tube grate, a hanging
bridge closing the inner end of the space above the grate, a partition separating an
outer part of the space under the grate from an inner part communicating with the
flue or passage for the fire gases, and a space at the inner end of the grate for the
free passage of a portion of the fire gases, all arranged substantially as herein before
described.
Dated this Seventh day of January 1891
EDMUND HUNT,
Applicants' Agent.