IMPROVEMENTS IN THE FIRE-BOXES OF LOCOMOTIVE AND OTHER BOILERS AND FURNACES OF SIMILAR CONSTRUCTION."
Year: 1880

page_text: "
PROVISIONAL SPECIFICATION left by Alfred Dowle Street at the Office
of the Commissioners of Patents on the 2nd December 1880. A communi-
cation from abroad by James Knight Street, of Camden, New Jersey, United
States of America.
ALFRED DOWLE STREET, of Notting Hill, in the County of Middlesex.
IMPROVEMENTS IN THE FIRE-BOXES OF LOCOMOTIVE AND OTHER BOILERS AND
FURNACES OF SIMILAR CONSTRUCTION." A communication from abroad by James
Knight Street, of Camden, New Jersey, United States of America.
This Invention relates to improvements in the fire-boxes of locomotive and
other boilers and furnaces of similar construction in order to economise fuel
and reduce the escape of smoke from the chimneys of such furnaces to a
minimum.
For this purpose, within the fire-box (or chamber of the furnace) a hollow
metallic portable diaphragm or draft-plate is mounted of the same radius or sweep
as the top half of the fire-box door, and fitting immediately above the door,
extending inwards and downwards (at an angle of about 30 degrees) to the vertical
centre line of the fire-box.
The said diaphragm or draft-plate is supplied with water from the boiler by
means of pipes leading from its upper surface to the walls or roof of the fire-box,
as may be found most convenient.
This diaphragm or draft-plate is held in position by suitable supports, and
the joints in the connecting pipes are made in the best and most durable
manner.
Another hollow metallic portable diaphragm or combustion arch is mounted
within the fire-box, extending the full breadth of the fire-box, one end of it resting
and fitting against the tube plate below the bottom row of tubes, and extending
upwards and inwards so that it shall overlap the other diaphragm or draft plate
previously described, and resting upon studs fixed into the side walls of the fire box
or otherwise.
The said diaphragm or combustion arch is of arched form, and its upper end is
bent downwards at right angles or thereabouts towards the other or lower diaphragm,
and so that the centre part of the part bent downwards shall be cut or formed to
the same sweep or radius as the upper part of the last described diaphragm, a space
being left between them,

page_text: The said diaphragm or combustion arch is supported and supplied with water in
like manner to the lower diaphragm, as previously described.
By this improved arrangement and construction of fire box or furnace fuel is
economised and the escape of smoke from the chimney reduced to a minimum.
This is effected, first, by burning an inferior quality of coal, as the small coal is not
allowed to pass through the tubes into the smoke box, its passage in that direction
being reduced to a minimum; second, by the gases escaping from the coal being
held in suspension and mixed with air supplied through the furnace door (which
can be kept open without the cold air striking against the tube-plate) they are to
a very great degree consumed before leaving the fire-box; third, by exposing
greater heating surface to the action of the fire, the said diaphragms acting like
two independent small boilers.