IMPROVEMENTS IN STEAM GENERATING FURNACES AND IN STEAM HEATING APPARATUS
Year: 1875

page_text: PROVISIONAL SPECIFICATION left by Joshua Kidd at the Office
of the Commissioners of Patents, with his Petition, on the 8th
December 1875.
I, JOSHUA KIDD, of No. 12, Dartmouth Street, Westminster, Gas
Engineer, do hereby declare the nature of the said Invention for
." IMPROVEMENTS IN STEAM GENERATING FURNACES AND IN STEAM HEATING
APPARATUS," to be as follows :—
My first improvement relates to furnaces for generating steam, which
furnaces are also applicable for other purposes, and consists in the novel
application of the steam jet or other blowing apparatus for forcing air
both under, unto, and above the burning fuel.
I am aware that air has before been forced by a jet of steam, and also
by a fan blower into a closed ash-pit and under the fuel, but this arrange-
ment has simply intensified the combustion, or caused the fuel to give

page_text: off gas more rapidly, which gas not being supplied with sufficient
oxygen a large quantity has escaped up the chimney unburned.
.
My improvements consist in connecting to a closed ash-pit an iron or
fire-clay pipe, curved so as to project over the fire, or so arranged as to
form the fire bridge; this pipe must be thickly pierced by small holes
from a quarter to half an inch in diameter, so that when air is forced into
the closed ash-pit it will also be forced through the small holes in the pipe
placed over the fire or forming the fire bridge and supply the necessary
oxygen to thoroughly burn the gases. I also accomplish the same.
result by taking out one or two of the centre fire-bars in a steam furnace
and placing in lieu thereof a long hollow oval or flat cast iron or fire-
clay retort made to project above the fuel and below the fire-bars, the
top of this retort must be thickly pierced with small holes, and a row
of holes should also be made lengthwise in the retort from four to six
inches above the grate bars about midway between the fuel. When
air is forced by a steam jet or by a fan blower into this hollow retort it
will not only force air into the thick mass of fuel, but supply the
necessary air in a finely divided form to burn the gases generated in the
furnace. A steam pipe communicating with the boiler, coiled or other-
wise, should be fixed lengthwise in this retort for superheating the steam
to form the jet for inducing air into the said retort; on the line of the
lower row of holes the retort is made to separate into two halves for
convenience of fixing the superheating pipes; when this retort is used
the ash-pit should be open to the atmosphere.
The second part of my improvements relates to steam boilers and
radiators for heating purposes, and the improvement consists in so
arranging the boilers and radiators that all condensed water will return
to the boiler by its own gravity, the boiler may be made of tin or copper
or other thin sheet metal with solid or hollow projections at the bottom,
and to prevent the steam ever increasing in pressure over about 1lb., I
let the steam pipe dip from 1 foot to 2 feet into a tube or vessel filled
with water, in this way the steam is only held in the boiler by the
water seal, and the pressure can never exceed the weight of the column
of water. A constant level of water may be maintained in the boiler
by means of a float made to actuate a cock, the radiators should be
made of some metal that will not oxydize, such as zinc or copper pipe,

page_text: and the pipes should be fixed with a slight incline towards the boiler, and
with an adjustable air opening to the atmosphere at the highest point
of the radiator, so that air can pass in and out at the top of the radiator
to prevent the formation of a vacuum; if required gas or petroleum may
be burned to generate steam in those boilers.