IMPROVEMENTS IN OR RELATING TO BOILER FURNACES
Year: 1885

page_text: J, CHARLES BYRON DAVISON, residing at Ann Arbor, in the County of Wash-
tenaw, and State of Michigan, in the United States of America, Electrician, do
hereby declare the nature of this invention for IMPROVEMENTS IN OR RELATING
TO BOILER FURNACES". 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 an improvement in Steam Boiler Furnaces, and consists
in the construction and arrangement of the parts, more fully herein after described
and pointed out in the claims.
The object of my invention is to obtain a more perfect combustion of fuel then
has hitherto been accomplished, without material change or alteration of the furnaces-
now in use, and by means simple and inexpensive in construction, and readily.
understood and operated.
A further object of my invention is to consume the smoke and other gases arising
from combustion, thereby doing away with the obnoxious odors, and the incon-
veniences resulting therefrom, and at the same time securing a great saving in the
consumption of fuel.
Many attempts have been made to accomplish these objects, and by a variety
of means and methods, but so far as I have been able to learn with only partial
success.
The failure so to do, has been due to the fact, that certain necessary conditions
have not been observed, and also that the means or methods employed have been
complicated and cumbersome or difficult to carry out.
To secure perfect combustion the following conditions must be observed, viz:
(1) The furnace must be supplied with a sufficient quantity of air to furnish the
needed oxygen.
(2) This air must be thoroughly mixed with the products of combustion arising
from the bed of fuel.
(3) The gases arising from combustion must be kept at a high degree of heat, not
less than 800° Fabr.
These conditions may be maintained, by my improvement, with ease, and entire
uniformity, and when so maintained, perfect, or nearly perfect combustion is
secured.

page_text: I attain these objects by the means shown in the accompaning drawings, forming
a part of this specification, wherein like letters of reference indicates similar parts,
and in which:
Figure 1, is a longitudinal vertical section of a furnace, and a side elevation of a
part of a boiler, showing the steam chamber, and pipes for conducting the steam to
the furnace.
Figure 2, is a front elevation of a furnace and boiler showing the arrangement
and connection of the steam pipes, and the air inlets in the furnace doors and
· Figure 3, is a longitudinal vertical section of a nozzle for the steam pipes in the
furnace.
A, represents a steam boiler set over a furnace and provided with a steam
dome B, C, represents the front wall of the furnace, and D the bridge wall, between
which walls the fire grate E is supported.
The doors II are hinged in the usual manner, and slotted or perforated as shown
at prime K in figure 2, for the purpose of admitting à current of air into the furnace
just over the surface of the fuel, These perforations or slots may be closed in whole
or in parts by suitable registers as desired.
A pipe F connected with the dome B, or the top of the boiler, or any pipe from
the top is brought down in front of the furnace, where it joins a distributing
pipe G, connecting with the branch pipes H, H, for conducting steam into the
furnace.
The pipes H. H, are placed over the doors and are bent at right angles near the
ends, and carried through the front wall, the ends projecting through the wall being
bent at such an angle as to cause the steam forced through them to come in contact
with the current of air coming in through the slots or perforations K. K, about two
thirds of the distance back from the front end of the furnace.
The ends of said pipes are screw threaded on which are screwed the nozzles J.
The nozzle J, is about one and one half inches long, and three fourths of an inch in
diamater at the largest end.
It has a throat 2, from one sixteenths to one twenty fourth of an inch in diamater.
The throat is reduced in diamater, so that the jet, or current of steam, can be more
perfectly regulated. The mouth 3, is hollowed out so that the jets of steam may
spread out and form a sheet reaching from one side of the fire chamber to the other.
By means of this nozzle the steam is brought into the fire chamber with such force,
as to thoroughly agitate the gases arising from combustion, and mix them with the
incoming current of air. The force imparted to said gases also carries them back
along the bottom of the boiler, thus distributing the heat more uniformily and at
the same time greatly increasing the draught. The pipe F is provided with a
cock L, for letting on and shutting off the steam.
The operation of my invention is as follows:-
The fuel on the grate having been brought to an incandescent state, a current of
air is brought into the fire chamber through the slots or perforations in the doors I I,
just above the level of the fuel. The cock L, having been turned jets of steam are
forced into said chamber through the nozzles J J, at such an angle as to strike the
current of air about two thirds the depth of the furnace back from the doors. The
air being heated by passing over the incandescent fuel gives off its oxygen, which
becoming thoroughly mixed with the gases arising from combustion by the jets of
steam, the requisite amount of oxygen is brought in contact with said gases and
the unconsumed particles of carbon, to insure complete combustion.
The force of the jets of steam is such as to drive the heat in the fire chamber
back, under the boiler and thereby better distribute the same.
The fine particles of carbon being consumed, the flues are not clogged thereby.
The draught is greatly improved by the force of the steam; thereby aiding in
the distribution of the heat.
The advantages of my invention, are, (1) simplicity and cheapness of construction
and operation, (2) the facility in which it can be adapted to furnaces now in use,

page_text: (3) its durability (4) the saving of fuel, and consumption of smoke and other gases,
(5) the use of cheaper grades of coal is by it made possible and profitable.
Having thus described my invention, what I claim and desire to secure by Letters
Patent is
1. In a steam boiler furnace, the combination of doors having the slots or per-
forations about on a line with the upper surface of the fuel as described, for the
admission of air into the fire chamber, with steam pipes having distributing nozzles
set at such an angle that the steam forced there through will strike the current of
air coming in through the doors at a point about two thirds the distance back from
Baid doors, substantially as described.
2. In a steam boiler furnace the combination of a pipe leading from the steam
dome, and one or more branch pipes, provided with nozzles extending into the fire
chamber, at such an angle as to bring the current or jets of steam, in contact with
the air entering through alots or perforations in the doors, about on a line with the
upper surface of the fuel, and the gases arising from the combustion, about two
thirds the distance back from the doors, substantially as desired.
3. In a steam boiler furnace, the combination of slotted or perforated doors as
described, steam pipes entering the furnace through the front wall at such an angle
that the steam will come in contact with a current of air coming in through slots
or perforations in the doors about on a line with the upper surface of the fuel,
and the incomplete products of combustion arising from the fuel, about two thirds
of the depth of the furnace back from the front wall, substantially as described.
4. In a steam boiler furnace, the combination of the pipe F, having cock L, dis-
tributing pipe G, branch pipes H. H, nozzles J. J, doors I. I, provided with slots or
perforations K. K, grate E, and front and bridge walls C and D, Constructed and
arranged substantially as described.
· Dated thin on
AL