Apparatus for Supplying Furnace Fires with Moistened Air.
Year: 1888

page_text: Apparatus for Supplying Furnace Fires with Moistened Air.
WE ROBERT LE LAS and ALBERT ROBIN, both of 23 Boulevard de Strasbourg Paris
France Engineers do hereby declare the nature of this invention to be as follows:-
In furnaces especially such as are supplied with a forced draught the combustion of
the fuel takes place at a high temperature, which is very destructive of the furnace
bars unless they are kept cool. This has sometimes been effected by circulation of
water in contact with the fire bars.
According to the present invention the furnace bars are kept cool by causing the
forced air draught to pass on its way to the furnace through apparatus whereby it is
moistened. The moisture in this moistened air in coming in contact with the heated
bars becomes vaporised and this lowers the temperature of the bars.
In carrying this invention into practice we prefer to use apparatus of the following
kind
..
Air is forced by a blower into a chamber where it comes in contact with a falling
sheet or shower of water before passing into a chamber leading to the ashpit under the
furnace. The furnace bars are preferably of several pieces of sheet iron of deep
vertical section bolted together and kept at a small distance apart by washers interposed
between the successive sheets.
These bars are placed in the furnace grate in the usual manner resting on transverse
supports. The doors of the furnace are preferable made double with a space through
which a regulated portion of the moist air is caused to pass from the chamber
supplying the forced draught, thus keeping the doors cool.
Dated this 13th day of April 1888.
ABEL & IMRAY,
Agents for the Applicants.

page_text: Apparatus for Supplying Furnace Fires with Moistened Air.
We, ROBERT LE LAS, and ALBERT ROBIN, both of 23 Boulevard de Strasbourg,
Paris, France, Engineers, 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 :-
In furnaces, especially such as are supplied with a forced draught, the combustion
of the fuel takes place at a high temperature which is very destructive of the furnace
bars unless they are kept cool. This has sometimes been effected by circulation of
water in contact with the fire bars.
According to the present invention, the furnace bars are kept cool by causing the
forced air draught to pass on its way to the furnace through apparatus whereby it is
moistened. The moisture in this moistened air in coming in contact with the heated
bars becomes vaporised and this lowers the temperature of the bars.
In carrying this invention into practice we prefer to use apparatus such as we shall
describe referring to the accompanying drawings.
The
Fig. 1 is a longitudinal section of a boiler with fire grate adapted for working
according to our invention. Fig. 2 is an end view of double flued boiler with vertical.
section of the air moistening apparatus. A current of air caused by a fan V passes
through the moistening apparatus and conduit D to removeable,boxes B placed in front
of the ashpits, whence it passes up through the fire bars of the grate G.
moistening apparatus may be variously arranged. For marine boilers, the arrangement
shewn in Fig. 2 is preferable because its action is not disturbed by motion of the
vessel. The air current is sent down by the bent pipe T into a lattice chamber E in
which falls in showers water supplied by the pipe t. The air in passing through the
water showers takes up moisture which it carries with it up the casing C to the
conduit D and thence to the fires. The surplus water passes away by a pipe . The
chamber E is preferably of lattice work or large mesh metal gauze holding water in
the interstices through which the air has to pass. For land boilers the arrangement
shewn in Fig. 3 is suitable. While the air passes upwards from F through U to D,
water supplied by the pipet falls in a shower from a perforated plate G through which
the air passes. Fig. 4 is a transverse section and Fig. 5 a side view of one of the fire
bars X which consists of a number of thin plates very deep in the middle, kept apart
by distance washers and held together by rivets e. Owing to the depth of these bars
and their subdivision into laminae, the moist air has to pass over a very extended
surface. These bars are supported as usual on transverse bearing bars s., In order to
promote combustion of smoke, we prefer to provide a narrow slit forming a passage f
from the box B to the space between the two plates of the fire door, so that a certain
amount of air determined by a valve at f, whilst it keeps the fire door and dead plate
cool, becomes heated and assists in consuming smoke. For marine boilers worked by
forced draught the fan should draw from the engine room or stoke-hole, promoting its
cooling and ventilation.

page_text: Where there is a range of land boilers, a pump or blower may be used instead of a
fan to produce forced draught.
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. Supplying furnaces with forced draught of air previously moistened, as and for
the purpose set forth.
2. For the purpose of moistening the air, causing the air current to pass on its way
to the fires through a wetted screen or shower of water, substantially as described.
3. For fire grates supplied with moistened air, the construction of bars of thin
lamine and great depth, as and for the purpose set forth.
4. Admitting at the dead plate through a double fire door a regulated supply of
moistened air, in order to cool the metal and promote combustion of smoke as herein
described.
1
T
1
T
1000