An Improvement in Down-draught Furnaces and Producers.
Year: 1896

page_text: Date of Application, 7th July, 1896
Complete Specification Left, 5th May, 1897-Accepted, 5th June, 1337
PROVISIONAL SPECIFICATION.
An Improvement in Down-draught Furnaces and Producers.
1, ROBERT MARSHALL of 21 Red Cross Street, Borough, in the County
of London, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to a construction of furnace or producer in which the
air draught passes downwards through the fuel. I provide successive steps like
steps of a stair each step made of fire tiles and the riser of each step open so that
when the steps are covered to a certain depth with fuel the air forced or drawn in
above the steps passes through the fuel, and the products of combustion pass
through the riser behind, and downwards into the space below the steps, whence
they can be led to the flues of a boiler or to the bed of a furnace. In order to
prevent overheating of the tiles which constitute the steps, I arrange under each
step two or more transverse water tubes on which the tiles rest and I arrange
communicatious between the successive tiers of tubes and to and from the
water space of a boiler, so that a circulation of water is maintained through
the tubes.
By closing the space over the steps and forcing in a limited supply of air, the
apparatus can be worked as a gas producer.
Dated this 7th day of July 1896.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in Down-draught Furnaces and Producers.
I, ROBERT MARSHALL, of 21 Red Cross Street, Borough, in the County
of London, 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:-
My invention relates to a construction of furnace or producer in which the
air draught passes downwards through the fuel. I provide successive steps, like
steps of a stair, each step made of fire tiles and the riser of each step open
so that when the steps are covered to a certain depth with fuel the air forced
or drawn in above the steps passes through the fuel, and the products of
combustion pass through the riser behind and downwards into the space below
the steps, whence they can be led to the flues of a boiler or to the bed of a
furnace. In order to prevent overheating of the tiles which constitute the steps,
1 arrange under each step two or more transverse water tubes on which the tiles
rest and I arrange communications between the successive tiers of tubes and to and
from the water space of a boiler, so that a circulation of water is maintained
through the tubes.

page_text: By closing the space over the steps and forcing in a limited supply of air, the
apparatus can be worked as a gas producer.
The accompanying drawing shews a vertical section of a down-draught furnace
or producer constructed according to my above described invention. Within the
combustion chamber A are constructed the steps B B formed cf fire tiles, resting
upon tubes C through which water is made to circulate.
These tubes are carried by the sides of the combustion chamber and they are
connected together at the ends in such manner as to form a continuous zig-zag
conduit which is connected at the upper and lower end by pipes D D with the
water space of the boiler E, to which by way of example the furnace A is shewn
-connected.
The vertical spaces F F between the underside of the tubes C of one step and
the upper side of the tile B of the next step, are open, and the enclosed space G
behind the steps communicates by a passage H with the internal flue I of the boiler.
Thus assuming that the chamber A is filled with incandescent fuel and that air
entering through the passage J at top, is drawn by the chimney draught
down through the burning fuel, the resulting combustion gases and flames
will pass through the openings F into the space G and will pass thence into the
boiler flue.
Having now particularly described and ascertained the nature of this inven
ion and in what manner the same is to be performed, I declare that what I
-claim is :-
1. A down-draught furnace or producer having at one side a series of steps,
the risers or vertical spaces between which are open so that the combustion gases
in passing down through the body of fuel lying upon such steps, pass through the
said risers or openings and down into a space below which communicates with the
flue of a boiler or conduit, substantially as described.
2. In a down draught furnace or producer such as is referred to in the first claim,
constructing the steps of fire tiles resting on tubes through which water is made to
circulate.
Dated this 5th dox of Mar 1807
ABEL & IMRAY,
Agents for the Applicant.