Improvements in and connected with Water Tube Boilers, and Methods of Heating them by Liquid Fuel.
Year: 1897

page_text: Date of Application, 10th May, 1897-Accepted, 26th June, 1897
COMPLETE SPECIFICATION.
Improvements in and connected with Water Tube Boilers, and
Methods of Heating them by Liquid Fuel.
A communication from abroad by THE SOCIÉTÉ ANONYME DU GÉNÉRATEUR
DU TEMPLE, of Paris, in the Republic of France.
I, PHILIP MIDDLETON JUSTICE, of 55 and 56 Chancery Lane, London,
Fellow of the Chartered Institute of Patent Agents, 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:-
This invention relates to certain improvements in the construction of furnaces
adapted for heating boilers by means of liquid fuel. The boiler heated by liquid
fuel which is illustrated in connection with this invention belongs to the well known
class having an upper steam and water drum connected by groups of tubes with
lower water drums or collectors and heated by a reversed flame the current of hot
gases traversing the group of tubes horizontally in the direction of the depth of
the boiler.
It is differentiated from similar known types by arrangements which, without
making the boiler excessively long, permit the combustion of the gases to be as far
as possible rendered complete before they are introduced into the group of tubes.
In the annexed drawing:-
Fig. 1 is a vertical section along the axis of the boiler.
Fig. 2 represents on the left hand side, a section on the line M N Fig. 1: the
right hand side being a front elevation.
Fig. 3 is a plan of one half of the boiler on the line O. P. Q. R. Fig. 2.
In the part A is situated the atomiser the jet or jets of which are directed along
the axis of a cylindrical muffle B, of refractory material, extending to the back of
the boiler, and constituting the furnace. The air requisite for combustion enters
through the front, the hot gases passing through the opening a at the opposite end,
into the combustion chamber C. This latter is formed by the sole or hearth d the
front and back ends of the boiler, and above by an arch or vault of close water
tubes. This arch or vault is broken in front by the omission of several of the
tubes, thus admitting the gases into the cluster, this arrangement being shown in
Fig. 3.
The refractory hearth d, counteracts by radiation, the cooling influence of the
tubular arch on the gaseous current. The openings e e¹ which are provided near
the end of the muffle B allow of the introduction of supplementary supplies of air
previously heated by contact with the outside of the muffle. The air thus admitted
stirs up the gases and completes their combustion and it is then only that the latter
are introduced into the group of tubes D after traversing which they escape by
way of the chimneys E E' at the rear.
The gases between their entrance and exit from the boiler have to traverse its
length three times, namely, through the furnace, the combustion chamber and the
group of tubes respectively.
In the furnace the combustible mixture is formed or produced in the interior of
the refractory muffle at a high temperature, a condition eminently favourable to its
accomplishment.
The reversal followed by the expansion of the volume of gas during its passage
into the combustion chamber and the supplemental injections of air though the

page_text: openings e e in the norinal direction of the current in the chamber, assist in
improving the mixture of the gases whilst their combination is being completed.
The arrangement of the receiver is that usually recognised as producing the
greatest efficiency in boilers fitted with small water tubes.
Several points of detail merit special attention.
The boiler may be worked by natural or forced draught. In the former event
the openings are uncovered by a suitable valve, the air is drawn in by the
atomiser which then plays the part of an injector.
In the second case the apertures i i would be closed and the air be supplied by a
fan, the conduit 7 of which may be placed below the flooring of the boiler room.
To prevent the extinction of the jets of the atomiser by the draught, they are
protected by a bell mouthed tube m or by other suitable means..
.
Entrance to the combustion chamber and the repairing of the muffle, are effected
by way of a door r in the rear end wall of the boiler. The invention it should be
understood is not confined to the particular form in which it is illustrated.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. The arrangement and construction of the muffle furnace concentric or
practically so with a combustion chamber with which it communicates at the
opposite end to the entry of air and gas substantially as and for the purpose
described.
2. The arrangement of combustion chamber in a boiler formed around a muffle
furnace by the upper part of same an arch of tubes and the boiler ends means
being provided for introducing heated air at the point where the gases from the
muffle enter said combustion chamber substantially as and for the purpose
described.
3. The arrangement of furnace in which the muffle is employed and by which
the gases are reversed as they leave the muffle and enter the combustion chamber
and are again reversed as they enter the group of tubes substantially as and for
the purpose described.
4. The construction and arrangement of furnace for burning liquid fuel in
connection with a boiler substantially as described and illustrated.
Dated this 10th dove of M. 1907
PHILIP M. JUSTICE.