Improvements in Furnace Fire Grates for Boilers.
Year: 1897

page_text: Date of Application, 21st July, 1897-Accepted, 7th May, 1898
COMPLETE SPECIFICATION.
Improvements in Furnace Fire Grates for Boilers.
I, REGINALD HADDAN, of the Firm of Herbert Haddan & Co., of 18, Buckingham
Street, Strand, London, Patent Agent, do hereby declare the nature of this
invention a communication to me from abroad by Messrs. Marc and Scherding,
of 258, Rue des Pyrenees, Paris, Engineers, 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 an improved grate for boilers.
This new grate is constructed on the principle that one cannot derive from a
combustible holder alone which constitutes the grate hitherto known, all the
functions, which are required to form a combustion which can be varied according
to the nature of the combustible to be used and the service it is to be put to.
All that can be expected from this ordinary grate is the support of the com-
bustible and the other functions for varying the combustion must be fulfilled by
means of supplementary contrivances.
This improved grate fulfills entirely these functions, for it produces the following
triple effects: 1, support of the combustible and this under the best known
conditions; 2, regulation of the introduction of air; 3, the division and dis-
tribution of the air in a rational manner under the whole layer of combustible in
ignition.
In the annexed drawing-Fig. 1 is a side view of our grate in longitudinal
section. Fig. 2 is a plan view, the bars supporting the combustible being removed.
Fig. 3 is a view in cross section.
As can be seen from these drawings our grate is composed of three distinct
elements. The support A, the air heater B and the regulator or distributor C.
The support A is intended for receiving the combustible and is formed of bars a
of any form, suitable for the nature of the combustible and for the type of the
boiler or generator used.
The air heater B is formed of, bars 6 of preferably triangular section, plain or
hollow, composed of iron and crossed over one another their apices being turned
towards the combustible holder and their bases turned to the side of the air
admission. This arrangement has two purposes. The ash falling through the
bars from the combustible holder encounter an apex and cannot accumulate on
the bars. Also this formation of bars presents to the air which is carried toward
the combustible a more restricted air passage than that which exists between the
bars of the support, and there results first a retarding action which allows the air to
get hot, then a kind of expansion which obviates sudden draughts striking on
particular points of the layer in ignition, which sudden draughts render any
rational and economical combustion absolutely impossible.
We place the air heater B under the support A and generally parallel to it, but
it is evident that we can also place it lower and at such an inclination, as we
think necessary in order to secure a better operation. It is the same for the
regulator C which is formed of blades c of any convenient form, placed preferably
horizontally under the heater and transversely these blades which
we call

page_text: ventilators are mounted by pins 1 on the framing 2 of the grate which framing is
of a sufficient height, in order that the air can only pass between the blades c
and not at the sides, 3 are forks fixed on the blades, preferably in the middle and
connecting them to the bar 4 by means of which the said blades can be made to
oscillate forwards or backwards in order to open or to close the passage for
the air.
It is understood that, instead of operating all the blades by only one bar, we can
divide them into groups and operate each group by means of a different bar.
We can also place them longitudinally instead of transversely and varying
consequently the operating devices.
We can also connect the operating devices of the blades with any machine in order
to obtain a continuous oscillation of the said blades.
We claim also to combine together only the support A and the air heater B, on
the support A and the regulator C, without departing from the spirit of this
invention.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed I declare that what I
claim is-
In grates for generators etc.
1. The combination of a support A formed by bars a arranged in any convenient
manner with an air heater B formed of bars 6 crossing one another and presenting
for the air passage a section smaller than that formed by the intervals of the bars a
of the support A.
C
2. The combination of a support A formed of bars a arranged in any convenient
manner with an air regulator C formed by movable blades e mounted on gudgeons 1
on the framing 2 of the grate and capable of sinking and rising by the operation of
a bar 4 with which they are connected by cramps 3 or any other analogous
arrangement for opening or closing the passage of the air to the combustible.
3. The combination of a support A formed by bars a arranged in any convenient
manner, with an air heater B formed by bars b crossing one another and presenting
to the passage of the air a smaller section than that formed by the intervals of the
support A and an air regulator C, formed by movable blades c mounted on
gudgeons 1 on the framing 2 of the grate and capable of sinking or rising by
operation of a bar 4, with which they are connected by means of cramps 3 or in
any other analogous manner, the whole as hereinbefore described and shown in the
annexed drawing and for the purpose stated.
Dated this 21st day of July 1897.