Improvements in or relating to Firegrates.
Year: 1896

page_text: Date of Application, 9th June, 1896
Complete Specification Left, 16th Sept., 1896-Accepted, 17th Oct., 1896
PROVISIONAL SPECIFICATION.
Improvements in or relating to Firegrates.
1, HANS HEINRICH CHRISTIAN JÜRGENS, of Eimsbüttelerstrasse 51, Hamburg,
Germany, Engineer, do hereby declare the nature of this invention to be as
follows:-
The borizontal grates employed in marine boilers consist generally either of
separate bars or of a number of bars connected together or cast as one piece.
In both arrangements, however, there are slits of considerable width through
which a large portion of the smaller fuel falls, with the result that it is subse-
quently thrown overboard with the ashes.
With the view of obviating the evils mentioned there have been employed
polygonal grate-bars whose slits, though essentially narrow, have been arranged in
great part transversely to the surface of the grate, which renders the stoking very
difficult and, in the case of caking coal, occasions the burning and melting of the
grate-bar. Nor bave the fire-plates with round or rectangular nozzle-shaped
openings, that are sometimes used in land-boiler furnaces, been found to answer,
even with artificial draught, because they allow much too little air to pass through
and render it impossible to keep up steam with the forced working usual on.
steamships.
Now, this invention relates to a species of grate-plate that is free from all such
imperfections and is found to answer extremely well with any fuel both with
natural and with artificial draught.
Fig. 1 of the accompanying drawings is a plan and Fig. 4 an underside view of
a grate-plate according to this invention, and
Figs. 2 and 3 show sections thereof according to the lines y and vw respectively
of Figs. 1 and 4.
Figs. 5 and 7 are views similar to Figs. 1 and 4, of a modified grate-bar, and
Figs. 6 and 8 show sections thereof according to the lines 'y' and v₁ w¹ respec-
tively of Figs. 5 and 7.
Figs. 9 and 10 represent the arrangement in the fire-box of a steam-boiler of
plates such as shown in Figs. 1 to 4.
A grate-plate according to this invention consists of a plate a, usually made of
cast-iron, in which are arranged small arc-shaped, wave-shaped, or S-shaped
slits b, which widen out considerably downwards in a funnel-like manner. The
arc-shaped slits (Figs. 1 to 4 are arranged in pairs and each two of them form a
truncated hollow cone, in which by means of a connecting portion c there is secured
a solid cone e, which is placed with its point downwards. The root or upper
edges of the hollow and solid cones c and c¹ form together the slits aforesaid. The
connecting pieces c give the plate a ribbed or trussed construction, which prevents.
any warping or distortion of the plate.
The wave-shaped or S-shaped slits (Figs. 5 to 8) are each formed by arranging
in succession two arc-shaped slits b. Their conical widening produces on the
underside of the plate wave-shaped connecting pieces, which in their entirety like-
wise produce an advantageous ribbed or trussed construction.
The plates are loosely mounted in any desired number behind one another or
beside one another or behind and beside one another, on supporting-strips fastened
ip the firebox, the mounting being so effected that the slits b are longitudinal as.
regards the furnace (Figs. 9 and 10).

page_text: Grate-plates according to this invention are suitable both for lump-coal and for
slack, which may be of the finest description, the fuel being burnt in the most
complete manner. When the working is very forced-as for instance on fast
steamers so that artificial blast must be employed, the lower part of the firebox
is shut off from the outside and is connected in a known way with a blowing-
machine, a jet-apparatus, or other blast-producer.
The plates a need not be fastened on the supporting strips, for their own weight
suffices to keep them in position, even with the greatest oscillations of the ship
and the strongest blast pressure.
Dated this 9th day of June 1896.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
1, HANS HEINRICH CHRISTIAN JÜRGENS, of Eimsbüttelerstrasse 51, Hamburg,
Germany, 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 :-
The horizontal grates employed in marine boilers consist generally either of
separate bars or of a number of bars connected together or cast as one piece,
forming what are called double or treble grate bars. In both arrangements,
however, there are slits of considerable width through which a large portion of
the smaller fuel falls with the result that it is subscquently thrown overboard
with the ashes.
With the view of obviating the evils mentioned there have been employed
polygonal grate-bars whose slits, though essentially narrow, have been arranged
in great part transversely to the surface of the grate, which renders the stoking
very difficult and, in the case of caking coal occasions the burning and melting of
the grate-bar. Nor have the fire-plates with round or rectangular nozzle-shaped
openings, that are sometimes used in land-boiler furnaces, been found to answer
satisfactorily even with artificial draught, because they allow much too little air
to pass through and render it impossible to keep up steam with the forced working
usual on steamships.
Now, this invention relates to a construction of grate-plate that is free from
all such imperfections and is found to answer extremely well with any fuel both
with natural and with artificial draught.
Fig. 1 of the drawings filed with my Provisional Specification is a plan and
Fig. 4 an underside view of a grate-plate according to this invention, and
Figs. 2 and 3 show sections thereof on the lines y and vw respectively of
Figs. 1 and 4.
Figs. 5 and 8 are views, similar to Figs. 1 and 4, of a modified grate-plate and
Figs. 6 and 7 show sections thereof on the lines a¹ y' and 'w' respectively of
Figs. 6 and 7.
Figs. 9 and 10 represent the arrangement in the fire box of a steam-boiler of
plates such as shown in Figs. 1 to 4.
A grate-plate according to this invention consists of a plate a, usually made of
cast iron, in which are arranged small arc-shaped, wave-shaped, or S-shaped
slits b, which as they proceed downward, widen out considerably in a funnel-like
manner. The arc-shaped slits (Figs. 1 to 4) are arranged in pairs and each two
of them form a truncated hollow cone, in which by means of a connecting portion o
there is located a solid cone c', which is arranged with its point downwards.
The root or upper edges of the hollow and solid cones c and c¹ form together

page_text: the slits aforesaid. The connecting pieces give the plate a ribbed or trussed
construction, which prevents any warping or distortion of the plate.
The wave-shaped or S-shaped slits (Figs. 5 to 8) are each formed by arranging.
in succession two arc-shaped slits b. Their conical widening produces on the
underside of the plate wave-shaped connecting pieces, which in their entirety
likewise produce an advantageous ribbed or trussed construction.
The plates are loosely mounted in any desired number behind one another or
beside one another or behind and beside one another, on supporting-strips fastened
in the firebox, the mounting being so effected that the slits bare longitudinal as
regards the furnace (Figs. 9 and 10).
Grate-plates according to this invention are suitable both for lump-coal and for
slack, which may be of the finest description, the fuel being burnt in the most
complete manner. When the working is very forced as, for instance, on fast
steamers so that artificial blast must be employed, the lower part of the firebox is
shut off from the outside and is connected in a known way with a blowing machine,.
a jet apparatus, or other blast-producer.
The plates a need not be fastened on the supporting-strips, for their own weight
suffices to keep them in position, even with the greatest oscillations of the ship and
the strongest blast pressure.
Having now particularly described and ascertained the nature of the said inven
tion and in what manner the same is to be performed I declare that what I
claim is:-
1. A firegrate-plate with arc-shaped grate-slits arranged in pairs, each pair being
formed by a truncated hollow cone and an inverted solid cone c carried in said
hollow cone by a connecting piece c, substantially as hereinbefore described and
shown.
2. A firegrate-plate of the kind specified in the preceding claim, in which each
pair of arc-shaped grate-slits 6 are arranged in succession so as to form together
an S-shaped slit, substantially as hereinbefore described and shown.
Dated this 16th day of September 1896.
F. WISE HOWORTH,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.