Improved Fire Grates and Mechanical Stokers.
Year: 1893

page_text: Date of Application, 26th July, 1893
Complete Specification Left, 31st Mar., 1834-Accepted, 14th July, 1894
PROVISIONAL SPECIFICATION.
Improved Fire Grates and Mechanical Stokers.
I, WILLIAM EDWARD KOCHS, of No. 11 The Parade, Cardiff, in the County
of Glamorgan, Civil and Mechanical Engineer, do hereby declare the nature of
this invention to be as follows:-
The first part of my invention relates to the construction of the fire grate and
bars. The surface of the grate is composed of a number of short, disconnected
transverse bars, at equal distances from each other. They are placed either square
to the centre line of the grate or at an angle, and form longitudinal parallel
groups, of which each set is cast in one with, and supported by a longitudinal bar
or beam below them. Thus the grate is formed of a certain number of compound
longitudinal bars, and it will be seen, that by having transverse bars, air passages
and the influx of air will be right across the furnace and be either at right angle,
or in zigzag directions. These bars are moreover inclined or curved downwards
and in the direction of the air current, whereby the supply and flow of air to the
fuel of the grate is materially assisted. These longitudinal bars rest upon
transverse bearers in front and at the back of the grate and receive a short
intermittent motion in a longitudinal direction, which is effected by means of cams
and rollers in front of the boiler or grate. This motion may either be in a
horizontal or in a slightly upward direction, but it is slowly forward and quickly
back, the latter movement being accellerated by balance weights or springs. It
will be seen that, if the longitudinal bars lean downwards towards the boiler or
grate, the burning fuel or coal on them is, by the horizontal or upward motion,
slightly lifted and moved onwards, but by the sudden withdrawal of the bars, say,
half the distance between the centres of each pair of transverse bars, the portions
of fuel, which are resting upon the bars, are thereby shifted and placed over the
air passages or over the spaces between the bars, which takes place at intervalls
and in succession over the whole surface. There may be a separate cam to act as
motor upon each furnace bar, but half the number of these bars may be connected
by one transverse iron or steel bar in front and thus be made to move together,
and the other half may be connected by a second bar, so that, while one section
moves forward, the other moves backward.
The second part of my invention relates to the mechanical firing, or to the
manner, in which fuel is supplied to the grate, and this mechanism is by preference
arranged within the front doors themselves. In the case, when the coal or fuel is
to be spread over the burning mass, I construct the doors in the form of a
segmental box curved in the shape of a quadrant from the front downwards and
towards the grate, and within the box I arrange a horizontal or radial swivelling
box, which throws the coal over the fire. This box receives its supply in an
intermittent manner from above and, by a sudden downward motion it is thrown
forward, the back plate acting as a propeller. This sudden, radial motion is, by
preference obtained by a slowly revolving sheave above, having a dog tooth which
lifts a rod with balance weight in connection with the swivel spindle. In some
cases, according to the quality of the coal, there may not be any need of throwing
and spreading the coal over the burning mass, and it may be merely placed or
deposited on the bars immediately behind the dead plate. In such case the front
door may be constructed with two internal delivery shoots, the outer and lower one
being for nuts and the upper one for fine coal. The nuts are separated from the
fine and dust coal by means of a small screening grate, which is arranged in the
upper or fixed portion of the apparatus above the doors. Thus, while the nuts
are sliding over the screen and over the front or lower delivery shoot on to the

page_text: surface of the grate bars, the fine coal is being spread over the top of them, which
has the advantage, that the passing of the air into the burning fuel is facilitated
and the shifting of the nuts from bar over the space and from space to bar is
assisted.
Witness my hand this Twenty-fifth day of July One thousand eight hundred 5
COMPLETE SPECIFICATION.
Improved Fire Grates and Mechanical Stokers.
I, WILLIAM EDWARD KOCHS, of No. 11 The Parade, Cardiff, in the County
of Glamorgan, Civil and Mechanical 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 first part of my invention relates to the construction of the fire grate and
bars. The surface of the grate is composed of a number of short, disconnected
transverse bars at equal distances from each other. They are placed either square
to the centre line of the grate or at an angle, and form longitudinal parallel
groups, of which each set is cast in one with and supported by a longitudinal bar
or beam below them. Thus the grate is formed of a certain number of compound
longitudinal bars and it will be seen that by having transverse bars, air passages
for the influx of the air will be right across the furnace either at right angles or
in zigzag directions. These bars are moreover curved or inclined downwards in
the direction of the air current, whereby the supply and flow of air to the fuel on
the grate is materially assisted. These longitudinal bars rest upon transverse
bearers in front and at the back of the grate and receive a short intermittent
motion in a longitudinal direction, which is effected by means of cams and rollers
in front of the boiler or grate. This motion may either be in a horizontal or
in a slightly upward direction, but it is slowly forward and quickly back, the
latter movement being accellerated by balance weights and levers or by springs.
It will be seen that if the longitudinal bars incline downwards or towards the boiler
or grate, the burning fuel or coal is, by the horizontal or upward motion lifted and
moved onwards, but by a sudden withdrawal of the bars, say half the distance
between the centres of each pair of transverse bars, the portions of fuel, which
are resting upon the bars are thereby shifted and placed over the air passages, or
over the spaces between the bars, which takes place at intervals and in succession
over the whole surface. There may be a separate cam to act as motor upon each
furnace bar, but half the number of these bars may be connected by one transvrse
iron or steel bar in front and thus be made to move together, and the other half
may be connected by a second bar, so that while one section moves forward, the
other moves backward.
The second part of my invention relates to the mechanical firing, or to the
manner, in which fuel is supplied to the grates and this mechanism is, by preference
arranged within the front doors themselves. In the case, when the coal or fuel is to
be spread over the burning mass, I construct in the doors a horizontal, segmental
or circular box and within it I arrange a radial swivelling apparatus which is to
act as a shovel and back plate, the shovel is to receive the small coal and the back
plate is to propel it on a sudden radial motion over the grate. The swivelling box
or shovel receives the coal in an intermittent manner from above, and the sudden
radial motion is, by preference obtained by a slowly revolving sheave above, fixed
on a shaft driven by steam power, having a dog tooth, which lifts a rod with
balance weight in connection with the swivel spindle. In some cases, according to

page_text: the quality of the coal, there may not be any need of throwing and spreading the
coal over the burning mass, and it may be merely placed or deposited on the bars.
immediately after the dead plate. In such case the front door may be constructed
with two internal delivery shoots, the outer and lower one for nuts and the upper
one for fine coal. The nuts are to be separated from the fine or dust coal by
means of a small screening grate, which is arranged in the upper or fixed portion
of the apparatus above the doors. Thus, while the nuts are sliding over the
screen and over the front or the lower delivery shoot on to the surface of the grate.
bars, the fine coal is being spread over the top of them, which has the advantage,
that the passing of the air into the burning fuel is facilitated as well as the shifting
of the nuts from the bar over the spaces and from the spaces to the middle of
the bars.
With reference to the accompanying drawings, Figure 1 represents a longitudinal
section of fire grate with ordinary firing door, Fig. 4 shews the plan, Fig. 5 the
transverse section through the grate and bars and Fig. 6 detail of transverse bars.
A, A¹
are the longitudinal fire bars of which every other one, i.e. the first,
third fifth
and second, fourth
form each one section, connected
together by the bars B and B¹ and are acted upon and moved longitudinally by
cams C and C and rollers D.. The latter revolve on the upper ends of levers E
which grip the ends of the connecting bars B and B' and while the cams push the
rollers and bars slowly onwards, the levers E and balance weights F move them,
on being released by the cams, quickly back. The grate surface is composed of
short disconnected grate blocks G, G, G. Figs. 1, 2, 3 and 4 shown in larger
scale Fig. 6, and these are placed either at right angles or in oblique directions, as
shewn on plan Fig. 4. Fig. 6 shews a piece of coal on the middle of a bar and if
the motion of the latter be half the distance from centre of one bar to the next or
from one space to the next x,-z, then the coal will be moved or lifted forward and
placed over the spaces and exposed to the air current which passes in the direction
of the arrows. By this manipulation the bar surface receives, so to say, a
lubrication by a thin sheet of cold air and is prevented from burning. Fig. 2
shews the apparatus for shovelling and propelling the coal on to the grate. The
fuel descends into the shovel K from I and is by a sudden horizontal, radial
motion, which is communicated by an apparatus as illustrated in Fig. 7, thrown
over the grate surface. A lifting, or dog tooth on sheave M lifts the block N with
spindle, balance weight O, and tooth rack P and thereby turns the wheel Q and
shovel into the position to receive the charge of coal. When the block is lifted to
the highest point and liberated, the rod descends suddenly and while the tooth rack
turns the wheel in the direction of the arrow, the coal is discharged and propelled.
Fig. 3 shows the mode of screening, or separating the nuts from the fine coal.
A screen R in a box above the door causes the nuts to fall on the shoot T and the
fine coal on S, spreading it over the nuts. The grate is self cleansing and the bars
are prevented from burning or melting. There is perfect combustion and a
complete burning of smoke.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that, what I
claim is:
1. Constructing the bars substantially as described above, that is, forming the
grate surface of a number of disconnected blocks or of short transverse or oblique
bars.
2. Creating continuous air passages right across the grate surface and bringing
air in contact with every portion of the fuel by moving the bars half the distance
from centre to centre of one bar and another and shifting the fuel from bars to, or
over the spaces.
3. Causing an air lubrication on the grate surface by a sudden withdrawal of
the bars.
4. Connecting half the number of bars by one transverse bar and the other half

page_text: by a second bar and moving each set by a pair of cams and drawing them back by
levers and balance weights or by springs.
5. The construction of a mechanical shovel and propelling plate and the
way they are acted upon and revolved, substantially in the manner as above
described.
6. The plan of screening small coal or of separating the nuts from the fine coal
and of placing the nuts direct on the grate bars and spreading the fine coal
over them.
Dated this 29th day of March 1894.
WILLIAM EDWARD KOCHS,
Civil and Mechanical Engineer,
No. 11, The Parade, Cardiff, in the County of Glamorgan