Improvements in and connected with Grates for use in Boiler Furnaces and elsewhere.
Year: 1891

page_text: Date of Application, 26th May, 1891-Accepted, 27th June, 1891
DI POITICATION.
Improvements in and connected with Grates for use in Boiler
Furnaces and elsewhere.
A communication from abroad by JOSEF KUDLICZ, of Prague-Bubna, in the
Empire of Austria, Foundry Proprietor.
1, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for
Foreign Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster, and 323, High Holborn, in the
County of Middlesex, Civil 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 object of this invention is a new grate for use in boiler furnaces or else-
where, which is especially suitable for producing the perfect combustion of the fuel
employed (coal) and that, when such fuel is in the finest state of division (dust),
culm and waste products, which hitherto could not be employed for firing grates,
may also be used as fuel in connection with this improved grate.
It is here unnecessary to further go into the details which cause so many incon-
veniences and so much expense when powdery material, such as coal dust, for
instance, is employed as fuel. It will, therefore, without doubt be very advantageous
to have a grate in which there can be utilised, as fuel, coal dust and slack, and so
there be no longer any necessity for piling up the coal dust in heaps. Numerous
efforts have already been made in various ways to construct grates on which coal
dust and slack could be used as the combustible material, but all attempts have,
my correspondent believes, hitherto failed owing to the fact that the openings
of the grate, through which air should penetrate, become stopped up by the fuel,
or, owing to insufficient draught, a bright fire could not be maintained.
With this new grate, on the contrary, the complete combustion of the coal dust,
slack and waste products can be effected, and this result is attained by the
arrangement, hereinafter described, of hollow firebars through which air is forced
under a certain pressure, whereby the fuel, lying on the firebars can be completely
consumed.
On the annexed drawing, the principle is clearly shown on which this invention
rests.
Figure 1 shows a front view of a grate composed of 3 firebars K.
Figure 2 is a plan view.
Figure 3 is a view in perspective.
Figure 5 is a section of a firebar.
The firebars lie side by side, and each one is hollow, their fronts are provided
with supports R in the form of a tube and the firebars stand on a grate carrier T,
which latter is common to all the firebars.
The single hollow firebars K are now closed by a number of plates P, which, as
shown in Figure 5, are dovetailed into the firebar, the upper edge of the latter
being thickened in such a way that one plate rests close against the next, but yet
there is an interstice between any two plates sufficient to allow of play in case of
expansion of the plates

page_text: and it carries compressed' air into each hollow firebar through the connecting pipes";
the supports R form for each firebar a special air supply pipe.
On the grate composed in this manner, when it is intended to start firing, fire is
first made by igniting good fuel (lump coal or coke) and it is sustained by forcing
air into each separate firebar, which air reaches the burning material through the
perforations in the plates P. When the fire has become sufficiently bright, the
grate. is charged with dust coal or slack or any suitable combustible refuse; but
from this time the air pressure must be so regulated that the air passing through
the perforations of the plates shall have such a pressure that, on the one hand, the
fuel situated on the surface of the grate shall not be blown away, and yet, on the
other hand, the pressure of the incoming air shall be so powerful that the finely
pulverised fuel shall not rest directly on the surface of the grate but shall be in the
air at a small distance above its surface.
By the combustible floating in the air above the surface of the grate and the
particles being circulated amongst each other by the draught, the two following
results are attained :-
1. The finely divided material cannot stop up the perforations of the plates and
the air can enter unhindered.
2. The finely divided combustible, floating and circulating above the surface of
the grate, is thoroughly consumed as the heat is so great that even those parts which
burn somewhat slowly become consumed.
It is self-evident that this form of grate allows of numerous constructive alterations
and additions without thereby altering the principle which forms the basis of this
arrangement of a grate.
It is immaterial whether plain grates, movable grates or step grates are con-
structed on the above-named principle; the arrangement of the hollow firebars in
the fire box and on the grate frame allows of many modifications.
72
In order to obtain more openings in the plates for the passage of the air, it is
preferable to provide these plates P, as shown in Figure 4, on their sides with
projections which rest beneath the projections in the frame of the grate, the
projections are further provided with notches, so that the air can also pass through
the openings a so formed.
Finally, it may be further mentioned that the hollow firebars can be cleaned
during the firing operation by providing each separate firebar with a slot capable
of being shut by a damper.
If, during the firing, the damper be drawn out of the slot, the wind rushing
through the firebar blows out any refuse, ashes, etcetera, which may have
accumulated in the firebar, and on the closing of the slot, the firebar resumes its
action.
By means of the above described arrangement of grate, there is not only attained
an economical, but also a sanitary advantage.
By the use of this grate waste, mining products, which have hitherto remained
unutilisable and were uselessly burnt on the heaps and filled the whole neighbourhood
with poisonous gases, can be advantageously employed
as fuel.
Dust and slack, the cost of production of which is quite as great as of saleable
coal, have hitherto been only an encumbrance in collieries, because the removal
of this, up to the present time, valueless material, has caused expense, further,
pieces of ground for placing large heaps thereon must often be bought at con-
siderable cost, where dust and slack may be tipped in order to be burnt.
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 1 claim is :-
1. The improved arrangement of grate, mainly intended for the combustion of
dust coal, coal slack, and refuse, consisting of a number of contiguously placed
hollow firebars through which air is driven by a draught apparatus through the
plates of the grate, which latter are provided with fine perforations in such a way

page_text: that the fuel, placed on the surface of the grate, is kept floating free in the air above
the grate plates.
2. In an arrangement of fire grate such as described in Claim 1, the employ-
ment of hollow firebars, the surface of which (serving as fire plates) is provided
with fine perforations preferably widening conically towards the interior, so as to
allow the draught or compressed air coming from the draught apparatus to have
access to the fuel placed on the firebars.
3. The process of effecting the complete combustion of either coal dust or slack
on hollow firebars provided with fine perforations, in such a way that compressed
air is conducted through the hollow firebars at so strong a pressure that the material
intended to be consumed remains floating or suspended in the air above the surface
of the grate.
T 11:
WM. P. THOMPSON & Co.,
Agents for the Applicant.