Improvements in Grates for Boiler and other Furnaces.
Year: 1899

page_text: Date of Application, 20th Apr., 1899
Complete Specification Left, 20th Jan., 1900-Accepted, 24th Feb., 1900
Communicated from abroad by CARLO CARLONI, of 12, Via Aleravigli, Milan, in
the Kingdom of Italy, Engineer,
Improvements in Grates for Boiler and other Furnaces.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, do hereby declare the
nature of this invention to be as follows:-
The grate which forms the subject of this invention is consitituted, in the
ordinary manner, of grate bars arranged side by side. Each bar consists of two
parts, one portion (the upper) is exposed to the direct action of the fire and is
separate from the lower portion which only serves to support the weight of the
upper portion and of the combustible. The said upper portion surmounts the
lower portion without however being actually fixed thereto; it is preferably
composed of several elements which are independent one of the other and are
arranged, so to speak, astride of the bars properly so called constituting the
bearing portion of the grate.
One advantage of this arrangement is to render repairs easy of execution, as
the lower portions of the bars, which never deteriorate, as they are not exposed
to the direct action of the fire, invariably remain in position. It is therefore
only necessary to replace one of the upper parts by another, or rather a single
element of the said parts. By means of such partial substitutions, the life of a
grate becomes practically indefinite.
The lower or bearing portion of the grate is not liable to bend or to become
deformed either in a vertical or a horizontal direction as it is not subjected to
the direct action of the fire; the upper portion, which rests freely upon the
lower portion without being fixed thereto, is able to expand freely and it is
therefore possible to employ bars of great length without its being necessary to
support them by means of transverse supports. The principal cause of wear in
grates of the ordinary kind, that is to say the difference in the ratio of the ex-
pansion of the portion which is directly exposed to the action of the fire and that
which not so exposed, being eliminated, my novel grate affords a bearing sur-
face to the fuel which is absolutely plane.
In carrying the invention into practice the upper portion of the grate consists
of a series of bars provided with recesses arranged alternately upon the right
and left hand. These recesses serve for the reception of the projections arranged
upon the members of the upper portion of the grate surmounting the bars.
Each bar consists of two flat iron parts which are bolted together and recessed
as above described but of course such parts may be replaced by a single cast iron
part.
The bolts thus serve to determine the interval between two adjacent bars at the
time of assemblage. The extremities of each bar rest upon the bar carriers; the
bar support which is situated at the furnace door is provided with an aperture

page_text: for the passage of air, in such a manner as to permit of the complete utilisation
of the whole length of the grate..
The upper portion of each bar consists of a certain number of prisms which
are arranged side by side in the direction of the length of the bar without any
interval. Each of these prisms is provided with a flat bearing part for the fuel,
such bearing part projecting alternately to the right and left hand of the prisms;
pyramidal projections which are also arranged alternately to the right and left
hand, extend downwardly and engage in the recesses of the bearing portion of the
grate. Each member consequently rests astride, so to speak, upon the lower
portion of the bars.
Dated this 20th day of Ancil.1800.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, 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:-
'
2
This invention relates to grates for boiler and other furnaces and consists of
grate bars arranged side by side in the ordinary manner.
Each bar consists of two parts, the upper portion of which is exposed to the
direct action of the fire and is separated from the lower portion which only serves
to support the weight of the said upper portion and that of the fuel or com-
bustible.
The said upper portion is mounted upon the lower portion without however
being actually fixed thereto and is preferably composed of several elements which
are independent one of the other and arranged, so to speak, astride of the bars
properly so called constituting the bearing portion of the grate.
One advantage of this arrangement is that repairs may be easily executed,
as the lower portions of the bars, which do not deteriorate owing to their not
being exposed to the direct action of the fire, invariably remain in position. It
is therefore only necessary to replace the upper parts, or rather a single element
of the said parts. By means of such partial replacement, the life of the grate
as a whole is prolonged indefinitely.
The lower or bearing portion of the grate is not liable to bend or become
deformed either in a vertical or a horizontal direction as it is not subjected to
the direct action of the fire; the upper portion, which rests freely upon the
lower portion without being fixed thereto, is able to expand freely and it is
therefore possible to employ bars of great length without the necessity of pro-
viding transverse supports. The principal cause of wear in grates of the ordinary
kind, that is to say the difference in the ratio of the expansion of the portion
which is directly exposed to the action of the fire and that which is not so exposed,
being eliminated, my improved grate affords a bearing surface for the fuel which
is absolutely plane.
In the accompanying drawing I have illustrated, by way of example only, one
way in which my invention may be carried into practice.
Figure 1 is a plan view of a portion of the improved grate.

page_text: Figure 2 is an end elevation of one of the bars.
Figure 3 is a section taken upon the line A B of Figure 2 the bearing portion
being omitted and
Figure 4 is a section taken upon the same line showing the complete bars.
According to my invention the lower portion of the grate consists of a series
of bars a provided with recesses b arranged alternately upon the right and left
hand. These recesses serve for the reception of the projections arranged upon
the members of the upper portion of the grate surmounting the bars a.
As shewn in the drawing, each bar consists of two flat iron parts d, e which
are secured together by bolts f and recessed at 6 as above described, but of course
such parts may be replaced by a single cast iron bar, the said bolts serving to
determine the interval between two adjacent bars at the time of assemblage.
The extremities of each bar rest upon the bar carriers 9 and the bar carrier
which is situated at the furnace door is provided with an aperture i for the
passage of air, in such a manner as to permit of the complete utilisation of the
whole length of the grate.
The upper portion of each bar consists, as represented in the drawing, of a
number of prisms 1, arranged side by side in the direction of the length of the
bar without interval. Each of these prisms is formed with flat bearing parts m
for carrying the fuel, such bearing parts projecting alternately to the right and
left and formed with pyramidal projections n, also arranged alternately to the
right and left hand. These projections extend downwardly and engage in the
recesses 6 of the bearing portion of the grate so that each member c rests astride,
so to speak, upon the lower portion of the bars a.
Having now particularly described and ascertained the nature of my said
invention 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:-
A grate for boiler or other furnaces composed of firebars having alternate
supporting projections at both sides, characterized by the fact that such sup-
porting projections are formed with downwardly projecting parts n adapted to
alternately enter the recesses b of the lower portion c of the fire bar.
Dated this 20th day of January 1900.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.