IMPROVEMENTS IN FIRE GRATES
Year: 1884

page_text: I, JAMES DONALD of Glasgow in the County of Lanark, Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN FIRE GRATES
to be as follows:-
This invention relates to improvements in fire grates whether for domestic use
or for heating boilers furnaces and other purposes and the grate as constructed in
accordance with the Invention consists of a series of trays or grates placed in
succession either directly above each other or above and behind each other according
to the direction of tho air current.
The fresh coal or fuel is placed in the lowermost tray or grate of the series
wherein it is kindled and after being thoroughly lighted the said tray with the
fuel therein is lifted up either by hand or mechanical means whilst another tray or
grate is inserted underneath for the reception of further supplies of fuel to be
kindled.
Between the level of the tray containing the fresh fuel and that of the next
higher tray or grate a hot air space is made and the gaseous products of com-
bustion from the kindling tray rise through the said space and through the partially
incandescent fuel in the tray above whereby they are consumed.
When the fuel is thoroughly incandescent on the second tray or grate of the
series the said tray is lifted up to a higher level between which and the second
level is also an air space whilst the grate or tray at the first level is lifted up to the
second level the grate or tray formerly at the third level and which now contains
only cinder and ash being brought down to the lowest level for the reception of
fresh fuel or instead of there being only three levels a greater number of levels may
be formed in the multiple grate.
Beneath the lowest level an ash pan is or may be situated, an air space being left
between it and the grate.

page_text: I, JAMES DONALD formerly of Glasgow in the County of Lanark and now of
Kalighat in the Empire of India, Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN FIRE GRATES 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 improvements in fire grates or furnaces whether for
domestic use or for heating boilers or other purposes and the grate as constructed
in accordance with the Invention consists of a series of trays or grates placed in
succession ono either directly above another or one above and behind another after
the manner of steps in a stair.
The fresh or green coal or fuel is placed in the lowermost tray or grate of the
series wherein it is kindled and after being thoroughly lighted the amid tray is
lifted up by hand or by any suitable mechanical raising device to the second level
in the series and another tray or grate is similarly inserted in the space so vacated
for the reception of further supplies of fresh or green fuel to be kindled. The
kindling may be effected by taking part of the incandescent coal from the tray
above or otherwise.
Between the level of the undermost and second trays an open or closed in spice
for the inlet and upward circulation of air is made. The air in the said space
becomes heated by radiation from the burning fuel and the gaseous products
resulting from combustion in the kindling tray rising through the said space
and through the partially incandescent fuel in the tray above are consumed
whereby fuel is economized and smoke from the improved grate is lessened or
prevented.
When the fuel is thoroughly incandescent or is burning brightly in the secondl
tray or grate of the series the said tray is lifted up to a higher level hotween which
and the second level, space for the inlet and upward circulation of air is also made.
The grate or tray at the first or kindling level is next lifted up to the second level
and the grate or tray at the highest level after its contents have been consumed
and there remains only cinder and ash is brought down to the lowest level for the
reception of fresh or green fuel to be kindled.
If desired an ash pan may be situated underneath the kindling tray or grato
space for the admission of air through the bars constituting the bottom of the
tray being left or provided.
Instead of having only three trays in series as above set forth any other desired
number may be employed in the multiple grate.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed 1 declare that what
I claim is
In a fire grate or furnace a series of removable fuel-containing trays placed in
succession either directly above each other or above and behind each other an
enclosed or open space for admission of air being provided under each tray
substantially as described.