IM- PROVEMENTS IN OBTAINING AND APPLYING HEAT, AND IN FURNACES EMPLOYED THEREIN, ALSO IN UTILIZING A PRODUCT RESULTING THEREFROM
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by Thomas Don at the Office of
the Commissioners of Patents, with his Petition, on the 6th May
1870.
I, THOMAS DON, of Redhill, in the County of Surrey, Millwright and
Engineer, do hereby declare the nature of the said Invention for " IM-
PROVEMENTS IN OBTAINING AND APPLYING HEAT, AND IN FURNACES EMPLOYED
THEREIN, ALSO IN UTILIZING A PRODUCT RESULTING THEREFROM," to be as
follows:-
:―
The object of the Invention is mainly to obtain and utilize gaseous
products of combustion of carbonaceous materials, such as coal, coke,
peat, wood, or like substances, carbonic oxide gas being produced, and its
combustion effected by admixture of heated air with or without steam or
liquid or gaseous hydrocarbons. The fuel being lighted at bottom and
supplied with air produces carbonic acid gas, which passing upwards
through the upper strata of incandescent fuel takes up therefrom its
equivalent of carbon, whereby the carbonic acid gas. is converted into
carbonic oxide gas, which being conducted into the furnace chamber,
apparatus, or part where the heat is to be applied, and being supplied
with regulated quantities of heated air with or without steam or hydro-

page_text: carbons, is immediately flashed into flame and gives out an intense heat
applicable to a variety of purposes, amongst which may be cited puddling
and other metallurgical operations, calcining, generating steam, con-
centrating alkaline or other solutions, &c.
The furnace is constructed with openings, regulated by dampers, slides,
or valves, to permit and control the supply of heated air, steam, or hydro-
carbons, and to give out either carbonic acid gas or carbonic oxide gas
as required. One furnace suitable for the purpose consists of an upright
fuel chamber communicating with another chamber by openings at
different levels or elevations, the gaseous products. of combustion pass
upward through the mass of hot fuel into the second or working chamber
where it is flashed into flame by admixture with the oxygen of atmospheric
air, heated by its passage through the furnace or otherwise. Steam and
hydrocarbons may also be admitted into the working chamber. The
flame is reverberated over or around a boiler, crucible, or other article or
over or around metal or other material to which the heat is to be applied.
The waste heat may be led into a third chamber fitted with vertical or
other pipes which receive air and heat it, a pipe thence conveys the heated
air to the working chamber. Baffling flues or deflectors may be used to
retain the heat and prevent its passing off too rapidly.
In kilns, ovens, and other like apparatus, carbonic acid obtained
from the fuel is passed through it and converted into carbonic oxide and
then flashed into flame by admixture with heated atmospheric air. The
gases are so applied that the greatest heat is obtained and utilized for
purposes requiring the highest temperature, and several furnaces or
apparatus may be combined or connected so that the heat after leaving
the first furnace or apparatus is carried to and used in or for a succeeding
furnace or apparatus requiring a less heat, and again from this second
to a third, and so on, each consecutive application permitting of reduced
temperatures so as to absorb and utilize the heat to the utmost. For
instance, the highest heat might be applied for reverberatory or glass
furnaces; then, the next, for calcining; the third, for heating steam
boilers or air for combustion of carbonic oxide gas; and lastly, the
remaining heat for the slow evaporation or condensing of alkaline or
metallic solutions. Thus the heat may be applied to a series of cellular
plates or troughs superimposed or placed stepwise consecutively, the heat
passing upward and horizontally first along the bottom and secondly over
the open top of the cells or troughs.. The gas thus passing may be

page_text: revivified or replenished with carbon so as to reproduce carbonic oxide.
for combustion by passing it over or through incandescent fuel so that it
may take up the equivalent of carbon which, carbonic oxide gas being
thus again supplied with heated air, is again burnt and applied as
required.
Where carbonic acid gas is given off or obtained in or from apparatus
used in any process of manufacture such as coke ovens, or lime kilns, or
other apparatus, I pass such carbonic acid gas through incandescent fuel,
or otherwise supply carbon thereto to enable it to take the equivalent of
carbon to convert it into carbonic oxide gas to be used as fuel for heating.
Carbonic acid gas so obtained after being used in various applications
may be cleansed and employed to combine with metallic or alkaline
salts or other chemical matters or to assist the action of chlorine in
bleaching.