Improvements in Reverberatory Furnaces.
Year: 1898

page_text: Date of Application, 7th Feb., 1898-Accepted, 12th Mar., 1898
COMPLETE SPECIFICATION.
Improvements in Reverberatory Furnaces.
I, JOHN QUERIN RAYNER, of Kulebaki, in the Province of Nischnij Novgorod, in
the Empire of Russia, Foundry Manager, 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:
In the construction of a reverberatory furnace the form or contour of the vault
is of great importance, and it should fulfil the following conditions.
(1) To produce a thorough mixture of the combustion gases and air, in order to
obtain the greatest advantage from the fuel.
(2) The vault should absorb as much heat as possible from the gases of combustion.
(3) The vault should distribute its absorbed heat as uniformly as possible to the
hearth below.
(4) The vault should offer the least possible resistance to the movement of the
gases.
The straight, concave, and convex vaults at present in use only fulfil these
requirements in a small degree.
In the annexed drawing, Figure 1 is a longitudinal and vertical section of a
reverberatory furnace according to my invention, such section being-taken on line xx,
Figure 2. Figure 2 is a sectional plan of Figure 1, the section being taken on
line y y, Figure 1. Figure 3 is a cross section on line z z, Figure 1.
In order to efficiently fulfil all the requirements above enumerated I provide the
vault of a reverberatory furnace with the cavities, a, a¹, on each side of the centre
line of the hearth, the portion b of the vault between the cavities being
preferably flat.
A vault constructed as above described fulfils all the above requirements, and is
equally applicable to directly heated furnaces, or gas fired furnaces, or regenerative
furnaces.
The gases entering the hearth chamber, after being mixed with air and ignited,
expand considerably, and space is allowed for such expansion by the first cavity a
in the vault, which is arranged near the gas entrance. The gases then reverberate
from the first cavity and penetrate the current of gas which is passing onward
between the flat portion 6 of the vault and the hearth.
Underneath the flat portion b of the vault the gases, which have been well
mixed but not yet sufficiently mixed, pass along at an increased speed without giving
off much of their heat and they thereupon enter the second cavity, a¹, where, owing
to their now diminished velocity, a final mixing of the gases takes place with a
complete surrender of all their heat to the hearth below.
The above described form of vault offers a larger surface contact to the heating
gases than those hitherto in use, and compels the gases to impinge against the vault
with great force, and upon the greater part thereof. Consequently, owing to its
greater absorption of heat, such a vault possesses considerable advantages over those
at present in use.
Owing to the cavities, the vault above described forces or reverberates its heat
uniformly over the hearth. I am therefore able in the case of steel melting furnaces

page_text: to distribute the heat uniformly over the whole surface of the bath, whereas in the
present furnaces the greatest heat exists at the waste gas exit portion of the furnace,
and the least heat is in or about the centre of the hearth.
In a furnace constructed according to this invention the variation of temperature
over the surface of the bath or hearth does not exceed 100° C. to 150° C., whereas in
the reverberatory furnaces now used the variation reaches 400° C. to 500° C.
In a furnace constructed according to this invention the shape of the hearth space
approximates that of the casing of a steam jet blast furnace, whereby the resistance
against the free passage of the gases is insignificant, whilst on the other hand the
internal friction of the gases is advantageously and considerably increased.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed I declare that what
I claim is:
1. A reverberatory furnace, in the vault of which are formed two cavities, a and a¹,
one of which is disposed on each side of the hearth, arranged, constructed, and
operating substantially as and for the purposes herein set forth with reference to the
annexed drawing.