Improvements in Kilns and Furnaces and in Steam Boilers used in connection therewith.
Year: 1893

page_text: Date of Application, 21st Feb., 1893-Accepted, 8th Apr., 1893
COMPLETE SPECIFICATION.
Improvements in Kilns and Furnaces and in Steam Boilers used in
connection therewith.
I, ALBRECHT STEIN of Wetzlar in the Kingdom of Prussia, Empire of
Germany, Manufacturer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to he particularly described and
ascertained in and by the following statement:-
My invention consists in the combination, with a kiln or furnace constructed of
sheet-iron, steel or metal plates and without any inside lining of fire-bricks or other
refractory material, of a steam-boiler surrounding said kiln or furnace, for the
purposes; first, to cool the metal of the kiln or furnace and thereby to prevent the
metal from being destroyed by the heat; and, second, to develop steam in
the boiler, generated by the heat of the kiln or furnace, which heat, otherwise,
would be lost by radiation.
My invention is particularly destined for application to kilns for the calcination
of lime, cernent and other similar material, but it may equally and with good
advantage be applied to melting furnaces.
Kilns and furnaces, constructed of iron or steel, are known; to prevent the metal
from being rapidly destroyed by the great heat, the metal shaft of the kiln or
furnace used to be lined with fire-brick or the like, which lining, however, is very
liable to destruction, too, and when its inside surface becomes worn out, uneven and
bulged, the charge of lime or cement or other material to be calcined is prevented
from sinking down within the shaft smoothly and in regular course, but it requires
to be stirred by iron rods or implements, and, thereby, the operation of calcination
is not only interrupted and retarded but the material under treatment is not
obtained of such a uniform and good quality as if the operation proceeds without
any interruption and stirring.
In the accompanying drawings, I have illustrated my invention by representing
a vertical section of a kiln A of sheet iron plates, surrounded by a steam-boiler B,
the fire-place and flue of which are formed by the said kiln A. The boiler B is
provided with the usual fittings, water-gauge, safety-valve and the like; the feed-
water is supplied through a pipe b at or near the lower end of the boiler and the
steam is led off through a pipe 61 at or near the upper end, which pipe may lead
into a steam-collector, where the steam is superheated in the usual manner.
The greatest heat in the kiln or furnace A is usually at or about the middle part
of its height; the feed water, therefore, entering at the lower end of the boiler,
will not at once come into contact with that portion of the flue where the greatest
heat exists, but it will become gradually heated while rising within the boiler, and,
when it comes in contact with the most heated portion, the steam will be rapidly
developed.
The metal kiln or furnace A, being cooled all around by the water of the boiler,
requires no lining of refractory material and is, nevertheless, prevented from being
destroyed by the heat; the shaft of the kiln, being cylindrical or slightly tapering,
allows the charge to sink gradually down without any stirring and interruption, in
consequence of which the product obtained is of a good, perfectly uniform quality,
and the quantity obtained is also considerably larger than that produced with kilns
of usual construction lined with fire-brick.
I am aware that iron furnaces are known, which are constructed without an inside
lining of refractory material. To prevent the metal from suffering by the heat, the
outside of the chamber is cooled by water applied to the outside by circulation or
otherwise; but the heat absorbed by the cooling water is entirely lost in such
furnaces, while, in the combination which forms the object of the present invention,

page_text: the heat absorbed by the water is utilised through the generation of steam, which
may be employed, as desired, for working engines, driving machinery and apparatus
of any kind, or for heating or drying purposes.
I prefer to construct the shaft of the kiln or furnace of sheet metal rings which
may be easily taken asunder and changed if, in the course of use, they become worn,
but the mode of jointing the plates of the shaft A, as also those of the boiler B,
may be varied, and my invention is not limited to the special mode of jointing the
sheet-metal plates of the shaft A and boiler B.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :
The combination, with the shaft of a kiln or furnace constructed of metal plates,
of a steam-boiler surrounding said shaft in such a manner that the water of the
boiler serves to cool the metal of the shaft and the heat of the furnace serves to
generate steam in the boiler, substantially as set forth.
Dated this 20th day of February 1902
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.