Improvements in or relating to the Manufacture of Fire and Acid Proof Bricks, Slabs, and other Earthenware Articles or Structures.
Year: 1898

page_text: Date of Application, 18th Nov., 1898-Accepted, 28th Oct., 1899
Improvements in or relating to the Manufacture of Fire and Acid
Proof Bricks, Slabs, and other Earthenware Articles or Structures.
I, ERNST WILHELM ENGELS, of Nikolausstrasse 14, Essen a/d Ruhr, in the
German Empire, 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:---
'
This invention relates to improvements in or relating to fire and acid proof
materials. The means at present in use for manufacturing fire-proof material
or rendering substances fire and acid proof consists in forming or applying a
varnish or enamel on bricks, plates, or other material to be rendered fire-proof.
My invention relates to a new process of rendering material fireproof and con-
sists in covering or forming on, with the aid of electricity, the surfaces of such
material with carbides of any kind, such for instance as carborundum and
thus producing a fire and acid proof surface.
"
The fire-proof or acid-proof material may be produced by covering the surface
of such material by electrical means with carborundum or other carbide melted
or fused on to it; the carbide being employed when in its finished state or being
produced during the fusing, by using the necessary ingredients.
In carrying out my invention according to an approved method the silica,
dinas, chamotte (a mixture of fireclay & fragments of burnt pottery) or carbon
blocks or like material, which it is intended to render fire resisting and acid proof
are strewed over with a mixture of siliciumdioxide and carbon, the first in the
form of say quartzite or sand, the latter in the form of coal, coke, charcoal or
graphite. To prevent the cracking, or breaking of the blocks in consequence of
the great heat to which they are subject under the action of the electric
arc, they are previously heated, then covered by the mixture which is
fused into them by means of the electric arc. By the fusion under
such circumstances generally a carbide in this case, a combination of car-
bon and silicium is produced, sometimes called carborundum, which has
great fire resisting and acid-proof qualities and which intimately adheres
to and forms part of the block. The invention may be applied to the
walls of already built furnaces or foundries, or parts of them, which are exposed
to exceedingly high temperatures. In this case the mixture of silicium-dioxide
and carbon is made up with tar or other binding substance, and applied as a
coating to the walls and then fused by means of the electric arc. The expansion
co-efficients of both the plates or blocks and the carbide being nearly the same,
no rents or cracks are produced on the fire resisting coating in consequence of
great change of temperature, in consequence of which their adoption is of the
greatest importance especially in steel furnaces, owing to the great reduction
in temperature after each operation or at the conclusion of work. Independently
of its special quality as a fire resisting material, the smooth surface of the material
is adapted to retard the heat penetrating readily into the interior of the blocks,
much more so than is the case with the fire resisting materials used at present,
into which the heat, owing to the more or less rough surface, enters very readily.

page_text: The present invention, will, moreover, be greatly conducive to the preservation
of basic furnaces, inasmuch as, hitherto, they have been exclusively built of
acid material or stones. When such a furnace is heated, the silica stones begin
to run," the acid mass. falling in drops on the fire bridges, and back and front
walls, eating away large holes wherever it chances to fall. It often happens
that the basic slag is rendered acid by the runnings of the silica stones, especially
from the arches, the slag becomes acid and consequently thin, and the steel
disturbed; thus necessitating a prolongation of the process, the addition of more
lime for the purpose of making the slag basic, before it is possible to tap the
charge. By using blocks produced according to my invention, such "running
is impossible, thus rendering the invention of very great value and importance.
Moreover in the case of regenerative furnaces, the use of blocks produced accord-
ing to my invention will ensure the flues and passages being free of slag, which is
of great importance inasmuch as the life of a furnace of this description depends
greatly upon this.
"
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. Applying a coating or surface of carborundum or other carbide to bricks
plates and other material to be rendered fire and acid proof.
2. Forming a coating of carborundum or other carbide on bricks, plates or
similar materials by electrical means.
3. A fire and acid proof material substantially as described.
BOULT & WADE,
Agents for the Applicant.