A NEW OR IMPROVED PROCESS FOR MANUFACTURING TILES, BRICKS, AND OTHER ARTICLES OF THE LIKE KIND, TO BE USED IN BUILDING OR FOR ORNAMENT
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Edmund Edwards at the Office of
the Commissioners of Patents on the 20th February 1883. A communi-
cation to him from abroad by Paul Alexandre Sazerae, of Peruzet, in the
Republic of France
EDMUND EDWARDS, of the firm of Edwards and Co:-, Patent Agents and
Engineers, of 40, Southampton Buildings, Chancery Lane, in the County of
Middlesex "A NEW OR IMPROVED PROCESS FOR MANUFACTURING TILES, BRICKS,
AND OTHER ARTICLES OF THE LIKE KIND, TO BE USED IN BUILDING OR FOR
ORNAMENT [a communication to him from abroad by Paul Alexandre Sazerae,
of Peruzet, in the Republic of France]
"
This invention has for its object a novel method of and process for manufacturing
tiles, bricks, or other articles of the like kind, of burned clay or suitable earth,
coloured black or slate grey throughout their substance by means of finely divided
carbon, and the preservation of such material by the introduction into its pores,
whilst it is at a high temperature, of such finely divided carbon.
The articles manufactured in the usual way of such materials, and dried
sufficiently previous to being burned in a kiln, are submitted to heat in an ordinary
reverberatory furnace slightly modified for the purpose of this invention in the
following manner.
Such ordinary furnace is usually provided with one or more lateral fire-places by
means of which the articles are burned or baked.
The hot gases after rising to the top of the furnace are made to descend by one
or more openings in the floor or flues which communicate with a chimney.
The modification in such furnace for the purpose of the present invention,
consists in arranging a sufficient number of regulators or dampers, one being fixed
in the flue which connects the furnace with the chimney, so that when required
the former can be completely shut off from the latter; and others being arranged
at the mouths of the fireplaces, so that the openings can be hermetically closed.
When the improved process is to be applied to unburnt articles, they are placed
in a furnace arranged as described, where they are submitted to the necessary
temperature, by the combustion of wood, coke, coal, turf, or other suitable fuel,
the time required for burning the articles varying according to the nature of the
fuel used.

page_text: When the burning is completed, instead of allowing the articles to cool in the
usual way, the grates of the fireplaces are removed and their place is filled either
with logs of wood of convenient diameter, upon which the bark is left, or with
vessels filled with coal tar, heavy oils, vegetable tar, wood, or other substances
which are rapidly ignited by the heat of the walls of the fireplaces, and first the
flue from the furnace to the chimney is closed as quickly as possible by shutting
its regulator or damper and stopping all the joints with a refractory cement
prepared beforehand, and then the openings of the fireplaces by means of their
dampers, their joints also being stopped with cement.
An imperfect combustion in a closed chamber is thus produced. The carbonic
acid, carbonic oxide, and carburetted hydrogens, which are disengaged at once at
the commencement of the operation before the furnace was sealed up as described,
are imprisoned, combustion becomes incomplete and a thick smoke is produced
which coming in contact with the articles already at a red heat, penetrates by
degrees into their pores and combines with the material of which they are made,
the mixture being so intimate..(as examination proves) as to constitute a true
combination. The result described requires for completion in the closed furnace
from 72 to 96 hours, and if time can be spared it is preferable not to withdraw the
articles from the furnace until they have cooled to about 60° centigrade.
Where the improved process is to be applied to articles already burned, if any
kind of furnace is available in which they can be heated more rapidly or at less
-cost than in a reverberatory furnace, they may be placed in it (the modifications.
already described having been first made) and brought to a dark red heat, and the
process is then continued as already described, that is to say by causing an
imperfect combustion in a closed chamber, of wood, coal tar, heavy oils, or vege-
table tar.
The red hot articles absorb the finely divided carbon of the smoke and become
slate grey.
By the novel process described the external colour of the articles treated is
exactly that of slate; the colour of their interior, when the process is successfully
carried out is that of slate schists; and they are as impermeable as the best slates.
The finely divided carbon filling all the pores of the material, renders the surface
of the articles extremely smooth, and the deposit of organic matter upon them is
in consequence rendered difficult, mildew or other fungoid vegetation not being
able to develope itself.
Articles produced by the novel process described have the appearance of slate
though cheaper, and are very solid, impervious, and durable, as compared with
such articles as ordinarily manufactured.