Improvements in and relating to Mantles and the like for Incandescent Gas Burners.
Year: 1897

page_text: Date of Application, 15th June, 1897-Accepted, 17th July, 1897
COMPLETE SPECIFICATION..
Improvements in and relating to Mantles and the like for
Incandescent Gas Burners.
I, JOHANNES CARL JULIUS STEINBACH of 411 Brandsensestrasse, Hamburg,
Merchant, do hereby declare the nature of this invention and in what manner
the same is to le performed to be particularly described and ascertained in and by
the following statement:-
Mantles or the like for incandescent burners, containing a thorium and a
Cerium oxide, give when heated in a Bunsen flame, and when about 99 parts of
thorium oxide and one part of cerium oxide are used, the maximum illuminating
power which can be obtained with these two materials, and a white light. With
an increasing percentage of cerium oxide the colour of the light turns to yellow
and the illuminating power decreases very considerably. Thus a mantle or the
like composed of about 96 parts of thorium oxide and four parts of cerium oxide
gives a light of a yellow colour and of a very considerably smaller illuminating
power.
Now on adding about 25 per cent. of silicic acid to a mixture of 96 parts of thorium
oxide and four parts of cerium oxide, the colour of the light emitted from a mantle
or the like made of said mixture is no longer a pronounced yellow, but is pure
white, and its flluminating power is even greater than that of a mantle or the like
composed of 99 parts of thorium oxide and one part of cerium oxide.
According to the proportions of the mixture employed of thorium oxide and
cerium oxide, and according to the desired colour of the light, the addition of
silicic acid may be made greater or smaller. Even the use of small quantities of
silicic acid has a favourable effect upon the mantles or the like.
In general it may be stated that as a rule with the presence of silicic acid, the
percentage of cerium oxide in proportion to the thorium oxide, in order to obtain
the most favourable illuminating effect, must not be appreciably greater than is the
case with mantles or the like which are composed solely of thorium oxide and
cerium oxide.
The illuminating power of mantles and the like containing silicic acid,
generally increases considerably in intensity for about and during the first ten
hours of burning, and then remains constant during the whole time of burning
because the several components have imparted to them by the silicic acid a consider-
ably increased degree of refractoriness or resistance to the action of fire which
renders a volatilisation of the same impossible, whilst mantles or the like which
contain silicic acid have also a much greater resistance or strength and are there-
fore better able to withstand external influences. The considerable influence
exerted by silicic acid is also shown by the fact that a mantle of thorium oxide
and cerium oxide weighs about six hundred milligrammes whilst the same body
of exactly the same dimensions, but containing about 20 per cent. of silicic acid,
has only a weight of about 350 milligrammes. A. pure solution of silicic acid is
produced from the dilute solution of alkaline silicates by the addition of acid,
and the separation of the crystalloids and of the acid in excess by means of
dialysis. The solution of silicic acid remaining in the dialysator is

page_text: added to the solution of thorium and cerium, and the fabrics are
impregnated in the usual manner therewith. The fabrics may also be first
impregnated with silicate of potassium or of soda " water glass" from which
silicic acid may be precipitated in the fabric by means of suitable precipitating
agents, and the soda salts or potash salts thus formed can be removed by washing.
Or the fabrics may be impregnated with hydro-silico-fluoric acid and after drying
may be treated with ammonia, whereby silicic acid is separated and the fluor-
ammonium is dissolved. Or the fabric may be impregnated with chloride of
silicon and the silicic acid be precipitated in the fabric in an insoluble form by
means of water. The silicic acid fabrics formed in this manner would then be
further treated with solutions of thorium oxide and cerium oxide.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
(1) A mantle or the like for incandescent burners, composed of thorium and
cerium oxide characterised by a percentage of silicic acid for the purpose of im-
proving the duration of illumination, the emission of light, the fireproof quality,
and the strength of resistance of the mantle, as set forth.
(2) A process for the manufacture of the mantle or the like specified in Claim 1,
by burning out a fabric impregnated with a solution of thorium and cerium,
characterised by the impregnation of the fabric with a solution of silicic acid, as
set forth.
(3) A modification of the process specified in Claim 2, characterised by the fact
that the silicic acid is produced in the fabric itself by precipitation from solutions
containing silicon (for example from a solution of water glass by means of acids;
from hydro-fluor-silicic acid by means of ammonia: and from chloride of silica
by means of water and the like) as set forth.
(4) The improvements in mantles and the like for incandescent burners,
substantially as herein described.
ROBERT E. PHILLIPS, Assoc. M. Inst. C.E., M.I. Mech. E.,
Consulting Engineer & Patent Agent,
70, Chancery Lane, London, W.C., Associate Agent.