An Improved Non-conducting Composition for the Covering of Boilers, Steam Pipes, and the like.
Year: 1896

page_text: Date of Application, 4th Nov., 1896
Complete Specification Left, 15th Feb., 1897-Accepted, 22nd May, 1897
PROVISIONAL SPECIFICATION.
An Improved Non-conducting Composition for the Covering of
Boilers, Steam Pipes, and the like.
JOHN DAVID JONES, Mechanical Engineer and Proprietor Mica Works,
Howrah, British India do hereby declare the nature of this invention to be as
follows:-
This invention has for its object the manufacture of a non-conducting composition
for the covering of boilers, steam pipes &c. which, while having the desired effect
of reducing the expenditure of fuel, will, at the same time, fulfil other essential
conditions. The difficulty hitherto met with in the manufacture of such a com-
position is to get it to adhere to the surface to which it is applied, and not shrink
or crack under the intense heat of the boiler. At the same time it is necessary to
select such substances as will not seriously and injuriously affect the metal to which
it is applied.
Many of the so called non conductors of heat which have been offered to the
public owe their failure to being composed of animal and vegetable matter
rendering the metal on which they have been applied liable to injury.
These difficulties are overcome in the composition here described which consists
in combining pulverized mica with asbestos fibre (Indian asbestos by preference).
with a certain proportion of clay.
The pulverized mica must be of a certain degree of fineness, it being important
that the particles should not be too large or too small. The asbestos fibre and clay
are mixed with the pulverized mica in the proportions of 25 and 20 per cent. of the
former to 55 per cent. of the latter, more or less, when the composition is required
for high temperature, but as a non conductor of cold, the proportions vary to
25 per cent. of mica to 55 per cent. of asbestos and 20 per cent. of clay, more
or less.
The composition thus prepared only requires the addition of water to make it.
the consistency of plaster when it is ready for use.
1000
An Improved Non-conducting Composition for the Covering of
Boilers, Steam Pipes, and the like.
I, JOHN DAVID JONES, Mechanical Engineer and Proprietor of the Mica
Works, No. 70, Dobson's Road, Howrah, in India, 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 :-
1. This invention has for its object the manufacture of a non-conducting
composition for the covering of boilers, steam pipes, &c., which, while having the
desired effect of reducing the expenditure of fuel, will, at the same time fulfil other
essential conditions.
2.. For years past several attempts have been made to invent such a composition,

page_text: and much time and money have been expended in experimenting with various
substances, but with little or no success. The difficulty experienced has been to
make a composition that will adhere to the surface to which it is applied, and not
shrink or crack under the influence of the intense heat of the boiler. From this it
follows that what is wanted is a composition of an adhesive and binding character
capable of withstanding the heat it is intended to restrain. At the same time the
substances of which it is composed must be such as will not injuriously affect the
metal to which it is applied. Many of the numerous non-conductors of heat
which have from time to time been offered to the public, owe their failure in a great
measure to being composed of animal and vegetable matter, rendering the iron or
steel on which they were placed liable to injury.
3. These difficulties, which were at one time deemed insurmountable, were to a
great extent overcome by a composition which was made the subject of a patent
some three years ago. This composition, as a reference to the Specification filed
in connection with Application No. 19799-A.D. 1893 will show, was composed of
anica as its basis, (mica being a powerful non-conductor) but although pronounced
by those best able to give an opinion to be far superior to anything of its kind, the
applicant found that there was still room for improvement and so pushed on with
his experiments till he arrived at the present invention which the tests made by
him have proved beyond the shadow of a doubt to be par excellence.
4. The invention consists in adding to a definite quantity of pulverized
mica certain proportions of asbestos fibre (Indian asbestos by preference)
and clay.
Asbestos being a powerful non-conductor, as well as of a non-combustible
nature, renders it peculiarly suitable for a composition of the nature required, while
the clay used which is the common Indian clay, being of a specially plastic nature
gives the composition the necessary degree of adhesion.
5. To form the composition it is necessary to first reduce the mica to a certain
degree of fineness-it being important that the particles should not be too small
or too large. The degree of fineness will vary with the purposes for which the
composition may be required-but from 8 to 60 mesh per square inch will be found
to give what is wanted.
6. The asbestos and clay are then mixed with the mica in the proportions of
25 and 20 per cent. of the former to 55 per cent. of the latter, more or less, when
the composition is required for high teinperature, but as a. non-conductor of cold
the proportions will be 25 per cent. of mica to 55 per cent. of asbestos and
20 per cent. of clay, more or less.
7. The composition thus prepared only requires the addition of water to make it
the consistency of plaster, when it is ready for use.
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-
(1.) The improved non-conducting composition consisting of pulverized mica,
asbestos fibre and clay in the proportions substantially as herein before described
and for the purpose set forth.
(2.) In a non-conducting composition with mica as its basis, the addition of
asbestos in the proportion substantially as hereinbefore set forth and for the
purpose described.
(3.) In a non-conducting composition consisting of mica and asbestos in the
proportions set forth, the addition of clay substantially as and for the purpose
described.
In witness whereof I have hereunto set my hand this 20th day of
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