Improvements in Non-conducting Coverings for Pipes, Boilers, and other purposes.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Non-conducting Coverings for Pipes, Boilers, and
other purposes.
I, HENRY COLBECK MICHELL, of 9, Jordan Street, in the City of Toronto, in
the County of York, in the Province of Ontario, Canada, Manufacturer, do
hereby declare the nature of this invention to be as follows:-
My invention relates to non-conducting coverings for pipes and boilers etc.
and the object of the invention is to devise a simple cheap and easily made non-
conducting covering for heated (or cold) surfaces especially pipes and boilers
which will have very great non-conducting property; and it consists of a covering
comprising mica or other suitable material or composition held by a suitable
binding medium to form a solid outer skin or shell the interior space of which
is filled with or contains a mass of mica either in the form of flakes or particles
forming multitudinous air spaces or cells or a porous mass as hereinafter more
particularly explained.
For producing coverings of curved form according to my present invention I
may proceed as follows:-
--
Fig. 1 is a cross section of my non-conducting covering applied to a pipe.
Fig. 2 is a longitudinal section through the line -y Fig. 1.
Fig. 3 is a perspective view of portion of a mould by which my pipe covering
may be formed.
Fig. 4 is a detail of portion of the mould for forming the inner portion of the
pipe covering showing such mould in reverse position.
Fig. 5 is a cross section showing an alternative form of making my non-
conducting covering.
Fig. 6 is a longitudinal section through the linery Fig. 5.
In the drawings like letters of reference indicate corresponding parts in each
figure.
I first sprinkle advantageously upon a sheet of paper or any suitable backing
of the desired length or width to completely cover the interior of the mould Ä
mica in flakes or particles. I next sprinkle any suitable binding medium advan-
tageously silicate of soda in solution upon the mica previously superimposed
upon the sheet so that the mass now becomes oppy or spongy the silicate of
soda in solution being very sticky becoming mixed with th mica and the latter
becoming impregnated with such binding medium.
If desired the above steps may be repeated several times to attain the desired
thickness. This spongy or soppy layer I lift into the mould and place it in con-
centric form as indicated at B. I then fill in flake mica or mica in lamine
form concentrically as indicated in Fig. 3 thereby forming multitudinous
air spaces c.
I may advantageously use larger flakes at the outside decreasing
in size towards the centre.

page_text: Upon the inside of the top D of the mould (either with or without laying a
sheet of paper E thereon) I place silicate of soda in solution mixed with mica to
form a layer F as hereinbefore described as to the layer C such layer F also
forming a soppy or spongy mass.
Upon the bottom of the mould previously filled as herein before described I
turn the top as indicated in Fig. 3. It will thus be seen that the concentrically
formed layer already in the mould will become incorporated to some degree with
the concentrically arranged layers C hereinbefore described similar to what the
concentrically arranged layers C will become incorporated with the layers B the
silicate permeating in both cases into the mica particles flakes or laminae C.
This permeation or partial permeation of the concentric layers of mica C is
effected in a peculiar manner as the silicate of soda in solution in the outer
layers insinuates itself from said outer layers irregularly into the interior
strata C.
The mould after the above steps are taken is put into a furnace which pro-
duces a state of ebullition in the silicate of soda and causes the latter to permeate
the layers in an irregular manner marked see Figs. 1 and 5 and bind the mass
together these mound-like projections b extending into the central layers C
and effectually key the mica in position and prevent lateral or longitudinal dis-
placement.
Although I describe silicate of soda as the binding and locking medium for
the mica it will be understood that any other suitable non-combustible binding
medium may be employed and the drying thereof effected in any suitable
manner.
In Figs. 3 and 4 I show the manner of making one-half of the pipe covering
and the other half shown in Fig. 1 would be made in the same manner. When
the moulds are placed together and put in the furnace or otherwise dried the
skin formed by the silicate would be continuous alike around the concentric as
well as the radial portions thereby completely encircling the mica in the interior.
In a covering so manufactured as I describe it may be sawn off into any
desired lengths and when placed together in halves may be covered on the
outside in the usual manner by canvas or other suitable material.
In Figs. 5 and 6 I show an alternative form in which I use a mass Ct of
particles of mica not necessarily concentric in fact mixed in any way.
The outer and inner lays B and F of the mica permeated with the silicate in
this case also form a series of mound-like irregular projections 6 and f projecting
inwardly into the mass of particles and effectually serving to key the mica both
from longitudinal and lateral displacement. The cover is formed in this case
in the mould in the manner hereinbefore described with the exception that
there are no concentric layers.
This keying of the mica in position allows of multitudinous air spaces. In
Fig. 1 these multitudinous air spaces are formed between the concentrically
arranged flakes as indicated and being irregular and arranged concentrically
they act like so many non-conducting deflecting plates which thereby assists
in producing the extraordinary heat non-conductivity of this covering.
In Fig. 5 in which the alternative form is shown and which of course is a
cheaper construction the dead air spaces are formed in the heterogeneously
mixed mass of particles C. It will thus be seen that I utilize to a maximum
extent the two greatest non-conducting agencies riz.: dead air spaces and mica.
Instead of proceeding in the manner and by the means hereinbefore set forth
and illustrated -I may produce coverings of other than curved form for instance
I may make flat or irregularly shaped non-conducting coverings of a mass of
mica flakes, laminæ or particles or combinations thereof and a suitable binding
medium permeating the outer portion of such covering and forming a more or
less solid skin or shell thereto while the inner or interior portion of the mass
is very porous .e. has multitudinous interstices or non-communicating air spaces

page_text: or cells therein and same may be moulded as aforesaid or formed in any other
suitable manner.
I do not confine myself to making the aforesaid solid skin or shell (or all of
same) from mica only-as if desired I may use any other suitable material or
composition for forming said skin or shell and fill the interior of the latter with
mica either in the form of flakes or particles or both so as to thereby obtain the
object of my present invention.
Improvements in Non-conducting Coverings for Pipes, Boilers, and
other purposes.
I, HENRY COLBECK MICHELL, of 9, Jordan Street, in the City of Toronto, in
the County of York, in the Province of Ontario, Canada, Manufacturer, 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:-
My invention relates to non-conducting coverings for pipes and boilers etc.
and the object of the invention is to devise a simple cheap and easily made non-
conducting covering for heated (or cold) surfaces especially pipes and boilers
which will have very great non-conducting property; and it consists of a covering
comprising mica or other suitable material or composition held by a suitable
binding medium to form a solid outer skin or shell the interior space of which
is filled with or contains a mass of mica either in the form of flakes or particles
forming multitudinous air spaces or cells or a porous mass as hereinafter more
particularly explained.
For producing coverings of curved form according to my present invention I
may proceed as follows reference being had to the drawings filed with the Pro-
visional Specification herein.
Fig. 1 is a cross section of my non-conducting covering applied to a pipe.
Fig. 2 is a longitudinal section through the line ay Fig. 1.
Fig. 3 is a perspective view of portion of a mould by which my pipe covering
may be formed.
Fig. 4 is a detail of portion of the mould for forming the inner portion of the
pipe covering showing such mould in reverse position.
Fig. 5 is a cross section showing an alternative form of making my non-
conducting covering.
Fig. 6 is a longitudinal section through the line ¹y Fig. 5.
In the drawings like letters of reference indicate corresponding parts in each
figure.
For producing coverings of the form illustrated or other desired curved forms
I first sprinkle advantageously upon a sheet of paper or any suitable backing
of the desired length or width to completely cover the interior of the mould Ä
mica in flakes or particles. I next sprinkle any suitable binding medium advan-
tageously silicate of soda in solution upon the mica previously superimposed
upon the sheet so that the mass now becomes soppy or spongy the silicate of

page_text: soda in solution (being very sticky) becoming mixed with the mica and the latter
becoming impregnated with such binding medium.
If desired the above steps may be repeated several times to attain the desired
thickness. This spongy or soppy layer I lift into the mould and place it in con-
centric form as indicated at B. I then fill in flake mica or mica in laminae
form C concentrically as indicated in Fig. 3 thereby forming multitudinous
air spaces c.
I may advantageously use larger flakes at the outside decreasing
in size towards the centre.
Upon the inside of the top D of the mould (either with or without laying a
sheet of paper E thereon) I place silicate of soda in solution mixed with mica to
form a layer F as hereinbefore described as to the layer C such layer F also
forming a soppy or spongy mass.
Upon the bottom of the mould previously filled as here before described I
turn the top as indicated in Fig. 3. It will thus be seen that the concentrically
formed layers already in the mould will become incorporated to some degree with
the concentrically arranged layers C herein before described similar to what the
concentrically arranged layers C will become incorporated with the layers B; the
silicate permeating in both cases into the mica particles flakes or lamina C.
This permeation or partial permeation of the concentric layers of mica C is
effected in a peculiar manner as the silicate of soda in solution in the outer
layers insinuates itself from said outer layers irregularly into the interior
strala C.
The mould after the above steps are taken is put into a furnace which pro-
duces a state of ebullition in the silicate of soda and causes the latter to permeate
the layers in an irregular manner marked b see Figs. 1 and 5 and bind the mass
together these numerous irregular projections 6 extending into the central
layers C and effectually key the mica in position and prevent lateral or longitu-
dinal displacement.
Although I describe silicate of soda as the binding and locking medium for
the mica it will be understood that any other suitable non-combustible binding
medium may be employed and the drying thereof effected in any suitable
manner.
In Figs. 3 and 4 I show the manner of making one-half of the pipe covering
and the other half shown in Fig. 1 would be made in the same manner. When
the moulds are placed together and put in the furnace or otherwise dried the
skin formed by the silicate of soda would be continuous alike around the con-
centric as well as the radial portions thereby completely encircling and enclosing
the mica in the interior.
In a covering so manufactured as I describe it may be sawn off into any
desired lengths and when placed together in halves may be covered on the
outside in the usual manner by canvas or other suitable material.
In Figs. 5 and 6 I show an alternative form in which I use a mass ("¹ of
particles of mica not necessarily concentric in fact mixed in any way.
The outer and inner layers B and F of the mica permeated with the silicate in
this case also form a series of irregular projections and f projecting inwardly
into the mass of particles and effectually serving to key the mica both from longi-
tudinal and lateral displacement. The cover is formed in this case in the
mould in the manner hereinbefore described with the exception that there are
no concentric layers.
In
This keying of the mica in position allows of multitudinous air spaces.
Fig. 1 these multitudinous air spaces are formed between the concentrically
arranged flakes as indicated and being irregular and arranged concentrically
they act like so many non-conducting deflecting plates which thereby assists
in producing the extraordinary heat non-conductivity of this covering.
In Fig. 5 in which the alternative form is shown and which of course is a
cheaper construction the dead air spaces are formed in the heterogeneously

page_text: mixed mass of particles C¹. It will thus be seen that I utilise to a maximum
extent two great non-conducting agencies viz. dead air spaces and mica.
Instead of proceeding in the manner and by the means herein before set forth
and illustrated I may produce coverings of other than curved form for instance
I may make flat or irregularly shaped non-conducting coverings of a mass of
mica flakes, lamina or particles or combinations thereof and a suitable binding
medium permeating the outer portion of such covering and forming a more Gr
less solid skin or shell thereto while the inner or interior portion of the mass
is very porous i.e. has multitudinous interstices or non-communicating air spaces
or cells therein--and same may be moulded as aforesaid or formed in any other
suitable manner.
I do not confine myself to making the aforesaid solid skin or shell (or all of
same) from mica only-as if desired I may use any other suitable material or
composition for forming said skin or shell and fill the interior of the latter with
mica either in the form of flakes or particles or both so as to thereby obtain the
object of my present invention.
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. A non-conducting covering formed of mica such covering consisting of an
inner mass of mica particles enclosed by and within an outer crust or shell
formed by the solidifying of a suitable binding material such as silicate of soda.
2. A non-conducting covering for the purposes stated-consisting of a solid
outer skin or shell constructed of mica or other suitable non-conducting material
and a binding medium such as silicate of soda with the interior space thereof
filled with mica flakes or particles whereby innumerable air spaces or cells are
formed and the latter with the mica thereby produce extraordinary heat non-
conducting properties substantially as set forth.
3. The method of forming non-conducting coverings for the purposes specified
which consists in permeating a layer or layers of mica flakes or particles with a
suitable binding medium such as silicate of soda in solution and placing same in
a mould to form the outer solid skin or shell and filling in the interior of said
skin or shell with mica flakes or particles in a dry state (i.e. without admixture
with any binding medium) and then heating the same while in the mould in
a furnace or otherwise drying same whereby the central enclosed mica is held
in position in a porous state in the said solid outer shell or skin substantially
in the manner and for the purposes hereinbefore described.
4. A non-conducting covering comprising a mass of mica particles and a suit-
able binding medium permeating the mica and maintaining it in shape and
position substantially as and for the purpose specified.
5. A non-conducting covering comprising a mass of mica particles and a suit-
able medium permeating the outer portion thereof so as to be incorporated with
the outer portion of the particles and there solidified and thereby maintain the
same in shape conformable to the surface to be covered substantially as and for
the purposes specified.
6. A non-conducting covering comprising concentrically arranged flakes or
laminæ of mica forming multitudinous hollow non-communicating interstices
and a suitable binding medium permeating the outer portion of the layers and
forming at the interior an irregularly incorporated mass whereby the cover is
held together substantially as and for the purpose specified.
7. A non-conducting covering comprising concentrically arranged flakes or
lamina of mica forming multitudinous hollow non-communicating interstices
and silicate of soda incorporated into the outer concentric flakes of mica and
forming irregular projections into the interior whereby the laminæ are keyed or
held in place substantially as and for the purpose specified.

page_text: 8. A non-conducting covering comprising concentrically arranged flakes or
laminæ of mica forming multitudinous hollow non-communicating interstices
and arranged with the larger flakes to the exterior and decreasing in size to the
interior of the covering and a suitable binding medium permeating the outer
portion of the layers and forming at the interior an irregularly incorporated mass
whereby the cover is held together substantially as and for the purpose specified.
9. A heat non-conducting covering comprising the major concentrically
arranged flakes or lamina of mica forming multitudinous air spaces the minute
finer flakes at the outer and inner sides of the covering and incorporated bind-
ing material permeating the outer flakes and extending irregularly into
inner flakes so as to hold the cover together substantially as and for the purpose
specified.
the
10. A sectional covering comprising lamina of mica with insinuating binding
material at the outside and inside of the same and on the adjacent abutting
edges of the covering whereby the sections of such covering are maintained in
shape and fitted together substantially as and for the purpose specified.
11. A method of forming a non-conducting covering for boilers and the like
consisting in spreading upon suitable backings for the outer and inner portions
of the covering a composition comprising a damp or wet binding medium inter-
mixed with mica particles superimposing upon the outer portion the concentric
flakes or laminæ of mica placing the inner and outer portions together to enclose
the central lamina and finally subjecting the whole to a suitable drying or
solidifying process whereby the binding medium is hardened and permeates into
the mass substantially as and for the purpose specified.
1000
TONGUE & BIRKBECK,
Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.