Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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The present invention applies to the art of securing insulation
to the walls of furnaces, kilns, soaking pits and the like and, more
particularly, to securing a combination insulation blanket and modular
block insula~ion to the inner walls of such structures.
Several years ago, the pre~om;n~nt method of insulating such
heating apparatus as furnaces, incinera~ors and other devices of that nature
was to use the heretofore conventional and well-known firebrick. The
process of bricking the heated areas was expensive from a labor standpoint
and extremely time consuming. Additionally, repair and replacement of
the brick lining in such structures was both expensive and time consuming.
More recent developments in the art of insulating furnaces and
such structures involve th~ utilization of insulating blankets formed of
ceramic materials or ceramic glass such as alumina. These blankets come in
varying thicknesses from 1 to 3 inches and are formed into rolls of
varying widths.
During the insulating process, the blankets are applied to the
walls of the structure in layers of anywhere from 1 to 3 layers and often
in a crisscross pattern. The blankets may be secured to the ~alls of the
furnace o~ other structure in a number of different ways.
In nearly all heating devices such as furnaces and the like, the
wall to which the blankets are supported is a metallic wall known as the
cold wall. One manner of securing the blankets to the cold wall is the
utilization of a threaded fastener which employs a drill point and self tapping
combination on the end of the fastener. The fastener is drilled and threaded
into the wall and projects outward from the wall. A number of these fasteners
are spaced along the wall and blankets impaled upon the fasteners. Thereafter,
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a washer and nut are applied to the threaded ~astener to pull the bla~ket
down into secured position.
Another device which is used ~or smaller blanke~s is a pin which
has a large washer secured on the end of the pin. The pin is pushed through
the blanket and against the metallic cold wall and stud welded in place to
secure the blanket.
A third device in prevalent use is a stud and washer combination
wherein the stud includes a plurality of tapered notches. The studs are
welded ~o the cold wall in a given array or fashion and the blanket impaled
upon the studs. Thereafter, the washers, which have a complementary aperture
therein, are placed over the stud to compress the blanket and rotated 90
and released whereupon the blanket brings the washer into locking engagement
with the stud.
These blanket insulating systems have certain drawbacks. One cf
them is that the fastening means ~or securing the blankets in place constitute
what is called an exposed system, i.e. the outermost ends of the retaining
means are exposed to the heat. This often results in burning off o the
retaining means and consequent loosening o the blanket. Another drawback
of ths blanket system is that the blankets generally are not made in thicknesses
in excess of 3 inches. Accordingly, if an insulation depth Qf several inches
is required, e.g. as high as 12 inches, then many blankets mus~ be crisscrossed
over one another to acquire the required depth. This is costly and ~ime
consuming.
A more recent development in the industry is the utili~ation of what
are known as modular insulation blocks. ~lese blocks generally come in
configllrations o 1 foot square and can range in depths rom 4 to 12 inches.
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One advantage of the modular blocks is that the required depth can be
obtained in the single installation. Additionally the blocks may be of
varying densi~y, i.e. higher density and greater insulating qualities toward
the hot face than back toward the cold face.
The modular blocks may be secured to the wall of the furnace or
the like in a number of ways. One type of re~aining device is a wire retainer
that is shaped in an H configuration which has four projecting prongs inter-
connected to a central portion. The central portion has an offset portion
which is welded to the cold wall of the furnace. A given modular insulation
block is im~aled upon a pair of the prongs. Thereafter, a next H co~figured
device is shoved into the opposite wall of the block and welded in place
followed by another block being placed upon the opposing projecting pair of
prongs. The process is repeated until a plurality of blocks form the
modular block wall.
Another me~hod of securing the modular insulation blocks is to
utilize a metallic expanded metal backing on the blocks. The blocks are
positioned in place against the wall of the furnace with ~he expanded metal
against the furnace wall. Thereafter, a collar stud is pushed through the
block into contact with the expanded metal and furnace wall and stud welded
to secure the modular block in place. Additionally, self tapping threaded
members may be employed which are pushed through the block and drilled and
threaded into the wall of the furnace. Thereafter, a washer and nut are
placed on the threaded member and tightened against the expanded metal to
hold the blocks in place.
The advantages of the modular blocks over the insulation blankets
are the ease of assembly and the ability to obtain the required insulation
thickness quickly. Additionally, the fastening systems used for the modular
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blocks are not exposed to the hot face and the likelihood of burnoff of the
retaining device is substantially less. However, there are certain drawbacks
also. One of the drawbacks is that the modular blocks are subject to a
certain amount of shrinkage upon heating. As this shrinkage occurs, the
interface between adjacent blocks may open permitting heat to migrate between
the blocks with possible damagc to the cold ~ace of the furnace. Additionally,
this possible opening at the interace of the blocks often permits passage of
corrosive vapors and the like to tha cold face of ~he furnace.
There are many applications in the industry wherein the advantages
of both the insulating blanket and the modular blocks can be efectively
taken advan~age of. For example, it would be advantageous to have 1 or 2
layers of insulating blanket crisscrossed covered with a vapor barrier to
provide the advantages of to~al integrity of the system against penetration
of heat and vapors through the insulation. At the same time, the advantages of
the modular blocks may be had by applying the blocks to the outer surface of
the insulation blanke~s and vapor barrier wherein the modular blocks add the
advantage of factory controlled blocks of varying density and the ability to
build to the desired thickness quickly, efficiently and inexpensively.
A combination insulation blanket-vapor barrier-modular blocX
system is needed b~ the industry but has been unobtainable or impractical
heretofore. The H anchors heretofore utilized to secure the modular blocks
cannot be used with the blanket or vapor barriers inasmuch as the blanket and/or
vapor barriers cannot be impaled over the H configured retaining devices.
In a like manner, the stud welding method of securing the insulation
blocks in place cannot be used inasmuch as the back surface of the insulation
bloc~ in such a combination will not be against a metallic co]d face of the
furnace. Additionally, the self tapping threaded fasteners are not practical
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since their initial concept of usage is to drill, tap and secure the
modular block once ~he block is in place, which does not provide any way for
securing the blanke~ and vapor barrier prior to placing of the blocks. It
would be impractical to drill and tap the threaded devices prior to installing
of the modular blocks, in tha~ alignment and threading of the nut and washers
to the device thereafter would require a separate operation and be ~ime
consuming and costly.
Summary of the Invention
The present invention provides apparatus and methods for retaining
modular insulation blocks and also an insulation system utilizing methods
and apparatus which provide a combination insulation blanket-vapor barrier-
modular insulation block insulating system for use in furnaces, kilns and the
like.
Specifically, the invention provides in insulation systems for
insulating structures such as furnaces, kilns and the like wherein modular
insulation blocks having top and bottom faces and side walls are secured in
side by side relationship with one face against the metallic walls of the
structure by insulation block retaining means, the improvements in the
insulation blcck retaining means comprising:
~0 an elongate end weldable stud adapted to be welded to the metallic
walls of the structure to be insulated and projecting therefrom adjacent a
side wall of a given insulation bIock;
an elongate block retaining pin; and
interlocking means permitting the retaining pin to interlock with
the stud while engaging and retaining the block.
From another aspect, the invention provides the method of securing
a plurality of rectangular insulation blocks to the metallic surface of
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structures such as kilns, furnaces and the like comprising:
welding a plurality of elongate end weldable studs having an
aperture therein to the metallic wall in a fixed upstanding array approximating
one dimension of the insulating blocks;
inserting an elongate block retaining pin having a notch approximately
midway thereof into the aperture of the stud to the point of the notch and
rotating the pin into interlocking relationship with the stud;
impaling a block by its side ~all upon the retaining pin and
positioning the block between adjacent studs;
inserting a further retaining pin into the aperture of the adjacent
stud while piercing the side wall of the insulating block to the point of
the notch and rotaking the retaining pin into interlocking relationship with
the stud~ and
repeating the s~eps of placing of adjacent blocks and inserting
the retaining pins to construct a modular insulating wall.
If an insulation blanket and vapor barrier are used, the insulation
blanket or blankets are impaled upon the studs in a crisscross fashion and
the vapor barrier likewise impaled upon the studs and placed against the
outermost insulation blanket. A refractory seal is placed around the vapor
barrier at the point where the stud pierces the vapor barrier to provide a
vapor seal.
The block re~;n;ng pin is preferably an elongate flat pin with
opposed notches generally midway of the pin. The retaining pin is slid into
the aperture of the stud to the point of the notches. The configuration of
the notches and the aperture is such that the pin can be rotated 90 in the
aperture past a slight interference fit and thus interlock with the stud
against further translational movement of the retaining pin relative to the
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stud.
Following positioning o-f the retaining pin with the stud, an
insulation block is impaled upon the retaining pin at one of its side faces
and the opposing side face pushed down in~o engagement with the adjacen~
stud. Thereafter, a further retaining pin is passed through the aperture
in the stud piercing the opposing side wall of the modular insulation block
until the notches reach the aperture. Thereafter, the retaining pin is
rotated into locking engagement with the stud.
The process is continued on a block by block basis until the
sur~ace to be insulated has been fully covered with the combination insulation
blanket-vapor barrier-modular insulation block assembly.
The invention will further be described, by way of example only,
with reerence to the accompanying drawings, wherein:-
Figure 1 is a perspective view o the stud and retaining pin o
the present invention in relation to the wall of the furnace;
Figure 2 is a perspective view o two laye~s of insulation blanket
and vapor barrier in position upon the studs and prior to interlock of the
retaining pin with the studs;
Figure 3 is a perspective view of the assembled combination of two
layers of insulation blanket, vapor barrier and a modular insulating block in
place upon a first stud and interlocked retaining pin;
Figure 4 is a sectional view of the retaining pin interlocked with
the aperture of the stud;
Figure 5 is a perspective view of the assembly of Figure 3
illustrating the placement o~ a second retaining pin into a given modular
insulating block; and
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Figure 6 is a perspective view of a series of modular insulating
blocks in place upon a dual insulation blanket and vapor barrier.
Figures 1-6 of the drawings illustrate the insulation system of
the present invention which utilizes the combination of an insulation blanket,
vapor barrier and insulating modular block as well as the retaining apparatus
for retaining the insulation system.
The retaining apparatus for the system is best shown in Figures
] and 4 of the drawings and consists of an elongate end weldable stud 10 and
an elongate block retaining pin 11.
The stud 10 includes a first end ~hereof 12 which is adapted to be
welded by the stud end welding technique to the metal cold face 13 of a
furnace, kiln or the like as shown in Figure 1. The stud 10 is preferably
of a rectangular 1at cross section.
An aperture 14 is punched or otherwise formed at the opposite end 15
of the stud. The aperture is an elongate rectangular aperture.
The elongate block retaining pin 11 is generally of a flat rectangular
cross section. Each end 16 of the pin is cut off at a diagonal angle to
provide a sharp point. Midway of the pin 11 are a pair o opposed notches 17
cut or otherwise formed into the reta;n;ng pin. A singular notch can also be
used if desired.
The cross section of the aperture 14 is essentially complementary
but slightly larger than the cross section of the retaining pin 11. In this
manner, the retaining pin may pass through the aperture when aligned with
the aperture as shown in Figures 1, 2 and 5.
The notches 17 are formed into the retaining pin of a depth such
that the diagonal distance of the remaining center portion 18 is slightly in
excess of the shorter dimension of the rectangular aperture 14. As
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illustrated in Pigure 4, the retaining pin 11 may pass through the aperture
14 to the point of the notches 17. At this time, the retaining pin 11 is
rotated until the diagonal distance of the center section 18 engages the
longer sides of the aperture 14. Continued rotation of the retaining pin 11
will permit deflection of the side walls 19 of the aperture 14 permitting the
interference to be overcome and the retaining pin 11 to snap into interlocked
relationship with the stud at the point of 90 of rotation. In this manner,
as shown in Figure 4, the re~aining pin 11 is interlocked with the stud 10
against translational movement in the aperture.
In assembling ~he system, a plurality of studs 10 are welded
in an array spaced apart the wid~h of the modular insulating block 20 as
shown in Figures 1-3. Following welding of the studs 10 to the cold face 13
of the furnace, the number of desired insulation blankets 21 are impaled upon
the studs 10. Whère two or more insulation blankets are utili~ed, they will
be generally crisscrossed, i.e. turned at 90 directions to one another to
provide closing of the edges of the rolls of the blanket.
Following placement of the blanket upon the studs and against the
cold face 13, a vapor barrier 22 is likewise positioned by being impaled upon
the studs 10. Once the insulation blanket 22 is in place, an appropriate
sealing material 23 is placed around the point where the studs 10 pierce
the vapor barrier.
Once the insulation blankets and vapor barrier and sealant are in
place, the modular insulation blocks are next assembled in place. This is
begun by taking a first retaining pin 11 and passing it through the aperture
14 of the stud 10 and interlocking it into place as shown in Figure 3 of the
drawings. Next, the block is compressed against the blankets and vapor barrier
with a slight pressure to compress the blanket to provide resiliency to the
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system. Thereafter, the insulation block 20 is then impaled upon the
retaining pin 11. It is to be noted ~hat the retaining pin 11, when inter-
locked with the stud 10, is somewhat free such that the pin may be inclined
slightly outwardly from the furnace wall to facilitate impaling of the
insulation block 20 through its side wall 24 upon the retaining pin at an
inclined angle to provide clearance of the insulating block 20 with the
adjacent stud 10. Once the insulation block is impaled upon the retaining
pin 11 with its right-hand side wall 24 against the stud 10, the block is
pushed into place with its left-hand side wall 24 against the adjacent stud 10.
As shown in Figure 5, once the insulation block 20 is in place,
a ~urther retaining pin 11 is passed through the aperture 14 of the adjacent
stud 10 pie~cing the left-hand side wall 2~ of the insulation block 20 to
the point at which the notches encounter the aperture. Thereafter, the
ret~;n;ng pin 11 is rotated 90 into interlocking engagement with the adjacent
stud lO thus completing the securing of a given insulating block 20.
The foregoing procedures are repeated for the next adjacent block in a
row as shown in Figure 6. In this manner9 row after row of blocks spaced
one upon another may be assembled to provide a combined insulating blanket-
vapor barrier-modular insulating block combination.
While the appara~us for retaining the modular blocks has been shown in
combination with the insulation blankets, the apparatus including the stud and
retaining pin may equally be ~sed for retaining modular insulating blocks alone
without insulating blankets and vapor barriers.
In a given embodiment and by way of example cnly, the insulation
blankets may be of approximately 1 inch thickness each and formed of a fibrous
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alumina glass. The insulation material comes in rolls of 18 inches in
width and 25feet in length. The vapor barrier may be o either an aluminum
foil or of a s~ainless steel foil. The sealant between the studs and vapor
barrier may be sodium silicate and clay. The insulation block is of a 1 foot
square configuration and may range in thickness from 4 inches to 12 inches
and is likewise formed of alumina.
The stud is formed of a stainless steel material and of a cross
section of .375 inches x .125 inches. The length of the stud will depend upon
the combined thicknesses of the insulation blankets and/or modular blocks
and be of length slightly less than the combined thickness.
The retaining pin is formed of a stainless steel material. The
cross section of the retaining pin is .250 inches x .125 inches. The notches
are cut into the retaining pin to a depth to leave the center portion of a
diagnonal distance presenting approximately .011 inches interference.
Rotation of the retaining pin ~or interlock within the aperture
of the stud may be accomplished by any suitable tool. An unwelded stud
itsel may be used as a convenient tool when slid partially upon the retaining
pin to provide the necessary leverage for rotation.
The insulation system. apparatus for securing same and methods of
securing same have been described in respect to the particular embodiments set
forth in the specification and as shown in the drawings. No limitation as to the
scope of the invention is intended by the description thereo~ in respect to the
particular embodiments set forth in the specification and the drawings but the
scope o the invention is to be interpreted in view of the appended claims.
