Note: Descriptions are shown in the official language in which they were submitted.
~ '7~ ~ -
This invention relates to precast reinforced insulating
members for use as a covering for furnace pipes and a method of
manufacturing same.
Numerous attempts have been made to provide an effective
furnace pipe insulation for furnace~such as the reheating furnaces
used in the iron and steel industry. United States Patents
3,149~02 dated September 22, 1964 and 3,168,297 dated February
2, 1965 describe one form of pipe insulation and method of producing
same. In this structure, coiled reinforcing members are secured
with respect to the pipe which is to be insulated by means of tie
wires which extend therethrough. By reason of the fact that
tie wires are used to secure the coils, it is necessary to apply
the insulating material about the furnace pipes in situ. This
i8 a time consuming operation in which it is difficult to maintain
quality control. An alternative form of insulation in which the
components are precast is described in U. S. Patent 3,781,167
dated December 25, 1973. The disadvantage of this structure is
that is is necessary to prefabricate the ~nforcing metal core
and this i8 a time consuming operation. The greater the number
of V-shaped members which are used, the greater the effectiveness
of the ~nforcing insert. However, the greater the number of
V-~haped numbers which are used, the greater the time required
in order to prefabricate the reinforcement and therefore, the
greater the cost of the reinforcement.
U. S. Patent 2,693,352 disclose~ a further form of furnace
insulation in which a woven wire fabric is used to form the
reinforcement. This fabric has only a limited penetration into
the depth of the insulating material and, consequently, has only
a limited efficiency as a reinforcing material.
The present invention overcomes the difficulties of the
prior art described above and provides a structure which permits
reinforcing coil members to be used as a reinforcement in a pre-
~7~
cast insulating member.
SUMWARY OF INVENTION
According to one aspect of the present invention,
there is provided a precast reinforced insulating member for use
as a covering for a furnace pipe comprising, a body of insulating
material having an arcuate shaped inner ~urface adapted to extend
in intimate contact with the surface of a furnace tube in use,
an outer surface, a pair of transverse ~ide spaces extending
from the inner arcuate surface to the outer surface and longitudi-
nally of the body, and a pair of oppositely disposed end faces,a plurality of reinforcing coil members embedded in said body
and extending circumferentially thereof at longitudinally spaced
intervals along the length of the body, each of said coil members
having oppositely disposed ends thereof disposed adjacent opposite
side faces of said body, passage means openingt~lDugh said body
between said inner arcuate surface and said outer surface thereof
adjacent each end of said reinforcing coil member, weldable lug
means secured to each end of each reinforcing coil member and
pro~ecting into each pas~age means in a plane disposed adjacent
to and substantially parallel to said inner arcuate surface whereby
a substantial portion of each weldable lug means i8 disposed in
weldable proximity to a furnace pipe and is accessible through
said pas~age means when the insulating member is operably located
about a furnace pipe in use.
According to a further aspect of the present invention,
there is provided a method of manufacturing a precast reinforcing :
insulating member foruse a~ a covering for a furnace pipe com-
~ prising the steps of, securing a pair of w~ldable lugs to opposite
ends of each of a plurality of reinforcing coil members, extending
said coil members about a convex arcuate section of a first com-
. ponent of a mould and releasably securing said weldable lugs with
: respect to said first component of the mould to mount said coil
.
--2--
.. . ... . .
. .
~ 7 ~
members in said extended position on the fir~t component of the
mould, enclo~ing ~aid coil member~ by mean~ of a ~econd mould
component to form ~ mould cavity between the fir~t and ~econd
mould components within which snid reinforcing coil member~ are
located at longitudinally spaced intervals, casting reinforcing
insulating material into the uld cavity to form a body of
insulating material encasing said reinforcing coil members and
conforming to the configuration of said mould cavity, allowing
the cast material to set and opening the mould and releasing the
weldable lug~ from the first mould component and removing the
precast reinforcing member therefrom
The invention will be more clearly understood after
reference to the following detailed specification read in con-
junction with the drawing~ wherein,
Figure 1 is a pictorial view of a reinforcing coil member
according to an embodiment of the pre~ent inventions
; Figure 2 is an exploded view of a mould for use in the
forming of a pair of arcuate haped reinforcing members;
Figure 3 i- a sectional plan view of an assembled mould;
Figure 4 is a partially sectioned pictorial view
illustrating the structure of the in~ulating members and the
manner in which they are ~ecured with respect to the pipe, and
Figure 5 i~ a ectional end view of a precast reinforced
in~ulating member according to an embodiment of the present
invention
With r~ference to Figure 1 of the drawings, reference
numeral 10 refers generally to a reinforcing coil member according
to an embodiment of the present invention The coil member consi-t~
of a coil spring 12 and a pair of weldable lugs in the form of
eye-bolt members 14 The eye-bolt members 14 each have a leg
portion 16 which extends into the coil member 12 and is welded
as ~hown at 18 to three turns of the coil Preferably, the -
- 3-
lO~S751
reinforcing coil 12 is made from stainless steel coated with
BITUMASTIC. It has been found that a stainless steel coil
spring type .109 GA 310 SS of 1~ outside diameter may be used
as a reinforcing element for an insulating member suitable for
use in association with a furnace pipe measuring 2" in diameter
or more, generally in the range of 2" to 6n. Preferably, the
eye-bolt members 14 are made from stainless steel and are of
a thickness so as to be readily weldable to the furnace pipe.
Generally, the eye-bolt will have a diameter of about twice the
diameter of the turns of the coil spring. The arm portion 16 of
the eye-bolt being secured to three adjacent turns of the spring
serves to prevent all of the load which is transferred from the
eye-bolt to the spring in use being applied to the last turn of
the spring. In this respect, the use of an independent member
which can be secured to more than one turn of the spring makes
the reinforcemeDt considerably stronger than would be the case
if the last turn of the spring was used as a connecting piece
connecting the coil spring directly to the furnace pipe. In
addition, it will be noted that the eye-bolts 14 extend in a plane
which i9 substantially parallel to the plane of the face of the
coil spring which is located at the innermost arcuate face of the
precast reinforced insulating members. This ensures that the
;~ eye-bolt 14 presents a substantial surface area towards the
furnace pipe to which it is to be welded in use.
Figures 2 and 3 of the drawings serve to illustrate the
structure of the mould in which the insulating members are formed
and the method of manufacture thereof. With reference to Figure
; 2 of the drawings, the reference numeral 20 refers generally to
the mould in which the insulating members are formed. The mould
consists of a base 22 upon which a cylindrical shaped core member
24 is mounted. A pair ~ rectangular shaped flange members 26
project radially outwardly from the core 24 at diagonally opposed
.
,
;57~L
locations on the periphery thereof. The cylindrical core member
is formed with passages 28 opening therethrough to receive four
elongated pins 30. The passages 28 are arranged in sets of two
on either side of the flanges 26 and the pins 30 are proportioned
to project through the passages 28 and to extend outwardly from
the core member 24. A pair of mould members 32 are provided for
use in association with the core member 24. The mould members 32
each consist of an arcuate shaped inner liner 34 and a backing
support frame 36. The mould members 32 each have longitudinal
side faces 38 adapted to abut one another to form a moulding
cavity about the core member 24 which is divided into two distinct
chambers by the radially extending flange members 26. Notches 40
are formed in the end faces of each mould section to provide
clearance for the pins 30 to project outwardly therefrom in use.
To assemble the mould, one of the pins 30 is threaded
through one eye-bolt 14. The pin 30 is then driven through a first
passage 28 and out of its associated second passage 28. The coil
spring member 12 is stretched 80 that the opposite eye 14 is
located over the end of the pin 30 which is protruding from its
associated passage 28. The pin 30 is then driven further through
the passage 28 so that it projects an equal distance from opposite
sides of the core member 24. This process is repeated until all
of the required reinforcing coil members are located in the mould.
In the embodiment illustrated in Figures 2 and 3 of the drawings,
four reinforcing members are provided, two being located on each
side of the mould. The mould members 32 are then positioned about
the core 24. The uld cavity is then filled with insulating
material of a type suitable for use in association with furnace
pipes. A material suitable for this purpose is a high alumina
castable refractory concrete such as that identified by the trade
mark PLICAST and available from Plibrico(Canada) Limited. Preferably,
stainless steel needles in the amount of 2% by weight are added
~. ; ~ :
... ,. , . , ~
~ 0~S~5~L
to the refractory concrete prior to casting The concrete i~
then permitted to ~et After l~etting, the mould sections 32
may be removed ~ho pins 30 are then withdrawn and two sections
of precast reinforced insulating material are ~hen removod from
the mould
Figure 4 of the drawings diagrammat$cally illustrat~s
two precast reinforcing insulating member~ 40 made in the mould
illustrated in Figures 2 and 3 of the drawings As shown in
Figure 4, the members 40 each have an arcuate shaped inner surface ~ -
- 10 42 and an arcuate shaped outer surface 44 The body of insulating
material 40 also has a pair of transver-ely extending side faces
46 which extend longitudinally thereof and a pair of oppositely
disposed end faces 48 Passage~ 50 open inwardly from the trans-
verse surfaces 46 of the body of in~ulating material such that ~ -
the eye members 14 of the coil springs 12 are expos-d and
acces~ible from the exterior of the body through the passage~ 50
to be welded, as ~hown at 52, to a furnace pipe 54 in u~e The
bar~ 30 which are u~ed to secure the oye-bolt members 14 with
reJpect to the mould during the moulding operation form the
20 pa--ageJ 50 in the mouIded body of insulating material ~ -
To install the preca~t reinforced insulating members
on a pipe 54, they are placed about the pipe 54 as hown in
Figure 4 A plurality of preca~t reinforced in~ulating members
may be mountod on the pipe 54 and temporarily ~ecured in a position
extending entirely around the pipe by an adhe~ive tape or th~ -
like Preferably, when a pipe i8 to be completely encirolod by
in-ulating material two arcuate shaped bodies of insulating
material aro locat d about the pipe and aligned with one another
as shown in Figure 4, with the passago- 50 of one body aligned
30 with the passages S0 of the other body o that they combine to
form a larger pa~age. The eyes 1~, of the bolt- are then welded
to the tube 54 by passing a welding rod or the like through the
pas~age 50
6--
., , . . -~.
~ 5~ ~ >
A~ shown in Figure S of the drawings, the eye member~ 14
are arranged to extend in a plane adjacent to the plane of the
concave inner surface 42 of tho body of insulating ~aterial 40
~his arrangement en~uros that the eye members 14 will be located
in a closely adjacent face-to-face relationship with the pipe 54
in use 80 a~ to be easily welded to the pipe whon the weight of
the body of insulating material i~ tran~mitted to the pipe 54
through the eyes 14 As previously indicated, the eye~ 14 are
welded to a plurality of turns of the coil spring 12, as shown
at 18 ~o tha~ the load transfer i8 distributed over a substantial
length of the coil ~pring member 12 ~ -
From the forogoing, it will be apparent that the
present invention provides a simple and inexpensive precast
reinforced insulating member and a method of manufacturing same ~ ~
Tho reinforcement is distributed through a substantial thicknos- -
of the body of insulating material by reason of the fact that the
reinforcing member is in the form of a coil spring The ~pring
i i8 ecured in the mould in which the insulating material is cast
by the u-e of simple mounting pins The reinforcing coil is
secured with respect to the furnace pipe by mean~ of w~dable
lug~ secured at opposite ends of the coil which are ~haped and
proportioned to be easily welded to the furnace pipe in u~e
From the foregoing, it will be apparent that the present
invention combine~ the advantages of a coil spring type of
structural reinforcement and the advantage- of a precast structure
by modifying the coil ~pring reinforcement 80 that it may be
radily welded directly to a furnace pipe in use to support the li
! precast body of insulated material on the pipe
Various modifications of the pre-ent invention will be
apparent to those skilled in the art without doparting from the
cope of the invention For example, the eye-bolt members 14
may be replaced by an alternative form of we~dable lug, such as
;;
7 _ ,!
~,........... . .
"'`' , ' : '
.~ .' ' . ,
7~
a flat strap of stainless steel material. ~t will also be
apparent that moce than two reinforcing coils may be located
in any one length of reinforced insulating material.
In a further modification of the present invention,
the method of producing the precast member~ may be modified
~uch that a plurality of units are produced by a single mould
in a "gangH system of casting.
When the precast reinforced insulating member~ of the
present invention are u~ed to insulate skid pipes, it will be
understood that the insulating body will be located only on the
lower portion of the pipe with the upper surface thereof being
insulated by means of an additional insulating material applied
in situ.
These and other variations and modifications of the
present invention will be apparent to those skilled in the art
without departing from the scope of the invention.
- 8 -
.
.~ ~
~" ' ' ' ' .' ''~.... ,~
