THERMALLY INSULATIVE MODULES FOR LINING FURNACES OR LIKE EQUIPMENT

Abstract: A prefabricated thermally insulative bldck module (10) is formed from a ceramic fibre blanket (12) folded into a plurality of cold face folds (16) and hot face folds (14). The folded and compressed insulative blanket (12) is mounted to a support bracket (20) which secures each cold face fold (16) by means of a support rod (30) which in turn is insulated by the blanket from the heat and corrosive gases in the furnace.

Description: THERMALLY INSULATIVE MODULES FOR LINING FURNACES OR LIKE EQUIPMENT The present invention relates to thermally insulative modules for lining furnaces or like equipment. Several ceramic fibre modular designs for furnace linings presently exist. Many such modules comprise individual strips of refractory fiber blanket stacked edgewise and either cemented to an expanded metal substrate by means of ceramic cement or mortar, or held together by retainer members having a base portion running the length of the individual strips, as exemplified in US Patents Nos. 3 940 244 and 3 832 815. Other known modular designs are composed of a compressed continuous strip of pleated thermally insulative blanket with two of the outer pleats (cold face pleats) mechanically supported by its metal frame. The supports run substantially the length of the fold or pleat. The modules metal frame allows it to successively attach to the adjacent modules. Once attached, the modules are mounted to the furnace walls using studs or fastening clips affixed to the walls, as exemplified by US Patents Nos. 4 001 996 and 4 103 469. However, problems still exist with certain types of insulation modules. Ceramic fibre blankets and, therefore, the modules made thereof are not mechanically strong and must be handled with great care to avoid tearing. Ceramic fibre blanket material is known to shrink when exposed to temperatures in excess of 10930C (20000F). Known modules utilising blankets of such material for lining of furnaces have encountered difficulties caused by said shrinkage of the material. Shrinkage has caused separations between folds within a module and between modules themselves, thereby exposing the furnace shell and critical retainer members to the heat of the interior of the furnace. Shrinkage has also caused the pleats of a folded blanket configuration to unfold and hence sag since not all cold faced pleats were supported. According to the present invention there is provided a thermally insulative module for lining a furnace or like equipment, the module comprising an insulative blanket folded into a plurality of inner folds and outer folds, the module being characterised by a support bracket having a base portion and a bracket mounting member and a protected bracket retaining member at each end thereof, the plurality of outer folds of the blanket being positioned between the retaining members of the support bracket, and a fold support rod extending through the plurality of outer folds of the blanket and attached to each of the bracket retaining members. Modules forming preferred embodiments of the present invention and described hereinbelow can be used to line furnace walls and ceilings. The modules can be attached to a furnace wall or ceiling having threaded studs and/or other fastening devices. The mounting members of the bracket can have slotted ends or holes to be used in conjunction with the threaded studs. The blanket of the preferred modules is under compression before and after installation. The preferred modules resist unravelling and/or lamination of the layers of insulative blanket. The invention will now be further described, by way of illustrative and non-limiting example, with reference to the accompanying drawings, in which Figure 1 is an isometric view of a module embodying this invention; and Figure 2 is an isometric view of another module embodying this invention. Each figure of the drawings illustrates a rod-anchored, accordionfold, full-lining thermally insulative module 10 to be used for insulating a furnace or other high temperature equipment. The module 10 is preformed from a folded or pleated ceramic fibre insulating blanket 12 and a support bracket 20. folds or pleats 14 and 16 exist at the hot or inner and cold or outer faces, respectively, of the module 10. The support bracket 20 has a base 22, and also has a protected upturned retaining member 24 and a mounting member 26 at each end thereof. A pleat support rod 30 extends between the retaining members 24 of each support bracket 20. The rod 30 is threaded perpendicularly through each cold face pleat 16 and is located near the outer or cooler face of the module 10 and parallel thereto. The outer or cooler face of the module 10, also referred to as the cold face, is defined as that surface of the module which comes into contact with the furnace wall. The hot face of the module 10 is defined as that surface of the module which is exposed to the interior of the furnace. Therefore, the module 10 has both hot face or inner folds or pleats 14 and cold face or outer folds or pleats 16. The pleat support rod 30 not only holds the ceramic fibre blanket 12 in compression, but also serves to retain each pleat 16 within the module 10. Each end of the pleat support rod 30 is attached to a support bracket retaining member 24. Each retaining member 24 is situated between an outer fold and end flap of the module, whereby the member 24 is protected from the -detrimental effects of the furnace environment. Any conventional means of attachment can be used. However, the rod 30 will typically be end-threaded so that a nut at each end of the rod will keep the rod secured to the support bracket 20. The folded ceramic fibre insulating blanket 12 is formed from a suitable commercially available ceramic fibre sheet such as the type known under the trademark KAOWOOL and sold by The Babcock de Wilcox Company. It should be understood that the particular type of insulating blanket used is selected in accordance with the range of temperatures in the high temperature equipment in which the apparatus is to be installed. The folded blanket 12 is compressed prior to being placed within the support members 24 of the support bracket 20. This compression is calculated to compensate for thermal shrinkage of the blanket material that occurs during use of the module. Banding material (not shown) is then placed around the module 10 at or near the two ends so that the banding material is in parallel relationship with the support rod 30. The banding material ensures that the folds and end flaps of the module remain substantially square and compressed during package, shipping and placement. Once installation of the furnace wall or ceiling is complete, the banding material is removed. A modular block fibre lining formed from a plurality of the modules 10 is typically installed in parquet fashion such that adjacent modules are turned 900 before installation. The present modular design represents a full furnace lining and as such can be used alone. However, if desired, a safety or backup liner layer of wallpaper insulation blanket can be used behind the module as further protection for the furnace shell. In both the illustrated embodiments the mounting members 26 are end-slotted. The mounting members 26 may instead each have at least one hole therein. In all cases, the members 26 are preferably sized to accept threaded studs (not shown) mounted to the furnace.

Claims: CLAIMS 1. A thermally insulative module for lining a furnace or like equipment, the module (10) comprising an insulative blanket (12) folded into a plurality of inner folds (14) and outer folds (16), the module (10) being characterised by a support bracket (20) having a base portion (22) and a bracket mounting member (26) and a protected bracket retaining member (24) at each end thereof, the plurality of outer folds (16) of the blanket (12) being positioned between the retaining members (24) of the support bracket (20), and a fold support rod (30) extending through the plurality of outer folds (16) of the blanket (12) and attached to each of the bracket retaining members (24). 2. A module according to claim 1, wherein the bracket mounting members (26) are end-slotted. 3. A module according to claim 1, wherein each bracket mounting member (26) has at least one hole therein. 4. A module according to claim 1, claim 2 or claim 3, wherein each bracket mounting member (26) is sized to accept threaded studs mounted to a furnace or like equipment. 5. A module according to any one of the preceding claims, wherein the plurality of outer folds (16) is compressed within the two retaining members (24). 6. A lining for a furnace or like equipment, the lining comprising a plurality of modules (10) according to any one of the preceding claims and an attachment means securing each mounting member (26) of each module (10) to the furnace or like equipment, adjacent modules (10) being mounted such that the plurality of inner folds (14) of one module is in compressive contact with the plurality of inner folds (14) of each of a plurality of adjacent modules.

Inventors: FERGUSON, ALAN CORBETT, GORDON, MELVIN LEON, OXFORD, ROGER CHARLES
Applicants: THE BABCOCK & WILCOX COMPANY
Application year: 1982
Main classification: F27D1
IPC codes: E04B1, F27D1