US20140190094A1

US20140190094A1 - Method and Apparatus for Insulating Panels

Info

Publication number: US20140190094A1
Application number: US13/738,703
Authority: US
Inventors: Marcio Gerep
Original assignee: Sage of America Co
Current assignee: Sage of America Co
Priority date: 2013-01-10
Filing date: 2013-01-10
Publication date: 2014-07-10

Abstract

An insulation structure attached to a wall having a multitude of anchors projecting from the wall to support the insulation structure includes a permanent refractory layer adjacent the wall and a restorable refractory layer adjacent the permanent refractory layer. An anchor supports the refractory material and includes a first stud and a second stud. The second stud includes a cap connected to a shaft, wherein the cap defines an indentation on a side of the cap opposite the shaft. The second stud receives the first stud within the indentation within the cap. The double layer of refractory material allows for maintenance and replacement of a restorable refractory layer without disturbing or replacing the permanent refractory layer.

Description

FIELD OF THE INVENTION

The invention relates to insulating water cooled panels exposed to high temperatures and/or other adverse conditions with a double layer of refractory material.

BACKGROUND

Numerous kinds of enclosures have internal surfaces that surround adverse atmospheric conditions therein, such as high temperatures, frequently oscillating temperatures, flue gases carrying abrasive particulates at high speeds, corrosive fluids, and the like. One example is a furnace used in the steel industry for smelting iron ore and other iron yielding constituents (e.g., scrap iron and pig iron) to produce slag and molten iron. Temperatures in the furnace reach or even exceed 1600 degrees Centigrade at the peak of the chemical reactions. With molten iron and molten slag inside the furnace, the interior walls of the furnace face extraordinarily harsh conditions.
One measure used to preserve the structural integrity of the furnace walls is to install water-cooled panels between the wall structures and the furnace interior. The water cooled panels include tubes or pipes with water running therein to extend their usability. The water cooled panels, however, face the above-noted extreme conditions within the furnace and likewise need structural protection. One present way of protecting water cooled panels includes insulating the panels with refractory bricks or tiles hanging from studs projecting from the panels. Other systems include applying pegs and mechanical parts to interior furnace walls to enhance the ability of slag to cling to the water cooled panels and form an insulating layer. Even more modern approaches to insulating furnaces include lining the interior of the furnace with a layer of refractory material that is structurally and compositionally rugged such that the layer withstands the temperatures, chemical reactions, and physical abrasions that are inherent in the furnace environments. Single layers of refractory materials are applied to an interior wall (e.g., over cooling tube panels) and supported by the above noted pegs or other mechanical structures to maintain it in place. The pegs or studs are often projections emanating from the tubes, and the refractory material is applied directly onto and between the tubes by hammering, pouring, spraying, dipping or otherwise covering spaces between and over the studs providing support.
The above noted tiles, bricks, and applied insulating layer bring forth complications, however. Tiles and bricks have spaces between them and potential discontinuities that affect structural integrity. A layer of refractory material wears away, exposing the supporting material thereunder. Once the tube material is exposed, its usability becomes fairly limited. Exposing a single layer of refractory material to the conditions within a furnace yields limits the usability of the protected material as the layer itself loses its stability in case of lining failure.

BRIEF SUMMARY

In a first embodiment, an insulation structure that is attached to a wall with a multitude of anchors projecting from the wall includes a permanent refractory layer adjacent to the wall and a restorable refractory layer adjacent the permanent refractory layer.
In another embodiment, a method of insulating a wall exposed to corrosive conditions includes applying a permanent refractory layer onto the wall and applying a restorable refractory layer onto the permanent refractory layer, wherein an outer surface of the restorable refractory layer is exposed to corrosive conditions.
A third embodiment of the disclosed method entails insulating a wall exposed to adverse conditions and includes the steps of (i) attaching a first stud to the wall; (ii) attaching a second stud, having a cap and a shaft, to the first stud such that the cap of the second stud is between the first stud and the shaft of said second stud, (iii) applying a permanent refractory layer to the wall, wherein the permanent refractory layer covers at least a portion of the first stud and at least a portion of the cap of the second stud; and (iv) applying a restorable refractory layer to the permanent refractory layer.
A fourth embodiment provides an anchor for supporting refractory material insulating a wall, and the anchor includes a first stud, a second stud having a cap connected to a shaft, wherein the cap defines an indentation on a side of the cap opposite the shaft. The second stud receives the first stud within the indentation within the cap.
In yet another embodiment, an anchor is for supporting refractory material insulating a wall, and the anchor includes a cap having a stud extending from one side of the cap and a shaft extending from an opposite side of the cap.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is a prior art illustration of a water cooled panel on which refractory materials used herein may be applied.

FIG. 1B is a prior art illustration of a series of water or coolant tubes on the panel of FIG. 1A.

FIG. 2 is a plan view of a coolant tube that may be a portion of a water cooled panel and shows a double refractory layer and supporting anchors as disclosed herein.

FIG. 3A is a plan view of a first stud that may be a part of a multi-piece anchor as disclosed herein.

FIG. 3B is a plan view of a second stud that may be a part of a multi-piece anchor as disclosed herein.

FIG. 4 is a plan view of a wall or surface on which a straight first stud has been attached as part of a multi-piece anchor installation.

FIG. 5 is a plan view of a wall or surface on which an entire anchor has been installed to support refractory materials as disclosed herein.

DETAILED DESCRIPTION

The interior walls of furnaces or other enclosures often surround adverse or corrosive conditions such as high temperatures, frequent temperature oscillations, flue gases containing abrasive particulates, corrosive fluids, and the like. Terms such as “adverse conditions” and “corrosive conditions” are used to convey any conditions within an enclosure that will stress the walls or panels of a structure. The terms are used in their broadest sense and do not limit the apparatus or methods described herein. Structures that house these kinds of industrial environments must be able to withstand the chemical reactions, physical stress, and operating conditions present therein, and Reference Number (60) in the Figures of this disclosure is a general indication showing these kinds of adverse conditions without limiting the invention disclosed herein.
The structures incorporating the refractory layers disclosed herein may incorporate protective features such as water-cooled panels that cool the walls of the structure and inevitably face intensely adverse conditions. The phrase “water cooled panel” and similar descriptors are not limiting of the invention disclosed herein, as the disclosure below applies equally to coolants other than water and structures other than panels.
The water cooled panels (20) of FIG. 1A often utilize water conduits (25), such as tubes or pipe structures, allowing water or other coolants to flow there through, absorbing some of the heat energy that would otherwise deteriorate the walls of the enclosure (e.g., water cooled panels lining the walls of a furnace). As shown in FIG. 1A, the tubular members (25) of a water cooled panel include pegs or studs (30) extending substantially perpendicularly from the outer surface of the tubes (25). As noted above, these studs (30) may allow refractory tiles to hang over the water cooled panel, or the studs may provide an anchor point for slag in a steel furnace to accumulate along the wall of the furnace, thereby forming a layer of insulation protecting the panel. FIG. 1B shows a close up view of the cooling tubes associated with a water cooled panel and the studs (30) extending from each tube. The arrangements shown in FIGS. 1A and 1B may also be conducive to applying a single layer of refractory material to the water cooled panel such that the single layer refractory covers the tubes (25) and at least portions of the studs (30).
In one embodiment of the wall insulation method described herein and shown in FIG. 2, two layers of refractory are applied to a wall in a furnace or similar enclosure. The two layers of refractory may also be applied over water cooled panels and associated tubular members (25), similar to the structure shown in FIG. 1A. The double layer refractory includes a permanent refractory layer (40) and a restorable refractory layer (50) adjacent the permanent refractory layer. In another embodiment, the restorable refractory layer (50) comprises a first side (52) and a second side (53). The first side (52) is an exposed surface subject to adverse conditions (60) that wear down the exposed surface. Similarly, the permanent refractory layer (40) has a first permanent layer surface (42) and a second permanent layer surface (43). In one embodiment, shown in FIG. 2, the second side (53) of the restorable refractory layer (50) is adjacent, or even directly adjacent, the first permanent layer surface (42) of the permanent layer (40). The second permanent layer surface (43) of the permanent layer (40) is adjacent, or even directly adjacent, the wall, panel or as shown in FIG. 2, the tubular member (25) of a water cooled panel (20).
The double refractory layer (40, 50) protects a wall in a furnace or other enclosure in a manner that allows maintenance on the installation to be extremely convenient. By incorporating a restorable refractory layer (50) over a permanent refractory layer (40), the adverse conditions (60) within the enclosure, including high and fluctuating temperatures, flue gases with abrasive particulates, corrosive fluids, chemical reactions, and other harsh or corrosive parameters affect only the restorable refractory layer (40) before the wall or panel is removed for maintenance. The method of applying a permanent refractory layer (40) and a restorable refractory layer (50) provides an avenue for inspecting the insulating refractory (40, 50) when the restorable refractory layer (50) wears down to a predetermined thickness. As shown in FIG. 2, the restorable refractory layer (50) is applied atop the permanent refractory layer (40) and covers the supporting anchors (105). As the adverse conditions (60) within the enclosure wear down the restorable refractory layer (50), the tips (107) of the anchors (105) are exposed. Eventually, the restorable refractory layer (50) is exposed to a point at which the cap (90) is exposed. Without limiting the invention to any one embodiment, the wear on the restorable refractory layer (50) may remove the refractory material all the way down to the cap (90), which is an effective limit for signaling time to provide a totally safe restoration. The adverse conditions (60) also wear down the anchors (105), which can require replacement as well. In the embodiment shown in FIG. 2, a tubular member (25) of a water cooled panel utilizes the double refractory layer (40, 50) to protect the water cooled panel. When the restorable refractory layer (50) wears down or corrodes to a predetermined thickness or when the caps (90) show through the refractory layer and begin to show wear as well, the entire panel or wall section may be removed for maintenance.
The maintenance of a wall section or water cooled panel (20) as disclosed herein is significantly more expedient than prior forms of insulated walls. By insulating the wall or panel in a double refractory configuration, the corrosive conditions within the enclosure do not significantly affect the permanent refractory layer (40) installed directly adjacent the wall or panel structure. The wall or panel (25) may be removed from a furnace or other installation for repair prior to losing the entire depth of the insulating refractory (40, 50). Applying a new restorable refractory layer (50) over the original permanent refractory layer (40) is a much simpler process than building an entirely new panel with a new single layer refractory or even patching a single layer refractory.
In order to accomplish the insulation method described above, the permanent refractory layer (40) and the restorable refractory layer (50) may be made of different compositions. The refractory compositions may include, but are not limited to, carbon graphite, silicon carbide, mixtures of magnesium and silicon carbide, magnesium oxide, aluminum oxide, silicon dioxide, zirconium dioxide, titanium dioxide, chromium oxide, and alloys thereof. The selection of compositions for each refractory layer may depend upon the adverse conditions affecting the restorable refractory layer and the cost of replacing the respective refractory layers.
Utilizing a double refractory embodiment as shown in FIG. 2 may be implemented using an anchor (105). Without limiting the invention, in one embodiment, a plurality of anchors (105) extend across a furnace wall or across the tubes (25) of a water cooled panel. The anchors (105) support the refractory material (40, 50) which is applied between, around, and over the anchors (105) by methods including, but not limited to, hammering, pouring, spraying, dipping, and the like.
In one embodiment that does not limit the invention disclosed herein, the anchors (105) may include either a one piece or multi-part design, whichever is more convenient for the installation at hand. For instance, when the space between two consecutive studs does not allow the application of a single piece stud that contains the two sections in one integrated piece, then a multi-piece installation is appropriate. Ultimately, in one non-limiting embodiment of the anchor (105) shown in FIG. 2, the anchor (105) includes a cap (90) that extends substantially horizontally and divides a straight section or sections (75, 95) of the anchor (105). The cap (90) adds additional surface area for stabilizing the application of both the permanent refractory layer (40) and the restorable refractory layer (50). As shown in FIG. 2, the caps (90) provide a bracing structure holding the permanent refractory layer (40) below the cap and supporting the restorable refractory layer (50) extending from the permanent refractory layer.
A method of insulating a wall exposed to adverse or corrosive conditions may include installing the anchor (105) on a water cooled panel (i.e., on the tubes or piping system of the panel) or on a wall of an enclosure. In one embodiment, the anchor (105) is a single piece pre-fabricated device with at least one straight section or straight sections (75, 95) extending from opposite portions of a cap portion (90).
In another embodiment that does not limit the scope of the apparatuses and methods disclosed herein, the anchor (105) has a multi-part construction that is assembled as part of an installation process for insulating a wall or panel with refractory material. The multi-part assembly of an anchor (105) may include a first straight section, or first stud (75), shown in FIG. 3A, that is attachable to a wall or tubular system of a water cooled panel (20), and particularly attachable along the tubes (25). The stud (75) has a first end (77A) and a second end (77B). As shown in FIG. 3A without limiting the invention, the stud (75) may include a threaded, notched, ribbed or knurled surface that allows the refractory material used in insulating the wall to adhere to the stud (75) for support. The multi-piece construction also incorporates a second stud (80) as shown in FIG. 3B. The second stud (80) has a shaft (95) with a first shaft end (81A) and a second shaft end (81B). The second shaft end (81B) connects a cap (90), which may result in the second stud (80) having a general “mushroom” shape, or in other words, the second stud (80) has a straight portion in the shaft (95) and a transverse portion (90) that forms a substantially horizontal cap over the shaft (95). The cap (90) defines an indentation (93) on a side of the cap (90) opposite the shaft (95). The second stud (80), therefore, is configured to receive the first stud (75) within the indentation (93) within the cap (90).
The multi-piece configuration of an anchor for the refractory insulations presents a way of attaching a first end (77A) of a first stud (75) to a wall or water cooled panel (20) by a first weld (71A). See FIG. 3. The second end (77B) of the first stud (75) connects by a second weld (71B) within the indentation (93) defined by the cap (90) of the second stud (80). The overall anchor (105) is shown in FIG. 5 in the context of welding the anchor (115) to a tube (25) within a water cooled panel (20).
FIG. 5 illustrates that a refractory layer anchor (105) may incorporate a single-piece fabrication shaped to include generally straight sections (75, 95) extending from opposite sides of a cap (90). The single piece, therefore, would be attached to the wall or panel by a weld (71A) or otherwise connected to the panel at one end (77A). The same general shape for the anchor (105) may be accomplished by attaching a multi-piece embodiment according to the description above. The result is an anchor attached to a wall or panel in a corrosive environment and configured to support a refractory insulation. The anchor includes a cap portion that engages two different layers of refractory material, one permanent layer (40) of refractory material extending from the panel (20) or tube (25) toward the midsection of the cap (90) and another layer (50) extending from the permanent layer (50) and having an exposed tip (107). The straight sections (i.e., the stud (75) and the shaft (95)) may have an exterior (72) that is not entirely smooth (e.g., etched, knurled, or threaded).
One method of accomplishing a double refractory layer (40, 50) as shown in FIG. 2 includes attaching a first stud (75) to a wall or water cooling tube (25) within an enclosure that surrounds adverse or corrosive conditions. The first stud may be attached by a stud welding process or by any convenient means that is sufficient to affix the first stud (75) to the wall securely and provide total metal contact between the stud and the tube. A second stud (80) is attached to the first stud (75), and in one embodiment, the second stud (80) has a cap (90) and a shaft. The second stud (80) is attached to the first stud (75) such that the cap (90) of the second stud (80) is between the first stud (75) and the shaft (95) of the second stud (80). Overall, the first stud (75), the second stud (80), and the intermediate cap (90) between the two are attached to the interior wall or water cooled panel to support refractory layers (40, 50) described herein. Accordingly, in the method of this disclosure, a permanent refractory layer (40) is applied to the wall and covers at least a portion of the first stud (75) and at least a portion of the cap (90) of the second stud (80). The method continues with applying a restorable refractory layer (50) to the permanent refractory layer (40). The restorable refractory extends from about the midsection of the cap (90) within the anchor (105). The restorable refractory layer (50) may be flush with the tips (107) of the anchors (105) or may entirely cover the portion of the anchor (105) extending outwardly from the cap (90). In another embodiment, the restorable refractory layer (50) may exceed the length of the anchor (105) by a dimension that is between about ⅛ of an inch and ½ of an inch. When the depth of the restorable refractory layer (50) extends too far above the length of the anchor (105), then the extended portion of the restorable refractory layer (50) above the anchor (105) cannot benefit from a cooling effect provided by the anchor (105). Without a cooling effect from the anchor (105), the restorable refractory layer (50) extending over the anchor (105) will collapse.
The wall to which the refractory layers are applied may be a removable panel of cooling tubes or an entire component such as a water cooled duct, an elbow, etc., and the step of attaching the first stud (75) includes attaching at least one straight stud (75) to at least one of the cooling tubes (25) in a position that is substantially perpendicular to the cooling tube. The second stud (80) is attached to the first stud (75), and the two studs support at least two refractory layers (40, 50) insulating the wall installed in a corrosive environment. The two refractory layers (40, 50) include at least one permanent layer (40) of refractory material and at least one restorable layer (50) of refractory material. The restorable layer (50) of refractory material is exposed to conditions (60) within the enclosure that wear the restorable layer down to thicknesses that expose the anchors. Of course, exposed anchors (105) also wear down and may need to be replaced as well. The method of insulating a wall herein places a restorable layer of refractory material (50) in an outward position within an enclosure, such that the restorable layer of refractory material (50) is subject to corrosive conditions (60) within the subject enclosure. By providing a means for replenishing the restorable layer (50) without disturbing the permanent layer (40) thereunder, the permanent layer (40) may last significantly longer as does the metal wall structure protected by the double layer system. In embodiments utilizing a two piece anchor, a worn restorable layer may allow access to the second stud (80), which can be removed from the first stud (75) and replaced with a new second stud (80). Accordingly, the insulation structure and associated anchor set forth herein allows for repair of portions of the insulation or anchors according to need. Insulated installations within the ambit of this method will not require an entire re-manufacturing of the whole refractory insulation during maintenance. The maintenance of the refractory installation is therefore significantly more economical.
While specific embodiments of the invention have been illustrated and described herein, it is realized that numerous modifications and changes will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit and scope of the invention.

Claims

1. An insulation structure attached to a wall, the insulation structure comprising:

a multitude of anchors projecting from the wall and supporting the insulation structure;

a permanent refractory layer adjacent the wall; and

a restorable refractory layer adjacent said permanent refractory layer, wherein the anchors have respective caps about midway along the length of the anchors, and said permanent refractory layer extends to about the midsection of the caps.

2. An insulation structure according to claim 1, wherein a side of said restorable refractory layer, opposite said permanent refractory layer, is an exposed surface.

3. An insulation structure according to claim 1, wherein said permanent refractory layer and said restorable refractory layer comprise different compositions.

4. An insulation structure according to claim 3, wherein said compositions are selected from the group consisting of carbon graphite, silicon carbide, mixtures of magnesium and silicon carbide, magnesium oxide, aluminum oxide, silicon dioxide, zirconium dioxide, titanium dioxide, chromium oxide, and alloys thereof.

5. An insulation structure according to claim 1, wherein said permanent refractory layer extends from the wall to a midsection of the respective anchors, and said restorable refractory layer extends from said permanent refractory layer.

6. (canceled)

7. An insulation structure according to claim 1, wherein said restorable refractory layer extends from said permanent refractory layer and covers the entirety of the anchors.

8. An insulation structure according, to claim 1, wherein the wall is a removable panel of cooling tubes having a plurality of anchors extending substantially perpendicularly from the tubes, and wherein said permanent layer of refractory material covers at least a portion of the tubes.

9. A method of insulating a wall exposed to corrosive conditions, the method comprising:

applying a permanent refractory layer directly onto the wall; and applying, a restorable refractory layer directly onto said permanent refractory layer, wherein an outer surface of said restorable refractory layer is exposed to the corrosive conditions.

10. A method of insulating a wall exposed to adverse conditions, the method comprising:

attaching, a first stud to the wall;

attaching a second stud having a cap and a shaft to said first stud such that the cap of the second stud is between the first stud and the shaft of said second stud;

and after attaching said second stud to said first stud, applying a permanent refractory layer directly to the wall, said permanent refractory layer covering at least a portion of the first stud and at least a portion of the cap of the second stud; and

applying a restorable refractory layer directly to the permanent refractory layer.

11. A method of insulating a wall according to claim 10, further comprising the step of covering the entirety of the second stud with the restorable refractory layer.

12. A method of insulating a wall according to claim 11, wherein the wall is a removable panel of cooling tubes, and the step of attaching the first stud comprises attaching at least one straight stud to at least one of the cooling tubes in a position that is substantially perpendicular to the cooling tube.

13. A method of insulating a wall according to claim 10, further comprising the step of replacing at least a portion of the restorable refractory layer upon removal of the restorable layer due to the adverse conditions.

14. A method of insulating a wall according to claim 13, wherein the step of replacing at least a portion of the restorable refractory layer comprises reapplying the restorable refractory layer before the corrosive conditions affect the permanent refractory layer.

15. A method of insulating a wall according to claim 13, further comprising the step of replacing the second stud connected to the first stud prior to replacing at least a portion of the restorable refractory layer.

16-26. (canceled)