KR20020005620A - Refractory tile system for boiler tube/heat exchanger protection - Google Patents

Abstract

A refractory tile system (60) includes a barrier layer coating (61) applied to the wall (16) of a boiler. Refractory tiles (66) are then fastened to the tu be wall (16) utilizing a floating attachment mechanism (68) to provide a relatively high degree of freedom of movement relative to the tube wall to accommodate micro-scale bowing of the tile generated by the relatively large temperature gradient and mean temperature typically experienced by such tile s. Each tile (66) is also isolated from adjacent tiles by providing a predetermined gap (70) therebetween of sufficient size to effectively preven t macro-scale bowing. Moreover, a compressible fibrous mortar is disposed in t he gap between each adjacent tile to prevent contaminants from passing therethrough.

Description

Refractory tile system for boiler tube / heat exchanger protection

Refractory tiles have long been used for the protection of boiler walls in waste incinerators and other heat exchanger applications. The main function of the refractory tiles is to heat the steel alloy boiler walls, which typically comprise water wall tubes and a membrane or web disposed between them, to prevent temperature, erosion, and corrosion by the intrusion of acid vapors associated with boiler operation. to protect against corrosion. These conditions are caused by the combustion process in the boiler. For example, municipal solid waste (MSW) installations incinerate general waste and food waste to temperatures up to about 1400 ° C. To recover the effective energy generated in these MSW plants, the waste is passed through a metallic water wall tube adjacent to the furnace and converted to steam by high temperatures. The steam generated in the tube assembly is then used to drive the turbine driven electricity generator. However, MSW installations produce gaseous products that, when in contact with metal walls, chemically invade the walls. The purpose of the refractory tiles is to heat the tubes sufficiently to prevent direct intrusion of the walls by gaseous products and to generate steam efficiently. Thus, the main purpose of the tile is to extend the expected life of the tube wall.

Refractory tiles for protecting boiler tubes are typically made from materials such as silicon carbide (SiC). These tiles are generally provided with a substantially flat face having a back face of a shape and size that matches the shape of the tube wall. The tiles generally have three configurations: bolted tiles, hanging tiles as disclosed in U.S. Patent No. 4,768,447 by Roumeguere, and U.S. by Aiken et al. Modified hooks also known as slotted or T-sloted tiles as disclosed in International Publication No. WO 97/09577 by Patent 5,243,801 and Zampell Advanced Refractory Technologies, Inc. Variously manufactured as one of the modified hanging tiles. US Pat. No. 4,768,447, US Pat. No. 5,243,801 and International Publication No. WO 97/09577 are incorporated herein by reference.

As shown in FIGS. 1 and 2, the bolted tile 10 is generally provided with a square or rectangular face 12 oriented towards the interior of the boiler. A hole penetrates through the thickness of the tile approximately in the center of the face 12. Typically, there is a countersunk region 34 in the hole or bore 30 that acts as a seat for the nut 28. In a typical installation, a stud or threaded bolt 24 is welded to the membrane zone 16 between two tubes 18 in the boiler wall 62. The back side 14 of the tile 10 includes a precision portion 20 of a shape and size that allows for close contact that is receptably matched to the contour of the tube wall 19.

The tile is installed by threading the stud through the hole and screwing the washer 28 and nut 26 onto the stud to secure the tile in place. The cap (not shown) is then typically mortared over the hole to minimize the amount of gas that can flow through the gap between the standard holes for the back of the tile. A mortar layer (not shown) is typically provided between the tile and the wall 2 and between adjacent tiles, to help secure the tile in place and to substantially allow gas to flow between and / or behind the tiles. To form a rigid structure that functions to prevent it.

The advantage of using bolted tile configurations is that the tiles can be installed relatively easily and can be installed on any boiler surface, including vertical and protruding surfaces.

The disadvantage of the bolted tile is related to the breakage of the tile. Generally, such tiles have an expected life of 2 to 4 years due to stud breakage. If the stud breaks, the tile will fall off the wall, exposing the boiler tube to the incinerator atmosphere. The cause of breakage in the stud is due to high temperature acid corrosion. In particular, the acid penetrates the tiles through the stud holes and invades the studs. Corrosion is perceived as severe on studs due to high operating temperatures (above 1000 ° C). In addition, the crack of a tile is a thing which normally arises and arises by overtightening a stud.

One attempt to address the shortcomings associated with bolted tile devices has been to use hanging tiles. As shown in FIGS. 3 and 4, the hanging tile 45 typically uses an anchor / hook or short stud 37 to hang the tile on the membrane 16 of the boiler wall 62. Gravity is used to keep the tile close to the boiler wall 62 for heat exchange. This tile 45 is a variant of the bolted tile in which one or more holes 30 'protrude from the rear face 14' of the tile toward the hot face 12 but do not completely penetrate the hot face. This provides a tile with a tight surface to theoretically improve acid corrosion resistance. A mortar layer (not shown) is typically provided between the tiles 45 and the boiler wall 62 as well as between adjacent tiles to form a rigid structure that is substantially gas and ash impermeable.

A variation of this hanging tile configuration is the use of tile 45 with an air cleaning system. In this variant, no mortar is provided behind the tile to leave a gap between the tile and the boiler wall. Air flows through the gap to minimize acidic corrosion of the walls.

The advantage of the hanging tiles is that they are generally relatively easy to install and replace. A disadvantage of the hanging tile construction is that it generally cannot be installed on a non-vertical wall because the tiles tend to fall off the anchor. Tiles are also known to be lifted from anchors during operation due to thermal expansion or the like. In addition, the above-described air cleaning apparatus tends to disadvantageously increase the required cost of the tile apparatus in comparison with the configuration using mortar. Heat transfer between the tile and the wall may be adversely reduced due to the insulating (ie, relatively low thermal conductivity) nature of the air layer.

Referring to FIG. 5, a modified hanging tile 50 has been developed as an attempt to address the drawbacks associated with moving a hanging tile from an anchor or hook. Examples of such modified configurations are commonly known as mushroom bolts, tube-welded fin anchors, and T-slot tiles. These tiles 50 are bolted and hooked tiles incorporating a tile face 12 'in close contact with an anchor 52 having a substantially T-shaped contour to effectively secure the tile and install it on the vertical and protruding surfaces. Is a mixed type.

Such a tile 50 is generally installed using a mortar layer between the tile and the boiler wall and between adjacent tiles. The purpose of the mortar is to fix the tile by providing a firm attachment and to provide a barrier to prevent the penetration of ash and corrosive gases between and behind the tiles.

The advantage of this modified tile 50 is that it can be installed on any boiler surface nominally. A disadvantage of tile 50 is that it is difficult to manufacture because it incorporates blind (ie discontinuous) slots 54 that protrude laterally from the edge into the tile. In addition, the tiles may be physically weakened due to the complex structure of the blind slots 54. Also, individual tiles generally cannot be replaced without removing the entire tile row.

Another approach to address the drawbacks of the above-described configuration is to use the hanging tile 45 with an elastic material 48 installed between the opposing recesses or grooves 49 as shown in FIGS. 3 and 4. will be. This approach allows for easier installation and replacement of tiles compared to tile arrangements using conventional rigid mortars. While this approach can be used satisfactorily in some applications, the elastic material 48 provides a low corrosion resistance against adverse corrosive gas flows and tends to be undesirable, especially for use in corrosive environments as found in MSW boilers. There is this.

In addition, many of the approaches described above utilize compressible fibrous material or mortar at periodic tile spacing to function as expansion joints. For example, the material may be used every seven to fifteen tiles in a familiar manner to those skilled in the art of bricklayer (ie, as is commonly used in the manufacture of concrete walkways and the like). However, such joints disadvantageously tend to pass acid or other corrosive materials to corrode underlying boiler walls. In addition, it has been shown that the useful life of a tile device with the expansion joint is not much greater than a similar tile configuration without the expansion joint.

Accordingly, there is a need for an improved refractory tile device that addresses the drawbacks associated with the prior art.

The present invention relates to a refractory tube block that protects metallic waterwall tubes from high temperature and highly corrosive furnace gases while maintaining good thermal conductivity.

1 is a plan view of a bolted refractory tile of the prior art;

2 is a sectional view taken along line 2-2 of the fire resistant tile of FIG.

3 is a side cross-sectional view of a hanging fire resistant tile of the prior art;

4 is a front sectional view of the hanging fire resistant tile of FIG.

5 is a fragmentary, cross-sectional perspective view of a portion of a prior art modified refractory refractory tile disposed for engagement with a boiler wall;

FIG. 6 is a cross sectional view similar to FIG. 2 including a front view of one embodiment of a fire resistant tile device of the present invention;

7 is a cross-sectional view similar to FIG. 6 showing another embodiment of the fire resistant tile device of the present invention.

8 is a perspective view illustrating a fire-resistant tile arrangement of the prior art, macro-scaled as recognized in accordance with the present invention.

FIG. 9 is a schematic cross-sectional view similar to FIG. 2 showing a portion of a pair of adjacent fire resistant tiles of the prior art and showing as a virtual line deformed by bending; FIG.

10 is a view similar to FIGS. 6 and 7 showing another embodiment of the fire resistant tile device of the present invention.

FIG. 11 is a side view of a part of the refractory tile device of FIG. 10 broken away; FIG.

12 to 15 are perspective views showing various steps taken during installation of a fire resistant tile according to the invention of the fire resistant tile device of FIGS. 10 and 11;

16 is a side schematic view of a conventional series of bolted tiles of FIGS. 1 and 2 installed in a test boiler.

FIG. 17 is a graph showing test results generated by the bolted tile of FIG. 16. FIG.

18 is a graph similar to FIG. 17 showing test results generated by the tiles of the present invention.

An obvious aspect of the present invention is to recognize a problem that causes a number of breakages of prior art devices. These breaks are the warping of individual tiles (used herein as "micro-scale" bowing) and collective warping of multiple tiles (here "network" or "as shown in FIG. 8"). Macro-scale "bowing (used as" networked "or" macro-scale "bowing). Referring to FIG. 9, the micro-scale deflection generates a force F transmitted through the rigid mortar (not shown) to adjacent tiles, resulting in a macro-scale deflection effect. Macro-scale bending exerts sufficient tensile stress on the studs resulting in failure. In this regard, to date, significant dimensional instability of the tiles has been mainly limited to thermal expansion resulting from exposure to elevated boiler temperatures. In addition, any warpage was limited for the individual tiles.

In contrast, the present invention contemplates the thermal gradient that the individual tile receives during the operation of the boiler (i.e., the temperature difference between the hot surface 112 'and the rear 114', for example as shown in Figure 7). It is based on the recognition that it is larger and affects the dimensional instability of the tile more than the thermal expansion described above. It has then been realized that the warpage generated by the thermal gradient transfers the stress through the rigid mortar disposed between adjacent tiles to effectively increase the warping effect of the individual tiles as a function of the square of the length of the tile network. This phenomenon is explained by the following equation.

δ = α L ² ΔT / (8t)

Is the cumulative deviation, α is the coefficient of thermal expansion, L is the tile array length, ΔT is the temperature difference at the opposite surface of the tile, and t is the tile thickness.

It has also been found to create "hot spots" that deepen the temperature gradient across the tiles so that oxidation at the hot side of the tiles occurring over time further contributes to the micro-scale bending effect. In this regard, macro-scale warping has been found to initiate an unlimited number of repeat cycles that function to accelerate oxidation to accelerate the collapse of the tile. For example, the optimum working temperature of the hot side of SiC tiles is approximately 500 to 600 ° C. Oxidation at this temperature has been found to be minimal and substantially does not adversely affect tile life. However, it has been found that when the hot surface reaches or exceeds about 750 ° C., oxidation proceeds rapidly and rapid acceleration is maintained with further increase in temperature. Thus, an aspect of the present invention is the recognition that the macro-scale deflection functions to separate the tile from the boiler wall, thereby forming an air gap that generally reduces heat transfer from the rear of the tile to the wall. This reduction in heat transfer substantially increases the temperature in terms of high temperature beyond the good operating temperature range. As a result, macro-scale warpage has the effect of raising the temperature of the hot surface to an oxidation promoting temperature of 750 ° C. or higher. Oxidation further increases the temperature gradient as described above and further exacerbates macro-scale warpage, thus forming a sustained deleterious repeat cycle.

Thus, while prior art tile configurations have been developed to minimize acid penetration (i.e. blind holes for mounting of the hanging and deforming tiles 45, 50), the above described bending conditions are not recognized and handled at all. This conventional configuration allows the continuous use of rigid mortar around the tile, resulting in macro-scale warpage.

The failure of the expansion joints described above to generate any substantial benefit is due in part to the failure to recognize network bending phenomena and attempts to compensate only for relatively good thermal expansion effects. This failure has been pointed out not only by relatively small amounts, that is, by rare expansion joints (ie, used only once every 7 to 15 tiles), but also by the frequent use of conventional mortar disposed in at least a portion of the expansion joint.

The initial steps in developing the present invention included the completion of a first finite element model (FEM) of a conventional 18 cm x 18 cm bolted tile to check for the cause of cracking in the tile during operation. This analysis revealed the stresses present in the tiles due to the thermal gradient. The warpage of the individual tiles was revealed as a function of thermal gradient. The initial result of this analysis was to increase tile thickness to increase tile strength.

After this first analysis was completed, a second finite element model was completed to predict the thermal profile along the length of the stud through the tile thickness. At an estimated incinerator operating temperature of 1370 ° C., this model predicted the studs to react at a temperature of about 800 ° C., the maximum service temperature of most stainless steels.

The broken studs were then recovered from the incinerator. The analysis revealed that the studs were stretched approximately 6 mm before breakage. This indicated that the studs were placed under tensile load and not only destroyed by acidic corrosion but rather by stress-corrosion. Therefore, it was decided to investigate the cause of the stress on the stud phase.

It was also observed that during the recovery of the broken studs, blister areas were present in the tile. These blisters were in approximately 10 tile x 10 tile areas and were placed in the boiler.

A third finite element model was disclosed to study tile warpage and tensile stress phenomena. As mentioned above, the first FEM has shown that the warp or micro-scale warp of the individual tiles is caused by a heat gradient. However, this deflection was insufficient size (0.3 mm) to cause the 6 mm deformation observed in the studs.

For the third FEM, a 7x7 array of tiles was modeled assuming that mortar acts as a rigid material. The results of the analysis showed a network effect between the tiles that resulted in apparent warpage of 25 mm or more. In addition, stress analysis indicated that the tensile force was applied to the studs to stretch the studs to the point at which the network (macro-scale) deflection broke.

To confirm the finite element model, test panels of test tiles were installed in the furnace. The data collected from the test panel indicated that after one year of use, macro-scale tile warpage with a warpage size of about 4 mm occurred during operation. Extrapolation of the flexural speed calculates that the tile is displaced 8 mm (the amount of displacement assumed to be necessary for stud breakage) for approximately 2.5 years from the start of the test. This corresponds significantly to the operating life observation of the bolted tile.

Thus, according to an embodiment of the present invention, a refractory tile device for use in a wall of a boiler includes a plurality of tiles having a floating fastening device capable of joining the wall to keep the tiles in a spaced apart movable relationship. It includes. The tile has a shape and size that provides a gap between adjacent tiles of the tiles, the gap being configured to sufficiently accommodate the dimensional change of the tile that appears during exposure to the operating temperature of the boiler. The corrosion barrier is disposed between the tile and the wall.

In a second aspect of the invention, a refractory tile device for use in a wall of a boiler comprises a plurality of tiles disposed on the wall in a movable relationship spaced apart from each other. The tile has a shape and size that provides a gap between adjacent ones of the tiles, the gap being configured to substantially sufficiently prevent the tile from bending to macro-scale during exposure to the operating temperature of the boiler. A corrosion barrier is disposed between the tile and the wall to substantially prevent corrosion of the wall.

In a third aspect of the invention, a method for increasing the useful life of a wall of a boiler is provided. The method comprises the following steps,

(a) providing a plurality of tiles having a floating fastening device capable of engaging the walls to maintain the tiles in a movable relationship spaced apart from each other;

(b) determining the dimensions and shape of the tiles to provide a gap between adjacently mounted tiles on the wall,

(c) placing a corrosion barrier on the wall;

(d) coupling the floating fastening device to the wall, wherein the tiles overlap with the wall with a corrosion barrier in between.

These and other features and advantages of the present invention will become more apparent by reference to the following detailed description of various aspects of the invention, taken in conjunction with the accompanying drawings.

Exemplary embodiments of the invention are described in detail below with reference to the drawings described in the above description. For clarity, the same parts shown in the accompanying drawings are designated by the same reference numerals, and like parts shown in the other embodiments are designated by similar reference numbers.

As used herein, the term "axial" as used in conjunction with an element disclosed herein is such that the element engages tube 18 as shown in FIGS. 6, 7, 10, and 14. one when it is placed substantially parallel to the central axis (a) (see Fig. 7) of the tube (18), means the direction of the element. The term "lateral direction" means a direction substantially perpendicular to the axial direction.

Referring to FIG. 6, in one embodiment of the present invention, a refractory tile device 60 is applied to the wall 62 (ie, membrane 16 and tube wall 19) of the boiler of an incinerator or heat exchanger. Barrier layer coating 61. The barrier layer 61 is adapted to provide corrosion resistance to acids and salts at the normal operating temperature of the boiler. One example of such a coating is a phosphate-attached SiC barrier layer, such as PC-1022 ^™ , manufactured by Norton Company of Worcester, Mass., USA. Advantageously, such materials provide relatively good corrosion resistance and thermal conductivity. The refractory tile 66 is then fastened to the tube wall 62 using the floating attachment mechanism 68 in a superimposed manner on the wall 62. Tile 66 is known to those skilled in the art, such as, for example, silicon carbide (SiC) or other ceramic materials that can withstand temperatures experienced in boilers such as MSW incinerators / heat exchangers (approximately 1400 ° C.). Are made of any suitable refractory material.

The floating attachment mechanism 68 provides the tile 66 with a relatively high degree of freedom of movement relative to the tube wall 62 to accommodate the micro-scale deflection of the tile. As mentioned above, micro-scale warpage is caused by the relatively large temperature gradients (typically between about 200 and 600 ° C. or higher) that the tile receives. As mentioned above, this temperature gradient acts substantially greater in terms of the dimensional instability of the tile than its elevated temperature, in particular the network effect of increasing warpage as the square of the tile arrangement length. Each tile 66 is effectively isolated from adjacent tiles by providing a predetermined gap 70 between the tiles that is large enough to effectively prevent micro-scale warping caused by networking. As shown in FIG. 9, this networking phenomenon is caused by the pressure or force F exerted on each other by the tiles through the rigid mortar (not shown) when micro-scale bending occurs.

Referring to FIG. 6, the clearance 70 is well formed by an outline peripheral edge 72 having a size and shape for forming a spaced joint between the tiles 66. This half-bucket joint configuration serves to provide a blocked line-of-sight between tiles to prevent ash or other debris from entering through gaps 70 during boiler operation. In addition, compressible fibrous mortar (not shown) may be disposed in the gaps or channels 70 between each adjacent tile to further prevent the ingress of ash or other debris. An example of such a suitable compressible fibrous mortar is known as Topcoat 2600 ^™ sold by Unifrax Corporation, Niagara Falls, NY. In the case where the compressible material is used, the clearance 70 is sized in relation to the known compressibility of the particular compressible mortar selected, so that when the individual tiles are placed in the maximum micro-scale bending state of macro-scale bending, Maintains transmission of any force between tiles with a low magnitude sufficient to substantially prevent occurrence. For example, a tile shaped as shown in FIG. 7 having a rectangular face 112 ′ extending substantially 30 cm × 20 cm may have a gap 70 ′ extending at least approximately 6 mm from adjacent tiles. Should have

In the illustrated embodiment, the floating attachment mechanism 68 has a plurality of flexible arms 76 with convex ends 78 adapted to engage recesses 80 of similar size disposed within the tile 66. A rail 74 having Thus, the arm 76 is deflected in a releasable engagement with the tile 66 to facilitate installation and removal of the tile. In addition, the elasticity of the arm 76 may cause the tiles (in other words) to move or "float" with respect to the wall 62 in accordance with the dimensional change of the tile 66 caused by the thermal gradient and the elevated average temperature. 66 to the wall 62. In this regard, the floating attachment mechanism 68 is a tile 66 with at least three degrees of freedom with respect to the wall 62 (ie, along three axes x, y and z orthogonal to each other as shown). ) Can be moved. In addition, along with the movement along the x, y and z axes, the tile may rotate around the tube 18 or may be bent towards or away from the tube 18. The rail 74 comprising the arm 76 and the convex end 78 is preferably made of a flexible corrosion resistant material such as stainless steel.

As shown, the face 112 of the tile 66 may be provided with an outline that substantially matches the outline of the wall 62 to provide a tile with a relatively uniform thickness t .

Referring to Fig. 7, an alternative embodiment of the present invention is shown as a tile device 60 '. This embodiment is substantially similar to the tile device 60 shown in FIG. 6, but uses a floating coupling mechanism 68 'that is different from the substantially planar face 112'. As shown, this fastening device 68 'is similar in many respects to the fastening device 68' of FIG. 6 except for using approximately 50% smaller arms 76 '.

While embodiments of the floating mechanisms 68, 68 'are shown, as described above, the walls of the boiler 62 in a manner that expands and / or bends the tiles micro-scale without substantially producing a macro-bending effect. It should be understood by those skilled in the art that any mounting mechanism capable of securing the tile to the can be used without departing from the spirit and scope of the invention. In this respect, rigid mounting is provided, for example, so long as sufficient clearance is provided between the mounting body and the tiles so that the above-described dimensional change can be made very small without applying excessive force or stress to the mounting body and / or adjacent tiles. The device may be used in place of the flexible arms 76, 76 '.

One example of such an optional device may be inserted into a substantially large sized hole 84 (shown in phantom) disposed in a tile, and may be made of stainless steel or the like extending substantially parallel to the tile face 112. Providing one or more pins 82 (shown in phantom). Pin 82 is secured to wall 62 in any convenient manner (not shown) known to those skilled in the art. In this manner, the tile may be secured to the wall 62 provided with sufficient clearance to effectively "float" the wall as described above.

Referring now to Figures 10 and 11, another embodiment of the present invention is shown as a tile device 60 ". The tile device 60" is substantially the same as the tile devices 60, 60 'of Figures 6 and 7. Although similar to. Another floating coupling mechanism 68 "is used. As shown, this fastening device 68" engages a substantially semi-circular slot or recess 80 "of the tile 66" as shown. Is similar in many respects to the fastening device 68 'of FIG. 7, except that the arm 76 " has a substantially " C " shape.

Referring to FIG. 11, the slots 80 ″ of the tiles 66 ″ are formed with upper slots 81 and lower slots axially extending inward from the upper and lower edges 116, 118 of the tiles 66 ″, respectively. 83. The upper slot 81 is axially from the upper edge 116 greater than the axial distance d2 of the lower slot 83 to facilitate installation of the tile 66 "as will be described later. It extends well by distance d1. As shown, the upper and lower surfaces 116, 118 are at an angle of approximately 30 to 60 degrees at the intersection with the slots 81 and 83 to facilitate the installation of the tiles 66 ", as described below. In the preferred embodiment, the angle α is approximately 45 ° as shown.

Referring now to Figures 12-15, a method of installation of a tile 66 "is shown. Referring to Figure 12, a tile 66" shows the top surface 116 of the tile in substantial axial alignment and By positioning between the lower arms 76 ". This orientation can be achieved by placing a portion of the upper surface 116 in surface-to-surface engagement with the tube 18, as shown. For reference, the surface 116 of the tile 66 "is moved axially upward as indicated by arrow a and the lower surface 118 is directed to the tube 18 as shown by arrow b . Pivot close. This operation slides the upper slot 81 (see FIG. 11) for receiving engagement with a set (ie, top) of the arms 76 "as shown. This movement is shown in FIG. The tile 66 "is moved for substantially parallel alignment with the tube 18 until the tile covers the lower arm 76". The tile is then in the lower slot 83 (see Figure 11). It can be moved axially toward the adjacent pre-installed tile 66 "(ie in the direction of c ) to receptively engage the lower arm 76". This movement is preferably the lower arm 76 ". It continues until it engages with the proximal end 120 of slot 83 (see FIG. 11). At this point, adjacent tiles 66 "are arranged in a direction that is preferably spaced half-thickness sideways as shown in Figure 15 to complete the installation. Then, additional tiles 66" (not shown) are identical Can be installed in a manner.

The examples shown below are intended to illustrate any aspect of the invention. It should be understood that these examples should not be construed as limiting.

Yes

Example 1-compare

A series of conventional bolted tiles of the general type shown in FIGS. 1 and 2 are installed in the furnace in a pattern as shown in FIG. 16. Tiles classified as A, B, C, and D were equipped with linear variable-displacement transducers (LVDTs) to measure the displacement of the tiles away from the tube wall during normal furnace operation. As shown, tiles B and D are positioned in a tile arrangement provided with a conventional flexible mortar (Topcoat 2600 ^™ described above) between adjacent tiles. Referring to FIG. 17, the output of LVDTs indicates that the measurement tiles are simultaneously displaced in close proximity to each other to provide evidence that macro-scale warpage has occurred. (The difference in the magnitude of displacement indicated by the graph is evident due to the deviation in the position of the LVDTs in the tile.) It should be noted that the LVDT 5 located in the tile B is not shown in FIG. 17 because it is a fault. .

Example 2

The array of tiles of the invention is mounted in a test boiler. The tile was constructed and mounted to the boiler in a manner substantially as shown and described above with respect to FIG. 7 using barrier material between the boiler wall and the tile and Topcoat 2600 ^™ between adjacent tiles. Selected tiles, designated A, B, C, D, E and G, were equipped with LVDTs in the manner described in Example 1. As shown in FIG. 17, the output of these LVDTs shows that the tiles were displaced independently from each other in a different manner than that shown in Example 1. FIG. Thus, these test results indicate that the tiles of the present invention accommodated individual (micro-scale) deflections without causing macro-scale deflections.

Attachment mechanisms 68, 68 ′ and 68 ″ may move or “float” tiles 66, 66 ′ and 66 ″ with respect to wall 62, but maximize heat transfer to the tube through tile 66. Those skilled in the art will appreciate that it is desirable for the instruments 68, 68 'and 68 "to keep the tile 66 as close to the surface of the tube 18 as possible.

In addition, the above-described hanging tile and the modified hanging tile device can be used with the present invention. In addition, as discussed above, conventional bolted tile fastening devices provide additional clearance between the stud and the bore, allowing the tile to float against the wall, thereby allowing use of gaps and corrosion barriers between adjacent tiles of the present invention. It can be modified to be.

The above description is originally taken for the purpose of illustration. While the present invention has been shown and described with respect to exemplary embodiments thereof, those skilled in the art will recognize that the foregoing and various other changes, omissions, and additions in form and detail may be made without departing from the spirit and scope of the invention. Will understand.

Claims (31)

In the refractory tile device for use in the wall of the boiler, A plurality of tiles having a floating fastening device capable of joining the walls to keep the tiles in a movable relationship spaced apart from each other, The tile is configured in size and shape to provide a gap between adjacent ones of the tiles, the gap configured to sufficiently accommodate the dimensional change of the tile that appears during exposure to the operating temperature of the boiler, And a corrosion barrier disposed between the tile and the wall. The refractory tile device of claim 1, wherein the fastening device maintains the tile on a wall in a spaced apart and movable relationship. 3. The fire resistant tile apparatus of claim 2, wherein the tile is configured in size and shape to provide a clearance sufficient to accommodate the dimensional change between at least a portion of the tile and the tube wall. 2. The fire resistant tile apparatus of claim 1, wherein the clearance is sufficient to accommodate the dimensional change of the tile due to exposure to average temperature and exposure to temperature gradients experienced during operation of the boiler. The refractory tile device of claim 4, wherein the temperature gradient is in the range of about 200 to 600 ° C. and the average temperature is in the range of about 500 to 1400 ° C. 6. 6. The fireproof tile apparatus of claim 5, wherein the tile is maintained in close contact with the wall of the boiler to maintain the temperature gradient within the range of about 200 to 600 ° C. The refractory tile device of claim 6, wherein at least a portion of the tile remains overlapped with at least a portion of the corrosion barrier, and a portion of the corrosion barrier remains overlapped with at least a portion of the wall. 2. The floating fastening device of claim 1, wherein the floating fastening device includes a tab disposed on one of the wall and the tile, and a receptacle disposed on the other of the wall and the tile, wherein the member and the receptacle connect the tile. And refractory tile arrangements adapted to be mutually spaced with sufficient clearance to maintain said movable relationship. 9. The fireproof tile device of claim 8, wherein the floating fastening device comprises a hanging tile device. 9. The fire resistant tile device of claim 8, wherein the floating fastening device comprises a T-slot tile device. 2. The floating fastening device of claim 1, wherein the floating fastening device includes a tab disposed on one of the wall and the tile, and a receptacle disposed on the other of the wall and the tile, wherein the member and the receptacle connect the tile. And refractory tile arrangements adapted to mutually have elasticity sufficient to maintain said movable relationship. The refractory tile device of claim 1, wherein the receptacle comprises at least one slot, the at least one slot extending in an axial direction. The refractory tile device of claim 12, wherein the at least one slot extends inwardly from an edge of the tile, and the edge is edged relative to an edge of the tile. 14. The apparatus of claim 13, wherein the at least one slot comprises first and second slots extending inwardly from opposite edges of the tile, the first slot being less than a distance from each opposite edge of the second slot. Fireproof tile device extending approximately twice the length. 14. Refractory tile apparatus according to claim 13, wherein the edge machining extends at an angle of approximately 30 to 60 degrees with respect to the transverse direction. The refractory tile device of claim 1, wherein the floating fastening device provides the tile with at least one degree of freedom of movement with respect to a wall. The refractory tile device of claim 16, wherein the floating fastening device provides the tile with at least two degrees of freedom of movement with respect to a wall. 18. The refractory tile device of claim 17, wherein the floating fastening device provides the tile with at least three degrees of freedom of movement relative to a wall. The refractory tile device of claim 1, further comprising a compressible material disposed in the gap. 20. The fire resistant tile apparatus of claim 19, wherein the compressible material prevents foreign matter from passing into the gap. The device of claim 20, wherein the compressible material comprises fibrous mortar. The refractory tile device of claim 1, wherein the barrier compresses the fluid. 23. The refractory tile device of claim 22, wherein the fluid comprises a gas flowing between the tile and the wall. 23. The refractory tile device of claim 22, wherein the fluid comprises a coating applied to the tube wall. 25. The fire resistant tile apparatus of claim 24, wherein the coating is adapted to attach to the wall and the tile is free from attachment. 27. The refractory tile device of claim 25, wherein the coating comprises a membrane. 27. The refractory tile device of claim 26, wherein the coating comprises phosphate attached silicon carbide (SiC). The refractory tile device of claim 1, wherein the tile further comprises a peripheral surface of a size and shape that forms a half-thick peg seam spaced between the adjacent ones of the tiles. 6. The fire resistant tile apparatus of claim 5, wherein the average temperature is in the range of about 750 to 1200 ° C. In the refractory tile device for use in the wall of the boiler, A plurality of tiles disposed on the wall in a movable relationship spaced apart from each other, The tile is of a size and shape that provides a gap between adjacent ones of the tiles, the gap being sufficient to prevent macro-scale bending of the tile while exposed to the operating temperature of the boiler, And a corrosion barrier disposed between the tile and the wall to prevent corrosion. In the method of increasing the useful life of the boiler wall, (a) providing a plurality of tiles having a floating fastening device capable of engaging the wall to keep the tiles in a movable relationship spaced apart from each other; (b) determining the size and shape of the tile to provide a gap between adjacent ones of the tiles, The gap is configured to sufficiently accommodate the dimensional change of the tile that appears during exposure to the operating temperature of the boiler, (c) placing a corrosion barrier on the wall; (d) coupling the floating fastening device to the wall; The tile overlaps the wall and increases the useful life of the boiler wall with the corrosion barrier disposed therebetween.