BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal sectional view of a tubular insert.
FIG. 2 is a plan view of the body of the tubular insert as it contacts an embedded metal structure.
FIG. 3 is a plan view of the lip of the tubular insert as it contacts and engages the metal structure.
FIG. 4 is a sectional view of a complete refractory system which illustrates the manner in which the tubular insert secures refractory members to a pair of heat-absorptive pipes by bolting the tubular insert directly to the heat-absorptive element.
FIG. 5 is a schematic view of the tubular insert as it engages the metal structure and contacts the heat-absorptive element which is protected by the refractory member.
FIG. 6 is a sectional view of a complete refractory system which illustrates the manner in which the tubular insert secures refractory members to a pair of heat-absorptive pipes by welding the tubular insert directly to the heat-absorptive element.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A tubular insert is shown in FIG. 1. The tubular insert 1 is a tubular member with an outer diameter that is consistent throughout its body 2 and includes two ends. At one end of the tubular insert, hereinafter known as the distal end, the outer diameter increases so as to form a lip, or rib, 3 around the outer circumference of the tubular insert 1. The inner diameter of the tubular insert remains constant from the distal end until the opposite end, hereinafter known as the basal end. At the basal end, the inner diameter narrows, creating a shelf, or inverted lip 4, around the inner circumference of the tubular insert 1. The radial extent of this shelf 4 is such that a flat washer can rest on the area between the inner diameter of the tubular insert body 2 and the inner diameter of the shelf 4. Optionally, this washer is a locking washer. Preferably, the difference between the inner diameter of the tubular insert body 2 and the inner diameter of the shelf 4 is between ¼″ and ½″, and ideally the difference in diameter is 11/32″. However, there remains an opening 5 in the basal end of the tubular insert 1 sufficiently large to allow the necessary angle for a weld rod so that a good structural weld can be obtained between the basal end of the tubular insert 1 and the surface of a heat-absorptive element to be protected. The opening 5 in the basal end of the tubular insert 1 is preferably between ½″ and 1″ in diameter and ideally is 25/32″ in diameter. The tubular insert 1 can be made out of any weldable metal, such as carbon steel, and is preferably constructed of stainless steel pipe, such as 304 stainless. The length of the tubular insert 1 varies depending on the density of the refractory member, with a longer tubular insert being feasible in a less dense, better insulated member. Generally, the tubular insert will be on the order of ½ the thickness of the refractory member, but ¾″ tubular inserts can also be used with 2″ thick refractory shapes.
The tubular insert of the instant invention is to be used with a refractory member similar to that described in U.S. Pat. No. 4,528,672, which is expressly incorporated herein by reference. Specifically, the tubular insert of the current invention is to be used with a refractory member having a reticulated metal structure, optionally defined by a plurality of spirals, embedded within. The metal structure may, for example, be in the form of a chain mesh, similar to a link fence, or in the form of a plurality of chains.
When using the tubular insert 1 to secure the refractory member to the heat-absorption element, the tubular insert 1 is positioned within a passageway 6 through the metal structure 8. The outer diameter of the tubular insert body 2 is specially sized so that it fits securely in this passageway 6 and remains in contact with the metal structure 8 at a plurality of locations 7, as seen in FIG. 2. The lip 3 located at the distal end of the tubular insert 1 has an outer diameter that is larger than the passageway 6 so that the lip 3 engages the metal structure 8, thus preventing the tubular insert from passing completely through the passageway 6, as seen in FIG. 3. As illustrated in FIG. 5, when the tubular insert 1 is forced into contact with the heat-absorptive element 9, the lip 3 may collect and gather the metal structure 8, thus increasing the contacts between the tubular insert 1 and the metal structure 8. This connection between the tubular insert 1 and the metal structure 8 serves both to ensure that the tubular insert 1 remains securely embedded within the refractory member and to dissipate heat from the tubular insert 1 into the refractory member, preventing the rapid deterioration of the tubular insert 1.
A typical application of a bolt to connect the tubular insert to the heat-absorptive element is shown in FIG. 4. Two parallel water cooled metal pipes 10 are connected with a metal web 11. The metal web 11 has a hole in it sufficient in size to allow, for example, a bolt, screw, nail or other connection device to pass through. A refractory member 12a and 12b is positioned on either side of the tandem pipes 10. A tubular insert 1a and 1b is inserted into each of the refractory members 12a and 12b until the basal end comes into contact with the metal web 11. Alternatively, the tubular insert 1a and 1b can be integrated into the refractory member 12a and 12b, such as by a weld, adhesive, or snap-fit arrangement, for example, before the refractory member 12a and 12b is positioned adjacent the heat-absorptive element. The tubular inserts 1a and 1b are positioned so that they are in line with the hole in the web 11 allowing an open channel to exist. In one embodiment, a ⅜″ by 1″ (outer diameter) flat washer 13a and 13b is positioned on the internal washer ledge 4 of each of the tubular inserts 1a and 1b. On the flat washer 13a is placed a ⅜″ locking washer 14 and a ⅜ screw 15 or bolt is inserted through the tubular insert 1a containing the lock washer 14, through the hole in the web 11, and eventually through the other flat washer 13b. A ⅜″ hex nut 16 is tightened onto the screw 15 so that the two tubular inserts 1a and 1b are each secured against the web 11 of the metal pipes 10. Because the tubular insert 1a and 1b is also securely retained within the metal structure 8 of the refractory members 12a and 12b, the refractory members 12a and 12b are securely connected to the metal pipes 10, protecting them from the surrounding environment. Other securing arrangements using the tubular inserts 1a and 1b, in addition to the bolt and nut arrangement, will be appreciated to those skilled in the art. For example, a wing nut or expansion nut could be used in securing the tubular inserts 1a and 1b to the heat-absorptive element.
A typical application of the use of a weld to connect the tubular insert to the heat-absorptive element is shown in FIG. 6. Two parallel water cooled metal pipes 10 are connected with a metal web 11. A refractory member 12a and 12b is positioned on either side of the metal pipes 10 and a tubular insert 1a and 1b is inserted into each of the refractory members 12a and 12b until the tubular insert 1a and 1b comes into contact with the metal web 11. A weld rod is inserted into the opening in the tubular insert 5a and 5b, as will be apparent to those skilled in the art. The basal edge of the tubular insert, which is in contact with the metal web 11, is welded to the surface of the web 11. This weld 17 may go around the inside perimeter of the tubular insert 1a and 1b or it may be a fillet weld or a pair of such welds. Because the tubular insert 1a and 1b is also securely retained within the metal structure 8 of the refractory members 12a and 12b, the refractory members 12a and 12b are securely connected to the metal pipes 10, protecting them from the surrounding environment.
The tubular insert provides many advantages over the prior art. For one, the tubular insert reduces labor and associated costs required to manufacture the refractory member. Additionally, the tubular insert reduces inventory since a single refractory shape can be attached to a heat-absorptive element in several different ways, such as through a bolting or welding process. Other advantages of the invention over the prior art will be apparent to those skilled in the art.
While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. The presently preferred embodiments described herein are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.
Patent Application
20080084908
