The present invention relates to anchors for refractory linings in process equipment and, particularly, to monolithic anchors which allow maximum coverage of substrates to which the refractory material is applied.
Refractory linings have been used for many years in process vessels, reactors, conduits, furnaces and the like, to provide thermal insulation, and in environments such as fluidized catalytic reactors or regenerators or stacks, to provide resistance to abrasion or erosion. Such linings serve not only to thermally insulate a shell or other surface, but also to prolong its service life by shielding it from erosion by abrasion. Common refractories include refractory cement, a concrete cement-aggregate mixture, or a reinforced cement or concrete.
To retain the refractory on the metal surface, various anchoring arrangements have been employed. For example, hexagonal stud grating, and weldable studs have been used. Further, the prior art abounds with various types of anchors as disclosed for example in U.S. Pat. Nos. 4,711,186; 4,753,053; 4,479,337; 4,581,867; 4,680,908; 4,660,343; 4,651,487; and 6,393,789 (789 Patent), all of which are incorporated herein by reference for all purposes. In particular, the 789 Patent discloses a highly useful refractory anchor which has been met with widespread commercial success, but which has certain drawbacks.
For one, the anchor of the 789 Patent is of two piece construction and it is necessary to clip the two pieces together prior to installing the anchor. Further, the anchor of the 789 Patent is fabricated and is relatively labor intensive to make requiring jigs and fixtures to carry out the various fabrication techniques required to form the anchor sections. In addition, the fabricated anchor of the 789 Patent has three feet forming weldable appendages which engage, and are welded to, the metal of the vessel or the like, but which make uniform application of the refractory material in the vessel wall more difficult.
In one aspect, the present invention relates to a refractory anchor which is monolithic.
In a further aspect, the present invention relates to a solid, monolithic refractory anchor which allows maximum, uniform coverage of the refractory material on the substrate to which the anchor is welded.
In yet a further aspect, the present invention relates to a monolithic refractory anchor wherein only a single weld is required to attach the refractory anchor to the metal substrate.
These and further features and advantages of the present invention will become apparent from the following detailed description, wherein reference is made to the figures in the accompanying drawings.
The terms “upwardly,” “downwardly,” “top,” “bottom,” and similar terms of orientation as used herein are with reference to the anchor as it is depicted in
The refractory anchor of the present invention is a solid, monolithic structure which can be made by any number of casting techniques used in forming metal parts such as, for example, lost-wax casting (investment casting), plaster mold casting, sand casting, etc. Methods of casting metal parts are well known to those skilled in the art and need not be described in detail here. The cast or monolithic anchors of the present invention can be made from a variety of metals which can be attached by welding or similar techniques to a metal substrate, e.g. the walls of a reaction vessel. Preferably, however, the anchors of the present invention are cast from stainless steel, e.g., 304 stainless steel.
Referring then to
There is a second V-shaped end portion shown generally as 30 which extends from second end 16 of bridge portion 12. Second end portion 30, has third and fourth wing portions 32 and 34, respectively, which converge at a vertice portion 35 and which have laterally extending tabs 36 and 38, respectively, as well as apertures 40 and 42, respectively.
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In addition to the advantages noted above regarding the single weld to connect the anchors to the substrate, the ability to uniformly apply any suitable refractory over the surface S of a metal substrate 80, the angle of the tabs on the wings as discussed above providing upwardly and downwardly facing surfaces which can serve to resist radially inwardly directed forces caused by the heating of the refractory as well as radially outwardly directed forces which could be encountered when the vessel or the like to which the refractory is attached is under high pressure.
Further, the monolithic structure of the anchor avoids the manual labor required to clip the two pieces of the anchor disclosed in the 789 Patent together, and further minimizes labor by requiring only a single weld for each anchor to be attached to the surface S of a metal substrate 80 forming the wall of a metal vessel.
It has been found that an anchor 10 having certain physical characteristics is ideally suited for repair as well as new refractory construction. In this regard, anchor 10 wherein the bridge 12 is about 2″ long and has a height of from about 0.5″ to about 1.5″ is preferred. In this regard, and when viewed in side elevation as shown in
Further preferred dimensions include the outermost tips of the wings on both sides of the bridge 12 being spaced apart about 3.5″. The apertures in the bridge portion 12 can be any shape but in particular can be rectangular having a dimension of from about 0.125″ to about 0.25″.
As noted above, the angles between the wings and the bridge portion are generally about 127° but can vary in a range of 100° to 140°. Lastly, the diameter of the pedestal 60 above the bottommost section is about 0.5″.
It will be recognized that the above dimensions, angles, and other physical parameters, while being one preferred form of the anchor of the present invention can vary provided that the refractory holding formations, such as the apertures, tabs, etc, are sized/formed to result in maximum adherence of refractory material to the anchor.
Although specific embodiments of the invention have been described herein in some detail, this has been done solely for the purposes of explaining the various aspects of the invention, and is not intended to limit the scope of the invention as defined in the claims which follow. Those skilled in the art will understand that the embodiment shown and described is exemplary, and various other substitutions, alterations and modifications, including but not limited to those design alternatives specifically discussed herein, may be made in the practice of the invention without departing from its scope.
Number | Name | Date | Kind |
---|---|---|---|
4479337 | Crowley | Oct 1984 | A |
4581867 | Crowley | Apr 1986 | A |
4651487 | Nishikawa | Mar 1987 | A |
4660343 | Raycher et al. | Apr 1987 | A |
4680908 | Crowley | Jul 1987 | A |
4711186 | Chen et al. | Dec 1987 | A |
4753053 | Heard | Jun 1988 | A |
D375892 | Kraemer, Jr. | Nov 1996 | S |
D393588 | Tuthill | Apr 1998 | S |
6393789 | Lanclos | May 2002 | B1 |
9861949 | Simon | Jan 2018 | B2 |
10352619 | Yoder | Jul 2019 | B2 |
10508861 | D'Oracio De Almeida | Dec 2019 | B1 |
20180345401 | Giaramita | Dec 2018 | A1 |