US 2931211 A
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Description (OCR text may contain errors)
J. D. MCCULLOUGH 2,931,211
STORAGE TANK EXPOSURE PROTECTION COVERING Filed NOV. 18, 1953 FIG.1 I
April 5, 1960 A? INVENTOR 7.9 James lfl/c Cu/lozzy/z STORAGE TANK EXPOSURE PROTECTION (IOVERING Application November 18, 1953, Serial No. 392,791
4 Claims. (Cl. 72-44) This invention relates in general to metal storage tanks or vessels, and more particularly to an exposure protection covering and to a method of applying such a covering.
When tanks are used to store a liquid or gaseous fuel above the ground, for example, they must be protected from the adverse elfects to the metal shell from both exposure to the elements and to an outside fire. A covering to effectively reduce or eliminate the deleterious effects of weather and/or fire on the vessel and its contents should be simple to apply. It should form a hermetic covering capable of withstanding the corrosion, erosion, heat, or similar conditions; without transmitting to, or exposing, the tank metal to such conditions. It should accomplish this without the probability that the outside protective surface itself may wear off.
Accordingly, it is an object of this invention to provide a method of covering storage tanks or similar vessels with a refractory concrete covering which is of simple durable construction and quick to apply and which will completely protect such tanks from exposure.
It is a further object to provide an apparatus for eifectively securing a refractory concrete or similar material to the outside surface of a storage tank which is simple to use and which apparatus may be itself covered for protection from exposure.
In accordance with the present invention, a covering of this type is provided in a novel manner involving the enclosing of cover reinforcing and attaching means within the covering itself, so that such means are protected by the covering from the deleterious effects of weather, or high heat due to combustion.
More specifically, in practicing the method of the present invention, a plurality of metal clips are secured in longitudinally spaced relation along flexible metal bands so that each band has a number of clips projecting therefrom at predetermined points along its length. The bands, with the attached clips, are then tightly wrapped around the pressure vessel shell or any projections or extensions thereof, being tightened in position by suitable means such as a band sealer. The shell is then completely wrapped with a wire screen or mesh secured to the outer ends of the projecting clips, these clips holding the screen in predetermined spaced relation to the outer space of the shell. Following the positioning of the screen, a plastic concrete covering is applied to the shell to a depth sufiicient to cover the screen or mesh, the concrete being anchored in position by the mesh and by the clips, these clips preferably being specially formed to enhance their anchoring efiect on the covering.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating ad vantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which an embodiment of the invention is described and illustrated.
2,931,211 Patented Apr. 5, 1960 Of the drawings:
Fig. l is a plan view, with the covering partly broken away, of a gas tank having a refractory concrete covering in accordance with the invention;
Fig. 2 is an end view of the gas tank shown in Fig. 1;
Fig. 3 is an enlarged detailed sectional elevation of a metal band and clip used to secure the tank covering as shown in Fig. 1;
Fig. 4 is an enlarged end view of the metal band and clip shown in Fig. 3;
Fig. 5 is a top plan'view of the metal band and clip as shown in Fig. 3;
Fig. 6 is an enlarged detailed view of the end of the tank shown in Fig. 1 showing the manner of securing tank covering bands to the supporting saddles;
Fig. 7 is an enlarged and detailed top plan view, partly broken away, of the manhole of the tank shown in Fig. 1; and
Fig. 8 is an enlarged diametric sectional view of the manhole extension shown in Fig. 7 taken on line 8-8 of Fig. 7.
A gas tank and covering means illustrated by Figs. 1 to 8 of the drawings comprises a substantially horizontally disposed cylindrical metal tank shell 10 supported by concrete saddles 11 and 12 adjacent each end. The tank is covered by a coating of kaolin-base refractory concrete 13 of the hydraulic setting type, which may in a particular application, be 1 /2" thick. This concrete is anchored to the tank in a manner described hereinafter.
In accordance with the invention the reinforcing and attaching means for the tank refractory concrete covering comprises the metal bands 16 along which are strung a plurality of the Z-shaped metal clips 15. In the embodiment as shown in Figs. 3, 4 and 5, each Z-shaped clip includes a substantially straightintermediate web portion a having substantially parallelfianges, an inner one b and an outer one 0 projecting in opposite directions from each end of the web portion.
The inner flange b of each clip has serrations or saw cuts upon the inner surface which is adjacent the web portion. The free edge of the inner flange b is bent back so that a U-shaped recess is formed through which the band 16 may pass. A plurality of the Z-shaped clips are normally strung on the bands 16 by passing the band through the bent back U-shaped recess of the inner flange. The clips are arranged along the band at spaced intervals as determined by the cover reinforcing strength desired. In this instance they are spaced approximately one foot apart. The clips are fastened in these spaced positions on the band by squeezing the U-shaped portions of each clip together so that the serrations become embedded in the band.
The web portions of each clip has angular notches d and e cut into each side at horizontally offset positions to provide additional gripping surfaces for the concrete covering which will be applied over them. The outer flange portion 0 has an opening 1 centrally positioned thereon to provide a means for securing wire mesh thereto by stringing wire through the opening and around a reticulated portion of the wire mesh and fastening the ends of the wire together.
The tank shell 10 is covered by first encircling the horizontally extending portion with a plurality of the bands 16 having the Z-shaped clips 15 fastened atfixed positions along the length thereof. The bands are arranged on the shell so that the Z-shaped clips will extend out from each band and from the shell at substantially evenly spaced intervals over the whole shell surface. The bands are normally tightened by using a mechanical tightener and band sealer in which the two ends of the band are brought together and held that way by a seal band 17 which is clamped by pressure around the connecting ends. The bands 16 fit the tank snugly, any slack being taken up by driving steel wedges under them. With the bands in position on the shell the clipsproject out from the tank surface Where they act as anchors for the insulating concrete and provide means for-fastening the wire mesh in ,place.
The wire bands :are attached to'the ends of the drum by anchoring one of the band ends to the concrete saddle 12 as shown in Fig. 6. Each band is attached to the saddle by an angle iron 18, which is placed over the band'lfi and fastened to the saddle by means of a bolt 19. The band is bent back over the angle iron 18 and sealed to an intermediate portion of the same band with a metal sealing band using a mechanical band sealer. The other end of the band 16 is looped over the first girth band on the horizontally disposedcylindricalportion of the band and is also sealed with a metal sealing band As shown by Fig. 2, a vertically arranged band 16 is attached in this manner on each side of the center line of each of the tank ends. Two inclined bands are crossed over each end and also attached to the saddle and the girth band as described.
The covering is applied to the flanged cylindrical manhole extension 20 and its cover plate 22 by positioning the clip-carrying metal bands in the manner shown in Figs. 7 and 8. One metal band having Z-shaped clips '24 attached thereto, is clamped around the vertical cylindrical Wall of the extending portion, the clips 24 having a web portion a of suflicient length so that the outer flange will extend beyond the periphery of a flange portion 26 of the manhole extension. A metal band with smaller clips 28 attached is tightened and fastened around the vertical edge of the cover plate 22. These clips 28 have a web length which will cause them to project out from the cover to the plane of the outer flange of clips 24. Additional bands 30 and 32, with clips attached, are stretched over the top of the cover plate 22 and fastened to the band encircling the cover. No bands or clips are arranged around a circular space 34 which is left open to permit a pipe flange to be inserted. Additional spaces 36 to permit removal of bolts are'also left uncovered on the cover plate top.
After all the bands with the clips attached are in place, wire mesh, preferably of galvanized metal having 2" x 2" .reticulations, is placed completely over the tank shell, including the ends thereof and the manhole cover, and fastened to the outer flanges of the clips by means of a steel wire which is looped through the individual'holes in the outer flanges of the clips and tightly twisted around the wire mesh, whereby the clips hold the mesh spaced from the tank surface. Wire mesh is also similarly applied to the manhole cover top and sides leaving vacant the spaces 34 and 36 for flange and bolt holes. The side mesh is wired at the top ends to the cover mesh but a parting or separating plane 38 is left between the cover plate and the vertical extension of the tank to permit removal of the cover after concrete is applied.
After the mesh is in place and fastened to the clips over the tank shell, concrete is applied to the shell, preferably by spraying it on with a gun designed for that purpose. It is sprayed directly against the tank shell through the mesh and'applied until .a depth ofconcrete forms onthe tank which just covers the wiremesh. Removable templates the size of flange holes and boltholes are placed in the positions corresponding to where bolts and flanges are to be fitted on the cover plate while concrete is applied. The templates are removed when the concrete is dry, thereby leaving the'bolt and flange holes free of concrete.
The concrete mix used should be such as to form a hard refractory concrete having good structural strength when set, e.g. aporous'light-weight refractory concrete mixfor .cement gun application, consisting of a kaolin clay base, and a hydraulic setting cement binder, and capable of withstanding temperatures up to 2000 F. for at least one hour. The concrete is allowed to dry for at least one week under favorable outdoor drying conditions and then a commercial weatherproofing, preferably one containing asbestos fibers, should be applied over the concrete in order to insure against moisture penetrating the concrete and also to increase the insulating properties of the covering.
With the exposure protection covering applied to the tank as describedin'accordance with the invention, none of the metallic parts, including the anchoring devices, are exposed to the outside, and since these anchoring devices remain inside the fireproof concrete where they cannot be burned off, washed off, eroded or corroded, the likelihood of their failure is slight. The covering will remain substantially intact even after a direct application of a water stream from a high pressure fire hose.
The combination of the metal bands and clips with wire mesh attached thereto may be applied to any shaped tankor vessel, by properly placing the bands and securing them with metal band seals.
While in accordance with the provisions of the statutes thebest form of the invention is illustrated and described, those skilled in the art will understand that changes may be made'in the form of the apparatus disclosed Without departing from thespirit of the invention coveredby the claims and that certain features of my invention may sometimes be used to advantage without a corresponding use of other features.
What is claimed is:
1. A storage tank exposure protection coveringcomprising a plurality of thin metal bands girdling said tank and clamped directly to said tank at distributed positions; a plurality of thin clips attached to said bands, said clips 'having an inner portion shaped to be held by said metal bands, a web portion projecting out from said bands and said tank, and an outer portion at the end of said projecting portion; a thin wire mesh sheet encompassing said tank and fastened to the outer portion of said clips; and a refractory insulating concrete covering said tank under and over said wire mesh and having a thickness just greater than the-spacing of the mesh from the tank.
2. A fireproof storage tank comprisingametal cylindrical shell, a plurality of thin metal bands encircling said shell and clamped to said shell at spaced intervals along the shell length and around the ends thereof, a plurality of thin metal clips attached to eachof said bands and projecting out from said shell, at least one wiremesh sheet encircling said shell and fastened to'said clips,.a refractory insulating concrete covering said shell and said wire and having a thickness just greater than the spacing of the mesh from the tank, and a waterproof initially plastic protection coating applied to completely cover the outer surface of said insulating concrete.
3. A fireproof insulated storage tank comprising, .a horizontally elongated metal cylindrical tank shell, means for supporting said shell at each end thereof, a covered cylindrical manhole projection extending fromssaid shell, a plurality of thin metal bands encircling said'shell and clamped directly to said shell at spaced intervals along the shell length, a plurality of thin metal clips attached to each of said bands and projecting out from said shell; at least one similar metal band with clips attached, fastened to said end supports and to oneof said encircling bands; said bands extending overeach end of said drum; at least one similar metal band with clips attachedencircling said manhole projection; at least one Similar band with clips attached fastened at each of their ends to said bands encircling said manhole projection and extending over said manhole cover; a Wire mesh sheet extending over and covering said tank shell, said manhole projection, and said manhole cover, said wire mesh sheet being fastened to said clips and held away from said tank by said clipsyand a refractoryinsulating concrete' covering said shell and said manhole projection and cover and extending under and over said wire mesh and said clips and having a thickness just greater than the spacing of the mesh from the tank.
4. A storage tank exposure protection covering comprising a plurality of thin metal bands girdling said tank and clamped directly to said tank at distributed positions; a plurality of thin clips attached to said bands, said clips having an inner flange portion shaped to be held by said metal hands, a web portion projecting out from said bands and said tank, and an outer portion at the end of said projecting portion; a thin wire mesh sheet encompassing said tank and fastened to the outer portion of said clips, and a refractory insulating concrete covering said tank under and over said wire mesh and having a thickness just greater than the spacing of the mesh from the tank.
References Cited in the file of this patent UNITED STATES PATENTS 553,319
20 Rose Jan. 21, 1896 6 Winslow "Feb. 12, Carroll Apr. 7, Flannery Dec. 15, Hough Feb. 9, McCall Mar. 30, Marguess Oct. 15, Loucks June 19, Leriche July 26, Van Ness May 22, Christensen et al Apr. 27, Rose Feb. 21, Pagct June 9, Henzel June 15, Bondy et al Aug. 15, Hensel Nov.- 27, Pomykala Nov. 28, Loveday May 11, Dalton Nov. 1,
FOREIGN PATENTS France Dec. 19,