Patent Grant
4142284
This invention relates to the construction of large diameter storage tanks. It has particular application to the construction of a plurality of such tanks to be used in the building of a tank farm. It has already been suggested in prior patents to build a large diameter storage tank by feeding a strip of steel to a support assembly for forming the steel into a plurality of helical convolutions that extend upwardly, with the edge portions of adjacent convolutions being secured together, such as by welding or riveting. Examples are given by the following patents: In the building of such large diameter storage tanks it is conventional practice to build each tank at the site upon which the tank is to be located for ultimate use. This requires the moving of the apparatus for constructing the tank from use location to use location when a plurality of tanks are constructed. Such moving of the tank construction apparatus is cumbersome, time consuming, and expensive in terms of personnel and equipment involved. The present invention is directed toward the production of a plurality of large diameter storage tanks. In practicing the invention, the tanks are all constructed at a single building site, and are transported from that site to the various use sites. To accomplish this end, strip material is supplied to a support assembly which is located at a single building site. That support assembly supports the strip for production of a large diameter storage tank structure that includes a plurality of helical convolutions extending upwardly. The edge portions of adjacent convolutions are secured together. The tank structure is severed along substantially a horizontal plane above the support assembly, and the portion of the severed tank structure that is located above the severing plane is transported from the building site to a use site remote therefrom. The severing of the tank structure in one cutting operation completes the bottom of one storage tank and the top of the next tank. Advantageously a top structure for the next tank to be built is joined to the top edge of the severed tank structure immediately following the severing operation. For tank transporting purposes, a lifting collar is advantageously used, removably positioned below the top structure of the storage tank. That lifting collar is coupled to the lifting cable of a crane which is used to transport the completed storage tank from the building site to the use site. In the past, it has been conventional to sever spirally formed pipe into individual pipe sections. The following references are representative of this pipe construction technology:______________________________________U.S. Pat. No. Issue Date Patentee______________________________________1,906,011 April 25, 1933 C. G. Naylor3,183,695 May 18, 1965 F. M. Darner3,432,914 March 18, 1969 G. E. Huck3,677,046 July 18, 1972 H. E. Carroll______________________________________ The Naylor and Huck patents disclose the use of end pieces joined to the ends of individual pipe sections for coupling purposes in joining one section of pipe to another. The Huck patent, which provides for the shearing of the strip that is used to form the pipe (rather than cutting the completing pipe), specifically notes that the shearing of the strip to form one end of the pipe forms the beginning end of the strip for the next winding operation. The technology directed to the production of individual pipe sections is not directly applicable to the building of large diameter storage tanks which are spiralled upwardly. Such storage tanks involve massive structures, and it has never been considered practical to build a storage tank at a location other than where it is to be used. The use of a crane for lifting purposes in the building of tanks is disclosed in the following Patent:______________________________________U.S. Pat. No. Issue Date Patentee______________________________________3,239,927 March 15, 1966 R. F. Hozak______________________________________ In the Hozak patent cylindrical tank sections are successively joined one to the other, and a crane is used to lift the joined-together sections until the final completion of a storage tank. The crane, which is located at a single site, is then pivoted to another construction site. All the machinery used to form another tank is then removed to that new location and an additional storage tank is then built. This process continues until a plurality of storage tanks are built in a ring encircling the pivot point of the crane. The tank fabricating apparatus is thus not located at a single building site, and the use of this apparatus is limited to the building of storage tanks located in a single circular ring. In the present invention any number of storage tanks may be built at a single building site and located at any number of use sites. The present invention is briefly alluded to in co-pending U.S. patent application Ser. No. 656,252 filed Feb. 9, 1976 for Storage Tank Construction Procedures in the name of Myron McFatter and assigned to the assignee of the present application. That McFatter application acknowledges the present invention. The invention will be more completely understood by reference to the following detailed description.
| Number | Name | Date | Kind |
|---|---|---|---|
| 1872810 | Raymond | Aug 1932 | |
| 2751672 | Reed | Jun 1956 | |
| 2831720 | Renfroe | Apr 1958 | |
| 3239927 | Hozak | Mar 1966 | |
| 3263321 | Lombardi | Aug 1966 |
