US2920850A - Support means for long tanks - Google Patents

Description

Jan. 12, 1960 1.. T. CAMPBELL SUPPORT MEANS FOR LONG TANKS Original Filed Dec. 10, 1948 FIE 1- United StatesPatent 'O SUPPORT MEANS FOR LONG TANKS Louis T. Campbell, Morrisville, Pa., assignor to United States Steel Corporation, a corporation of New Jersey Continuation of abandoned application Serial No. 64,558,

December 10, 1948. This application June 12, 1956, Serial No. 590,912

2 Claims. (Cl. 2481'46) 'This ,invention relates to an improved structure for horizontally supporting long steel tanks and is a continuation of my co-pending application Serial No. 64,558, filed December 10, 1948, and now abandoned.

Long horizontal tanks are used in many processes throughout industry. The tanks are commonly constructed of thin steel plates which are commonly sup ported and strengthened by a series of flanged structural members equally spaced along the length of the tank and extending transversely to it. The transverse members rest upon two or more beams or girders which extend the length of the tank and are supported on masonry or concrete piers. The top flanges of the transverse members are fastened to the bottom of the tank and the bottom flanges to the longitudinal girders, so as to form a rigid structure, of which the tank is a part.

This type of construction is entirely satisfactory where the tank is used at or near room temperature. However, it has placed a limitation on tank length in those instances wherein operations must be conducted at elevated temperatures. For example, in a continuous strip pickling operation the solution temperature is about 210 F. and the length of a tank used in this process will increase as much as 0.01 inch per foot of length as it is heated to operation temperature. To limit damage to the tank and its lining as consequence of thermal expansion (or contraction) it is the present practice to limit the length of individual tanks to about 100 feet and where greater than 100 feet of processing length is needed to use multiple tanks.

The use of multiple tanks is disadvantageous for a number of reasons. Their construction is more costly than that of a single unit of comparable length; they require greater floor space; they present a greater surface area from which heat losses can take place; and they present more places at which spillage can occur, thus increasing solution losses. In the case of corrosive solutions the spillage which occurs between tanks shortens the life of the tanks and increases maintenance costs. Moreover, the expedient of limiting tank length reduces, but does not always avoid damage to the tank. 1 Some buckling of the tank bottom always occurs when expansion is restrained and in pickle tanks which are commonly lined with rubber and brick, this buckling frequently causes damage to the lining which requires costly repairs.

It is accordingly an object of the presentinvention to provide an improved structure for supporting horizontal steel tanks whereby thermal expansion or contraction can take place without damage to the tank or its related arts.

p Another object is to provide an improved support structure whereby longer tanks can be used than was possible heretofore.

It is a further object to provide an improved substructure for horizontally supporting an elongated structure subject to substantial changes in length as the result of conditions attendant its use.

These and other objects will become apparent from the following specification when read in conjunction with the attached drawings, in which:

Figure l is a longitudinal cross section through a pickle tank and the support structure of the present invention; and

Figure 2 is a transverse cross section through the tank and its support structure.

Referring more particularly to the drawings the reference numeral 1 refers to an open top steel tank which may be protected against corrosion by providing its inner surfaces'with a rubber lining 2 which in turn may be protected against abrasion and thermally insulated from the solution by a bonded masonry lining 3. The tank 1 rests upon a series of spaced-apart beams 4 which are placed transverse to the length of the tank. The beams 4 are preferably spaced equally along the length of the tank, and extend substantially the width of the tank but may be extended beyond the tank as required to give satisfactory stability to the completed structure. The top flanges of the beams 4 are rigidly fastened by welding, riveting or bolting to the bottom of the tank. The transverse beams 4 rest upon a sub-base comprised of beams or girders 5 which extend substantially the length of the tank. The girders 5 are supported by piers 6. While only two piers 6 are shown it will be understood that intermediate piers are provided as the needs of the design indicate.

The bottom flange of the center beam 4A of the series of transverse beams 4 is welded or otherwise rigidly fastened to the top flanges of the longitudinal girders 5. This permanently positions the center of the tank with respect to its supporting structure. The remaining transverse beams 4 are not fastened to the girders but merely rest thereon. This allows movement of the ends of the tank in either direction from a fixed center point. Thus when the tank is heated, the resulting expansion can proceed in both directions from a fixed center and is, therefore, substantially unrestrained, the transverse beams being free to creep and/or slide along the longitudinal girders. Conversely, contraction can take place without damage to the tank or its related parts as the tank or its contents cool.

While only the center transverse beam 4A is shown as fastened to the substructure, in actual practice it is preferred to fasten two or three beams on either side of the center beam. This provides greater rigidity to the whole structure and while expansion or contraction would be restrained in the portion so fastened because of the limited length of such portion a total change of length is negligible, consequently damage to the tank cannot occur. We will refer to this structure in the following description and in the claim as a beam, but it will be understood that such designation will include either a single beam or a few beams.

As previously stated the transverse beams 4 are preferably spaced equally along the length of the tank. This is not essential, in fact, for extremely long tanks it may be desirable to decrease the spacing of the beams toward the end portions of the tank. The exact spacing of the transverse beams depends upon many factors in the design of the tank. The beams provide rigidity to the tank bottom and must not be spaced so far apart as to permit sagging of the bottom nor yet so close as to present an almost continuous area of contact with the members of the substructure. The latter condition would interfere with their ability to creep or slide along the upper surfaces of the substructure and would thus defeat the ends of the invention. The beams should be spaced at such distance that the portion of tank between adjacent beams is sufficiently stiif to transmit the horizontally acting forces caused by expansion to and through the transverse 3 beams and thus cause them to move along the substructure. For all cases ordinarily encountered in practice, a space of about three feet, center-to-center, will be satisfactory.

While one embodiment of my invention has been shown and described it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. An improved elongated strip pickling tank having end Walls defining tank width, side walls defining tank length and a horizontally disposed fiat bottom, a series of longitudinally spaced members having fiat top and bottom surfaces disposed with said top surfaces immediately below the tank bottom to extend the width thereof and rigidly secured thereto, and a series of at least two transversely spaced members having fiat top surfaces disposed with said surfaces immediately below the bottom surfaces of said first mentioned series to extend substantially the length or" said tank and rigidly secured to the bottom surface of at least one of said first mentioned series, the bottom surfaces of the remaining members of said first mentioned series on either side of said secured member being unsecured to but resting directly upon said top surfaces of said second mentioned series in movable relation thereto.

2. An elongated tank having end walls defining the tank width, side walls of a length which is several times the length of the end walls defining the tank length and a horizontally disposed substatnially fiat bottom, a series of spaced apart members having a length substantially equal to the tank width and top and bottom flanges separated by a connecting web section, said members being disposed immediately below said bottom of the tank at spaced intervals along the length thereof to extend substantially the width of the bottom with their flanges lying in horizontal planes, the top flanges of said members being rigidly secured to the bottom of the tank; and a series of at least two spaced apart members having a length substantially equal to the length of the tank and substantially fiat support-surfaces disposed immediately below the bottom flanges of the first mentioned series of members to extend substantially the length of the tank with their support-surfaces facing upwardly and lying in a substantially horizontal plane;-the bottom flange of the center member of said first mentioned series of members being rigidly secured to the support-surfaces of the second mentioned series, the bottom flanges of the remaining members of said first series being unattached to and resting directly upon said support surfaces in movable relation thereto.

References Cited in the file of this patent UNITED STATES PATENTS 572,995 Jackson et al Dec. 15, 1896 839,942 Mansfield Jan. 1, 1907 880,243 Rominger Feb. 25, 1908 1,634,084 Ruths June 28, 1927 2,226,713 Folmsbee Dec. 31, 1927

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