US 2794570 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
T. F. DOWNS June 4, 1957 LINED TANKS 2 Sheets-Sheet 1 Filed Feb. 17, 1955 INVENTOR mama 500W:
ATTORNEY T. F. DOWNS LINED TANKS June 4, 1957 2 Sheets-Sheet 2 Filed Feb. 17, 1955 INVENTOR ATTORNEY United States Patent LINED TANKS Thomas F. Downs, West Chester, Pa. Application February 17, 1955, Serial No. 488,811 3 Claims. (Cl. 220-63) My invention relates to a tank which includes a replaceable liner. Further, my invention relates to a liner assembly which may be used to protect a tank from damage by the fluid held therein.
It is the purpose of my invention to extend the life of fluid-holding tanks by the utilization of a flexible liner which may be easily mounted within a tank and removed and cleaned or disposed of after use for a period of time. It will be appreciated that the various deposits carried by fluids which adhere to tanks may be easily removed and disposed of merely by the removal of my liner assembly.
Another advantage is the ability of my liner assembly to withstand extreme heat and other conditions such as solvent and chemical attack, moisture and exposure to rapidly changing temperatures.
My research has discovered that a film, preferably a polyester film produced from a material which is the reaction product of ethylene glycol and terephthalic acid and which is known to the trade by the Du Pont trademark Mylar, can be utilized for the protection of tanks by mounting the film on a continuous band-like insert which is in turn adjustably aflixed in overlying engagement with the inner face of a flange joint of a tank. By this means of attachment the capacity of the tank may be increased, if desired, and the water-tight integrity of the polyester film and insert liner can be efiiciently maintained over extended periods of use.
Various objects and features of the invention will be fully understood from the following description of a, typical form and application of the invention throughout which descriptive reference is made to the accompanying drawing in which:
Fig. 1 is a front elevational view in section showing the replaceable liner assembly mounted in a spherical tank;
Fig. 2 is a front elevational view of the spherical tank of Fig. 1;
Fig. 3 is a greatly enlarged view in section of a portion of the flange mounting system employed by my instant invention;
Fig. 4 is a perspective view of the replaceable liner assembly; and
Fig. 5 is a top view taken on line 55 of Fig. 2 showing the placement of the afi'ixing means in the flange connection.
Referring now to Fig. 1, it will be seen that the spherical tank comprises an upper hemisphere 15 and a lower hemisphere 16, these being connected at their peripheral flanges 18 and 19 by suitable bolts 14.
Inside the spherical tank is positioned the replaceable liner assembly of the instant invention which includes a continuous band-like insert 20 to which is cemented an upper liner hemisphere 21 of flexible liner material and a lower liner hemisphere 22 of the same material.
As seen in Fig. 3, the spherical tank has been modified by the provision of upper and lower enlarged holes 23 and 28, respectively, which receive the bolts for maintaining the replaceable liner assembly in proper position at the flange joint. The band-like insert 20 is of a dimension sufficient to overlap the flange joint. At the upper edge of the band-like insert 20, suitable lugs, such as nuts 24, are welded to the inner face of the insert 20 to provide threads for the upper insert attaching bolts 25. The lower edge of the insert 20 may be similarly equipped with internally threaded lugs 25 and at least one projecting bolt 27 which may be used for stabilizing the insert 20 during assembly; this projecting bolt 27 facilitates alignment of the lower lugs 25 with the lower tank holes 28 for insertion and attachment of the lower insert attaching bolts 29.
The liner hemispheres are preferably made of a polyester film which is produced from a material which is the reaction product of ethylene glycol and terephthalic acid. This film is known to the trade, as previously mentioned, under the trademark Mylar and it is considered the strongest of all plastic films, exhibiting a tensile strength of one-third that of machine steel and having an operating temperature range from 60 C. to C.
This film is used to produce the hemispherical portions through a vacuum technique which forms the film into the proper shape. The film as shown in Fig. 3 is cemented to the insert, the insert being of suitable material such as brass, steel or plastic.
Preferably upper and lower gaskets 30 and 31 are cemented over the liner hemispheres 21 and 22, respectively, at the upper and lower edges, respectively, of the insert 20 to present cushion-type means which are pressed against the tank hemispheres 15 and 16, respectively, when the replaceable liner assembly is drawn into final assembled position by means of the bolts.
Where it is desired to utilize the replaceable liner and also expand the capacity of the tank, the insert may be designed to enable the spacing apart of the upper and lower tank flanges 34 and 35, respectively, and, to suitably support the weight of the upper tank hemisphere 15, spacers 36 may be positioned between the flanges. The enlarged holes 23 and 28 through which the liner attaching bolts pass compensate for variations in alignment and dimensions.
In large tanks it has been found advisable to employ air vents and in the spherical tank assembly shown it is preferred that an upper vent 37 and a lower vent 38 be used, these vents enabling the exhaust of trapped air between the liner and the tank as the fluid enters the tank and forces the flexible liner into complete conformance with the inner surface of the tank wall.
As seen in Figs. 3, 4 and 5, connections to the tank can be made through the insert, such as the connections 39 and 40 which are shown. The spacers 36, being segmental, enable access to the insert to facilitate the making of the necessary connections.
While the foregoing description and accompanying drawings illustrate a preferred manner of employing my invention, it should be understood that the invention comprehends variations and modifications differing from the disclosed embodiment, without departing from the scope of the invention defined in the appended claims.
1. A replaceable liner assembly for a sectional tank having flanges for coupling the tank wall sections together by a flange joint, said replaceable liner assembly comprising a band-like insert overlapping the inner surface of said flange joint and lying adjacent the peripheral portions of the wall of the tank adjacent said joint, means for adjustably mounting said band-like insert on the tank, and flexible liner sections aflixed to said insert and sandwiched between said band-like insert and the tank wall sections to protect the walls of the tank.
2. A tank in accordance with claim 1 and wherein said l atented June 4, 1957 flexible liner sections are made of a polyester film which is the reaction product of ethylene glycol and terephthalic acid.
3. A tank in accordance with claim 1 and wherein said means for adjustably mounting said band-like insert on the tank are positioned in. a predetermined manner to cause a predetermined separation of the tank flanges and thereby increase the capacity of the tank.
7 References Cited in the file of this patent UNITED STATES PATENTS