US 2304488 A
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Dec. '8, 1942. A. L. TUCKER DISPENSING APPARATU FOR LIQUEFIED GAS Filed March 14. 1941 INVENTOR 4077/03 L. Tl/C'KEQ A'I TORNEY Patented Dec. 8, 1942 umrnn STATES: PATENT OFFICE DISPENSING APPARATUS FOR LIQUEFIED Arthur L. Tucker, Oklahoma City, Okla.
Application March 14, 1941', Serial No. 383,387
Claims. 5, (Cl. 62-1) This invention relates to liquefied gas dispensing systems wherein liquefied hydrocarbon or petroleum gas is'storedin a tank and is delivered through dispensing controls and appurtenances, including a pressure reducing regulator, to a service pipe, for subsequent delivery in vaporized form to vaporized gas using appliances.
The invention has two primary objects, i. e.: to provide a new and more eflicient means of utilizing the heat of the earth to vaporize the liquefied gas within the storage tank when the tank is located underground; and to provide apparatus'which will allow the withdrawal of either liquefied or vaporized gas, or both, during the filling of the tank, yet which will eliminate the danger of any of the liquid gas being drawn off through the vaporized gas service line and subsequently causing a dangerous fire at the point of use.
It is another object of the invention to provide a system of this class which includes a gas reservoir arranged above and in open communication with the storage tank, vaporized g'as being drawn ofi from the upper portion of the reservoir only, to assure delivery of dry gas only at the point of use, the compression of gas in said reservoir, as the level of liquid in the tank rises during filling, serving to prevent the liquid from risingisufiiciently high to reach the vaporized gas outlet, thus greatly reducing the fire hazard attending the accidental passage of liquid gas to the point of use. i
The details in the construction of preferred means for carrying out the invention, together with other objects attending its production, will be better understood from the followingdescription when read in connection with the accompanying drawing, which is chosen for illustrative purposes only, and in which,
Figure 1 is acentral vertical sectional view of apparatus embodying the invention;
Figure 2 is a horizontal sectional View of a dome or riser which is a part of the invention, and is taken along the lined-2 of Figure 1;
Figure 3 is a top plan view of the dome or riser;
Figure 4 is a vertical section taken thru the dome along the line 44, of Figure I;
Figure 5 is a side elevation of one preferred form of heat conducting fin, which is a part of the invention; and
Figure 6 is a similar View of another preferred form of. such a fin, both forms being shown in section in Figure 1.
Referring to. the drawing, an elongated: cylindrical tank, of the type commonly usedfor underground storage of liquids, is designated by the numeral ID. A dome or riser H is welded or otherwise secured in the top wall of the tank, its lower end preferably'terminating at a level approximating the maximum desired liquid level I2 in the tank, and its upper end terminating well above the top of the tank. The top l3 of the dome may be removably secured thereon, as shown, or may be welded, if preferred. As here shown both the top and side walls of the dome are provided with threaded fittings (designated by numerals M to 2'0 inclusive) to facilitate connection of the various controls and appurtenances common to such systems. In addition, the dome is provided internally with a partition 21 which divides the dome intoat least two longitudinally extending passages 22 and 23. In the embodiment shown, a portion of the top edge of this partition is shaped to conform to the nether surface of the top l3, andis rigidly securedthereto, as by welding. The remaining portion of this top edge is cut away as indicated by the numerals 24 and 25 (Figure 4) to allow flexing of the side edges of said partition. As shown clearly in Figure 2, theside edges of the partition are preferably bent to give them a tension contact with the side walls of the dome. Near its upper edge the partition 2! is also provided with perforations 26 to afford restricted communication between the two passages for equalization of gas pressure therein. With the partition mounted in this manner it will be seen that it is removable from the dome along with the top l3, yet when the top is in position on the dome, the partition serves to positively prevent liquid which is being introduced into the tank thru the filler valve 21 and thru the passage 23, from reaching and passing out' thru any gas outlet pipe 28, on the opposite side of the partition. Due to the intercommunication of the two passages 22 and 2'3, the entire dome serves as a gas reservoir thru which dry gas only is drawn off by the gas outlet or service pipe 28, all wet gas settling out of the dome and into the tank proper. Also, the enlarged passage 23, thru which liquefied gas is introduced into the tank creates no resistance to the flow of liquid gas, whereas a relatively small diameter pipe, as is usually employed for filling such tanks, creates a very considerable resistance to the free flow of liquid gas into the tank.
It will be understood that the manner of mounting the partition 2! in the dome H is optional, and if desired the partition may be in the form of a perfectly fiat plate welded along its side edges to the side walls of the dome, and perforated along its top edge. 'Any partition, no matter how it is mounted, will accomplish the same results. The important thing is to locate the gas outlet pipe 28 on one side of the partition (whether it enter the dome thru the side wall or top of the dome) and to locate the filler pipe or inlet for liquid gas on the other side of the partition. It is also important that the lower end of the dome extend for a distance into the interior of the tank so that when the tank is approximately 90% filled with liquefied gas a pressure will be created within the dome sufliciently high tov force the usual pressure regulator 29. closed, or to even force an ordinary pop-off valve 30 to open, notifying the attendant that the tank is sufiiciently full, and thus insuring that approximately of the space in the tank is left for vaporized gas, and at the same time positively preventing the liquid level from reaching the gas outlet pipe.
Coupled with the above described improvements, and forming an important part of the storage and dispensing system, is an entirely new means for increasing the rate and greatly prolonging the time period of the generation of va- :porized gas within the tank. As is well known to those familiar with the art, when such a storage tank is buried underground, the heat of the earth warms the walls of the tank, and wherever the ,liquid actually contacts the tank walls, vaporized gas forms in bubbles which rise thru the liquid. The larger the tank surface area, the faster the generation. This vaporization, or quick expansion, in turn causes frost to form on the exterior wall surface of the tank. This frost sometimes reaches a thickness of six inches, and forms a thick insulation which arrests the conduction of heat from the earth to the liquid in the tank, thus stopping the generation of gas.
To overcome this I provide a plurality of interior fins 3| and 32, which are preferably made of some metal or other material having high heat conducting characteristics. The upper ends of these fins preferably terminatejust below the desired maximum liquid level in the tank, as illustrated in Figure 1, and their side edges are suitably secured, as by welding or soldering to the interior wall surface of the tank. Two preferred types are illustrated. The fins 3| are substantially U-shaped, having a laterally extending portion 33 approximately 8 inches in width, and a flange 34 which extends fiat along the wall of the tank. The other fin 32, is simply a flat plate, as shown. Both are provided with perforations 35 which afford equalization of the liquid level in the tank.
The function of these fins is to receive the heat which is conducted thru the tank wall, and to carry that heat on into the body of the liquid gas. Their presence in the tank greatly increases the warmed surface area in actual contact with the liquid, and thus greatly increases the rate of generation of the gas. I have established by tests, that while frost may form on the exterior of the tank between these fins, they prevent or greatly delay the formation of frost on that portion of the tank wall with Therefore,
which they are in actual contact. after the remaining portion of the tank has ceased to receive heat from the earth, and has thus ceased to generate gas, heat is still transmitted through that portion of the tank wall in contact with the fins. Thus the fins remain In addition,
warm, and the generation of gas along their respective surfaces is prolonged for a very considerable period of time.
Having thus described the invention, and the results it produces, I wish it known that I am aware that the invention may be embodied in other forms which would amount to no more than equivalents of the embodiment disclosed, and I do not wish the scope of this patent limited save by the prior art and by the appended claims.
1. Liquefied gas dispensing apparatus including: a storagetank; a riser or dome having its open lower end in communication with the upper interior of the tank at approximately the desired maximum liquid level therein; a partition dividing said dome into at least two longitudinally extending passages which have restricted communication for equalizing gas pressure therein; and fittings in the dome wall for facilitating communicative connection of gas conducting, gauging, pressure relieving and other controls and appliances common to such systems.
2. Liquefied gas dispensing apparatus includ-' ing: a storage tank; a riser or dome having its open lower end in communication with the upper interior of the tank at approximately the desired maximum liquid level therein; a partition dividing said dome into at least two longitudinally X-' tending passages which have restricted commu nication for equalizing gas pressure therein; fit-' tings in the dome wall for facilitating communicative connection of gas conducting, gauging, pressure relieving and other controls and appliances common to such systems; and laterally disposed heat conducting fins having a portion of their surface in contact with the interior wall surface of the tank proper.
3. Loading and unloading apparatus for a liquefied gas storage tank comprising: a closed topped riser or dome having its open lower end extending through and sealed to the'top wall of the tank and communicating with the interior thereof at a level approximating the maximum desired liquid level in the tank; a partition extending downward from the upper part of said dome dividing at least a portion'of it into at least two, longitudinally extending passages; a filler pipe on one side of said partition affording introduction of liquefied gas into said tank thru one of said passages; and a gas outlet pipe on the other side of said partition for drawing off vaporized gas from said tank thru the other of said passages, the walled passage thru which vaporized gas is drawn off being adapted to prevent any liquid issuing from the filler pipe from reaching the gas outlet pipe, said closed dome adapted to serve as a vapor lock to prevent the liquid'level from rising to a point where liquid gas might be drawn oif thru said gas outlet pipe.
4. A liquefied gas storage and dispensing system comprising: a storage tank; a closed topped dome or riser adapted to serve as a gas reservoir and having its lower end in open communication with the interior of said tank at a point below the top of the tank; a substantially vertical partition dividing said dome into at least two longitudinally extending passages which have restricted communication only affording equalization of pressure therein; a filler pipe affording introduction of liquefied gas into said tank thru one of said passages; and a gas outlet pipe for drawing off vaporized gas from said tank thru the other of said passages, said partition adapted to prevent gas in liquid form, as it flows into said. tank thru said one passage, from reaching and passing out thru said gas outlet pipe, the restricted communication between the two passages permitting the entire dome to serve as a vaporized gas reservoir during the time the tank is not in the process of being filled.
5. Liquefied gas storage and dispensing apparatus comprising: a storage tank; a dome or riser in the top Wall of said tank extending for 10 a distance into the tank proper; a removable top for said dome; a dome partition secured on the nether surface of said top, and adapted to divide the dome into at least two longitudinally extending passages when the top is in position thereon; and fittings in the dome top for facilitating communicative connection of gas handling controls and appurtenances.
ARTHUR L. TUCKER.