US2948432A - Breather reservoir - Google Patents

Description

Aug. 9, 1960 Filed Jan. 14, 1957 R. W. BODLEY TL BREATl-IER RESERVOIR 2 Sheets-Sheet 1 IN VEN T0 S.

Aug. 9, 1960 R. w. BODLEY zm 2,948,432

BREATHER RESERVO IR Filed Jan. 14, 1957 2 Sheets-Sheet 2 /fllllllllmlll' INVENTORS.

' rates BREATHER RESERVOIR Filed Jan. 14, 1957, Ser. No. 634,121

2 Claims. (Cl. 220-85) The invention relates to tanks utilized to store volatile liquids such as gasoline and more particularly to a breather reservoir arrangement associated therewi-th incorporating a movable diaphragm of flexible material arranged to vary the vapor space in the tank.

The invention comprehends an improved arrangement of that type of breather reservoir as illustrated in the patent to Lester A. Wilkin, No. 2,269,568, issued Ianuary 13, 1942. This application is a continuation-inpart of our co-pending application No. 523,471, filed July 21, 1955, and now abandoned. -Extensive experience with the type of breather reservoir and fiexible bag arrangement illustrated in the mentioned patent has shown that that arrangement presents many difficulties in commercial application. It has been found that When the bag contacts the liquid, as for example when sufficient vapor pressure is not present in tank to infiate the bag, that the buoyancy of the bag on the liquid is lost due to the side portions of the bag laying over the dome portion causing it to sink deeply into the liquid and sometimes in an uneven condition. This sinking action could accentuate any tcndency of the bag to leak, thereby shortening its life.

Accordingly, it is a general object to provide a breather arrangement having float and upper limit control means associated therewith. f

It is a further general object of the invention to provide a breather reservoir of the type described having novel balancing control means associated therewith thereby providing improved operation 'as the diaphragm of bag is cycled through its upward and downward movements responsive to a varying vapor pressure within the tank.

It is a particular object of the invention to provide a breather reservoir arrangement of the type described having a centrally located annular rigid member, said member being arranged to provide the impervious diaphragm with fioat control means When the latter is in contact with the tank-contained liquid.

lt is a further specific object of the invention to additionally provide weight control means associated with the rigid member to 'aid in the maintenance of the diaphragm in proper Operating position during all upward and downward movements of the arrangement.

These and other objects of the invention will become apparent in the course of the following description and from an examination of the concerned` drawings, wherein:

Figure l is a schematic sectional view of a storage tank incorporating the novel breather arrangement and illustrating the arrangement in the tank empty condition,

Figure` 2 is a view similar to Figure l and illus-trating the arrangement with the bag floating on the tankcontained product when no vapor pressure is present,

Figure 3 is al view similar to Figure 1 illustrating the bag in fully inflated position under maximum vapor pressure,

Figure 4 is a sectional' view of a tank arrangement,

partly in elevation, and embodying a slightly modified form of the invention,

Figure 5 is a detail view of the central member employed in Figure 4, and

Figure 6 is 'a detail view of a preferred bag connection employcd.

Directing attention to the drawings, it will be seen that the tank may comprise` a steel shell 10 having a liquid supply line 12 communicating therewith. The tank may additionally be provided with a manhole arrangement 14, which accommodates entry into the tank when the latter is empty to provide for inspeotion of the interior portions thereof.

It is well known that the vapor pressure Within a gasoline storage tank increases during the daytme due to' the direct rays of the sun on the tank, which causes a heatng of the vaporl and liquid surface within the tank thus increasing the rate ofevaporation and the intensity of the molecular action of the vapors within the tank. During the night the temperature Vmay drop to such an extent that 'a large portion of the vapors are condensed, thus resulting in a Variation of vapor pressure from night to day over a relatively wide limit.

To accommodate this fiuctuating vapor pressure the tank 10 isprovided with an upwardly extending housing 16, saidv chamber acting .as 'a reservoir to provide increased vapor space within the tank. A flexible diaphragm or bag 18 is peripherally secured to the chamber 16 as at 20, said bag 18 dividing the housing 16 and tank 10 into upper and lower compartments 22 and 24, respectively. It will be noted that the supply line 12 communicates with the compartment 24, thus providing for entrance and exit of volatile liquid to that compartment. The bag 18 is made of a suitable flexible material as will withstand the deteriorating 'action of the volatile liquids or vapors associated therewith. A vent arrangement 23 may be provided at the top of the housing 16 to 'accommodate entrance and exit of air during bag action and to further provide access means to the compartment 22 for inspeotion purposes and the like.

A rigid member 26 is secured to the bag 18, preferably centrally thereof and in spaced relation to the tank 10 and housing 16. This member 26 is preferably a solid circular plate, however, it may be composed of an annular ring having a portion of the bag 18 stretched across the bottom thereof.

In a preferred embodiment of the invention, the member 26 is provided with a plurality of upstanding elements 28, said'elements 28 being joined adjacent their upper ends by an annular element 30, thus providing a fence -arranged peripherally around the member 26.

Directing attention to Figure 2, which illustrates the bag in float-position on the liquid, it will be seen that as the member 26 sinks in the liquid 34, portions of the immediately adj acent bag 18 wrap up and around the upstanding fence-like elements 28 to provide a buoyant pontoon-like arrangement, offering proper support for the bag or diaphragm 18 on the liquid. This pontoon and resulting buoyant effect assures that the bag 18 will fioat evenly on -the liquid, thereby increasing its life. To Eaid this buoyancy feature and particularly to `aid in controlling proper position of the bag, the member 26 has suspended therefrom a` weight 36, which is carried from the member 26 by means of a plurality of flexible members or means 38. The Weight 36 has an additional function in that it aids in balancing the element' 26 and v maintaining the latter in 'a substantially horizontal posiarranged to engage the top of the compartment 22 to limit upward travel of the bag to thereby aid in preventing the bag, during movement thereof, from covering the vent arrangement 23.

Considering the operation of the novel Vbreather arrangement, it will be understood that the tank as shown in Figure l may be considered empty whereby the bag will assume the hanging position illustrated due to the central position of the member 26 and weight 36. As the tank is filled with cool volatile liquid, the bag assumes the floating position shown in Figure 2 under the above-described pontoon action of the central arrangement. As the vapor pressure in the tank increases, usually in response to climatic heating action, the bag slowly expands and rises evenly to the fully expanded'position illustrated in Figure 3. As the vapor in the tank condenses and the pressure decreases, the action is reversed and the bag may evenly return to the position shown in Figure 2. Of course, it will be understood that the action of the bag is responsive to the vapor pressure in the tank, hence the bag may assume any intermediate position between the positions of Figures 2 and 3 as the current pressure may dictate.

In some instances, when the tank 10 is subjected to relatively severe cooling, a vacuum will be produced n the chamber 24. In these instances the bag 18 will take the position and form as illustrated in phantom at 40 in Figure l.

Attention is directed to Figures 4 through 6 which illustrate a slightly modified form of the invention. The bag 18 is again peripherally connected, as at 20, to the chamber 16 as hereinbefore described. A central member 50 comprises a lower pan element 52 consisting of an annular bottom plate or disk 54 having a wall or 'rim 56 peripherally upstanding therefrom. The rim 56 may comprise a plate '58 having an angle 60 (Figure 6) continuously welded to the upper edge thereof, as at 62. The wall 56 and the bottom plate 54 together form a pontoon-like pan which will float on the liquid surface 34 to offer buoyancy to the entire arrangement.

Specifically, considen'ng Figure 5, it Will be seen that a plurality of upstanding members 64, 64 are also secured to the bottom plate 54 and extend above the horizontal angle 60 in a fence-like arrangement. The members 64 may be tack welded to the angle 60. The upper ends of the members 64 are tied together by an annular angle member 68 similar to the earlierdescribed embodiment. Members 70, 70 may be secured to the lower side of the plate 54 to serve as means to connect the flexible lines 38 and the weight 36 to the assembly.

Considering Figure 6 which illustrates the manner of connection of the bag to the central member, it will be seen that the horizontal portion of the member 60 .may be provided with an aperture 72 and the bag 18 may be provided with a peripherally arranged thickened portion 74. A sealing strip 76, preferably of non-metallic material, is interposed between the horizontal portion :of the angle 60 and the portion 74 of the bag 18. Non-metallic washers '78, 78 may also be arranged in the series and an upper clamping bar 80 may be positioned above the portion 74. A carriage bolt S2 and cooperating nut 84 and metallic washer 77 serve to tightly and sealingly secure the entire arrangement to the horizontal portion of the angle 60. It has been found that the arangement described adequately prevents any leakage of product at the connection of the bag and the central member 50.

Returning to Figure 4, it will be seen that this embodiment also employs the central weight 36 and flexible connections 38 of the previous embodiment and for the same purpose. In operation, the pan 52 formed by the plate 54 and the rim 56 provides initial buoyancy for the bag when same is floating on the liquid. In those cases where due to the action of the bag or the like, as heretofore described the pan arrangement iscaused to asa-18,482

tip, the bag again folds upward over the fence-like members 54 to form therewith an additional pontoon to prevent sinking 'of the entire central arrangement. This action, similar to that of the previously described embodiment, afiords enough buoyant effect to prevent the undesired immersion of the bag attachment arrangement in the product. Further, the fence-like arrangement 54 again acts as a stopping member as the bag is brought to the fully inflated position in the chamber 16.

Thus it will be seen that the novel arrangement therein disclosed provides a bag `or diaphragm arrangement, which will function in response to the action of the vapor pressure within the storage tank to variably increase or decrease the vapor space within that tank. The arrangement is further provided with a centrally located float control means which insures proper positioning of the bag when it is in contact with the liquid within the tank. The particular fence-like arrangement of both embodiments additionally functions as a limiting stop to engage an upper portion of the tank and prevent the bag from moving to fully inflated position over the vent. The arrangement is further provided with a balancing weight, which aids in maintaining the formed pontoon in a horizontal position when the bag is in contact with the liquid and further aids in controlling the action of the bag as it is urged to move upwardly and downwardly in response to varying vapor pressure within the tank.

The invention as herein disclosed and illustrated by preferred embodiment is susceptible of various changes which will be apparent to those skilled in the art without departing from the spirit thereof' or the scope of the appended claims.

What is claimed is:

1. A breather reservoir arrangement comprising a closed tank for storing volatile liquid and including a lower portion and an upper portion having a substantially smaller cross section than the lower portion, said upper portion having a closed top, an inflatable flem'ble diaphragm of impervious material secured to the tank for dividing the tank into an upper and lower chamber, said diaphragm being inflatable by vapor pressure developed by the volatile liquid, vent means supported by the center part of said closed top for permitting air to pass into and out of the upper chamber in response to deflation and inflation of said diaphragm, said diaphragm being constructed to extend downwardly away from said vent means when deflated and the liquid level is below a predetermined level and to extend upwardly into engagement With substantially all of the center portion of said closed top adjacent said vent means when infiated by vapor pressure, means secured centrally of said diaphragrn in spaced relation to said tank and including a floor member and a perforate upstanding wall member, said wall member having an upper rim part for coacting with the center part of the closed top adjacent said vent means, said wall member partially engaging said diaphragm when said diaphragm is deflated and in contact with said liquid to provide a buoyant fioat arrangement and said upper rim part coacting with that portion of the center part surrounding said valve means when said diaphragm is inflated to prevent the diaphragrn from obstructing the operation of said vent means.

2. The combination of a tank for storing volatile liquid and including a lower portion and an upper portionv having a substantially smaller cross section than the lower portion, said upper portion having a closed top, an inflatable diaphragm of impervious material located in the tank and secured to the inner tank wall adjacent the juncture of the upper and lower portion, said diaphragm dividing the tank into an upper and lower chamber and being nflatable by vapor pressure developed by the volatile liquid, vent means located in the center portion of said closed top for filling and evacuating the upper chamberin -response to deflation and inflation of said dia-V phragm, means secured centrally of said daphragrn in spaced relation to said tank and including a floor member and a perforate wall means, said perforate wall means including a plurality of spaced rod members extending upwardly from said floor member and terminating in an annular member, said diaphragm being configured to hang downwardly in said lower portion When the liquid is below a predetermined level and to lie substantially adjacent to the inner wall and closed top of said upper portion when inflated by vapor pressure, said wall member when said diaphragm' is deflated and in contact with said liquid coacting with said diaphragm to provide a float and said annular member when said diaphragm is inflated engaging said center portion'of said closed top surrounding said vent means to -prevent the diaphragm from obstructing said vent means.

'References Cited in the file of this patent UNITED STATES PATENTS 2,269,568 Wilkin Ian. 13, 1942 2,378,517 Trautman Inne 19, 1945 2,490,767 Allen Dec. 13, 1949 2,584-,953 Wiggins Feb. 5, 1952 FOREIGN PATENTS 106,097 Australia Dec. 7; 1938 1,076,532 France Apr. 21, 1954

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