US2388163A - Storage container for fluids - Google Patents

Description

Oct. 30, 1945.

I w. G. LAIRD STORAGE CONTAINER FOR FLUIDS Filed Dec. 17. 1941 INVENTOR Jaw ATTORNEY Patented Oct. 30, 1945 UNITED} STATES PATENT OFFICE STORAGE CONTAINER FOR FLUIDS Wilbur G. Laird, Pleasantville, N. Y.

7 Application December 17, 1941, Serial No. 423,259 Claims. (01. 220--26) This invention relates to improvements in apparatus for storing or holding fluids, and more particularly to improvements in means for re= straining the tilting and tipping of, the movable covers of liquid storage tanks, gas holders and storage apparatus for other fluids.

Various types of vertically movable covers have been provided for liquid storage tanks and gas holders, and various means have been provided for restraining such covers from tilting or tipping. In the storage of liquids such as petroleum oils in large upright cylindrical tanks the movable cover sometimes referred to as a floating deck or roof, a pontoon roof, or a pan,

has often been sunk in the liquid or rendered inoperable because of the lack of suitable guiding means adapted to prevent tipping and tilting.

Sometimes a cover, floating directly on the liquid 1 in the tank, will be tilted sufliciently by the uneven accumulation of snow, ice or dust on one side, to sink the cover in the tank. Pontoons have been provided for such covers to prevent substantial tilting and consequent sinking, and other means have been proposed to accomplish the same result. 1

Gas-holder covers (sometimes called bells, lifts, piston, etc), are sometimes provided withmeans for restraining any appreciable tilting or tipping. Liquid-sealed bell-type gas holders are usually provided with elevated outside, frames to guide their covers, as well as any intermediate lifts. Liquid storage tanks are sometimes provided with liquid-sealed covers for holding gas or vapor above the liquid, and some means, such as guide frames, have been found necessary to keep the cover from tilting and binding. The vertically movable covers in dry gas holders are always provided with some restraining means to keep them level or to prevent tilting. Such covers are usually provided on top with extensive framethese covers are often considerably smaller than the normal internal tank diameter, because such tanks are neither accurate norsmooth, and are merely provided with a loose marginal, seal which engages the wall of the tank. In the .case

of dry gas holders however the shell is built accurately to size and the movable cover is provided with a marginal gasket-type seal which is substantially gas-tight. Covers which are sealed in liquid, either for liquid storage containers, for gas and liquid containers, or for gas holders or containers, are of course gas-: or vapor-tight inside the seal under normal conditions of use.

Since all of these and similar movable covers for storage containers for fluids must be kept from tilting and tipping, the primary object of the present invention is to provide a new and effective means or mechanism for preventing the tilting, binding, tipping and upsetting of movable covers for storage containers for fluids.

Another object of the invention is to provide a new and efiectiv'e means or mechanism for restraining the tilting of the movable cover of a fluid storage container of the type in which the cover moves up or down in response to the increase or decrease of the, volume of the fluid in the container. I

A further object of the invention is to reduce the cost of constructing storage containers for fluids in which the containers ,are provided with covers which move in response to changes in the volume of the fluid in the container.

A still further object of the invention isto provide a new and improved mechanism for keeping the movable cover of a container for fluids, in its normal position of movement with respect to the walls of the container, while at the same time allowing the cover to move up or down in response to the increase or decrease of the volume of fluid in the container.

According to the invention the apparatus for storing or holding fluids comprises an upright container, a cover for the fluid to be held therein adapted to be supported by the fluid and to be moved up or down in response to increase or dezontal plane, the corresponding connecting-bars of all units; being mounted at the same angle' to the horizontal and for simultaneous concordant motion with the cover, said link units being arranged to act simultaneously and positively in response to the motion of the cover, to

Fig. 2 is a broken horizontalsectional view taken on the line 22 of Fig. 3.

Fig. 3 is a broken vertical sectional view of a container particularly adapted for holding liquids and having a floating deck-type cover, in which another form of the linkmechanism is illustrated.

Fig. 4 is a broken horizontal sectional view taken on the line 4-4 of Fig. 5, showing only a part of the apparatus shown in Fig. 5.

Fig. 5 is a broken vertical sectional View of a container of the dry gas-holder type in which stillanother form of the link restraining mechanism is illustrated.

Fig. 6 is a broken vertical sectional view of a container similar to that illustrated in Fig. 1 taken on the line 6-6 of Fig. 7, in which a further form of the link restraining mechanism is illustrated.

Fig. 7 is a broken front elevational view of the apparatus shown in Fig. 6.

Fig. 8 is a broken horizontal sectional view taken on the line 8-8 of Fig. 7.

From a. consideration of the various figures shown in the drawing it will be apparent that the improved link mechanism, for restraining. the tipping of movable covers used in connection with containers for storing or holding fluids, has general application to various types of containers and covers, as will be pointed out hereinafter.

The storage container illustrated in Fig. l of the drawing is of the general type of cylindrical oil tank provided with a bell-type cover for holding vapors and gases, the bell being sealed in the liquid inthe tank. The tank shell is shown at H] and the bell-cover at l2. .The tank shell is preferably provided with an angle-iron curb I4, an oil inlet and outlet l6 and a gas inlet and outlet l8, the latter extending to a point above the top of the tank as shown. The cover in this instance is provided with a central hood member 2|] which passes over the top of the gas conduit l8 as shown to a horizontal plane, and preferably all set in the same relative position with respect to the cover and container. Under these conditions any movement of the cover l2 up or down from a given position is accomplished without any tilting because the series of links distributed around the cover and container act to hold the cover to movement in the same direction, the same distance at all points. In the particular arrange- 'ment shown'in' Fig. 1, 'thesingle links cause the cover to rotate 'slightly'in' the container as it .moves up or down, because the bearings 28 are fixed. The points corresponding to bearings 28 therefore describe a definite are or motion as the cover l2 moves through the range of movement permitted by the particular container and cover. Landing blocks and crown supports, not shown, are usually provided within the container for the cover to reston when the liquid therein is withdrawn completely or to a definite predetermined extent,

In the arrangement shown in Fig. 1 the movement of the cover may be through a distance which may approximate twice that of the length of the links 24, so that links of great length are not necessary. The links however may be mount- 'ed so that the points 26 are always above, or always below the level of the points 28. The series of links 24 not only keep the cover I 2 from tilting but also maintain it concentric with the container, if both are circular in cross-section. R011- ers 22, therefore, while of use in some cases, are not essential. If the container I0 is of small diameter compared to its height, and the links are arranged to pass between the cover and container, the links 24 may be bowed to the curvature of the container. The joints at 26 and 28 may be of. the ball and socket or universal type or of any other suitable design.

The apparatus illustrated in Fig. .l is particularly adapted for the storage of various petroleum products such as gasoline and crude oil, in which the vapors are trapped under the cover 42 and retained without loss, or discharged through the line 18. The apparatus furthermore may be advantageously used as a so-called breather-type tank to hold both oil and vapor and may receive additional gas or vapor through the line i8, or

- may be used exclusively as a gas holder.

in dash and dot lines in connection with the showing of the bell cover in lowered position in the container. The bell-cover is shownas being provided with the usual rollers 22 around its lower circumference for engaging the wall of the container as the cover moves up and down therein with changes in volume of fluid (liquid, gas or vapor) in the container. The means for preventing the tilting of the cover l2 in this instance consistsof a number of stiff link members 24 (three or more), distributed around the periphery of the cover and container, one end of each linkmember being connected to the cover through a pivot joint or bearing 26, while the other end is connected through a similar bearing 28 with the rim of the container M, as shown. The bearing joints 26 and 28 preferably include suitable brackets which are bolted, welded or otherwise fastened to the cover or container as the case may be.

The links 24, which are preferably made of relatively strong material, are allof the same length, all placed at the same angle with respect The apparatus shown in Figs. 2 and 3 illustrates another form of container 30, particularly adapted for the storage of volatile liquids, which is provided with a floating cover 32 slightly smaller than the internal diameter of the container. In this instance, the cover as illustrated is of the pan-type and is provided with the usual container wall-rollers and with a flexible sealing member 34 such for example as a mat seal, which is fastened to the rim of the cover, as shown, and which bears against and is movable along the wall of the container 30 as the liquid level changes. The seal 34 is not 'a gas-tight seal, but merely serves to reduce evaporation losses and prevent air currents from entering the space between the cover 32 and the wall of the container. The floating cover shown in Figs. 2 and 3 is held in substantially horizontal position, or prevented from tilting because of unequal loading and other conditions met with in practice, by providing a number of radially mounted link units distributed around the periphery of the cover and container, such as the unit shown in front view in Fig. 3. This link unit consists of 'end attached to a bracket at the top of the conconsisting of an upper link having anjenii bear tainer 30 through a bearing 38, and having the other end connected'through an end bearing to a similar link 40, which in turnis connected through a bracketed bearing 44 to the cover 32, as shown. The link unit also includes a third link 46 of thesame length as the links 36 and 40. The

links 40 and 46 are connected at theirmidpoints by means of a bearing pin or other suitable pivot joint, while the upper end of the link 46 is pivoted toone end of a short link 48 by an end bearing joint; The short link 48 which is half the length of-the links 36, 40 and 46 is connected by a pivoted end bearing to the midpoint of link 36.

The lower end of the link 46 is provided with a roller 50 which operates along a horizontal surface of thecover 32 as the cover moves up or down in the container. It will be apparent that as the position of the cover 32 changes in the container with changes in the volume of liquid therein, the link mechanism will extend or retract and roller 50 will move radially along the trated in- Figs. 4 and 5 and will be referred to hereinafter; while the method of connecting opposite link units is shown in Figs. 2 and 3, ii1 which the lower portion of the link 46 of opposite units is attached to a motion conveyor such as a taut endless cable or chain 52 by means of a cable clamp 54, and suitably mounting the cable around sheaves 56 on opposite sides of the cover.

The sheaves 56 are attached to the cover 32 outside of the pivots 44. It will be readily apparentthat since the cable clamps 54, on the two opposite units, are on opposite sides of the endless cable loop, that the rollers 50 for both units must move together, if at all, radially toward or away from the center of the cover, so that these opposite link units must function in unison and therefore prevent any substantial tilting of the cover. The use of two or more pairs of such units, in

accordance with the size of the container, will be sufficient to prevent any substantial tilting of the cover. Furthermore, for the particular container and cover, the relationship of the various links shown in Fig. 3 is such that the pivot point 44 will move vertically with respect to the point 38.

A series of link units as shown in Figs. 2 and 3 may be used on any type of movable cover, such as pontoon roofs, pistons, bells, etc. The bracket for the fixed pivot point 38, may be attached to any stationary element other than the container wall, and the units may be inverted if desired so long as provision is made to guide the roller in a horizontal path.

The container illustrated in Figs. 4 and 5 is of the general type of dry gas holders and may be cylindrical or polygonal as desired. In this instance, the apparatus comprises a bottom plate 60, a side wall or shell 62 of any desired height, and a piston type cover 64 provided with a packing seal 66. Since such an apparatus is used exclusively for holding gas some means is always provided to prevent the tilting of the piston, and in the present instance the improved link unit restraining means is illustrated and used for that purpose.

I In Fig. 5, two of the link units are shown, each ing attachment to a fixed bracket on the rim of thecover at 10,: and an end attachment: with a similar link .12." The link 12 has a hearing attachment at 14 to abracket fixed to the bottom plate 60, anda midpoint-bearing attachment with a third link I6,which in turn has its 'ipper end pivoted to one end ofa half-length link 18. The link Ills also attached by its other end to the midpoint of the link .68 by meansof a bearingpin or similar pivot member; The lower end of link 16 is provided with a roller and the link unit as'a wholefunctionsin substantially the same manner as the link unit shown in Fig. 3, except that movement of the roller 80 is restricted by means of aretaining guide member '82, fastened tothe containerbottom 60. 1 The motion conveying means for securing si multaneous action of all of'thelink units (preferably 3 or more) used in the c ont'ainer of Figs.

4 and 5, comprises an endlesscable E 84 extendiing entirely around inside the container and mounted on sheaves 86 secured tothebottoiii platetfl in the arrangement shownfso that a section of the cable adjacent each link unit is substantially parallel to the plane of the unit (see Fig. 4). The cable i fastened to the lowei end of each link l6' by means of a cable clamp 88 at a time whenth'e cover 64 issubstantially level and all of the linkunitsare extended to the same degree. "After the'clampsq are secured to the cable, all of the link iinits must function at the same time and in the 'same man'- ner, as'thecover 64 moves up or downfls'othai; the pivot points 10 mustiall move through the same distance at the same rate. "In the particu lar showing'in Figs. 4 and 5, "the links68, |2 and 16 are of thesamelength and therefore the pivot point 10 for each unit must move vertically with respect to the point 14. The guideflmember's 82 prevent any other motion. The link units of Figs/4 and 5"may be used on any type of 'covr, in the stored fluid or'outside. F

The storage container shown in Figs. 6, 7 and 8 is similar to thatshown inFig. 1 and comprises a shell 90 and a; deep bell-type cover 92's'ealed in liquid in the container and normally containing vapor or gas above the liquid." The link units illustrated in these figures each include a long link '94 pivoted by its upper end at 96 to a bracket on the cover as shown, and. by its lower end at 98 to a bracket fixed to the inside of an endless movable channel-iron track or bandlflfll A short or half-length link I62 is pivoted by its upper end to the midpoint of the link 94 and'by its lower end at I03 to a'bracket member 104 which is fixed to the upper part of the container shell 90. The endless channel band extends entirely around the container and is heldin substantially the horizontai position shown by means of a plurality of rollers I06 mounted on the brackets l04- (other brackets may be used), the rollers extending into thechannel member. Since there will be from three to twelve of more brackets I 04, and a suitable number of rollers 106, the endless channel band will befree to move on these rollers. All of the links 94 and H12 will be set at the same angle to the horizontal and preferably in the same position with respect 'to the cover and container shell, so that the endless "channel 'band I 00: will serve to connectfall of'the link units, and when cover 92 moves it will cause all of the bearings 98 to moveat the same time and ratejand for the same distance. For exa'mplaif the volume ofwapor is decreased'funderuthe icoverr92,i .th cover will settle. into the liquid in the shell 96 and .all points :96 will be moved vertically .down toward the respective slower pivot points W320i thelinks i62...At the .same time the-channel member Hi6 Willgbfl moved to *therright in Figs. Fii and 8-, so that all points 98 will move i-to ithe right ,to' thesame extent, regard-less of the' fact {that the cover might apply greater s'tresson one unit than on another. Iniact the cover may-be forcing one point 96 down whileron theopposite side of t-he container at another point 96,",the linkv unit theremaybe pulling the cover down, becausejof the band .Hlllconnecting allof the units.-- '1 i The cover'lllin Figs. 6,"7--and- 8 doesnot'rotate in the-container because'ofj thelink I02 and its direct connection at I033. The link H12- nowever is-not essential to :prevent tilting of the coyer, because the band W is always-horizontal, and; the series oilinks 94, in vthe absence of links 1112,; would function the same as the links 24 in Fig. 1-.; Instead of using theband 400, the movement ofkthe pivots 98 can be suitably restricted lay-the use otguides, such as 82 shown in Fig. 5., attached to the-,rim-of the shell 94, if the pivots 98 are provided'with-rollers such as the roller 4m.- The pivot point 98 must be restricted to a horizontal; motionin order toproduc'e a vertical m'otionior the pivot point 96. p

; "If-ra0ks or bandsiofthetype of the band [00 shown; in Figs. 6, 7 and 8 maye be used in other positions to interconnect link units. For examr le-the apparatus shown .in thesefigures might begprovided; with ani upper horizontal band mounted-on rollers like L06, but which, are at,- tached tothe upper rimof the cover 92, theupper ends"of links 194 then being pivoted to the .upper band like theyareat 98 to the band I00. One =ortwo such-bands or their equivalent may be. usedin connection withthe links of Figs. 1, 4 and-5. Where one or twosuch bands or tracks are used with the links-of Fig. 1, the cover may be guided in a vertical path if-desired. In the ease- 0f twoniovable tracks, each link 24 would 7 be. pivoted to each track, and therefore, while thelinks 24would be connected with the container or the "cover, they would not be directly connected.

.Aseries of link unitssuch as used inFig; 1

may be used for covers of the type shown in- Fig. 3, or'onthe usual pontoon-cover or roof. It may be preferablein such cases however to avoid rotationof. the oover,-as for example by using one or two movable horizontal tracks as explained 3.. The "link units may be efiectively. used on liquidssealed, so-called expansion roofs, or covers, with the link units either inside. or outside the cover andcontainer, thus avoiding the use of expensive frames or other expensive arrangements for counterbalancing and stabilizing such covers. Furthermore; the link .-units may be applied to the dififerent lifts ofa'multiple lift-container or gas holder, suchas the well-known liquid-sealed gasholder, and thereby eliminateall of the extensive outside framework; commonly employed to guidethe succession of lifts. All that is necessary. isto provide several link units, such as those illustrated'in-Figs. 1, 5 and 7, between the upper rims-of adjacent lifts and between the upper rim of .thelowermost lift and the stationary part of the holder or some fixed suitable structure. -Instead of connecting-the links with a fixed part of the container .as at 2B in Fig. 1, 38 in Fig.

to a linethroughthe two link units.

enemies 3,:14 inFig; 5, and 103m Fig. 6; =they' may be mounted in pivoted relation to any' fixed object such as a column, pier, abutment, or frame; or to a stable pontoon'ring, or ring of pontoons, floatingon liquid inside the container-"under, inside or below the "cover. Likewise, instead of using cables or chains as described in connection with Figs. 2, 3, 4: and 5, suitableleverage mechanism'or rack. and pinion arrangements or other desired motion conveying elements maybe used .for simultaneously operating the link units ofa given-set in response to any movement of the cover.- The attachments of the link units to the cover or to the relatively stationary-part of the apparatus. need not be direct, and need notbe by a close connecting member. Guided extension rods or-bars may be used; While at least three link units ."are'necessary in order-to completely stabilize aicover or prevent its tiltin where such units are used alone, it is to be understood that two oreven one link unit may be employed" along with other means for-preventing'the tilting of-the container cover. For example, one or more link units may be used along with one or moresets of cables used in the manner described inthe applicants Patents Nos.

coverf rom each other may be used along with a cable orpair of cables mounted at right angles Individual links or a plurality of links may also be employed along with restraining. means other than the cables referred to. Covers of the type shown'in Figs. .1, 6,-7, and 8 may beso heavy asto throw too high a. gas pressurepan'd therefore need counterweighting. This can be accomplished simply inFig. 1, -for example, by using doublelength links with the pivots 28.mounted outside the shell l0 and at aboutthe midpoint of the links, with the lower portions left to swing free. Now if weights are attached to the free ends of the links ,they become levers for counterweighting Counter-weights may be applied to the cover by using levers separate from the links or by any usual mechanism.

The link units shown in Figs- 3 to 8 may includeany suitable number of pairs of long links.

For example, additional links like the pair 40 and 46 in Fig. 3, may be hinged to the-lower ends ofthese links and to each other in the same manner that the pair of links 40 and 46 are hinged together and tothe lower ends of' links '36 and 48.

. It is to be understood that the phrase link unit asused in the appended claims is intended to include any link mechanism adapted-to trans- .mit stress or motion to or from the part of the movable cover with which it; is associated, and that the link units may be connected directly or'indirectly with the cover and container (or a relativelyfixed object). so long as they are influenced positively by the movement of the cover.

Having described the invention and-illustrated the same in connection with certain specific ex.-

series of at least three similar link units spaced with respect to each other and substantially evenly distributed around the container and the outer portion of the cover in the same relation thereto, each of said units including a plurality 'of links interconnected to form a vertically extensible and retractable mechanism, one end of each unit being connected to the cover by a pivot joint at the end of a link, the other end of the unit being connected to a fixed part of the apparatus by a pivot joint at the end of a different link, means interconnecting said units for simultaneous movement in the same direction includ-' ing means connected to the end of a link at the same end of each unit, and means for restricting the movement of said last mentioned link end of each unit to a predetermined plane.

2. In an upright cylindrical type container having a cover movable up and down with the increase and decrease in the volume of fluid held therein, link means for restraining substantial tilting of the cover comprising several interconnected spaced link units substantially evenly distributed around the outer portion of said container and cover, each of said units including a stiff link with a bearing at each end, one of which is attached to the cover and the other end of which is attached to a means for interconnecting said units, each unit including a short link about half the length of said stiff link having one end pivoted to the midpoint of said stifi link and the other end pivoted to the container, said links being mounted in the same angular relation to said container in one direction therearound, and means for confining said interconnecting means to movement in a predetermined substantially horizontal plane.

3. In an upright cylindrical type container having a cover movable up and down with the increase and decrease in the volume of fluid held therein, link means for restraining substantial tilting of the cover comprising several interconnected spaced link units substantially evenly distributed around the outer portion of said container and cover, each of said units including a still link with a bearing at each end, one bearing of all links being connected to the cover at the same level and the other end of each link being attached to a movable means for interconnecting said units, each unit including a short link about half the length of said stiff link having one end pivoted to the midpoint of the stiff link thereof and the other end pivoted to the container, the respective links of each unit being mounted in the same angular relation to said container in one direction therearound, and means for confining said interconnecting means to movement in a predetermined substantially horizontal plane.

4. In an upright cylindrical type container having a cover movable up anddown with the increase and decrease in the volume of fiuid held therein, link means for restraining substantial tilting of the cover comprising several interconnected spaced link units substantially evenly distributed around the outer portion of said container and cover, each of said units including a stiff link with a bearing at each end, one bearing of each link being attached to the cover and the other bearing of which is attached to a movable circular band for interconnecting said units, each unit including a short link about half the length of said stiff link having one end pivoted to the midpoint of said stiff link and the other end pivoted to the container, the respective links being mounted in the same angular relation to said container in one direction therearound, and means for confining said circular band to movement in a predetermined substantially horizontal plane.

5. An apparatus for holding fluids, comprising an upright container provided with a movable cover normally adapted to be moved up or down respectively with corresponding changes in the volume of fluid held in the container, and means for preventing the tilting of the cover during its normal movement in response to changes in the volume of fluid in the container comprising a series of at least three similar link units spaced with respect to each other and substantially evenly distributed around the container and the outer portion of the cover in the same relation thereto, each of said units including a plurality of links interconnected to form a vertically extensible and retractable mechanism, one end of each unit being connected to the cover by a pivot joint at the end of a link, the other end of the unit being connected to a fixed part of the apparatus by a pivot joint at the end of a different link, and movable means interconnecting said units for simultaneous con- WILBUR G. LAJRD.

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