CA2057921A1 - Floating roof of synthetic material for liquid storage tank - Google Patents
Floating roof of synthetic material for liquid storage tankInfo
- Publication number
- CA2057921A1 CA2057921A1 CA002057921A CA2057921A CA2057921A1 CA 2057921 A1 CA2057921 A1 CA 2057921A1 CA 002057921 A CA002057921 A CA 002057921A CA 2057921 A CA2057921 A CA 2057921A CA 2057921 A1 CA2057921 A1 CA 2057921A1
- Authority
- CA
- Canada
- Prior art keywords
- roof structure
- tank
- roof
- sandwich
- sandwich module
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D88/00—Large containers
- B65D88/34—Large containers having floating covers, e.g. floating roofs or blankets
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
ABSTRACT
The improvement relates to a method for the installation of a floating roof structure in a closed liquid storage tank and also it relates to the tank roof structure obtained thereby.
It is the purpose of the invention to compose out of a great number of interconnectable syntheitic modules or synthetic sandwich boards 3 backed up by a large number of prefabricated low frame profiles 4, an integral floating roof structure 1 of extremely lightweight construction. Furthermore it is particularly important as a feature that this floating roof structure 1, by its own rigidity and its overall strongness, can fully operate itself as a building site because of the fact that the traverse frame profiles 4 used for strengthening the roof surface structure by interconnecting sandwich modules 3 have a height of e.g. no more than 2 times the single height of a module, i.e. no more than 15 cm. The level of liquid in the storage tank is now covered to a high degree, and apparently it is now possible to suppress even the recent tolerable rate of vaporization enormously, thereby contributing much to the desired degree of environmental purity.
(Fig. 1)
The improvement relates to a method for the installation of a floating roof structure in a closed liquid storage tank and also it relates to the tank roof structure obtained thereby.
It is the purpose of the invention to compose out of a great number of interconnectable syntheitic modules or synthetic sandwich boards 3 backed up by a large number of prefabricated low frame profiles 4, an integral floating roof structure 1 of extremely lightweight construction. Furthermore it is particularly important as a feature that this floating roof structure 1, by its own rigidity and its overall strongness, can fully operate itself as a building site because of the fact that the traverse frame profiles 4 used for strengthening the roof surface structure by interconnecting sandwich modules 3 have a height of e.g. no more than 2 times the single height of a module, i.e. no more than 15 cm. The level of liquid in the storage tank is now covered to a high degree, and apparently it is now possible to suppress even the recent tolerable rate of vaporization enormously, thereby contributing much to the desired degree of environmental purity.
(Fig. 1)
Description
" , T37 960/IA 1 24April 1991 FLOATING ROOF OF SYNTHETI C MATERIAL FOR STOR~GE TAN~
The lnventlon relates to a method for the installation of a floating roof structure in a closed liguid storage tank and further lt relate~ to a floatlng roof obtained thereby.
In vlew to steadlly increaseing requirements in environmental legl81atlon for the storage of volatile liquid products it becomeq a tendency to avold the creation of a level of liquid underneath the floating roof as such creation could give rise to ~ubstantlonal envlronmental problems.
8torage tanks for liquld products may have a diameter from e.g. 8 to nearly 88 meters and in the latter case enormous volume of liquld vapour must be dlscharged to the open alr.
Thls encounters extenslve envlronmental problems because mostly 8uch stored volatlle llqulds dangerously affect the breathlng of human being8 and animals.
Metal floatlng roof structures are known whlch may sink down as a result of llquld movements and/or leakage, resultlng agaln ln the creatlon of a level of liquid. Also there do exl8t floatlng roofs whlch are underneath covered wlth an alumlnlum foll yet glvlng rlse to locally created levels of llquld, causlng the aforementloned dlsadvantages. Moreover a floatlng tank roof structure must be sufflciently strong to be usable as a bullding site for carrying out repair activities.
~ , Accordlng to the invention a floating roof structure, also serving as a bullding floor may be installed in a closed storage tank for liquid, which roof is composed of a number of lnterconnected synthetlc modules thereby carrylng out the following steps:
- , . : . . , .: . , . ;, , , -2~579~
, T37 960/IA 2 24April 1991 : . .
a. a great number of fully enclosed sandwich module board elements of reinforced synthetic material, provided with a core of hard foam and also being locally provided with insert pieces of screwable material, are lengthwise so positioned that they constitute altogether an uninterrupted flat working floor surface, whlch by providing of corresponding roundings for the tank wall, will correspond in its shape and its size wlth the floating roof to be installed, whereas thls working floor l~ supported, at least for a substantial part, by a temporary and premounted flat horizontally positioned roof support scaffolding structure which is located underneath and at a certaln distance from the tank bottom;
b. at the upper side of the working floor and in a direction whlch ls perpendlcular to the longltudinal axis of sandwich module boards there are posltloned a number of oblong transverse frame proflles which are fixedly connected to the qandwlch module boards by means of fasteners thereby provlding - ~.
for a stlff lntegral roof structure;
c. thereafter the roof structure is provided with operatlonal means ~uch as: ., ;' l. a manhole ln order to carry out actlvlties underneath the .:.
roof structure;
ll. at choice a number of roof structure supporting legs, whlch may or may not be ad~ustable;
lll. a number of cable bushings for the use of antl- .
rotatloncables to prevent an undeslrable rotation of the roof structure; .:.
lv. at cholce a number of dralnages for condense llguid; ,; .
v. at cholce a number of air inlet and air discharge means; :
whereafter the horizontal roof support scaffolding structure .
l~ dlsmounted and taken out of the tank allowing the floating roof structure to rest upon its own supporting legs or to rest ~:
upon a number of fixed supporting legs which were installed ;
before on the bottom of the tank; :;~
.
T37 960/IA 3 24April 1991 d. the longltudinal and traverse seams between adjacent modules of the working floor for the roof structure are sealed off at the bottom side of the roof structure by means of self-adhesive tape thereby formlng a totally flat surface, whereafter for the prevention of gas and air inclusions, the seam sllt ls further filled up with synthetic material of the 6kln materlal of the sandwlch module, the self adhesive tape bel~g removed or not after hardening;
e. the flexlble tank wall seal ls thereafter mounted to the clrcumferentlal edge of the roof structure. In a preferred embodlment of the lnventlon the floating roof structure ls bullt up of sandwlch module boards and traverse frame proflles, characterlzed ln that a traverse frame proflle has a polygonal vertlcal cross sectlon and ls composed by two pre~erably rectangular tubular proflles, one on top of the oth~r, partlcularly a lower sguare tubular profile and on top o~ it an upper rectangular tubular proflle,-restlng upon lts ~hort rectangular slde.
It 1~ effective to bulld up the tank roof structure accordlng to stlll another embodiment of the lnvention with a number of cut-off proflle~ each time having a length of at least two time~ the wldth of a sandwich module is applied for, in such a way that every time the utmost ends of the lowermost square tubular profiles and also the utmost ends of the upper rightangled tubular profiles are always located in the central portion of the sandwich module. It appears that for easy handling the length of a cut-off profile preferably amounts 1,000 mm whereas the total integral cross section of the traverse frame profile amounts to 50 x 50 and 50 x 30 square mm respectively.
Thereby the stiffness of the built up tank roof structure may be efficiently obtained while uslng a standard sandwich module having a width of 500 mm, a length of 6,000 mm and a thickness of 50 mm.
.
, .
T37 960/IA 4 24April 1991 In order that a sandwich module possesses sufficient rigidity it may be provlde in a direction perpendicular to its longltudlnal axis with integral insert pieces of screwable materlal at regular distances preferably made of hard ~crewable polylamlnated wood (Multlplex), which pieces are lncorporated ln the foamed core material for the fixlng of screws and suchllke flxlng elements in and to the sandwlch module.
Accordlng to the lnventlon at lts bottom side, the tank roof ~tructùre 15 entlrely flat except for the presence of a requlred manhole flange and varlous bushings (for cables, alr lnlets, alr outlets, supportlng legs) respectlvely 50 that lt ::
i8 vlrtually lmposslble that spaces are created having a level of ll~uld. At the one hand the floating tank roof structure i5 llght enough to float upon the level of liquid whereas at the oth~r hand lt ls pertlnently unslnkable, thls embodlment of lt~ structure constltutes such a rlgldlty that no llquld volume~ are collected upon the tank roof and thus no '::.
unallowable vaporlzatlon wlll occur. By uslng a great number of ad~u~table support legs provlded for underneath the flo~tlng tanX roof structure, the entlre roof structure ls equally ~upported on varlous locations wlth respect to the bottom of the storage tank and all provlsions are avallable to make the operatlonal use of the tank roof structure profltable, thereby excludlng any dlsadvantages whlch ;. :;:
lnherently affect exlstlng floating tank roof structures. ::
According to another embodiment of the invention there are provided alr lnlet and air discharge means for a tank roof structure conslsting of a potshaped housing, having a number of parts, provided with at least one fixing flange for connecting it with the opening in a sandwich module and a cup .
shaped cover of the housing being provided with a number of air inlet and discharge openings respectively which are :` :
covered by a flexible non-return valve, a vertically movable bar being centrally positioned in the cover, which bar is , .
,;
20~7~21 T37 960/IA 5 24April 1991 provlded at its upper end above the cover with an eyelet for eonnection to a cable and within the housinq under the cover and perpendicular thereto said bar is provided with a number of elosed discs, each having an outer circumferential downwardly directed cupshaped edge, whereas the inner side of sald housing is provided with a number of corresponding downwardly dlrected funnel-shaped concentric baffles, in such a way that vapors passing through said means are forced to eseape via this labyrinth seal.
Also aeeording to the invention there is provided for in a ~ermanent fixation by means of a magnet keeping the floating roo~ ~trueture in plaee by means of anti- of the tank by means of anti-rotation eables eharaeterized in that a flat magnet is ~rovided having horizontally and eentrally respectively in at least two mutually perpendieular directions a number of anti-tlltlng elements, one and the other sueh a way that a possible tlltlng polnt or tllting line with respeet to said is located substantlally far away and outwardly from the utmost borderllne of the elreumferential edge of the permanent magnet whlch hold~ to the bottom of the storage tank.
The lnventlon wlll now be further deseribed wlth reference to the accompanylng drawlng of an embodlment shown at dlfferent scale dlmenslons.
Plg. 1 ls a sehematie upper view of a floating tank roof strueture aeeording to the invention;
" .
Fig. 2 shows sehematlcally and in cross seetion the loeation of the tank roof structure which is supported upon the bottom of the tank by means of a great number of support legs;
Fig. 3 shows separately a synthetie module as part of the flat surface of the tank roof;
" :
, :"
T37 960/IA 6 24April 1991 Plg, 4 is partially a cross section through a preferred embodiment of the tank roof structure taken at the sealing off agalnst the wall of the tank;
Fig. 5 also shows a partial cross section of another preferred embodiment of a tank roof structure as shown in Fig. 4;
Flg, 6 i~ a cross section of the traverse frame profiles which are applled for to render the reguired stiffness and strongness to the tank roof structure;
Fig. 7 show~ a special anchoring structure to fix the position of the floating tank roof; ; ~
' '~:'. .
Flg. 8 l~ a cros~ sectlon of a bushing in the tank roof in use for a dipstlck gauglng tube and for anti-rotation cables;
Plg. 9 ls a eross section of a sampling deviee provided for in the tank roof, provided with a star-shaped flexible non-return valve;
Flg. 10 ls a llguid vapour-overpressure drain valve provide wlth a labyrlnth seal avoiding liquid to arrive upon the tank roof;
Flg. 11 is a eross seetion of the manhole structure for the tank roof.
Aeeordlng to the invention the method basically eonsists in the eomposition of an entire floating tank roof 1, shown in ; ;
Fig. 1 and 2, which has a flat synthetic board covering 2 having floating properties. The strongness and the stiffness of the synthetic covering 2 is obtained by interconnecting a great number of sandwich modules 3 to form a flat surface while using traverse frame profiles 4, each of which is constituted by a number of tubular, preferably rectangular ;, I , ~0~7~21 ,................................................................. . ..
T37 960/IA 7 24April 1991 profiles 5, which are traversally coupled to the sandwich modules 3 ln a special manner.
Prlor to bulldlng up a floatlng tank roof 1 at the inside of a storage tank 6 there is erected upon the bottom 7 of the tank, at a workable level of e.g. 80 cm, a scaffolding having a flat upper surface ~not shown here) upon which the sandwich modules 3 are posltloned. After completion of the tank roof structure thl~ scaffolding must be dismounted and finally be carried away through the manhole 8. Upon this flat supporting surface all sandwich module~ 3 are now horizontally positioned according to Pig. 1 and nearby the wall 9 of the tank the sandwlch modules 3 are adapted to the rounded shape.
Internally these sandwlch modules 3, see Fig. 3, are provided wlth a foamed core material 10 whlch i8 composed from e.g. a flat core of hard foam sandwiched between two glass fiber relnforced outer ~kins 11. It is obvious that the sandwich module 3 is entirely unsusceptible for affection by the llguld stored in the tank 6; this being important in the event of mechanical damage to the tank roof structure. The thlckness o~ the sandwlch module 3 ls e.g. 50 mm whereas the outside ~lmenslon of a single, preferably rightangled, ln the drawing shown sguare proflle 5, embodiment amounts to 50 x 50 mm.
Plgs. 4 and 5 ~how the arrangement of the traverse frame profiles 4 in a direction perpendicular to the longitudinal -axis of the oblong sandwich module 3. One tubular profile 5 which has a rectangular cross section, having an overall length of e.g. 100 cm, i8 bondwise placed upon a flrst lower row of tubular proflles 5, see Fig. 6, and it is effective to let the longitudinal seam 12 between ad~acent sandwich modules 3 coincide with a~ abutting seam 12' between the square profiles 5. It is advantageous for obtaining a greater reslstance against bending to compose a traverse frame profile 4 from a lower square tubular profile on top of which in an upright position, a narrower rightangled tubular profile is positioned. The traverse frame profile is a reversed T-profile ;
composition; dimensions 50 x 50 mm and 50 x 30 mm ~', :' "', :,, '':
2~57~21 ~
T37 960/IA 8 24April 1991 respectively. At the one hand installation takes place with short standard lengths, at the other hand it simplifies a qulck mountlng and disassembly respectively. In the hard foam core material of a sandwich module 3 and upon regular ;
distances there is integrally incorporated an insert piece 13 of hard screwable material such as polylaminated wood (Multiplex), which will stand the fixation of fixing elements, llke screws 14.
After all preparations have been made and the tank roof `-~tructure has been completed, all longitudinal and traverse seams 12 between ad~acent sandwich modules 3 must be sealed off again~t liquid. To that purpose the seams 12 are now at the bottom sid~ of the tank roof structure entlrely sealed off wlth ~elf- adhesive tape and than these seams are filled up from the top slde with the same materlal of which the skin coverlng 11 is made. After hardening out there is created an integral roof which fulfllls all required properties with respect to lts own floating power. The self-adhesive tape may be removed after hardening out of the fllled out seam, however thls ls not always necessary.
After the tank roof structure has been completed, the sealing 15 must be lnstalled its construction belng here descrlbed in a global way only. In Fig. 4 an endless seallng llp 16 is llquid tlght connected by means of a collar 17 to the edge of the tank roof 1 and the position of the tank roof 1 is defined also by a spring element 18 the one end 19 of whlch is connected to a seal llp 16 whereas the other end 20 is flxed, through a spring loop 21, to the tank roof 1. Fig. 5 shows another wall seal in cross sectlonal vlew, consisting of a flexlble bumper 16' whlch ls flxed to the tank roof 1 by means of a dlstance holdlng devlce 18'. Flg. 7 shows a bushlng 22 in the sandwich module 3 for an anchorlng cable 23. The upper end of this anchoring cable 23 is fixed to the fixed roof of the storage tank 6 and its lower end 24 is connected to the upper side of a permanent magnet 26 by means of a spring 25. It is 2~7921 T37 960/IA 9 24April 1991 the purpose to anchor the magnet 26 to the bottom 7 of the tank, the presence of a number of anti-rotation cables 23 thereby holding the position of the floating tank roof 1. The magnet 26 is provided with protrusions 27 e.g. from strip materlal whlch is fixed to the body of the magnet 26 by means of clamping or the like thus bringing the tilting point far away from the permanent magnetic surface, thereby guaranteeing the permanent location of the magnet 26 with respect to the bottom 7 of the tank. The extra advantage of this facility, which 18 unbreakably connected to the tank roof structure, is the total avoidance of socalled hot spotwelding to the bottom 7 of the tank.
In Flg. 8 another bushlng 28 ls shown for a fixed gauging tube ~not shown here). A flexible collar or cup 29 is clamped between a flxed flange 30 whlch ls bolted by means of bolts 14' around an openlng ln the tank roof 1 and a removable flange 31 so that the tank roof 1 can move in an upward and downward directlon wlth respect to the flxed gauglng tube. If necessary, the whole tank roof 1 may be sunk for half of lts thlckness lnto the llquid wlthout affecting its effectiveness.
Por taking liquid samples from the storage tank there ls provlded a sampling devlce, Plg. 9, consisting of a funnel-shaped mouth 33 for receiving and centering a bottle shaped container (not shown) whlch is lowered by means of a star-shaped cut flexible valve 34 to sample liquid from the tank content. The annular protruding edge 35 at the lower side of the funnel-shaped mouth 33 rests upon and is guided respectively in u tubular passage 36, provided with a flange 37 and a counter flange 38 for its attachment to the opening in the tank roof 1. At the level of the flange 37 there are ; ;
provided in the tubular widened portion a number of air openings. The valve 34 is attached to the throat of the funnel-shaped mouth 33 by means of a hinge 39 and can be ~
opened by means of a cable 40. The other cable end is ;
connected to a hook 41 which is ad~ustably in its height ""., ~,...
2~7921 ;
T37 960/IA 10 24April 1991 attached to the tank roof 1. The valve 34 is automatically opened ln the event that the lower end of the hook 41 (not fully shown) is running up against a stop, e.g. the bottom 1 of the tank.
If as a result of weather conditions e.g. liquid vapour is colleeted under the tank roof 1 which must be discharged, there are a number of dischargers 32 provided upon openings in the tank roof 1, see Fig. 10. A discharger 32 consists of a pot- shaped housing 42 whlch is downwardly attached to a tubular passage 45 provlded with attachment flanges 43 and 44 res~eetlvely and connected to the tank roof 1. The passage 45 ~ ;
has alr openlngs 46 and lt dlverges downwardly to a funnel 47.
The hou~lng 42 18 eovered by a cup-shaped lid 48 whieh is ~rovlded with passage ways 49 which are closable by means of a flexlble non-return valve 50. A eentral rod 51 havlng an eyelet 53 can be operated by a eable 23' from the upper slde and 80 be llfted or elosed. Attached to the rod 51 and to the houslng 42 are eoo~eratlng labyrlnth baffles and dlscs 54 and 55 respeetlvely which obstruct the escape of vapour. To enable a ~ast escape however the lld 48 i8 operated by means of the cable 23'. ;
, Plg. 11 shows detalls of a manhole. The manhole cover 56 rests upon a tubular collar flange 57 circumferential edge of the manhole 8. The flange is attached by means of screws 14' screwed ln the hard polylaminated (Multiplex) material wlthln the sandwleh module 3. In the eentral portion upon the manhole eover 56 there is a passage opening in which a discharger 32, see Flg. 2, ean be installed and further handgrips are ;
~rovided at the upper and bottom side respectively of the manhole eover 56.
~ , .
Flg. 2 sehematically shows the adjustable support legs 60 whieh are guided by and attached to the tank roof 1 by means of tubular guidings 61. At choice such support legs may have a j fixed length and are attached to the tank roof 1 by means of a -~;. , 20~792~
T37 960/IA 11 24April 1991 tubular guiding 61 or the support legs 60 and their guidings 61 are provided of adjustable locking devices, known per se.
The floating tank roof 1 is of very light construction and it has a hlgh floatlng power and, by its enormous own rigidity resulting from the use of sandwich modules and low traverse frame profiles, ls also an ldeal building floor for carrying out malntenance activities. The smooth surface underneath it prevents all existing disadvantages with known tank roofs.
Con~idering the very small height of the tank roof 1, e.g. 50 mm of the ~andwich module plus two times 50 mm for the composlng tubular profiles 5 of the traverse frame profile 4, lts total helght ls no more than 15 cm (1) at the location of the~e traverse frame profiles 4.
In Plg. 1 the ~lmple and systematlc building up of the tank roof structure by the new method is made visible. The modular arrangement makes lt posslble to make tank roofs of different dlmenslons having the same favorable floating power. The use of the sandwich structure having a hard outer skin make no longer a problem of possible damages and thelr quick repalr.
Slnce the constructlon ls reallzed with simply operable sandwlch modules and whereas the tubular proflles are easlly handled durlng mountlng and demountlng because of the small ~ ;
length, thls novel method offers great advantage~ and extra safety for the envlronment, now that even for very great tanks only a mlnlmum evaporatlon will occur and so it remains controllable. Apart therefrom this floating roof together with lts synthetlc sandwlch modules has a specific heat insulating function for the liquid which is stored in the tank.
' "
,~",',','',, :. "~' " ' ..,; . , ,,~ "
. '~
The lnventlon relates to a method for the installation of a floating roof structure in a closed liguid storage tank and further lt relate~ to a floatlng roof obtained thereby.
In vlew to steadlly increaseing requirements in environmental legl81atlon for the storage of volatile liquid products it becomeq a tendency to avold the creation of a level of liquid underneath the floating roof as such creation could give rise to ~ubstantlonal envlronmental problems.
8torage tanks for liquld products may have a diameter from e.g. 8 to nearly 88 meters and in the latter case enormous volume of liquld vapour must be dlscharged to the open alr.
Thls encounters extenslve envlronmental problems because mostly 8uch stored volatlle llqulds dangerously affect the breathlng of human being8 and animals.
Metal floatlng roof structures are known whlch may sink down as a result of llquld movements and/or leakage, resultlng agaln ln the creatlon of a level of liquid. Also there do exl8t floatlng roofs whlch are underneath covered wlth an alumlnlum foll yet glvlng rlse to locally created levels of llquld, causlng the aforementloned dlsadvantages. Moreover a floatlng tank roof structure must be sufflciently strong to be usable as a bullding site for carrying out repair activities.
~ , Accordlng to the invention a floating roof structure, also serving as a bullding floor may be installed in a closed storage tank for liquid, which roof is composed of a number of lnterconnected synthetlc modules thereby carrylng out the following steps:
- , . : . . , .: . , . ;, , , -2~579~
, T37 960/IA 2 24April 1991 : . .
a. a great number of fully enclosed sandwich module board elements of reinforced synthetic material, provided with a core of hard foam and also being locally provided with insert pieces of screwable material, are lengthwise so positioned that they constitute altogether an uninterrupted flat working floor surface, whlch by providing of corresponding roundings for the tank wall, will correspond in its shape and its size wlth the floating roof to be installed, whereas thls working floor l~ supported, at least for a substantial part, by a temporary and premounted flat horizontally positioned roof support scaffolding structure which is located underneath and at a certaln distance from the tank bottom;
b. at the upper side of the working floor and in a direction whlch ls perpendlcular to the longltudinal axis of sandwich module boards there are posltloned a number of oblong transverse frame proflles which are fixedly connected to the qandwlch module boards by means of fasteners thereby provlding - ~.
for a stlff lntegral roof structure;
c. thereafter the roof structure is provided with operatlonal means ~uch as: ., ;' l. a manhole ln order to carry out actlvlties underneath the .:.
roof structure;
ll. at choice a number of roof structure supporting legs, whlch may or may not be ad~ustable;
lll. a number of cable bushings for the use of antl- .
rotatloncables to prevent an undeslrable rotation of the roof structure; .:.
lv. at cholce a number of dralnages for condense llguid; ,; .
v. at cholce a number of air inlet and air discharge means; :
whereafter the horizontal roof support scaffolding structure .
l~ dlsmounted and taken out of the tank allowing the floating roof structure to rest upon its own supporting legs or to rest ~:
upon a number of fixed supporting legs which were installed ;
before on the bottom of the tank; :;~
.
T37 960/IA 3 24April 1991 d. the longltudinal and traverse seams between adjacent modules of the working floor for the roof structure are sealed off at the bottom side of the roof structure by means of self-adhesive tape thereby formlng a totally flat surface, whereafter for the prevention of gas and air inclusions, the seam sllt ls further filled up with synthetic material of the 6kln materlal of the sandwlch module, the self adhesive tape bel~g removed or not after hardening;
e. the flexlble tank wall seal ls thereafter mounted to the clrcumferentlal edge of the roof structure. In a preferred embodlment of the lnventlon the floating roof structure ls bullt up of sandwlch module boards and traverse frame proflles, characterlzed ln that a traverse frame proflle has a polygonal vertlcal cross sectlon and ls composed by two pre~erably rectangular tubular proflles, one on top of the oth~r, partlcularly a lower sguare tubular profile and on top o~ it an upper rectangular tubular proflle,-restlng upon lts ~hort rectangular slde.
It 1~ effective to bulld up the tank roof structure accordlng to stlll another embodiment of the lnvention with a number of cut-off proflle~ each time having a length of at least two time~ the wldth of a sandwich module is applied for, in such a way that every time the utmost ends of the lowermost square tubular profiles and also the utmost ends of the upper rightangled tubular profiles are always located in the central portion of the sandwich module. It appears that for easy handling the length of a cut-off profile preferably amounts 1,000 mm whereas the total integral cross section of the traverse frame profile amounts to 50 x 50 and 50 x 30 square mm respectively.
Thereby the stiffness of the built up tank roof structure may be efficiently obtained while uslng a standard sandwich module having a width of 500 mm, a length of 6,000 mm and a thickness of 50 mm.
.
, .
T37 960/IA 4 24April 1991 In order that a sandwich module possesses sufficient rigidity it may be provlde in a direction perpendicular to its longltudlnal axis with integral insert pieces of screwable materlal at regular distances preferably made of hard ~crewable polylamlnated wood (Multlplex), which pieces are lncorporated ln the foamed core material for the fixlng of screws and suchllke flxlng elements in and to the sandwlch module.
Accordlng to the lnventlon at lts bottom side, the tank roof ~tructùre 15 entlrely flat except for the presence of a requlred manhole flange and varlous bushings (for cables, alr lnlets, alr outlets, supportlng legs) respectlvely 50 that lt ::
i8 vlrtually lmposslble that spaces are created having a level of ll~uld. At the one hand the floating tank roof structure i5 llght enough to float upon the level of liquid whereas at the oth~r hand lt ls pertlnently unslnkable, thls embodlment of lt~ structure constltutes such a rlgldlty that no llquld volume~ are collected upon the tank roof and thus no '::.
unallowable vaporlzatlon wlll occur. By uslng a great number of ad~u~table support legs provlded for underneath the flo~tlng tanX roof structure, the entlre roof structure ls equally ~upported on varlous locations wlth respect to the bottom of the storage tank and all provlsions are avallable to make the operatlonal use of the tank roof structure profltable, thereby excludlng any dlsadvantages whlch ;. :;:
lnherently affect exlstlng floating tank roof structures. ::
According to another embodiment of the invention there are provided alr lnlet and air discharge means for a tank roof structure conslsting of a potshaped housing, having a number of parts, provided with at least one fixing flange for connecting it with the opening in a sandwich module and a cup .
shaped cover of the housing being provided with a number of air inlet and discharge openings respectively which are :` :
covered by a flexible non-return valve, a vertically movable bar being centrally positioned in the cover, which bar is , .
,;
20~7~21 T37 960/IA 5 24April 1991 provlded at its upper end above the cover with an eyelet for eonnection to a cable and within the housinq under the cover and perpendicular thereto said bar is provided with a number of elosed discs, each having an outer circumferential downwardly directed cupshaped edge, whereas the inner side of sald housing is provided with a number of corresponding downwardly dlrected funnel-shaped concentric baffles, in such a way that vapors passing through said means are forced to eseape via this labyrinth seal.
Also aeeording to the invention there is provided for in a ~ermanent fixation by means of a magnet keeping the floating roo~ ~trueture in plaee by means of anti- of the tank by means of anti-rotation eables eharaeterized in that a flat magnet is ~rovided having horizontally and eentrally respectively in at least two mutually perpendieular directions a number of anti-tlltlng elements, one and the other sueh a way that a possible tlltlng polnt or tllting line with respeet to said is located substantlally far away and outwardly from the utmost borderllne of the elreumferential edge of the permanent magnet whlch hold~ to the bottom of the storage tank.
The lnventlon wlll now be further deseribed wlth reference to the accompanylng drawlng of an embodlment shown at dlfferent scale dlmenslons.
Plg. 1 ls a sehematie upper view of a floating tank roof strueture aeeording to the invention;
" .
Fig. 2 shows sehematlcally and in cross seetion the loeation of the tank roof structure which is supported upon the bottom of the tank by means of a great number of support legs;
Fig. 3 shows separately a synthetie module as part of the flat surface of the tank roof;
" :
, :"
T37 960/IA 6 24April 1991 Plg, 4 is partially a cross section through a preferred embodiment of the tank roof structure taken at the sealing off agalnst the wall of the tank;
Fig. 5 also shows a partial cross section of another preferred embodiment of a tank roof structure as shown in Fig. 4;
Flg, 6 i~ a cross section of the traverse frame profiles which are applled for to render the reguired stiffness and strongness to the tank roof structure;
Fig. 7 show~ a special anchoring structure to fix the position of the floating tank roof; ; ~
' '~:'. .
Flg. 8 l~ a cros~ sectlon of a bushing in the tank roof in use for a dipstlck gauglng tube and for anti-rotation cables;
Plg. 9 ls a eross section of a sampling deviee provided for in the tank roof, provided with a star-shaped flexible non-return valve;
Flg. 10 ls a llguid vapour-overpressure drain valve provide wlth a labyrlnth seal avoiding liquid to arrive upon the tank roof;
Flg. 11 is a eross seetion of the manhole structure for the tank roof.
Aeeordlng to the invention the method basically eonsists in the eomposition of an entire floating tank roof 1, shown in ; ;
Fig. 1 and 2, which has a flat synthetic board covering 2 having floating properties. The strongness and the stiffness of the synthetic covering 2 is obtained by interconnecting a great number of sandwich modules 3 to form a flat surface while using traverse frame profiles 4, each of which is constituted by a number of tubular, preferably rectangular ;, I , ~0~7~21 ,................................................................. . ..
T37 960/IA 7 24April 1991 profiles 5, which are traversally coupled to the sandwich modules 3 ln a special manner.
Prlor to bulldlng up a floatlng tank roof 1 at the inside of a storage tank 6 there is erected upon the bottom 7 of the tank, at a workable level of e.g. 80 cm, a scaffolding having a flat upper surface ~not shown here) upon which the sandwich modules 3 are posltloned. After completion of the tank roof structure thl~ scaffolding must be dismounted and finally be carried away through the manhole 8. Upon this flat supporting surface all sandwich module~ 3 are now horizontally positioned according to Pig. 1 and nearby the wall 9 of the tank the sandwlch modules 3 are adapted to the rounded shape.
Internally these sandwlch modules 3, see Fig. 3, are provided wlth a foamed core material 10 whlch i8 composed from e.g. a flat core of hard foam sandwiched between two glass fiber relnforced outer ~kins 11. It is obvious that the sandwich module 3 is entirely unsusceptible for affection by the llguld stored in the tank 6; this being important in the event of mechanical damage to the tank roof structure. The thlckness o~ the sandwlch module 3 ls e.g. 50 mm whereas the outside ~lmenslon of a single, preferably rightangled, ln the drawing shown sguare proflle 5, embodiment amounts to 50 x 50 mm.
Plgs. 4 and 5 ~how the arrangement of the traverse frame profiles 4 in a direction perpendicular to the longitudinal -axis of the oblong sandwich module 3. One tubular profile 5 which has a rectangular cross section, having an overall length of e.g. 100 cm, i8 bondwise placed upon a flrst lower row of tubular proflles 5, see Fig. 6, and it is effective to let the longitudinal seam 12 between ad~acent sandwich modules 3 coincide with a~ abutting seam 12' between the square profiles 5. It is advantageous for obtaining a greater reslstance against bending to compose a traverse frame profile 4 from a lower square tubular profile on top of which in an upright position, a narrower rightangled tubular profile is positioned. The traverse frame profile is a reversed T-profile ;
composition; dimensions 50 x 50 mm and 50 x 30 mm ~', :' "', :,, '':
2~57~21 ~
T37 960/IA 8 24April 1991 respectively. At the one hand installation takes place with short standard lengths, at the other hand it simplifies a qulck mountlng and disassembly respectively. In the hard foam core material of a sandwich module 3 and upon regular ;
distances there is integrally incorporated an insert piece 13 of hard screwable material such as polylaminated wood (Multiplex), which will stand the fixation of fixing elements, llke screws 14.
After all preparations have been made and the tank roof `-~tructure has been completed, all longitudinal and traverse seams 12 between ad~acent sandwich modules 3 must be sealed off again~t liquid. To that purpose the seams 12 are now at the bottom sid~ of the tank roof structure entlrely sealed off wlth ~elf- adhesive tape and than these seams are filled up from the top slde with the same materlal of which the skin coverlng 11 is made. After hardening out there is created an integral roof which fulfllls all required properties with respect to lts own floating power. The self-adhesive tape may be removed after hardening out of the fllled out seam, however thls ls not always necessary.
After the tank roof structure has been completed, the sealing 15 must be lnstalled its construction belng here descrlbed in a global way only. In Fig. 4 an endless seallng llp 16 is llquid tlght connected by means of a collar 17 to the edge of the tank roof 1 and the position of the tank roof 1 is defined also by a spring element 18 the one end 19 of whlch is connected to a seal llp 16 whereas the other end 20 is flxed, through a spring loop 21, to the tank roof 1. Fig. 5 shows another wall seal in cross sectlonal vlew, consisting of a flexlble bumper 16' whlch ls flxed to the tank roof 1 by means of a dlstance holdlng devlce 18'. Flg. 7 shows a bushlng 22 in the sandwich module 3 for an anchorlng cable 23. The upper end of this anchoring cable 23 is fixed to the fixed roof of the storage tank 6 and its lower end 24 is connected to the upper side of a permanent magnet 26 by means of a spring 25. It is 2~7921 T37 960/IA 9 24April 1991 the purpose to anchor the magnet 26 to the bottom 7 of the tank, the presence of a number of anti-rotation cables 23 thereby holding the position of the floating tank roof 1. The magnet 26 is provided with protrusions 27 e.g. from strip materlal whlch is fixed to the body of the magnet 26 by means of clamping or the like thus bringing the tilting point far away from the permanent magnetic surface, thereby guaranteeing the permanent location of the magnet 26 with respect to the bottom 7 of the tank. The extra advantage of this facility, which 18 unbreakably connected to the tank roof structure, is the total avoidance of socalled hot spotwelding to the bottom 7 of the tank.
In Flg. 8 another bushlng 28 ls shown for a fixed gauging tube ~not shown here). A flexible collar or cup 29 is clamped between a flxed flange 30 whlch ls bolted by means of bolts 14' around an openlng ln the tank roof 1 and a removable flange 31 so that the tank roof 1 can move in an upward and downward directlon wlth respect to the flxed gauglng tube. If necessary, the whole tank roof 1 may be sunk for half of lts thlckness lnto the llquid wlthout affecting its effectiveness.
Por taking liquid samples from the storage tank there ls provlded a sampling devlce, Plg. 9, consisting of a funnel-shaped mouth 33 for receiving and centering a bottle shaped container (not shown) whlch is lowered by means of a star-shaped cut flexible valve 34 to sample liquid from the tank content. The annular protruding edge 35 at the lower side of the funnel-shaped mouth 33 rests upon and is guided respectively in u tubular passage 36, provided with a flange 37 and a counter flange 38 for its attachment to the opening in the tank roof 1. At the level of the flange 37 there are ; ;
provided in the tubular widened portion a number of air openings. The valve 34 is attached to the throat of the funnel-shaped mouth 33 by means of a hinge 39 and can be ~
opened by means of a cable 40. The other cable end is ;
connected to a hook 41 which is ad~ustably in its height ""., ~,...
2~7921 ;
T37 960/IA 10 24April 1991 attached to the tank roof 1. The valve 34 is automatically opened ln the event that the lower end of the hook 41 (not fully shown) is running up against a stop, e.g. the bottom 1 of the tank.
If as a result of weather conditions e.g. liquid vapour is colleeted under the tank roof 1 which must be discharged, there are a number of dischargers 32 provided upon openings in the tank roof 1, see Fig. 10. A discharger 32 consists of a pot- shaped housing 42 whlch is downwardly attached to a tubular passage 45 provlded with attachment flanges 43 and 44 res~eetlvely and connected to the tank roof 1. The passage 45 ~ ;
has alr openlngs 46 and lt dlverges downwardly to a funnel 47.
The hou~lng 42 18 eovered by a cup-shaped lid 48 whieh is ~rovlded with passage ways 49 which are closable by means of a flexlble non-return valve 50. A eentral rod 51 havlng an eyelet 53 can be operated by a eable 23' from the upper slde and 80 be llfted or elosed. Attached to the rod 51 and to the houslng 42 are eoo~eratlng labyrlnth baffles and dlscs 54 and 55 respeetlvely which obstruct the escape of vapour. To enable a ~ast escape however the lld 48 i8 operated by means of the cable 23'. ;
, Plg. 11 shows detalls of a manhole. The manhole cover 56 rests upon a tubular collar flange 57 circumferential edge of the manhole 8. The flange is attached by means of screws 14' screwed ln the hard polylaminated (Multiplex) material wlthln the sandwleh module 3. In the eentral portion upon the manhole eover 56 there is a passage opening in which a discharger 32, see Flg. 2, ean be installed and further handgrips are ;
~rovided at the upper and bottom side respectively of the manhole eover 56.
~ , .
Flg. 2 sehematically shows the adjustable support legs 60 whieh are guided by and attached to the tank roof 1 by means of tubular guidings 61. At choice such support legs may have a j fixed length and are attached to the tank roof 1 by means of a -~;. , 20~792~
T37 960/IA 11 24April 1991 tubular guiding 61 or the support legs 60 and their guidings 61 are provided of adjustable locking devices, known per se.
The floating tank roof 1 is of very light construction and it has a hlgh floatlng power and, by its enormous own rigidity resulting from the use of sandwich modules and low traverse frame profiles, ls also an ldeal building floor for carrying out malntenance activities. The smooth surface underneath it prevents all existing disadvantages with known tank roofs.
Con~idering the very small height of the tank roof 1, e.g. 50 mm of the ~andwich module plus two times 50 mm for the composlng tubular profiles 5 of the traverse frame profile 4, lts total helght ls no more than 15 cm (1) at the location of the~e traverse frame profiles 4.
In Plg. 1 the ~lmple and systematlc building up of the tank roof structure by the new method is made visible. The modular arrangement makes lt posslble to make tank roofs of different dlmenslons having the same favorable floating power. The use of the sandwich structure having a hard outer skin make no longer a problem of possible damages and thelr quick repalr.
Slnce the constructlon ls reallzed with simply operable sandwlch modules and whereas the tubular proflles are easlly handled durlng mountlng and demountlng because of the small ~ ;
length, thls novel method offers great advantage~ and extra safety for the envlronment, now that even for very great tanks only a mlnlmum evaporatlon will occur and so it remains controllable. Apart therefrom this floating roof together with lts synthetlc sandwlch modules has a specific heat insulating function for the liquid which is stored in the tank.
' "
,~",',','',, :. "~' " ' ..,; . , ,,~ "
. '~
Claims (10)
1. Method for the installation of a floating roof structure in a closed storage tank for liquid, which roof is composed of a number of interconnected synthetic modules thereby carrying out the following steps:
a. a great number of fully enclosed sandwich module board elements of reinforced synthetic material, provided with a core of hard foam and also being locally provided with insert pieces of screwable material, are lengthwise so positioned that they constitute altogether an uninterrupted flat working floor surface, which by providing of corresponding roundings for the tank wall, will correspond in its shape and its size with the floating roof to be installed, whereas this working floor is supported, at least for a substantial part, by a temporary and premounted flat horizontally positioned roof support scaffolding structure which is located underneath and at a certain distance from the tank bottom;
b. at the upper side of the working floor and in a direction which is perpendicular to the longitudinal axis of sandwich module boards there are positioned a number of oblong transverse frame profiles which are fixedlya) Roof connected to the sandwich module boards by means of fasteners thereby providing for a stiff integral roof structure;
c. thereafter the roof structure is provided with operational means such as i. a manhole in order to carry out activities underneath the roof structure;
ii. at choice a number of roof structure supporting legs, which may or may not be adjustable;
iii. a number of cable bushings for the use of anti-rotation cables to prevent an undesirable rotation of the roof structure;
iv. at choice a number of drainages for condense liquid;
v. at choice a number of air inlet and air discharge means;
whereafter the horizontal roof support scaffolding structure is dismounted and taken out of the tank allowing the floating roof structure to rest upon its supporting legs or to rest upon a number of fixed supporting legs which installed before on the bottom of the tank;
d. the longitudinal and traverse seams between adjacent modules of the working floor for the roof structure are sealed off at the bottom side of the roof structure by means of self-adhesive tape thereby forming a totally flat surface, whereafter for the prevention of gas and air inclusions, the seam slit is further filled up with synthetic material of the skin material of the sandwich module, the self adhesive tape being removed or not after hardening;
e. the flexible tank wall seal is thereafter mounted to the circumferential edge of the roof structure.
a. a great number of fully enclosed sandwich module board elements of reinforced synthetic material, provided with a core of hard foam and also being locally provided with insert pieces of screwable material, are lengthwise so positioned that they constitute altogether an uninterrupted flat working floor surface, which by providing of corresponding roundings for the tank wall, will correspond in its shape and its size with the floating roof to be installed, whereas this working floor is supported, at least for a substantial part, by a temporary and premounted flat horizontally positioned roof support scaffolding structure which is located underneath and at a certain distance from the tank bottom;
b. at the upper side of the working floor and in a direction which is perpendicular to the longitudinal axis of sandwich module boards there are positioned a number of oblong transverse frame profiles which are fixedlya) Roof connected to the sandwich module boards by means of fasteners thereby providing for a stiff integral roof structure;
c. thereafter the roof structure is provided with operational means such as i. a manhole in order to carry out activities underneath the roof structure;
ii. at choice a number of roof structure supporting legs, which may or may not be adjustable;
iii. a number of cable bushings for the use of anti-rotation cables to prevent an undesirable rotation of the roof structure;
iv. at choice a number of drainages for condense liquid;
v. at choice a number of air inlet and air discharge means;
whereafter the horizontal roof support scaffolding structure is dismounted and taken out of the tank allowing the floating roof structure to rest upon its supporting legs or to rest upon a number of fixed supporting legs which installed before on the bottom of the tank;
d. the longitudinal and traverse seams between adjacent modules of the working floor for the roof structure are sealed off at the bottom side of the roof structure by means of self-adhesive tape thereby forming a totally flat surface, whereafter for the prevention of gas and air inclusions, the seam slit is further filled up with synthetic material of the skin material of the sandwich module, the self adhesive tape being removed or not after hardening;
e. the flexible tank wall seal is thereafter mounted to the circumferential edge of the roof structure.
2. Floating roof structure which is composed, according to claim 1, of sandwich module boards and traverse frame profiles, characterized in that a traverse profile has a polygonal vertical cross section and is composed by two preferably rectangular tubular profiles, one on top of the other, particularly a lower tubular profile and on top of it an upper rectangular tubular profile, resting its short rectangular side.
3. Roof structure according to claim 2, characterized in that a number of cut-off profiles each time having a length of at least two times the width of a sandwich module is applied for, in such a way that every time the utmost ends of the lowermost square tubular profiles and also the utmost ends of the upper rightangled tubular profiles are always located in the central portion of the sandwich module.
4. Roof structure according to claim 3, characterized in that a cut-off profile has a length of about 1,000 mm whereas the total integral cross section of the traverse frame profile amounts to 50 x 50 and 50 x 30 square mm.
5. Roof structure according to claim 4, characterized in that the sandwich module preferably has a width of 500 mm and a length of 6,000 mm at a thickness of 50 mm.
6. Sandwich module to be used for a roof structure according to claim 5, characterized in that locally, in a direction perpendicular to its longitudinal axis, integral insert pieces of screwable material are provided at regular distances, preferably of hard screwable polylaminated wood (Multiplex), which pieces are incorporated in the foamed core material for the fixing of screws and suchlike fixing elements in and to the sandwich module.
7. Roof structure according to claims 2 to 5, characterized in that its bottom side is entirely flat except for the presence of a required manhole flange and various bushings (for cables, air inlets, air outlets, supporting legs) respectively.
8. Roof structure according to claim 7, characterized in that the floating roof structure is provided with a great number of adjustable support legs which equally support the entire roof structure on various locations with respect to the bottom of the tank.
9. Air inlet and air discharge means for a roof structure according to any one of the foregoing claims 2 to 5 and 7 to 8, characterized that a pot-shaped housing, consisting of a number of parts, is provided with at least one fixing flange for connecting it with the opening in a sandwich module and a cup shaped cover of the housing being provided with a number of air inlet and discharge openings respectively which are covered by a flexible non-return valve, a vertically movable bar being centrally positioned in the cover, which bar is provided at its upper end above the cover with an eyelet for connection to a cable and within the housing under the cover and perpendicular thereto said bar is provided with a number of closed discs, each having an outer circumferential downwardly directed cupshaped edge, whereas the inner side of said housing is provided with a number of corresponding downwardly directed funnel-shaped concentric baffles, in such a way that vapors passing through said means are forced to escape via this labyrinth seal.
10. Permanent magnet fixing means for keeping the floating roof structure according to claims 2 to 5 and 7 to 8 respectively in place with respect to the bottom of the tank by means of anti-rotation cables characterized in that a flat permanent magnet is provided horizontally and centrally respectively in at least two mutually perpendicular directions of a number of anti-tilting elements, one and the other in such a way that a possible tilting point or tilting line with respect to said magnet is located substantially far away and outwardly from the utmost borderline of the circumferential edge of the permanent magnet which holds to the bottom of the storage tank.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL9000684 | 1990-03-22 | ||
| NL9000684A NL9000684A (en) | 1990-03-22 | 1990-03-22 | FLOATING TANK ROOF OF PLASTIC MATERIAL. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2057921A1 true CA2057921A1 (en) | 1991-09-23 |
Family
ID=19856799
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002057921A Abandoned CA2057921A1 (en) | 1990-03-22 | 1991-03-22 | Floating roof of synthetic material for liquid storage tank |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0473778A1 (en) |
| JP (1) | JPH05504924A (en) |
| KR (1) | KR920701015A (en) |
| AU (1) | AU7781191A (en) |
| CA (1) | CA2057921A1 (en) |
| FI (1) | FI915467A0 (en) |
| NL (1) | NL9000684A (en) |
| TW (1) | TW221684B (en) |
| WO (1) | WO1991015418A1 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2003069075A1 (en) * | 2002-02-14 | 2003-08-21 | Devi Polymers Private Limited | A manhole access cover |
| US8177090B2 (en) | 2009-04-09 | 2012-05-15 | Saudi Arabian Oil Company | Storage tank with floating roof emergency draining system and spherical rotor fume sealing valve |
| EP3702398A1 (en) | 2019-02-26 | 2020-09-02 | World Link Industry Engineering GmbH | Floating roof for tanks, fire resistant coating thereof, and method for their manufacture |
| CN110015516A (en) * | 2019-04-28 | 2019-07-16 | 沃德林科环保设备（北京）有限公司 | A kind of new glass fibre reinforced plastic floating plate construction method |
| CN111348340A (en) * | 2020-03-09 | 2020-06-30 | 上海和达化工石油工程技术有限公司 | Efficient storage tank connects liquid floating plate entirely |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2007193A (en) * | 1932-12-05 | 1935-07-09 | Alvah M Griffin | Floating deck for oil storage tanks |
| DE1045323B (en) * | 1954-10-06 | 1958-11-27 | British Petroleum Co | Floating cover |
| GB839670A (en) * | 1957-11-21 | 1960-06-29 | Hammond Iron Works | Liquid storage floating cover |
| US3308984A (en) * | 1961-09-08 | 1967-03-14 | Baker Mfg Co | Float for hydraulic accumulator |
| US3240381A (en) * | 1962-01-02 | 1966-03-15 | Millard F Smith | Surface cover for stored liquids |
| US3587911A (en) * | 1969-04-01 | 1971-06-28 | Olin Mathieson | Floating deck for storage tank |
| FR2216815A5 (en) * | 1973-02-06 | 1974-08-30 | British Petroleum Co | |
| US4202460A (en) * | 1978-04-13 | 1980-05-13 | Imbeault Fernand A | Sectional floating cover |
| CH635551A5 (en) * | 1979-01-08 | 1983-04-15 | Edmund Bertil Sandborn | Construction unit for constructing floating covers for containers storing liquids, and a method for the manufacture thereof |
-
1990
- 1990-03-22 NL NL9000684A patent/NL9000684A/en not_active Application Discontinuation
-
1991
- 1991-03-22 AU AU77811/91A patent/AU7781191A/en not_active Abandoned
- 1991-03-22 WO PCT/NL1991/000044 patent/WO1991015418A1/en not_active Application Discontinuation
- 1991-03-22 JP JP3508544A patent/JPH05504924A/en active Pending
- 1991-03-22 KR KR1019910701658A patent/KR920701015A/en not_active Application Discontinuation
- 1991-03-22 CA CA002057921A patent/CA2057921A1/en not_active Abandoned
- 1991-03-22 EP EP91908878A patent/EP0473778A1/en not_active Withdrawn
- 1991-05-16 TW TW080103792A patent/TW221684B/zh active
- 1991-11-20 FI FI915467A patent/FI915467A0/en not_active Application Discontinuation
Also Published As
| Publication number | Publication date |
|---|---|
| WO1991015418A1 (en) | 1991-10-17 |
| FI915467A0 (en) | 1991-11-20 |
| JPH05504924A (en) | 1993-07-29 |
| AU7781191A (en) | 1991-10-30 |
| EP0473778A1 (en) | 1992-03-11 |
| KR920701015A (en) | 1992-08-10 |
| TW221684B (en) | 1994-03-11 |
| NL9000684A (en) | 1991-10-16 |
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