US3859805A - Flat bottom ship tank for transport of liquefied gas - Google Patents

Flat bottom ship tank for transport of liquefied gas Download PDF

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Publication number
US3859805A
US3859805A US440785A US44078574A US3859805A US 3859805 A US3859805 A US 3859805A US 440785 A US440785 A US 440785A US 44078574 A US44078574 A US 44078574A US 3859805 A US3859805 A US 3859805A
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US
United States
Prior art keywords
tank
skirt
ship
hold
section
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Expired - Lifetime
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US440785A
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English (en)
Inventor
Paul Richard Johnson
Jamshid Teymourian
Elmer Weyman Rothrock
Willis James Kircik
Kenneth Wilson Lange
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Chicago Bridge and Iron Co
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Chicago Bridge and Iron Co
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Filing date
Publication date
Priority to US440785A priority Critical patent/US3859805A/en
Application filed by Chicago Bridge and Iron Co filed Critical Chicago Bridge and Iron Co
Priority to CA214,757A priority patent/CA995523A/en
Priority to NL7415983A priority patent/NL7415983A/xx
Priority to ES432999A priority patent/ES432999A1/es
Priority to GB5480574A priority patent/GB1444869A/en
Priority to SE7500223A priority patent/SE7500223L/xx
Publication of US3859805A publication Critical patent/US3859805A/en
Application granted granted Critical
Priority to IT67167/75A priority patent/IT1027367B/it
Priority to DE19752504467 priority patent/DE2504467A1/de
Priority to BE153129A priority patent/BE825266A/xx
Priority to JP50014937A priority patent/JPS50118311A/ja
Priority to NO750393A priority patent/NO750393L/no
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B25/00—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby
    • B63B25/02—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods
    • B63B25/08—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods fluid
    • B63B25/12—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods fluid closed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
    • B63B25/00—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby
    • B63B25/02—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods
    • B63B25/08—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods fluid
    • B63B25/12—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods fluid closed
    • B63B25/16—Load-accommodating arrangements, e.g. stowing, trimming; Vessels characterised thereby for bulk goods fluid closed heat-insulated
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C3/00—Vessels not under pressure
    • F17C3/02—Vessels not under pressure with provision for thermal insulation
    • F17C3/025—Bulk storage in barges or on ships
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2201/00—Vessel construction, in particular geometry, arrangement or size
    • F17C2201/01—Shape
    • F17C2201/0104—Shape cylindrical
    • F17C2201/0109—Shape cylindrical with exteriorly curved end-piece
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2201/00—Vessel construction, in particular geometry, arrangement or size
    • F17C2201/01—Shape
    • F17C2201/0104—Shape cylindrical
    • F17C2201/0119—Shape cylindrical with flat end-piece
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2201/00—Vessel construction, in particular geometry, arrangement or size
    • F17C2201/01—Shape
    • F17C2201/0142—Shape conical
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2201/00—Vessel construction, in particular geometry, arrangement or size
    • F17C2201/01—Shape
    • F17C2201/0147—Shape complex
    • F17C2201/0166—Shape complex divided in several chambers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2201/00—Vessel construction, in particular geometry, arrangement or size
    • F17C2201/03—Orientation
    • F17C2201/035—Orientation with substantially horizontal main axis
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2201/00—Vessel construction, in particular geometry, arrangement or size
    • F17C2201/05—Size
    • F17C2201/052—Size large (>1000 m3)
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2203/00—Vessel construction, in particular walls or details thereof
    • F17C2203/01—Reinforcing or suspension means
    • F17C2203/011—Reinforcing means
    • F17C2203/013—Reinforcing means in the vessel, e.g. columns
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2203/00—Vessel construction, in particular walls or details thereof
    • F17C2203/03—Thermal insulations
    • F17C2203/0304—Thermal insulations by solid means
    • F17C2203/0354—Wood
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2203/00—Vessel construction, in particular walls or details thereof
    • F17C2203/06—Materials for walls or layers thereof; Properties or structures of walls or their materials
    • F17C2203/0602—Wall structures; Special features thereof
    • F17C2203/0612—Wall structures
    • F17C2203/0626—Multiple walls
    • F17C2203/0631—Three or more walls
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2203/00—Vessel construction, in particular walls or details thereof
    • F17C2203/06—Materials for walls or layers thereof; Properties or structures of walls or their materials
    • F17C2203/0634—Materials for walls or layers thereof
    • F17C2203/0636—Metals
    • F17C2203/0639—Steels
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2221/00—Handled fluid, in particular type of fluid
    • F17C2221/01—Pure fluids
    • F17C2221/012—Hydrogen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2221/00—Handled fluid, in particular type of fluid
    • F17C2221/01—Pure fluids
    • F17C2221/016—Noble gases (Ar, Kr, Xe)
    • F17C2221/017—Helium
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2221/00—Handled fluid, in particular type of fluid
    • F17C2221/03—Mixtures
    • F17C2221/032—Hydrocarbons
    • F17C2221/033—Methane, e.g. natural gas, CNG, LNG, GNL, GNC, PLNG
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2223/00—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel
    • F17C2223/01—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel characterised by the phase
    • F17C2223/0146—Two-phase
    • F17C2223/0153—Liquefied gas, e.g. LPG, GPL
    • F17C2223/0161—Liquefied gas, e.g. LPG, GPL cryogenic, e.g. LNG, GNL, PLNG
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2223/00—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel
    • F17C2223/03—Handled fluid before transfer, i.e. state of fluid when stored in the vessel or before transfer from the vessel characterised by the pressure level
    • F17C2223/033—Small pressure, e.g. for liquefied gas
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17C—VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES
    • F17C2270/00—Applications
    • F17C2270/01—Applications for fluid transport or storage
    • F17C2270/0102—Applications for fluid transport or storage on or in the water
    • F17C2270/0105—Ships
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/32—Hydrogen storage
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S220/00—Receptacles
    • Y10S220/901—Liquified gas content, cryogenic

Definitions

  • ABSTRACT A combination of a ship having a hold with a bottom and walls, and a tank, which is circular in horizontal section, for transporting a liquefied gas; said tank having a metal shell having (1) a substantially flat metal bottom (2) a spheroidal section constituting most of the upper part of the tank and 3) a toroidal knuckle portion tangentially joined to the periphery of the metal bottom and tangentially joined to the spheroidal section; load bearing insulation between the ship hold bottom and the tank metal bottom; and a skirt, circular in horizontal section, extending from the tank above the toroidal knuckle portion downwardly to a supporting base in the ship hold.
  • This invention relates to ships used for transporting cryogenic liquefied gases. More particularly, this invention is concerned with improvements in ship tanks for transporting cryogenic liquefied gases and which tanks are separate, independent, structures supported by and anchored to the ship bottom and not necessarily otherwise dependent on the ship hull or hold structure for support.
  • gases can be liquefied at moderate pressures and shipped in tanks capable of maintaining the gas under such pressure to keep it in the liquefied state. Because the pressure needed to liquefy some gases at atmospheric temperature is not unduly great, the pressure vessel required for storage of the so-liquefied gas can be built of a relatively large size economically. Other gases, however, cannot be readily liquefied even at fairly high pressures unless the temperature of the gas is also reduced substantially below atmospheric temperature.
  • cryogenic liquefied gas Because it is difficult and expensive to construct a pressure vessel capable of storing a cryogenic liquefied gas at high pressure in large volume, it has been found more practical and less expensive to cool the liquefied gas to a temperature at which it can be stored in a tank designed to withstand a minimum internal pressure plus of course the expected dynamic loads due to ship motions. For example, it has been found convenient to store liquefied natural gas, which is essentially methane, at about 260F. and at about psia or just slightly above atmospheric pressure. Other cryogenic liquefied gases such as hydrogen, helium and ethylene can be similarly stored at about at mospheric pressure following their refrigeration to a temperature below the boiling point .of the gas at such pressure.
  • Tanks for transporting cryogenic liquefied gases at about atmospheric pressure in a ship are of two main types.
  • One type of tank is a membrane tank in which the tank walls and bottom are substantially continuously supported by the ship hull structure. Such a tank relies upon the structure of the ship for the strength and support needed to contain the liquid being stored.
  • Another type of tank is a structurally self-supporting or free-standing vessel or tank which is spaced or separated from the ship hold bottom and walls. Such a vessel or tank does not rely on the strength of the hold walls for necessary reinforcement because it is structurally independent of the ship hold walls insofar as its ability to effectively contain the stored liquid is concerned.
  • Spherical tanks have been mounted in the ship hold on a metal cylindrical skirt with the tank bottom located above the ship hold bottom. See U.S. Pat. Nos. 3,677,021 and 3,680,323. While such tanks are suitable for liquefied gas transport by ship, they do not occupy as much of the total hold space as would be desired for maximum capacity. The amount of nonusable space between the tank and the ship hold is unduly large and for efficient, more economical transport this space should be reduced and the tank occupy a higher percentage of the hold space. Also, such tanks required all liquid load to go to the perimeter of the tank and to then be redistributed to the ship bottom. This is not efficient or economical.
  • the spherical pressure vessel tank as mounted in a ship hold according to the prior art extends considerably above the ship deck and this causes the center of gravity of the ship to be higher than desired when the tanks are full of a liquefied gas.
  • a ship having a hold with a bottom and walls, and a tank, which is circular in horizontalsection, positioned in the hold for transporting a liquefied gas.
  • the tank is characterized by a metal shell which has the following three main shell. sections or portions: (1) a substantially flat metal bottom, (2) a spheroidal section constituting most of the upper part of the tank, and (3) a toroidal knuckle portion tangentially joined to the periphery of the metal bottom and tangentially joined to the spheroidal section.
  • Located between the ship hold bottom and the tank metal bottom is load bearing insulation upon which the: tank bottom rests.
  • skirt circular in horizontal sectiomextencls from the tank above the toroidal knuckle portion downwardly to a supporting base in the ship hold.
  • the described tank of this invention permits most of the hydrostatic load from liquid in the tank to be transferred directly and substantially uniformly through the insulation to the ship hold bottom. Only part of the load must go thru the skirt and be redistributed to the hold bottom.
  • the tank bottom since it is supported by load bearing insulation, need not be made as thick as the major spheroidal shell portion of the tank which, to meet code and safety requirements, is built to pressure vessel standards.
  • a tank with such a relatively thin bottom is a hybrid tank in that the thin bottom is in the nature of a semi-membrane while most if not all of the remaining tank shell is of independent free standing vessel construction which must contain the internal pressure by stress in the shell.
  • the bottom is, however, to some extent in tension when the tank is loaded because of the forces applied against the toroidal knuckle.
  • the internal pressure due to liquid cargo is primarily applied downwardly on the tank bottom and thereby is transferred to the ship hold bottom.
  • the toroidal knuckle extending upwardly and outwardly in a curved manner from the tank flat bottom is generally at least as thick as the tank bottom. It can be thicker however; for example, it can have a thickmess up to or greater than the thickness of the spheroidal shell portion of the tank. It is furthermore considered most suitable for the toroidal knuckle when viewed in vertical cross-section to be tapered from a thin thickness, which can be about the same as the thickness of the tank bottom where it joins the tank flat bottom, to a greater thickness where it joins the spheroidal part of the tank.
  • the spheroidal section can be spherical, elipsoidal or conispherical in which a conical portion joins the toroidal knuckle to an upper spherical section. Regardless of the particular shape, it joins the toroidal knuckle tangentially in a smooth curve.
  • the supporting circular skirt is an essential part of the tank support system.
  • the skirt supports some of the hydrostatic load when the tank is full.
  • the skirt supports much of the load from the periphery of the tank flat bottom outwardly to the width of the tank. More importantly, however, the skirt supports the tank stably during the various motions which the ship may encounter.
  • The'skirt transmits reactions resulting from horizontal loads and overturning movements to the ship structure.
  • the skirt is essential in resisting the forces encountered at sea.
  • the skirt can be joined to the tank at its equator or widest part, or at some location below the equator. Regardless of where the skirt joins the tank it is structurally desirable for the joint to be tangential.
  • the lower end of the skirt can be joined to the ship hold bottom or some other supporting base in the hold.
  • the skirt can be a vertically positioned circular cylindrical shell, or a conical section shell generally with the largest end at the top.
  • the tank Since the tank is intended to transport a cryogenic liquefied gas, it is insulated to reduce heat leak into the tank.
  • the insulation is advisably extended down the skirt to the skirt-supporting base.
  • the internal lower part of the skirt is also advisably insulated to effect development of a suitable thermal gradient from the very low temperature where the skirt joins the tank to the much higher, more or less ambient temperature of the skirt-supporting base.
  • a suitable spray shield is placed around the tank, inside or over the insulation, to entrap any liquid escaping in the event a crack develops in the tank shell, and to direct the escaped liquid to a drip pan below the tank.
  • a drip pan of suitable sheet material is placed beneath the entire tank flat bottom but above the ship hold bottom.
  • the drip pan collects the cold liquid and prevents it from contacting and cooling the ship hull to a temperature which might lead to failure of the carbon steel from which a ship hull is normally made.
  • the described flat bottom, self-supporting tank occupies a larger amount of the space in a ship hold than a spherical tank and as a result can carry a larger volume of liquid.
  • the invention reduces the cost of a suitable storage tank, as well as the cost of a ship hull, by directly transferring much of the product load to the ship bottom.
  • the required capacity of the inerting system is also reduced by reduction of the empty space between the tank and ship hold.
  • the inherently lower profile of the tank lowers the center of gravity of the ship when both empty and loaded compared to a ship having a spherical tank in the same size hold. The lower profile allows improved visability over that allowed by a spherical tank, thus improving ship operation.
  • the top of a flat bottom tank of this invention can be made as much as twenty feet lower in elevation than a spherical tank of equal capacity.
  • FIG. 1 is a vertical sectional view through the width of a ship containing a conispherical tank with a flat bottom according to the invention
  • FIG. 2 is an enlarged view of the lower part of the tank and ship hold shown in FIG. 1;
  • FIG. 3 is a vertical sectional view through the width of a ship containing a spherical tank with a flat bottom according to the invention
  • FIG. 4 is an enlarged view of the lower part of the tank and ship hold shown in FIG. 3;
  • FIG. 5 is an enlarged view of the lower part of a tank in a ship hold and illustrates a tank with a tapered toroidal knuckle portion.
  • ship 10 has a hold 11 defined by hold bottom 12 and hold walls 14. Inside of the ship hold is positioned conispherical tank 20.
  • Tank 20 circular in horizontal section, has a substantially flat relatively thin bottom 21 of metal plate which slidably rests on a layer of support material'22 placed over liquid impermeable flexible membrane 23 supported on top of load bearing insulation 24.
  • Tank bottom 21 is essentially circular. It is joined tangentially at its periphery, such as by welding, to metal toroidal knuckle portion 25 which is joined at its upper peripheral edge, such as by welding, to ring 26.
  • the tank bottom 21 generally can be made thinner than the maximum thickness of the toroidal knuckle portion since the hydrostatic load is applied against the tank bottom and it, in turn, is transferred through the support material 22, which can be balsa wood, and load bearing insulation 24 to the ship hold bottom 12.
  • a conical section 27 is joined, such as by welding, at its lower edge to ring 26 and at its upper edge to spherical section 28 which completes the tank major structural elements.
  • the conical section 27, the spherical section 28 and the ring 26 together are encompassed within the term spheroidal-section as that term is used herein in describing the invention.
  • Equipment well 29 extends inside the tank for its full height and is used for piping, pump and monitoring equipment associated with the tank.
  • conical skirt 30 Projecting downwardly from the lower outer edge of ring 26 is conical skirt 30.
  • the lower edge of conical skirt 30 is joined to plate31 which is bolted to plate 32 supported by upright metal plate 33, thereby forming a bolted transition connection which permits the tank to be secured in position to the ship hold bottom even though the skirt and ship hold bottom are made of dissimilar metals which are not directly weldable.
  • the means used to join the lower edge of the skirt to the ship hold bottom is, however, not a critical part of the invention and other suitable means can be used.
  • a series of weep holes 34 extend through skirt 30 for delivery of escaped liquid to drip accumulating space 35.
  • Insulation 36 is placed over the inner lower portion of conical skirt 30 and the membrane 23 is extended upwardly on the surface of that insulation to angle shield 37.
  • the external surface of tank 20, and the external surface of conical skirt 30, are covered by insulation 38 and over the insulation is placed spray shield 39.
  • the lower edge of the spray shield 39 terminates in angle gutter 40 which directs accumulated liquid through weep holes 34.
  • the lower part of the insulation 38 on conical skirt 30 is covered with a vapor barrier coating 41, such as of butyl rubber.
  • Weather shield 42 is placed over the entire tank part which extends above the ship deck.
  • Insulation of the conical skirt in the manner previously described leads to development of a uniform thermal gradient through the skirt height, from very cold product temperatures in the skirt upper part to about ambient (i.e. ship hull temperature) or atmospheric temperature in the skirt lower part, which results in thermal stresses within allowable design limits.
  • the skirt base is at approximately ambient temperature so that carbon steel can be used in the ship hold construction.
  • the tank described with reference to FIGS. 1 and 2 has better utilization of ship hold space than a spherical tank. As a result, such a tank will have less overall height than a spherical tank, permitting a lower center of gravity and lower profile in the ship thereby increasing visability from the ship deck. Furthermore, by better utilizing the ship hold space there is less residual space which must be inerted. This thereby minimizes the capacity of the inerting system and results in a significant savings in initial cost and operation.
  • the volume tank of FIGS. 1 and 2 can be increased or decreased by adjusting the length of the conical portion, the conical angle, or the radius of the spherical portion of the conispherical tank. This can have the advantage of permitting an increase in tank volume without changing the ship breadth.
  • a spherical tank can only be adjusted by changing its radius so that a larger tank will require a larger ship breadth.
  • FIGS. 3 and 4 A further embodiment of the invention is shown in FIGS. 3 and 4.
  • Ship 50 shown in partial lateral crosssection through its width, has a hold 51 defined by a bottom 52 and hold walls 53.
  • Loadbearing insulation 54 is placed on hold bottom 52 and secondary barrier 55 is positioned on top of the insulation.
  • a layer of support material 56 is placed on top of the secondary barrier 55.
  • Tank flat bottom 57 having a circular periphery, rests on layer 56.
  • the tank bottom 57 is made of thin metal plate.
  • Toroidal knuckle 58 is welded at its lower edge to the peripheral edge of the tank bottom and at its upper edge 59 to-spherical section 60.
  • the upper edge of spherical section 60 is welded to metal ring 61.
  • Spherical section 62 which is an approximately hemispherical section, is joined at its lower edge, by welding, to the top edge of ring 61.
  • Vertically positioned cylindrical metal skirt 63 is joined to ring 61 by welding the upper edge of the skirt to the lower outer edge of the ring.
  • the bottom edge of skirt 63 is joined to plate 64 and it is bolted to plate 65 supported by base plate 66.
  • Base plate 66 is welded to a horizontal ledge in the lower part of the hold. Such a transition joint is not always necessary to join the lower edge of a skirt to the ship hold bottom.
  • a skirt made of.9% nickel could be welded directly to a carbon steel ship hold bottom.
  • Insulation 67 is positioned over the internal lower portion of skirt 63 and barrier or membrane 55 is extended upwardly over the insulation to angle shield 68.
  • Insulation 69 is located on the external surface of the tank, above ring 61, and on the external surface of the skirt 63.
  • Spray shield 70 covers the insulation on the outside of the tank down to angle gutter 71.
  • Vapor barrier coating 72 is positioned over the outside of the insulation on the external surface of the skirt from below the angle gutter 71 down to the bottom edge of the skirt.
  • Weather shield 73 covers the top of the tank and extends to the hold top or ship deck to protect the hold interior.
  • Equipment well 74 extends for the full height of the tank.
  • FIG. 5 illustrates another embodiment of the invention but one which is very similar to the one shown in FIG. 2.
  • the embodiment shown in FIG. 5 however employs a toroidal knuckle 255 which is made of tapered metal plate when viewed in vertical radial section.
  • the bottom peripheral edge 256 has the same thickness as the tank bottom 21 and the upper peripheral edge 257 has the same thickness as spherical section 260 extending between the toroidal knuckel and ring 26.
  • said tank comprising a metal shell having ll a substantially flat metal bottom (2) a spheroidal section constituting most of the upper part of the tank and (3) a toroidal knuckle portion tangentially joined to the periphry of the metal button and tangentially joined to the spheroidal section;

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Ocean & Marine Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Filling Or Discharging Of Gas Storage Vessels (AREA)
US440785A 1974-02-08 1974-02-08 Flat bottom ship tank for transport of liquefied gas Expired - Lifetime US3859805A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
US440785A US3859805A (en) 1974-02-08 1974-02-08 Flat bottom ship tank for transport of liquefied gas
CA214,757A CA995523A (en) 1974-02-08 1974-11-27 Flat bottom ship tank for transport of liquefied gas
NL7415983A NL7415983A (nl) 1974-02-08 1974-12-09 Vloeigastanker.
ES432999A ES432999A1 (es) 1974-02-08 1974-12-17 Perfeccionamientos introducidos en un buque en combinacion con un deposito.
GB5480574A GB1444869A (en) 1974-02-08 1974-12-18 Ships for transporting cryogenic liquefied gases
SE7500223A SE7500223L (no) 1974-02-08 1975-01-09
IT67167/75A IT1027367B (it) 1974-02-08 1975-01-24 Serbatoio a fondo piano per navi per il trasporto di gas liquefatti
DE19752504467 DE2504467A1 (de) 1974-02-08 1975-02-04 Schiff mit behaelter zum transport von fluessiggas
BE153129A BE825266A (fr) 1974-02-08 1975-02-06 Citerne de navire a fond plat pour le transport de gaz liquifie
JP50014937A JPS50118311A (no) 1974-02-08 1975-02-06
NO750393A NO750393L (no) 1974-02-08 1975-02-07

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US440785A US3859805A (en) 1974-02-08 1974-02-08 Flat bottom ship tank for transport of liquefied gas

Publications (1)

Publication Number Publication Date
US3859805A true US3859805A (en) 1975-01-14

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US440785A Expired - Lifetime US3859805A (en) 1974-02-08 1974-02-08 Flat bottom ship tank for transport of liquefied gas

Country Status (11)

Country Link
US (1) US3859805A (no)
JP (1) JPS50118311A (no)
BE (1) BE825266A (no)
CA (1) CA995523A (no)
DE (1) DE2504467A1 (no)
ES (1) ES432999A1 (no)
GB (1) GB1444869A (no)
IT (1) IT1027367B (no)
NL (1) NL7415983A (no)
NO (1) NO750393L (no)
SE (1) SE7500223L (no)

Cited By (18)

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Publication number Priority date Publication date Assignee Title
US3968764A (en) * 1974-10-31 1976-07-13 Moss Rosenberg Verft A/S Ships for transport of liquefied gases
US4011964A (en) * 1975-04-24 1977-03-15 Moss Rosenberg Verft A/S Equatorial profile for large spherical tanks
DE2726401A1 (de) * 1976-08-23 1978-03-02 Moss Rosenberg Verft As Vorrichtung bei einem isolierten tank
US4106423A (en) * 1976-10-28 1978-08-15 General Dynamics Corporation Weather covers for tankers
US4140073A (en) * 1977-07-12 1979-02-20 Frigitemp Corporation Thermal barrier system for liquefied gas tank
US4394931A (en) * 1980-04-25 1983-07-26 Shell Internationale Research Maatschappij B. V. Heat-insulated container provided with a locating and/or supporting device
EP0168615A1 (en) * 1984-06-08 1986-01-22 Mitsubishi Jukogyo Kabushiki Kaisha Freight carrier's hull construction for carrying cryogenic or high temperature freight
JPS6180290U (no) * 1985-10-24 1986-05-28
EP0453617A1 (en) * 1990-04-27 1991-10-30 Mitsubishi Jukogyo Kabushiki Kaisha Ship for carrying liquefied gas
US6626319B2 (en) 2001-06-04 2003-09-30 Electric Boat Corporation Integrated tank erection and support carriage for a semi-membrane LNG tank
US20090199760A1 (en) * 2007-12-03 2009-08-13 Nli Innovation As Liquefied gas tank with a central hub in the bottom structure
CN100577510C (zh) * 2003-09-24 2010-01-06 三菱重工业株式会社 罐盖及船舶
WO2010098673A1 (en) * 2009-02-27 2010-09-02 Sevan Marine Asa Flexible lower tank
NO329738B1 (no) * 2007-10-23 2010-12-13 Sevan Marine Asa Tank for transport og lagring av flytende gass
WO2011053154A1 (en) * 2009-10-29 2011-05-05 Aker Engineering & Technology As Tank with inclined walls
NO20121344A1 (no) * 2012-11-13 2014-05-14 Nli Innovation As Støttekonstruksjon
WO2014076119A1 (en) * 2012-11-13 2014-05-22 Nli Innovation As Support assembly
US20180072387A1 (en) * 2015-04-10 2018-03-15 Mitsubishi Heavy Industries, Ltd. Non-spherical tank and liquefied gas carrier ship equipped with the non-spherical tanks

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JPS5374895U (no) * 1976-11-25 1978-06-22
JPS5663088U (no) * 1979-10-19 1981-05-27
JPS57153658U (no) * 1981-03-23 1982-09-27
JPS57158186A (en) * 1981-03-23 1982-09-29 Mitsubishi Heavy Ind Ltd Tanker for transportation of melted material at high temperature
DE3309395C2 (de) * 1982-03-19 1986-07-10 Ishikawajima-Harima Jukogyo K.K., Tokio/Tokyo Großraum-Lagerbehälter
JPS60263799A (ja) * 1984-06-11 1985-12-27 Mitsubishi Heavy Ind Ltd 低温又は高温貨物輸送用の船舶
JPH0665556B2 (ja) * 1986-01-08 1994-08-24 三菱重工業株式会社 船舶における円筒形タンクの建造法
GB2535397B (en) * 2014-02-28 2017-10-04 Mgi Thermo Pte Ltd An LNG fuel containment apparatus incorporating multi-layered insulation panels

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US2993460A (en) * 1958-05-29 1961-07-25 California Research Corp Tank support
US3224623A (en) * 1963-05-20 1965-12-21 Martin Marietta Corp Liquefied gas container insulation
US3680323A (en) * 1969-10-18 1972-08-01 Kvaerner Brug As Tanker for liquified and/or compressed gas
US3692205A (en) * 1970-02-27 1972-09-19 Exxon Research Engineering Co Drip pan lng tank
US3770158A (en) * 1971-05-24 1973-11-06 Technigaz Device for protecting the environment of a tank against failures thereof

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JPS4841485A (no) * 1971-10-01 1973-06-18

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Publication number Priority date Publication date Assignee Title
US2993460A (en) * 1958-05-29 1961-07-25 California Research Corp Tank support
US3224623A (en) * 1963-05-20 1965-12-21 Martin Marietta Corp Liquefied gas container insulation
US3680323A (en) * 1969-10-18 1972-08-01 Kvaerner Brug As Tanker for liquified and/or compressed gas
US3692205A (en) * 1970-02-27 1972-09-19 Exxon Research Engineering Co Drip pan lng tank
US3770158A (en) * 1971-05-24 1973-11-06 Technigaz Device for protecting the environment of a tank against failures thereof

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3968764A (en) * 1974-10-31 1976-07-13 Moss Rosenberg Verft A/S Ships for transport of liquefied gases
US4011964A (en) * 1975-04-24 1977-03-15 Moss Rosenberg Verft A/S Equatorial profile for large spherical tanks
DE2726401A1 (de) * 1976-08-23 1978-03-02 Moss Rosenberg Verft As Vorrichtung bei einem isolierten tank
DK151473B (da) * 1976-10-28 1987-12-07 Gen Dynamics Corp Lastskib til transport af nedkoelet gas i flydende form
US4106423A (en) * 1976-10-28 1978-08-15 General Dynamics Corporation Weather covers for tankers
US4140073A (en) * 1977-07-12 1979-02-20 Frigitemp Corporation Thermal barrier system for liquefied gas tank
US4394931A (en) * 1980-04-25 1983-07-26 Shell Internationale Research Maatschappij B. V. Heat-insulated container provided with a locating and/or supporting device
US4672906A (en) * 1984-06-08 1987-06-16 Mitsubishi Jukogyo Kabushiki Kaisha Freight carrier's hull construction for carrying cryogenic or high temperature freight
EP0168615A1 (en) * 1984-06-08 1986-01-22 Mitsubishi Jukogyo Kabushiki Kaisha Freight carrier's hull construction for carrying cryogenic or high temperature freight
JPS6180290U (no) * 1985-10-24 1986-05-28
EP0453617A1 (en) * 1990-04-27 1991-10-30 Mitsubishi Jukogyo Kabushiki Kaisha Ship for carrying liquefied gas
US6626319B2 (en) 2001-06-04 2003-09-30 Electric Boat Corporation Integrated tank erection and support carriage for a semi-membrane LNG tank
CN100577510C (zh) * 2003-09-24 2010-01-06 三菱重工业株式会社 罐盖及船舶
NO329738B1 (no) * 2007-10-23 2010-12-13 Sevan Marine Asa Tank for transport og lagring av flytende gass
US8091494B2 (en) * 2007-12-03 2012-01-10 Nli Innovation As Liquefied gas tank with a central hub in the bottom structure
US20090199760A1 (en) * 2007-12-03 2009-08-13 Nli Innovation As Liquefied gas tank with a central hub in the bottom structure
WO2010098673A1 (en) * 2009-02-27 2010-09-02 Sevan Marine Asa Flexible lower tank
CN102325690A (zh) * 2009-02-27 2012-01-18 塞万海洋股份有限公司 具有柔韧下部的储罐
NO332284B1 (no) * 2009-02-27 2012-08-13 Sevan Marine Asa Kryogenisk tank for bruk i fartøy
CN102325690B (zh) * 2009-02-27 2014-10-15 塞万海洋股份有限公司 具有柔韧下部的储罐
WO2011053154A1 (en) * 2009-10-29 2011-05-05 Aker Engineering & Technology As Tank with inclined walls
CN102770340A (zh) * 2009-10-29 2012-11-07 阿克工程和技术公司 带有倾斜壁的储箱
JP2013509324A (ja) * 2009-10-29 2013-03-14 アーケル・エンジニアリング・アンド・テクノロジー・アクティーゼルスカブ 傾斜壁を有するタンク
RU2526147C2 (ru) * 2009-10-29 2014-08-20 Акер Инжиниринг & Текнолоджи Ас Резервуар с наклонными стенками
NO20121344A1 (no) * 2012-11-13 2014-05-14 Nli Innovation As Støttekonstruksjon
WO2014076119A1 (en) * 2012-11-13 2014-05-22 Nli Innovation As Support assembly
CN104981397A (zh) * 2012-11-13 2015-10-14 Nli创新公司 支撑组件
US20180072387A1 (en) * 2015-04-10 2018-03-15 Mitsubishi Heavy Industries, Ltd. Non-spherical tank and liquefied gas carrier ship equipped with the non-spherical tanks
US10450039B2 (en) * 2015-04-10 2019-10-22 Mitsubishi Shipbuilding Co., Ltd. Non-spherical tank and liquefied gas carrier ship equipped with the non-spherical tanks

Also Published As

Publication number Publication date
SE7500223L (no) 1975-08-11
NO750393L (no) 1975-09-01
IT1027367B (it) 1978-11-20
ES432999A1 (es) 1976-09-01
BE825266A (fr) 1975-05-29
NL7415983A (nl) 1975-08-12
DE2504467A1 (de) 1975-08-14
CA995523A (en) 1976-08-24
JPS50118311A (no) 1975-09-17
GB1444869A (en) 1976-08-04

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