US3895885A - Emptying system for fluid tanks - Google Patents

Emptying system for fluid tanks Download PDF

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Publication number
US3895885A
US3895885A US320828A US32082873A US3895885A US 3895885 A US3895885 A US 3895885A US 320828 A US320828 A US 320828A US 32082873 A US32082873 A US 32082873A US 3895885 A US3895885 A US 3895885A
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US
United States
Prior art keywords
liquid
gas
pump
separator tank
container
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.)
Expired - Lifetime
Application number
US320828A
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English (en)
Inventor
Lars-Olof Liberg
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jonkopings Mekaniska Werkstads AB
Original Assignee
Jonkopings Mekaniska Werkstads AB
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Publication of US3895885A publication Critical patent/US3895885A/en
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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 
    • B63B27/00—Arrangement of ship-based loading or unloading equipment for cargo or passengers
    • B63B27/24—Arrangement of ship-based loading or unloading equipment for cargo or passengers of pipe-lines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D31/00—Pumping liquids and elastic fluids at the same time
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D9/00—Priming; Preventing vapour lock
    • F04D9/001—Preventing vapour lock

Definitions

  • Gas in the 261/20, 36 R, 70, 76 separator tank is mixed in the form of smell bubbles into the oil on the suction side of the pump and is [56] References Cited evacuated distributed in the oil together therewith by UNITED STATES PATENTS the cenmfugal P 2,223,112 11/1940 Lear 417/77 X 13 Claims, 2 Drawing Figures EMPTYING SYSTEM FOR FLUID TANKS
  • This invention relates to a method of emptying a cargo oil tank or another container for oil or another liquid by means of a centrifugal pump, the suction pipe of which is connected to the container through a separator tank or the like, which is provided for separation of gas (air) and/or vapor, which follows the liquid into the separator tank.
  • the invention further relates to an apparatus for carrying out this method which comprises a cargo oil tank or another liquid container and a centrifugal pump which is provided for emptying said container and has its suction pipe connected to the container through a separator tank which is provided for the separation of gas (air) and/or vapor from the liquid on its way from the container. to the pump.
  • a vacuum pump for maintaining a vacuum or underpressure in the separator tank and for evacuating gas which is separated therein, and extensive controlling and checking equipment for the centrifugal pump, as well as for the vacuum pump.
  • the principal object of the invention is to simplify the stripping pumping and the equipment necessary therefor.
  • This object is achieved according to the method of the present invention by the fact that the gas (air) and/or vapor in the separator tank is mixed in the form of bubbles into the liquid on the suction side of the centrifugal pump and is evacuated distributed in the liquid together therewith by the centrifugal pump.
  • the apparatus according to the invention is characterized by the provision of means for recirculating liquid from the pressure pipe of the pump to a device, which is suitably located in the separator tank, for mixing gas (air) and/or vapor which is present in the separator tank, in a more or less finely diffused form into the recirculated liquid,
  • the basic principle on which the invention is based resides in the concept of finely diffusing gas, which has penetrated into the suction pipe of the pump, in such a way that the gas-liquid mixture becomes pumpable.
  • the pressure created by the pump drops on account of the decrease in density of the pump fluid due to the gas introduced therein.
  • the decrease in pressure has the consequence that the quantity of fluid pumped will decrease.
  • part of the gas may be separated out in the pump wheel and thereby block part of the flow space, which also leads to a decrease in the flow of fluid.
  • This drop in the flow of fluid will, in its turn, have the consequence that the leakage of gas into the suction pipe is reduced.
  • gas which penetrates into the suction pipe is utilized for controlling the quantity of liquid pumped, so that a balance is reached between the leakage of gas into the suction pipe and the capability of the pump to pump air.
  • part of the liquid being pumped is recirculated from the pressure pipe of the pump to the separator tank, in a preferred embodiment of the invention.
  • the energy of the recirculated liquid is utilized to finely diffuse the air separated in the separator tank, in the liquid being pumped.
  • the liquid level in the separator tank governs the amount of gas which is mixed with the liquid, and accordingly also the volume of the flow through the pump.
  • FIG. 1 illustrates in side view and in a very simplified way the principal parts of a pump system which is designed according to the invention.
  • FIG. 2 illustrates in the same way a modification of the system according to FIG. 1.
  • FIG. 1 designates a suction pipe which comes from a cargo oil tank 14 or from another arbitrary container, and 2 a separator tank which in its lower portion is connected to the inlet piece 4 of a cargo oil pump 3 or the like.
  • the inlet of the suction pipe 1 in the separator tank 2 is located in the upper portion thereof according to FIG. 1.
  • the separator tank is, by means of a vertical intermediate wall 5, divided into an inlet portion 2a and an outlet portion 2b which have a connection with each other only above the upper edge of the intermediate wall 5.
  • the cargo oil pump 3 has a pressure pipe 6 which, in a conventional manner is provided with a non-return valve 7.
  • a return or feed back-conduit 8 is branched off from the pressure pipe 6 from the lower side of a suitably substantially horizontal portion of the pressure pipe, which preferably is located comparatively high above the pump 3, where gas and oil have had time to separate so that only liquid is returned through feed back conduit 8.
  • the return conduit opens into a gas introduction or admixing device which is suitably located in the separator tank 2, or in its outlet portion 2b respectively. and is preferably of the jet pump or ejector type.
  • This gas introduction device which is generally designated 9,
  • the return conduit 8 is provided with an adjustment or shut off valve 10 which is operated automatically by a liquid level switch 11 or in another suitable manner depending upon the liquid level in the separator tank.
  • a substantially vertical gas tube 12 which is located in the separator tank and has small orifices or nozzles 13 which are provided in the tube wall and have a suitable area and a suitable mutual spacing.
  • the liquid absorbs or sucks off gas in finely diffused form, i.e. in the form of bigger or smaller bubbles, from the separator tank 2 into the pump 3.
  • the recirculated liquid has a greater velocity than the liquid not recirculated in the inlet piece 4 of the pump.
  • the device is, to the greatest extent possible, designed in such a way that the gas-liquid mixture becomes so uniformly small bubbly that the mixture becomes pumpable.
  • the gas-liquid mixture recirculated to the pump 3 may be introduced directed directly towards the inlet of the pump wheel for breaking down ,possible accumulations of gas there.
  • the mixture may be introduced into the inlet of the pump in such a way that a suitable prerotation is created therein.
  • the tube 12 may be provided with a slidable nad/or rotatable sleeve or the like which is so arranged that it covers a desired number of orifices by beeing displaced or rotated. Thanks to this arrangement the advantage is gained that the total area of uncovered orifices may be adapted to the capability of the pump to pump air, at every particular instance of operation.
  • the liquid level in the separator tank controls the amount of gas to the tube 12 by permitting gas to reach the gas introduction or admixing unit 9 solely through those orifices in the tube 12 which are situated above the liquid surface.
  • the mode of operation may be summarized as follows:
  • the separator tank 2 During normal discharge of oil from the cargo oil tank through the suction pipe 1 by means of the centrifugal pump 3, i.e., before said tank starts to get empty, the separator tank 2 is full of oil and the pump 3 thus just pumps plain oil.
  • the pump 3 When most of the oil in the cargo oil tank has been evacuated, i.e. during the final stage or the so called stripping pumping, air is sucked into the suction pipe 1 from the cargo oil tank.
  • the liquid level in the separator tank 2 drops and the air sucked in separates from the oil in the separator tank 2 and accumulates above the oil surface therein, as is known in the pump art.
  • the centrifugal pump 3 When the oil or liquid tank 2 is empty or when the flow of liquid in the suction pipe 1 has ceased for another reason, the centrifugal pump 3 still receives a flow of liquid from the liquid recirculated in the conduit 8. Thanks to the recirculation the pump wheel gets such flow of liquid as is necessary to prevent the pump from dropping, whereby the system can maintain the pumping (or stripping) when the suction pipe is anew supplied with liquid. Such an intermittent flow can arise, e.g. when pumping from a tank with a long suction pipe aboard a tanker.
  • the return pipe 8 is suitably so dimensioned and the flow of liquid through the same so adjusted that it can conduct from zero (before the stripping pumping, when the separator tank is full of liquid) up till the quantity of recirculating liquid which is necessary for the functioning at the current load condition (at empty cargo oil tank).
  • the system may be utilized for other purposes than the pumping of oil, e.g. from tankers.
  • the liquid level switch 11 for instance may be replaced by a control device, by means of which the proportions gas/liquid in the gasliquid mix- ;ure supplied to the pump is controlled in direct dependence upon the proportions of gas/liquid in the separator tank.
  • Method of emptying a container for liquid by means of a centrifugal pump having a pressure pipe, a pump impeller, and an inlet which is connected by a suction pipe to said container through a separator tank provided for separation of gas combined with the liquid as they are drawn from said container into the separator tank, comprising the steps of:
  • Method according to claim 1 comprising the steps of recirculating liquid from the pressure pipe of the pump to said separator tank, finely diffusing said gas in said recirculated liquid, and evacuating a mixture of diffused gas and liquid by said centrifugal pump.
  • Apparatus according to claim 10 in which said means for mixing gas into the recirculated liquid and for introducing the mixture into the inlet of the pump comprises an ejector means.
  • said means for mixing gas into the recirculated liquid comprises a substantially vertical tube which is provided in the separator tank and has a slightly shorter vertical extension than the separator tank, has a plurality of orifices, which are provided in the tube wall above and below each other, respectively, and has its lower end connected through an ejector means to the pressure pipe of the pump by a return duct.
  • Apparatus according to claim 10 comprising a return duct, a control valve in said return duct, a level gauge associated with said separator tank and said valve and operating in dependence of the level upon the liquid surface in said separator tank for opening said valve in the return duct when said liquid surface drops below a predetermined level.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Ocean & Marine Engineering (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
  • Centrifugal Separators (AREA)
  • Degasification And Air Bubble Elimination (AREA)
  • Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)
US320828A 1972-01-12 1973-01-03 Emptying system for fluid tanks Expired - Lifetime US3895885A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE00303/72A SE366702B (ja) 1972-01-12 1972-01-12

Publications (1)

Publication Number Publication Date
US3895885A true US3895885A (en) 1975-07-22

Family

ID=20256336

Family Applications (1)

Application Number Title Priority Date Filing Date
US320828A Expired - Lifetime US3895885A (en) 1972-01-12 1973-01-03 Emptying system for fluid tanks

Country Status (9)

Country Link
US (1) US3895885A (ja)
JP (1) JPS4880466A (ja)
DE (1) DE2301012A1 (ja)
ES (1) ES410515A1 (ja)
FR (1) FR2168111A1 (ja)
GB (1) GB1412215A (ja)
IT (1) IT976778B (ja)
NL (1) NL7300424A (ja)
SE (1) SE366702B (ja)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4147474A (en) * 1976-12-28 1979-04-03 Norsk Hydro A.S Method and system for transferring liquid media
US4249864A (en) * 1978-06-19 1981-02-10 Auscoteng Pty. Ltd. Centrifugal pump system for water desalinization
WO1984004364A1 (en) * 1983-04-25 1984-11-08 Sundstrand Corp Fuel system bubble dissipation device
US4565488A (en) * 1983-10-21 1986-01-21 Accuspray, Inc. Compressor
US4704070A (en) * 1983-04-25 1987-11-03 Iseman Walter J Fuel system bubble dissipation device
US4767281A (en) * 1987-06-04 1988-08-30 Lear Siegler, Inc. Centrifugal pump system with inlet reservoir
US6098600A (en) * 1997-12-02 2000-08-08 Denso Corporation Fuel supply system
US20040197195A1 (en) * 2003-04-03 2004-10-07 Ogolla Beneah T. Combination water pump/air compressor system
US20100101655A1 (en) * 2008-10-27 2010-04-29 Gva Consultants Ab Ballast system
US20100104452A1 (en) * 2008-10-27 2010-04-29 Gva Consultants Ab Pump assembly
WO2010134882A1 (en) * 2009-05-19 2010-11-25 Gva Consultants Ab Tank arrangement adapted for a submersible pump
US20130284026A1 (en) * 2012-03-21 2013-10-31 Horizontal Rentals, Inc. Oil skimming apparatus and method for using same
CN109026746A (zh) * 2018-08-22 2018-12-18 陈明增 一种离心泵介质预储工艺

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2424472A1 (fr) * 1978-02-24 1979-11-23 Inst Francais Du Petrole Methode et dispositif pour transporter simultanement dans un meme conduit les constituants d'un fluide diphasique
FR2424473A1 (fr) * 1978-02-24 1979-11-23 Inst Francais Du Petrole Methode et dispositif pour acheminer dans un conduit un fluide diphasique a teneur en gaz libre elevee
FR2642539B1 (fr) * 1989-02-02 1995-12-08 Inst Francais Du Petrole Dispositif de regulation et d'amortissement d'un ecoulement polyphasique et son application
EP0549440B1 (fr) * 1991-12-27 1996-10-16 Institut Français du Pétrole Procédé d'optimisation d'un dispositif de régulation et d'amortissement d'un écoulement polyphasique et dispositif obtenu par le procédé
FR2694823B1 (fr) * 1992-08-11 1994-09-16 Inst Francais Du Petrole Procédé d'optimisation d'un dispositif de régulation et d'amortissement d'un écoulement polyphasique et dispositif obtenu par le procédé.

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2223112A (en) * 1938-10-26 1940-11-26 Martin & Schwartz Inc Apparatus for pumping and separating gas and liquid bodies
US2452421A (en) * 1945-09-29 1948-10-26 Charles F Ames Vacuum return pumping unit
US2651259A (en) * 1949-05-20 1953-09-08 Alanson P Brush Apparatus for controlling the operation of domestic water systems
US3490376A (en) * 1968-12-30 1970-01-20 Joe M Valdespino Well point system
US3619084A (en) * 1970-08-03 1971-11-09 Harold L Gordon Water supply and pump for fountains

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2223112A (en) * 1938-10-26 1940-11-26 Martin & Schwartz Inc Apparatus for pumping and separating gas and liquid bodies
US2452421A (en) * 1945-09-29 1948-10-26 Charles F Ames Vacuum return pumping unit
US2651259A (en) * 1949-05-20 1953-09-08 Alanson P Brush Apparatus for controlling the operation of domestic water systems
US3490376A (en) * 1968-12-30 1970-01-20 Joe M Valdespino Well point system
US3619084A (en) * 1970-08-03 1971-11-09 Harold L Gordon Water supply and pump for fountains

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4147474A (en) * 1976-12-28 1979-04-03 Norsk Hydro A.S Method and system for transferring liquid media
US4249864A (en) * 1978-06-19 1981-02-10 Auscoteng Pty. Ltd. Centrifugal pump system for water desalinization
WO1984004364A1 (en) * 1983-04-25 1984-11-08 Sundstrand Corp Fuel system bubble dissipation device
US4704070A (en) * 1983-04-25 1987-11-03 Iseman Walter J Fuel system bubble dissipation device
US4565488A (en) * 1983-10-21 1986-01-21 Accuspray, Inc. Compressor
US4767281A (en) * 1987-06-04 1988-08-30 Lear Siegler, Inc. Centrifugal pump system with inlet reservoir
US6098600A (en) * 1997-12-02 2000-08-08 Denso Corporation Fuel supply system
US20040197195A1 (en) * 2003-04-03 2004-10-07 Ogolla Beneah T. Combination water pump/air compressor system
US6942463B2 (en) * 2003-04-03 2005-09-13 Beneah T. Ogolla Combination water pump/air compressor system
US20100104452A1 (en) * 2008-10-27 2010-04-29 Gva Consultants Ab Pump assembly
US20100101655A1 (en) * 2008-10-27 2010-04-29 Gva Consultants Ab Ballast system
US8491273B2 (en) * 2008-10-27 2013-07-23 Gva Consultants Ab Ballast system
WO2010134882A1 (en) * 2009-05-19 2010-11-25 Gva Consultants Ab Tank arrangement adapted for a submersible pump
US20110126749A1 (en) * 2009-05-19 2011-06-02 Gva Consultants Ab Tank arrangement adapted for a submersible pump
EP2432681A1 (en) * 2009-05-19 2012-03-28 GVA Consultants AB Tank arrangement adapted for a submersible pump
CN102458976A (zh) * 2009-05-19 2012-05-16 Gva咨询股份公司 适用于潜水泵的储箱结构
US8739722B2 (en) 2009-05-19 2014-06-03 Gva Consultants Ab Tank arrangement adapted for a submersible pump
EP2432681A4 (en) * 2009-05-19 2014-08-20 Gva Consultants Ab TANK ASSEMBLY CONFIGURATED FOR A DIVING PUMP
CN102458976B (zh) * 2009-05-19 2015-03-25 Gva咨询股份公司 适用于潜水泵的储箱结构
US20130284026A1 (en) * 2012-03-21 2013-10-31 Horizontal Rentals, Inc. Oil skimming apparatus and method for using same
CN109026746A (zh) * 2018-08-22 2018-12-18 陈明增 一种离心泵介质预储工艺
CN109026746B (zh) * 2018-08-22 2020-07-28 陈明增 一种离心泵介质预储工艺

Also Published As

Publication number Publication date
GB1412215A (en) 1975-10-29
DE2301012A1 (de) 1973-07-19
FR2168111A1 (ja) 1973-08-24
SE366702B (ja) 1974-05-06
NL7300424A (ja) 1973-07-16
IT976778B (it) 1974-09-10
JPS4880466A (ja) 1973-10-27
ES410515A1 (es) 1976-05-01

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