US2983107A - Vaporisation of liquefied gases - Google Patents

Vaporisation of liquefied gases Download PDF

Info

Publication number
US2983107A
US2983107A US843091A US84309159A US2983107A US 2983107 A US2983107 A US 2983107A US 843091 A US843091 A US 843091A US 84309159 A US84309159 A US 84309159A US 2983107 A US2983107 A US 2983107A
Authority
US
United States
Prior art keywords
vaporiser
pressure
tube
vaporisation
packing
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
US843091A
Inventor
Forrest John
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.)
BOC Group Ltd
Original Assignee
British Oxigen Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by British Oxigen Ltd filed Critical British Oxigen Ltd
Application granted granted Critical
Publication of US2983107A publication Critical patent/US2983107A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • 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
    • F17C9/00—Methods or apparatus for discharging liquefied or solidified gases from vessels not under pressure
    • F17C9/02—Methods or apparatus for discharging liquefied or solidified gases from vessels not under pressure with change of state, e.g. vaporisation

Definitions

  • VAPORISATION OF LIQUEFIED GASES Filed Sept. 29, 1959
  • liquefied gases of low boiling point is meant liquefied gases boiling at 1 atmosphere pressure at temperatures below ambient and particularly below --l50 C.
  • liquefied gases are liquid oxygen, liquid nitrogen and liquid methane.
  • a widely used method of vaporising liquefied gases of low boiling point and superheating the gas so formed to atmospheric temperature consists in passing the liquefied gas through a tubular vaporiser in heat exchange relationship with a warm fluid surrounding the tubes.
  • the tubes are usually mounted with their axes vertical, the liquefied gas being pumped to the lower end of the tubes and gas superheated to atmospheric temperature being withdrawn from the top of the tubes.
  • a method of reducing pressure surging during the vaporisation and superheating of liquefied gases of low boiling point as hereinbefore defined by heat exchange with a fluid whose temperature is substantially higher than that of said liquefied gas in a tube type vaporiser comprises packing the section of the tube or tubes in which evaporation of the liquefied gas takm place with randomly disposed packing elements.
  • a tube type vaporiser for the vaporisation and superheating of liquefied gases of low boiling point as hereinbefore defined by heat exchange with a fluid whose temperature is substantially higher than that of said liquefied gas and having a reduced tendency to pressure surging in use has the section thereof in which evaporation of the liquefied gas takes place packed with randomly disposed packing elements.
  • This increase may be as much as metal.
  • the packing elements may be any of the well-known elements used for the random packing of gas liquid contact devices, for example, Raschig rings or McMahan saddles.
  • the packing elements are preferably made of Their size will depend on the diameterof the vaporiser tube. Thus for a tube of diameter 2 inches, Raschig'rings of 4 inch diameter are a suitable packing.
  • the density of packing is preferably at least 60% by which is meant that the actual number of rings used are about 60% of the maximum number which it is possible to contain in the tube when randomly packed and tamped down.
  • the packing promotes turbulence in the .vaporising section of the vaporiser and reduces spasmodic ebullition. Fluctuations of the pump delivery pressure and the temperature of the gas leaving the vaporiser are substantially reduced and there is a considerable reduction in noise and vibration from the tube or tubes and the associated piping.
  • the flow through the packed vaporiser is very smooth and itsoutputiis appreciably increased.
  • the precise length of the tube which requires to be packed in accordance with the present invention will depend on the diameter of the tube, the pressure and throughput of liquefied gas and the particular liquefied gas being vapon'sed.
  • the surface area of the packed section will be approximately 0.53 sq. ft. per 10,000 s.ft. per hour of oxygen evaporated.
  • the corresponding figures are 0.43 and 0.68 respectively.
  • the evaporating section should be substantially completely packed, since if only a part of this section is packed, pressure surging will still take place.
  • the packing was /1 inch Raschig rings. With a packed section of length 4 ft. at 70% packing density and a pump suction pressure of 9v p.s.i.g., the pump delivered pressure was 40 p.s.i.g. fluctuating i5 p.s.i.g. with peaks of 50 p.s.i.g.
  • the term perature of gaseous oxygen leaving the vaporiser was 20 C. :20 C. and was diflicult to control.
  • the output of the vaporiser was 59,000 s.ft. /hr. of oxygen.
  • the pump delivery pressure was steady at 40 p.s.i.g. and the temperature of the oxygen leaving the vaporiser was steady at 20 C.
  • the output was 62,500 s.ft. /l1r.
  • Packing of the vaporiser beyond the evaporating section does not further reduce pressure surging but it increases the pressure drop through the vaporiser and this may cause a substantial drop in throughput.
  • FIG. 1 shows diagrammatically a circuit for the vaporisation of a liquefied gas incorporating a vaporiser according to the present invention
  • Figure 2 shows diagrammatically a part of the vaporiser of Figure 1 in more detail.
  • the liquefied gas is stored within a' thermally insulated vessel 10 from the bottom of which it passes through a line 11 to a pump 12 where it is pumped to any desired pressure below the critical pressure of the gas.
  • the liquefied gas is then passed by line 13 to an evaporater and superheater consisting of a single tube 14 wound in a helix through which the liquefied gas is passed, enclosed in a vessel 15, through which a heatproviding fluid such as steam is passed by means of an inlet 16 and an outlet 17.
  • a heatproviding fluid such as steam
  • the tube 14 is shown diagrammatically in greater detail in Figure 2.
  • the liquefied gas enters at a bottom inlet retaining devices 22, 23 in the form of perforated cone- 7 Y shaped metal plates located at each end of the vaporisation section.
  • the tsuperheating section comprises the remainder of the tube 14, the upper retaining device 23 being located at the point along the tube '14 where evaporation of the liquid is complete.
  • a method of reducing pressure surging during the vaporisation and superheating of a liquefied gas of low boiling point by heat exchange with a fluid whose temperature is substantially higher than that of said liquefied gas in a tube-type combined vaporiser and'superheater comprising packing only thattsection of the tube or tubes in which evaporation of the liquefied gas takes place to a packing density of at least 60% with randomly-disposed, hollow, geometrically-shaped, metal packing elements of the type used for randomly packing gas/liquid contact devices.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Oxygen, Ozone, And Oxides In General (AREA)
  • Filling Or Discharging Of Gas Storage Vessels (AREA)
  • Separation By Low-Temperature Treatments (AREA)

Description

y 1961 I J. FORREST 2,983,107
VAPORISATION OF LIQUEFIED GASES Filed Sept. 29, 1959 Inventor T HN FORREST ttorney United see aw r' f I Patented M 1 1 7 2,983,101 VVAPORISATION F LIQUEFIED GASES lohn Forrest, Cockfosters, England, assignor to The British Oxygen Company Limited, a company of Great Britain 'I'hisiinventionrelates to the vaporisation of liquefied gases of low boiling point and more particularlyto a method ofreducing, pressure surging" in tube type vaporisers for the 'vaporisation anglsuperheating of suchliquefiedgases.
By the term liquefied gases of low boiling point" is meant liquefied gases boiling at 1 atmosphere pressure at temperatures below ambient and particularly below --l50 C. Examples of such liquefied gases are liquid oxygen, liquid nitrogen and liquid methane.
A widely used method of vaporising liquefied gases of low boiling point and superheating the gas so formed to atmospheric temperature consists in passing the liquefied gas through a tubular vaporiser in heat exchange relationship with a warm fluid surrounding the tubes. The tubes are usually mounted with their axes vertical, the liquefied gas being pumped to the lower end of the tubes and gas superheated to atmospheric temperature being withdrawn from the top of the tubes.
It is known that in tubular vaporisers, when the tube diameter is increased beyond a certain limit, the phenomenon known as pressure surging occurs. It is not possible, at economic flow rates to avoid the surging under such conditions. Pressure surging, that is to say ebullition in the vaporiser, is spasmodic and the pump delivery pressure and the temperature of the vaporised gas leaving the vaporiser both fluctuate violently. The phenomenon also produces considerable noise and vibration of the vaporising coil and its connecting pipework. Alternative methods of avoiding pressure surging would be to use an increased number of tubes with reduced diameters, or to raise the pressure of the liquefied gas above the critical pressure of the fluid followed by a reduction in such pressure after evaporation. Both alternatives have obvious disadvantages.
It is an object of the present invention to provide a method of reducing pressure surging in such vaporisers.
It is a further object to provide a vapcriser of this type in which pressure surging does not substantially occur in use.
According to one aspect of the present invention, a method of reducing pressure surging during the vaporisation and superheating of liquefied gases of low boiling point as hereinbefore defined by heat exchange with a fluid whose temperature is substantially higher than that of said liquefied gas in a tube type vaporiser, comprises packing the section of the tube or tubes in which evaporation of the liquefied gas takm place with randomly disposed packing elements.
According to another aspect of the present invention, a tube type vaporiser for the vaporisation and superheating of liquefied gases of low boiling point as hereinbefore defined by heat exchange with a fluid whose temperature is substantially higher than that of said liquefied gas and having a reduced tendency to pressure surging in use has the section thereof in which evaporation of the liquefied gas takes place packed with randomly disposed packing elements.
This increase may be as much as metal.
The packing elements may be any of the well-known elements used for the random packing of gas liquid contact devices, for example, Raschig rings or McMahan saddles. The packing elements are preferably made of Their size will depend on the diameterof the vaporiser tube. Thus for a tube of diameter 2 inches, Raschig'rings of 4 inch diameter are a suitable packing. The density of packing is preferably at least 60% by which is meant that the actual number of rings used are about 60% of the maximum number which it is possible to contain in the tube when randomly packed and tamped down.
The packing promotes turbulence in the .vaporising section of the vaporiser and reduces spasmodic ebullition. Fluctuations of the pump delivery pressure and the temperature of the gas leaving the vaporiser are substantially reduced and there is a considerable reduction in noise and vibration from the tube or tubes and the associated piping. The flow through the packed vaporiser is very smooth and itsoutputiis appreciably increased.
"The precise length of the tube which requires to be packed in accordance with the present invention will depend on the diameter of the tube, the pressure and throughput of liquefied gas and the particular liquefied gas being vapon'sed. Thus, for liquid oxygen at a pressure of 30 p.s.i.g. and using steam at 40 p.i.s.g. for heating, then the surface area of the packed section will be approximately 0.53 sq. ft. per 10,000 s.ft. per hour of oxygen evaporated. For liquid nitrogen and liquid methane, the corresponding figures are 0.43 and 0.68 respectively.
It is essential in packing the vaporiser in accordance With the present invention that the evaporating section should be substantially completely packed, since if only a part of this section is packed, pressure surging will still take place. To illustrate this, experiments were made with a single tube vaporiser for liquid oxygen under conditions such that the length of'the evaporating section was between 4 and 6 feet. The packing was /1 inch Raschig rings. With a packed section of length 4 ft. at 70% packing density and a pump suction pressure of 9v p.s.i.g., the pump delivered pressure was 40 p.s.i.g. fluctuating i5 p.s.i.g. with peaks of 50 p.s.i.g. The term perature of gaseous oxygen leaving the vaporiser was 20 C. :20 C. and was diflicult to control. The output of the vaporiser was 59,000 s.ft. /hr. of oxygen.
With the vaporiser packed for a length of 6 ft. at 63% packing density, the pump delivery pressure was steady at 40 p.s.i.g. and the temperature of the oxygen leaving the vaporiser was steady at 20 C. The output was 62,500 s.ft. /l1r.
Packing of the vaporiser beyond the evaporating section does not further reduce pressure surging but it increases the pressure drop through the vaporiser and this may cause a substantial drop in throughput.
The invention will now be described with reference to the accompanying drawings in which Figure 1 shows diagrammatically a circuit for the vaporisation of a liquefied gas incorporating a vaporiser according to the present invention; and
Figure 2 shows diagrammatically a part of the vaporiser of Figure 1 in more detail.
Referring to Figure l, the liquefied gas is stored within a' thermally insulated vessel 10 from the bottom of which it passes through a line 11 to a pump 12 where it is pumped to any desired pressure below the critical pressure of the gas. The liquefied gas is then passed by line 13 to an evaporater and superheater consisting of a single tube 14 wound in a helix through which the liquefied gas is passed, enclosed in a vessel 15, through which a heatproviding fluid such as steam is passed by means of an inlet 16 and an outlet 17. In the tube 14, the liquefied gas is first evaporated and the vapour so formed superheated by heat exchange with the heat-providing fluid,
1 the superheated vapour leaving by a line 18.
The tube 14 is shown diagrammatically in greater detail in Figure 2. The liquefied gas enters at a bottom inlet retaining devices 22, 23 in the form of perforated cone- 7 Y shaped metal plates located at each end of the vaporisation section. The tsuperheating section comprises the remainder of the tube 14, the upper retaining device 23 being located at the point along the tube '14 where evaporation of the liquid is complete.
'Iclaimx 1. A method of reducing pressure surging during the vaporisation and superheating of a liquefied gas of low boiling point by heat exchange with a fluid whose temperature is substantially higher than that of said liquefied gas in a tube-type combined vaporiser and'superheater comprising packing only thattsection of the tube or tubes in which evaporation of the liquefied gas takes place to a packing density of at least 60% with randomly-disposed, hollow, geometrically-shaped, metal packing elements of the type used for randomly packing gas/liquid contact devices.
2. A tube-type combined vaporiser and superheater for the vaporisation and superheating of liquefied gases of low boiling point by heatiexchange with a fluid whose temperature. is substantially, higher than that of said liquefied gas having only that section of the tube or tubes thereof in which vaporisation of the liquefied gas takes .placepacked to a packing density of at least 60% with randomly disposed, hollow, geometricallyrshaped, metal packing elements of the type used for randomly packing gas/liquid contact devices, whereby pressure rgingisreduced durin a 7 References Gited in the file of this patent UNITED STATES PATENTS 2,565,221 6 Gaug1er Aug. 21, 1951
US843091A 1958-09-29 1959-09-29 Vaporisation of liquefied gases Expired - Lifetime US2983107A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB30993/58A GB862758A (en) 1958-09-29 1958-09-29 Vaporisation of liquefied gases

Publications (1)

Publication Number Publication Date
US2983107A true US2983107A (en) 1961-05-09

Family

ID=10316311

Family Applications (1)

Application Number Title Priority Date Filing Date
US843091A Expired - Lifetime US2983107A (en) 1958-09-29 1959-09-29 Vaporisation of liquefied gases

Country Status (2)

Country Link
US (1) US2983107A (en)
GB (1) GB862758A (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3195854A (en) * 1962-02-20 1965-07-20 Partlow Corp Valve for nitrogen cooling system
US4438729A (en) * 1980-03-31 1984-03-27 Halliburton Company Flameless nitrogen skid unit
US4458633A (en) * 1981-05-18 1984-07-10 Halliburton Company Flameless nitrogen skid unit
US5040380A (en) * 1988-08-04 1991-08-20 Super S.E.E.R. Systems Inc. Method and apparatus for the sensing of refrigerant temperatures and the control of refrigerant loading
US20190309495A1 (en) * 2018-04-06 2019-10-10 Linde Aktiengesellschaft Method for reducing noise emissions on ground freezing construction sites

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1677804A (en) * 1923-01-29 1928-07-17 Ubald R Loranger Gas scrubber for refrigerating apparatus
US1804836A (en) * 1924-06-16 1931-05-12 Automatic Freezer Corp Scrubber for refrigerating apparatus
US1823079A (en) * 1927-03-31 1931-09-15 Frigidaire Corp Refrigerating apparatus
US2350348A (en) * 1942-12-21 1944-06-06 Gen Motors Corp Heat transfer device
US2416924A (en) * 1943-02-27 1947-03-04 Green S Fuel Inc Method and means for producing ebullition in liquefied petroleum gases
US2565221A (en) * 1946-04-06 1951-08-21 Gen Motors Corp Refrigerating apparatus

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1677804A (en) * 1923-01-29 1928-07-17 Ubald R Loranger Gas scrubber for refrigerating apparatus
US1804836A (en) * 1924-06-16 1931-05-12 Automatic Freezer Corp Scrubber for refrigerating apparatus
US1823079A (en) * 1927-03-31 1931-09-15 Frigidaire Corp Refrigerating apparatus
US2350348A (en) * 1942-12-21 1944-06-06 Gen Motors Corp Heat transfer device
US2416924A (en) * 1943-02-27 1947-03-04 Green S Fuel Inc Method and means for producing ebullition in liquefied petroleum gases
US2565221A (en) * 1946-04-06 1951-08-21 Gen Motors Corp Refrigerating apparatus

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3195854A (en) * 1962-02-20 1965-07-20 Partlow Corp Valve for nitrogen cooling system
US4438729A (en) * 1980-03-31 1984-03-27 Halliburton Company Flameless nitrogen skid unit
US5551242A (en) * 1980-03-31 1996-09-03 Halliburton Company Flameless nitrogen skid unit
US4458633A (en) * 1981-05-18 1984-07-10 Halliburton Company Flameless nitrogen skid unit
US5040380A (en) * 1988-08-04 1991-08-20 Super S.E.E.R. Systems Inc. Method and apparatus for the sensing of refrigerant temperatures and the control of refrigerant loading
US20190309495A1 (en) * 2018-04-06 2019-10-10 Linde Aktiengesellschaft Method for reducing noise emissions on ground freezing construction sites

Also Published As

Publication number Publication date
GB862758A (en) 1961-03-15

Similar Documents

Publication Publication Date Title
US2576985A (en) Liquid oxygen converter
US3986340A (en) Method and apparatus for providing superheated gaseous fluid from a low temperature liquid supply
US3195316A (en) Methane liquefaction system
US4133184A (en) Method of flow stabilization in a tube and shell vaporizer
US2983107A (en) Vaporisation of liquefied gases
US2343727A (en) Vaporizing device
US3377813A (en) Storage container
JPH0727297A (en) Cryogen station for supplying cryogen substantially free from impurity of high boiling point
US2344765A (en) Method of and apparatus for storing liquefied gas mixtures
US2938360A (en) Anhydrous ammonia storage tank
US2665556A (en) Insulated bayonet tube vaporizer
US3371497A (en) Maintaining constant composition in a volatile multi-component liquid
EP3397912B1 (en) Method and heat exchanger for recovering cold during the re-gasification of cryogenic liquids
TWI220445B (en) Method and system for delivering a vapor component product to an end user from a storage system
US3260060A (en) Dewar for liquid air and/or other multicomponent cryogenic liquids
DE202015008836U1 (en) Heat exchanger for the recovery of cold during the regasification of cryogenic liquids
Sun et al. Research on the falling film flow and heat transfer characteristics of FLNG spiral wound heat exchanger under sea conditions
US3070968A (en) Liquid to gas conversion system
US3151467A (en) Process and apparatus for the filling, transportation and dispensing of hazardous fluids
US3360947A (en) Cryogenic phase separator
US2561506A (en) Liquefied gas evaporator
US2968163A (en) Apparatus for storing and dispensing liquefied gases
US3225552A (en) Revaporization of cryogenic liquids
US2915883A (en) Gas-fractionating column
US3306061A (en) Blowdown of cryogenic liquid supply vessel