US2985305A - Separation of liquids - Google Patents

Separation of liquids Download PDF

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Publication number
US2985305A
US2985305A US673387A US67338757A US2985305A US 2985305 A US2985305 A US 2985305A US 673387 A US673387 A US 673387A US 67338757 A US67338757 A US 67338757A US 2985305 A US2985305 A US 2985305A
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United States
Prior art keywords
interface
liquid
separator
emulsion
nitroglycerine
Prior art date
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Expired - Lifetime
Application number
US673387A
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English (en)
Inventor
Nock William
Prentice Thomas Robert
Bentley Roy
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.)
Imperial Chemical Industries Ltd
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Imperial Chemical Industries Ltd
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Filing date
Publication date
Application filed by Imperial Chemical Industries Ltd filed Critical Imperial Chemical Industries Ltd
Application granted granted Critical
Publication of US2985305A publication Critical patent/US2985305A/en
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D17/00—Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion
    • B01D17/02—Separation of non-miscible liquids
    • B01D17/0208—Separation of non-miscible liquids by sedimentation
    • B01D17/0214—Separation of non-miscible liquids by sedimentation with removal of one of the phases

Definitions

  • This invention relates to manufacturing processes which include the step of separating at least two liquids of different density and different electrical conductivity and more particularly in a continuous process for the manufacture of a liquid explosivenitric ester to the step of separating said ester from the spent nitrating acid mixture.
  • a separator for instance may be continuously fed with an emulsion of nitroglycerine in a mixture of nitric acid and sulphuric acid and as the nitroglycerine separates and rises and the mixed acid sinks three layers are formed, namely one of nitroglycerine, one of mixed nitric and sulphuric acids, and one of an emulsion of nitroglycerine in the mixed acids sandwiched between said layers. It is usual continuously to admit the said emulsion from a nitrator to the separator at a point intermediate between the top and the bottom and continuously to withdraw nitroglycerine from near the top of the separator and refuse acid from near the bottom.
  • the object of the present invention is to provide a process which permits the position of an interface between adjacent liquid layers which are formed when a mixture of liquids of different density and different electrical conductivity is separated in a separator to be kept within a stipulated range from a predetermined position more conveniently than heretofore and to provide apparatus therefor to permit said process to be carried out a distance from the separator either automatically or by visual or aural indication for manual operation.
  • the method which permits keeping within a stipulated range from a given position an interface between adjacent liquid layers which are formed when a mixture of liquids of different density and different electrical conductivity is separated in a separator comprises applying a difference of potential to the liquid at a predetermined position, detecting any changes in electrical conductivity of the liquid at said predetermined position, and arranging that the separation is carried out so that the electrical conductivity at said predetermined position is kept within predetermined values.
  • the method of the invention is particularly applicable United States Patent O "ice 2,985,305 Patented May 23, 19ti1 2 to a mixture of two liquids of different density and different electrical conductivity as for example an emulsion 'of nitroglycerine and spent nitrating acid.
  • An interface between adjacent liquid layers can be kept between a stipulated range from a given position 'for example simply by applying a difference of potential
  • an interface between adjacent liquid layers can be kept between a stipulated range from a given position by applying differences of potential to the liquid at at least two predetermined positions, detecting any changes in electrical conductivity of the liquid at said two predetermined positions, and arranging that the separation is carried out so that the electrical conductivity at each of said two predetermined positions is kept within predetermined values.
  • an emulsion of two liquids e.g. an emulsion of nitroglycerine and spent nitrating acid
  • a separator three liquid layers namely a layer of the emulsion and a layer for each of the two liquids wherein for instance there is an interface between the layer of the less dense liquid and the layer of emulsion and an interface between the layer of emulsion and the layer of the liquid of higher density
  • said separator is a static separator and if said two liquids are nitroglycerine and a spent nitrating acid in the form of an emulsion then said difference of potential is preferably a difference of alternating potential of a frequency preferably of at least 2 kc./s. and of such voltage that the electrical current is preferably less than 1 ma.
  • said difference of alternating potential should be applied to stainless steel electrodes and with such electrodes it has been found that alternating currents of 130 ma. can be passed through an agitated mixture of nitroglycerine and a mixture of nitric and sulphuric acids for half an hour without producing any significant change in the stability of the nitroglycerine.
  • the separator is of electrically conducting material and is a static separator it can conveniently -'be one of the electrodes.
  • a pair of electrodes can be situated in more than one predetermined position. If the separator consists of electrically conducting material then it can be one of the electrodes of each pair of electrodes and each of a the other electrodes required to form the pairs of elecposed stainless steel rings bonded thereto with their leading wires embedded axially in the polythene.
  • any change in conductivity between any particular pair or electrodes to which a difference of potential is applied as will for example be caused by the movement of an interface past at least one of the electrodes forming said pair may be detected in any known manner as for instance by an electrical bridge network containing a voltage detector working in association with an indicator or control unit.
  • the voltage detector may be of any conventional kind or preferably may be a phase sensitive detector comprising a gas-filled tetrode valve which has an alternating voltage of the same frequency as and preferably derived from the electrical source supplying the pair of electrodes applied to its screen grid, the control grid being supplied by an amplified output voltage from the bridge network.
  • the bride network can be so adjusted that when an interface passes the pair of electrodes such a change is caused in the current flowing in the bridge network that the alternating control grid voltage is brought into such :a phase relationship with the alternating screen grid voltage that the gas-filled tetrode valve is made conducting.
  • the method of the invention can be applied to any form of separator for separating a mixture of liquids'into'liquid layers as for instance a static separator or a centrifugal separator.
  • Figure 1 is an elevation of a continuous earthed stainless steel separator of the kind used in the manufacture of nitroglycerine provided with a set of seven single electrodes
  • Figure 2 is an electrical diagram illustrating in some detail one of seven electrical bridge networks and its detector and a set of signal lamps six of which are each operated by its detector and two of which are operated by the remaining seventh detector.
  • 1 is an earthed stainless steel continuous separator having a glass top portion 2
  • 3 is a tangentially positioned delivery pipe
  • 4 is a sight glass
  • 5 is a valve
  • 6 is a motor which controls the valve 5
  • 7 and 8 are relays which are controlled from a distance to operate the motor 6
  • 9 is an overflow pipe.
  • 10 is a layer of an emulsion of nitroglycerine and spent nitrating acid
  • 11 is a layer of nitroglycerine
  • 12 is a layer of spent nitrating acid.
  • 13 is the top interface
  • 14 is the bottom interface.
  • 15 is a set of seven single stainless steel electrodes 16, 17, 18, 19, 20, 21, 22 with their respective leading wires 23, 24, 25, 26, 27, 28, 29 which are connected to their respective screened cables 30, 31, 32, 33, 34, 35, 36.
  • the set 15 of the seven single stainless steel electrodes is shown so immersed in the three layers 10, 11 and 12 that the single electrodes 19 and 20 are on either side of the given position for the top interface 13. If the top 7 interface 13 rises or falls beyond the position of the electrodes 19 and 20 the necessary correction is made by varying the rate of withdrawal ofthe spent nitrating acid 12 through valve 5. If valve 5 has not been opened sufiicient- 1y when'the top interface 13 is rising this will be indicated by indicating means for electrode 18 and if the top interface 13 falls too rapidly this will be indicated by indicating means for electrode 21 when it becomes necessary to adjust valve 5 to diminish the rate of withdrawal of the 2 spent acid 12.
  • valve 5 When it is desired to remove all of the nitroglycerine layer 11 from'the separator 1 the valve 5 is closed while the emulsion of nitroglycerine and spent nitrating acid is introduced through pipe 3.
  • the top interface 13 begins to rise and this is indicated in due course by indicating meansfor the electrode 17 when the delivery ofsaid emulsion is discontinued.
  • the top interface 13 rises gradually .and when the indicating means for electrode 16 indicates thatitheilayer ofemulsion 10 has reached the given posi- .-.tion:fr.electrode 16 valve isimmediately opened so that 4 no emulsion is permitted to flow into the overflow pipe 9.
  • each of the seven electrical bridge networks is made up of resistors 37 and 38, a variable resistor 39 and a capacitor 40.
  • an alternating voltage at a frequency of 5 kc./ sec. is applied at terminals 41 and 42 'to supply this bridge network through an isolating screened transformer 43 and limiting resistors 44 and 45.
  • the output voltage from this bridge network is fed through the screened cable 46 to the amplifying valve 47 and after amplification to the control grid 48 of the gas-filled tetrode 49.
  • terminal 50 is also applied to terminal 50 and thereby to the screen grid ,51 in the gas-filled tetrode -49.
  • 52 is a terminal to which a source of direct voltage is applied for energising the amplifying valve 47.
  • '53 is a terminal to which a source of alternating voltage at a frequency of 50 cycles/ sec. is applied to energise the gas-filled tetrode 49.
  • 54 is a terminal to which a negative bias voltage is applied.
  • relay 58 associated with the next bridge network is energised to close contact 59 and to light signal lamp 60.
  • relay 61 associated with the third bridge network is energised to close contact 62 and to light signal lamp 63.
  • the top interface 13 passes the electrode ,19 relay 64 associated with the fourth bridge network, connected and to which an alternating voltage is applied as 'in the first bridge network, is energised to close contact 65 and .to light signal lamp 66.
  • top interface 13 passes the electrode 20 associated with the fifth bridge network, connected and to which an alternating voltage is applied as in the first bridge network, 18:611- ergised to close contact 68 and to light signal lamp 69.
  • electrode 21 relay 70 associated with the sixth bridge network connected and to which an alternating voltage is applied as in the first bridge network, is energised to close contact 71 and to light signal lamp 72.
  • the position of the top interface 13 is known to be above the position of the electrode corresponding to the topmost lit signal lamp.
  • relay 73 associated with the seventh bridge network connected and to which an alternating voltage is applied as in the first bridge network, is unenergised and lamp 74' is lit through contact 75.
  • the relay 73 is energised and changes over the contact 75 to light signal lamp 76.
  • the signal lamp 66 when the signal lamp 66 is lit indicating that the top interface 13 is above the given position for the electrode 19 valve 5 may be opened by an operator working by remote control the relays 7 and 8 to keep said top interface 13 within its stipulated range.
  • a method which comprises applying at a predetermined position in a separator to the liquid therein, which includes a liquid explosive nitric ester/nitrating acid mixture, an alternating potential difference such as to pass through said liquid in its emulsion condition an alternating current not exceeding 130 milliamps at a frequency of at least two kilocycles per second, detecting any changes in electrical conductivity of the liquid at said predetermined position, and causing in response to the detection of such changes separation of the mixture to be carried out so that the electrical conductivity of the liquid at said predetermined position is kept within predetermined values.

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  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
US673387A 1956-08-13 1957-07-22 Separation of liquids Expired - Lifetime US2985305A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB24682/56A GB820963A (en) 1956-08-13 1956-08-13 Improvements in or relating to the separation of liquids

Publications (1)

Publication Number Publication Date
US2985305A true US2985305A (en) 1961-05-23

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ID=10215617

Family Applications (1)

Application Number Title Priority Date Filing Date
US673387A Expired - Lifetime US2985305A (en) 1956-08-13 1957-07-22 Separation of liquids

Country Status (5)

Country Link
US (1) US2985305A (fr)
BE (1) BE560041A (fr)
CH (1) CH368142A (fr)
FR (1) FR1181166A (fr)
GB (1) GB820963A (fr)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3189268A (en) * 1961-12-22 1965-06-15 Ab Device for determining the position of the interface between two separated components in a centrifugal separator
US3231090A (en) * 1961-05-17 1966-01-25 Technicon Instr Continuous solvent extraction apparatus
US3450984A (en) * 1965-10-21 1969-06-17 Avco Corp Method and apparatus for measuring the flow velocity of an electrolytic fluid by electrolysis
US3471393A (en) * 1966-04-04 1969-10-07 Int Paper Canada Apparatus for testing liquids utilizing plurality of probes or electrodes with sensitive ends converging in liquid flow path
US3519400A (en) * 1967-01-25 1970-07-07 Atomic Energy Commission Method of centrifugal separation and recovery of chemical species utilizing a liquid medium
US3682305A (en) * 1970-02-20 1972-08-08 Joseph Buchler Decanting and filling apparatus
US4120786A (en) * 1977-03-29 1978-10-17 General Electric Company Separation of mixed ion exchange resins
US5431826A (en) * 1993-03-19 1995-07-11 Zurn Industries, Inc. Automatic grease interceptor with temperature and grease level monitoring
US20040035784A1 (en) * 2002-08-21 2004-02-26 Kozak Andrew F. System and method for separating immiscible fluids
US20070095765A1 (en) * 2005-10-28 2007-05-03 Kozak Andrew F Iii Liquid purification system and method for purifying a liquid using liquid-to-liquid heating and cooling
US20080237107A1 (en) * 2007-03-29 2008-10-02 Aquitic Technology, Inc. Desalinization system and method
US9279420B2 (en) 2013-05-31 2016-03-08 Intellectual Property Holdings, Llc Natural gas compressor

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1983002824A1 (fr) * 1982-02-12 1983-08-18 Dranmont Pty Ltd Systeme de detection et de controle du niveau d'un fluide
GB8412460D0 (en) * 1984-05-16 1984-06-20 Schlumberger Electronics Uk Fluid level measurement
WO1986007158A1 (fr) * 1985-05-20 1986-12-04 Fts Systems, Inc. Appareils et procedes pour faire subir un vieillissement accelere a des dispositifs a semi-conducteurs
US4745354A (en) * 1985-05-20 1988-05-17 Fts Systems, Inc. Apparatus and methods for effecting a burn-in procedure on semiconductor devices

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1503956A (en) * 1922-05-19 1924-08-05 Hercules Powder Co Ltd Explosive and process of making same
US1577981A (en) * 1924-02-14 1926-03-23 Nl Tech Handel Mij Giro Resistance element
US2140897A (en) * 1935-10-21 1938-12-20 Ici Ltd Manufacture of explosives
US2523253A (en) * 1945-09-10 1950-09-19 Harshaw Chem Corp Electrodeposition anode
US2831579A (en) * 1954-11-03 1958-04-22 Gale Separator Co Inc Apparatus for removing oil from oil and water mixtures

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1503956A (en) * 1922-05-19 1924-08-05 Hercules Powder Co Ltd Explosive and process of making same
US1577981A (en) * 1924-02-14 1926-03-23 Nl Tech Handel Mij Giro Resistance element
US2140897A (en) * 1935-10-21 1938-12-20 Ici Ltd Manufacture of explosives
US2523253A (en) * 1945-09-10 1950-09-19 Harshaw Chem Corp Electrodeposition anode
US2831579A (en) * 1954-11-03 1958-04-22 Gale Separator Co Inc Apparatus for removing oil from oil and water mixtures

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3231090A (en) * 1961-05-17 1966-01-25 Technicon Instr Continuous solvent extraction apparatus
US3189268A (en) * 1961-12-22 1965-06-15 Ab Device for determining the position of the interface between two separated components in a centrifugal separator
US3450984A (en) * 1965-10-21 1969-06-17 Avco Corp Method and apparatus for measuring the flow velocity of an electrolytic fluid by electrolysis
US3471393A (en) * 1966-04-04 1969-10-07 Int Paper Canada Apparatus for testing liquids utilizing plurality of probes or electrodes with sensitive ends converging in liquid flow path
US3519400A (en) * 1967-01-25 1970-07-07 Atomic Energy Commission Method of centrifugal separation and recovery of chemical species utilizing a liquid medium
US3682305A (en) * 1970-02-20 1972-08-08 Joseph Buchler Decanting and filling apparatus
US4120786A (en) * 1977-03-29 1978-10-17 General Electric Company Separation of mixed ion exchange resins
US5431826A (en) * 1993-03-19 1995-07-11 Zurn Industries, Inc. Automatic grease interceptor with temperature and grease level monitoring
US20040035784A1 (en) * 2002-08-21 2004-02-26 Kozak Andrew F. System and method for separating immiscible fluids
US6919034B2 (en) * 2002-08-21 2005-07-19 Apartar Technologies Inc. System and method for separating immiscible fluids
US20070095765A1 (en) * 2005-10-28 2007-05-03 Kozak Andrew F Iii Liquid purification system and method for purifying a liquid using liquid-to-liquid heating and cooling
US20080237107A1 (en) * 2007-03-29 2008-10-02 Aquitic Technology, Inc. Desalinization system and method
US7470873B2 (en) 2007-03-29 2008-12-30 Aquitic Technology, Inc. Desalinization system and method
US9279420B2 (en) 2013-05-31 2016-03-08 Intellectual Property Holdings, Llc Natural gas compressor

Also Published As

Publication number Publication date
BE560041A (fr)
CH368142A (de) 1963-03-31
GB820963A (en) 1959-09-30
FR1181166A (fr) 1959-06-12

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