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Патент USA US3023614

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March 6, 1962
M. c. BURK
3,023,605
CHROMATOGRAPHIC ANALYZER
Filed Aug. 19, 1957
CHROMATOGRAPHIC
COL U M N
52
99
L__l l" 5519?’?
55
90/19: saw/‘94196)?’
“1
.
FIG. 4
INVENTOR.
M. C. BU RK
BY Wm _
Unite States Patent
3,@23,605
Patented Mar. 6, 1962
1
2
3,023,605
passes through ports 1, 2 of the valve to a sample loop
15 which, in turn, is connected by valve ports 5, 6 to a
pressure regulator 16, an exhaust pump 17, and a suitable
CHROMATOGRAPHIC ANALYZER
Marvin C. Burk, Bartlesville, Okla., assignor to Phillips
Petroleum Company, a corporation of Delaware
vent, not shown.
Filed Aug. 19, 1957, Ser. No. 678,951
2 Claims. (Cl. 73-23)
a ?rst thermal conductivity cell 19 and, thence, through a
This invention relates to a chromatographic analyzer.
In chromatographic analyzers, a sample in the gas phase
is passed through a column containing sorptive material.
such as coconut charcoal. crushed ?re brick impregnated
with a silicone oil, or dimethyl sulfalone. molecular sieve
material, and the like. The least readily sorbed component
leaves the column ?rst, followed,hy the next least readily
sorbed components, in succession, with the result that 15
the sample is broken down into several components. The I
e?luent from the column is analyzed by determining its '
thermal conductivity.
Since the thermal conductivity of the various compo
.
A carrier gas, such as helium, passes from a line 18 to
line 20 and ports 3, 4 of the valve to the inlet of the col
umn 10. The outlet of the column 10 is connected
through a thermal conductivity cell 21 to a vent line 22.
With the valve in this ?rst position, therefore, the sample
passes through the loop 15 to vent, and carrier gas passes
through the column.
With the valve in its second position, the sample passes
through ports 1, 6 to the pressure regulator 16 and vent
while carrier gas passes through ports 4, 5 to the sample
loop and, thence, through ports 2, 3 to the column 10, thus
displacing the constant volume of sample trapped within
the loop when the valve was in its ?rst position.
The components appear in the column e?luent, in order
nents may vary, it is highly desirable or even essential to 20 of increasing sorbability, and thus unbalance a bridge
vary the sensitivity of the recording device in accordance
with the thermal conductivity of the particular component
under consideration and, more importantly. its concentra
tion. Also, in order to obtain volume reproducibility be
tween successive samples. a portion of the sample is
circuit 23 incorporating the thermal conductivity cells
19 and 21, the temperature of the incoming carrier gas
being compensated for by the inclusion of the cell 19 in
the bridge circuit. The bridge circuit further includes
trapped within a small chamber or sample loop, and this
tiometer 26. A direct potential is applied-between the
contactor of potentiometer 26 and ground at the junction
between the cells 19, 21 by a regulated direct current
power supply.
With a calibrating switch 30a, 30b in its upper posi-'
30
tion, as shown, the output of the bridge appears between
known volume of sample in the loop is thereafter dis
placed into the column by a carrier gas. This sequence
of operations can advantageously be controlled by an
oscillating valve movable to two positions by a reversible
motor.
In accordance with this invention, an improved disc
timer is provided to control the operation of the sample
valve and simultaneously to insert variable'impedances in
the recorder circuit so as to adjust the recorder sensitivity
for the particular component being analyu_d during a
?xed resistances 24, 25 connected in series with a poten~
leads 31 and 32, the lead 32 being connected to a recorder
input terminal 33a and to one ?xed contact of each of
a set 3411 to 340 of potentiometers, one such potentiometer
being provided for each component to be analyzed. The
other ?xed terminal of each potentiometer 34 is con
given period. The latter sequence of operations is con
trolled by detachable tabs at the edge of the disc which are
nected to a terminal of a bank 351: of a selector switch
35 while the contactors of these potentiomcters are con
placed to correspond to the time each particular com
nected to the respective contacts of a selector switch bank
ponent is present in the e?luent from the chromatographic 40 35b. The arm of contact bank 35b is connected through
column. The valve motor is controlled by another por
a normally closed contact set 36a of a relay 36 to another
tion of the disc, for example, by openings formed therein
recorder input terminal 33b while the arm of the bank 350
to pass a beam of light at desired times as the disc rotates.
is connected to the bridge output lead 31. The second
The resulting control impulses are fed to a transistor type
bank contacts are connected together by a lead 37 while
ampli?er which actuates suitable relay devices to carry
the ?rst and third contacts of bank 35b are connected by
on the aforementioned control functions.
a lead 38 to the lead 32.
\
Accordingly, it is an object of the invention to provide
an improved programming system for a chromatographic
With the switch 30 in its lower position, a calibrating
voltage appears between the leads 31, 32 by virtue of _a
It is a further object to provide a timing and program
?xed resistance 40a and a potentiometer 40b.
When the selector switch is in one of its lower three
positions, one of the potentiometers 34 is connected in
analyzer.
ming circuit which is simple. reliable in operation, and
utilizes a minimum number of circuit components.
circuit between the bridge output leads and the recorder
It is a still further object to insure provision of constant
sample volumes to a chromatographic column during suc
input terminals, thus varying the sensitivity of the recorder
input circuit in accordance with the particular component
of the sample which is being analyzed. When the switch
cessive analyses of samples of similar composition.
Various other objects, advantages and features of the
invention will become apparent from the following de
tailed description taken in conjunction with the accom
panying drawings in which:
is on its second bank contact, the bridge is connected
directly to the recorder input for zeroing or balancing
purposes. When the selector switch is in its ?rst or third
position. the recorder input terminals 33 are short-cir
FIGURE 1 is a schematic circuit diagram of the pro 60 cuited with the relay 36 die-energized and, whenever the
gramming circuit;
FIGURE 2 is a top view of the timing disc;
FIGURE 3 is a detail view illustrating the manner
in which tabs ?t upon the timing disc; and
FIGURE 4 is a drawing of a recording.
Referring now to FIGURE 1, the flow of sample and
carrier gas to a chromatographic column 10 is controlled
relay 36 is energized, the recorder input-terminals are
short-circuited by a lead 41. Finally, a calibrating voltage
can be produced from the bridge, at will, by movement
of the switch 30 to its lower position.
I‘
t
The recorder has a chart drive motor 42, one terminal
of which is neutral and the other terminal of which is
connected to’ the arm of a contact bank 35g and to a nor
by a rotary valve 11 which, in the example shown, is pro
mally open contact set 430 of a relay 43. An alternating
vided with six ports. This valve can be oscillated between
current source 44 is connected to the second contact of
two angular positions by a motor 12 connected to the
70 the bank 35g. Thus, the recorder motor is energized
valve by a friction clutch 13.
when the relay 43 is actuated or when the selector switch
In the ?rst valve‘ position, a sample from a line 14
is at its second contact posiuion.
3,028,606
The reversible valve motor 12 has two coils 12a and
12b, one terminal of each coil being connected to a volt
age source 45 through a normally open contact set 46a
of a relay 46. A lead 47 connects the other terminal of
the coil 12a to the ?rst contact of a bank 350' of the se
lector switch 35 and, similarly, the third contact of this
4
35 makes one step due to the energization of relay 43 and
the consequent closure of its contacts 43b. The selector
switch is reset each time an opening 60 passes between
the source 61 and cell 62 provided that the arm of the
contact bank 35,‘ dwells upon one of the three lower bank
contacts, this action occurring through the operation of
bank is connected by a lead 48 to the other terminal of
relay 46 and closure of its contacts 46b.
the coil 12b. A condenser 49 is connected across the leads
The overall operation of the system will now be de
47, 48. The arm of the contact hank 35d is connected to
scribed, assuming that the parts are in a position where
a voltage source 50, and each of the other bank contacts 10 the opening 600 is passing between the lamp 61 and cell
is connected through one of a series 51a to 51d of in
62, thus energizing relays 36 and 46. Therefore, the re
dicator lamps to neutral.
Accordingly, with the selector switch in its ?rst position,
the motor 12 is rotated in one direction to move the
valve to its ?rst position where sample passes through
the loop 15 and carrier gas passes through the column 10,
the clutch ‘13 permitting the motor to turn after the valve
has reached its end position. When the arm of the bank
35d dwells on the third contact, the motor 12 is rotated
in the opposite direction to move the valve 11 to its sec~
ond position, both of these movements being controlled
by the relay 46.
In accordance with the invention, the operation of the
foregoing units is controlled by a novel disc timing device.
This device incorporates a disc 52, FIGURES 1 and 2,
?xed to the shaft of a motor 53 which is energized from
an alternating current source 54 under the control of a
switch 55. Detachably secured to the edge of the disc
corder input terminals are short-circuited, and the chart
motor is stopped because no tab- is between the cell 57v
and the source 56. This is the point 90 on the recording,
FIGURE 4. This causes the selector switch to reset with
the result that the bank arms move to their ?rst position.
Relay 36 short-circuits the recorder input terminals while
relay 46 causes the motor 12 to move the valve 11 to its
?rst position where the incoming sample ?ows through
the loop 15 to vent and the carrier gas passes through the
thermal conductivity cell 19 to the column 10.
When the opening 60a passes out of the path of the
beam, the relay _46 is de-energized, thus interrupting the
?ow of current through the winding 12a of the motor 12.
The relay 36 is de-energized but the recorder input termi
nals 33 remain short-circuited through the ?rst contact
of bank 35b.
When the leading edge of the tab 55b intercepts the
are a plurality of tabs 55a to 55g which are arranged to
beam between the lamp 56 and cell 57, relays 36, 43 are
interrupt a beam of light passing from a lamp 56 to 30 energized with the result that the selector switch moves
a photoelectric cell 57. Each tab has indentations 58
to its second position. The recorder input terminals are
formed therein, FIGURE 3, which ?t within circumfer
short-circuited by the relay 36, and the chart motor starts
ential slots 59 adjacent the edge of the disc 52. Thus,
to run by virtue of the closure of contacts 43a. The in
the tabs can be mounted on the disc or removed as de
sired, and can be placed at any deisred angular position
along the edge of the disc.
A pair of openings 60a, 60b are formed in the disc, and
these permit passage of a beam of light from a lamp 61
to a photoelectric cell 62. The lamps 56, 61 are con
nected in series with the secondary winding of a trans
former 63, the primary winding of which is energized
from the terminal 54.
The cell 57 is connected through a transistor ampli?er
composed of transistors 64, 65, and ?xed resistances 66,
67, 68 and 69 to the operating winding of the relay 43,
which is connected in series with the operating winding
of the relay 36. In similar fashion, the photoelectric cell
62 is connected by a transistor ampli?er including tran
sistors 70, 71 and ?xed resistances 72, 73, 74, and 75 to
the operating winding of the relay 46 which is also con- .
nected in series with the operating winding of the relay 36.
Accordingly, when a tab 55 passes between the lamp
56 and cell 57, the relays 36, 43 are energized until the
tab passes out of the path of the light beam.
When an
opening 60 passes between the lamp 61 and cell 62, the
relays 36, 46 are energized until the opening passes out of
the path of the beam, it being noted that the two tran
sistor ampli?ers are oppositely poled to accomplish this
function.
dicator lamp 51a is illuminated through the second con
tact of bank 35!: and a circuit is prepared connecting the
bridge output terminals 31, 32 to the recorder input ter
minals 33 through the lead 37 and the second contact of
banks 35a, 35b. During this interval, a straight line 91
appears on the recording.
'
When the tab 55b passes out of the path of the light
beam, the relays 36, 43 are de-energized. The chart mo~
tor, however, does not stop because it is energized from
source 44 through the second contact of bank 350. The
circuit previously prepared through the recorder input ter
minals, lead 37 and the bridge becomes effective due to
the opening of the circuit between the input terminals
33 at the contacts 36a which are now open. As a result,
the recorder traces a horizontal calibrating line 92 repre
sentative of the bridge output, without attenuation, caused
by the passage of carrier gas through the column 10, it
being noted that the carrier gas passes through the ther
mal conductivity cell 21 from the column outlet.
Thereupon, the tab 55c intercepts the beam between
the lamp 55 and cell 57, thus maintaining rotation of the
chart motor and short-circuiting the recorder input termi
nals. This traces a horizontal line 93 on the chart, FIG
URE 4. The resulting closure of the contacts 43b steps
the selector switch to its third position. When the tab
550 passes out of the path of the beam, the relay 36 is
The selector switch has a motor magnet 356 with a unit 60 de-energized but the recorder input terminals remain
comprising a ?xed resistor 76 and a series-connected con
short-circuited through the third contact of the bank 35b.
denser 77 in parallel therewith.
One terminal of the
Movement of the chart motor stops upon the de-energiza-_
motor magnet is connected to neutral while the other
terminal is connected by a lead 78a to a normally open
contact set 43b of the relay 43. The armature of this
contact set is connected to a grounded condenser 78 and
the other ?xed contact is connected to a direct current
supply terminal 79. The motor magnet is further con
nected through an interrupter contact 80 to the termi
nals of a reset bank 35,‘ of the selector swtich, the arm
of this bank being connected to a direct current supply
terminal 81 through a set 46b of normally open con
tacts of the relay 46.
It will be apparent, therefore, that each time a tab
tion of the relay 43 and opening of contacts 43a.
_ Next, the opening 60b permits passage of light from
the lamp 61 to the cell 62. thus energizing relays 36 and
46. Responsive to the closure of contacts 46a, the wind
ing 12!) is energized through the third contact of bank
55 passes between the lamp 56 and cell 57, the switch
The components of the sample thereafter appear, in suc
35d. thus causing the motor to run in reverse direction
and move the valve 11 to its second position where the
sample passes to the pressure regulator 16 and vent pipe,
while carrier gas passes through the cell 19, sample loop
15, column 10, and cell 21 to the vent line 22, thus dis
placing a constant volume of the sample to be analyzed
from the loop and causing it to ?ow through the column.
3,023,605
cess1on, in the column ef?uent in order of increasing
at?nity for the sorptive material within the column. ' ~
When the opening 60!) passes beyond the beam, relay
46 is de-energizcd to stop the valve motor 12 and relay
36 is de-energized. However, the recorder input termi
nals remain short-circuited through the third contact of
the bank 35b.
When the tab 55d intercepts the beam between the
source 56 and cell 57, relay 43 is energized to start the
lays is obtained through the use of the transistor ampli
?cr circuits, and the tabs upon the timing disc permit any
desired sample to be analyzed with the proper program
ming cycle.
1 claim:
I. In an analyzer, in combination, a rotatable disc. a
series of tabs detachably secured to the edge of said disc
in predetermined relative positions selected by virtue of
a prior knowledge of the sample constituents, a recorder
recorder motor 42 through closure of contacts 43a, and 10 having a chart motor and a set of input terminals, means
cooperating with said disc to provide a control impulse
to advance the selector switch to its fourth position
during the times a tab is positioned within a preselected
through closure of the contacts 43b. This traces a hori
area along the circumference of said disc, means respon
zontal line 94 on the recorder chart, FIGURE 4. The
sive to such control impulses to energize the chart motor
potentiometer 34a is thus placed in circuit between the
bridge output leads 31, 32 and the recorder input termi 15 and short-circuit said input terminals when a tab is posi
tioned within said area so as to produce a null record in
nals 33, but these latter terminals are short-circuited at
said recorder of ?nite interval determined by said control
this time by the closure of relay 36 and contacts 360.
impulse, the motor being de-energized and the input ter
When the tab 55d passes out of the path of the beam,
minals open-circuited so as to receive a signal propor
analysis of the ?rst component of the sample begins, this
period lasting until the tab 55c intercepts the light beam. 20 tional to unbalance between a later-mentioned pair of
thermal conductivity cells when no tab is positioned
within said area, thus producing a bar-graph record in
said recorder proportional in amplitude to said unbalance,
virtue of a prior analysis of a sample having a generally “
a plurality of openings in said disc, means responsive to
similar constitution, so that the tabs can be readily placed
25 the positioning of one of said openings at a predetermined
in proper position upon the disc.
,
.
angular position to provide a second control impulse, a
The described passage of tab 55d out of the path of the
two-position valve, a sample loop cooperating therewith,
beam de-energizes the relay 36. thus open-circuiting the
a chromatographic column, a sample source, a source of
recorder input terminals 33. Thus. the potentiometer
carrier gas, a pair of thermal conductivity cells, said valve
3411 is inserted in the circuit between the bridge and re
corder input terminals, and this unit is adjusted to give 30 in its ?rst position ?owing sample from said source
through said sample loop to vent, and ?owing carrier gas
the proper recorder sensitivity based on the thermal con
through one cell to said column and then through the
ductivity of the ?rst component of the sample which now
second cell, said valve in its second position ?owing car
appears in the ctlluent from the column 10 and passes
rier gas through said one cell and said loop to said
through the cell 21. The chart motor is de-energized dur
ing this period due to the opening of the contacts 430, and 35 column and then through the second cell, and means for
applying said second control impulses to said valve to
the indicator lamp 511) is illuminated by virtue of the
cause it to alternate between its ?rst and second positions.
closure of the fourth contact of bank 3511. In‘ this man
The length of this analysis circle is determined by the
relative positions of the tabs 55d, 55c and is selected, by
ner, a vertical line 95 is traced upon the recorder chart,
2. In an analyzer, in combination, a rotatable disc, a
series of tabs detachably secured to the edge of said disc
the height of which represents the concentration of the
40 in predetermined relative positions selected by virtue of a
least sorbable component of the sample.‘
prior knowledge of the sample constituents, a recorder
As rotation of the disc continues, the tabs 55c and 55/‘,
in turn, intercept the light beam as the different com
ponents of the sample pass, in succession, from the
column 10. As each tab intercepts the beam, the chart
having a chart motor and a set of input terminals, a ?rst
contacts, not shown, on the selector switch, additional
components can be analyzed, as desired.
of openings in said disc, a second light source and a sec
light source and a ?rst photoelectric cell cooperating with
said disc to provide a control impulse during the times a
motor operates and the recorder input terminals are short 45 tab is positioned within a preselected area along the cir'
cumference of said disc, a transistor ampli?er fed by said
circuited, thus producing short horizontal lines 96, 97
cell, selector switch means responsive. to ampli?ed im
upon the recorder chart. During the interval between
pulses from said ampli?er to energize the chart motor and
tabs, the chart motor stops and the appropriate potenti
short-circuit said input terminals when a tab is positioned
onteter 34 is inserted in the recorder circuit to provide
within said area so as to produce a null record in said
the proper recorder sensitivity for the component then
recorder of ?nite interval determined by said control im
under analysis, vertical lines 98, 99 being traced upon
pulse. the motor being de-energized and the input. ter
the recorder chart during these intervals which are repre
minals open-circuited so as to receive a signal proportional
sentative of the concentration of the other components
to unbalance between a later-mentioned pair of thermal
of interest in the sample.
conductivity cells when no tab is positioned within said
The chart, FIGURE 4, indicates an analysis of three
area, thus producing a bar-graph record in said recorder
components. By the use of additional tabs, for example,
proportional in amplitude to said unbalance, a plurality
tabs 55a and 55g as shown in FIGURE 2, and additional
ond photoelectric cell responsive to the positioning of one
After the last component is analyzed, relay 46 is ener 60 of said openings at a predetermined angular position to
provide a second control impulse, a transistor ampli?er
gized by the passage of opening 600 between the lamp 61
fed by said second cell, a two-position valve, a sample
and cell 62. This applies power through the contacts
loop cooperating therewith, a reversible motor con
461: and the last contact of the reset bank 35f of the
trolling said valve, a chromatographic column, a sample
selector switch causing it to return to its original position.
Thereupon, motor 12 is actuated to return the valve 11
to its ?rst position to initiate a new cycle of analysis.
It will be evident that l have achieved the objects of
the invention in providing a programming circuit for a
source, a source of carrier gas, a pair of thermal conduc
tivity cells, said valve in its ?rst position ?owing sample
from said source through said sample loop to vent, and
?owing carrier gas through one thermal conductivity cell
chromatographic analyzer which is very ?exible in opera 70 to said column and then through the second thermal con
tion. permits an accurate volumetric amount of the sam
ductivity cell, said valve in its second position ?owing
pie to be fed to the column during each analysis cycle,
and inserts the proper impedance in the recorder input
carrier gas through said one thermal conductivity cell and
said loop to said column and then through the second
thermal conductivity cell, said selector switch means con
trolling ampli?ed second control impulses to cause said
circuit to sensitize the recorder for each component to be
analyzed. Finally, positive ef?cient actuation‘ of the re
3,028,605 '
7
8
motor to move said valve alternately to its ?rst and vsec
2,826,908
2,833,151
2,875,606
0nd positions.
References Cited in the lilc of this patent
UNITED STATES PATENTS
5
Y
571,003
601,850
Burrill ________________ _._ Apr. 5, 1898
1,904,029
1,966,958
2,268,133
Knopp ____________ __'_.... Apr. 18, 1933
Skarstrom ___________ _.. Mar. 18, 1958
Harvey _______________ __ May 6, 1958
Robinson _____________ __ Mar. 3, 1959
FOREIGN PATENTS
Great Britain __________ -_ Aug. 1, 1945
OTHER REFERENCES
Fisher _______________ __ July 17, 1934
Article: Gas Chromatography, published
Carlson ______________ __ Dec. 30, 1941 10 Gas Journal, Dec. 17, 1956, pp. l26—140.
in Oil and
~
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