Note: Descriptions are shown in the official language in which they were submitted.
38,974B-F
~_ MEMBRANE-BASED FLUID SEPARATIONS APPARATUS
Thepresentinventionrelatestodevicesforselectivelyseparatingoutcertain
5 materials from within a complex matrix stream or agg, egdlion of flowable materials, and more
particularly to such devices which employ ,ue- me~lion mê".brdne or diffusion membrane
tubing to coilect and isolate these certain materials from within the stream or aggregation.
The present invention further relates, in one significant aspect, to ",e",brane tubing-based
devices useful in the detecting, monitoring and/or measuring of IOJ/ leVCI concenlrdlions of
10 materials within a stream or agy. ega Lion, both in an on-line process environment and in an
off-line, purely analytical context or envi-on...enL.
Tubular membranes have been sugg-~l~d for uSê in this capacity in a number of
analyticaldevices,andareparticularlyofinterestforuseinsepardlingoutthoseco""~onenLs
of a complex stream which might adversely affect a gas or liquid chromdlog, aph or other
15 analyticaldeviceifoneattemptedtoanalyzetheco"",leAstreamdirectly. Exemplaryofthese
devicesarethosedescribedinUnitedStatesPatentsNo.4,715,217toCoyneetal.and4,944,180
to Tou et al., both of which are commonly-assigned and owned with the present invention.
Tubular membranes have also been utilized in on-line, direct insertion systems for
the real-time monitoring of certain loJ/ leJel materials in a matrix stream of materials, but in
20 limited circumstances. For example, in United States Patent No. '1,8~7.0~q to Pizziconi et al., a
length of capillary membrane is inserted directly into the blood stream of a patient for
monitoring biological reactions and trends. A similar device is des~,ibed in Brodbelt et al., ~In
Vivo Mass Spe.L,umetric Determination of Organic Compounds in Blood with a Membrane
Probe",Anal.Chem.,1987,Vol.59,pages45W57,whereina.,.e.,.braneprobeissuppG,led
25 internal Iy over a portion of its length by the insertion of a nylon monofilament and is used in
vivo.
United States Patent No. 3,483,990 to Litle describes a membrane-based dialyzer
device which ope,ales eAle",ally of the patient's body, and which is coupled with a dual-lumen
catheter to be inserted into the patient's vein. The dialyzer is co",p. i,ed of a cylindrical, sheath-
30 type dialysis me. . .brane into which is inserted a helically yl ooved, cylindrical support core forproviding a helical flow path for a saline carrier solution along the inside of the sh
eath
membrane. A heparin/saline solution is pumped through the inner lumen of the dual-lumen
catheter, and combines with blood and is returned via the outer lumen to the dialyzer. In one
embodiment, the heparin/blood solution follows an annular flow path along the outside of
35 the dialysis membrane. In a second embodiment, the cylindrical outer housing is also helically
grooveJ, so that helical flow paths are defined along both the inside and outside of the sheath
membraneforthesalinecarrierand forthe heparin/blood solution"espe~lively.
' - -
74453-20
Other membrane-covered probes have been used apparently
for monitoring and controlling the reactions in bioreactors. In
Cox, "Membrane inlets for On-~ine Liquid Phase Mass Spectrometric
Measurements in Bioreactors", Mass SpectrometrY in
Biotechnoloqical Process AnalYsis and Control Plenum Press, 1987
at pages 63-65 is described a perforated stainless steel tube
which is capped at one end and which is inserted into the core of
silicone rubber tubing. Other devices are described which appear
to be of a fundamentally similar nature.
The known tubular membrane-based devices posses various
shortcomings, however, in terms either of versatility of use in
both process and analytical contexts or environments, of an
exposure of the membrane to abrasion or cutting by particulates or
other suspended debris (e.g., flakes of rust from the inside of a
process pipe) in a matrix stream or to damage or destruction in
pinch points within a pipe, reactor, other process vessel or
instrument, or of having a length of membrane for effecting a
separation which is limited either by its unsupported nature and
an accompanying tendency to elongate and distort or by space in
the instrument or process vessel.
The present invention in contrast provides an apparatus
for supporting a length of permeation or diffusion membrane
tubing, a capillary column, optical fiber or the like in a manner
which protects the membrane tubing, column or fiber from such
influences as have been described, the apparatus comprising a
support member having a groove defined therein, and a conduit in
the form of said membrane tubing, capillary column or optical
A~--
74453-20
fiber which is positioned and supported substantially wholly
within at least a portion of the grove in the support member,
wherein such influences may be encountered.
The apparatus of the present invention is thus useful in
one aspect for determining the presence and/or concentration of
one or more selected materials in a significantly larger matrix
stream or aggregation of flowable materials within a process pipe,
reactar or other process vessel. The apparatus of the present
invention in this particular aspect broadly comprises (a) a
support member having a first, internal end for inserting into the
matrix stream or aggregation when the apparatus is placed in
service and a second end positioned externally of the pipe,
reactor or other process vessel in use, wherein the support member
defines a groove therein of which at least a portion extends into
the matrix stream or aggregation in use, and (b) a conduit, in the
form of permeation or diffusion membrane tubing or optical fiber,
which is positioned and supported sub~tantially wholly (and
preferably wholly) within at least
2a
~8,!174B-F
that portion of the groove i n the support " ,~. "be~ which extends i nto the matrix stream or
agy,cgalion in use.
More commonly permeation or diffusion membrane tubing will be employed for
this application. With respectto optical fibers, I o~J_~er, it has been appreciated in conjunction
5 with the present invention that such fibers could (like the aforementioned tubular membranes)
beinsertedintoamatrixstreamoragg~egdlionofflowablematerialsfordeterminingthe
presence and/or concentration of one or more selected materials therein by known attenuated
total reflectance (ATR) ~"ell,ods. By such ",ell,ods the one or more selected materials of
interest adhere or are captured on the ~ osed surface of the clad or unclad fiber, and are
10 analyzed through the selective absorption by these materials of near-infrared light traveling
over the length of the optical fiber.
With the addition of lc,"pcrdlure monitoring or regulating devices, for example
through the incc rpordlion res,ue~Li~ely in a thermally-conductive support member of a
thermocouple (or known resistive temperature device (RTD)) or of a thermocouple and
15 cartridge heater, the appd~dlus of the present invention is also effectively capable of
accounting for or regulating the temperature atthe illlc, ra,e of a tubular ~nembr~ne and a
given flowable material, and the permeatiol Jl. ansrer chard.lc, ;,lics associated with that
temperature.
These two fundamental grooved support member constructions can also form the
20 bases of other related types of separations appdralus. For example, in the area of fluid drying,
typical membrane-based apparatus are configured as a "tube within a tube", wherein a
tubular ",embrane is cli~,uosed between two capped ends of a pipe and a drying agent is eithèr
disposedasasolidontheoutside/shellsideofthe",e.nbr~,neorflowsasaliquidorgasdrying
agent on the shell side of the membrane.
The "tube in a tube" me."brane-based dryers having a quantity of a solid drying
agentdisposedaroundthetubular,,,e,,,br~,nearefairlyine,~,uersi~e,butthesoliddryingagent
is difficult to change, and changing the drying agent requires disassembling the dryer and
stopping the flow of a gas or other fluid through the mcr ,b, dne. This flow stoppage causes
difficulties, obviously, in those analytical instruments and appa.dlus which require a steady
30 flow of a high purity dry gas thereto. The dryers employing a flowing stream of a liquid or dry
gas drying agent were developed to avoid the changeout and flow stoppage problems
associated with solid drying agents, but these dryers are considerably more e.~.ensive on the
whole than those employi ng sol id drying agents.
In addition, in both designs the tubular ., ,c, "b, dne must again be self-supporting,
35 whichlimitsthelengthandthinnessofthen.c..,brancandthustherateofmasst.dn~rcrand
drying that can be achieved with such a meml;,ane. Further, the surface of the me."brane is
exposed and subject to abrasion and wear by contact with the drying agent employed.
38,974B-F
'~ By employing one or the other of the grooved support member constructions of
the apparatus of the present invention, there is no need to disconne~l the membrane
SUppGI led ll.ereon and to interruptthe flow of gasesto an associated analyzer (so thatthe less
exper,sive solid drying agents can be used), a much longer and thinner membrane can be used
5 if desired, and the membrane is pruLe~èd from most of the abrasion and damage which would
otherwise occur in a conventional design having a more exposed ",e."brdne.
Another potentially useful application for the 9, ooll~d support member
constructions of the appardLus of the present invention which has been suggested above, is as a
support for the capillary column for a self-contained capillary gas chromatographic or self-
10 contained, pGI lable capillary gas chromaloy, dpi~iC appardl.Js. The "conduit" in this context isacapillarycolumnratherthanpermeationordiffusion",e",brdnetubingoranopticalfiber. In
particular, it is e-~pe~Led thatthe support ,ne."ber construction having internal temperature
monitoring and/or temperature regulating means associated therewith will be especially
useful as a capillary column support.
The 9l oovad support members of the appdral-ls of the present invention and the
various extensions and applications thereof are ill ustrated and described in greater detail as
follows.
Figure 1 is a top view of a yl oo~ ad support member in one embodiment, absent accr,esponding length of membranetubing, capillarycolumn oroptical fiber.
Figure 2 is a cross-sectional view of the ap,uardlus of Figure 1, taken along line 2-2.
Figure 3 is an end view of the apparatus of Figure 1, taken from the pe,spe~Live of line 3-3.
Figure 4 is an enlarged cross-sectional view of the appardlus as depicted in Figure
2 with a length of membrane tubing added.
Figure 5 is a side view in partial cross-section of an alternative, prerer,ed
25 embodiment of a grooved support member.
Figure 6 is a sectional view of the embodiment of Figure 5, taken along I ine 6-6.
Figure 7 is an end view of the embodiment of Figure 5, as taken from the perspective of line 7-
7.
Figure 8 is a cross-sectional view of an apparatus for on-line calibration in a
30 process control context of a device of the types shown in Figures 1-4 and 5-7.
Fi9ure9isacross-sectionalviewofanalle.~dleappar~Lusfortheon-line
cali bration of a device of the types shown in Figures 1-4 and 5-7.
Figure 10showsaplete"edmannerofjoininganappardlusofthetypeshownin
Figures 5-7, a source of a receiving fluid and an analytical appa,dlus in fluid communication.
Figure 11 is a partially cross-sectional view of a flow cell apparatus which employs
anapparatusasshowninFigures5-7foranalyzingaslip~lreallloffalargerprocessstream~
Figure 12 depicts a prere.-ed me",brane-based fluid separdLions apparatus (e.g.,
fluiddryer)whichinco,~,alestheapparatusofFigures5-7and 10.
JI
38,CJ74B-F
Figure 13 is a cross-sectional view of a carrier gas gena,dlor useful in a portable or
self-contained capillary gas chromalog(aphic apparatus, in combination with the apparatus of
Figures 1-4 or of Figures 5-7 and 10.
Figure 14 is a general schematic diagram of a self-contained capillary gas
5 chromatographic apparatus or self-contained"~- lable capillary gas chromatographic
apparatus which employs the gene, d Lor of Figure 13 and which may further employ the
apparatus of Figure 12 and/or the sampling apparatus of Figures 5-7 and 10 or Figure 11, along
with a capillary column support configured as in Figures 5-7.
Figure 15 is a schematic diagram of a portable or self-contained capillary gas
10 chromatographic appa,dlus in a prere"ed embodiment.
Figure 16isagraphical repleselllalionofdatafrom Example 1.
Figure 17 is a graphical represen~a~ion of data from Example 2.
Figure 18 is a graphical ,ep,ese"lalion of data from Example 3.
Referring now to Figures 1-7 and 10, two alternative embodiments of a grooved
tubular membrane/capillary column/optical fiber support member are depicted. A first
embodiment or elementsthereof is shown in Figures 1-4, while a p(are"ed alternative
embodiment and elements thereof are addressed in Figures 5-7 and 10.
TurningnowtoFigure1,thefirstembodiment10includesasupport",e",ber12
which is c~r"p, ised of a first, single-flight lhreaded portion 14 and a second, unthreaded
20 portion 16. Agroove 18isdefined intheme.nber 12whichcutsthroughthethreadsof
threadedportion 14fromafirstend220fthe"-e.nber12towardasecondend200fthe
member 12 (see Figures 2 and 3).
Afirsthole24isdefinedthroughthe",~:",ber12adjacentthesecondend20and
incommunicationwiththegroove 18,whileasecond hole26isdefined inthethreaded
25 portion 14nearitsboundarywiththeur,ll,readedportion 160fn,e "ber12.
This second hole 26 prererabl~r extends into the support member 12 at an angle,
and terminates in a central channel 28. Channel 28 defines an opening 30 into the core of
member 12 at the first end 22 of member 12, and extends generally along the longitudinal axis
of member 12, terminating at some point short of i"le,se-ling with the first hole 24 but at least
30 being in communication with the second hole 26.
The manner in which a capillary membrane or other ~conduit~ is SUppG~ led by
the support member 12 is shown in Figure 4. In Figure 4, and as described in the context of
using the apparatus for direct-insertion sampling from a stream or agg, eyalion of flowable
materials, a capillary membrane 32 feeds from a source of a receiving fluid (not shown)
35 through openi ng 30 at the first end 22 of n ,a, nbar 12, and extends through central channel 28
and the second hole 26.
On exiting channel 28 through the second hole 26, the ~"emb, dne 32 traverses
the threaded portion 14 of member 12 via the groove 18 ùntil the first hole 24 is reached. The
-5-
~ .
38,974B-F
membrane 32 then feeds through the hole 24 and begins winding its way back along the
lengthofthemember12throughsucc~ssi~_flightsinthethreadedportion 14,whilebeing
positioned and suppo, led wholly within such flights in the sense that no portion of the
membrane 32 in a flight extends above the thread crests 34 defining the flight on either side.
Inthiswaypotentiallydamagingparticulatesordebrisinastream inwhichthe
suppo, led membrane 32 is immersed come into contact with the crests 34 rather than the
membrane32. Inasimilarfashion,the",~."~rane34isplo~cl~dfromtheelongatingor
distorting influence of the surrounding stream due to the support provided by the flanks 36 of
adjacent threads. Where the stream to be " ,oni lc,red has a relatively high flow rate and is likely
10 toexertagooddealofforceonanunsuppo,~~ll",~."brdne,aswillbethecaseinmanyprocess
streams of interest, this feature is likely to be of significant value.
As the " ,e" ,brane 32 reaches the second hole 26 from which it (i .e., the
membrane32)originallyemerged,the",e",b,dne32isfedbackthroughthehole26and
channel 28 and e" ,eryes from the opening 30.
The "~er,~trane tubing 32 is then placed in fluid communication with means for
analyzing a stream of receiving fluid circulated through the me",brane 32 in use of the
apparatus, plererably bytubing or some other meanswhich is inertto, and which does not
relewith~ lldn~lllis~ionoftheselected materialsreceivedfromamatrixstream inwhichthe suppcl, l~d membrane 32 (or other conduit) has been placed. Depending on the nature of
20 the materials to be collected from the matrix stream and of the receiving fluid, the analytical
means employed can include, for example, a gas chromdlog, dph with mass spe~ ,,nel~r or a
liquid chromaloy,dph.
Inanother,morepf~re"~dembodiment380fthey.oo~dsupportmember
which is shown in Figures 5-7 and 10, the support, llelllbe~ 4Q has a double-lead flight threaded
portion 42 and an unthreaded portion 44. Two ~l ,ann~:s 46 and 48 are defined longitudinally
through the l",lhreaded portion 44, and emerge at a shoulder 50 of the unl~" eaded portion 44
in position to receive from or lldn~lllilto a helical flight of the adjacentthreaded portion 42 a
membrane 52 suppcil led therein. Short, curving transition channels (not shown) may
preferably be provided in the surface of the unlh, eaded portion 44 adjacent the shoulder 50
for easing the transition of the membrane 52 be~t~reen the d,ann~ls 46 and 48 and the flights
ofthethreaded portion42. ~,ere,dblycapillary,ne",blal,eendsplaced inthesechannels46
and 48 are adapted to be joined in secure fluid communication with a source (not shown) of a
receiving fluid and with a gas or liquid chromdluy, aph (also not shown) or the like,
,e",e~lively.
The p,esefilly ple~"~d construction for joining the ",e",b~ane 52 in
communication with a source of a receiving fluid, and in turn with a gas or liquid
chromdlog,dpl)orthelike,isshowninFigure1Q,whereinoneendofalengthofmembrane
support tubing 53 is inserted into and holds open the central lumens of the n,~"~b(ane tubing
1~
.~ '
38,~74B-F
~ 52. This membrane support tubing 53 can be made of, for example, stainless steel or a fused
silica glass.
Membranesupporttubing53isinturnsecurelyjoinedviaatwoferrule
compression-type fitting 55 to a conventional tubing lead (not shown, and comprised, e.g., of
5 stainless steel or nickel) to the gas or liguid chromatograph. A co""~në,sion-type tube-to-tube
bulkhead fitting 57 ties the assembly 55 and a me",brane sealing ferrule 59 into an inleg, ated
whole, with the fitting 57 being joined to the support ,ne",ber 40 by the threaded
engagement of fitting 57 with a threaded portion 61 of a channel 46 or 48 in the unthreaded
portion 44 of support ,ne"~ber 40
The n,el"brane tubing 52 associated in use with the support member 40 thus
enters the unthreaded portion 44 through channel 46 from a first end 54 of the member 40 and
from a source of the receiving fluid to be employed in ,,,en,b,c,ne 52.
ReturningnowtoFigures5-7,the-ne."b,ane52isthen~ ppedaroundthe
support member 40 through alternating flights 56 (Figurè 5) toward a second end 58 of
15 member 40, with the membrane 52 being positioned and s~")po. led wholly within the flights
56 as in the embodiment of Figures 1 -4.
Atthesecondend 58Ofthesupport",e.nber40,andasbestshown in Figure6,
the membrane 52 then travels through an S-shaped channel 60 in the second end 58 of the
support member 40 which joins the al le" ,aling helical return flights 62 in communication with
20 theflights56. The",e",brdne52intraversingflights62thusisu,appedaroundmember40through those allel "dling flights which had been "skipped" in going from the first end 54 of
the member 40 to the second end 58 of ,ne",ber 40.
The membrane 52 returns to and is recei~red by the channel 48 in the unthreaded
portion 44 of the support member 40. The receiving fluid and any selected materials collected
25 by the membrane 52 and carried by the receiving fluid are communicated through channel 48
toagasorliquidchromatograph,prere,ablybythear,ange",erildepictedinFigure 10and
described above.
A prolé~ e cap 64 is placed overthe S-shaped channel 60 in the second end 58 of
the support r"e",ber 40, and is conventionally joined to the support ",e",ber 40 as through
30 bolts or screws placed through holes 66 in the cap 64 and co, ~es~,onding holes 68 in the second
end 58 of support ".e."bêr 40. The function of ~.,ole~ e cap 64 isto help contain the
",e."brane 52 in the S-shaped channel 60, and furtherto protectthe me."b(~ne 52 in the S-
shaped channel 60 from damage should the appardlus be inserted too far into a process pipe,
forexample,andencountertheoppu,ilewallofthepipe(assumingap.ere-,èd,generally
35 transverseprese"l~lionorinsertionwithrespecttothematrixstream~asopposedtoanaxial
insertion) or should the apparalus' second end 58 encounter some other obstacle on insertion.
It may also be desirable to employ the cap 64 as a spacer of sorts, wherein the cap
64 would be sized so that when the second end 58 is placed against a pipe wall or the like, the
,~
.~
38,CJ74B-F
membrane 52 in the threaded portion 42 of the ,.,e".ber 40 would be ~cre.isely and controllably
positioned in the matrix stream, as for example to avoid encountering fouling on the inside
walls of the pipe. It should be observed thatwhile the protective cap 64 is illustrated only with
respect to the embodiment of Figures 5-7, a similar p, ole~live cap or spacer could be readily
5 employed in the el"bodi",ent of Figures 1-4.
In the indicated use of either of the two embodiments depicted in Figures 1-7, aportion of the capillary membrane or other conduit associated with a device is ~,osed to a
complex process stream or aggregation of flowable materials in, for example, a pipe, reactor or
other process vessel (the stream or ayy~egalion containing or carrying one or more selected
materials therein of interest) by inserting the first end of the device into the stream or
aggregation. Where the process stream is of a character and/or flow rate which is likely to
damage a bare, unsuppo, led ",el"b, ane, then at leastthat portion of the membrane ~Yposed
to the process stream is positioned and SUppGI led substantially wholly (and preferably wholly)
within a groove defined in the device and extending from the first end of the device toward
the second, external end of the device. "Groove" in this sense and as used elsewhere herein
embraces the threaded flights of either of the embodiments shown in Figures 1-7, but is not
limited thereto. What is intended for purposes of the present invention and disclosure is that
those portions of a capillary membrane (or other conduit) which are immersed in and ~Yrosed
topotentiallydamagingordistortingenvi~on",e(,lsshouldbep,ole~ledfromthese
20 envi ronments, by bei ng SUppGI led and positioned within a . e.essed portion (groove) of the
body of a support member.
It is adv.,h lageous, ho lJcvcr, for i.. lpfO.';ng the overall ser,~ /; ly of the devices
shown in Figures 1-4 and 5-7 thatthe portion of ~"e",b-dne available for insertion into a
process stream or agylegdlion be longer, ratherthan shorter, for a given membrane sothatthe
25 contact area between the membrane and stream or aggregdlion is ir,., eased. A greater
contact area permitsthe recovery of a greater amount of a given lo~ l material in a stream
over a given length of time, and consequently enables the more timely and effective
monitori ng of such a material. A continuous groove in the form of threads on a support
memberisforthisreasontobep,ere"edoveragroovep~oceeclingmoredirectlyfromthefirst
30 end toward the second, e..l~., .al end of the device. For th;s reason as well, it ;s cons;dered that
the double-lead flight threaded embodiment of Figures 5-7 (in which the threaded flights
going from the second end to the first end, and from the first end back toward the second end
may be thought of as two conne~led grooves (a first groove for traversing the support member
inonedirection,andasecondgroovefortraversingthesupportmemberinthereverse
35 direction, for example, toward the insertion point of the device into a process pipe orthe like))
willnormallybepre~e..edoverthesingleflightl~"~adedconstructionofFigures14.
By similar reasoni ng, normally it will be desirable: (a) for the groove carrying the
me",b,aneinagivenappa,dlustoextendfromthefirst~internalendofthesupport,,,embe
-8-
.~_
A~
38,974B-F
- toaninteriorwalloftheprocesspipe,reactororothervesselinwhichtheapparatusisused,or
where the stream in question does not substantially fill a pipe or vessel to such interior wall, at
least to span as much of the matrix stream as possible and as cor,si~ nlwith the effective use of
the device (see i n this regard the earlier discussion of the pfole.li~ e cap as a spacer); and (b) for
5 the membrane carried within such groove to be essentially coeAlensive with the groove.
Thus, in the embodiment of F;gures 1~ the threaded portion t4 of member 12 is
preferablydesignedtoextendfromitsfirstend20toaninteriorwallofapipe,reactororother
vessel into which the appara lus is inserted, and the second hole 26 into which the membrane
32returnsisprererablynearthein~e,raceoftheu..lh,eadedandtl"eadedportions16and 14,
10 .espe~lively, ofthe member 12. Similarly,the inte, ra.e betweenthethreaded and unthreaded
portions 42 and 44 of the more p(-:re"ed embodiment is preferably designed to cor.èspond to
an interior wall of a vessel or pipe in which the appar.,lus is e."plo;l_d.
As the membrane of an appar~ s is I ..posed to the matrix stream or aggreydlion
and to the one or more selected materials of interest therein, an appf~,p, iate receiving fluid
(which may be either a gas or liquid) is circulated through the central lumens of the membrane.
The materials to be collected by the me"~b,.3i~e from the matrix stream permeate or diffuse
through the walls of the membrane and into a receiving fluid, and the receiving fluid carries
the collected materials to some analytical means, such as a gas chromatoy, dph/mass
spe~l,o",eter combination or a liquid chromalog, aph.
The circulation of the receiving fluid and/orthe analysis of the receiving fluidfrom the ",e",b,dne of a device may be manually initiated, or one or both may pr~r~:,ably be
initiated by some conv_n~ionally-known remote automated means for accon,plish;ng this
function so that sampling and analysis of the process stream may be more conveniently done.
Suitable apparatus are known to the art and are described, for example, in Automated Stream
Analvsis For Process Control Vol. 1 (Academic Press, Manka ed., 1982) and Nichols, On-Line
Process Analyzers (John Wiley and Sons, 1988).
Itwillbeprere"èdinmanyapplications,also,thatthemeansforanalyzingthe
receiving fluid from the membrane be coupled to some sort of process control, for example, to
anycomrcnlionally-knownmeansforredirectingtheflowand/orforalteringtheco",po~ilion
30 of the stream being mo"i lored responsi~e, for example, to the p, esence in the stream of a
given concen~,d~ion of one or more selected materials.
Intermsoffurtherchara~Le~ nythecapillary~eml~a~es(orotherconduits
generally), support me" ~be~ s, receiving fluids and analytical devices useful in this application
and use of apparatus of the present invention, all of these elemenL~ are application-dependent
35 anditisconsideredthatthoseskilledintheartwillbewellabletoselectanapprup,iate
combination of these elements for a given application without undue experimentation.
L~
38,974B-F
With respect to the tubuiar ",e,l,b,dnes useful in the present invention, it is
believed that pe""eaLion membrane or diffusion ",e.nbrdne tubing may variously be used and
selected depending on the intended application of the appardlus.
Itwillgenerallybeprerer~èdforagivenmembranethatthewallthicknessofthe
5 membrane be selected to be as thi n as possible to keep the ",e,nbrane intact and the central
lumens of the membranefully open throughoutthe m~"brdne's length.
The support member can be made of any number of materials, but preferably will
be inert to its envirc r" "ent and will have a degree of chemical re,i~ldnce and resistance to wear
by flowi ng particulates or debris a~,prop, iate to the stream in which the support member is to
10 beimmersed. Atthesametime,thematerialforthesupport",e",befshouldideallybe
relativelyine.~pensiveandshouldmachinewellsothatthethreads,.i,annels,groovesandthe
like of the support member may be incc.",ora~ed therein without undue expense or difficulty.
For devices employing a tubulam,~e",b, ane as the conduit, the receiving fluid can
be either a gas or a liquid. The particular gas or liquid is not critical to the invention as long as
the material received through the membrane is either volatile in the gas or soluble in the liquid
receiving fluid used, and as long as the receiving fluid itself does not appreciably permeate or
diffuseoutthroughthe",e",brane. Whenthereceivingfluid isa liquid,thentheanalytical
means employed for the receiving fluid can co,-~pfise a liquid chromatograph. When the
receiving fluid is a gas, then the analytical means preferably cc.""~. ises, for example, a gas
20 chromatograph and mass ,,ue.L.o",eter.
Standardization of the apparatus in an on-line, process control context can be
done in a couple of ways, depend;ng on wl ,ali.~r one may safely and practicably open a process
pipe or vessel and insertthe apparatus, or wl ~ethe~ external standardization of the device is
feasible.
Where external standardization of the device is feasible and can be safely done,the device may conveniently be designed and sized to be inse. lable through a gate valve or the
like into a process pipe or vessel. Standardization of this embodiment may simply involve
immersing and stirring the device in a bucket of water or other matrix containing a known
concenlr~llion of a material of interest.
It will generally be preferable forthe support member of this valve-insertable
device to be coupled, orto be at least capable of being coupled, to a stinger which is also
insertable through a standard gate valve to a process conduit or vessel. In practical terms, this
will involve sizing the u-lthrèaded portions of the probe embodiments of Figures 1-4 and 5-7 to
be joinabletoalengthofcon.~,.lional pipingbyapipingunion,withaferrulehavingbeen
35 placed around the unthreaded portion of the probe. The leads to and from a source of a
receiving fluid and the particular analytical means employed in an auparalus can then
preferably be prule~led by running these leads through the length of piping.
-10-
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;
A~'''
38,~174B-F
Where the process pipe, reactor or vessel is pressurized or under a vacuum, for
example, orwhere there is a need to limitthe exposure or risk of exposure of a person taking
the measurement of the stream or agg, egalion in question to such stream or agg, esaLion,
then an on-line standardization of the device is appr~ priate.
~his on-line standardization can be accomplished with the same valve-insertable
embodiment of the apparatus by constructing, as shown in Figure 8, an external calibration or
standardizationchamber70incommunicationwithavalve72andpositionedopposilethe
process pipe or vessel 74 containing the stream 76 to be ,nor,ilored. The valve-insertable device
10 or 38 is passed into the calibration chamber 70 through a sliding seal 78; when the valve 72 is
closed, the device 10 or 38 is isolated from the process pipe or vessel 74 so that a standard flow
80 may be passed through the chamber 70. The device (10 or 38) may then be moved directly
into the process pipe or vessel 74 by opening the valve 72 and inserting the device through the
open valve 72. The sliding seal 78 by which the device is entered into the calibration chamber
70preventsthe~or,te-,lsofthepipe,reactororvessel74fromcomingintocontactwitha
person employi ng the device.
Alternately, and as shown in Figure 9, a first sliding seal 82 may be provided
adjacent the valve 72 to permit the valve 72 to be safely opened and the device 10 or 38
inserted therethrough. For calibrating the device 10 or 38, the device is passed through a
second sliding seal 84 into an internal standardization chamber 86 defined in the pipe 74,
20 which chamber 86 receives a standard flow 88 lhe,~ti,rough. In still ar,vll,er method, a
standard (such as an inert gas or an isotopically-labeled analog of a compound in the process
stream) is merely injected into the process pipe 74 l" ,L-ea"\ of the device 10 or 38. Another
methodmightinvolveinler",ille"llyanalyzingastandardinastandardizationchamber700r86 while continuously introducing an internal standard u p~l,ean, of the device 10 or 38.
Discussion thus far has focused on use in the body of a matrix stream or
agy(egalion of flowable materials. In certain instances it may be necessary or desirable to
insertthe apparatus intoa slipstream taken from the matrixstream, l~o~e~r, and for purposes
of the defining claims below a slipstream of the matrix stream should be considered as
embraced within the confines of "a matrix stream or agy, egalion of flowable materials" . A
30 suitable flow cell apparatus 90 (a type of "process pipe,... or other process vessel" as recited in
the claims below) for utilizing an apparatus of the present invention in this fashion is shown in
Figure 11.
ReferringnowtoFigure 11~theflowcellappardlus9obroadlycolll~ sesa
standard piping tee portion 92, an elbow portion 94 and a length 96 of piping joining the tee
35 and elbow portions 92 and 94. A device 10 or 38 (a device 38 being shown) extends coaxially
through a cylindrical bore portion 98 of the tee portion 92, and with a ferrule and threaded nut
assembly 100 caps off one opening 102 of the tee portion 92. Side arm 104 of tee portion 92 is
coupled via a second ferrule and threaded nut assembly 100 to a pipe 106 from a
-t 1-
..,~
3~,974B-F
m~ " ocess stream, so that a slip,lrea"~ 108 may be taken from the matrix stream through
pi pe 106 and along the device 38 i n tee portion 92.
This slip,l-èa",108 continues along the device 38 and through the length 96 of
pi ping joi ning the tee and elbow portions 92 and 94, meslJe~ ely, and exits through a
5 downstreamend 1100ftheelbowportion94. Thelength960fpipingis joinedthrough
ferrule and threaded nut assemblies 100 at either of its ends to the ~espe.~i~/e tee and elbow
portions 92 and 94, while a return pipe 112 (for returning the slip,l- eam 108 to the matrix
stream) is joined to the downstream end 110 of elbow portion 94 via a final ferrule and nut
assembly 100.
It has been su99e~led above thatthe support ",e",be( can be made of materials
which p~ererdblywill beinerttothemember'senviror""enlandwhichwill haveadegreeof
chemical resistance and resistance to wear by flowing particulates or debris app~ op, iate to the
stream in which the support member is to be immersed, while being relatively ine-~er,sive and
easy to machine.
Where it is desirable to account for or regulate insofar as possible the
temperature at the interface of the tubular membrane and a given flowable material (and thus
thepermeation/l.~r,srercharacteristicsassociatedwiththatte",pe.dl.lre),thenthesupport
member will be constructed of a thermally conductive material having the desired other
characteristics. Where it is desired to simply account for le-npe,al.lre effects, a te",per~ re
20 monitoring device (e.g., a thermocouple or known le~ telllpè.dlure device (RTD)) is
positionedwithinthesupportmemberwl,èrëbytheté",pe-alureoftheconduiVstreamor
aggregation il lLel ~ce may be measured by thermal conduction from the supporting groove
portionofthesupportmembertothe~e,npe.al.Jre",or,;lvr;ngdevicecontainedwithinthe
support member. Where temperature regulation is desired, one or more heaters (for example,
25 cartridge heaters) are additionally placed within the thermally condunive support member.
In those devices wherein a small sample stream or agy, egalion is Opel aled upon,
ithasbeenpossibleinthepastton,or,ilorandregulatethete."po~allJreofthesamplestream
orayyleydlionandtothusmonitorandregulate~indirectly~thetélllpeldlureatthetubularmembrane/fluid interface. Obviously this is not going to be a very practical approaLI, in the
30 context of directly inserting a sample probe into most process streams of interest. And even in
the context of a small sample stream (or sli,c,llealll) or agg, eydlion, thermal conditioning of
theentiresamplestreamoragg,egalioncanbeeneiyy inlen~h~eandtrolJbl~some,for
example in causing degassing or precipitation of other soluble species in the stream or
agy, egdlion.
The provision in a grooved support ."e.,~ber of tê.npèrdlure monitoring devices
and cartridge heaters enables a more direct and efficient measu~e",ènl and control of
temperatureandof lldllspvllcharacteristicseveninmuchlargerstreamsorag9rëydlionsof
flowable materials, sothatanalytical data can bê plO~uelly i~ler~u~eted orthe lran~pol l
-12-
~'
38,974B-F
parameters changed for differing circur",lances and uses. The p(esence of one or more heaters
also permits a useful, periodic bake-off cycle to drive off less volatile materials which might
coatthe conduiVmembrane overtime.
There may be situations where temperature n,ohilG, ;ng only is desired; in theses
5 situations, a si ngle well can be drilled i n a grooved support member of the type described
above from the second, external end of the support ",e",ber toward the first, internal end of
the support member. Preferably the well extends substantially over the entire length of the
support member. Any suitable temperature measuring device can be placed in the well, for
example a ll,er",ocouple or other know resistive tempê(dlure device (RTD). Where some form
10 oftemperaturecontrol isdesiredinadditiontote,npelalure-"oni~G,ing,oneormorewellsof
a like nature are p,ere,dbly drilled in the support ",e",be~, and cal llidge heaters orthe like
placed therein which are RTD-controlled.
A particular, further use of the yl oo~/cd support members and associated conduits
described herein can beviewed asa corollarytotheslip,~.~zmmowcell ar,an~e",entand
method of use, and relatestothe use of such appa-dlus in bench-scale analytical work rather
than in drawing samples from a process stream, for example, wherein the sample sparger of a
conventional purge and trap device is replaced by a grooved support and associated conduit
andespeciallya9roo~edsupportwithinternallêmpeldluremorl;lol;n9andheating~ By
heating the support "~e",ber and membrane carried lhè~eGn to a suitable temperature,
20 volatile organic materials can be quantitatively rel"oved, for example, from a v ~ ev~ -Ler or
outfallsampleandanalyzedonanassociatedgas.l,ro",alug.a~,l,asincon~/e.,lionalpurgeand
trap operation.
These grooved support n~e. ~ Ibel constructions described thus far can (as
mentioned previously) also be used to effect separalions in other co- ,le.~ls, e.g., fluid drying,
25 wherein a species is selectively removed from a fluid flowing within the membrane lumens,
ratherthanbeingselectivelytranspG,ledintothelumensfromastreamoraggregdliononthe
outside of the ,r,e. "b(ane.
In general terms, a membrane-based fluid sepa, alions a~,pardlus of this type
comprises an outer vessel or outer vessel a~se",bly having an opening defined therein, a
30 grooved tubular "~e. "b,dne support " .e. nbe~ inserted through and secured in the opening,
and a tubular membrane supported in the groove in the probe "~e."beer and defining first and
second ends which can be placed in fluid communication with a source of a fluid from which a
species is to be selectively removed and a desired destination for fluid from the me.~.~ranê,
I è~p2.li-/ely.
Ap.e~e.,edconstructionisshowninFigurel2,v,/l,êrè;ntheapparatust14
comprisesanoutervesselassembly116includingahollowcylindricalmember118whichis
externallyl~"eadedatafirstend 120andatasecondend 122,andfurtherincludingadrilled-
throughtubetopipeadapterassembly 124whichxrewsxcurelyontothethreadedsecond
-13-
A
38,974B-F
end 122Ofthemember 118. Preferablytheada~lera~se,-,bly 124andthecylindrical ",e,nbe~
118 form a gas-tight seal via an 0-ring 126 orthe like disposed between the adapter assembly
124 and the cylindrical member 118.
Theoutervesselassembly116through",e."ber118thusdefinesafirstopening
128atthefirstend 120Ofmember118andoftheassembly116,andthroughanopening 130
forthe "tube" inthetubetopipeadapterassel"bly 124definesasmallersecondopeningatasecond end 122 of the assembly 116.
A ~er ,ovdble, internally-lhreaded end cap 132 screws securely onto the threadedfirst end 120 of the member 118, and like adapter a,sembly 124 at the second end 122
preferably forms a gas-tight seal with the member 118 via an O-ring 134 or the like disposed in
end cap 132.
Wheretheapparatus 114isusedforexampleasafluiddryer,ap(erer,edsolid,
flowable drying agent 136 (for example, granular calcium or magnesium sulfate) is contained
within the outer vessel assembly 116 (colll~ sing the hollow cylindrical member 118 and
adapter assembly 124) by end cap 132, and can be simply and quickly removed from the
assembly 116 by unscrewing and removing end cap 132 from the first end 120 of member 118.
Toprovidethemembraneinle-ra.ewiththedryingagent 136,agroovedtubular
membranesupport",ef"berl38(whichmaydesirablybeofthetypedepictedinFigures5-7
and 10,andwhichmaybefurthermodifiedtoincludete")pe~al,Jre",or,iLGringand/orheaters)
20 is inserted through and secured in the second opening 130 as the "tube" in the drilled-through
tube-to-pipe conne~lion offered by adapter a,se",bly 124, with the "pipe" in this case being
the hollow cylindrical ,ne",ber 1 t8.
The support member 138 is ,oosse~d of a generally cylindrical, smooth shoulder
portion 140. Toholdthemember138inplaceinthesecondopening 130,then,opposed
25 closely-fittingcollar"~e."bef,142and 144areplacedaroundthesmoothshoulderportion 140.
Theuppermostcollar",e",ber142isofthesplit-ringtype,sothatonscrewingmembers146,
148and 150tightlytogeli,el themembers 142and 144su~ )OIled ll,e,el,al~veenare
compressed and the uppermost member 142 co" "., e,ses the smooth shoulder portion 140 at its
peri phery. Those ski l led i n the art wi l l recoy, .i e ho J~e~u that other ferrule arrangements
30 could be used for holding the member 138 in place in the manner just described, depending on
the intended application of the present inventive ap,oaralus (i.e., high pressure applications
versus low pressure applications).
Thoseskilled intheartwill also.a.~y"i.ethatotherconsiderablydirre,en~
constructions could be employed for placing the support ",e,.,be(138 in the hollow cylindrical
35 member 118. For example, threads could be pro~ided on the shoulder portion 140 of a
member138,andthe"~e",ber138 joinedtotheasse,nbly116viaathreadedopeninginanend
capatthesecondend122Ofmember118,withtheendcapinturnbeinginternallylhreaded
and screwed onto the ",efnber 118 at ik second end 122. Alle~al~ y~ the end cap and
-14
s
38,9748-F
_ member 118 in such an embodiment could be consolidated into a hollow cylindrical outer
vessel having a first end like the first end 120 of dryer 114, but having a second end which is
dosedbutforasmallerthreadedopenin9lh~éLll;oughinwhichthemember138canbe
inserted and secured.
In still other embodiments which may be app- opriate for particular applicationsand uses of the apparatus 114, the support member 138 could be dedicated to this use and
glued, welded or ull .elv~ise affixed in an opening in an end cap, an adapter assembly or in the
closed second end of an outer vessel. Still further, it may be app~ O~GI iate in some circumstances
toeliminatetheendcap132Overthefirstend120Ofthe--,e..-ba~ 118,whileprovidingan
10 opening in an ~.~helv~ise closed second end in which the ~..e-nber 138 can be permanently
affixed. The device would then be constructed essentially like an oil filter, and would be
disposed of as a unit.
Inthep-ere--edembodimentoftheappa-dlusshowninFigure12,theapparatus
114havingasoliddryingagent136incGr~.Grdledthereinisfurthercomprisedofmeansfor
purging unJ/an~ed al~"Gs~heric gases from the outer vessel asie. nbly 116 at least prior to
placing the apparatus 1 14 in operation, so that a high purity of dry fluid delivery may be
obtained from the appardl.lsldryer 114.
This purging means may be in the form of septa needle ports, for example, or mayas shown in Figure 12 be in the form of Sw~ typê tube-to-pipe male conne~Gr, 152
20 v,~hefëby a flow of a dry purging gas may be communicated to and from the assembly 116.
Cor,e,,uonding flows of a purge gas into and from the dryer 114 are .~presenLed by arrows 154
and 1 56"e,,~.e~li./ely. In other, prefe. Ied e.nbvd;,--a--ls, the cvnne~lo-, 152 are coupled with
valves for blocking offthe assembly 116 after a purging of the as;~ bly 116 has occurred. The
dry purging fluid could have a separate source, or could simply and prefé.~bly comprise a
25 portion of the dry fluid proceeding from the dryer 114. Where a flow-through dessicant is to
be employed, of course, the conne~lGrs 152 could serve as an appfo,G ~ iate entrance and exit for
the flow-through dessicant.
While much of the foregoing description has focused on use of the appardlus 1 14as a fluid dryer, as has previously been sug~->led other applications are equally possible
30 whereinaspeciesisselectivelyremovedfromafluidviaame..~brd.)e 158. Thoseskilledinthe
art will be well able to conceive of a number of such applications. For example, the selective
removal of a,-"Y~onia from a gas could be accG,--,~)lished by using a silicone rubber membrane
surrounded by an absG- L~nl packing of ~l ~arcoal or a material ~héllli ally reactive with
ammonia, for example a low vapor pressure, phGs~ G. ic acid solution which would form
35 ammonium phGsphd~e with the ammonia. Carbon dioxide could be selectively re.~vJ ad from a
gas by surroundi ng the ."e.nbrdne with Ascarite~ sodium hydroxide-coated silica from Union
Carbide, which scd~l_nges carbon dioxide selectively and reversibly. As a further example,
-15-
,~
1~ ~
38,974B-F
--oxygen could be re.no~ed from a fluid by surrounding the membrane with barium metal
catalystthatirreversiblyreactswiththeoxygentoform bariumoxide.
Another possible application of the grooved support members is illustrated in
Figures 13-15. This application has been briefly mentioned herein previously, and relates to
5 self-contained gas chromatographic appardl.ls or self-contained, portable gas
chromatographic appara~us.
The electrolytic hydrogen carrier gas genèldlor employed therein can be broadly
described as a membrane-based microele-lroly~:, cell of negligible internal dead volume, and
allowspressureandflowcontrol overthegene.dlèd hydrogencarriergasviacontrol overthe
10 electrolysis current supplied to the cell. The rate of hy~lfogen carrier gas production by the
geneidlorwill9enerallybematchedtomeettherequi~ enlsofacapillarycolumn~e~9~from
about 2 to about 8 cubic centimeters per minute at dl,..o"~he. ic pressure or a pressure just
slightly above atmospheric and at ambient telllpe,dlures of about 20 degrees Celsius.
The gene(d~or is illustrated in a p~e~el,eJ embodiment 160 in Figure 13, and
comprises an inverted T-shaped member 162 defining a central cavity 164 therein for
containing the fluid to be electrolyzed to produce the hydrogen carrier gas, with such fluid
preferably comprising simply an eiectrolyte in distilled or de;oniL~d water. A threaded cap 166
at the top of the member 162 is removable to allow water to be added when necessary.
On either "arm" of the inverted T-shaped ,.-ombe, 162 are electrode/memb(ane
20 assemblies 168 and 170 which employ a cation ex.l,ange membrane 172 and anion exchange
membrane 174" especli~rely. These assemblies 168 and 170 are essentially mirror images of one
anull,ar,andcomprisefromtheinteriorofthe.ne..,bër 162Outv,/ardaporoussupport176
which may suitably be constructed of a poly(vinylidene fluoride) material, the cation e,~.hange
membrane172Oranionexchangemembrane174,aplatinumwiremeshelectrode178,a
25 porous but h~ ophûbic film 18o which can suitably be poly(tetrafluoroethylene)~ and a second
porous support 182 which can be identical to the support 176.
Plug members 184 contain the assembliff 168 and 170 in position, and can be
removedforreplacingoneormoreelementsoftheassemblies168and 170asnecessary.
Where gas leaks develop, for example, because of the co-- .pa, dli~l_ rigidity of an exchange
30 membrane, a fluoroelastomeric gasket (not shown) can optionally be in-el ,uosed between the
support176andtheadjacentexchange,-,e-~,b.ane1720r174. ~le-l~icalcûnl~e~lion~et~eena
voltage source (not shown) and the wire mesh ele-l-odes 178 is provided through holes 186,
while tubing for collecting and conveying the gene,dled l)"drogèn and oxygen is joined tû thê
plug ",e",be,~ 184via holes 188.
A general schematic is provided in Figure 14 for a self-contained or self-
contained, portable gas chromaloy, dpl~ic appdldllJs 190 constructed according to the present
i nvention. A "-e-, ,b, ane-based microelê~lroly;;s cell 192 gene(dles high purity hyJ, ogen and is
chara~le,i~edbynegligibleinternaldeadvolumê,withap-erelledembodimentofthecell 192
-16-
~8,9748-F
~_ being the embodiment 160 shown in Figure 13. In combination with the carrier gas gena,dlor
192areafluiddryer194whichispreferablya.,.e...brdne-basedfluiddryerandespeciallyamembrane-based fluid dryer of the type described in conjunction with Figure 12, a sample
injector or other sampling device 196, a capillary GC column 198, and a detector 200.
It should be noted that the fluid dryer 194 of this self-contained or self-contained,
portable gas chromatographic appardllJs is not strictly limited to nte.,.brdne-based devices,
even while a membrane-based fluid dryer as shown in Figure 12 is especially ,orerer,ed because
of its ease of use, cc.,~-pa.l, le~, and capability of drying the required volumes of a carrier gas
without ad~m~ely arre-ling the purity of the carrier gas.
Forexample,ithasbeenknowninthearttoseparatel.~drogenwithahigh
degree of selectivity from other gaseous impurities (e.g., H20, ~2) by flowing the hydrogen and
accompanying impuritiesthrough a hot palladium tube. Itshould thus be possible in the
apparatus 190toemployagenê.d~o(192,ahotpalladium h~l irogensepardlor/d~er 194andp,~:re(ably a separate fluid dryer 194 (which may suitably be as shown in Figure 12) for oxygen
gene, dled in gene- alor 192 via the ele.l,oly~:i of a fluid con.pfi,ing an electrolyte in distilled or
deionized water. Those skilled in the art may be aware of still other devices which could be
used to separale generdled hydrogen in high purities from other products of or materials from
the electrolytic gene,dlion of hydrogen, and it is cori,idenëd thatthese devices may be suitable
as well.
A, ecG- der 202 associated with the dele.lo~ 200 may be located with the other
elements, or preferably will be lemotely located and will receive data from the detector via
telemetryorthelike. Thesampleinjector196,column198,dek~lor200andrecorder202can
be those conventionally employed in the previously-known self-contained or self-contained,
portableGCappa,dl,Js,andinparticulartheGCap,vdrdlusofthepresentinventioncanemploy
25 any conventionally known detector, for example a thermal conductivity detector, an electron
capture detector, a photo ionization detector, a chemiluminescence detector, a Hall electrolytic
conductivity detector, a flame ionization detector or a combination of t~,vo or more of these.
A pi ere"ed embodiment 204 of a self-cc.nld;ned or self-contained, portable GC
apparatus is schematically illustrated in Figure 15, and includes an ele~lrolytic hy iros~en carrier
30 gasgenerator160asshowninFigure13withafluiddryer114asshowninFigure12.
Automated analysis of a sample 206 is enabled by a cc n.l_nlional, co...,.,ercially-available
sampling valve 208. The hydrogen geneldted bythe gene,dlor 160 and dried in fluid dryer 114
serves as a carrier gas, and along with the oxygen yenel dled in yenerdlor 160 serves also as a
detectorgas,fore,.d..l,~'~,foraflameionizationdetector(FlD)210. All~",ali.~ely,someorall
35 of the hydrogen and oxygen for the FID could be produced by a second gene. dlor 160.
The sampling valve 208 can draw directly from a procffs stream to be analyzed, or
in a ,l~rere. red variation on the illustrated embodiment 204 can draw from a separale
,..e-.,b-dne-based sampiing device of the dffign shown in Figures 5-7 and 10, with such device
-17-
., ..-.,
~ ~
38,9748-F
' ~ possibly including internal te-.,peid~ure ,..or.ilo. ing andlor heating elements. In still another
variation the sampling device of Figures 5-7 and 10 (equipped or not equipped with internal
heaters, ~her..,ocouples, etc.) can be used in place of the sample loop of a conventional
sampling valve 208.
An additional feature of the p~ere. -ed embodiment 204 is the use as a capillary
columnsupportofay~u~J~dsupportln~:lllberofatypedescribedabovewhichhasbeen
equipped with internal heating and te.np~.dlure ~nor ilc.ring means, with the 9, oo~ed support
member design of Figures S-7 being espe-i~11y ~"~re"~d. The y~uOJ~ support member
providesaconvenientlycompact, te..,pe.alure-controlledsupportfortheotherwise
10 conventionalcapillarycolumn 198Ofapparatus204.
The foregoing clearly is indicative of the versatility of the present technology, but
as clearly is not an exhaustive treatment of the possible applications and uses of the
technology.
Several aspects of the present invention are further illustrated in the following
examples:
Example 1
Trace levels of chlGror~r-n (about 0.1 to about 1.0 parts per million by weight)were found to be present in a hot (50 to 60 degrees Celsius) aqueous plant stream containing
from 2 to 3 weight percent of hJdf~. hIGr;C acid and su,pended particulate matter.
For this example, a co-n~,arison was made t~~e_n a stream analysis as
pe,ro----edbyalabG.d~o"~purgeandtrapinstrumentsetupinaccordancetoUnitedStates
Envi ronmental Protection Agency ~e ll ,ocl 601/602, "Analysis of Volatile Organics i n Water",
andananalysisaspe,ru,---edbyaprere"~d,valve-ins~,lableap~.aralllscor-~jpondingtoFigures 5-7 and 10 in combination with a c~ .,lional laboralo~ y gas chromatograph.
The valve-insertable apparatus forthis ~al- .ple employed a silicone rubber
capillary membrane. The ~..e...brane length was 1.83 meters (six (6) feet) and the membrane
had an outside diameter of 0.635 mm (0.025 inches) and an inside diameter of 0.305 mm (0.012
inches), for an effective internal volume of about 0.1 ml. The ."e..,~rane was coupled to a
conventional labGral~"~gaschromatG.a,apl.via0.3mm(1/8inch)stainlesssteeltubing,and
30 the apparaluswasfully i.n,.,e,sed in the processstream through an open trough, using a 1.83
meters-long (six (6) feet) piece of 2.5 cm. (1 inch) piping as a stinger.
lrogen was circulated through the central lumens of the men ,~rane at 6 cubic
centimeters per minute, and carried to an automated sample valve. The sample loop was
iniectedontothechromalùylaphiccolumn~andstreamc~lllpGnelll~weresepar~ledand
35 qua,-lilaled on a flame ionization detector.
Samples for the purge and trap analysis were captured in liquid-full, virgin glass
bottles with polymeric seal tops. The fresh s~ les were plunged into an ice bath and
-18-
~F~
s
A"-~
38,974B-F
,an,pG, led immediately to the site of the purge and trap apparal.ls, whereupon the samples
were loaded directly into the purge and trap auto-sdmpler and analyzed.
Figure 16 shows the quanli laLèd levels of chlorofo, ~.. obtained by purge and trap
analysis and by an apparalus of the present invention, and suggoctc that on-line analysis using
5 the sampling apparatus of the present invention should be an acceplable alternative to the off-
line and significantly more inconvenient purge and trap analysis suggc,led by the United States
Environmental Protection Agency (EPA).
Example 2
An azevl-ope was formed in a process stream between 1,3 butadiene and trace
10 levels of acetaldehyde and acetone. To remove these trace level impurities and permit ~eco~e. y
of the 1,3 butadiene, it was proposed to contact the crude 1,3 bulddiene process stream with
water, wl .e.eby the ~art,Gn~tl containing impurities could be e~ d~èd into the aqueous phase.
Conventional direct analysis was dllelll~led (at 0.48 N/m2 (70 Ibs.) of prffsure and 60 degrees
C.) in a convenlional on-line gas chromdlug- dph of the crude and purified 1,3 butadiene
process streams to ,..or.ilor and control the extractior~epa-dlion, butwas plagued with
pluggingandfoulingproblemsduetopoly,.-e,iLdlionofthe 1,3butadieneandthepresenceof
coke-like particles.
A capillary membrane-based sampling apparalus of the present invention was
constructed asshown in Figures 1~and asdes..;bed herein, butratherthanthesilicone rubber
20 membrane of Example 1 employed a Teflon'' FEP copoly.,-e, ~--e.-~b-anctubing (1.83 m (six (6)
feet) long, 0.635 mm (0.025 inch) o.d., 0.305 mm (0.012 inch) id., 0.1 ml internal volume). The
probe was employed in a flow cell appardllls of the type shown in Figure 11, and an emulsified
slip~lrealll of water and 1,3 butadiene (essentiallywater-saturated 1,3 butadiene) was passed
through the flow cell. r: l, ogen gas, flow controlled at 6 cc/min., was continuously circulated
25 through the probe and delivered to a sampling valve in a gas chromalGg- aph as in Example 1.
The sample loop on the sampling valve was in;e~led onto the column of the GC, and sepa"lled
and enabled the quantification of the 1,3 butadiene, a~e: ~dehyJe and acetone in the crude
and purifled process streams as shown in Figure 17.
ExamPle 3
Anincomingwastestreamtoabiologicalwa~ ~erlrealll~entfacilitywasa
potentialsourceofben7ene,atightly,ue.---illed,essentiallynon bi~deg adablepollutant.
Withthedilutionfromotherincomingwasl~J/~terstreams,itwasdeterminedthatthe
concer-l,dlion of benzene in the particularwaste stream should not exceed 2 parts per million
by weight.
A capillary . ne~ . ,b, dne sampling device was constructed for this example as in
Figures 1-4 and as in Example 2 above. This device was inserted through a 15.2 cm (six (6) inch)
gatevalvedirectlyintothewastestreamfor.-lonilo.ing(withacûn~e.llional gas
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"~ chromd~og,~ph)thelevelsofbenzEnEtherein. Figure18showsthe~oncen~,dlionsofbenzene
in the waste stream over a two day period of such ",on;Loring.
An excursion in the benzene level of the stream was obse, ~/~d at between 21 and26hours,withtheprobeandassociatedGCtrackingtheriseinben~eneconcenl,aLion. The
5 plant producing the waste stream was notified, and at 27 hours the source plant fe"~oJed all
possiblebe..zenesourcfftothestream. The~enzeneconce..l-aLionlt.eredrl~:rwasobserved
to fall to near zero. At 31 hours, the source plant i.lfor...Ed W_~t~J ~lertreatment plant
pcrsonnel that the upset had been diaynosed and cor-~led, and the various flows into the
waste stream were resumed. The .ne",b-~-ne sampling probe and associated gas
chrom~lloy, aph subsequently confirmed the levels of l~en~ne as returning to app, op, iate
levels, indicating thatthe problem had indeed been remedied atthe source plant.
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