U.S. patent number 3,662,928 [Application Number 05/025,736] was granted by the patent office on 1972-05-16 for fluid sampling device.
This patent grant is currently assigned to Louis August Pogorski. Invention is credited to Louis A. Pogorski, Ernest M. Reimer.
United States Patent |
3,662,928 |
Pogorski , et al. |
May 16, 1972 |
FLUID SAMPLING DEVICE
Abstract
A device for the collection, storage or transfer of fluids
comprising two thin, metallic inherently stable shells each of like
shallow dome-shape contour joined at their basal abutting edges to
define in internal cavity isolated from the atmosphere, at least
one of said shells having an inherent spring-like flexibility such
that under the application of an externally applied force it is
displaceable without rupture from the cavity defining relation of
maximum volume to a second stable position of an inverse uniformly
dome-shaped contour with the other of said shells in cavity
defining relation of minimum volume, and reversely, and passage
means integral with at least one of said shells for establishing
fluid communication with said internal cavity.
Inventors: |
Pogorski; Louis A. (Toronto,
Ontario, CA), Reimer; Ernest M. (Toronto, Ontario,
CA) |
Assignee: |
Pogorski; Louis August
(Toronto, Ontario, CA)
|
Family
ID: |
21827788 |
Appl.
No.: |
05/025,736 |
Filed: |
April 6, 1970 |
Current U.S.
Class: |
73/864.11;
222/211; 604/212; 600/576; 600/580; 222/214 |
Current CPC
Class: |
G01N
1/24 (20130101); G01N 1/14 (20130101) |
Current International
Class: |
G01N
1/14 (20060101); G01N 1/24 (20060101); B65d
037/00 () |
Field of
Search: |
;222/206,211,215,214,464,444,92,207 ;220/4E,23,5A
;73/421.5,425.6,426,429 ;141/1,2,68,77,114,18,10,67,313,337
;128/230,231 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Coleman; Samuel F.
Assistant Examiner: Slattery; James M.
Claims
What is claimed is:
1. A device for the collection, storage or transfer of fluids
comprising two thin, inherently stable walls each of like shallow
dome-shaped contour joined at their basal abutting edges to define
an internal cavity of maximum specified volume isolated from the
atmosphere, each of said walls having an inherent spring-like
flexibility such that under the application of externally applied
forces each wall is displaceable without rupture from a first
stable position with the other of said walls in cavity defining
relation of maximum specified volume through an over center
position to a second stable position of an inverse uniformly
dome-shaped contour with the other of said walls in cavity defining
relation of minimum specified volume, and reversely, and passage
means integral with at least one of said walls for establishing
fluid communication with said internal cavity.
2. A device according to claim 1 in which said walls in said stable
positions in cavity defining relation of minimum specified volume
abut each other substantially throughout their areas.
3. A device according to claim 2 in which the basal abutting edges
of said dome-shaped walls are circular.
4. A device according to claim 3 in which the value of the basal
diameter to the maximum separation of the apices of said
dome-shaped walls is greater than 4.
5. A device according to claim 4 in which said dome-shaped walls
have a common axis of symmetry.
6. A device according to claim 4 in which said dome-shaped walls
are each comprised of a thin sheet of stainless steel.
7. A device according to claim 6 in which the thickness of each
sheet of stainless steel is less than 1 times the diameter of said
dome-shaped walls.
8. A device according to claim 1 in which said passage means for
establishing fluid communication with said internal cavity
comprises a capillary tube extending through at least one of said
dome-shaped walls and having a portion thereof extending outwardly
beyond said dome-shaped wall.
9. A device according to claim 1 in which said passage means for
establishing fluid communication with said internal cavity
comprises a capillary tube arranged to extend between the basal
abutting edges of said dome-shaped walls and having a portion
thereof extending outwardly beyond said edges.
10. A device according to claim 8 in which said capillary tube is
deformable throughout a portion of its length whereby said internal
cavity can be hermetically sealed from the atmosphere.
11. A device according to claim 1 in which said passage means for
establishing fluid communication with said internal cavity is
defined by an aperture extending through at least one of said
dome-shaped walls.
12. A device according to claim 1 in which the total minimum
specified volume of said internal cavity and said passage means is
of the order of 0.5 percent of the total maximum specified volume
of said internal cavity and passage means, or less.
Description
This invention relates to a novel device useful for the sampling or
collection of a fluid, the storage or shipment of the collected
fluid sample, or the transfer of the fluid sample all in an
efficient, safe, leak-free and substantially contamination-free
manner.
More particularly this invention relates to a novel device for
taking a measured sample of gas or liquid in a quantity sufficient
for gas chromatographic, mass spectrometric or other applicable
types of analyses, which device can be hermetically sealed to
isolate contained fluid samples for storage or shipment or used for
the transfer of the measured sample of gas or liquid to suitable
testing apparatus or into any system by utilizing simple techniques
dictated by the structure of the device itself, all in an
efficient, safe, leak-free and substantially contamination-free
manner.
Rapid growth of technology in the fields, amongst others, of
chemical process industries, earth sciences, environmental studies,
and medical sciences, has created a pressing demand for efficient,
accurate and economic sampling and analyses of fluids from a
variety of sources. In many projects not only are the major
components of the fluid to be identified and a quantitative
analysis reported, but also it may be necessary to establish the
concentration level of trace components. Other demands may call for
safe, contamination-free and leak-free storage of a collected
sample or the collection and transfer of valuable or dangerous
fluids for the purpose of further processing or for direct
application of such fluids to a system.
The amount of fluid required for the purposes outlined is usually
rather small. In general less than a few cc's (NTP) of a fluid
sample are required for gas chromatographic analysis. An even
smaller sample is adequate for mass spectrometric and other types
of instrumental analysis now available. Fluid quantities of the
same order are suitable for injection of reactants or labelling
compounds into process equipment, or for injection into human or
animal tissues.
Analysis of a fluid usually can be carried out with satisfactory
precision once the fluid sample has been transferred to the
analytical apparatus. The reliability of the analytical results,
however, depends not only on the precision of the measurement
obtained with the analytical apparatus, but on the quality and
quantity of the sample collected, preserved, and transferred.
Unless the collection of a sample, its storage or transfer into the
inlet system of analytical equipment are carried out in a
substantially contamination-free, leak-free, deterioration-free and
in a reproducible manner, the results will be unreliable or of
little or no value.
Representative contamination- and deterioration-free collection,
preservation and transfer of fluid samples into the analytical
systems still present serious technical and economic problems. This
is particularly true if volatile samples are involved and trace
analysis is desired. In many cases, samples cannot be fed directly
into the analytical apparatus because the technical and/or economic
considerations make location of the necessary apparatus at the
sample source, or placing of the sample source close to the
location of the apparatus, impossible or impractical. In such
cases, collection of the samples in suitable containers for
transfer to a laboratory for analysis represents the only practical
way of approach. Many of the chemical process samples,
environmental, geochemical and medical samples fall into the above
category.
Known devices used for collection or storage or transfer of fluid
samples for the purposes outlined, prior to this invention include
the following:
a. glass collecting tubes or containers equipped with one or two
stopcocks;
b. metal cylinders or tubes equipped with one or two valves;
c. glass containers equipped with breakseals;
d. piston-equipped syringes made of glass, metal, plastic or a
combination of such materials;
e. bellows made of plastics, rubber or metal.
In order to collect a representative sample, the known devices of
fixed volume must be properly purged or evacuated prior to the
sample admission.
Purging of a container is a tedious operation. Fluid pockets in or
around the valves, stopcocks or container ends are difficult to
remove and tend to contaminate the contents. Large volumes of fluid
to be sampled are used up for the purging operation. This method
is, obviously, not suitable when the amount of the fluid to be
sampled is small.
Evacuation of the known devices presents difficulties. On-location
evacuation requires relatively complex equipment and is time
consuming. Pre-evacuation may be only partially effective on
devices employing valves and stopcocks. The preservation of a
vacuum or of a stored fluid for an indefinite period of time is
difficult to achieve, if not impossible.
Transfer, and in particular quantitative transfer, of a sample kept
at the given charge pressure inside a storage container into the
inlet system of the analytical instruments or into other systems
operating, in general, at the pressures different to that of the
given pressure of the sample presents still other disadvantages.
Auxiliary equipment and complex time-consuming procedures subject
to many errors are required to effect a satisfactory transfer.
The syringes or bellows-type devices overcome some of the
disadvantages while posing others. The main disadvantages of the
syringe-type devices are that they leak and that the seal on the
piston presents adsorption and contamination problems. A permanent,
hermetical seal at the piston is not possible. Such devices cannot
be used for storage of the samples for indefinite periods.
The main disadvantage of the bellows-type devices is the relatively
large dead volume of the convolutions. The purge requirements and
the poor reproducibility of the sample transfer operation caused by
the dead volume and by a rather limited capability to collapse make
this type of device unsatisfactory for many applications.
It is therefore the principal object of this invention to provide a
device which greatly simplifies the task of collecting and
transferring fluid samples for testing purposes or otherwise, and
that may be used, if desired, for storing a collected fluid sample
for an indefinite period of time without leakage, all in a
substantially contamination-free manner.
More particularly, it is the principal object of this invention to
provide a device that may be used for collecting a fluid sample
from a source at atmospheric, sub-atmospheric or above atmospheric
pressures, for storing the collected fluid sample for an indefinite
period of time without leakage and deterioration and from which the
collected fluid sample can be discharged into a system at
atmospheric, sub-atmospheric or above atmospheric pressures, all in
an efficient, safe and substantially contamination-free manner.
Still another important object of this invention is to provide a
device of the character described, which is inherently adapted for
collecting, storing and transferring a fluid sample in a
quantitatively accurate and reproducible manner.
Still other important objects of this invention are to provide a
device of the size that may be readily employed as a hand
instrument, simply yet strongly constructed so as to be capable of
easily withstanding the normal hazards of handling or shipping and
which can be economically manufactured.
The principal feature of this invention resides in providing a
device in which the walls of the fluid container portion are so
shaped and at least one wall possesses such inherent resiliency
that under the application of directed externally applied forces
the inherently resilient wall is displaceable without rupture
whereby the configuration of the container portion can be
selectively converted from one inherently stable configuration
enclosing a maximum specified volume to a second inherently stable
configuration enclosing a minimum specified volume, and reversely,
the vacuum created by the conversion of the container portion from
its stable configuration enclosing the minimum specified volume to
the configuration enclosing the maximum specified volume serving as
the driving force to draw in a fluid sample and the reduction in
volume by conversion of the container portion from its
configuration enclosing a maximum specified volume to its
configuration enclosing the minimum specified volume serving to
expel the fluid sample therefrom.
More particularly, it is a feature of this invention to provide a
device of the character described in which the container portion
can be substantially completely collapsed, thereby reducing the
minimum specified volume to a negligible quantity.
Still another important feature resides in providing a device of
the character described in which the dimensions of the fluid
container and wall thicknesses have been selected such that the
container can be converted from one stable position to the other
and reversely under finger and thumb pressure, and thereby serve as
a hand instrument.
Still another feature of the invention resides in providing a
device of the character described, in which the fluid inlet-outlet
passage formation is in the form of a hollow needle or capillary
tube, which may be suitably sharpened at its external tip for
insertion into the septum of a system from which a fluid sample is
to be drawn or into the septum of the inlet system of analytical
apparatus into which the fluid sample is to be injected. Further
the capillary tube may be so conditioned if necessary, throughout a
portion of its length that it is susceptible of deformation by
crushing to seal the contents of the container for storage or for
shipment and then severed and sharpened if necessary, when it is
desired to expel the contents.
These and other objects and features will become apparent in the
following description to be read in conjunction with the
accompanying sheet of drawings wherein
FIG. 1 is perspective view on a slightly enlarged scale of the
preferred embodiment of a device made in accordance with the
invention showing the container portion in its stable configuration
enclosing the maximum specified volume;
FIG. 2 is an enlarged vertical sectional view of the device of FIG.
1 taken along the line 2--2 of FIG. 1;
FIG. 3 is an enlarged vertical sectional view of the device of FIG.
1 with the container portion thereof shown in one stable
configuration of its collapsed state;
FIG. 4 is an enlarged vertical sectional view of the device of FIG.
1 with the container portion thereof shown in the other stable
configuration of its collapsed state;
FIG. 5 is a perspective view of an alternative embodiment on a
slightly enlarged scale made in accordance with the invention with
the container portion in its stable configuration enclosing the
maximum specified volume, partly broken away.
In the preferred embodiment illustrated in FIGS. 1 to 4 it will be
observed that the device made in accordance with the invention
comprises a capsular container portion 10 provided with a fluid
inlet-outlet in the form of a capillary tube 12.
The walls 14 and 16 of container portion 10 in the preferred
embodiment are identical. Each has a peripherally flattened basal
edge portion 18 and 20 respectively and a shallow dome-shaped
configuration 22 and 24 respectively. Each wall 14 and 16 may be
formed in a suitable die from a sheet of suitable metal, or metal
alloy, preferably a sheet of stainless steel, the properties of
which are particularly suited to the conditions normally
encountered in the use of the device and possessed of
characteristics essential to the successful operation of the
device.
The abutting edges of walls 14 and 16 are edge welded together as
at 26 throughout their peripheries adjacent their basal edge
portions 18 and 20 to provide a strong hermetic seal in accordance
with known welding procedures.
In the embodiment illustrated in FIGS. 1 to 4 the capillary tube
12, preferably made from stainless steel, is provided with a
sharpened external tip 28 with the opposite end 30 disposed within
a channel defined by depressions 32, 34 in the basal edge portions
18 and 20 of the walls 14 and 16. Capillary tube 12 is anchored
within the channel by welding or in any other suitable manner to
establish a strong hermetic seal.
In the preferred embodiment illustrated the peripheral outline of
each wall 14 and 16 is circular. Further the dome-shaped contour of
each wall is quite shallow and preferably symmetrical about a
common central axis 38.
In FIG. 2 the separation of the dome-shaped walls 14 and 16 in the
stable configuration of container portion 10 enclosing the maximum
specified volume is designated H and the diameter of the container
portion 10 is designated D.
It has been demonstrated that by forming each wall 14 and 16 from a
sheet of stainless steel having the following specifications, SS
301 spring temper 0.010 inch, and by selecting a diameter D of the
order of 2 inches and by selecting a shallow dome-shaped contour
such that the separation H is of the order of 0.2 a container
portion 10 of maximum specified volume of the order of 2.5 c.c. can
be provided sufficient for the sampling of fluids for gas
chromatographic analysis or mass spectrometric and other types of
instrumental analyses and for various other uses.
Further it has been established that where the value of D/H is
greater than 4 the container portion 10 can be converted from the
apparent inherently stable configuration shown in FIG. 2 to that
shown in FIG. 3 upon the application of external forces to the
outer surface of wall 14 in the direction of the arrows 40.
Likewise container portion 10 can be converted from the apparently
inherently stable configuration shown in FIG. 2 to that shown in
FIG. 4 upon the application of external forces to the outer surface
of wall 16 in the direction of arrows 42.
According to our observation under the application of the external
forces in the direction of the arrows 40 to the wall 14 to collapse
container portion 10, the wall 14 appears to pass through an over
center position whereupon it "snaps" into a substantially inverse
uniformly dome-shaped contour abutting the surface of the opposed
wall 16 as illustrated.
Likewise upon the application of external forces in the direction
of arrows 42 to collapse container portion 10 wall 16 appears to
pass through an over center position whereupon it "snaps" into a
substantially inverse uniformly dome-shaped contour abutting the
surface of the opposed wall 14.
The application of external forces to the collapsed container
portion 10 at the edges of the container portion 10 and in the
direction of the arrows 44 shown in FIG. 3, or in the direction of
the arrows 46 shown in FIG. 4, the walls 14 or 16 as the case may
be appear to pass back through the over center position whereby
they "snap" back to their original dome-shaped contour thereby
establishing the configuration illustrated in FIG. 2 enclosing the
maximum specified volume.
It has been observed that not only is the configuration of
container portion 10 illustrated in FIG. 2 apparently inherently
stable but that the configurations of the collapsed container
portion 10 illustrated in FIG. 3 and 4, enclosing the minimum
specified volume, are also apparently inherently stable.
We have observed that a device of the character described may be
collapsed and expanded without rupture. Moreover, we have also
demonstrated that by exercising close control over the die forming
operations and the welding procedures that the container portion 10
can be converted from the configuration of FIG. 2 into the
substantially completely collapsed configurations of FIG. 3 and 4
thereby minimizing the dead volume of the container portion 10.
Having outlined the structure and operation of the device, its
utility in the collection, storage and discharge of fluid samples
will now be described.
If it is desired to take a small sample of fluid for example 1 - 10
cc, from a system operating at atmospheric pressure, provided with
a septum, first a device having a container portion 10 of maximum
specified volume of the order of 1 - 10 cc is selected. Container
portion 10 is then converted from the configuration shown in FIG. 2
to the collapsed configuration of either FIGS. 3 or 4 by the
application of thumb and finger pressure which under ordinary
conditions will be sufficient to exert the external forces
necessary or if preferred by a pressure exerted by a suitable tool
such as pliers, notched wrench or the like. The sharpened end 28 of
capillary tube 12 may then be inserted through the septum of the
system to place it in communication with the fluid source. By the
application of thumb and finger pressure to exert the external
forces necessary the collapsed container portion 10 is converted
into the expanded configuration of FIG. 2 enclosing the maximum
specified volume, the walls 14 and 16, upon separating, create a
vacuum within the enclosed space which serves as the driving force
to draw the sample through the bore of the capillary tube 12 and
into the enclosed evacuated space.
The capillary tube 12 can then be withdrawn from the septum of the
system from which the sample has been taken and then inserted
through the septum of testing apparatus if it is close by. By the
application of pressure to convert the configuration of FIG. 2 to
the collapsed configuration of either FIGS. 3 or 4 the fluid sample
will be expelled into the system of the testing apparatus.
We have observed that with a device of the character described the
reproducibility of sample collection and discharge is within 0.1
percent of container volume. Hence, where the apparent maximum
specified volume of a given device has been established one may use
such device for the collection, storage and discharge of a fluid
sample of known volume, thereby eliminating any other procedure
that would be otherwise necessary to measure the volume of the
fluid sample collected and stored or transferred.
A device of the character described, slightly modified, can also be
used to collect samples from a system operating at sub-atmospheric
or at above atmospheric pressure and transferred to a system at
atmospheric, sub-atmospheric or above atmospheric pressure in a
substantially contamination-free and leak-free manner as will now
be described.
The capillary tube 12 may be conditioned, as by annealing, or in
any other suitable manner, such that is deformable throughout a
portion of its length 48 remote from the sharpened tip 28, or close
to the tip as preferred.
In the case where a sample is to be taken from a system operating
at sub-atmospheric or at above atmospheric pressure the container
portion 10 is first converted from the expanded configuration of
FIG. 2 to the collapsed configuration of either FIG. 3 or 4, and
then the capillary tube 12 is inserted through the septum of the
system from which the sample is to be taken. Upon conversion of the
container portion 12 from the collapsed configuration of either
FIGS. 3 or 4 to the expanded configuration of FIG. 2 a sample at
sub-atmospheric or at above atmospheric pressure will be drawn into
the evacuated space. Before the capillary tube 12 is withdrawn from
the septum the deformable portion 48 of the capillary tube 12 can
be crimped with a suitable instrument, such as a pair of pliers,
thereby hermetically sealing the contents. The crimped capillary
tube 12 can then be withdrawn from the septum of the system.
The samples collected and sealed in the manner described can be
preserved indefinitely without leaks, contamination or
deterioration, and the sealed devices may either be placed in
storage or may be shipped to the laboratory in which tests are to
be carried out.
When desired, the crimped portion of the capillary tube 12 can be
ground off on a grinding wheel or severed by suitable shears,
immediately prior to its insertion through the septum of the inlet
system of the designated analytical apparatus.
In the alternative, procedures may be adopted whereby the crimped
capillary tube can be severed after insertion through the septum of
the inlet system of a designated analytical apparatus.
Container portion 10 may then be converted from the expanded
configuration of FIG. 2 to the collapsed configuration of either
FIGS. 3 or 4 to expel a metered quantity of the fluid sample
collected.
It will be readily appreciated that where it is desired to
hermetically seal a sample collected from a system operating at
atmospheric pressure a similarly modified device may be
employed.
It is contemplated that where, for example, a sample is to be drawn
into the container portion 10 from a source at sub-atmospheric
pressure auxiliary grips in the form of lever arms may be welded at
the apices of the dome-shaped walls 14 and 16 to assist in the
snapping of the walls 14 and 16 into the expanded configuration of
FIG. 2 and to maintain them in such configuration, if
necessary.
It is also contemplated that where, for example a fluid sample at
substantially above atmospheric pressure is collected it can be
expelled, if necessary, by the application of a mechanical force
exerted by the shaped jaws of a vice.
By selecting a capillary tube 12 of a very small internal
cross-sectional area through which fluid exchange may take place
contamination of a collected sample may be minimized.
We have demonstrated that in a given system comprising container
portion 10 and capillary tube 12, that if the total internal dead
volume of the container system in the collapsed configuration is
limited to the value shown in relation to the total internal volume
of the said system in the expanded configuration according to the
Table I, contamination of the collected fluid sample is minimized.
---------------------------------------------------------------------------
TABLE I
Total internal volume of the Total internal dead volume expanded
container system of the collapsed container system
__________________________________________________________________________
less than 1 cc less than 0.5% less than 1-10 ccs less than 0.3%
more than 10 ccs less THAN 0.05%
__________________________________________________________________________
we have observed that under the conditions specified there is ample
time to either grind the end of the capillary tube 12 to a needle
point or for attaching a needle-type adaptor before inserting it
into the septum of the analytical system, without appreciably
affecting the results.
It will be obvious that container portion 10 can be provided with
more than one capillary tube 12 for the purpose of introducing
another fluid into the container portion or to change its
composition, or to effect a reaction or to withdraw a portion of
the fluid sample prior to its injection into the inlet system of
analytical apparatus, or otherwise.
Capillary tubes attached to container portion 10 in accordance with
this invention can be, if preferred, equipped with a pressure
fitting, or threaded fittings of any type suitable for attaching
them to the fluid source, to the inlet of analytical apparatus or
to any other type of apparatus from which the fluid sample is to be
drawn or into which the sample is to be discharged.
The fluid container portion 10 can be made to withstand pressures
of the order of 80 psig and is therefore suitable to serve under a
variety of conditions.
In the modified embodiment of the invention illustrated in FIG. 5
the container portion 50 defined by shallow dome-shaped walls 52
and 54 are adapted to be welded together throughout their entire
peripheries. In this embodiment the capillary tube inlet-outlet
passage is replaced by an aperture 56 of very small diameter which
may be sealed by a drop of solder or by applying an adhesive metal
tape. This modified instrument is applicable in circumstances where
gas samples are to be collected from the atmosphere or from an open
source at atmospheric pressure, for example in air pollution
studies.
The fluid sample may be collected first by collapsing and expanding
container portion 50 to flush out any residual fluid whereupon the
container portion 50 can be finally expanded and aperture 56 sealed
with a drop of solder or by the application of an adhesive metal
tape.
The collected sample may be injected into the inlet of analytical
apparatus against a suitably formed inlet system equipped with a
piercing device whereby fluid communication is established in a
substantially contamination-free manner and delivery of the
contained sample accomplished upon collapsing the container portion
50.
The fluid inlet-outlet passage defined by aperture 56 may if
preferred be provided with a hollow needle or capillary tube such
as illustrated at 12 in FIGS. 1 to 4 which capillary tube can be
suitably anchored therein or at any other location in the walls 52,
54 of container portion 50, as may be desired.
The embodiment of FIG. 5 can be provided with more than one
aperture or more than one capillary tube for the purpose of
introducing a fluid to change the composition of a collected
sample, or to effect a reaction, or to withdraw a portion of the
fluid sample prior to its injection into the inlet system of
analytical apparatus.
While stainless steel is the material from which the preferred
embodiments have been made other suitable sheet material may be
selected for particular applications. Also it should be mentioned
that if the fluid sample to be collected is corrosive the surfaces
in contact with the fluid can be plated or coated with a
substantially non-corrosive, non-contaminating layer as the
particular circumstances may dictate.
It will be understood that the preferred embodiments of the
invention have been described and illustrated herein. Changes or
modifications may be adopted by persons skilled in this field
without departing from the spirit and scope of the invention as
defined in the appended claims.
* * * * *