U.S. patent application number 15/039100 was filed with the patent office on 2017-01-26 for rugged target-analyte permeation testing instrument employing a consolidating block manifold.
This patent application is currently assigned to MOCON, INC.. The applicant listed for this patent is MOCON, INC.. Invention is credited to Slava A. Berezovskiy, Daniel W. Mayer.
Application Number | 20170023463 15/039100 |
Document ID | / |
Family ID | 53879127 |
Filed Date | 2017-01-26 |
United States Patent
Application |
20170023463 |
Kind Code |
A1 |
Mayer; Daniel W. ; et
al. |
January 26, 2017 |
RUGGED TARGET-ANALYTE PERMEATION TESTING INSTRUMENT EMPLOYING A
CONSOLIDATING BLOCK MANIFOLD
Abstract
A target-analyte permeation testing instrument (10)
characterized by a block manifold (100) retaining the testing cells
(70n) of the instrument (10).
Inventors: |
Mayer; Daniel W.; (Wyoming,
MN) ; Berezovskiy; Slava A.; (Apple Valley,
MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
MOCON, INC. |
Minneapolis |
MN |
US |
|
|
Assignee: |
MOCON, INC.
Minneapolis
MN
|
Family ID: |
53879127 |
Appl. No.: |
15/039100 |
Filed: |
February 24, 2015 |
PCT Filed: |
February 24, 2015 |
PCT NO: |
PCT/US15/17193 |
371 Date: |
May 25, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61943772 |
Feb 24, 2014 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 15/0826 20130101;
G01N 2015/086 20130101; G01N 35/00693 20130101; G01N 15/0806
20130101; G01N 35/00712 20130101; G01N 33/004 20130101; G01N
35/1097 20130101 |
International
Class: |
G01N 15/08 20060101
G01N015/08 |
Claims
1. A target-analyte permeation testing instrument for measuring
target-analyte permeation rate of a test film in test cell, the
instrument having a target-analyte sensor and a plurality of test
cells each defining a testing chamber with each test cell operable
for retaining a test film to sealingly divide the testing chamber
into a driving chamber and a sensing chamber, the target-analyte
permeation testing instrument characterized by a block manifold (-)
fixed to the plurality of cells, and (-) having a plurality of
channels in fluid communication with the testing chamber of each
cell, a pressurized source of driving gas, a pressurized source of
inert gas, and the target-analyte sensor, wherein the plurality of
channels are configured and arranged to (i) selectively carry
driving gas from the pressurized source of driving gas to the
driving chamber of each cell, (ii) carry driving gas from the
driving chamber of each cell to a driving gas exit port in the
manifold, (iii) selectively carry inert gas from the pressurized
source of inert gas to the sensing chamber of each cell, and (iv)
selectively carry inert gas from the sensing chamber of each cell
to the target-analyte sensor.
2. The target-analyte permeation testing instrument of claim 1
wherein the block manifold further includes a refillable first
water reservoir in selective fluid communication with the source of
driving gas and in fluid communication with the driving chamber of
each cell, and a second refillable water reservoir in selective
fluid communication with the source of inert gas and in fluid
communication with the sensing chamber of each cell.
3. The target-analyte permeation testing instrument of claim 1
wherein the block manifold is constructed from a single unitary
metal block.
4. The target-analyte permeation testing instrument of claim 1
wherein the channels in fluid communication with the pressurized
source of driving gas and the driving chamber of each cell are in
fluid communication with at least one block mounted valve operable
for effecting selective delivery of driving gas to the driving
chambers of the cells.
5. The target-analyte permeation testing instrument of claim 1
wherein the channels in fluid communication with the pressurized
source of inert gas and the sensing chamber of each cell are in
fluid communication with at least one block mounted valve operable
for effecting selective delivery of inert gas to the sensing
chambers of the cells.
6. The target-analyte permeation testing instrument of claim 1
wherein the channels in fluid communication with the sensing
chamber of each cell and the target-analyte sensor are in fluid
communication with at least one block mounted valve operable for
effecting selective delivery of inert gas from the sensing chambers
of the cells to the target-analyte sensor.
Description
BACKGROUND
[0001] Permeation instruments are used to measure the transmission
rate of a target analyte, such as oxygen, carbon dioxide or water
vapor, through various samples, such as membranes, films,
envelopes, bottles, packages, containers, etc. (hereinafter
collectively referenced as "test films" for convenience). Typical
test films are polymeric packaging films such as those constructed
from low density polyethylene (LDPE), high density polyethylene
(HDPE), oriented polypropylene (OPP), polyethylene terepthalate
(PET), polyvinylidene chrloride (PVTDC), etc. Typically, the film
to be tested is positioned within a test chamber to sealing
separate the chamber into first and second chambers. The first
chamber (commonly referenced as the driving or analyte chamber) is
filled with a gas containing a known concentration of the target
analyte (commonly referenced as a driving gas). The second chamber
(commonly referenced as the sensing chamber) is flushed with an
inert gas (commonly referenced as a carrier gas) to remove any
target analyte from the cell. A sensor for the target analyte is
placed in fluid communication with the sensing chamber for
detecting the presence of target analyte that has migrated into the
sensing chamber from the driving chamber through the test film.
Exemplary permeation instruments for measuring the transmission
rate of oxygen (O.sub.2), carbon dioxide (CO.sub.2) and water vapor
(H.sub.2O) through test films are commercially available from
Mocon, Inc. of Minneapolis, Minn. under the designations OXTRAN,
PERMATRAN-C and PERMATRAN-W, respectively.
[0002] Permeation instruments are being used more often to measure
ever decreasing concentrations of target-analyte, into the ppm or
even ppb range, and are therefore extremely sensitive to even
minute atmospheric contamination of the fluids used in the
instrument. Permeation instruments employ an extensive network of
fluid interconnections with numerous valves to achieve the desired
choreographed flow of driving and carrier gas through the
instrument, especially when the instrument employs a plurality of
testing cells in fluid communication with a single common
target-analyte sensor. Each fitting in the fluid transfer system of
the instrument is a potential source of contamination as
atmospheric oxygen, carbon dioxide and water vapor leak around or
permeate through the seals on the fittings, especially as the seals
on the fittings loosen over time.
[0003] Accordingly, a substantial need exists for a permeation
instrument capable near elimination of atmospheric-induced
contamination of the driving and carrier gases flowing through the
instrument throughout the lifespan of the instrument.
SUMMARY OF THE INVENTION
[0004] The invention is a target-analyte permeation testing
instrument characterized by a block manifold. The instrument has a
target-analyte sensor and a plurality of test cells for measuring
target-analyte permeation rate of a test film. Each test cell
defines a testing chamber and is operable for retaining a test film
to sealingly divide the testing chamber into a driving chamber and
a sensing chamber. The block manifold is fixed to the plurality of
cells and has a plurality of channels in fluid communication with
the testing chamber of each cell, a pressurized source of driving
gas, a pressurized source of inert gas, and a target-analyte
sensor. The plurality of channels are configured and arranged to
selectively carry driving gas from the pressurized source of
driving gas to the driving chamber of each cell, carry driving gas
from the driving chamber of each cell to a driving gas exit port in
the manifold, selectively carry inert gas from the pressurized
source of inert gas to the sensing chamber of each cell, and
selectively carry inert gas from the sensing chamber of each cell
to the target-analyte sensor.
[0005] The block manifold can include a refillable first water
reservoir in selective fluid communication with the source of
driving gas and in fluid communication with the driving chamber of
each cell, and a second refillable water reservoir in selective
fluid communication with the source of inert gas and in fluid
communication with the sensing chamber of each cell.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a schematic plumbing diagram of one embodiment of
the invention.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
TABLE-US-00001 [0007] Nomenclature Table 10 Target-Analyte
Permeation Testing Instrument 20A Test Gas RH Control Valve 20B
Carrier Gas RH Control Valve 30B.sub.wet Catalyst Chamber in Wet
Carrier Gas Line 30B.sub.dry Catalyst Chamber in Dry Carrier Gas
Line 40A.sub.wet Particle Filter in Wet Test Gas Line 40A.sub.dry
Particle Filter in Dry Test Gas Line 40B.sub.wet Particle Filter in
Wet Carrier Gas Line 40B.sub.dry Particle Filter in Dry Carrier Gas
Line 50A Water Reservoir for Test Gas 50B Water Reservoir for
Carrier Gas 60.sub.n Capillary Restrictors 60.sub.1A Capillary
Restrictor for Test Gas Channel to First Test Cell 60.sub.2A
Capillary Restrictor for Test Gas Channel to Second Test Cell
60.sub.1B Capillary Restrictor for Carrier Gas Channel to First
Test Cell 60.sub.2B Capillary Restrictor for Carrier Gas Channel to
Second Test Cell 60.sub.9B Capillary Restrictor for Carrier Gas
Channel to Rezero Valve 70.sub.n Testing Cells 70.sub.nA Driving
Chamber of Test Cell n 70.sub.nB Sensing Chamber of Test Cell n
70.sub.nAx Exhaust from Driving Chamber of Test Cell n 70.sub.1
First Testing Cells 70.sub.1A Driving Chamber of First Test Cell
70.sub.1Ax Exhaust from Driving Chamber of First Test Cell
70.sub.1B Sensing Chamber of First Test Cell 70.sub.2 Second
Testing Cells 70.sub.2A Driving Chamber of Second Test Cell
70.sub.2Ax Exhaust from Driving Chamber of Second Test Cell
70.sub.2B Sensing Chamber of Second Test Cell 80.sub.nB Carrier Gas
Sensing Chamber Exit Valve for Testing Cell n 80.sub.1B First Test
Cell Carrier Gas Exit Valve 80.sub.1Bx Exhaust from Sensing Chamber
of First Test Cell 80.sub.2B Second Test Cell Carrier Gas Exit
Valve 80.sub.2Bx Exhaust from Sensing Chamber of Second Test Cell
88B Cell Selector Channel Conditioning Valve 88Bx Exhaust from Cell
Selector Channel Conditioning Valve 89B Rezero Valve 89Bx Exhaust
from Rezero Valve 100 Block Manifold 101A.sub.wet Test Gas Water
Reservoir Inlet Port 101A.sub.dry Test Gas Water Reservoir Bypass
Inlet Port 101B.sub.wet Carrier Gas Water Reservoir Inlet Port
101B.sub.dry Carrier Gas Water Reservoir Bypass Inlet Port 102
Carrier Gas Outlet Port to Sensor 200 Target-Analyte Sensor 210
Sensor Exhaust Valve 300.sub.n Gas Flow Line n 300.sub.0A.sub.wet
Test Gas Water Reservoir Inlet Line 300.sub.0A.sub.dry Test Gas
Water Reservoir Bypass Inlet Line 300.sub.0B.sub.wet Carrier Gas
Water Reservoir Inlet Line 300.sub.0B.sub.dry Carrier Gas Water
Reservoir Bypass Inlet Line 300.sub.1A.sub.in Test Gas First
Testing Cell Inlet Line 300.sub.1B.sub.in Carrier Gas First Testing
Cell Inlet Line 300.sub.2A.sub.in Test Gas Second Testing Cell
Inlet Line 300.sub.2B.sub.in Carrier Gas Second Testing Cell Inlet
Line 300.sub.nB.sub.out Carrier Gas Outlet Line for Testing Cell n
300.sub.1B.sub.out Carrier Gas First Testing Cell Outlet Line
300.sub.2B.sub.out Carrier Gas Second Testing Cell Outlet Line
300.sub.5 Shared Carrier Gas Testing Cell Outlet Line 300.sub.9B
Carrier Gas Rezero Line A Driving or Test Gas Source B Inert or
Carrier Gas Source F Test Film
DESCRIPTION
[0008] Referring generally to FIG. 1, the invention is a
target-analyte permeation testing instrument 10 characterized by a
block manifold 100, preferably a solid block cast metal manifold
100 into which the appropriate channels and compartments are
formed. The instrument 10 has a target-analyte sensor 200 and a
plurality of test cells 70.sub.n for measuring target-analyte
permeation rate of test films F.sub.n. Each test cell 70.sub.n
defines a testing chamber and is operable for retaining a test film
F to sealingly divide the testing chamber into a driving chamber
70.sub.nA and a sensing chamber 70.sub.nB. The cells 70.sub.n are
secured to the block manifold 100. The block manifold 100 has a
plurality of channels 300.sub.n in fluid communication with the
testing chamber of each cell 70.sub.n, a pressurized source of
driving gas A, a pressurized source of inert gas B, and a
target-analyte sensor 200. The plurality of channels 300.sub.n are
configured and arranged to selectively carry driving gas from the
pressurized source of driving gas A to the driving chamber
70.sub.nA of each cell 70.sub.n, carry driving gas from the driving
chamber 70.sub.nA of each cell 70.sub.n to a driving gas exit port
70.sub.nAx in the manifold 100, selectively carry inert gas from
the pressurized source of inert gas B to the sensing chamber
70.sub.nB of each cell 70.sub.n, and selectively carry inert gas
from the sensing chamber 70.sub.nB of each cell 70.sub.n to a the
target-analyte sensor 200.
[0009] The block manifold 100 can include a refillable first water
reservoir 50A in selective fluid communication with the source of
driving gas A and in fluid communication with the driving chamber
70.sub.nA of each cell 70.sub.n, and a second refillable water
reservoir 50B in selective fluid communication with the source of
inert gas B and in fluid communication with the sensing chamber
70.sub.nB of each cell 70.sub.n.
[0010] An exemplary two-cell embodiment of the invention 10 is
depicted in FIG. 1. The permeation testing instrument 10 preferably
includes humidification systems for each of the test gas and
carrier gas, such as described in U.S. Pat. Nos. 7,578,208 and
7,908,936, the disclosures of which are hereby incorporated by
reference.
[0011] A source of dry test gas A fluidly communicates with a first
humidification system that includes a wet line 300.sub.0A.sub.wet
in fluid communication with a water reservoir 50A and a dry line
300.sub.0A.sub.dry that bypasses the water reservoir 50A. A test
gas RH control valve 20A controls flow of test gas through the wet
line 300.sub.0A.sub.wet and dry line 300.sub.0A.sub.dry according
to a duty cycle for achieving the desired humidification level of
the test gas.
[0012] The test gas wet line 300.sub.0A.sub.wet enters the block
manifold 100 at inlet port 101A.sub.wet. The test gas dry line
300.sub.0A.sub.dry enters the block manifold 100 at inlet port
101A.sub.dry.
[0013] Upon exiting the water reservoir 50A, humidified test gas in
the wet line 300.sub.0A.sub.wet is combined with dry test gas in
the dry line 300.sub.0A.sub.dry and the combined test gas directed
by test gas inlet lines 300.sub.1A and 300.sub.2A to the driving
chambers 70.sub.1A and 70.sub.2A in the first testing cell 70.sub.1
and second testing cell 70.sub.2 respectively. Test gas flows
through and exits each of the driving chambers 70.sub.1A and
70.sub.2A through an outlet port (unnumbered) and is vented from
the block manifold at vent ports 70.sub.1Ax and 70.sub.2Ax
respectively.
[0014] Particle filters 40A.sub.wet and 40A.sub.dry are preferably
provided in the test gas wet line 300.sub.0A.sub.wet and test gas
dry line 300.sub.0A.sub.dry respectively, for removing any
entrained particulate matter from the test gas before it enters the
block manifold 100.
[0015] In a similar fashion, a source of dry carrier gas B fluidly
communicates with a second humidification system that includes a
wet line 300.sub.0B.sub.wet in fluid communication with a water
reservoir 50B and a dry line 300.sub.0B.sub.dry that bypasses the
water reservoir 50B. A carrier gas RH control valve 20B controls
flow of carrier gas through the wet line 300.sub.0B.sub.wet and dry
line 300.sub.0B.sub.dry according to a duty cycle for achieving the
desired humidification level of the carrier gas.
[0016] The carrier gas wet line 300.sub.0B.sub.wet enters the block
manifold 100 at inlet port 101B.sub.wet. The carrier gas dry line
300.sub.0B.sub.dry enters the block manifold 100 at inlet port
101B.sub.dry.
[0017] Upon exiting the water reservoir 50B, humidified carrier gas
in the wet line 300.sub.0B.sub.wet is combined with dry carrier gas
in the dry line 300.sub.0B.sub.dry and the combined carrier gas
directed by carrier gas inlet lines 300.sub.1B and 300.sub.2B to
the sensing chambers 70.sub.1B and 70.sub.2B in the first testing
cell 70.sub.1 and second testing cell 70.sub.2 respectively.
Carrier gas flows through and exits each of the sensing chambers
70.sub.1B and 70.sub.2B through an outlet port (unnumbered) and is
directed by dedicated outlet channels 300.sub.1B.sub.out and
300.sub.2B.sub.out respectively, to a common channel 300.sub.5 in
fluid communication with a target-analyte sensor 200 located
external to the block manifold 100.
[0018] Common channel 300.sub.5 exits the block manifold 100 at
outlet port 102.
[0019] Particle filters 40B.sub.wet and 40B.sub.dry are preferably
provided in the carrier gas wet line 300.sub.0B.sub.wet and carrier
gas dry line 300.sub.0B.sub.dry respectively, for removing any
entrained particulate matter from the carrier gas before it enters
the block manifold 100.
[0020] Target-analyte catalytic converters 30B.sub.wet and
30B.sub.dry are preferably provided in the carrier gas wet line
300.sub.0B.sub.wet and carrier gas dry line 300.sub.0B.sub.dry
respectively, for converting any target-analyte in the carrier gas
(e.g., O.sub.2) to a molecular species (e.g., H.sub.2O when the
target analyte is O.sub.2) that will not be detected by the
target-analyte sensor 200.
[0021] Capillary restrictors 60.sub.1A, 60.sub.2A, 60.sub.1B and
60.sub.2B are preferably provided in the test gas inlet lines
300.sub.1A and 300.sub.2A, and carrier gas inlet lines 300.sub.1B
and 300.sub.2B respectively, for facilitating a consistent and
equal flow of gas into the driving chambers 70.sub.1A and 70.sub.2A
of the testing cells 70.sub.1 and 70.sub.2, and the sensing
chambers 70.sub.1B and 70.sub.2B of the testing cells 70.sub.1 and
70.sub.2 respectively. The capillary restrictors 60.sub.n are
preferably side mounted onto the block manifold 100.
[0022] Valves 80.sub.1B and 80.sub.2B are provided in the dedicated
outlet channels 300.sub.1B.sub.out and 300.sub.2B.sub.out
respectively, for selectively and mutually exclusively allowing
passage of carrier gas, containing any target-analyte that has
permeated through the test film F, from each of the sensing
chambers 70.sub.1B and 70.sub.2B into sensing engagement with the
sensor 200. When closed, the valves 80.sub.1B and 80.sub.2B vent
carrier gas, containing any target-analyte that has permeated
through the test film F, to atmosphere through vent ports
80.sub.1Bx and 80.sub.2Bx in the manifold 100. The valves 80.sub.nB
are preferably side mounted onto the block manifold 100.
[0023] The instrument 10 depicted in FIG. 1 includes an optional
channel conditioning feature. Permeation testing instruments 10
employ a very low mass flow through rate through the gas flow lines
300n of the instrument 10 to limit the creation of any pressure
differentials in the instrument 10 that could impact humidification
of the test and/or carrier gases or create a pressure-induced
driving force across a test film F. This low mass flow rate through
the instrument 10 imposes a significant time delay between
measurements from different testing cells 70.sub.n as both the
"stale" carrier gas contained in the length of the testing cell
outlet line 300.sub.nB.sub.out for the upcoming testing cell
70.sub.n to be measured and the "inapplicable" carrier gas
contained in the length of the shared outlet line 300.sub.5 from
the previously measured testing cell 70.sub.n is flushed from the
lines and replaced with fresh carrier gas, containing any
target-analyte that has permeated through the test film F, from the
upcoming testing cell 70.sub.n. A channel conditioning feature
employs a cell selector channel conditioning valve 88B in the
shared outlet line 300.sub.5 for allowing, in coordination with
opening and closing of valves 80.sub.nB for the upcoming and
previous testing cells 70.sub.n, for advanced venting of "stale"
carrier gas contained in the length of the outlet line
300.sub.nB.sub.out for the upcoming testing cell 70.sub.n. The cell
selector channel conditioning valve 88B is operable as between a
flow-through state, in which carrier gas is directed to the sensor
200, and a vent state, in which carrier gas is vented to atmosphere
through a vent port 88Bx in the block manifold 100. The cell
selector channel conditioning valve 88B is preferably side mounted
to the block manifold 100.
[0024] The instrument 10 depicted in FIG. 1 includes an optional
rezero feature. Rezero is a method of measuring residual
target-analyte contained in the carrier gas during performance of
testing that includes the steps of bypassing the test cell(s)
70.sub.n and directly measuring the carrier gas target-analyte
level, which is then subtracted from the measured transmission rate
of the target-analyte level for each sample.
[0025] The rezero feature includes a rezero line 300.sub.9B
upstream from the testing cells 70.sub.n for bypassing the testing
cells 70.sub.n and carrying carrier gas directly to the sensor 200.
A rezero valve 89B is provided in the rezero line 300.sub.9B for
selectively directing carrier gas to the sensor 200 or venting
carrier gas from the block manifold 100 at vent port 89Bx. The
rezero valve 89B is preferably side mounted to the block manifold
100.
[0026] A capillary restrictor 60.sub.9B is preferably provided in
the carrier gas rezero line 300.sub.9B for facilitating a
consistent and equal flow of carrier gas into the sensing chambers
70.sub.1B and 70.sub.2B of the testing cells 70.sub.1 and 70.sub.2
respectively. The capillary restrictor 60.sub.9B is, as with the
other capillary restrictors, preferably side mounted onto the block
manifold 100.
[0027] The sensor 200 is selected to measure the appropriate
target-analyte (e.g., oxygen (O.sub.2), carbon dioxide (CO.sub.2)
or water vapor (H.sub.2O)). Selection of a suitable sensor 200 is
well within the knowledge and expertise of a person having routine
skill in the art. The sensor 200 is preferably a coulox sensor and
is equipped with an exhaust valve 210 for preventing atmospheric
contamination of the sensor when there is no flow of carrier gas to
the sensor 200.
* * * * *