Note: Descriptions are shown in the official language in which they were submitted.
~93~24825 2 1 3 5 ~ 7 8 PCT/US93/04766
A METHOD AND SYSTEM FOR SAMPLING AND DETERMINING
THE PRESENCE OF CONTAMINANTS IN CONTAINERS
BACKGROUND OF THE INVENTION
The present inventio~ relates to a contalner inspection
syste~ for sampling and determining the presence of certain
substances, such as residues of contaminants within
containers such as glass or plastic bottles. More
specifically, the present invention relates to an improved
sampling and analyzing system and method for determining the
presence of residues of these contaminants in containers such
as beverage bottles rapidly moving along a conveyor past a
test station in a container sorting system.
In many industries, including the beverage industry,
products are packaged in conta~ners which are returned after
use, washed and refilled. Typica.lly refillable containers,
such as beverage bottles, are made of glass which can be
easily cleaned. These containers are washed and then
inspected for the presence of foreign matter.
Glass containers have the disadyantage of being fragile
and, in larger volumes, of being relatively heavy.
A~cord~ngly, it is highly desirable to use plast~c containers
because they are less fragile and lighter than glass
containers of the same volume. ~owever, plastic materials
tend to absorb a variety of organic compounds which may later
be desorbed into the product thereby potentially adversely
W093/24825 ~ 13587~ PCT/US93/04766 ~
affecting the quality of the product packed ln the container.
Examples of such organic compounds are nitrogen contalning
compounds such as ammonia, organic n~trogen compounds, and
hydrocarbons including gasoline and varlous cleaning fluids.
SUMMARY OF THE INVENTION
Accordingly, it is a prlmary ob~ect of the present
invention to provide a method and system for detecting the
presence or absence of a wide range of specific substances -
e.g., contaminants such as nitrogen containing compounds and
hydro~arbons, in containers as the containers move rapidly
along a conveyor on the way to or from a washer assembly or
the like.
It is another object of the present invention to provide
a system and method for sampling and analyzing residues in
containers as they move along a conveyor without stopping the
movement of the containers or impeding the movement in any
way in order that high speed sampl~ng rates of about 200 to
1000 bottles per minute may be achieved.
It is still ano~her object of the present invention to
provide a system and method for sampling and analyzing
residues in containers moving along a conYeyor without
contacting the container being tested with any of the
sampling and analyz~ng mechanisms.
It is yet another obje t of the present inYention to
provide a system and method or samplin~ and analyzing
residues in containers moving alonq a conveyor without the
physical insertion of any probes or the like into the
containers.
It i5 a further ob~ect of the present invention to
provide a system and method for detecting a wide range of
contam~nants in beverage bottles with m{nimum interference
~b 93/2~25 2 1 3 5 8 7 8 PCT/US93/04766
from volatiles of beverage ingredient residues ("product") in
the bottles.
The objects of the present invention are fulfilled by
providing a method of sampling and determining the presence
of certain substances such as volatile residues in containers
comprising the steps of: injecting fluid into ~aid
containers in order to displace at least a portion of the
contents thereof; evacuating a sample of the container
contents so displaced by applying suction thereto; and
analyzing the sample evacuated to determine the presence or
absence of the certain res~dues therein.
In a preferred embodiment the fluid injected into the
containers is compressed air which is injected through a
nozzle to provide an air blast within the interior of the
container. This air blast creates a cloud of the vaporous
contents of the container which emerges from its opening
whereby it may be evacuated by suction from outside of the
container to sample a portion of the container contents.
Injection of fluid and evacuation of sample may be
continuous operations or may be performed in steps. If steps
are utilized, the step of initiating the injection of fluid
- into the container preferably precedes in time the initiation
of the step of evacuating a sample in order to provide time
for the formation o~ the sample cloud. However, the
performance of the steps of injecting and evacuating may
slightly overlap in time. Alternatively, the steps o~
injecting and evacuation may be spaced in time but this is
dependent on the rate of æampling desired. A still further
alternative is to synchronize th~ steps of in~ecting and
evacuating to occur simultaneously for the same duration.
In a preferred embodiment the injection of fluid from
the nozzle and the suction applied by the evacuation means
are continuously on at the test station. In this embodiment
W093/2482~ 2 13 S 8 ~ 8 PCT/US93/04766~
the containers or bo~tle~ are rapidly and continuously moved
through the test station on a rapidly moving conveyor. The
bottles are moved through the test station at a rate of 200
to 1000 bottles per minute. A rate pf 400 bottles per minute
is preferable and is compatible with current beverage bottle
filling speeds. The desired test rate may vary with the size
of the bottles being inspected and filled. The injector
nozzle i5 disposed upstream of the direction of conveyor
movement from the suction tube of the Pvacuator so the
injection of fluid into each container slightly precedes in
time the evacuation of the ~esulting sample cloud.
In another embodiment of the present invention a portion
of the sample evacuated (about 90%) is diverted and the
remaining portion of the sample passes to an analyzer for
determination of the presence or absence of the certain
residues. The purpose of diverting the first pvrtion of the
sample is to limit the amount of sample that passes to the
analyzer to manageable quantities ~n order to achieve high
speed analysis. In addition if the volume of the samp~e is
too large it may foul or clog the detector. However, it is
initially desirable to evacuate essentially the entire sample
cloud to clear the area of the test station from the contents
of that sample cloud to provide clean surroundings for the
successive containers. This eliminates spurious carry over
signals of residue (crosstalk of container contam~nants)
unrelated to the container being tested at a given point in
time.
If desired the diverted portion of the first sample may
be channeled through an optional air filter and recirculated
into the compressed air being injected into subsequent
containers to arrive at the test station. This provides for
an efficient use of the diverted first portion of the sample
and of a pump utilized for diversion and compression, and
` ~93/24825 ~ 1 3 ~ 8 7 8 PCT/US~3/04766
avoids the need to exhaust that first portion of the samplQ
to the atmosphere surrounding the test ~ite.
In a further embodiment a wide range of contaminants are
detectable without interference from product volatile~ by
providing a method of sampling and determining the presence
sf volatiles of certain contaminants in a container which was
previously filled with a beverage, said container including
an opening which is closeable by a cap, comprising the steps
~f:
storing said container with the cap removed for a
sufficient period of time to permit detectable quantities of
volatiles of ingredients in residues of the beverages to
eYaporate and egress from said container;
evacuating a sample of volatiles remaining in the
container after expiration of said sufficient period of time;
mixing the sample with a chemical reactant to cause a
chemical reaction therewith in order to generate
chemiluminescence of the reactants; and
optically analyzing radiation emitted by
chemiluminescence of the sample and reactant to determine the
presence or absence of said volatiles of certain contaminants
without interference from detectable levels of
chemiluminescence of volatiles of ingredients of beverage
residues.
Further scope of applicability of the present invention
will become apparent from the detailed description given
hereinafter. However, it should be understsod that the
detailed description and specific examples, while lndicating
preferred embodiments of the invention, are g~ven by way of
illustration only, since various changes and modifications
within the spirit and scope of the invention will become
apparent to those skilled in the art from this detailed
description.
W093/~25 '~l3~ 87 8 - 6 - PCT/US93/04766'"":
BRIEF DESCRIPTIO~ OF THE DRAWINGS
The present invention will ~ecome~more fully understood
from the detailed description g ~ën hereinbelow and the
accompanying drawings which are gi~ven by way of illustration
only, and thus, are not limitat~ve of the present invention
and wherein:
Fig. 1 is a schematic block diagram of the sampllng and
residue analyzing system of the present invention
illustrating a plurality of containers moving seriatim along
a conveyor system through a test station, reject mechanism
and washer station;
Fig. 2 is a block diagram illustrating a possible
implementation of the system of Fig. 1 in a detector system
in which the contaminant being detected may be a nitrogen
~: 15 containing ¢ompound; and
Fig. 3 is a graph of signal intensity vs. wavelength of
defected radiation emitted by chemiluminescence in the
analyzer of the system of Fig. 2.
, ~
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to Fig. 1 there is illustrated a conveyor 10
: moving in the direction of arrow A having a plurality of
uncapped, open-topped spaced containers C (e.g. plastic
beverage bottles of about 1500 c.c. volume) disposed thereon
for movement seriatim through a test Rtation 12, re~ect
mechanism 28 and conveyor 32 to a washer system. The
contents of containers C would typically include air,
volatiles of residues of contaminants, if any, and volatiles
of any products such as beverages which had been in the
containers. An air injector 14 which is a source of
compressed air is provided with a nozzle 16 spaced from but
:~ aligned with a container C at test station 12. That is
nozzle 16 is disposed outside of the containers and makes no
;"~,, -
,: .
`~93/2~25 2 1 3 5 ~ 7 8 PCT/US93/~766
contact therewith. Nozzle 16 direct~ compressed air into
containers C to displace at least a port~on of the contents
of the container to thereby emit a sample cloud 18 to a
region outside of the container being tested.
S The column of injected air through nozzle 16 into a
container C would be typically of the order of about 10 c.c.
for bottle speeds of about 200 to 1000 bottles per minute.
A rate of 400 bottles per minute is preferable and is
compatible with current beverage bottle filling speeds. The
desired test rate may vary with the s1ze of the bottles being
inspected and filled. Onl~ a~out 10 c.c. of the container
contents would be displaced to regions outside of the bottle
to form sample cloud 18.
Also provided is an evacuator sampler 22 which may
lS comprise a vacuum pump or the like coupled to a sampling tube
or conduit 20. The tube is mounted near, and preferably
downstream (e.g., about 1/16 inch) of the air injector 14 so
as to be in fluid communication with sample cloud 18 ad~acent
to the opening at the top of containers C.
Neither nozzle 16 nor tube 20 contacts the containers C
at test station 12; rather both are spaced at positions
outside of the containers in close proximity to the openings
thereof. This is advantageous in that no physical coupling
is reguired to the containers C, or insertion of probes into
25 the containers, which would impede their raptd movement along
conveyor lQ and thus slow down the sampling rate. High speed
sampling rates of from about 200 to 1000 bot les per minute
are possible with the system and method of the present
invention, The conveyor 10 is preferably driven continuously
to achieve these rates without stopping or slowing the
bottles down at the test station.
A bypas~ line 24 is provided in communication with the
evacuator sampler 22 so that a predetermined portion
W093/2~2~ PCT/US93104766~
2~3S~
- 8 -
(preferably about 90%) of the sample from cloud 18 entering
tube 20 can be diverted through bypass line 24. The
remaining sample portion passes to a residue analyzer 26,
which determines whether specific su~stances are present, and
then is exhausted. One purpose of,~iverting a large portion
of the sample from cloud 18 is to reduce the amount of sample
passing from evacuator sampler 22 to residue an~lyzer 26 in
order to achieve high speed analysis. This is done in order
to provide manageable levels of samples to be tested by the
residue analyzer 26. Another purpose for diverting a portion
of the sample is to be ablQ to substantially remove all of
sample cloud 18 by evacuator 22 from the test station area
and divert the excess through bypass line 24. In a preferred
embodiment the excess portion of the sample passing through
bypass line 24 returned to air injector 14 for introduction
into the subsequent containers moving along conveyor 10
through nozzle 16. However, it would also be possible to
simply vent bypass line 24 to the atmosphere.
A microprocessor controller 34 is provided for
controlling the operation of air injector 14, evacuator
sampler 22, residue analyzer 26, a reject mechanism 28 and an
optional fan 15. Container sensor 17 including ~uxtaposed
radiation source and photodetector is disposed opposite a
reflector (not shown) across conveyor 10. Sensor 17 tells
controller 34 when a conta~ner arrives at the test station
and briefly interrupts the beam of radiation reflected to the
photodetector. Optional fan 15 is provided to generate an
air blast towards sample cloud 18 and preferably in the
direction of movement of containers C to assist ~n the
removal of sample cloud 18 from the vicinity of test station
12 after each container C is sampled. This clears out the
air from the region of the test station so that no lingering
residues from an existing sample cloud 18 c~n contaminate the
~ 93/2~25 2 1 3 5 8 7 8 PCT/US93/04766
test station area when successive conta~ners C reach the test
station for sampling. Thus, sample carryover between
containers is precluded. The duty cycle for operation of fan
is controlled by microprocessor 34 as lndicated
diagrammatically in Fig. 1. Preferably fan 15 ls
continuously operating for the entire time the rest of the
system is operating.
A reject mechanism 28 receives a reject signal from
microprocessor controller 34 when residue analyzer 26
determines that a particular container C is contaminated with
a residue of various undesLrable types. Reject mechanism 28
diverts contaminated rejected bottles to a conveyor 30 and
allows passage of uncontaminated, acceptable bottles to a
washer (not shown) on a conveyor 32.
An alternative option is to place the bottle test
station downstream of the bottle washer in the direction of
conveyor travel, or to place an additional test station and
sample and residue analyzing system after the washer. In
fact it may be preferable to position the test station and
system after the washer when inspecting bottles for some
contaminants. For example, if the contaminant is a
hydrocarbon, such as gasoline which is ~nsoluble in water, ~t
is easier to detect residues of hydrocarbons after the
bottles have been washed. This is because during the washing
process in which the bottles are heated and washed with
water, water soluble chemical volat~les are desorbed from the
bottles by the heating thereof and then dissolved in the
washing water. Certain hydrocarbons, on the other hand, not
being water soluble, may then be sampled by a sampler 22
downstream of the washer, to the exclusion of the dissolved,
water-soluble chemicals. Therefore, the detection of such
hydrocarbons can be performed without potential interference
w093/24825 - 2 135 8~ 8 PCT/US93t~766 ~
-- 10 --
from other water soluble chemicals~if the bottles pass
through a washer before testing.
Referring to Fig. 2 there is illustrated a specific
embodiment of a detector system for use with the sampling and
analyzing system of Fig. 1 wherein like reference numerals
refer to like parts. As illustrated, a nozzle 16 is provided
for generating an air blast which passes into a container
(not shown) being inspected. The air passing through nozzle
16 may be heated or unheated it being advantageous to heat
the air for some applications. Juxtaposed to the nozzle 16
is sample inlet tube 20 inc~uding a filter 40 at the output
thereof for filtering out particles from the sample. Suction
is provided to tube 20 from the suction side of pump 82
connected through the residue analyzer 26.
15A portion of the sample (for example, 90-95% of a total
~-~ sample flow of about 6000 c.c. per minute), as described in
connection with Fig. 1, is diverted through a bypass line 24
by means of connection to the suction side of a pump 46.
Pump 4~ recirculates the air through an accumulator 48, a
normally open blast control valve 50, and back to the air
;~ blast output nozzle 16. A backpressure regulator 54 helps
control pressure of the air blast through nozzle 16 and vents
excess air to exhaust 57. Blast control valve 50 receives
control signals through line 50A from microprocessor
controller 34 to normally maintain the valve open to permit
the flow of air to the nozzle.
Electrical power is provided to pump 46 via line 46A
coupled to the output of circuit breaker 76 which is in turn
coupled to the output of AC filter 74 and AC power supply PS.
30The detector assembly 27 in the embodiment of Fig. 2 is
an analyzer which detects the residue of selected compounds
such as nitrogen containing compounds in the containers being
inspected by means of a method of chemiluminescence. This
:`~
' '~93/24825 ~ 1 3 S 8 7 8 PC~r/US93/04766
type of detector is generally known and includes a chamber
for mixing ozone with nitric oxide, or with other compounds
which react with ozone, in order to allow them to react, a
radiation-transmissive element (with appropriate filter), and
a radiation detector to detect chemiluminescence from the
products of reaction. For example, when NO, produced from
heating nitrogen compounds (such as ammonia) in the presence
of an oxidant (e.g. oxygen in air), chemically reacts with
the ozone, characteristic light emission is given off at
predetermined wavelengths such as wavelengths in the range of
about 0.6 to 2.8 microns. _Selected portions of the emitted
radiation of chemiluminescence, and its intensity, can be
detected by a photomultiplier tube.
Accordingly, in the system of Fig. 2 ambient air is
drawn in throu~h intake 60 and air filter 62 to an ozone
generator 64. Ozone is generated therein, as by electrical
discharge into air, and is output through ozone filter 66 and
flow control valve 68 to the detector assembly 27 where~n it
i5 mixed with samples from containers input through intake
tube 20, filter 40, flow restrictor 42, and converter 44.
The sample from intake tube 20 is passed through a converter
44, such as an electrically-heated nickel tube~ in which the
temperature is raised to approximately 800-C to 900-C before
being input to detector assembly 27. Temperatures in the
range of 400-C to 1400-C may also be acceptable. When
nitrogen-containing compounds such as ammonia are so heated,
NO (nitric oxide) is produced, and the nitr~c oxide is
supplied to the chamber of the detector assembly 27.
Compounds other than NO which may react with O3 and
chemiluminescence may also be produced in converter 44 e.g.,
organic compounds derived from heating of gasoline or
cleaning residue.
W093/2~25 ~ 8~ g PCT/US93/04766
- 12 -
A temperature controller 70 supplied with electrical
power through a transformer 72 i5 used to control the
temperature of converter 44.
The samples in the detector assembly 27 after passage
through its chamber are output!~through an accumulator 85 and
pump 82 to an ozone scrubber S6, and to an exhaust output 57
in order to clear the residue detector for the next sample
from the next container moving along the conveyor 10 of Fig.
1. (As indicated above, an (optinal) fan, not shown in Fig.
2, may be employed to help clear any remaining sample cloud
from near the sample inlet tube 20). Outputs from detector
assembly 27 relating to the results of the tests are output
through a preamp 84 to microprocessor 34 which feeds this
information in a~ appropriate manner to a recorder 83. The
recorder 83 is preferably a conventional strip recorder, or
the like, which displays signal amplitude vs. time of the
sample being analyzed.
The microprocessor 34 may be programmed to recognize, as
a "hit" or the detection of a specific residue, a signal peak
from a photodetector of the detector assembly 27 which is
present in a predetermined time interval (based on the sensed
arrival of a container at the test station) and whose slope
and amplitude reach predetermined magnitudes and thereafter
maintain such levels for a prescribed duration.
The microprocessor controller 34 also has an output to
a ~ottle ejector 2~ to reject contaminated bottles and
separate them from bottles en route to a washer.
A calibration terminal 86 is provided for residue
analyzer 26 for adjusting the high voltage supply 26A
associated with the detector assembly. Also provided is a
recorder attenuator input terminal 88 connected to the
microprocessor controller 34 for adjusting the operation of
` ~ 93/24825 ~ 1 3 5 8 7 8 PC~r/US93/04766
- 13 -
the recorder. Detector assembly 27 receives electrical power
from the high voltage ~upply 26A.
Additional controls include operator pa~el 90 including
a key pad and display section permitting an operator to
S control the operation of the detector assembly 27 in an
appropriate fashion.
DC power is supplied to all appropriate components
throuqh DC power supply 78 coupled to the output of power
supply PS.
An optional alarm enunciator 80A is provided for
signaling an operator of ~he presence of a contaminated-
container. Alarm enunciator 80A is coupled to the output of
microprocessor controller 34 via output control linei80C. A
malfunction alarm 80B is also coupled to microprocessor
controller 34 for receiving fault or malfunction signals such
as from pressure switch 58 or vacuum switch 87 when pressures
are outside of certain predetermined limits.
Other safety devices may be provided such as vacuum
gauge 89, and back pressure control valve 54 for ensuring
proper operation of the system.
Most components of the entire system of Fig. 2 are
preferably enclosed in a rust-proof, 6tainless steel cabinet
~2. The cabinet is cooled by a counter-flow heat exchanger
91 having hermetically separated sections 91A and 91B in
which counter air flow is provided by appropriate fans.
As described hereinbefore the system of Flg. 2 in a
preferred embodiment is utilized to detect the presence of
nitrogen containing compounds in a sample, such as a
refillable beverage bottle. However, it would be desirable
to utilize the system of Fig. 2 to detect as wide a range of
contaminants as possible including potential contaminants
that would chemiluminesce in regions of the radiation
spectrum, which might overlap with chemiluminescence of
W093/24825 PCTtUS93/04766~
2i3S~8
- 14 -
ingredients of a beverage (hereinafter "product") that was
packaged in the beverage bottle.
This is accomplished in accordance with the present
invention by a method partially-illustrated in Fig. 3, and
described hereinafter. i
Referring to Fig. 3, which is a graph of signal
intensity o radiation (in milliYolts) vs. wavelength emitted
by chemiluminescence, it can be observed that radiation
emitted by chemiluminescence of nitrogen containing compounds
lo (the reaction of No + 03) is in the range of about 0.6 to 2.8
microns (near infrared to i~frared radiation). Consequently,
when using the system of Fig. 2 and detector assembly 27
thereof, to look only for nitrogen containing compounds a
cut-off filter 100 is utilized to block all chemiluminescent
radiation of a sample of wavelengths below about 1 micron
from reaching the photomultiplier detector of detector
assembly 27. This is desirable if the detect~on of nitrogen
compounds is of primary interest because chemiluminescent
radiation emitted below 1 micron (visible light to near
infrared) is potentially emitted by "product" res~due in
samples evacuated from refillable beverage bottles.
Therefore, the 1 micron cut-off filter 100 eliminates false
reject signals which might be caused by high levels of
"product" residue in a bottle under test. It is of course
very important to eliminate, or minimize false reject signals~
to minimize, waste of refillable bottles.
However, it is a discovery of the present invention that
if a beverage bottle is stored in an uncapped state, i.e. the
top opening thereof uncovered, for a sufficient tlme prior to
testing with the system of Fig. 2, that volatiles of
"product" residue are sufficiently dissipated from the bottle
that such are not detectable at sufflcient levels to cause
false reject signals. That is, if the 1 micron filter loO is
~-~93/2~25 2 1 3 5 8 7 8 PCT/USg3~04766
- 15 -
removed, and replaced by a quartz cut-off filter having a
cut-off characteristic at .19 micron, "product" volatiles
will not exist in large enough quantities to generate re~ect
signals if the bottles were stored uncapped for a sufficient
period of time. This period of time will vary for various
"products". However, a storage period of about fifteen ~lS)
hours for an uncapped bottle has yielded good results in
tests conducted. These results are tabulated in the
following Table I for samples evacuated from beverage bottles
containing a wide range of contaminants, and "product"
residues.
wog3/24X25'213S878 PCI`/US93/~4766
-- 16 --
q~Al~Ll~ S
SWLE Filt~r 10Z Flltor 106 Fllter 100
~Oi~19 ~cron)~0, ~lcron) t1 icron)
~cetaldehye ``60 3
Acetone ~ 1100 50
Acetone, 15Hr, Uncapped 40 0
Bra21l Gac OS
Brl~ll Ga~ ~ 1
Cyclohexanone 2500
Cyclohexsnone, 15Hr, Uncopped OS O
Dlesel 5
Douny, 15Hr, Uncnpped 3 0
Exxon 100 70 30
Exxon 150 25 10
Exx 200 6 2
fresh Do~ny 2
Gas #1 325
Gas #3 '
Hexune 50 20
Nexare, 15Hr, Uncapped 80 O
Isopropano( 40
IsopropDnol, 15Hr, UncDppeci 200 2
l~eroslne 6
~ethanol 60 0
ilethylene Chlorlde 12 3
~ethylerle Chloride, 15Hr, Uncappe< 2û 0
l~lne 80
Cola, Classlc, 15Hr, Capped S 0 O
Cola, Classlc, 15Hr, Urcapped 0 0
Cola, Classic Fresh 2 3 0
3 0 Colo, Diet, 15Hr, Copped 2 0 0
Cola, Diet, 15Hr, Unropped 0 0
- Colll, Diet, Fresh 3 2 0
Oron~e, tSHr, Capped 15 3 3
Orange, 15Hr, Uncappe~ 0
3 5 Orange, Dlet, 15Hr, Copped 2S 3
Or3rge, Diet, 15Hr, Uncapped 0 0
Orar~e, Dlet, ~resh 25 25
Fanta fresh 20 25 0
L~Lia~e, 15Hr, Capped 2 0 0
4 0 Len~n/L~e, 15Hr, Uncapped 0 0
Lemor~/Lin~?, Diet, 15Hr, Cnpped 20 0 0
Lemon~Llme, D~et, 15Hr, Uncapped 0 0
Len~n/Llme, Dlet Fresh 2 3 0
L~n/Lime, Fresh 3 2 Q
~ l~urbers in coluns 2 to ' ln ~illivolts
OS ~ Off Scale Reading
f ;~93/2482~ 2 1 3 5 8 7 ~ PCT/US93/04766
- 17 -
Column 1 of Table I in the upper portion lists "samples"
including potential contaminants in beverage bottles which
are detectable by the method and ~ystem of the present
invention. These contaminants are detectable in a~dition to
nitrogen containing compounds. The designation "Uncapped"
means that the residue-containing bottle was stored for the
indicated time with its top opening uncovered; undesignated
entries indicate that the contaminant was present, and top
opening uncovered, for only a brief time prior to testing.
The "samples" in the lower part of column 1 include
examples of beverage produc~t tested ,and an indication of
whether the bottles were capped, uncapped, and if uncapped
the storage period of the residue-containing bottle with its
top opening uncovered for example 15 hrs. The designation
"Capped) means that the bottle was tested with a residue of
the beverage procut present, and the top opening uncovered
for only a brief period prior to testing. The designation
"Fresh" means that the bottle was tested soon after opening
it, and contained fresh product in liquid form, i.e. a
substantially full bottle of beverage, rather than old
fermented product.
Column 2 of Table I shows the intensity in millivolts of
signals measured by a photomultiplier tube 1~4 in detector
assembly 27 with a 0.19 micron quartz cut-off filter 102 at
the input window of the photomultiplier tube 104. It can be
seen that signals of signi~icant detectable levels exist for
these contaminants for capped or uncapped beverage bottles.
The data in column 2 also indicates that for "uncapped"
beverage bottles stored for 15 hrs. that "product" volatiles
are undetectable (0 millivolts) by photomultiplier tube 104.
Column 4 of Table I shows test results of a system
including the 1 mi~ron filter 100, and the levels in
millivolts of detectable signals for the various contaminants
W O 93/24825 ~3S~ ~ P~r/US93/04766 ~
- 18 -
or products of column 1. It can be s~én that essentially all
useful signal data relat~ng to contaminants in Table I is
lost with the 1 micron filter lOQ~~in place.
Column 3 of Table I shows r~sults with a 0.4 micron cut-
off filter 106 installed at the~:`input of photomultiplier tube
104 in place of either filters 100 or 102. It can be seen
that some useful contaminant data is detectab~e when using a
0.4 micron cut-off filter 102.
Therefore, the discovery of the present invention that
storage of beverage bottles in an uncapped state removes the
possibility of developing fa~se reject signals from "product'-
volatiles, is a most significant and beneficial discovery.
That is, the process of the present invention which embodies
the concept of storing uncapped beverage bottles for a
sufficient time to permit "product" volatiles to dissipate,
enables the detection of a wide range of other contaminants
such as those listed in Table I in addition to contaminants
including nitrogen containing compounds.
The invention being thus described, it will be obvious
that the same may be varled in many ways. For example, other
forms of high speed analyzers, such as electron capture
detectors or photoionization detectors, may be suitable in
place of the chemiluminescence analyzer described with
reference to Fig. 2.
Also the sample sucked into the tube 20 may be separated
into two or more streams and input to a plurality of
analyzers 26. Consequently, each analyzer 26 could be used
to detect different types of contaminants.
In addition the materials to be inspected are not
limited to substances in containers. For example, the method
and system of the present invention could be used to detect
volatiles adsorbed in shredded strips or flakes of resins, or
plastic stock to be recycled for manufacturing new plastic
~ 2I3S873
~93/2~25 - PCT/US93/04766
-- 19 --
beverage bottles. This ~hredded or flaked plastic stock
could be placed directly on a conveyor belt 10 and passed
through test station 12 of Fig. l; or the plastic stock could
be placed in baskets, buckets or other types of containers
disposed thereon and inspected in batches.
Still further the bottles being tested may be new
bottles that have never been filled with a beverage. Thus,
new bottles could be tested for excessive acid aldehyde
content, which may be a byproduct of the manufacturing
process.
Such variations are not to be regarded as a departure
from the spirit and scope of the invention, and all such
modifications as would be obvious to one skilled in the art
are intended to be included within the scope of the following
claims.
