Patent US3632210A successfully refreshed from Google Patents.
US3632210A
Expired / Lapsed
US
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Variable rate continuous flow condensation nuclei meter having adjustable expansion period and improved gain
Assignee: Environment One Corp
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Filing: 1969-06-19
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Granted: 1972-01-04
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Expires: 1989-06-19
Abstract
Abstract A variable rate continuous flow condensation nuclei meter is described which includes an expansion chamber having inlet and outlet passageways for introducing into and withdrawing from the expansion chamber specimens of a sample gaseous atmosphere to be monitored for condensation nuclei. Inlet and outlet cutoff valves are disposed in the inlet and outlet passageway for allowing a specimen of a sample gaseous atmosphere being monitored to be drawn from an intake probe or other sample atmosphere intake arrangement through the inlet passageway and expansion chamber, out the outlet passageway and to a source of low pressure provided by a suitable evacuating apparatus. With the valves open, differential flow of a sample gaseous atmosphere takes place from the intake probe through the expansion chamber into the evacuated space. During each operating cycle the inlet and outlet valves are closed simultaneously for at least a short time duration sample interval to trap a specimen of the atmosphere being tested in the expansion chamber during the sample interval. At this point, the interior of the expansion chamber is suddenly decreased in pressure so as to form small liquid droplets around the condensation nuclei contained in the gaseous atmosphere as centers. A radiant energy irradiating and detecting device is positioned to view the interior of the expansion chamber and is operative during the sample interval to derive an output electric signal representative of the intensity of the radiant energy attenuated or scattered by the small liquid droplets thus formed on the condensation nuclei as centers. The output electrical signal thus derived comprises a measure of the number of condensation nuclei contained in the specimen of the gaseous atmosphere being tested during each sample interval. Following measurement the interior of the expansion chamber is recompressed to a pressure corresponding to its preexpansion value. A bypass flow path is connected in parallel with the expansion chamber and is designed such that with the inlet and outlet valves open, a portion of the flow of the sample gaseous atmosphere takes place through the expansion chamber, and with the inlet and outlet valves closed substantially all of the flow takes place through the bypass flow path and a continuous flow rate is maintained over a complete operating cycle and from one operating cycle to the next. Additional means are provided for variably controlling the flow rate of the sample gaseous atmosphere being monitored through the condensation nuclei meter by a suitable control valve or replaceable restriction located in a passageway common to the parallel connected expansion chamber and bypass path. The length of time or period of the expansion cycle apparatus employed with the condensation nuclei meter is separately adjustable independently of flow rate to provide a linear measurement of particle count over a wide range of particle concentrations.
Inventors
- 👤 Theodore A Rich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:36
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/06; G01N15/065
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
280 words
A variable rate continuous flow condensation nuclei meter comprising housing means defining an expansion chamber, means defining inlet and outlet passageways to said expansion chamber for introducing into and withdrawing from said expansion chamber specimens of an atmosphere to be monitored for condensation nuclei during each measurement cycle, valving means disposed in said inlet and outlet passageways for selectively opening and closing the passageways, means for connecting the outlet passageway to a source of low pressure gas to provide for differential flow of a sample gaseous atmosphere from a sample intake means for the meter through the expansion chamber with the valving means in an open condition, means for periodically closing said inlet and outlet valving means synchronously for at least a short time duration sampLe interval for trapping a specimen of a gaseous atmosphere to be monitored in the expansion chamber during the sample interval, means for suddenly decreasing the pressure in the expansion chamber during the sample interval with the valving means in a closed condition and for returning the pressure in the expansion chamber to substantially its predecompression value prior to opening the valving means and initiating a new measurement cycle, and radiant energy irradiating and detecting means viewing the interior of the expansion chamber and operative during the sample interval to derive an output electric signal representative of the intensity of the radiant energy modified by small liquid droplets formed on the condensation nuclei as centers upon the occurrence of the sudden decrease in pressure in the expansion chamber, the magnitude of the output electric signal thus derived comprising a measure of the number of condensation nuclei contained in the specimen of gaseous atmosphere being monitored.
Claim 2
Dependent Claim
280 words
A variable rate continuous flow condensation nuclei meter comprising housing means defining an expansion chamber, means defining inlet and outlet passageways to said expansion chamber for introducing into and withdrawing from said expansion chamber specimens of an atmosphere to be monitored for condensation nuclei during each measurement cycle, valving means disposed in said inlet and outlet passageways for selectively opening and closing the passageways, means for connecting the outlet passageway to a source of low pressure gas to provide for differential flow of a sample gaseous atmosphere from a sample intake means for the meter through the expansion chamber with the valving means in an open condition, means for periodically closing said inlet and outlet valving means synchronously for at least a short time duration sampLe interval for trapping a specimen of a gaseous atmosphere to be monitored in the expansion chamber during the sample interval, means for suddenly decreasing the pressure in the expansion chamber during the sample interval with the valving means in a closed condition and for returning the pressure in the expansion chamber to substantially its predecompression value prior to opening the valving means and initiating a new measurement cycle, and radiant energy irradiating and detecting means viewing the interior of the expansion chamber and operative during the sample interval to derive an output electric signal representative of the intensity of the radiant energy modified by small liquid droplets formed on the condensation nuclei as centers upon the occurrence of the sudden decrease in pressure in the expansion chamber, the magnitude of the output electric signal thus derived comprising a measure of the number of condensation nuclei contained in the specimen of gaseous atmosphere being monitored.
Claim 3
Dependent Claim
63 words
A variable rate continuous flow condensation nuclei meter according to claim 1 further including a bypass flow path connected in parallel with the expansion chamber intermediate the input to the inlet passageway valving means and the outlet of the outlet passageway valving means for providing a continuous flow path for a sample gaseous atmosphere around the expansion chamber during the periodic sample intervals.
Claim 4
Dependent Claim
32 words
A variable rate continuous flow condensation nuclei meter according to claim 2 further including means for variably controlling the flow rate of the gaseous atmosphere being monitored though the condensation nuclei meter.
Claim 5
Dependent Claim
97 words
A variable rate continuous flow condensation nuclei meter according to claim 3 further including means in the bypass flow path for restricting the flow rate through the bypass flow path relative to the expansion chamber during open intervals of the inlet and outlet passageway valving means whereby during such intervals a portion of the gaseous atmosphere being monitored flows through the expansion chamber and during the sample interval substantially all flow takes place through the bypass path and a continuous flow rate is maintained over a complete operating cycle and from one operating cycle to the next.
Claim 6
Dependent Claim
75 words
A variable rate continuous flow condensation nuclei meter according to claim 3 wherein said means for variably controlling the flow rate of the gaseous sample through the condensation nuclei meter comprises adjustable flow regulating means interposed in the flow passageway intermediate the sample intake means for the meter and the source of low pressure gas and at a point common to the parallel flow paths formed by the expansion chamber and the bypass flow path.
Claim 7
Dependent Claim
40 words
A variable rate continuous flow condensation nuclei meter according to claim 1 further including sample interval periodicity adjusting means for variably controlling the time duration of the sample interval period during which the pressure within the expansion chamber is decreased.
Claim 8
Dependent Claim
56 words
A variable rate continuous flow condensation nuclei meter according to claim 6 wherein the sample interval periodicity adjusting means comprises replaceable capillary means for variably controlling the size of a venting passageway controlling the time duration of the expansion period provided by the means for suddenly decreasing the pressure within the interior of the expansion chamber.
Claim 9
Dependent Claim
40 words
A variable rate continuous flow condensation nuclei meter according to claim 5 further including sample interval periodicity adjusting means for variably controlling the time duration of the sample interval period during which the pressure within the expansion chamber is decreased.
Claim 10
Dependent Claim
56 words
A variable rate continuous flow condensation nuclei meter according to claim 8 wherein the sample interval periodicity adjusting means comprises replaceable capillary means for variably controlling the size of a venting passageway controlling the time duration of the expansion period provided by the means For suddenly decreasing the pressure within the interior of the expansion chamber.
Claim 11
Dependent Claim
89 words
A variable rate continuous flow condensation nuclei meter according to claim 6 further including humidifier means connected in the inlet path for the sample gaseous atmosphere being monitored in advance of the expansion chamber, and wherein the means for variably controlling the flow rate of the gaseous atmosphere being monitored through the condensation nuclei meter comprises adjustable flow regulating means connected in a common passageway intermediate the common connection point of the bypass path to the outlet of the outlet valving means and the source of low pressure gas.
Claim 12
Dependent Claim
101 words
A variable rate continuous flow condensation nuclei meter according to claim 3 wherein said means for suddenly decreasing the pressure in the expansion chamber comprises a third access path to the expansion chamber, a flexible closure member closing said third access path, means defining an expansion cavity into which said flexible closure member can be suddenly expanded to thereby produce a sudden decrease in pressure in the expansion chamber during the sample interval, and means for expanding said flexible closure member into the expansion cavity during the sample interval and thereafter allowing it to return to its normal quiescent unstretched condition.
Claim 13
Dependent Claim
83 words
A variable rate continuous flow condensation nuclei meter according to claim 11 further including sample interval time period adjusting means coupled to the means for expanding said flexible closure member into the expansion cavity, said sample interval time period adjusting means serving to adjust the time interval required for the flexible closure member to return from its expanded condition to its normal quiescent unstretched condition whereby a wide range of different condensation nuclei concentrations readily and accurately can be measured with the meter.
Claim 14
Dependent Claim
94 words
A variable rate continuous flow condensation nuclei meter according to claim 12 wherein the sample interval time period adjusting means comprises a venting passageway connected intermediate the expansion cavity and a source of higher pressure gas, and means interposed in said venting passageway for adjustably controlling the flow rate of gases through the venting passageway to thereby variably control the time period required for the expansion cavity to be returned to an equilibrium condition relative to the interior of the expansion chamber at which point the closure member returns to its normal quiescent condition.
Claim 15
Dependent Claim
79 words
A variable rate continuous flow condensation nuclei meter according to claim 13 wherein said means for expanding said flexible closure member into the expansion cavity comprises rotary valve means for periodically subjecting the flexible closure member and the expansion cavity to a source of low pressure gas whereby a pressure differential is produced across the flexible closure member to cause it suddenly to expand into the expansion cavity thereby producing a sudden decrease in pressure in the expansion chamber.
Claim 16
Dependent Claim
88 words
A variable rate continuous flow condensation nuclei meter according to claim 14 wherein said expansion cavity is defined by a body member having a quasispherical cavity formed therein which has a flat neoprene member that comprises the flexible closure member extending across a diameter of the quasispherical cavity, said body member having a venting chamber to which the venting passageway is connected together with an access port to the rotary valve means, and a plurality of venting ports extending between the venting chamber and the quasispherical expansion cavity.
Claim 17
Dependent Claim
44 words
A variable rate continuous flow condensation nuclei meter according to claim 15 wherein the means interposed in the venting passageway for adjustably controlling the flow rate through the venting passageway comprises at least one capillary tube having one end exposed to atmospheric pressure gas.
Claim 18
Dependent Claim
78 words
A variable rate continuous flow condensation nuclei meter according to claim 11 wherein said means for expanding said flexible closure member into the expansion cavity comprises rotary valve means for periodically subjecting the flexible closure member and the expansion cavity to a source of low pressure whereby a pressure differential is produced across the flexible closure member to cause it suddenly to expand into the expansion cavity thereby producing a sudden decrease in pressure in the expansion chamber.
Claim 19
Dependent Claim
139 words
A variable rate continuous flow condensation nuclei member according to claim 17 wherein said rotary valve member comprises a valve body member having a central cylindrical bore and first and second passageways formed therein, a hollow cylindrical rotor member rotatably supported in the central bore and having an access opening therein axially aligned with the first and second passageways in the valve body member, said second passageway providing communication to the expansion cavity and said first passageway providing communication to the source of low pressure gas, and means for rotating said rotor member in a direction whereby the access opening therein periodically is radially aligned with the first and second passageways in that order in a serial manner and at a speed suitably proportioned to the range of flow rates of the sample gaseous atmosphere through the expansion chamber.
Claim 20
Dependent Claim
51 words
A variable rate continuous flow condensation nuclei meter according to claim 18 further including control valve means disposed in the first passageway intermediate the valve rotor member and the source of low-pressure gas for adjusting the pressure of the gas to which the interior of the hollow rotor member is exposed.
Claim 21
Dependent Claim
73 words
A variable rate continuous flow condensation nuclei meter according to claim 19 further including sample interval time period adjusting means coupled to the expansion cavity, said sample interval time period adjusting means serving to adjust the time interval required for the flexible closure member to return from its expanded condition to its normal quiescent condition whereby a wide range of different condensation nuclei concentrations readily and accurately can be measured with the meter.
Claim 22
Dependent Claim
95 words
A variable rate continuous flow condensation nuclei meter according to claim 20 wherein the sample interval time period adjusting means comprises a venting passageway connected intermediate the expansion cavity and a source of higher pressure gas, and means interposed in said venting passageway for adjustably controlling the flow rate of gases through the venting passageway to thereby variably control the time period required for the expansion cavity to be returned to an equilibrium condition relative to the interior of the expansion chamber at which point the closure member returns to its normal quiescent unstretched condition.
Claim 23
Dependent Claim
141 words
A variable rate continuous flow condensation nuclei member according to claim 21 wherein said expansion cavity is defined by a body member having a quasispherical cavity formed therein which has a flat neoprene member that comprises the flexible closure member extending across a diameter of the quasispherical cavity, said body member having a venting chamber to which the venting passageway is connected together with an access port to the rotary valve means, and a plurality of venting ports extending between the venting chamber and the quasispherical expansion cavity, the means interposed in the venting passageway for adjustably controlling the flow rate through the venting passageway comprises a plurality of capillary tubes each having one end exposed to atmospheric pressure gas, and means for selectively connecting in one of the capillary tubes in the venting passageway to control the flow rate therethrough.
Claim 24
Dependent Claim
52 words
A variable rate continuous flow condensation nuclei meter according to claim 22 further including control valve means disposed in the first passageway intermediate the valve rotor member and the source of low pressure gas for adjusting the pressure of the gas to which the interior of the holloW rotor member is exposed.
Claim 25
Dependent Claim
102 words
A variable rate continuous flow condensation nuclei member according to claim 23 further including means in the bypass flow path for restricting the flow rate through the bypass flow path relative to the expansion chamber during open intervals of the inlet and outlet passageway valving means whereby during such intervals a portion of the gaseous atmosphere being monitored flows through the expansion chamber, and during the sample interval substantially all flow takes place through the bypass path and a continuous flow rate is maintained through the condensation nuclei meter over a complete operating cycle and from one operating cycle to the next.
Claim 26
Dependent Claim
254 words
A wide range condensation nuclei meter comprising housing means defining an expansion chamber, means defining inlet and outlet passageways to said expansion chamber for introducing into and withdrawing from said expansion chamber specimens of an atmosphere to be monitored for condensation nuclei during each measurement cycle, valving means disposed in said inlet and outlet passageways for selectively opening and closing the passageways, means providing for differential flow of a sample gaseous atmosphere from a sample intake means for the meter through the expansion chamber with the valving means in an open condition, said inlet and outlet valving means being periodically operated for at least a short time duration sample interval for isolating a specimen of a gaseous atmosphere to be monitored in the expansion chamber during the sample interval at which point the pressure in the expansion chamber is suddenly decreased, radiant energy irradiating and detecting means viewing the interior of the expansion chamber and operative during the sample interval to derive an output electric signal representative of the intensity of the radiant energy modified by small liquid droplets formed on the condensation nuclei as centers upon the occurrence of the sudden decrease in pressure in the expansion chamber, the magnitude of the output electric signal thus derived comprising a measure of the number of condensation nuclei contained in the specimen of the gaseous atmosphere being monitored, and sample interval periodicity adjusting means for variably controlling the time duration of the sample interval period during which the pressure within the expansion chamber is decreased.
Claim 27
Dependent Claim
254 words
A wide range condensation nuclei meter comprising housing means defining an expansion chamber, means defining inlet and outlet passageways to said expansion chamber for introducing into and withdrawing from said expansion chamber specimens of an atmosphere to be monitored for condensation nuclei during each measurement cycle, valving means disposed in said inlet and outlet passageways for selectively opening and closing the passageways, means providing for differential flow of a sample gaseous atmosphere from a sample intake means for the meter through the expansion chamber with the valving means in an open condition, said inlet and outlet valving means being periodically operated for at least a short time duration sample interval for isolating a specimen of a gaseous atmosphere to be monitored in the expansion chamber during the sample interval at which point the pressure in the expansion chamber is suddenly decreased, radiant energy irradiating and detecting means viewing the interior of the expansion chamber and operative during the sample interval to derive an output electric signal representative of the intensity of the radiant energy modified by small liquid droplets formed on the condensation nuclei as centers upon the occurrence of the sudden decrease in pressure in the expansion chamber, the magnitude of the output electric signal thus derived comprising a measure of the number of condensation nuclei contained in the specimen of the gaseous atmosphere being monitored, and sample interval periodicity adjusting means for variably controlling the time duration of the sample interval period during which the pressure within the expansion chamber is decreased.
Claim 28
Dependent Claim
51 words
A wide range condensation nuclei meter according to claim 25 wherein the sample interval periodicity adjusting means comprises replaceable capillary means for variably controlling the size of a venting passageway that in turn controls the time duration of the expansion period provided while the pressure in the expansion chamber is decreased.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |