US20010032479A1 - Apparatus for analysis of impurities in liquid carbon dioxide - Google Patents

Apparatus for analysis of impurities in liquid carbon dioxide Download PDF

Info

Publication number
US20010032479A1
US20010032479A1 US09/886,098 US88609801A US2001032479A1 US 20010032479 A1 US20010032479 A1 US 20010032479A1 US 88609801 A US88609801 A US 88609801A US 2001032479 A1 US2001032479 A1 US 2001032479A1
Authority
US
United States
Prior art keywords
impurities
frozen
nozzle
liquid
snow
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
US09/886,098
Other versions
US6405560B2 (en
Inventor
Charles Bowers
Wilfried Krone-Schmidt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bruker Nano Inc
BOC Inc
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US09/886,098 priority Critical patent/US6405560B2/en
Publication of US20010032479A1 publication Critical patent/US20010032479A1/en
Application granted granted Critical
Publication of US6405560B2 publication Critical patent/US6405560B2/en
Assigned to BOC, INC. reassignment BOC, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ECO-SNOW SYSTEMS, INC.
Assigned to LINDE LLC reassignment LINDE LLC LICENSE (SEE DOCUMENT FOR DETAILS). Assignors: RAVE N.P., INC.
Assigned to RAVE N.P., INC. reassignment RAVE N.P., INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: LINDE LLC
Assigned to COMVEST CAPITAL, LLC reassignment COMVEST CAPITAL, LLC SECURITY AGREEMENT Assignors: RAVE N.P., INC.
Assigned to BRIDGE BANK, NATIONAL ASSOCIATION reassignment BRIDGE BANK, NATIONAL ASSOCIATION SECURITY AGREEMENT Assignors: RAVE N.P., INC.
Assigned to AVIDBANK CORPORATE FINANCE, A DIVISION OF AVIDBANK reassignment AVIDBANK CORPORATE FINANCE, A DIVISION OF AVIDBANK SECURITY AGREEMENT Assignors: RAVE N.P., INC.
Assigned to RAVE N.P., INC. reassignment RAVE N.P., INC. RELEASE BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: BRIDGE BANK, NATIONAL ASSOCIATION
Assigned to RAVE, LLC reassignment RAVE, LLC RELEASE BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: COMVEST CAPITAL, LLC
Assigned to RAVE N.P., INC. reassignment RAVE N.P., INC. RELEASE BY SECURED PARTY (SEE DOCUMENT FOR DETAILS). Assignors: AVIDBANK SPECIALTY FINANCE, A DIVISION OF AVIDBANK
Anticipated expiration legal-status Critical
Assigned to Bruker Nano, Inc. reassignment Bruker Nano, Inc. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: RAVE DIAMOND TECHNOLOGIES INC., RAVE LLC, RAVE N.P., INC.
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G01N1/40—Concentrating samples
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/02—Devices for withdrawing samples
    • G01N1/22—Devices for withdrawing samples in the gaseous state
    • G01N1/2226—Sampling from a closed space, e.g. food package, head space
    • G01N2001/2238—Sampling from a closed space, e.g. food package, head space the gas being compressed or pressurized
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • G01N1/40—Concentrating samples
    • G01N1/4022—Concentrating samples by thermal techniques; Phase changes
    • G01N2001/4027—Concentrating samples by thermal techniques; Phase changes evaporation leaving a concentrated sample

Definitions

  • This invention relates to an apparatus for analysing impurity levels in liquid carbon dioxide (CO 2 ).
  • CO 2 snow (frozen CO 2 ) is used as a medium to determine non-volatile impurities in the CO 2 snow, and consequently determine the purity of the liquid CO 2 .
  • Liquid CO 2 is expanded in specially designed primary and secondary nozzles to produce low-density and low-velocity CO 2 snow.
  • the impurities initially contained in the liquid CO 2 are trapped inside of the frozen CO 2 , which is preferably collected in a clean container. According to one preferred embodiment, the container is emptied on top of a high purity surface.
  • the impurities are concentrated on the surface, since these impurities are non-volatile and do not escape with the CO 2 gas formed as the CO 2 snow is heated by the ambient temperature to its sublimation point. After all of the CO 2 snow has sublimed, the surface can be analysed by standard methods to determine quantity and composition of the impurities. The determination and quantification of non-volatile impurities, such as organic oils and greases, in the CO 2 supply that feeds, for example, cleaning systems utilizing liquid CO 2 , is thus made possible.
  • the system according to the invention has a primary nozzle and a secondary nozzle.
  • the primary nozzle is connected to a liquid CO 2 source via one or more small orifices having a suitable shape, for example substantially round, a slit or an annulus shape (an annular slit).
  • Liquid CO 2 is expanded after the orifices, and the expansion causes the liquid to freeze into snow particles.
  • the primary nozzle is arranged to project the snow particles at a certain angle into the secondary nozzle.
  • the snow particles collide with each other and the walls of the secondary nozzle, and the secondary nozzle geometry is designed to cause the snow to have multiple collisions with these walls.
  • the collisions reduce the velocity of the snow and cause many snow particles to stick together further reducing the snow velocity.
  • the container is emptied onto a high purity surface, and as the snow sublimes from the surface, the non-volatile impurities remain on the surface and accumulate in high concentrations.
  • FIG. 1 is a schematic side view of a system according to the invention
  • FIG. 2 is a schematic elevational side view of the system shown in FIG. 1,
  • FIG. 3A is a schematic elevational side view of a first embodiment of the secondary nozzle
  • FIG. 3B is a schematic elevational side view of a second embodiment of the secondary nozzle.
  • FIG. 3C is a schematic elevational side view of a third embodiment of the secondary nozzle.
  • the system 1 has a primary nozzle 10 and a secondary nozzle 20 .
  • the primary nozzle 10 has one or more small orifices 5 arranged upstream of the primary nozzle, and is connected to a liquid CO 2 source (not shown) via a valve (not shown).
  • the orifices are of suitable shape for example substantially round, a slit or an annulus shape (an annular slit).
  • a fitting 15 for example a VCR fitting, is arranged between the primary nozzle 10 and the liquid CO 2 source. Liquid CO 2 is expanded in the orifices 5 , and the expansion causes the liquid to freeze into snow particles.
  • the primary nozzle 10 is mounted to the secondary nozzle via a sealed opening 12 and is arranged to project the snow particles at a certain angle a into the secondary nozzle 20 .
  • the secondary nozzle has side walls 25 , a bottom wall 26 and a discharge opening 27 .
  • the side walls form a closed cross-section and the bottom wall is sealingly fastened to one end of the side walls.
  • the secondary nozzle 20 is fabricated from a solid piece of material, for example by milling and drilling.
  • the snow particles collide with each other, and the side and bottom walls of the secondary nozzle 20 .
  • the secondary nozzle geometry is designed to cause the snow particles to have multiple collisions with the walls, examples of preferred embodiments are shown in FIGS. 3A to 3 C.
  • the collisions reduce the velocity of the snow and cause many snow particles to stick together, further reducing the snow velocity.
  • the angle ⁇ is chosen so that a maximum number of collisions is obtained without clogging the secondary nozzle with frozen CO 2 .
  • a preferred angle is 45 degrees, but any angle between 1 and 89 degrees may be used.
  • the cross-section of the secondary nozzle 20 is circular, oval, rectangular, quadratic or any geometry which will provide the necessary collisions.
  • the collection means is any suitable container, which can hold the frozen CO 2 without spilling or contaminating it.
  • the collected snow is preferably deposited onto a clean surface (not shown) and, as the snow sublimes off the surface, the non-volatile impurities remain on the surface and accumulate in high concentrations.
  • the invention thus uses CO 2 snow as a medium to determine non-volatile impurities in CO 2 snow, and consequently determine the purity of liquid CO 2 .
  • each of the primary and secondary nozzles are of fixed mechanical dimensions they can be calibrated to measure only one property, either mass loss of the bulk material or collection time, and a second measurement of the weight of the accumulated impurity or volume and density can then be used to calculate the exact concentration of impurities.
  • the method used by the invention preferably includes the steps of
  • a collecting means which is any suitable clean container, such as a glass beaker,
  • the frozen CO 2 from the secondary nozzle 20 may be led directly to a real-time analysis means (not shown), for direct analysis.
  • the primary nozzle 10 , the secondary nozzle 20 and the real-time analysis means are preferably assembled as one unit, to facilitate field use.
  • a CO 2 cylinder which was known to contain an impurity, was weighed, the analysis nozzles (primary nozzle and secondary nozzle) connected to it and 2 pounds of liquid CO 2 were expanded through the nozzle.
  • a 1 liter beaker was filled with snow, inverted onto a Si wafer, and the snow was allowed to sublime.
  • the total contaminated area can be calculated from the diameter of about 3.5′′ or 9 cm, equalling 64 cm 2 .
  • the volume of this material is then 196 ⁇ 10-8 cm times 64 cm 2 equalling 1.25 ⁇ 10-4 cm 3 . Assuming a density of 0.8 g/ml for organic oils gives 1 ⁇ 10-4 g, or 0.1 mg.
  • contamination concentrated in the above described way may be further analysed by standard analysis methods like Fourier Transform Infrared Spectroscopy (FTIR), Mass Spectrometry, Gas Chromatography (“HPGC”), Residual Gas Analysis (RGA), film thickness measurements etc., to determine the exact nature and proportions of the impurity.
  • FTIR Fourier Transform Infrared Spectroscopy
  • HPGC Gas Chromatography
  • RAA Residual Gas Analysis
  • film thickness measurements etc.

Abstract

Liquid CO2 is expanded in specially designed primary and secondary nozzles to produce frozen solid CO2. The impurities initially contained in the liquid CO2 are trapped inside of the frozen CO2, which is collected in a clean container. The container is emptied on top of a high purity surface. The impurities are concentrated on the surface, since these impurities are non-volatile and do not escape with the CO2 gas formed as the frozen CO2 is heated by the ambient temperature to its sublimation point. After all of the frozen CO2 has sublimed, the surface can be analysed by standard analysis methods to determine quantity and composition of the impurities. The determination and quantification of non-volatile impurities, such as organic oils and greases, in the CO2 supply that feeds, for example, cleaning systems utilizing CO2, is thus made possible.

Description

    REFERENCE TO RELATED APPLICATION
  • This is a continuation of application no. 09/411,396, filed Oct. 4, 1999.[0001]
    • BACKGROUND OF THE INVENTION
  • 1. Field of the Invention [0002]
  • This invention relates to an apparatus for analysing impurity levels in liquid carbon dioxide (CO[0003] 2).
  • 2. Description of the Prior Art [0004]
  • Previous methods of separating impurities from liquid CO[0005] 2 rely primarily on High Pressure Liquid Chromatography (HPLC) to separate out the constituents of impurities contained in the liquid CO2, for analysis of the impurity levels. The equipment necessary to carry out these methods is expensive and has an inherent lower resolution, quantification, and accuracy than that which is required for many applications. Also, some impurities may not be able to be separated using this technique, rendering the HPLC method useless for detecting the presence of these impurities. Furthermore, the equipment has to be calibrated frequently, usually just prior to use.
    • SUMMARY OF THE INVENTION
  • It is an object of the invention to mitigate and/or obviate the drawbacks of the prior art mentioned above, and provide an easy to use and inexpensive apparatus for determining the impurity levels in liquid CO[0006] 2. In the invention, CO2 snow (frozen CO2) is used as a medium to determine non-volatile impurities in the CO2 snow, and consequently determine the purity of the liquid CO2. Liquid CO2 is expanded in specially designed primary and secondary nozzles to produce low-density and low-velocity CO2 snow. The impurities initially contained in the liquid CO2 are trapped inside of the frozen CO2, which is preferably collected in a clean container. According to one preferred embodiment, the container is emptied on top of a high purity surface. The impurities are concentrated on the surface, since these impurities are non-volatile and do not escape with the CO2 gas formed as the CO2 snow is heated by the ambient temperature to its sublimation point. After all of the CO2 snow has sublimed, the surface can be analysed by standard methods to determine quantity and composition of the impurities. The determination and quantification of non-volatile impurities, such as organic oils and greases, in the CO2 supply that feeds, for example, cleaning systems utilizing liquid CO2, is thus made possible.
  • The system according to the invention has a primary nozzle and a secondary nozzle. The primary nozzle is connected to a liquid CO[0007] 2 source via one or more small orifices having a suitable shape, for example substantially round, a slit or an annulus shape (an annular slit). Liquid CO2 is expanded after the orifices, and the expansion causes the liquid to freeze into snow particles. The primary nozzle is arranged to project the snow particles at a certain angle into the secondary nozzle. The snow particles collide with each other and the walls of the secondary nozzle, and the secondary nozzle geometry is designed to cause the snow to have multiple collisions with these walls. The collisions reduce the velocity of the snow and cause many snow particles to stick together further reducing the snow velocity. Thus, the snow is easily collected in a container for analysis. The container is emptied onto a high purity surface, and as the snow sublimes from the surface, the non-volatile impurities remain on the surface and accumulate in high concentrations.
  • The advantage of this system is the simplicity of use and low cost, since it does not require expensive analytical equipment. This simple and inexpensive method enables part-per-billion (ppb) resolution of non-volatile impurities. [0008]
  • Further features of the invention will be described or will become apparent in the course of the following detailed description.[0009]
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • In order that the invention may be more clearly understood, the preferred embodiment thereof will now be described in detail by way of example, with reference to the accompanying drawing, in which: [0010]
  • FIG. 1 is a schematic side view of a system according to the invention, [0011]
  • FIG. 2 is a schematic elevational side view of the system shown in FIG. 1, [0012]
  • FIG. 3A is a schematic elevational side view of a first embodiment of the secondary nozzle, [0013]
  • FIG. 3B is a schematic elevational side view of a second embodiment of the secondary nozzle, and [0014]
  • FIG. 3C is a schematic elevational side view of a third embodiment of the secondary nozzle.[0015]
    • DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
  • As shown in FIGS. 1 and 2, the system [0016] 1 according to the invention has a primary nozzle 10 and a secondary nozzle 20. The primary nozzle 10 has one or more small orifices 5 arranged upstream of the primary nozzle, and is connected to a liquid CO2 source (not shown) via a valve (not shown). The orifices are of suitable shape for example substantially round, a slit or an annulus shape (an annular slit). A fitting 15, for example a VCR fitting, is arranged between the primary nozzle 10 and the liquid CO2 source. Liquid CO2 is expanded in the orifices 5, and the expansion causes the liquid to freeze into snow particles. The primary nozzle 10 is mounted to the secondary nozzle via a sealed opening 12 and is arranged to project the snow particles at a certain angle a into the secondary nozzle 20. The secondary nozzle has side walls 25, a bottom wall 26 and a discharge opening 27. The side walls form a closed cross-section and the bottom wall is sealingly fastened to one end of the side walls. Alternatively, the secondary nozzle 20 is fabricated from a solid piece of material, for example by milling and drilling. The snow particles collide with each other, and the side and bottom walls of the secondary nozzle 20. The secondary nozzle geometry is designed to cause the snow particles to have multiple collisions with the walls, examples of preferred embodiments are shown in FIGS. 3A to 3C. The collisions reduce the velocity of the snow and cause many snow particles to stick together, further reducing the snow velocity. The angle α is chosen so that a maximum number of collisions is obtained without clogging the secondary nozzle with frozen CO2. A preferred angle is 45 degrees, but any angle between 1 and 89 degrees may be used. The cross-section of the secondary nozzle 20 is circular, oval, rectangular, quadratic or any geometry which will provide the necessary collisions. Thus, the snow is easily discharged through the discharge opening 27 and collected in a collection means 30 for analysis. The collection means is any suitable container, which can hold the frozen CO2 without spilling or contaminating it. The collected snow is preferably deposited onto a clean surface (not shown) and, as the snow sublimes off the surface, the non-volatile impurities remain on the surface and accumulate in high concentrations.
  • The invention thus uses CO[0017] 2 snow as a medium to determine non-volatile impurities in CO2 snow, and consequently determine the purity of liquid CO2.
  • Since each of the primary and secondary nozzles are of fixed mechanical dimensions they can be calibrated to measure only one property, either mass loss of the bulk material or collection time, and a second measurement of the weight of the accumulated impurity or volume and density can then be used to calculate the exact concentration of impurities. [0018]
  • The method used by the invention preferably includes the steps of [0019]
  • connecting a liquid CO[0020] 2 supply to the primary nozzle,
  • expanding liquid CO[0021] 2 in the primary nozzle to produce frozen solid CO2, which is projected further into the secondary nozzle, to produce low-density and low-velocity CO2 snow; the impurities initially contained in the liquid CO2 are trapped inside of the frozen CO2,
  • collecting the CO[0022] 2 snow in a collecting means, which is any suitable clean container, such as a glass beaker,
  • preferably emptying the container, after collecting a sufficient quantity, onto a high purity surface, such as a polished silicon wafer, leaving the impurities concentrated on the wafer, since these impurities are non-volatile and do not escape with the CO[0023] 2 gas
  • analysing the surface by standard methods, after all of the CO[0024] 2 snow has sublimed, to determine quantity and composition of the impurity.
  • Alternatively, the frozen CO[0025] 2 from the secondary nozzle 20 may be led directly to a real-time analysis means (not shown), for direct analysis. The primary nozzle 10, the secondary nozzle 20 and the real-time analysis means are preferably assembled as one unit, to facilitate field use.
  • Thus, the determination and quantification of non-volatile impurities, such as organic oils and greases, in the CO[0026] 2 supply that feeds, for example, cleaning systems utilizing liquid CO2, is made possible. The user of the system according to the invention can easily verify the purity of the CO2 prior to using it for cleaning operations.
    • EXAMPLE
  • A CO[0027] 2 cylinder, which was known to contain an impurity, was weighed, the analysis nozzles (primary nozzle and secondary nozzle) connected to it and 2 pounds of liquid CO2 were expanded through the nozzle. A 1 liter beaker was filled with snow, inverted onto a Si wafer, and the snow was allowed to sublime.
  • The resulting, highly visible layer was then analysed by ellypsometry and weighing. [0028]
  • Four spots on the wafer were chosen for ellipsometer analysis: the centre, halfway to the edge, a thicker hazy spot and one spot near the edge. The thickness were recorded as follows: 141 Å, 163 Å, 260 Å, and 220 Å, respectively. On first order, the average of these values gives 196 ű54 Å. [0029]
  • The total contaminated area can be calculated from the diameter of about 3.5″ or 9 cm, equalling 64 cm[0030] 2. The volume of this material is then 196×10-8 cm times 64 cm2 equalling 1.25×10-4 cm3. Assuming a density of 0.8 g/ml for organic oils gives 1×10-4 g, or 0.1 mg.
  • The wafer was then weighed on a balance, rinsed with acetone, and weighed again; the net weight was 0.2 mg +0 −0.1 mg. This contaminant was collected from 2 pounds of liquid CO[0031] 2. Thus, we can calculate 1×10-4 g divided by 1000 g equals 1×10-7, or 100 ppb.
  • Both methods calculated an impurity level of 100 ppb. Based on this and similar results, it is believed that contamination levels of less than 10 ppb can be visually detected and with appropriate instrumentation quantified. The procedure may be repeated multiple times to give yet higher degrees of resolution. [0032]
  • It will be appreciated that the above description relates to the preferred embodiment by way of example only. Many variations on the invention will be obvious to those knowledgeable in the field, and such obvious variations are within the scope of the invention as described and claimed, whether or not expressly described. [0033]
  • For example, contamination concentrated in the above described way, may be further analysed by standard analysis methods like Fourier Transform Infrared Spectroscopy (FTIR), Mass Spectrometry, Gas Chromatography (“HPGC”), Residual Gas Analysis (RGA), film thickness measurements etc., to determine the exact nature and proportions of the impurity. [0034]

Claims (3)

What is claimed as the invention is:
1. An apparatus for separation of non-volatile impurities from liquid carbon dioxide, said apparatus comprising:
a primary nozzle, connected to a liquid CO2 source,
at least one small orifice, arranged in a first conduit upstream of said primary nozzle, and arranged to expand said liquid CO2 in said primary nozzle to form frozen solid CO2,
a secondary nozzle arranged so that said first nozzle projects said frozen solid CO2 at an acute angle into said secondary nozzle; and
a collection means, positioned to receive said frozen CO2 from a discharge opening of said secondary nozzle.
2. An apparatus according to
claim 1
, wherein said primary nozzle is connected to said liquid CO2 source via said first conduit, said first conduit having a valve, which may be opened or closed to permit or restrict the flow of CO2 through said first conduit.
3. An apparatus according to
claim 2
, wherein said secondary nozzle has side walls, forming a closed cross-section, a bottom wall, sealingly attached to one end of said side walls, and wherein said primary nozzle is mounted to said secondary nozzle via a sealed opening and is arranged to project the frozen CO2 at a preset angle into said secondary nozzle, to cause the frozen CO2 to collide with said walls and said bottom wall to lower the velocity of the individual particles of the frozen CO2.
US09/886,098 1999-10-04 2001-06-22 Apparatus for analysis of impurities in liquid carbon dioxide Expired - Lifetime US6405560B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US09/886,098 US6405560B2 (en) 1999-10-04 2001-06-22 Apparatus for analysis of impurities in liquid carbon dioxide

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US09/411,396 US6276169B1 (en) 1999-10-04 1999-10-04 Apparatus and method for analysis of impurities in liquid carbon dioxide
US09/886,098 US6405560B2 (en) 1999-10-04 2001-06-22 Apparatus for analysis of impurities in liquid carbon dioxide

Related Parent Applications (2)

Application Number Title Priority Date Filing Date
US09/411,396 Continuation US6276169B1 (en) 1999-10-04 1999-10-04 Apparatus and method for analysis of impurities in liquid carbon dioxide
US09/411,396 Division US6276169B1 (en) 1999-10-04 1999-10-04 Apparatus and method for analysis of impurities in liquid carbon dioxide

Publications (2)

Publication Number Publication Date
US20010032479A1 true US20010032479A1 (en) 2001-10-25
US6405560B2 US6405560B2 (en) 2002-06-18

Family

ID=23628744

Family Applications (2)

Application Number Title Priority Date Filing Date
US09/411,396 Expired - Lifetime US6276169B1 (en) 1999-10-04 1999-10-04 Apparatus and method for analysis of impurities in liquid carbon dioxide
US09/886,098 Expired - Lifetime US6405560B2 (en) 1999-10-04 2001-06-22 Apparatus for analysis of impurities in liquid carbon dioxide

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US09/411,396 Expired - Lifetime US6276169B1 (en) 1999-10-04 1999-10-04 Apparatus and method for analysis of impurities in liquid carbon dioxide

Country Status (1)

Country Link
US (2) US6276169B1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060124156A1 (en) * 2004-12-13 2006-06-15 Cool Clean Technologies, Inc. Carbon dioxide snow apparatus

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TWI312067B (en) * 2002-01-22 2009-07-11 Praxair Technology Inc Method for analyzing impurities in carbon dioxide
US20190170441A1 (en) * 2017-12-05 2019-06-06 Larry Baxter Pressure-Regulated Melting of Solids with Warm Fluids
US20190170440A1 (en) * 2017-12-05 2019-06-06 Larry Baxter Pressure-Regulated Melting of Solids

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3124442A (en) * 1964-03-10 Method and apparatus for manufacturing an aerosol
US4337071A (en) * 1979-08-02 1982-06-29 Yang Lien C Air purification system using cryogenic techniques
FR2706990B1 (en) * 1993-06-23 1995-08-04 Carboxyque Francaise
US5868003A (en) * 1997-07-14 1999-02-09 Praxair Technology, Inc. Apparatus for producing fine snow particles from a flow liquid carbon dioxide
US6023941A (en) * 1998-07-22 2000-02-15 Praxair Technology, Inc. Horizontal carbon dioxide snow horn with adjustment for desired snow
US6116049A (en) * 1998-11-13 2000-09-12 The United States Of America As Represented By The Secretary Of Transportation Adiabatic expansion nozzle

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060124156A1 (en) * 2004-12-13 2006-06-15 Cool Clean Technologies, Inc. Carbon dioxide snow apparatus
US7293570B2 (en) * 2004-12-13 2007-11-13 Cool Clean Technologies, Inc. Carbon dioxide snow apparatus

Also Published As

Publication number Publication date
US6405560B2 (en) 2002-06-18
US6276169B1 (en) 2001-08-21

Similar Documents

Publication Publication Date Title
Allen Particle size measurement
US4783318A (en) Apparatus for environmental leaching testing
Willeke et al. Improved aerosol collection by combined impaction and centrifugal motion
Markovic et al. Characterization and optimization of an online system for the simultaneous measurement of atmospheric water-soluble constituents in the gas and particle phases
CA2328244A1 (en) Device for the collection, storage and/or transport of gas samples
US6405560B2 (en) Apparatus for analysis of impurities in liquid carbon dioxide
AU667934B2 (en) Equipment for sampling and work-up for analysis of PAH and other organic compounds, and hydrogen fluoride and sulphur oxides
CA2133343A1 (en) Measuring and monitoring the size of particulate material
CA2176699A1 (en) Mid-stream fluid sampler
Ekström et al. International studies to compare methods for personal sampling of bitumen fumes
Tsai et al. Development of diffuse reflectance infrared Fourier transform spectroscopy for the rapid characterization of aerosols
Berner The collection of fog droplets by a jet impaction stage
Zenchelsky et al. The organic component of wind-blown soil aerosol as a function of wind velocity
Bardwell et al. A technique using high‐flow, dichotomous filter packs for measuring major atmospheric chemical constituents
Bitterli et al. Determination of metals in airborne particles by electrothermal vaporization inductively coupled plasma mass spectrometry after accumulation by electrostatic precipitation
DeFelice et al. Mechanisms for the operation of three cloudwater collectors: comparison of mountain-top results
Ehhalt In situ measurements of stratospheric trace constituents
Steffen et al. Mercury throughout polar sunrise 2002
Hewitt Comparison of methods for sampling vadose zone soils for determination of trichloroethylene
JPH0843278A (en) Sampler that discharges supercooled air for sampling mixed contaminant
US6487921B1 (en) Fluidization segregation tester
De Santis et al. Negative interference of Teflon sampling devices in the determination of nitric acid and particulate nitrate
Messerle et al. An inexpensive sample holder for storage and introduction of air-sensitive organometallic compounds into a mass spectrometer with inert-atmosphere blanketing
EP0398856A3 (en) An apparatus incorporating a measuring head
Cartan et al. Average particle size measurement

Legal Events

Date Code Title Description
STCF Information on status: patent grant

Free format text: PATENTED CASE

AS Assignment

Owner name: BOC, INC., NEW JERSEY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:ECO-SNOW SYSTEMS, INC.;REEL/FRAME:013798/0064

Effective date: 20030708

FEPP Fee payment procedure

Free format text: PAYER NUMBER DE-ASSIGNED (ORIGINAL EVENT CODE: RMPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

AS Assignment

Owner name: LINDE LLC, NEW JERSEY

Free format text: LICENSE;ASSIGNOR:RAVE N.P., INC.;REEL/FRAME:024823/0796

Effective date: 20100813

AS Assignment

Owner name: RAVE N.P., INC., FLORIDA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:LINDE LLC;REEL/FRAME:024838/0193

Effective date: 20100630

AS Assignment

Owner name: COMVEST CAPITAL, LLC, FLORIDA

Free format text: SECURITY AGREEMENT;ASSIGNOR:RAVE N.P., INC.;REEL/FRAME:025387/0886

Effective date: 20101108

AS Assignment

Owner name: BRIDGE BANK, NATIONAL ASSOCIATION, CALIFORNIA

Free format text: SECURITY AGREEMENT;ASSIGNOR:RAVE N.P., INC.;REEL/FRAME:030331/0646

Effective date: 20110901

AS Assignment

Owner name: AVIDBANK CORPORATE FINANCE, A DIVISION OF AVIDBANK

Free format text: SECURITY AGREEMENT;ASSIGNOR:RAVE N.P., INC.;REEL/FRAME:031597/0548

Effective date: 20131106

AS Assignment

Owner name: RAVE N.P., INC., CALIFORNIA

Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:BRIDGE BANK, NATIONAL ASSOCIATION;REEL/FRAME:031616/0248

Effective date: 20131113

FPAY Fee payment

Year of fee payment: 12

AS Assignment

Owner name: RAVE, LLC, FLORIDA

Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:COMVEST CAPITAL, LLC;REEL/FRAME:035664/0490

Effective date: 20150427

AS Assignment

Owner name: RAVE N.P., INC., FLORIDA

Free format text: RELEASE BY SECURED PARTY;ASSIGNOR:AVIDBANK SPECIALTY FINANCE, A DIVISION OF AVIDBANK;REEL/FRAME:048886/0669

Effective date: 20190402

AS Assignment

Owner name: BRUKER NANO, INC., FLORIDA

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:RAVE LLC;RAVE N.P., INC.;RAVE DIAMOND TECHNOLOGIES INC.;REEL/FRAME:050997/0604

Effective date: 20190402