Pneumatic concentric nebulizer with adjustable and capillaries

• US 5,884,846 A
• Filed: 09/18/1997
• Issued: 03/23/1999
• Est. Priority Date: 09/19/1996
• Status: Expired due to Fees

• Current Assignee: Hsiaoming Sherman Tan
• Original Assignee: Hsiaoming Sherman Tan
• Inventors: Tan, Hsiaoming Sherman
• Primary Examiner(s): Kashnikow, Andres
• Assistant Examiner(s): Douglas, Lisa Ann
• Application Number:
  US08/933,602
• Time in Patent Office: 551 Days
• Field of Search: 239/311, 239/314, 239/318, 239/338, 239/340, 239/346, 239/418, 239/423, 239/424, 239/DIG. 7, 239/433, 239/600, 261/78.2, 128/200.21
• US Class Current: 239/338
• CPC Class Codes: B05B 7/0475 with means for deflecting the peripheral gas flow towards the central liquid flow B05B7/0458 takes precedence
• CPC Class Codes: B05B 7/066 with an inner liquid outlet surrounded by at least one annular gas outlet

Abstract

A concentric nebulizer having applicability in inductively coupled plasma spectrometry is disclosed. The device features a nebulizer tube with a tapered front open end and mechanism for removing, replacing, and adjusting the position of central sample capillaries with respect to the opening in the front end to adjust such parameters as gas pressure, sample flow rates, and aerosol formation over a wide range. Devices constructed in accordance with the invention may operate at low gas pressure and are physically compatible to glass concentric nebulizers.

Claims

1. A pneumatic concentric nebulizer with an adjustable and replaceable central sample capillary comprising:

a central housing having an open rear end, an open front end, a bore extending from said rear end to said front end, and a gas entrance opening communicating with said bore, said gas entrance opening being adapted for gas-tight engagement with a source of pressurized gas for introducing pressurized gas into said housing;

a nebulizer tube having a rear gas entrance end, a forward gas expulsion end and an interior surface extending between said gas entrance and gas expulsion ends and defining a channel therebetween, said forward end terminating in a gas expulsion orifice;

nebulizer tube sealing means proximate to said front end of said housing for removably receiving and sealably engaging said nebulizer tube proximate its gas entrance end so that a gas tight seal is formed between said nebulizer tube and said housing when the apparatus is in use;

a central capillary having a sample intake port, a sample exit port, an outer wall, and an inner wall, said inner wall defining a sample channel that extends from said sample intake port to said sample exit port, said sample intake port being attachable to a source of sample to be nebulized;

capillary sealing means proximate to said rear end of said housing, said capillary sealing means being movable between an open position and a sealing position for slidably and removably receiving, and selectively sealably engaging, said capillary such that when said capillary sealing means are in the open position said sample exit port of said capillary may be received through said rear end of said housing and translated linearly forward within said housing toward said gas expulsion end of said nebulizer tube until a desired location for said sample exit port with respect to said gas expulsion orifice has been attained at which point said capillary sealing means can be moved into its sealing position to form a gas tight seal between said housing and said capillary so that when said nebulizer tube and said capillary are both sealably engaged by said housing, and pressurized gas is introduced into said housing through said gas entrance opening, the gas is expelled through said gas expulsion orifice of said nebulizer tube at a high enough velocity to create a low pressure system in the vicinity of said sample exit port of said capillary sufficient to draw sample from said capillary by free suction into the path of the exiting g as which in turn will nebulize the sample and propel it generally in the direction of the exiting gas.

2. The invention of claim 1 wherein said housing is substantially T-shaped and comprises a tube portion corresponding to the horizontal portion of the "T" and extending from said open rear end to said open front end, and further comprises a gas conduit depending from said tube portion which is in gas-tight fluid communication with said gas entrance opening and extends substantially perpendicularly from said tube portion to facilitate convenient connection of said housing to the source of pressurized gas.

3. The invention of claim 1 wherein said forward gas expulsion end of said nubulizer tube is tapered downward toward said orifice to form a substantially cone shaped nozzle.

4. The invention of claim 3 wherein the position of said sample exit port of said capillary is adjustable between positions beyond said gas expulsion orifice of said nebulizer tube and recessed with respect to said gas expulsion orifice to permit the user to attain various gas back pressures within said nebulizer tube and various nebulization effects.

5. The invention of claim 1 wherein said capillary sealing means is capable of receiving and sealably engaging capillaries of various inner and outer diameters.

6. A pneumatic concentric nebulizer with an adjustable and replaceable central sample capillary comprising:

a central housing having an open rear end, an open front end, and a bore extending from said rear end to said front end;

a nebulizer tube having a rear gas entrance end, a forward gas expulsion end and an interior surface extending between said gas entrance and gas expulsion ends and defining a channel therebetween, said forward end terminating in a gas expulsion orifice, said nebulizer tube further including an integral gas conduit depending therefrom which gas conduit is in fluid communication with said channel within said nebulizer tube and attachable to a source of pressurized gas so that pressurized gas can be introduced into said nebulizer tube;

nebulizer tube sealing means proximate to said front end of said housing for removably receiving and sealably engaging said nebulizer tube proximate its gas entrance end so that a gas tight seal is formed between said nebulizer tube and said housing when the apparatus is in use;

a central capillary having a sample intake port, a sample exit port, an outer wall, and an inner wall, said inner wall defining a sample channel that extends from said sample intake port to said sample exit port, said sample intake port being attachable to a source of sample to be nebulized;

capillary sealing means proximate to said rear end of said housing, said sealing means being movable between an open position and a sealing position for slidably and removably receiving, and selectively sealably engaging, said capillary such that when said capillary sealing means are in the open position said sample exit port of said capillary may be received through said rear end of said housing and translated linearly forward within said housing toward said gas expulsion end of said nebulizer tube until a desired location for said sample exit port with respect to said gas expulsion orifice has been attained at which point said capillary sealing means can be moved into its sealing position to form a gas tight seal between said housing and said capillary so that when said nebulizer tube and said capillary are both sealably engaged by said housing, and pressurized gas is introduced into said nebulizer tube through said integral gas conduit, the gas is expelled through said gas expulsion orifice of said nebulizer tube at a high enough velocity to create a low pressure system in the vicinity of said sample exit port of said capillary sufficient to draw sample from said capillary by free suction into the path of the exiting gas which in turn will nebulize the sample and propel it generally in the direction of the exiting gas.

7. The invention of claim 6 wherein said forward gas expulsion end of said nubulizer tube is tapered downward toward said orifice to form a substantially cone shaped nozzle.

8. The invention of claim 7 wherein said sample exit port of said capillary is movable between positions beyond said gas expulsion orifice of said nebulizer tube and recessed with respect to said gas expulsion orifice to permit the user to attain various gas back pressures within said nebulizer tube and various nebulization effects.

9. The invention of claim 6 wherein said capillary sealing means is capable of receiving and sealably engaging capillaries of various inner and outer diameters.

10. A pneumatic concentric nebulizer with an adjustable and replaceable central sample capillary comprising:

a central housing having an open rear end, an open front end, a bore extending from said rear end to said front end, and a gas entrance opening communicating with said bore, said gas entrance opening being adapted for gas-tight engagement with a source of pressurized gas for introducing pressurized gas into said housing;

a nebulizer tube having a rear gas entrance end, a forward gas expulsion end and an interior surface extending between said gas entrance and gas expulsion ends and defining a channel therebetween, said forward end terminating in a gas expulsion orifice;

nebulizer tube sealing means proximate to said front end of said housing for removably receiving and sealably engaging said nebulizer tube proximate its gas entrance end so that a gas tight seal is formed between said nebulizer tube and said housing when the apparatus is in use;

a central capillary having a sample intake port, a sample exit port, an outer wall, and an inner wall, said inner wall defining a sample channel that extends from said sample intake port to said sample exit port, said sample intake port being attachable to a source of sample to be pumped into said sample intake port, through said sample channel, and out said exit port to be nebulized;

capillary sealing means proximate to said rear end of said housing, said capillary sealing means being movable between an open position and a sealing position for slidably and removably receiving, and selectively sealably engaging, said capillary such that when said capillary sealing means are in the open position said sample exit port of said capillary may be received through said rear end of said housing and translated linearly forward within said housing toward said gas expulsion end of said nebulizer tube until a desired location for said sample exit port with respect to said gas expulsion orifice has been attained at which point said capillary sealing means can be moved into its sealing position to form a gas tight seal between said housing and said capillary so that when said nebulizer tube and said capillary are both sealably engaged by said housing, and pressurized gas is introduced into said housing through said gas entrance opening, the gas is expelled through said gas expulsion orifice of said nebulizer tube at a high enough velocity to nebulize and propel sample being pumped through said sample capillary into the path of the gas generally in the direction of the exiting gas.

11. The invention of claim 10 wherein said housing is substantially T-shaped and comprises a tube portion corresponding to the horizontal portion of the "T" and extending from said open rear end to said open front end, and further comprises a gas conduit depending from said tube portion which is in gas-tight fluid communication with said gas entrance opening and extends substantially perpendicularly from said tube portion to facilitate convenient connection of said housing to the source of pressurized gas.

12. The invention of claim 10 wherein said forward gas expulsion end of said nubulizer tube is tapered downward toward said orifice to form a substantially cone shaped nozzle.

13. The invention of claim 12 wherein the position of said sample exit port of said capillary is adjustable between positions beyond said gas expulsion orifice of said nebulizer tube and recessed with respect to said gas expulsion orifice to permit the user to attain various gas back pressures within said nebulizer tube and various nebulization effects.

14. The invention of claim 10 wherein said capillary sealing means is capable of receiving and sealably engaging capillaries of various inner and outer diameters.

15. A pneumatic concentric nebulizer with an adjustable and replaceable central sample capillary comprising:

a central housing having an open rear end, an open front end, and a bore extending from said rear end to said front end;

a nebulizer tube having a rear gas entrance end, a forward gas expulsion end and an interior surface extending between said gas entrance and gas expulsion ends and defining a channel therebetween, said forward end terminating in an expulsion orifice, said nebulizer tube further including an integral gas conduit depending therefrom which gas conduit is in fluid communication with said channel within said nebulizer tube and attachable to a source of pressurized gas so that pressurized gas can be introduced into said nebulizer tube;

nebulizer tube sealing means proximate to said front end of said housing for removably receiving and sealably engaging said nebulizer tube proximate its gas entrance end so that a gas tight seal is formed between said nebulizer tube and said housing when the apparatus is in use;

a central capillary having a sample intake port, a sample exit port, an outer wall, and an inner wall, said inner wall defining a sample channel that extends from said sample intake port to said sample exit port, said sample intake port being attachable to a source of sample to be pumped into said sample intake port, through said sample channel, and out said exit port to be nebulized;

capillary sealing means proximate to said rear end of said housing, said capillary sealing means being movable between an open position and a sealing position for slidably and removably receiving, and selectively sealably engaging, said capillary such that when said capillary sealing means are in the open position said sample exit port of said capillary may be received through said rear end of said housing and translated linearly forward within said housing toward said gas expulsion end of said nebulizer tube until a desired location for said sample exit port with respect to said gas expulsion orifice has been attained at which point said capillary sealing means can be moved into its sealing position to form a gas tight seal between said housing and said capillary so that when said nebulizer tube and said capillary are both sealably engaged by said housing, and pressurized gas is introduced into said nebulizer tube through said integral gas conduit, the gas is expelled through said gas expulsion orifice of said nebulizer tube at a high enough velocity to nebulize and propel sample being pumped through said sample capillary into the path of the gas generally in the direction of the exiting gas.

16. The invention of claim 15 wherein said forward gas expulsion end of said nubulizer tube is tapered downward toward said orifice to form a substantially cone shaped nozzle.

17. The invention of claim 16 wherein said sample exit port of said capillary is movable between positions beyond said gas expulsion orifice of said nebulizer tube and recessed with respect to said gas expulsion orifice to permit the user to attain various gas back pressures within said nebulizer tube and various nebulization effects.

18. The invention of claim 15 wherein said capillary sealing means is capable of receiving and sealably engaging capillaries of various inner and outer diameters.