Concentricity for long concentric nebulizers

Abstract

A method for stabilizing and centrally positioning an inner capillary in a concentric nebulizer comprises supporting the inner capillary near the tip of the nebulizer by contacting the nebulizer body against the inner capillary or by interposing a support between the nebulizer body and the inner capillary near the tip. An embodiment of a nebulizing device having stabilized central positioning of its inner capillary is disclosed which comprises an outer capillary with a linear bore and a gas/liquid orifice in a distal tip, a central capillary disposed within the linear bore, and a support sufficiently proximate the orifice to maintain the central capillary substantially centered within the outer capillary adjacent to the orifice. An open volume within the outer capillary between the orifice and the support is dimensioned to enable gas flow to spread substantially evenly around the central capillary.

1 . A method for maintaining the centricity of a central capillary of a concentric nebulizer, comprising the steps of:
 providing a concentric nebulizer outer capillary, which outer capillary comprises a length, external and internal diameters, a bore, and an inner wall, said outer capillary terminating at a tip and having an orifice in said tip for gas and/or liquid,   providing a first central capillary having external and internal diameters disposed within the outer capillary; and   providing a support of the first central capillary sufficiently near the orifice to maintain the first central capillary centered within the outer capillary and with respect to a center of the orifice.   
   
   
       2 . The method of  claim 1 , further comprising
 providing a volume intermediate the support of the central capillary and the orifice; and   providing at least one passage proximate the first central capillary for allowing nebulizer gas to flow into the volume.   
   
   
       3 . The method of  claim 2 , wherein the volume is large enough to allow the gas flow to spread reasonably evenly around the first central capillary before exiting the orifice. 
   
   
       4 . The method of  claim 1 , further comprising
 inserting the support about the first central capillary and within the outer capillary, said support having a length and comprising a hub portion that has an internal diameter approximately equal to the external diameter of the first central capillary, and said support further comprising, in cross-sectional aspect, a plurality of fins integral with and extending radially from the hub region for contacting an internal wall of the outer capillary, wherein each fin has a base where the fin integrally connects with the hub portion and a tip where the fin contacts the inner wall of the outer capillary along a length of a support region.   
   
   
       5 . The method of  claim 4 , further comprising
 providing fins having a cross-sectional aspect tapering from relatively greater thickness at their base to relatively lesser thickness at their tip.   
   
   
       6 . The method of  claim 1 , further comprising
 providing disposed inside the first central capillary a second central capillary,   terminating the first central capillary proximate the support, and   extending the second central capillary beyond the termination of the first central capillary.   
   
   
       7 . The method of  claim 6 , further comprising
 providing a third central capillary disposed outside the first central capillary,   terminating the third central capillary on a side of the support opposite the orifice, and   extending the first central capillary beyond the termination of the third central capillary.   
   
   
       8 . The method of  claim 1 , further comprising
 forming or molding an inner wall of the outer capillary such that the formed or molded inner wall contacts the first central capillary in a support region proximate to the orifice,   wherein the step of providing a support includes centrally supporting the first central capillary by contact with the formed or molded outer capillary inner wall to maintain the first central capillary centered within the outer capillary adjacent to the orifice.   
   
   
       9 . The method of  claim 8 , further comprising
 forming or molding the inner wall of the outer capillary such that an open volume shaped in cross-sectional aspect as an equilateral polygon is formed within, and   disposing the first central capillary, in cross-sectional aspect, as an incircle of said polygon.   
   
   
       10 . The method of  claim 8 , further comprising
 forming or molding the inner wall into, in cross-sectional aspect, a plurality of ridges projecting from the inner wall of the outer capillary for supportably contacting the first central capillary, wherein each of the ridges has a base where the ridge integrally connects with the inner wall of the outer capillary and a tip for contacting the outer surface of the first central capillary.   
   
   
       11 . The method of  claim 10  wherein each ridge runs the length of the support region. 
   
   
       12 . The method of  claim 10 , further comprising
 forming the inner wall as a plurality of symmetrically disposed ridges in the support region.   
   
   
       13 . The method of  claim 1 , further comprising
 providing the bore in the outer capillary dimensioned to receive the first central capillary and to support the first central capillary along a majority of its length centered in said outer capillary, and   providing a notch or notches along the outer surface of the first central capillary and in fluid communication with the gas input to allow gas to flow from a gas input to the gas/liquid orifice through the notch or notches along said first central capillary with minimal turbulence.   
   
   
       14 . The method of  claim 13 , further comprising
 providing at least one notch cut from the outer surface of the first central capillary such that a cross-sectional profile of the first central capillary comprises a circle from which a chord segment is removed.   
   
   
       15 . The method of  claim 1 , wherein the step of providing a first central capillary comprises
 providing a multilumen central capillary having a central lumen for conveying a liquid flow and having at least one non-central lumen for conveying a gas, and   wherein the step of providing an outer capillary comprises providing the bore in the outer capillary dimensioned to receive the multilumen central capillary and to support the multilumen central capillary by contact along a majority of its length.   
   
   
       16 . The method of  claim 15 , further comprising
 progressively diminishing a radius of the first central capillary in a region proximate the orifice such that the first central capillary comprises only the central lumen adjacent the orifice.   
   
   
       17 . The method of  claim 1 , further comprising
 providing a first central capillary having a wall with a thickness, wherein the thickness of the wall tapers without changing a diameter of a central lumen contained within the first central capillary along a distance from the support to a point adjacent the orifice, such that at the termination of the first central capillary the external diameter of the central capillary is substantially equal to the diameter of the central lumen.   
   
   
       18 . The method of  claim 1 , further comprising
 maintaining smooth gas flow in the nebulizer by providing passages around, beside or through said support for allowing the gas to flow past or through the support with minimal turbulence and by providing an open volume near the gas orifice, which volume is large enough to allow the gas flow to spread substantially evenly around the central capillary.   
   
   
       19 . A nebulizing device comprising
 a nebulizer body with gas and liquid inputs,   an outer capillary having external and internal diameters, a length, a wall, an inner wall surface defining a bore and a distal tip,   a substantially linear, cylindrical, first central capillary disposed within the bore, said first central capillary having an external diameter and an outer surface;   at least one lumen within the first central capillary;   a gas/liquid orifice in the tip of the outer capillary;   a support positioned in a support region sufficiently proximate the orifice to maintain the first central capillary substantially centered within the outer capillary adjacent to the orifice; and   an open volume within the outer capillary intermediate the orifice and the support dimensioned to allow the gas flow to spread substantially evenly around the first central capillary.   
   
   
       20 . The nebulizing device of  claim 19 , further comprising
 passages around, beside or through said support for allowing gas to flow past or through the support region with minimal turbulence.   
   
   
       21 . The nebulizing device of  claim 19 , wherein
 the support comprises a hub portion having an internal diameter approximately equal to the external diameter of the first central capillary, and, in cross-sectional aspect, a plurality of fins integral with and extending radially from the hub region to contact the inner wall surface of the outer capillary, the support being inserted around the first central capillary and within the outer capillary;   wherein each fin has a base where the fin integrally connects with the hub portion and a tip where the fin contacts the inner wall surface of the outer capillary along a length of the support region.   
   
   
       22 . The nebulizing device of  claim 21 , wherein each fin tapers in thickness from relatively greater thickness at its base to relatively lesser thickness at its tip. 
   
   
       23 . The nebulizing device of  claim 19 , further comprising
 a second central capillary disposed within the first central capillary, the first central capillary being supported by and terminating proximate the support, and the second central capillary extending beyond the termination of the first central capillary substantially through the volume and terminating adjacent the orifice.   
   
   
       24 . The nebulizing device of  claim 23 , further comprising
 a third central capillary disposed outside the first central capillary and terminating on a side of the support opposite the orifice and being not directly supported by the support.   
   
   
       25 . The nebulizing device of  claim 19 , wherein
 the outer capillary has an inner wall formed or molded to contact and centrally support the first central capillary along the length of a support region,   wherein the support maintains the first central capillary centered within the outer capillary adjacent to the orifice.   
   
   
       26 . The nebulizing device of  claim 25 , wherein
 the inner wall in cross-section is formed as an equilateral polygon, and   inside the polygon, the external diameter of the first central capillary, in cross-section, forms an incircle.   
   
   
       27 . The nebulizing device of  claim 25 , wherein
 the support comprises, in cross-section, a plurality of ridges projecting integrally from the inner wall surface of the outer capillary to contact the first central capillary, wherein at least one ridge of the plurality of ridges has a base wherein the ridge is integrally connected with the inner wall surface of the outer capillary and a tip where the ridge contacts the outer surface of the first central capillary.   
   
   
       28 . The nebulizing device of  claim 27 , wherein each ridge runs the length of the support region. 
   
   
       29 . The nebulizing device of  claim 27 , wherein the plurality of ridges are symmetrically disposed in the support region. 
   
   
       30 . The nebulizing device of  claim 19 , wherein
 the bore in the outer capillary is dimensioned to receive said first central capillary and to support the first central capillary by contact along a majority of its length, wherein the first central capillary is maintained centered within the outer capillary adjacent to the orifice;   at least one notch is cut along the outer surface of the first central capillary and are in fluid communication with the gas input and the open volume, such that gas can flow from the gas input to the open volume and thereby to the gas/liquid orifice through the at least one notch along said first central capillary with minimal turbulence; and   the support positioned about the first central capillary is continued sufficiently close to the orifice to maintain the first central capillary centered within the outer capillary proximate the center of the orifice.   
   
   
       31 . The nebulizing device of  claim 30 , wherein the at least one notch is cut from the outer surface of the first central capillary such that a cross-sectional profile of the first central capillary comprises a circle from which a chord segment is removed. 
   
   
       32 . The nebulizing device of  claim 19 , wherein
 the first central capillary comprises a multilumen central capillary having a central lumen for conveying a liquid flow and at least one non-central lumen for conveying a gas flow; and   the bore in said outer capillary is dimensioned to receive and to support said multilumen capillary by contact along a majority of its length.   
   
   
       33 . The nebulizing device of  claim 32 , wherein
 a radius of the multilumen capillary diminishes toward the orifice such that the multilumen capillary comprises only the central lumen proximate and after the end of the support region.   
   
   
       34 . The nebulizing device of  claim 19 , wherein
 the first central capillary has a wall having a thickness, wherein the thickness of the wall tapers without changing a diameter of the lumen contained within the first central capillary along a distance from the support to a point adjacent the orifice, such that at the termination of the first central capillary the external diameter of the first central capillary is substantially equal to the diameter of the lumen.   
   
   
       35 . The nebulizing device of  claim 19 , wherein
 the support is located entirely in a half of the outer capillary that contains the orifice.