Humidifier

Abstract

A humidifier includes a heating element including a porous structure of electrically resistive and thermally conductive material configured to substantially vaporise liquid that is passed through the porous structure. The porous structure has a liquid inlet and a vapour outlet. The humidifier further includes an outer housing surrounding at least a portion of the porous structure for containing the liquid and vapour within the porous structure. The porous structure includes a first electrical connector and a second electrical connector, the first and second connectors being configured for receiving electrical power and applying a voltage across the porous structure to generate heat.

1 . A humidifier, comprising:
 a heating element including a porous structure of electrically resistive and thermally conductive material configured to substantially vaporise liquid that is passed through the porous structure, the porous structure having a liquid inlet and a vapour outlet;   an outer housing surrounding at least a portion of the porous structure for containing the liquid and vapour within the porous structure; and   wherein the porous structure includes a first electrical connector and a second electrical connector, the first and second connectors being configured for receiving electrical power and applying a voltage across the porous structure to generate heat.   
     
     
         2 . The humidifier according to  claim 1 , wherein the first electrical connector is located at or near the liquid inlet and the second electrical connector is located at or near the vapour outlet. 
     
     
         3 . The humidifier according to  claim 1 , further comprising a connector fitting configured to deliver liquid from a supply of liquid to the liquid inlet. 
     
     
         4 . The humidifier according to  claim 3 , wherein the connector fitting comprises a connection spigot, and the humidifier further comprises a sealing tube configured to form a sealed connection between the connection spigot and the outer housing. 
     
     
         5 . The humidifier according to  claim 3 , wherein the connector fitting comprises a liquid inlet spigot configured to receive liquid from the supply of liquid, and wherein the humidifier further comprises a liquid supply tube connected to the liquid inlet spigot. 
     
     
         6 . The humidifier according to  claim 1 , wherein the first electrical connector and/or the second electrical connector is a crimp connector. 
     
     
         7 . The humidifier according to  claim 1 , wherein the porous structure and the outer housing are each elongate, and the vapour outlet of the porous structure is configured to be exposed to a flow of breathable gas to be humidified through an open end of the outer housing. 
     
     
         8 . The humidifier according to  claim 7 , wherein the vapour outlet of the porous structure extends beyond the outer housing. 
     
     
         9 . The humidifier according to  claim 1 , wherein the porous structure has a cylindrical shape or a tapered shape. 
     
     
         10 . The humidifier according to  claim 1 , wherein the porous structure is formed of an open pore metal foam. 
     
     
         11 . The humidifier according to  claim 10 , wherein the metal comprises a chromium alloy, the chromium alloy comprising MCrAlX, where M is one or more of Nickel (Ni), Cobalt (Co) or Iron (Fe) contributing at least 50% by weight, Chromium (Cr) contributing between 8% and 35% by weight, Aluminium (Al) contributing greater than 0% but less than 8% by weight, and X contributing less than 25% by weight, with X including zero or more other elements, including to Molybdenum (Mo), Rhenium (Re), Ruthenium (Ru), Titanium (Ti), Tantalum (Ta), Vanadium (V), Tungsten (W), Niobium (Nb), Zirconium (Zr), Boron (B), Carbon (C), Silicon (Si), Yttrium (Y) and Hafnium (Hf). 
     
     
         12 . The humidifier according to  claim 10 , wherein the metal foam is formed by pyrolysis and/or metallisation of a polymer foam such as an open cell polyurethane foam. 
     
     
         13 . The humidifier according to  claim 1 , wherein the porous structure comprises a body of fibres. 
     
     
         14 . The humidifier according to  claim 13 , wherein the body of fibres is bundled in a form of tow-, twist-, knit-, braid-, felt-, woven fabric- or tape-structures. 
     
     
         15 . The humidifier according to  claim 13 , wherein the body of fibres comprises carbon fibres. 
     
     
         16 . The humidifier according to  claim 15 , wherein the carbon fibres have precursors of Poly Acyrlic Nitrile, rayon and/or pitch. 
     
     
         17 . The humidifier according to  claim 1 , wherein the porous structure is formed of ceramic material such as silicon carbide, titanium nitride or pyrolytic carbon. 
     
     
         18 . The humidifier according to  claim 1 , wherein the porous structure has a substantially uniform porosity or has a porosity that varies along its length and/or diameter. 
     
     
         19 . The humidifier according to  claim 1 , wherein the outer housing is formed of electrically and thermally insulating material. 
     
     
         20 . The humidifier according to  claim 19 , wherein the outer housing is formed of alumina, fused quartz, or a polymer such as heat shrink or silicone rubber.