Gases mixing apparatus

Abstract

A gas and air mixing device receives a pressurised supply of a gas, drawing an air supply from the ambient environment and outputs a pressurised combined mixture of air and said gas. The device includes a turbine with a gases inlet and a gases outlet and a pump with an air inlet and an air outlet. A combined gases outlet receives gases from the gases outlet of the turbine and air from the air outlet of the pump. The combined gases outlet ouputs a combined flow of the gases. The turbine is configured to drive the pump.

1 . A gas and air mixing device for receiving a pressurised supply of a gas, drawing an air supply from the ambient environment and outputting a pressurised combined mixture of air and said gas comprising: 
 a turbine having a gases inlet and a gases outlet,    a pump having an air inlet and an air outlet, and    a combined gases outlet receiving gases from said gases outlet of said turbine and air from said air outlet of said pump and outputting a combined flow;    said turbine being configured to drive said pump.    
     
     
         2 . A mixing device as claimed in  claim 1  wherein, 
 said turbine comprises: 
 a first chamber having an oxygen inlet and an oxygen outlet and a turbine in said first chamber receiving oxygen from said oxygen inlet;  
 
 said pump comprises: 
 a second chamber having an air inlet and an air outlet, and  
 an impeller in said second chamber receiving air from said air inlet; and  
 a drive train connects between said turbine and said impeller.  
 
 
     
     
         3 . A mixing device as claimed in  claim 2  wherein the oxygen inlet is configured for connection with an oxygen wall outlet or a compressed oxygen bottle outlet.  
     
     
         4 . A mixing device as claimed in  claim 2  wherein said air inlet includes an adjustable air flow damper.  
     
     
         5 . A mixing device as claimed in  claim 4  wherein said adjustable air flow damper includes a calibration corresponding with the proportion of air or oxygen in the mixed flow for at least one set oxygen inlet pressure.  
     
     
         6 . A mixing device as claimed in  claim 2  wherein said first chamber and said second chamber are back to back, said turbine and said impeller are co-axial, and said drive train comprises a shaft, and both said turbine and said impeller are connected to said shaft.  
     
     
         7 . A mixing device as claimed in  claim 6  wherein said shaft is an integrally formed extension from the centre of said impeller, extending through a dividing wall between said first chamber and said second chamber, into said first chamber, and said turbine is mounted on said extension.  
     
     
         8 . A mixing device as claimed in  claim 7  wherein said first chamber is formed by a covet member fitted to said dividing wall enclosing said turbine.  
     
     
         9 . A mixing device as claimed in  claim 8  wherein said second chamber is formed from a cover fitted to said dividing wall and enclosing said impeller, said second cover including an air inlet at the centre of its main face.  
     
     
         10 . A mixing device as claimed in  claim 1  wherein said device is arranged axially, said turbine comprising: 
 an axial turbine having a gases inlet and gases outlet,  
 said pump comprising an axial pump receiving gases from said gases outlet of said turbine and air from a separate air inlet, and  
 said combined gases outlet receiving gases from said pump and outputting a combined flow;  
 with said turbine and pump being arranged in axial alignment and said turbine being configured to drive said pump.  
 
     
     
         11 . A mixing device as claimed in  claim 10  wherein said device includes a housing with a first section and a second section, said first section having said oxygen inlet and said oxygen outlet and housing a rotor of said turbine; and 
 said second section having an air inlet, an oxygen inlet and said pump gases outlet, and  
 housing an impeller;  
 a drive train connecting between said rotor and said impeller.  
 
     
     
         12 . A mixing device as claimed in  claim 10  wherein the oxygen inlet is configured for connection with an oxygen wall outlet or a compressed oxygen bottle outlet.  
     
     
         13 . A mixing device as claimed in  claim 10  wherein said air inlet includes an adjustable air flow damper.  
     
     
         14 . A mixing device as claimed in  claim 13  wherein said adjustable air flow damper includes a calibration corresponding with the proportion of air or oxygen in the mixed flow for at least one set oxygen inlet pressure.  
     
     
         15 . A mixing device as claimed in  claim 11  wherein said first section and said second section are coaxial and concentric over at least part of their length, said turbine rotor and said impeller are co-axial, and said drive train comprises a shaft, and both said turbine and said impeller are connected to said shaft.  
     
     
         16 . A mixing device as claimed in  claim 15  wherein said shaft is an integrally formed extension from the centre of said impeller, mounted concentrically within said first and second sections.  
     
     
         17 . A mixing device as claimed in  claim 16  wherein said first and second sections are connected in a manner which allows unrestricted flow of ambient air into said second section through an annular opening between overlapping portions of said first section and said second section.