Pumpless Metal Atomization And Combustion Using Vacuum Generation And Suitable Material Flow Control

Abstract

A method is provided for combustion of an electropositive metal using a combustion gas. The electropositive metal, in the form of a fluid or powder having particles with a particle size of less than 100 μm, is drawn out of a container by atomizing a carrier gas in a first nozzle, which tapers in relation to the cross-section in the flow direction of the carrier gas. The electropositive metal is drawn out of the container into the first nozzle, atomized out of said nozzle and combusted using the combustion gas.

What is claimed is: 
     
         1 . A method for the combustion of an electropositive metal selected from the group consisting of alkali metals, alkaline earth metals, aluminum, zinc, and alloys or mixtures thereof with a combustion gas, the method comprising:
 providing the electropositive metal in a container in the form of a liquid or powder comprising particles with a particle size of less than 100 μm;   flowing a carrier gas through a first nozzle communicatively coupled to the container via a first passage that meets the first nozzle at a first location along a flow direction of the first nozzle, the first nozzle having a tapered nozzle portion having a tapered cross section and located at least partially upstream of the first location at which the first passage meets the first nozzle;   sucking the electropositive metal from the container and into the first nozzle via the first passage;   wherein the electropositive metal sucked into the first nozzle is atomized in the first nozzle and burned with the combustion gas.   
     
     
         2 . The method of  claim 1 , wherein the first nozzle is a Venturi nozzle including, in order along the flow direction of the carrier gas, the tapered portion, a constant diameter portion, and a widening portion having a widening cross section,
 wherein the first passage from the container opens into the constant diameter portion of the Venturi nozzle.   
     
     
         3 . The method of  claim 1 , wherein the first nozzle comprises a Laval nozzle including the tapered portion that tapers along the flow direction and a diverging portion that diverges along the flow direction. 
     
     
         4 . The method of  claim 3 , wherein the first passage from the container opens into the Laval nozzle at a location of the Laval nozzle having a smallest cross-section. 
     
     
         5 . The method of  claim 1 , wherein the first passage from the container opens into the first nozzle via an outlet opening arranged coaxially within the first nozzle at a location in or downstream of the tapered portion of the first nozzle. 
     
     
         6 . The method of  claim 1 , wherein the first nozzle is being arranged coaxially within the first passage from the container. 
     
     
         7 . The method of  claim 1 , wherein the carrier gas is the combustion gas. 
     
     
         8 . The method of  claim 1 , comprising controlling an amount of atomized electropositive sucked into the first nozzle by controlling a pressure of the carrier gas upstream of the first nozzle along the flow direction of the carrier gas. 
     
     
         9 . A device for burning an electropositive metal selected from the group consisting of alkali metals, alkaline earth metals, aluminum, zinc, and alloys or mixtures thereof with a combustion gas, the device comprising:
 a first nozzle having a tapered portion with a tapered cross section, the first nozzle configured to carry a flow of a carrier gas and to atomize electropositive metal with the carrier gas,   a first feeding device configured to feed carrier gas to the first nozzle,   a container configured to provide the electropositive metal in the form of a liquid or in the form of a powder comprising particles with a particle size of less than 100 μm,   a second feeding device configured to direct the electropositive metal out of the container to the first nozzle, and   a burner configured to burn the electropositive metal with the combustion gas.   
     
     
         10 . The device of  claim 9 , wherein the first nozzle comprises a Venturi nozzle including, in order along the flow direction of the carrier gas, the tapered portion, constant diameter portion, and a widening portion having a widening diameter, wherein the first passage from the container opens into the constant diameter portion of the Venturi nozzle. 
     
     
         11 . The device of  claim 9 , wherein the first nozzle comprises a Laval nozzle including the tapered portion and a diverging portion that diverges along the flow direction. 
     
     
         12 . The device of  claim 11 , wherein the second feeding device opens into the Laval nozzle at a location of the Laval nozzle having a smallest cross-section. 
     
     
         13 . The device of  claim 9 , wherein the second feeding device has an outlet opening arranged coaxially. 
     
     
         14 . The device of  claim 9 , wherein the first feeding device is arranged coaxially within the second feeding device. 
     
     
         15 . The device of  claim 9 , further comprising:
 a third feeding device configured to feed electropositive metal to the container, and   a controlling device configured to control the amount of electropositive metal fed to the container by controlling a pressure of the carrier gas upstream of the first nozzle along the flow direction of the carrier gas.