Methods, Apparatus and Systems for Improving the Operation of Cyclone Boilers

Abstract

A process that uses targeted in-furnace Injection to feed a fluxing agent of the chemical family of compositions containing boron and/or alkali hydrates to either decrease heat transfer on waterwalls of utility furnaces burning solid fuels to improve steam generation, maintain steam temperature, and/or allow a protective layer of slag to form inside the barrels of cyclones on cyclone boilers burning fuels high in calcium so that the boiler can operate at a wider variety of power settings while allowing proper flow and drainage of slag from the cyclone barrels.

1 . A method for controlling slag properties in a cyclone burner of the type having a barrel fed by a tangential supply of air and coal and a layer of slag protecting the inside barrel and flowing out of the barrel, which comprises:
 providing a boron composition in a liquid vehicle;   utilizing computational fluid dynamics to determine the location, droplet size, and dosage amount for injection of a boron composition in a liquid vehicle into a duct for providing air to the cyclone burner, wherein the conditions of introduction of the boron composition and liquid vehicle are determined to assure first contact with the duct wall occur no sooner than after the boron composition has been dried to a fine powder form, without significantly wetting the wall with the liquid vehicle;   injecting the boron composition in a liquid vehicle into the duct to form a dispersion of boron composition as a dry powder in air; and   directing flow of the dry powder of boron composition into the cyclone burner in a tangential flow of air, whereby the fine powder of boron composition uniformly contacts slag in the cyclone burner.   
     
     
         2 . A method according to  claim 1 , wherein the boron composition comprises borate, boric acid, borax or blend of two or more of these. 
     
     
         3 . A method according to  claim 1 , wherein the boron composition material also includes an alkali hydrate. 
     
     
         4 . A method according to  claim 1 , wherein feed of the boron composition is stopped and feed of alkali hydrates is started. 
     
     
         5 . A method according to  claim 1 , wherein the boron composition is introduced into a secondary air duct carrying heated combustion air to the cyclone burner. 
     
     
         6 . A method according to  claim 1 , wherein the boron composition is introduced into the cyclone barrel with tangentially supplied secondary air. 
     
     
         7 . A method for controlling slag properties in a cyclone burner, which comprises:
 utilizing computational fluid dynamics to determine the location, droplet size, and dosage amount of a boron composition in a liquid vehicle necessary for slag modification to assure flow of slag from the cyclone burner while maintaining a protective layer of slag in the burner; and providing precise dosing as to location and amount of a boron composition in a suitable vehicle by controlled feeding through injection ports on each cyclone barrel such that the boron composition lowers the melt point of the slag while making slag thicker, causing a protective layer of slag to form on the cyclone barrel inside wall, but still able to flow to drains.   
     
     
         8 . A method for controlling slag properties in a cyclone burner of the type having a barrel fed by a tangential supply of air and coal and a layer of slag protecting the inside barrel and flowing out of the barrel, which comprises:
 providing a boron composition in a liquid vehicle;   injecting the boron composition in a liquid vehicle into a duct carrying hot air to the cyclone burner to dray and transport the boron composition as a dry powder without significantly wetting the wall with the liquid vehicle; and   directing a flow of the dry powder of boron composition into the cyclone burner in a tangential flow of air, whereby the fine powder of boron composition uniformly contacts slag in the cyclone burner.   
     
     
         9 . A method according to  claim 8 , wherein the boron composition is introduced into the cyclone barrel with tangentially supplied secondary air. 
     
     
         10 . A method according to  claim 8 , wherein the boron composition comprises borate, boric acid, borax or blend of two or more of these. 
     
     
         11 . A method according to  claim 8 , wherein the boron composition material also includes an alkali hydrate. 
     
     
         12 . A method according to  claim 8 , wherein feed of the boron composition is stopped and feed of alkali hydrates is started. 
     
     
         13 . A method according to  claim 8 , wherein the boron composition is introduced into a secondary air duct carrying heated combustion air to the cyclone burner. 
     
     
         14 . A method according to  claim 8 , wherein computational fluid dynamics is utilized to determine the location, droplet size, and dosage amount for injection of a boron composition in a liquid vehicle into a duct for providing air to the cyclone burner, wherein the conditions of introduction of the boron composition and liquid vehicle are determined to assure first contact with the duct wall occur no sooner than after the boron composition has been dried to a fine powder form, without significantly wetting the wall with the liquid vehicle. 
     
     
         15 . A system and/or apparatus comprising control means, sensors and feed devices for effecting the process of  claim 1 .