Steam Generator

Abstract

A steam generator which may be mobile or stationary, which includes a fire box the outlet of which is connected to a cyclone section; the outlet of the cyclone section opens into a water tube steam boiler, with the connection between the cyclone section and the water tube steam boiler being such that the cyclone section substantially isolates the water tube steam boiler from the radiant heat of a fire in the fire box; a structural shell contains the fire box, cyclone section and water tube steam boiler and is arranged to both provide a containment vessel if the contained components fail in use and also to bear any of the structural loads applied to the generator in use.

1 . A steam generator which includes:
 a firebox in which fuel is burnt to produce heat and gases that are expelled through a firebox outlet;   a cyclone section connected to the firebox wherein the cyclone section has a cyclone section inlet and a cyclone section outlet, and wherein the firebox outlet communicates with the cyclone section inlet so that the gases from the firebox outlet pass into the cyclone section;   a water tube steam boiler connected to the cyclone section outlet of the cyclone section such that the gases from the cyclone section pass into the water tube steam boiler wherein the cyclone section substantially isolates the water tube steam boiler from the radiant heat of the fire in the firebox in use;   a structural shell adapted to contain the firebox, the cyclone section and the water tube steam boiler, said shell being constructed to provide a containment vessel for the firebox, the cyclone section and the water tube boiler in use;   wherein said structural shell further bears structural loads applied to the steam generator in use, such that the firebox, the cyclone section and the water tube steam boiler are isolated from the structural loads applied to the steam generator in use.   
     
     
         2 . The generator as claimed in  claim 1 , wherein the cyclone section consists of a single cyclone. 
     
     
         3 . The generator as claimed in  claim 1 , wherein the cyclone section consists of at least two cyclones, with cyclones arranged either in series or in parallel. 
     
     
         4 . The generator as claimed in  claim 1 , wherein the water tube steam boiler is a mono tube boiler. 
     
     
         5 . The generator as claimed in  claim 1 , wherein the water tube steam boiler is a multi-tube boiler. 
     
     
         6 . The generator as claimed in  claim 1 , wherein the water tube steam boiler is a forced circulation boiler. 
     
     
         7 . The generator as claimed in  claim 1 , wherein the water tube steam boiler is designed to permit the gases to flow therethrough in use in an axial flow direction, substantially parallel to the length of said boiler. 
     
     
         8 . The generator as claimed in  claim 1 , wherein the water tube steam boiler is designed to permit the gases to flow therethrough in use in an axial direction, substantially parallel to the length of the boiler and also in a plurality of radial directions, substantially perpendicular to the axial direction, at a plurality of positions along the length of the boiler. 
     
     
         9 . The generator as claimed in  claim 1 , wherein the water tube steam boiler includes at least one spirally wound boiler tube. 
     
     
         10 . The steam generator as claimed in  claim 1 , wherein the firebox is a dry firebox. 
     
     
         11 . The steam generator as claimed in  claim 1 , wherein the firebox, the cyclone section, and the water tube steam boiler are positioned adjacent each other along a horizontal axis. 
     
     
         12 . The steam generator as claimed in  claim 1 , wherein the firebox, the cyclone section and the water tube steam boiler are positioned adjacent each other along a vertical axis. 
     
     
         13 . The steam generator as claimed in  claim 1 , further including a steam separator connected to a steam outlet from said water tube steam boiler. 
     
     
         14 . The steam generator as claimed in  claim 13 , wherein water is drained from said steam separator and is recirculated to the water tube steam boiler. 
     
     
         15 . The steam generator as claimed in  claim 13 , further including a steam superheater which is connected to the steam separator so as to receive steam from the steam separator in use. 
     
     
         16 . The steam generator as claimed in  claim 1 , further including a smoke box formed by f said structural shell, the smoke box being arranged such that in use, the gases which have passed through the boiler pass into the smoke box, the smoke box being provided with a flue for venting said gases, and with a draft generating arrangement to create a draft through the flue in use. 
     
     
         17 . The steam generator as claimed in  claim 1 , wherein the the cyclone section inlet for each cyclone section includes a solid central portion surrounded by a plurality of peripheral vanes, such that the gases passing from the firebox outlet to the cyclone section in use pass through said vanes, each of said vanes being angled at an acute angle to the solid central portion. 
     
     
         18 . The steam generator as claimed in  claim 17 , wherein each of said vanes is angled to the solid central portion at an angle in the range 5° - 80°. 
     
     
         19 . The steam generator as claimed in  claim 18 , wherein each of said vanes is angled to the solid central portion at an angle in the range 20° - 30°. 
     
     
         20 . The steam generator as claimed in  claim 17 , wherein the angle of each of said vanes is adjustable. 
     
     
         21 . (canceled)