Slot-port system

Abstract

A multiple level combustion air system for a chemical recovery boiler incorporates a single level of secondary air ports, with the air ports having an aspect ratio greater than 12. A second embodiment incorporates one or more tertiary levels of combustion air ports with the ports having an aspect ratio greater than 12. Further embodiments incorporate a combination high aspect ration combustion air port and auxiliary fuel burner opening; damper and cleaner means; and the injection of gases through one or more of the combustion air ports.

1 . A combustion air system for a recovery boiler having at least a primary air level, a secondary air level, and a tertiary air level, in which the secondary air level consists of a single level of combustion air ports, located at an elevation above the primary ports and below the liquor spray level, wherein at least one of the said combustion air ports have an aspect ratio greater than 12, with the aspect ratio defined as the relationship H2/A, where H equals the height of the opening, and A equals the area of the opening.  
   
   
       2 . The combustion air system of  claim 1 , in which one or more of the secondary and/or tertiary combustion air ports also incorporate an opening for an auxiliary fuel burner, in which case the aspect ratio is based on the area of the port minus the area required for the burner.  
   
   
       3 . The combustion air system of  claim 1 , in which the height of the combustion air ports is defined by the extents of the membrane, refractory or other material between the boiler tubes, or by the location where bent boiler tubes resume their normal location in the tube wall, and the area is the area between the tubes to the limits of the height of the port, the area including the projected area of any castings, sleeves, dampers, restrictor plates, liners, baffle plates, dividers, diverters, cleaners, or refractory, except such refractory that may define the height of the port.  
   
   
       4 . The combustion air system of  claim 1 , in which a damper means is fitted to cover variably all or part of one or more of the secondary and/or tertiary combustion air port openings.  
   
   
       5 . The combustion air system of  claim 1 , in which an automatic cleaner means is fitted to clean one or more of the secondary and/or tertiary combustion port openings.  
   
   
       6 . The combustion air system of  claim 1 , in which non-condensable gasses or other gasses are injected into the boiler through one or more of the secondary and/or tertiary combustion air port openings.  
   
   
       7 . A combustion air system for a recovery boiler having at least a primary air level, a secondary air level, and a tertiary air level, in which the secondary air level consists of a single level of combustion air ports, located at an elevation above the primary ports and below the liquor spray level, and at least one tertiary air level located at or above the liquor spray level, wherein at least one of the said combustion air ports have an aspect ratio greater than 12, with the aspect ratio defined as the relationship H2/A, where H equals the height of the opening, and A equals the area of the opening.  
   
   
       8 . The combustion air system of  claim 7 , in which one or more of the secondary and/or tertiary combustion air ports also incorporate an opening for an auxiliary fuel burner, in which case the aspect ratio is based on the area of the port minus the area required for the burner.  
   
   
       9 . The combustion air system of  claim 7 , in which the height of the combustion air ports is defined by the extents of the membrane, refractory or other material between the boiler tubes, or by the location where bent-boiler tubes resume their normal location in the tube wall, and the area is the area between the tubes to the limits of the height of the port, the area including the projected area of any castings, sleeves, dampers, restrictor plates, liners, baffle plates, dividers, diverters, cleaners, or refractory, except such refractory that may define the height of the port.  
   
   
       10 . The combustion air system of  claim 7 , in which a damper means is fitted to cover variably all or part of one or more of the secondary and/or tertiary combustion air port openings.  
   
   
       11 . The combustion air system of  claim 7 , in which an automatic cleaner means is fitted to clean one or more of the secondary and/or tertiary combustion port openings.  
   
   
       12 . The combustion air system of  claim 7 , in which non-condensable gasses or other gasses are injected into the boiler through one or more of the secondary and/or tertiary combustion air port openings.  
   
   
       13 . A combustion air system for a recovery boiler having at least a primary air level, a secondary air level, and at least one tertiary air level located at or above the liquor spray level, wherein at least one of the tertiary combustion air ports have an aspect ratio greater than 12, with the aspect ratio defined as the relationship H2/A, where H equals the height of the opening, and A equals the area of the opening.  
   
   
       14 . The combustion air system of  claim 13 , in which one or more of the secondary and/or tertiary combustion air ports also incorporate an opening for an auxiliary fuel burner, in which case the aspect ratio is based on the area of the port minus the area required for the burner.  
   
   
       15 . The combustion air system of  claim 13 , in which the height of the combustion air ports is defined by the extents of the membrane, refractory or other material between the boiler tubes, or by the location where bent boiler tubes resume their normal location in the tube wall, and the area is the area between the tubes to the limits of the height of the port, the area including the projected area of any castings, sleeves, dampers, restrictor plates, liners, baffle plates, dividers, diverters, cleaners, or refractory, except such refractory that may define the height of the port.  
   
   
       16 . The combustion air system of  claim 13 , in which a damper means is fitted to cover variably all or part of one or more of the secondary and/or tertiary combustion air port openings.  
   
   
       17 . The combustion air system of  claim 13 , in which an automatic cleaner means is fitted to clean one or more of the secondary and/or tertiary combustion port openings.  
   
   
       18 . The combustion air system of  claim 13 , in which non-condensable gasses or other gasses are injected into the boiler through one or more of the secondary and/or tertiary combustion air port openings.