Cast iron or aluminum sectional boiler

Abstract

A cast iron or aluminum sectional boiler, in particular a condensing boiler, having generally annular sections, one front section, one cover-like rear section and at least one center section being provided which form a furnace chamber having generally surrounding heating gas passages, and their annular water compartments are connected to one another via hubs. The sections have one lower return connection and one upper feed connection as well as at least two anchor rods for holding the section block together. The cast iron or aluminum sectional boiler is optimized with respect to compactness and robustness. Annular gaps are in each case provided as heating gas passages between two adjacent sections, each of which, starting from the furnace chamber, runs approximately radially outwards and leads into an exhaust gas collection chamber on the outside of the sections.

1 - 13 . (canceled) 
     
     
         14 . A cast iron or aluminum sectional condensing boiler, comprising:
 annular sections, including a front section, a cover-like rear section and at least one center section, the sections forming a furnace chamber having surrounding heating gas passages and annular water compartments connected to one another via hubs, the sections having one lower return connection and one upper feed connection and at least two anchor rods for holding the sections together;   wherein annular gaps are provided between each of two adjacent ones of the sections as heating gas passages which run approximately radially outwards starting from the furnace chamber and discharge into an exhaust gas collection chamber on an outside of the sections.   
     
     
         15 . The sectional boiler as recited in  claim 14 , wherein each of two adjacent ones of the sections has a matching geometry for forming an annular gap. 
     
     
         16 . The sectional boiler as recited in  claim 14 , wherein an annular gap runs radially at a right angle to a central axis of the furnace chamber and in a straight line to the outside. 
     
     
         17 . The sectional boiler as recited in  claim 14 , wherein an annular gap runs to the outside radially curved. 
     
     
         18 . The sectional boiler as recited in  claim 14 , wherein an annular gap runs in a straight line to the outside, tilted toward a central axis of the furnace chamber. 
     
     
         19 . The sectional boiler as recited in  claim 14  wherein an annular gap runs radially to the outside in a wave-like fashion. 
     
     
         20 . The sectional boiler as recited in  claim 14 , wherein at least one of a width and an open cross section of an annular gap diminishes from the furnace chamber to the opening on the outside of the sections. 
     
     
         21 . The sectional boiler as recited in  claim 14 , wherein surfaces of the sections are contacted by a heating gas gap are provided with a corrosion-resistant coating. 
     
     
         22 . The sectional boiler as recited in  claim 14 , wherein the exhaust gas collection chamber on the outside of the sections, into which the annular gaps discharge, extends in a form of a hollow cylinder around outer jacket surfaces of the sections and is limited to the outside by a jacket which is sealingly accommodated between annular webs projecting radially outwards on the outside of the front and the rear sections. 
     
     
         23 . The sectional boiler as recited in  claim 14 , wherein the at least two anchor rods are situated within the hubs for holding the sections together. 
     
     
         24 . The sectional boiler as recited in  claim 14 , wherein a feed pipe for at least one of return water and a withdrawal pipe for feed water situated within the hubs is used for holding the sections together. 
     
     
         25 . The sectional boiler as recited in  claim 24 , wherein an upper one of the hubs and a lower one of the hubs are alternately closed for providing a forced flow between the return and feed connection, and wherein a closure arrangement is attached to at least one of the anchor rods, feed pipe, and the withdrawal pipe. 
     
     
         26 . The sectional boiler as recited in  claim 14 , wherein at least two centering points or surfaces representing unfinished casting dimensions and tolerances are provided on each of the sections for maintaining an exact gap size between two adjacent ones of the sections and the centering points or surfaces determine mechanical machining of sealing or contact surfaces on the hubs.