Reformer flue gas tunnel and refractory components therefor

A refractory tunnel assembly for a steam reformer furnace, said tunnel assembly comprising:

• a plurality of hollow base components, each said base component comprising a plurality of corresponding mechanical mating members;
• a plurality of hollow wall blocks, each said wall block comprising a plurality of corresponding mechanical mating members that further correspond to said mechanical mating members of said base components;
• and
• a plurality of hollow lid components, each said lid component comprising a plurality of mechanical mating members that further correspond to said mechanical mating members of said base components and said wall blocks;
• wherein said base components are arranged to extend in a horizontal arrangement direction defining a width of said tunnel assembly and a longitudinal arrangement direction defining a length of the tunnel assembly;
• wherein said wall blocks are stacked upon and mechanically interconnected to said base components via said corresponding mechanical mating members, without the use of mortar, in a vertical arrangement direction and along said longitudinal arrangement direction, and are stacked upon one and mechanically interconnected to another via said corresponding mechanical mating members, without the use of mortar, in both said vertical and longitudinal arrangement directions, to define two parallel tunnel walls, spaced a distance apart from one another in the horizontal arrangement direction, wherein said tunnel walls extend upwardly from said base components in said vertical arrangement direction and along the length of said tunnel assembly on said base components;
• and
• wherein said plurality of lid components are stacked upon and mechanically interconnected to said wall blocks via said mechanical mating members, without the use of mortar, in the vertical arrangement direction and along said longitudinal arrangement direction, so that said lids extend along the longitudinal arrangement direction and the horizontal arrangement direction in order to cover said distance between said tunnel walls along at least a portion of said length of said tunnel assembly;
• and
• wherein said wall blocks comprises a refractory block comprising:
• a hollow main body portion having an outer peripheral surface defining a first end, an opposed second end, an upper surface, an opposed lower surface, a first side and an opposed second side, wherein the upper surface and the opposed lower surface define a cavity through the main body portion;
• at least one first mechanical mating member defining a protruded portion extending from a portion of said upper surface of said main body portion and enclosing the cavity;
• at least one second corresponding mechanical mating member defining an opening corresponding to said protruded portion and formed in a portion of said lower surface of said main body portion;
• at least one third mechanical mating member defining a tab provided in a portion of said first end or said opposed second end of said main body portion, or said first side, or said opposed second side of said main body portion;
• and
• at least one fourth mechanical mating member comprising a groove corresponding to said tab, said groove being formed in said first end, or in said second end, or in said first side, or in said opposed second side of said main body portion being opposite respective said end or side of said main body portion provided with said tab.