Refractory insert members, refractory block assembly including same and reformer flue gas tunnel assembly including same

A refractory tunnel assembly for a steam reformer furnace, the 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 the mechanical mating members of the base components, wherein at least a portion of the plurality of wall blocks further comprise at least one through-hole having openings formed in opposed side surfaces thereof;
• 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;
• and
• one or more refractory insert members that reside within one or more of the though-holes in said wall blocks;
• wherein said base components are arranged to extend in a horizontal arrangement direction defining a width of the tunnel assembly and a longitudinal arrangement direction defining a length of the tunnel assembly;
• wherein the wall blocks are stacked upon and mechanically interconnected to the base components via the corresponding mechanical mating members in a vertical arrangement direction and along the longitudinal arrangement direction, and are stacked upon one and mechanically interconnected to another via the corresponding mechanical mating members, without the use of mortar, in both the vertical and longitudinal arrangement directions, to define two parallel tunnel walls, spaced a distance apart from one another in the horizontal arrangement direction, wherein the tunnel walls extend upwardly from the base components in the vertical arrangement direction and along the length of the tunnel assembly on the base components;
• and
• wherein the plurality of lid components are stacked upon and mechanically interconnected to the wall blocks via the mechanical mating members, without the use of mortar, in the vertical arrangement direction and along the longitudinal arrangement direction, so that the lids extend along the longitudinal arrangement direction and the horizontal arrangement direction in order to cover the distance between the tunnel walls along at least a portion of the length of the tunnel assembly.