A channel type induction furnace with a furnace floor that is inclined downwards from an operative rear of the furnace hearth towards an opposing operative front of the hearth, with a wall at the front comprising a bottom section and a top section, with the bottom section extending further into the hearth than the top section, and the bottom section terminating in an upper edge in abutment with the top section, with a down-passage to an induction heater, located proximate the front wall, having an inlet in the floor at a location proximate the base of the front wall and up passage(s) having an outlet in the floor at a location in abutment with the base of the bottom section and with the bottom section being provided with a vertical slot extending upwards above the or each up-passage through it and opening onto the upper edge of the bottom section.

A refractory block assembly for a steam reformer furnace tunnel includes a hollow main body portion having at least one through-hole having openings formed in a first side and an opposed second side of the hollow main body portion. At least one refractory insert member, having mechanical mating features on at least a portion of the outer surface thereof, resides within at least one of the at least one through-hole of the hollow main body portion.

A refractory block assembly for a steam reformer furnace tunnel includes a hollow main body portion having at least one through-hole having openings formed in a first side and an opposed second side of the hollow main body portion. At least one refractory insert member, having mechanical mating features on at least a portion of the outer surface thereof, resides within at least one of the at least one through-hole of the hollow main body portion.

A refractory insert is provided, including a main body part having a first surface defining a first sidewall, an opposed second surface defining a second sidewall, and an outer peripheral surface separating the first and second surfaces, and a mechanical mating member provided on at least a portion of the outer peripheral surface thereof. The mechanical mating member includes a retention mechanism for controlling and retaining a position of a corresponding mating member in connection therewith.

A refractory insert is provided, including a main body part having a first surface defining a first sidewall, an opposed second surface defining a second sidewall, and an outer peripheral surface separating the first and second surfaces, and a mechanical mating member provided on at least a portion of the outer peripheral surface thereof. The mechanical mating member includes a retention mechanism for controlling and retaining a position of a corresponding mating member in connection therewith.

A refractory block assembly for a steam reformer furnace tunnel includes a hollow main body, at least one first mechanical mating member defining a protruded portion extending from an upper surface of the main body, at least one second corresponding mechanical mating member defining an opening corresponding to the protruded portion formed in a portion of a lower surface of the main body, and at least one through-hole having openings formed in a first side and an opposed second side of the main body portion. A refractory insert member having mechanical mating features on at least a portion of the outer surface thereof resides within the at least one though-hole of the refractory block.

A refractory block assembly for a steam reformer furnace tunnel includes a hollow main body, at least one first mechanical mating member defining a protruded portion extending from an upper surface of the main body, at least one second corresponding mechanical mating member defining an opening corresponding to the protruded portion formed in a portion of a lower surface of the main body, and at least one through-hole having openings formed in a first side and an opposed second side of the main body portion. A refractory insert member having mechanical mating features on at least a portion of the outer surface thereof resides within the at least one though-hole of the refractory block.

A heat-insulating protective member for skid posts contains a needled blanket of inorganic fibers. At least some of the needled blanket has, disposed therein, an impregnation part where an oxide-precursor-containing liquid is adherent in an undried state. The impregnation part has a water content of 50-400 parts by mass per 100 parts by mass of the inorganic fibers of the impregnation part. The water content of the heat-insulating protective member is 50-400 parts by mass per 100 parts by mass of the inorganic fibers of the heat-insulating protective member. The oxide-precursor-containing liquid contains ingredients that, upon burning, yield a composition containing Al.sub.2O.sub.3 and CaO. The oxide-precursor-containing liquid is adherent in an amount of 2-50 parts by mass in terms of oxide amount per 100 parts by mass of the inorganic fibers of the impregnation part. A molar ratio of Al/Ca, in the whole impregnation part is 10-330.

Provided is a block structure that may uniformly distribute a force applied by a charging material, a container including the block structure, and a construction method applied thereto. The block structure includes: a main body having one face extending in one direction and another direction perpendicular to one direction; and a plurality of blocks coupled to one face of the main body and being in contact with each other. Further, an engaged groove and an engaging protrusion are respectively formed on both opposed faces of each of the blocks, the opposed faces facing away each other in at least one of one direction or another direction.

Provided is a block structure that may uniformly distribute a force applied by a charging material, a container including the block structure, and a construction method applied thereto. The block structure includes: a main body having one face extending in one direction and another direction perpendicular to one direction; and a plurality of blocks coupled to one face of the main body and being in contact with each other. Further, an engaged groove and an engaging protrusion are respectively formed on both opposed faces of each of the blocks, the opposed faces facing away each other in at least one of one direction or another direction.