Abstract: A grinding tool, for attachment to a grinding tool carrier in a grinding machine, comprises a core member (3) which is provided with means such as a central bolt (5) for attachment to a tool carrier (6), and has at least two segments (21) of grinding material disposed circumferentially about and permanently fixed by an adhesive to the core member, grooves being defined between the segments of grinding material. The core member with segments of grinding material is easily replaced without replacing the tool carrier.

Abstract: A jet pipe burner for heating the interior of an industrial furnace includes a jet pipe and a burner head positioned within the jet pipe. An air pipe and a gas pipe provide combustion air and fuel gas to the burner head. A gas-air mixer is connected to the air pipe and the gas pipe for mixing the combustion air and the fuel gas before they flow to the burner head. A valve, connected to the mixer, controls the supply of combustion air and fuel gas to the burner head. In one embodment a ring-shaped air duct is arranged coaxially with and laterally enclosing the burner head for cooling the burner, the ring-shaped air duct has nozzles which open into the jet pipe. A conduit connected to the source of combustion air delivers cooling air into the ring-shaped air duct. In another embodiment radially projecting cooling plates formed of heat resistant material are angularly distributed about the circumference of the burner head.

Abstract: In a generally elongated tubular burner heating element for the furnace chamber of an industrial furnace there is provided within the heating element at an end thereof opposite the end at which the burner is located a flame breaker assembly arranged to extend along the length of the burner heating element comprising a plurality of generally circular baffle plates spaced axially along the heating element and arranged basically in three groups. The first group of baffle plates which may comprise one or more plates and which is arranged closest to the burner comprises convex discs with their convex side directed toward the burner. The second group intermediate the first and the third group comprises a plurality of generally planer discs while the third group comprises concave discs having their concave side facing toward the burner.

Abstract: A jet pipe containing a burner extends through the interior of an industrial furnace. A seal for sealing the interior of the jet pipe from the interior of the industrial furnace, is positioned between an end face of the jet pipe and a flange having a recess in which the end face of the jet pipe seats. The seal is made of a material, preferably a lead-copper alloy, which is in the solid state when the temperature of the furnace is below a predetermined operating range and which changes into the plastic state as the temperature of the furnace increases and reaches the operating range of the furnace. Preferably, the seal is shaped as an annular member with a cylindrical extension having an outside diameter corresponding to the inside diameter of the jet pipe.