Electric air heater

An electric air heater, comprising:

• an outer casing, having an inner surface defining an inner cavity, a first end, and a second end,
• a refractory insulation layer in tight communication with the outer casing;
• a plurality of tubes extending axially through the inner cavity from the first end to the second end, the plurality of tubes each having an exterior surface,
• wherein the plurality of tubes is arranged radially around an axial center of the inner cavity,
• wherein each tube is fixed relative to the outer casing at the first end, and each tube has an electrical connection disposed at the first end,
• wherein each tube has a plurality of fins arranged extending radially from the exterior surface, and
• wherein each tube has an electrical heating element disposed axially through a hollow interior of the tube;
• and
• a sleeve supporting each of the plurality of tubes at the second end of the outer casing.

A method of heating air, comprising:

• directing a volume of air into an electric air heater,
• wherein the electric air heater comprises:
• an outer casing;
• an inner cavity disposed through the outer casing;
• a refractory insulation tightly fitted to the outer casing;
• and
• a plurality of tubes extending through the inner cavity,
• wherein the plurality of tubes is arranged into one or more layers;
• directing the volume of air through the inner cavity;
• and
• heating the volume of air.