Rotary hearth furnace, and method for producing reduced iron using rotary hearth furnace

A rotary hearth furnace suitable for producing reduced iron by reducing iron oxide by heating agglomerates comprising iron oxide, the rotary hearth furnace comprising:

• a furnace body comprising a pair of peripheral walls and a ceiling plate that enclose a ring-like space having a continuous ring-like shape at lateral sides and an upper side of the ring-like space, respectively;
• a ring-like hearth portion which forms a bottom portion of the ring-like space and which is rotatable in a predetermined rotational direction;
• a gas exhaust portion for discharging an exhaust gas generated in the ring-like space an outside of the furnace body;
• an introducing portion;
• and
• a flow rate regulating portion,
• wherein the ring-like space having a heating zone where the agglomerates placed on the hearth portion are heated and a non-heating zone where the agglomerates are not heated, the heating zone and the non-heating zone being joined with each other in a ring-like shape thereby forming the ring-like space,
• wherein the gas exhaust portion is disposed in the non-heating zone,
• wherein the introducing portion is disposed upstream of the gas exhaust portion in the rotational direction and is configured to introduce a pressure regulating gas for regulating a pressure in the ring-like space into the non-heating zone,
• wherein the flow rate regulating portion is disposed between the introducing portion and the gas exhaust portion in the non-heating zone and is configured to regulate a flow rate of a gas which flows through the non-heating zone by adjusting an opening area of the non-heating zone, and
• wherein the flow rate regulating portion is configured to regulate a flow rate of a gas which flows through the non-heating zone such that a pressure at a boundary between the heating zone and the non-heating zone, the boundary being a downstream end of the heating zone in the rotational direction, becomes the highest in the ring-like space.