Energy-saving tunnel kiln for producing coal gangue bricks

The utility model discloses an energy-saving tunnel kiln for producing coal gangue bricks. The tunnel kiln comprises a heating kiln body, heating chambers are evenly arranged in the heating kiln body,the tops of the heating chambers are communicated with a smoke pipe, one side of the heating kiln body is communicated with a feeding cavity, preheating plates are arranged on the two sides of the inner wall of the feeding cavity, and the preheating plates are filled with preheating pipelines. According to the utility model, the preheating plate and the flue gas pipe are arranged; a heating chamber in the heating kiln is used for heating the molded bricks to mold the molded bricks; flue gas generated in the heating process is exhausted through a flue gas pipe; the flue gas pipe conducts fluegas to a preheating pipeline in the preheating plate and conveys the flue gas in the preheating plate in a surrounding manner; and the temperature of the preheating plate is increased by the temperature in the high-temperature