In order to improve the sealing and insulation performance of tunnel kiln, avoid the influence of air leakage on the roasting process in kiln and the influence of high temperature gas on the metal structure of the lower part of kiln car, sand sealing grooves are installed on both sides of the kiln wall, and sand is filled in the groove. Sand sealing plates are inserted on both sides of the kiln car into the sand sealing groove to isolate the flow of upper and lower airflow. Liaoning magnesia-chrome brick

Aluminum silicate fibre module with thermal insulation and refractory material is installed on the kiln wall and top, which makes the thermal conductivity of the kiln smaller and does not lose heat, so as to effectively recycle the heat source and achieve the function of energy saving and consumption reduction. The structure of tunnel kiln is equipped with waste heat utilization system. The extracted hot air is used for drying bricks in drying chamber or for heating in winter in northern area. Generally, there is a kiln door at the inlet and outlet of the kiln, which makes the operation in the kiln stable and not affected by the outside world.