Tunnel type roasting furnace

The utility model provides a tunnel type roasting furnace which comprises a base, a shell, an exhaust system, a heating pipe, an inner pipe, a conveying device, a conveying belt and a tunnel body, the shell is fixedly arranged on the base, a plurality of supporting columns are arranged in the base, one end of each supporting column is fixed to the bottom of the base, and the other end of each supporting column is fixed to the bottom of the shell; the heating pipe is arranged in the shell, the inner pipe is arranged in the heating pipe, and the exhaust system is arranged at the top of the shell, so that the problem that the inner pipe is easy to swell or crack due to thermal expansion and cold contraction in the roasting process is solved. 本申请提供一种隧道式焙烧炉，包括：底座，外壳，排气系统，加热管，内管，运输装置，传送带以及隧道本体，所述外壳固定设置在所述底座上，所述底座内部设有多个支撑柱，所述支撑柱一端固定在所述底座底部，另一端固定在所述外壳底部，所述加热管设置在所述外壳内部，所述内管设置在所述加热管内部，所述排气系统设置在所述外壳顶部，以解决焙烧率在焙烧过程中内管由于热胀冷缩容易造成鼓包或裂缝的问题。