The invention relates to a spiral conveyer with special
pipe walls. The spiral conveyer comprises a horizontal conveying tube, a spiral
propeller horizontally and coaxially arranged in a cavity of the conveying tube, a material inlet communicated with the upper portion at one end of the conveying tube, a material outlet communicated with the lower portion at the other end of the conveying tube, and a motor in power connection with one end of the conveying tube close to the material inlet. The conveying tube comprises a small-
diameter section cavity, a transition section cavity and a large-
diameter section cavity which are sequentially connected, and the internal diameters of the small-
diameter section cavity, the transition section cavity and the large-diameter section cavity gradually increase from the material inlet to the material outlet. The section of the small-diameter section cavity is cylindrical, the section of the transition section cavity is in the shape of a cone with big belly and
small mouth, the section of the upper portion of the large-diameter section cavity is in the shape of a semicircle, and the section of the lower portion of the large-diameter section cavity is in the shape of a semiellipse. The spiral
propeller comprises a rotating shaft and spiral blades. The spiral blades are in a uniform
pitch and variable diameter mode, and gaps are reserved between the spiral blades and the inner walls of the large-diameter section cavity and the small-diameter section cavity. The spiral conveyer with the special
pipe walls can achieve continuous pulseless feeding and can reduce influence on feeding caused by discharging
impact.