The multilayer structure is made by laying several elastic steel plates with heat resistance. At one end of the elastic steel plate there is a concave dust collector, the upper conical flange rotates together with the furnace body, and other end presses. Oven head or furnace tail sheath. The advantage of this sealing device is that it does not have machined parts, does not impose high installation requirements, and the wear parts that need to be replaced are resilient steel plates. Laminate fillings are common fish scale seals (see Figure 3-3). The sealing element is evenly distributed over the barrel of the rotary kiln. The sealing device consists of a steel cable, pulley and counterweight to reduce radial clearance and reduce radial seal between the sealing element and the rotating cylinder to achieve sealing. However, if the rotary kiln rotates for a long time, the radial clearance becomes large and the sealing device becomes less efficient.