Abstract: The present invention discloses a ring dryer, comprising a housing, a top cover provided at the top of the housing, and a base provided at the bottom of the housing, and further comprising a feeding system into which the material to be dried flows, a material coating assembly, a material extrusion assembly, a discharging scraper, and at least two cylinders with different radii, wherein each of the cylinders is provided with a heat medium flow path inside, an annular groove is formed between the adjacent cylinders, and a material outlet is provided at a free end of the feeding system; the material to be dried in the feeding system flows into the annular groove along the material outlet; the material coating assembly, the material extrusion assembly and the discharging scraper are movably arranged in the annular groove and can move along the annular groove relative to the cylinders; and a blade of the discharging scraper is respectively in contact with an inner circumferential surface of the cylinder and an out

Abstract: The present invention discloses an exhaust gas catalyst for reducing the pollutant release containing in the exhaust gas. The catalyst includes a primary-core support carrier composed of gamma-phase aluminum oxide. The core-carrier is coated with Y.sub.2 O.sub.3 and ZrO.sub.2 such that the heat resistance is greatly improved. A two-layer active catalytic structure is formed over the core-carrier. An inner catalytic layer is formed with composition active catalytic elements with approximate weight ratios of La:Ce:Mn:Co:Pd:=10-15:10-15:6-10:6-10:0.1-0.3. An outer catalytic layer is then coated over the inner catalytic layer. The outer catalytic layer comprises catalytic active elements. The weight ratio of the active catalytic elements are Y:La:Zr:Cu:Cr:V:Pd:=1-3:2-6:2-6:6-10:10-15:2-6:0.1-0.3.