Duct wall surface structure

A duct wall surface structure of a duct,

• wherein the duct is formed from an iron-sheet material and is configured to flow a solid-gas two-phase stream containing solid particles therethrough,
• wherein the duct wall surface structure comprises a hopper which is provided at a lower end of the duct which is installed in such a direction that the stream has a vertical component of velocity and which is configured to collect the solid particles from the stream,
• wherein a low-rebound structure part, having a lower coefficient of restitution than the iron-sheet material of the duct, is provided in a region of an inner wall surface of the duct with which the solid particles collide, on an upstream side or a downstream side in a flow direction from the hopper,
• wherein the low-rebound structure part is a low-rebound structure part forming member which is installed opposing to and along the inner wall surface of the duct, the inner wall surface being inclined, and elastically deforms upon collision of the solid particles therewith, and
• wherein the low-rebound structure part is a large number of wires which is fixed on the inclined inner wall surface of the duct.