Double-layer two-way material conveying device

Corresponding chain links of two parallel chains are connected through two-way pore plates, the width of each two-way pore plate corresponds to two chain links, each two-way pore plate comprises a low pore surface, an inclined pore surface and a high pore surface which are sequentially connected into a whole, the width of the low pore surface is larger than that of the high pore surface, and the width of the inclined pore surface is larger than that of the high pore surface. The edge of the low-hole surface is provided with a low-side folding edge which is bent downwards, the edge of the high-hole surface is provided with a high-side folding edge which is bent downwards, the lower edge of the high-side folding edge is flush with the top surface of the low-hole surface, and the back surface of each two-way hole plate is provided with a plurality of hole plate reinforcing ribs; the low hole faces are located on one side of the forward direction of the chain, the two ends of the low hole faces are fixedly connec