| 摘要 |
The invention describes a plastic air heating pipe made from double plastic sheet manufactured by extrusion from a flat or circular mould. By heat welding along the length of the seam, the plastic air heating pipe is divided into a support region and a region for circulation of the heating air. It thus solves the problem of destruction of simple plastic air heating pipes by the large amount of friction which develops at the support points, eliminating additional frictional loss in the course of air flow due to local narrowing of the cross section at the support points and makes the process of installation on the frame of the greenhouse much quicker and easier. |
