| 摘要 |
PURPOSE:To enable sufficient heat exchange to be performed by a single pipe, by using a composite pipe made of a hydraulic inorganic material or a plastic coated with the inorganic material and provided with at least one metallic wall or metallic finned partition wall for partitioning the interior of the pipe into a plurality of speces along the axial direction over the entire length of the pipe. CONSTITUTION:Two tubular passages 14, 15 are defined by the pipe 11 and the partition wall 12. Since intake and exhaust can be conducted by the single pipe, it is sufficient to provide only one piping, and since the partition wall has favorable thermal conductivity, heat exchange is achieved between the intake pipe and the exhaust pipe at intermediate parts of the piping, whereby loss of heat is reduced. In addition, since the pipe itself or the coating material is an inorganic substance, the quantity of heat radiated is small. Next, the composite pipe can be produced by a method wherein a pipe 11 devoid of the partition wall 12, 16 is formed in a tubular form by applying a paste obtained by kneading a cement mortar, an aggregate, a fibrous reinforcing material, a molding adjutant and water to the outer periphery of a core having a shape cooresponding to the inside shape of a desired pipe, and after drying, the core is drawn out. |
