| 摘要 |
The invention relates to a product filling pipe (1) to a packing machine for liquid contents such as milk. The filling pipe (1) consists of two concentric pipes (4,5) of metal which between them form a vacuum chamber (6). The double-walled filling pipe (1) is manufactured by the welding together in a vacuum chamber of two concentrically arranged pipes (4) and (5) along the annular weld joints (8) and (9). When a product which is considerably cooler than the surrounding atmosphere is supplied through the inner pipe (4) the outer pipe (5) will not be cooled down to an appreciable extent, since the evacuated space (6) in between constitutes a good thermal insulator. |
