| 摘要 |
A Coriolis flowmeter having a single flow tube surrounded by connecting rings and a balance bar whose ends are connected by the connecting rings to the flow tube. The balance bar has a thermal coefficient of expansion greater than that of the connecting rings and the flow tube. The outer circumferential surface of each connecting ring is tapered toward the axial center of the flow tube. The inner circumferential surface of the balance bar has a taper matching that of the connecting ring. The connecting ring can only be partially inserted into the space between the flow tube and the balance bar when the assembly is at room temperature. Braze material is then applied to the visible ends of the surface common to the balance bar and the connecting rings as well as to the ends of the surface common to the connecting rings and the flow tube. The structure is heated to brazing temperature to braze these common surfaces. The greater thermal coefficient of expansion of the balance bar enables the tapered connecting rings to be fully inserted into the space between the balance bar and the flow tube so that the outer ends of the connecting rings are coplanar with the ends of the balance bar. Another embodiment has a step on the inner surface of the balance bar that limits the inward axial travel of the connecting rings. Another embodiment has an annular ring between the flow tube and the connecting ring to reduce the peak stress. |
