立式罐底量增量研究及应用

Study and Application of the Bottom Volume Increment of Vertical Tank

立式罐底量变化对大批量液体计量精度的影响一直没有很好解决。通过对立式罐底量三种基本状态及增量的研究分析,提出了立式罐底板变形规律的概念,并绘出了变形规律曲线,曲线分三个区域,第Ⅰ区内罐底板状态与空罐时相同,不发生任何变形,无底量增量,空罐容积表保持有效;第Ⅱ区为弹性变形区,底量增量产生且不断变化,改变液位与容量关系,空罐容积表失效;第Ⅲ区为稳定区,罐底板总体处于稳定状态,增量保持恒定,空罐容积表不再适用,必须进行实罐容积表修正。三个区的临界点及第Ⅱ、Ⅲ区中增量值一经确定,就确定了对应立式罐的底量增量变化规律,按此规律设计的测试方法及编制的实罐容积表计量精度为0.1％。

The influence of the volume change of vertical tank on liquid block measurement precision has not be conquered ever since. This paper, through analysis on the three basic states and increment of bottom volume, introduces the concept of bottom deformation pattern, and presents the curve of deformation pattern. The curve consists of the following three zones:① The bottom plates in Zone I will experience no deformation when the tank is filled, therefore, no volume increment will occure and the strapping table for the empty tank will keep valid;②Zone Ⅱ is a zone of elastic deformation, where the bottom volume will increase and change constantly, resulting in variable level-volume relation and the invalidation of strapping table;③Zone Ⅲ, being a stable zone, will have a stable state of bottom plates and a constant volume increment, and it is required to carry out a strapping table correction for real tank volume to replace the invalidated strapping table for empty tank. Once the critical points for the three zones and the increments for Zone I and I are available, the corresponding change pattern of bottom volumetric increment can be determined. The measuring method and strapping table obtained on the basis of this pattern can achieve a measurement precision of 0. 1%.