DEVICE FOR MODIFYING THE NATURAL FREQUENCY OF A VERTICAL PUMP, VERTICAL PUMP AND METHOD FOR RETROFITTING A VERTICAL PUMP

摘要

A suppressing device is proposed for shifting a structural natural frequency of a vertical pump, said pump (1) comprising a pumping unit (2) with an inlet (21) and an impeller (22) for conveying a fluid, a discharge unit (4) with an outlet (41) for the fluid, a drive unit (5) for rotating the impeller (22), a column pipe (3) extending in an axial direction (A) and having at least one column element (31) with an axial length (C), said column pipe (3) connecting the pumping unit (2) with the discharge unit (4), as well as a line shaft (6) extending within the column pipe (3) and operatively connecting the drive unit (5) with the pumping unit (2), said suppressing device (10) being designed and adapted for closely fitting around the entire circumference of the column element (31), and having an extension (L) in the axial direction (A) which is at least half the axial length (C) of the column element (31) and comprising at least one rib (11) extending essentially in a radial direction being perpendicular to the axial direction (A). In addition, a vertical pump is proposed comprising such a suppressing device (10) as well as a method of retrofitting a vertical pump.