EMHA's Engineering department was commissioned by Bakker Sliedrecht to work on the redesign of a drive frame for a screw pumping station in the Alblasserwaard, with the production and installation of the new construction being carried out by our Machinery Installations department.
The screw drive has been substantially converted from an electrically stepped drive to a fully frequency controlled drive line. This conversion ensures more efficient drainage of the Alblasserwaard.
To further improve and permanently control the mechanism of vibration, noise, bearing and construction after this conversion, EMHA was asked to perform a vibration study and ODS (Operational Deflection Shape) on the machine frame. By providing insight into the vibration behaviour of the installation through an ODS, it was possible to determine where improvements could be made so that vibration levels could be continued at an acceptable level.
It turned out that the vibration levels of the existing installation could be slightly improved, this was the case for the existing machine frame in combination with a certain operating speed. After performing various calculations and analyses, it appeared that a new machine frame design and different type of bearing housings were the best solution to achieve a sufficiently stiff design. By applying FEM software (Ansys / Femap), the rigidity and natural frequency and of the new frame could be determined well in advance, which are crucial for correct functioning.
The new machine frame was then constructed in our workshop in H-I-Ambacht, after which it was machined tension-free and provided with a C4I coating system. In cooperation with our customer, the new machine frame, including the new motor, bearing housings, V-belts, etc., was then installed on site, with the assembly, anchoring and alignment of the drive line (pully alignment and shaft alignment) being carried out by our reliable and all-round service team.
After completion of the work, a test-run was carried out, during which EMHA again performed measurements on the new installation. Over the entire speed range, a vibration level was measured no higher than c.a. 1.5mm/sec, where 4.5mm/sec is permissible according to the applied ISO-120816 standard. Also compared to the initial design, the final result turned out to be very successful and above expectations for our client. Achieving this result further increased the reliability and lifetime of the entire installation.
Thanks to our unique mix of diverse disciplines and close cooperation between different divisions, EMHA once again proved to be a reliable all-round partner for this assignment.
