Eurovib (Acoustic Products) Ltd.

A large industrial plant had a problem associated with a Kiln Extract fan. The vibration sensors on the fan bearing repeatedly tripped out due to excessive vibration. The result as that the fan and hence the Kiln could only be operated at a much reduced duty.

On examination it was found that although the fan had been adequately isolated from the structure the aspect ratio of the fan was such that the Center of Gravity was far above the plane of the mounting points. Additionally there was a build up of matter on the fan impeller which exaggerated the problem and this had to be addressed also.

Initially the fan had to be de-commissioned and the fan and local area cleaned. The fan, located on the fourth floor and weighing in excess of 40 tonnes, had to be raised in order to blank off the underside of the base frame. The frame was then filled with concrete in order to mimic an Inertia Base and lower the Center of Gravity as far as possible (in fact it was impossible to lower this to the ideal point as the frame was not physically large enough to accommodate sufficient concrete). The mounts then had to be uprated and replaced to support the fan and the additional weight of the base frame.

The fan was the re-commissioned and the problem was solved.

The mounts to support the assembly cost a little under £3500.00 in total but this was minute compared to the cost of the remedial work to alter the fan assembly and fit the mounts. The cost of running at reduced production capacity was in excess of £100,000.00.

All of the above could have been avoided if the correct advice had been sought during the design stage and all of the additional costs above could have been avoided.