Possible causes were unbalance due to dirty or damaged fan blades or a problem with the gearbox mounting structure.
Cooling tower fan blade balancing.
Here s the outside and inside.
The equipment we have balanced ranges from small blowers to the largest of cooling tower fans.
This document is intended to apply specifically to system vibration and mechanical balancing as related to fans and blowers.
The purpose of a cooling tower is removal of excess heat from water used in industrial processes to cool various systems.
And the fan has three fiberglass blades.
The air movement and control association intl inc s amca standard 204 balance quality and vibration levels for fans recognizes five different fan application categories bv 1 bv 2 bv 3 bv 4 and bv 5 for the required balancing grade during manufacturing of the fan see table.
Fan speed motor speed blade pass frequency.
Dynamic balancing of the cooling tower fan.
Thru balancing of the cooling tower fan we were able to reduce the 1x rpm fan vibration levels significantly from 72 mills to 2 5 mills at 330 rpm or from 19 mills to 0 6 mills at 240 rpm.
The fan was balanced to 0 5 mils but there was a high 0 65 in sec at 1200 cpm.
We also offer shop services balancing motor armatures flywheels and crankshafts.
This document covers impellers while systems see amca standard 204 and ansi standard s2 19 are covered by air.
Dynamic balancing cornell balancing offers on site service to perform single and two plane balancing service of all rotating equipment.
A likely structural natural frequency was identified at 310 cpm.
Frequencies present at cooling towers.
The principles presented however can be generally applied to many rotating components.
No overall vibration level standards are offered by cti.
Where is the 0 65 in sec at 1200 cpm coming from.
I m balancing a fan with a speed of 348 rpm and the motor speed is 1800 rpm.
These balance categories are ordered from a less sensitive group hvac to the most sensitive fans which include those for petrochemical processes and computer chip manufacturing.
The air flow is produced by the fan which is driven by the motor either in direct drive or by gear speed reducer.