Dynamic Movement: methods used and how to measure
Posted by: admin
on Jul 26, 2011 
Dynamic Movement: Temperature Changes Mean More than Hot or Cold
Dynamic movement, which also goes by the name thermal growth, is the change in length of metal that results from temperature change. If a metal bar is heated, it will elongate; it shrinks when cooled. The degree of change is dependent on the extent of temperature change and the individual metal.
The difference in the temperature of a machine during operation, as opposed to off line, will result in thermal growth. Manufacturers as well as engineers in other industries must take this into consider; the effects on a machine are significant to its bearings and supports.
Methods used to determine dynamic movement
Some dynamic movement can be predicted by information previously gathered; to some extent, the known thermal growth for a metal can help with theoretical calculations. Historic information as well as the theoretical calculations when combined determine manufacturer specifications. In addition, hot alignment checks show changes in machine alignment when it has reached its maximum operating temperature.
These methods, while helpful, are not adequate to the task of determining dynamic movement. To find the necessary information, thermal and torsion stresses must be measured while the machine is in operations to find the true dynamic movement within the machine. With measurement of these forces, a plan to compensate for them can be developed.
How dynamic movements are measured
It is vital that monitoring of a machine occurs through all the temperature variations it will undergo. Laser-based systems align coupling targets throughout the thermal range, and data is recorded and time stamped. Accurate alignment targets are designated, and the correlation of alignment changes with unites of time is made possible.
Who needs to monitor dynamic movement:
- Oil and Gas Industry
- Electrical Power Industry
- Petroleum/Chemical Industry
- Any industry where machinery undergoes temperature extremes
Examples of common machines with dynamic movement issues
Dynamic movement issues are common with Boiler fee pumps and must be measured wherever one is in operation in order to insure efficiency and minimize damage to coupling, seals and bearings.
Gas turbines especially need measurement of thermal growth due to extreme temperature that are found near their exhaust end.
Our thermal growth monitoring services facilitate maximum running efficiency and productivity. So, next time when you have any requirement for this service, please contact our offices immediately at 1-855ACQUIP1 or 1-855-227-8471 or by email at info@acquip.com