work underway on a water-discharge structure we designed for poor soil conditions
project filter
downloadable resources
back to projects

steam-line evaluation

steam-line evaluation
Minnesota Power

analysis and modification options help push project forward

Minnesota Power wanted to evaluate potential modifications for a paper machine at its Rapids Energy Center. The proposed tie-in would direct steam in a singular path that would allow use of desuperheaters to reduce steam temperature and provide better operating control.

After performing an initial evaluation, we suggested a review of the 50-pound steam line to determine actual pipe routing, existing turbine loading, defective support locations, and sagging piping locations.

We performed 3D scanning to create a model and develop a baseline of the existing system. By conducting a pipe stress analysis, we compared existing forces and moment loads to the original allowable design loads and identified problem areas. Issues existed with pipe supports, horizontal pipe sag, and exceedances in allowable turbine force and moment loads.

Barr recommended two options for analyzing the piping system before modifying tie-in and pipe and routing supports. We then analyzed three load-case conditions, calculated the loads, and compared them to the original design loads. We also presented two support options with pipe routing and turbine-nozzle load variations. 

The analysis and modification options we presented allowed Minnesota Power to make an informed decision for moving forward with the project. Barr is currently assisting the client with constructability of the new tie-in and hangar modifications and assembling a contractor bid package; we will also provide support during construction.