Boiler blowing-out procedure

[wayuu1981]

Hello,

We are about to change the reheater tubes in two 150 MW coal fired utilities, we will change 75 panels in unit 1 (100% of primary reheater) and 96 panels in unit 2 (100% of primary and secondary reheaters).

I need to know what kind of blowing-out procedure do we need to perform in order to guarantee the right steam conditions at turbine inlet prior to operation. It is necessary to perform the same blowing-out procedure we used during plant erection ? (I mean, removing reheater steam valves at turbine inlet and install a temporary piping to atmosphere, and blow the same flow of steam as we have with the unit at maximum continuous rate), or, can we perform something simpler, considering we will only change reheater tubes, but we have the same water walls, steam drum, steam lines, SH and RH headers, etc.?

I’m asking this because the contractor that will change the reheater tubes will propose a blowing-out procedure and I need to establish the minimum requirements they have to include in their blowing-out scope.

I will appreciate your help

Javier Guevara E.
Projects Engineer


Javier Guevara E.
Projects, Mechanical Engineer
TERMOGUAJIRA - GECELCA S.A. E.S.P.

 

[metengr]

wayuu1981;
I would go with a simpler approach where if you have turbine stop valve screens installed to protect the HP/IP steam turbines, you may want to install fine mesh screens and operate until all debris has been caught.

We have never performed a steam blow after changing out superheater and reheater steam circuit tubing on an in-service boiler. For new boiler boiler construction, a steam blow is required because of the extensive amount of field welding.