3 replies to this topic

[bhdrsc]

Dear Sirs, 

In our plant, we have a furnace and waste heat boiler system. 

The refractory has been cured, but there has been formed some cracks on the ceramic tubes at the inlet of waste heat boiler. Despite those cracks are not so big, they are not too small, too.  

 

How can we understand that these cracks are important or not?

 

What are the crucial parameters to be considered for the refractory inspection?

[rajprocess]

dear,

 

Firstly check the temperature trends of dryout to ensure temperature rampup has been taken place as per the procedure in accordance to refractory supplier.

Fine cracks on the refractory is good ,as these cracks will take the thermal expansion once you start the unit.

Refractory inspection is done visually /hammer test by the refractory inspector.usually 1-2mm cracks are ok , but it is judgemental by refractory inspector , basically refractory inspector should be very skilled and experienced who takes into consideraion of crack orientaion/propagation.

 Look in to API 936 for more details pertaining to refractroy.

 

 

 

 

[bhdrsc]

I understand that refractory anchors need to be checked? Do the cracks affect the life of furnace? 

[rajprocess]

there is no means of checking the anchors once the refractory application done.

Yes, the cracks obviously affects furnace, if shell temperature increases. generally shell  material is CS with design temperature ~340 °C where as the temperature in the fire box are more than 600 °C