High temperature in boiler wall

[sumon emam]

Recently failure of some tubes of superheater of the power boiler (water tube) occurred in our plant. We have to remove 2 coils (out of 54) and the remaining portion is plugged. This plugged portion is kept under refractory. We have plan to replace the superheater coil as soon as possible after procurement.

But recently it is found that the wall beside the superheater and opposite to the burner is overheated. There are two layers of refractory bricks and also refractory casting lining. The refractory is found in good condition. But the reason behind this increase in temperature is not identified.

Can anyone help us what is/are the possible reasons behind the problem and measures to be taken to rectify it?

[A.Venugopal]

Dear friend,

It is understood from your description that high temperature gases were tocuhing the superheaters as the heat absorption surfaces are all refractory lined. Correct ? I think in order to get some review , you need to add data on fuel, its anslysis, flow rate, air temperature , unit operating pressure, desired temperature of steam at S?H outlet. The designer would further ask a lot of questions to review the unit . You may add all the three views of GA drawing of the boiler pressure parts . Plus what ever are your observations , how so ever absurd they may look like. You may please post as much exhaustive details as are available on the boiler to enable others to come to your help.

Bye and best regards

Venugopal