Flue Gas Temperature Fixing in Boiler

>135deg C, Boss, otherwise your stack will rot away.

Probably pretty close. AP/OP, the object is to stay above the acid gas dew-point (if you have any carbon steel construction), which depends largely on the fuel's sulfur content. Assuming you have a steel stack, the metal temperature must stay above the dew-point. The stack temperature also affects the draft available. What temperatures have the vendors proposed, and are they also providing the stack?

No idea. I think you are asking the wrong polooceman.

Well, yah. Most of it was addressed to AP/OP.

Perfectmo!

Whatever you do in the Boiler firebox- do not let the Flue gas out at less than 135C

What is the outlet temperature to you that it needs fixing?

What range do you want it to be fixed to and why? Unless I miss something the temperture in the boiler is more important.

The way I get your question is that you have fuels with different caloric value and therefore you have fluctuations in the boiler temperture.

Since you have two different fuels I think the idea was or should be to make the mix that goes in the boiler be of equal caloric value to maintain the boiler temperature.

Is this what you need to know, how to make sure the fuel mix is correct?

This "has" to be "G-up" yes? Seriously?

Dear Mr. Ramesh,

Pl. inform what is the Mix ratio of coal and husk, and moisture content in the husk.

Based on this, we have to calculate the condensing temperature of water vapour which remains in the flue gas in a super heated condition - as per DALTON's LAW of PARTIAL PRESSURE.

On seeing the detail, I will give the working and add 20 Deg. as safe margin and close the issue.

DHAYANANDHAN.S

Other posters have answered your question all as to the lower limits, 135 °C. There is a precise formula for this based on sulfur content in the gas.

One question remains: what about on the high side? Any elevated stack temperature above the design value (from the OEM), should be viewed with both eyes, one on the economics of not recovering heat value of the fuel in steam, and the other on possible tube damage, depending on which side of the tubes (inside or outside) is fouled/scaled. Does burning rice husks produce more tarry slag that will stick to the steam generator tubes?

You probably already have your answer to these questions.