3 replies to this topic

[s.vf]

hi all
i have one question about preheaters,
can we use the rotary preheaters for boilers and fire heaters with" natural draft system"?
or we are obliged to change the natural draft sysem to forced draft and then use preheater?
thanks if someone answer me

[djack77494]

I think you're referring to something like a Ljungstrom type of rotary combustion air preheater. Since you are basically "pushing" your incoming air through something resembling a packed bed, I suspect that you would need a fan upstream of the heater to supply the needed motive force. I've seen this situations in many installations, but have not seen one without a forced draft fan.
Doug

[fallah]

We can also use Induced Draft Fan(I.D.Fan) downstream of the combustion chamber for producing motive force.

Regards

[djack77494]

We can also use Induced Draft Fan(I.D.Fan) downstream of the combustion chamber

While it is theoretically possible to use an induced draft fan as indicated, I doubt you will see many installations configured that way. In simple terms, it tends to be more practical to motivate cooler, denser gases than warmer, leaner gases. Thus, I would favor the Forced Draft Fan in these situations.
Doug