 |
|
RELIABILITY > CONDENSING DESIGN
KN Series is the correct design for a condensing boiler. The critical issue to minimize
condensate corrosion is the prevention of acidic concentration. This issue is
addressed in the design as follows:
-
The boiler is counter flow. I.e., the gas and water flows are in opposition such that the
hottest water (supply -at the top) feels the hottest gas temperature (below the burner
at the top) while the coldest water (return -at the bottom) feels the coolest gas
temperature (at the bottom). Thus, when the gas temperature has dropped sufficiently
to allow condensate to form, further cooling occurs as it travels toward the flue outlet
at the bottom of the exchanger preventing re-evaporation, the major cause of acid
concentration.
-
The boiler is designed to produce high gas velocity through the exchanger.
Condensate, as it forms, is 'blown' of the heat exchanger pins, reducing the
condensate thickness on the pins.
-
The condensate is collected on a tapered bottom pan and drained through a trap,
preventing 'pooling'. The thick aluminum pan and stainless steel drain connection are
coated with a high temperature corrosion resistant material.
|
