Our (the World) fuel supply resources are limited and non-replaceable, the cost of drilling, extracting, and transporting increase as we go deeper and further afield into more difficult locations and hostile environments. Conservation is a necessity considering the present competitive world and our huge trade imbalance. Heat recovery from boiler flue gas is an important part of the field of Energy Management and Conservation.
This bulletin covers the general engineering principles of our flue gas heat recovery unit or economizer, trade named "HEATMIZER", with condensing capability designed specifically for boilers 100 to 1500 HP in size and for lower temperature water heating as a well as standard boiler feedwater heating.
The model FGL unit utilizes the pressure available from the boiler-burner forced draft fan to overcome the added flue gas pressure drop of the HEATMIZER. The HEATMIZER normally adds approximately 0.5" WC. pressure to the boiler firebox pressure.
Also available are the model IGL and BGL units that are supplied with an integral draft fan and automatic draft control system to overcome the draft loss through the HEATMIZER and regulate the draft to a constant preset amount usually in the range of -0.05" to-0.10" WC. to approximate the draft that originally existed at the boiler outlet. These models are normally used where two or more boilers are connected to a horizontal breeching not designed for positive pressure or for boilers that are not pressure tight.
The FGL HEATMIZER is compact and lightweight, using SS or Cu tubes and aluminum plate fins for the heat exchanger. It is mounted directly on the horizontal firetube boiler flue gas outlet when ceiling height permits, making the most economical and easily serviced unit.
1. Reduce fuel consumption by reclaiming energy lost in exhaust stack.
2. Extend performance of existing installation by adding additional heat transfer surface.
3. Reduce thermal shock to the boiler by preheating the feedwater.
The water treatment program is a vital part of the efficient and proper operation of a boiler and HEATMIZER. It is the responsibility of the user to provide:
1. Controlled hardness to avoid scale.
2. Sufficient alkalinity (PH) to reduce corrosion and to keep silica in solution.
3. Freedom from oxygen and other dissolved gases to avoid oxygen corrosion for boiler feedwater applications. (Boiler deaerator or oxygen scavenger)
4. Freedom from suspended solids (sludge) to avoid clogging and erosion.
5. Controlled dissolved solids by proper blowdown.
CAUTION: Effective water treatment equipment must be operating prior to HEATMIZER or boiler startup.
1. Designed for condensing operation for heating cold makeup or domestic water with condensate separation and drainage of both HEATMIZER and exhaust stack.
2. Removable heat exchange elements for cleaning or repair.
3. Counter flow heat exchange for maximum efficiency.
4. Removable inspection plates for easy examination of heat exchanger surfaces.
5. Built-in flue gas bypass for temperature control or for bypass of fuel oil firing.
6. Dial thermometers mounted on unit: One each on flue gas inlet, outlet, water inlet, and outlet.