Type .03 DA atmospheric deaerators are recommended for low-pressure boiler applications. The standard .03 design removes dissolved oxygen to a maximum level of .03 cubic centimeters per liter of feed water. The amount of hot condensate returns influences which design is most appropriate for applications. A single-compartment .03 DA unit is typically used on systems having 80% or more make-up water. Two-compartment design (.03 DA-2C) or two-tank design (.03 DA-2T) that includes a standalone surge tank is typically used on systems having more than 20% return hot condensate.
Two-compartment deaerators also recommended:
- where floor space may not be sufficient for a two-tank design
- when a complete, factory-packaged unit is preferred instead of field wiring and piping of a free-standing surge tank and deaerator
The two-compartment design enables the flash steam that escapes the deaeration compartment to be recovered by the direct contact vent condensor in the accumulator compartment. This method allows minimal vent loss.
Standard deaerators receivers available in black steel. On two-tank designs the free-standing surge tank can be plasite-lined or made 300 series stainless steel; on two-chamber designs, the surge tank can be plasite-line or the complete tank made 300 series stainless steel. Unit can built to handle a wide range of flows and pressures; receiver can be customized in terms of diameter, length and height to meet job specific requirements.
Number of pumps on unit depends upon number of boilers to be supported and stand-by specifications. Pump motors can be either 1750 RPM or 3500 RPM, single or three phase. Unit equipped with single stage or multi-stage pumps depending upon operating conditions. Pumps typically bronze-fitted with industry standard motors and mechanical seals rated for temperatures up to 300°F. Higher temperature seals and special faces available upon request. Pumps can be mounted in either a vertical or horizontal orientation.
Deaerators equipped with direction steam injection assembly with stainless steel preheat tube; assembly includes temperature regulator that can be either pneumatic controlled or self-contained. Other accessories include but not limited to gauge glass assembly thermometer, inlet strainer, butterfly isolation valve, low-water cut-off or alarm switch, electrical control panels and tank insulation.