The SG Firetube Boilers are our direct fired two pass wet back boilers. The burner fires down the center of the firetube, which is located on the lower half of the boiler. The flame travels down the firetube and enters the inversion chamber. The exhaust gases then travel from the inversion chamber through the combustion tubes and exit the boiler through the exhaust stack. The wet back design refers to water at the back of the boilers inversion chamber thus eliminating the need for refractory. Another feature is that the tubes are both expanded and welded to the tube-sheets.
The SG Firetube Boilers are only available in a two pass design. The two pass design has a more balanced heat transfer from the tube to the water than a three pass design. The optimized heat transfer lessens the thermal stresses on the structure and helps mitigate cracking or deformation. In comparison, the third pass of a three pass boiler has negligible heat transfer improvement while it has the potential to expose the tubes to corrosion (dew point).
The SG can be supplied with a variety of forced draft burners provided by some of the world’s leading burner manufactures. This allows us to utilize a variety of fuels, meet stringent emissions requirements, and even allow our customers the opportunity to select the burner of their choice.
The SG-PA is our high efficiency option of the SG Firetube Boiler. The SG-PA is constructed in a horizontal orientation and is supplied with a combustion air preheater at the burner side of the heater.
The SG-ECO is our feed water preheater option of the SG Firetube Boiler. The feed water preheater utilizes an economizer to preheat the water entering the steam generator. This in turn, enables the customer to obtain optimum performance of the generator by supplying the necessary feed water temperatures to the Firetube Boiler.
The SG, SG-PA, and SG-ECO Firetube Boilers are designed and constructed to various local code requirements around the world. The most common codes are ASME with National Board registration for the United States, CRN for Canada, and CE/PED/TUV/DIN for Europe. Additional code requirements may be met if necessary.
Package and containerized systems are available for both the SG, SG-PA, and SG-ECO Firetube Boilers. These package systems can be customized to meet each of our customers’ needs, including but not limited to: control panel, feed water pumps, feed water treatment, deaerator, feed water tanks, ladders and platforms, and ancillary components. These auxiliary components are typically fabricated in the USA for USA/Canada installations.
Firetube boilers are a form of large water content boilers used to provide customers with steam as a heat transfer media. Typically, the quality of steam provided by these units is much higher than forced circulation steam generators. The higher quality of steam mitigates the use of steam separators or steam accumulators.
Two Pass, Wet Back Design
Combustion Air Preheater Optional