Pressurised hearth steam boiler

BA-S series

BIALSA pressurised hearth boilers are three-pass boilers with back flame.In them, the fire generated by the burner flows through the interior of the combustion chamber until it reaches the end of the combustion chamber.


Once the flame touches the bottom, it goes back inside the firebox itself until it reaches the front in its second pass, where it crosses the burner’s fire dart.


From there, it travels back inside the boiler, but this time along the inside of the tubes of the tube bundle to the flue in the third pass.
The crossing of flame flows in the furnace allows for complete combustion of all the fuel particles projected by the burner.


BIALSA generators of the BA-S series have a very favourable ratio between steam production and their evaporation and exchange surface, which translates into an optimum efficiency and steam output.

Technology and applied quality

Bialsa steam generators are built according to the TECHNICAL RULES FOR STEAM BOILERS (TRD) code, applying an exhaustive quality control, both in materials and manufacturing. The welds are made automatically by a submerged arc system, and are X-rayed before final assembly.


The cutting of sheets (quality P-265 GH) is carried out automatically by means of an oxycut system. The insulation is made of mineral rock wool, with a thickness of J 00 mm, and the final finish is made of stainless steel or lacquered sheet metal.


All BIALSA generators have a manhole in their upper generator, and cleaning mouths in the lower part, which ensures full and easy access to sludge and other materials that may be deposited inside.

Pressurized hearth steam boiler

Bialsa steam generators are divided into two groups; the BAS and BA-N series The BAS series are pressurized home generators with three smoke passages.


Inside, the dart of fire is introduced into the hearth, and after reaching the end of its journey, it returns back. This crossing of flame flows ensures complete combustion of the fuel particles projected by the burner.


Finally, the fire, after bouncing off the generator door, continues its journey through the tube bundle until it exits outside. The turbulence factor affects all types of fuel, liquid or gaseous.


BA-S generators have a very favorable ratio between steam production and its evaporation and exchange surface, which translates into optimal performance and steam title.

Three-pass boilers with back flame

The hearth, formed by a cylindrical combustion chamber, with a rear wall completely surrounded by water (wet room) and two smoke passages that lead the combustion gases to the gas expulsion duct.


This design offers multiple advantages, among which a low temperature in the combustion zone should be highlighted, which translates into low levels of nitrogen oxides (NOx) emissions and a high average performance.


Also with these BAN generators, the volumetric thermal load in the home is much lower, which also translates into a reduction in NOx levels.


The BA-N series is characterized by holding a large volume of water. This results in a significant thermal accumulation and a decrease in burner starts, causing a significant decrease in the levels of polluting gases and also giving a very favorable steam title.



Production capacity

From 100 to 2,500 Kg wh.


From 6 to 12 bars.

Caldera de vapor BA120S Vapor BA-N, generador BA-500N Biomass and fossil fuel steam boilers BA-N Series BIO-ENERGY BA-300 B, división de vapor BA-S Series BIO-ENERGY
Pressurised hearth steam boiler Biomass steam boilers Steam boilers with 3 flue gas passages


Some references

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