Three Pass Boiler (Definition)

Three-pass boiler - this is a type of heating boiler, which has three separate paths (passages) for the flue gases before they leave the boiler through the chimney.

Three-pass boiler: main features

• First move: Hot flue gases from fuel combustion pass through the first part of the heat exchanger, where intensive heat transfer to the coolant occurs.
• Second move: The cooled gases are directed to another part of the heat exchanger where they transfer the residual heat.
• Third move: The finally cooled gases are directed to the third section of the heat exchanger before leaving the boiler through the chimney.

Advantages:

• High efficiency: Due to the multiple passage of flue gases through the heat exchanger, the three-pass boiler achieves high efficiency, making maximum use of the heat of combustion of the fuel.
• Uniform temperature distribution: This design promotes uniform heating of the coolant.
• Reducing heat loss: Due to the multiple passage of gases through the heat exchanger, heat loss is reduced to a minimum.

Three pass boilers are often used in industrial and commercial applications, as well as in central heating systems where high efficiency and reliability are required.