A packaged watertube boiler having two mud drums is referred to as the?

A packaged watertube boiler featuring two mud drums is known as an "A" type boiler due to its distinctive shell design that resembles the letter "A" when viewed from the side. This design facilitates efficient water and steam circulation within the boiler system. The two mud drums are strategically placed to collect sediment and facilitate better water flow, which enhances the overall efficiency of the boiler.

The "A" type design typically incorporates bent or sloped tubes that rise from the mud drums to the steam drum, promoting optimal heat transfer and steam generation. This configuration is beneficial in applications where space is limited, allowing for a more compact boiler design while still delivering high performance.

In contrast, other types mentioned, such as "O," "D," and three drum bent-tube types, refer to different configurations and designs that do not fit the specific characteristics of a boiler with two mud drums arranged in the "A" formation. Each design has its unique applications based on operational requirements and spatial constraints.