We examine what superheated steam is, and why it's sometimes necessary to desuperheat it. We also cover the types of desuperheater available, where they're used and how to install them.
First we cover the issues to think about when selecting a desuperheater, such as turndown ratio. Then we survey the types of desuperheater available, including indirect contact, direct contact, water spray, and axial injection desuperheaters. Consideration of the advantages and disadvantages of each is offered.
The difference between superheated and desuperheated steam is detailed, where both types of steam are typically used, and calculations for desuperheating.
A range of other desuperheaters are commonly used. Here we look at venturi type, steam atomising, variable orifice, combined pressure control valve and desuperheater, and compare the options alongside one another.
There are a range of factors that must be considered. This section looks at key issues, including the properties of the cooling water itself, the installation of the desuperheater, pressure control, and sensor positioning.