A Pressure Compounded Impulse Turbine is also called as Rateau Turbine after its inventor. Compounding steam turbines is done to extract energy more efficiently in a number of stages rather than a single stage. The compounding is done to reduce the increase in the entropy thus increasing the efficiency of the Steam Turbine.
![Pressure Compounded Impulse Turbine](https://z1c.906.myftpupload.com/wp-content/uploads/2022/02/Untitled-2-1024x747.jpg)
In this turbine, the total Pressure is dropped in more than one stage and each stage consists of a set of nozzles and moving blades. In every stage pressure is dropped and velocity is gained. The velocity thus gained is utilized in converting to useful work.
![Pressure Compounded Impulse Turbine](https://z1c.906.myftpupload.com/wp-content/uploads/2022/02/product-2-1-6.jpg)
As a result, the total pressure drop of the steam does not occur in the first nozzle but is distributed among all of the nozzle rings in the arrangement.