Design Studies on Turboexpanders for Dual Mode LOX-LIN Plant

Recognizing the technological and market void for a dual mode, i.e., liquid oxygen (LOX) or liquid nitrogen (LIN) mode of small to medium capacity air separation plant, a dual mode turboexpander-based air separation plant is proposed to be developed by BARC. The work described in this article begins with the preliminary design of turboexpanders for different modes of operation of the plant. The off-design characteristics of these conceptualized turbines are then used to size a single turbine to fit most of the modes of operation with varying levels of compromised performance in different modes. The article further describes the profile design of the selected turbine impeller using the Enhanced Midstream Method (EMDM). The turboexpander design and performance play a key role in the performance, operation and feasibility of the dual-mode plant.