Booster turbine expansion machine, the working medium of this unit is pressurized by the booster first, and then enters into the main heat exchanger after cooling, and then enters into the expansion machine for adiabatic expansion to generate the cooling required by the air separation unit, at the same time, the mechanical power produced is absorbed by the booster
The working medium enters the volute through the inlet pipe, then enters into the working wheel to work through the adjustable nozzle, and then is discharged through the expansion chamber and exhaust pipe.
The air volume adjustment of the expansion machine is realized by the pneumatic film actuator installed on the top of the cold box to drive the blade of the nozzle to rotate, thus changing the sectional area of the channel, the stroke of the valve stem of the actuator reflects the change of the width of the nozzle channel. The total stroke of the valve stem is about 40mm. The downward movement of the valve stem makes the nozzle channel wide, while the upward movement makes it small.
Volute: it is welded with stainless steel structure, fixed on the fuselage, connected to the base through the fuselage, and the content of volute includes nozzle and expander impeller.
Rotor: the two ends are respectively equipped with the impeller of the expansion machine and the impeller of the booster (both of them are closed), which are a rigid rotor, fitted on the bearing of the body.
Bearings: both front and back bearings are radial thrust combined bearings, and clean and sufficient lubricating oil is supplied by the inlet pipe to make the rotor run stably for a long time. Platinum resistance thermometer is adopted to measure the bearing temperature.
Shaft seal: there is a maze seal sleeve on each shaft which is close to the second impeller to control the gas leakage within the minimum range, fill the sealing sleeve near the expansion machine with normal temperature Sealing Gas (dry air or nitrogen) to prevent the low temperature gas flowing through the expansion machine from leaking, and run "cold ", in order to control the pressure difference between the gas at the nozzle outlet and the sealing gas at the expansion machine end to maintain around 0.05MPa, a precise pressure reducing valve is specially set up to fill in the sealing sleeve of the booster end ~ Sealed Air (dry air) with a pressure of 0.5MPa ).
