Vol 106, No 8 (2017)

The paper describes the principal of a vortex tube operation, its main advantages as compared with throttling devices regarding the temperature efficiency and specific refrigerating capacity as well as the spheres of application for moderate pressure gases. A test bench was developed to study the operation of a vaporcompression refrigerating machine (VCRM) with a vortex tube as an expander. The scheme and the test results of the unit with a needle nozzle - throttle are given; refrigerating capacity, energy consumption and energy efficiency ratio of the unit were calculated and specified. A calculation algorithm, main dependences and characteristic equations to take into account natural convection of the environment with a reservoir of cooled 50% ethyleneglycol solution are presented. The choice of the used refrigerant is based, its properties are described. Intermediate conclusions based on the test results are cited; a planned replacement of the expander on the vortex tube is grounded; it is shown that it is necessary to conduct tests using the unit constructively improved together with the comparative analysis of the results.

When granulating the main task is to select rational conditions of the process of freezing liquid suspension granules. The determination of freezing time of a liquid drop at nitrogenous temperatures including in a dimensionless form, at different stages of the process as well as under different conditions of its behavior allows revealing rational conditions of this process and offering recommendations to hardware design of an immersion cryogranulator. The recommendations make it possible to select its main geometric dimensions with higher foundation.