Study on the efficiency of a transducer for sonochemistry by calorimetry

Sonochemistry is an effective method for initiation or enhancement of the chemical reactions by ultrasound in a wide range of applications. In this study, the efficiency of a sonochemistry transducer, defined as the ratio of ultrasonic power to electrical power, was investigated for different materials and the thicknesses of the vibration plate in the frequency range 22 kHz–2 MHz. The ultrasonic power was measured by calorimetry. To eliminate the influence of reflected waves, the transducer was attached to the side of a cylindrical vessel. The transducer with a stainless-steel vibration plate was more efficient than those with vibration plates of acrylonitrile butadiene styrene plastic or chloroprene rubber. The efficiencies of the transducers also increased with decreasing thickness of the vibration plates. Langevin-type transducers were less efficient than the disk-type transducers.

A SIMILARITY CRITERION FOR SPHERICAL FUEL ELEMENTS FREE FALL VELOCITY IN CYLINDRICAL CHANNELS WITH VISCOUSE LIQUID

The introduction of nuclear high-temperature gas-cooled reactors (HTGR) with an active zone based on spherical fuel elements (SFE) poses the task of determining the velocity of their free fall in cylindrical channels with a viscous liquid. To solve it, the experimental data of other researchers are generalized, and for a certain range of Reynolds numbers the criterion of similarity for the velocity of free fall of spheres in cylindrical channels with water is found. The criterion is formulated on the basis of the Freud number. It is shown that from the dependence of the velocity of falling of the model sphere in a cylindrical vessel with water on the dimensionless diameter of the sphere, it is possible to determine the velocity of falling of the sphere in water, arbitrary.

Influence of Explosion Chamber Shape on Timing Parameters of Disperser

A standardized device with a volume of 1 m3 or 20 L is used to determine explosion parameters. An explosion chamber where explosion takes place is of a spherical or cylindrical shape that suits the shape of a cubic container. In the case of a cylindrical vessel, the diameter and depth of the vessel are 1: 1. In this case, it is a spherical vessel with a volume of 365 liters. Time parameters of the disperser in the spherical vessel are compared with those of a truncated spherical vessel with a volume of 291 liters. Comparison of the measurement results showed that the optimal delay time of the explosion chamber with a volume of 291 liters is 290 ms, while the delay time of the explosion chamber with a volume of 365 liters is 350 ms.