Проведено експериментальне дослідження середньої товщини плівки, гальмівного впливу стінки на рідину в роторно-плівковому апараті з висхідним потоком.
Intensification of heat and mass transfer processes in liquids most simply solved by using thin-film equipment. Organization processes in thin layers of liquid widely used in chemical, biotechnology, food and other industries. The basic requirement for improving the quality of thermally labile substances is to ensure continuity of the film and a small residence time of the product on the heating surface. In rotary apparatus with falling film problem is to ensure continuity of the film, especially in the case of high intensity of evaporation. Organization upward flow in rotor-film devices allows you to create favorable conditions for the processing of thermally labile compounds.
Due to the complexity of studying hydrodynamics upward flow in a rotor-tape machine can not only describe the process of theoretical functional dependencies. Experimental studies provide an opportunity to present their results in the form of empirical equations that reflect the real picture of the process.
One of the main parameters characterizing the hydrodynamics of rising film flow is pumping and the average thickness of the film. The results of experimental studies for the height dependence of the number of revolutions of the rotor and the volume of fluid in the apparatus are based on the inhibitory influence of the wall. Also, the average film thickness is depending on the number of revolutions of the rotor and the fluid flow.
The study was carried out on a glass model of rotary-film device with a transparent wall , the height of discharge (235 mm) rotor with rigid blades, adjustable blade number (2 to 6) and the gap between the blades and the wall (0.75…2.00 mm). Experiments were carried out during isothermal upward flow of water at a temperature of 18 °C. Number of blades was 6, the distance between the blade and the wall – 2 mm. Rotor speed was changed from 30 to 100 rad/s.
It was established that the ratio of inhibitory effect increases with the amount of fluid that is in the machine, and decreases with increasing angular velocity. The thickness of the film increased with the flow and decreases with increasing angular velocity. The results are summarized relevant equations. Calculated values differ from the experimental values of less than 5 %. Reliability approximations made 0.96, indicating a sufficient reproducibility.
The results can be used for design calculations and further research rotary-film devices with a rising film.