Investigation of the Optimal Vacuum Depth Created by an Ejector Depending on the Value of the Supply Pressure

Introduction . Vacuum ejectors operating on the Venturi principle are used in various industries and are essential pneumatic devices. An important characteristic of a vacuum ejector is the vacuum depth it creates, where the maximum vacuum value is obtained in a certain range of supply pressure. Failure to comply with the supply pressure affects the performance of the ejector itself and automated vacuum systems in general. One of the options for solving this problem is to establish the recommended range of supply pressure in a fairly narrow pressure range, at which a guaranteed value of vacuum depth is reached without using the maximum capabilities of the ejector. At the same time, the technical literature does not provide the values ​​of the dependence of the vacuum depth on the supply pressure over the entire range of ejector operation, which the authors would like to draw attention to in this work. The research objective was to conduct experimental studies on establishing the true values ​​of the maximum vacuum depth depending on the magnitude of the ejector input pressure. Materials and Methods. To conduct experimental research, a special stand was designed, manufactured and used, which allowed for the study of vacuum ejectors operating on the basis of the Venturi principle. This stand provided setting the exact vacuum value depending on the input supply pressure for ejectors with a nozzle diameter from 0.1 to 4.0 mm, which completely covered the entire range of ejectors used in real sectors of the economy. Vacuum ejectors of the VEB, VEBL, VED and VEDL families manufactured by Camozzi were investigated in the range of the inlet supply pressure of the ejector from 2.0 to 6.5 bar. The true values of the vacuum depth were determined experimentally depending on the value of the input supply pressure for each ejector, as well as the maximum values of the vacuum depth reached by each ejector at the corresponding value of the input supply pressure. Results . It was experimentally proved that the recommended values of the input supply pressure given in the catalogs of ejector manufacturers did not always correspond to the true values. It was shown that the character of the obtained graphs also differed. In this regard, it was necessary to adjust the value of the input supply pressure to reach the maximum vacuum depth for each type of ejector. Discussion and Conclusion . The results of the conducted experimental studies allow for a rational choice of vacuum ejectors depending on the required technological tasks. This will ensure the operability of automated vacuum systems and the performance of the ejector itself. The research results can be used by all ejector manufacturers to adjust their basic catalogs and relevant recommendations for the use of these products.