Real time monitoring for the efficient use of industrial pneumatic applications

Abstract

Manufacturing companies are becoming increasingly aware of the financial and environmental penalties linked with inefficient compressed air systems. Traditional methodologies of identifying and maintaining compressed air inefficiencies have proved to be ineffective. Therefore, current market trends are shifting towards implementing smart monitoring devices that make use of Industry 4.0 to communicate information in real time. A significant portion of analysed case studies and market options implemented monitoring devices that analysed data from the supply side of the system. According to the literature, demand side inefficiencies account for 50-70% of the total compressed air improvement opportunities. However, only one market option was identified which monitored the demand parameters and it made use of highly proprietary equipment that drove up implementation costs. Therefore, a real time demand side data monitoring system was designed to scientifically answer the research questions that were established. The experimental procedures showed that three different parameters had to be monitored in order to identify inefficiencies at the demand side. These included system pressure, system flow rate and actuation rate. The latter parameter was an innovative way of analysing different inefficiencies through the digital time stamps of solid state switches installed with each compressed air actuator. Through these digital data time stamps, the actuation rate was monitored in a highly accurate manner by using a technique that was not encountered in the literature survey. The results showed that with an introduction of a large 1.61mm leak, the actuation rate of an actuator decreased marginally by 0.82% while the actuation rate of a faster secondary cylinder decreased by 1.57%. This concluded that a leak within an automation system impacted the actuation rate of all actuators within that system. The change in actuation rate was interpreted through Bernoulli’s principles which was related to a decrease in static pressure that was caused by an increase in flow rate due to a 1.61mm leak. Moreover, by correlating the changes that were measured in terms of system pressure, compressed air flow rate and actuation rate, inefficiencies such as leakages, faulty actuators and an increase in system pressure were identified at the demand side with the use of standard equipment and sensors.