Development of a prototype for the recovery of R134a from the mixture of RPCs detectors

<!--HTML-->The aim of this thesis work is to analyse in detail all the steps involved in the creation of a working prototype that can recover R134a gas from an azeotropic mixture. The various chapters are arranged in such a way as to follow the process and provide the information necessary for understanding the various operations. <br>The first chapter aims to give an explanation of why it is necessary to recover R134a, but especially where and why it is used. The discussion will take a top-down approach, starting with CERN and the LHC, and then moving on to the experiment that will house the prototype, CMS. Then the detectors using this type of mixture and more generally the gas system for muons detectors will be introduced. An overview such as this, and in particular going into detail about the gas system for muons detectors, is essential to understand the context, and since the R134a recovery system will be part of this complicated process, it is good to be fully aware of what can affect the system in question and vice versa. <br>Around 2018, a prototype had been developed to perform this task, but without success. Over time, following many unsuccessful tests, the problem was identified: R134a and the isobutane iC4H10 form an azeotropic mixture. Chapter 2 looks chronologically at the evolution of the prototype before arriving at the need to develop a new one. The configuration of this first prototype has been changed twice. This chapter will show the tests carried out on the last two configurations, carried out after the discovery of the azeotropic mixture. The study of these tests will make it possible to immediately identify the parameters that most influence the system and set as a goal for the subsequent prototype the optimisation of these to increase the efficiency of the system and the purity of the recovered gas.<br>Finally, the last two chapters will deal with the construction of the new prototype. They have been divided into two sections as they conceptually represent two phases that can be conducted in parallel. One deals with the steps relating to the design of the prototype, through the use of P&IDs and 3D drawings, and the construction of the prototype, while the other deals with the development of the logic and programming processes required for the prototype to function. From a chronological point of view, the steps to follow are the design of the prototype and with it the development of 2D and 3D models, followed by the development of the process logic and its transformation into code readable by the future PLC. This is followed by the construction phase of the prototype and the analysis of its criticalities, as shown in the paragraph on leak tests, and finally everything related to the electrical and electronic components, which includes the construction of the rack that will house the PLC.<br>In conclusion, therefore, the aim of the thesis work is to follow the steps necessary for the realisation of a working prototype for the recovery of R134a gas. The studies and analyses carried out on the first version provide a better understanding of the fundamental parameters and solve the problems related to it. In addition, the need to manage a variable flow led to the design of the prototype, which will be analysed in detail below.