What is the main purpose of a filter-drier in a refrigeration system?

The primary function of a filter-drier in a refrigeration system is to remove moisture and contaminants from the refrigerant. Moisture and particulate materials can cause significant problems, such as corrosion, ice formation, and clogging of components, which can lead to system failures. The filter-drier typically contains desiccant materials that absorb moisture, along with a filter that captures solid particles, ensuring the refrigerant remains clean and dry as it circulates through the system. By maintaining a proper refrigerant state, the filter-drier plays a crucial role in the overall reliability and efficiency of the refrigeration system. Other options such as raising refrigerant pressure, enhancing cooling efficiency, or reducing system noise do not pertain to the main function of the filter-drier, which is specifically focused on the quality of the refrigerant.