Final answer:
The lantern ring is designed to lubricate packing rings and cool the packing area in a pump or similar machinery, by allowing the distribution of cooling fluid or lubricant around the packing material.
Step-by-step explanation:
The purpose of a lantern ring is to serve as part of the seal protection within a pump or similar mechanical device. Its primary function is not to prevent air leakage or refrigerant leakage - these are typically the roles of other seal components. The main purposes of the lantern ring are to lubricate the packing rings and cool the packing area by providing a passage for cooling fluid or lubricant.
The lantern ring sits within the stuffing box, placed between sections of the packing material. Lubrication or cooling fluid is introduced through a hole that lines up with the lantern ring, allowing the substance to flow evenly around the packing. This ensures that the packing rings are consistently lubricated to minimize friction and wear, and it helps to dissipate heat generated by the rotating shaft.