Final answer:
A lantern ring is designed to distribute lubrication and cool the packing within a mechanical device, which can help maintain the integrity of the seal and indirectly minimize leakage.
Step-by-step explanation:
The purpose of a lantern ring is to serve as a part of a seal or packing within a pump or other similar mechanical devices. Its main function is to distribute lubricating fluid and to help cool the packing material to prevent overheating due to friction. While the lantern ring can indirectly help with minimizing leakage by keeping the packing in optimal condition, it does not directly prevent air or refrigerant leakage as its primary purpose.