[Patent Abstract]
This invention discloses an external cold trap for the dilution refrigerator, specifically relating to the fields of cryogenic engineering. It includes a liquid nitrogen tank with a purification chamber inside. The purification chamber, from top to bottom, comprises a separation unit, a purification unit, and a pre-cooling unit. A sealed top cover is provided on the top of the purification chamber, with an inlet pipe, an outlet pipe, and a maintenance channel. This invention increases the heat exchange efficiency of the airflow and reduces the cooling time by adding a pre-cooling unit and a separation unit to the lower and upper parts of the purification unit, respectively, made of activated carbon, thereby improving purification efficiency. Simultaneously, the separation unit and copper mesh filter form a self-purification device, avoiding the self-contamination effect of the cold trap. This ensures long-term stable operation of the throttling process and the stability of the dilution refrigerator during repeated long-term operation, significantly extending the maintenance cycle of the dilution refrigerator. This has a very positive significance for the practical application of the dilution refrigerators.
