Freeze drier capable of self-recirculating and regenerating of cold trap

Abstract

The invention discloses a freeze drier capable of self-recirculating and regenerating of a cold trap. The freeze drier comprises a refrigerating system, a vacuum freezing and drying system and a lithium chloride liquid regenerative system, wherein the a freezing and drying tank is internally provided with a shelf, and the shelf is internally provided with an evaporation heat transferring coil and an electric heating strip; the cold trap is externally provided with a cooling coil, and the cold trap is filled with a lithium chloride solution; a single-level compression refrigerating system is adopted as the refrigerating system; and a freezing and drying tank vacuumizing opening, a vacuum diaphragm valve, the cold trap, an electromagnetic air-release valve and a vacuum pump are connected sequentially; and a cold trap solution outlet, a lithium chloride solution pump, a lithium chloride solution regenerator dilute solution channel, a regenerator, a lithium chloride solution regenerator concentrated solution channel, a throttling valve and a cold trap solution are connected sequentially. The invention has the following beneficial effects: in the cold trap, a concentrated lithium chloride solution is adopted for absorbing vapor without an over-low refrigeration temperature, and the ordinary single-level compression refrigerating circulation can be reached; and the lithium chloride solution can be regenerated continuously, and the production efficiency can be improved without a frost removing step and an ice-melting step.

Description

technical field [0001] The invention relates to a freeze dryer, in particular to a freeze dryer with a self-circulating regeneration of a cold trap. Background technique [0002] Freeze-drying (freeze-drying) technology refers to freezing the material at low temperature, and then sublimating most of the water in the material by vacuuming and heating, so as to keep the material in a dry state and achieve the purpose of long-term storage at room temperature. The basic components of a freeze dryer include a refrigeration system, a vacuum system, a heating and drying system, and a measurement and control system. There are two main functions of the refrigeration system, one is to provide cooling capacity for the shelf during the freezing process, and the other is to provide cooling capacity for the cold trap, and condense the sublimated water vapor in the material into ice during drying. Freeze dryers are now widely used in freeze-dried storage of various biological samples, inc...

AI Technical Summary

Problems solved by technology

[0003] The freeze dryers currently used on a large scale in the industry need the cold trap (water vapor condenser) to reach a low temperature (-60°C to -80°C) to ensure that there is enough water between the partition of the freeze-drying box and the cold trap Vapor pressure difference acts as the driving force, causing most of the water vapor to condense into ice at the cold trap; this low temperature is mostly achieved by using liquid nitrogen or compression refrigeration, and there are also small experimental freeze dryers that use semiconductor refrigeration, but it is difficult to apply for large-scale industrial production

In the usual single-stage vapor compression refrigeration cycle, its low-temperature evaporation temperature can maintain good efficiency at -30°C to -50°C; while lower evaporation temperatures require two-stage vapor compression refrigeration or self-cascading refrigeration cycles , greatly increasing the complexity of the refrigeration system

In addition, whether liquid nitrogen or compressed refrigeration is used, a large amount of energy will be consumed, and the possible leakage of refrigerants (such as Freon, etc.) will also have a destructive effect on the ozone in the atmosphere. does not match

[0004] At the same time, because the traditional freeze dryer uses cold traps to condense most of the water vapor into ice, it requires additional shutdown steps to defrost or melt ice in the cold traps, resulting in discontinuous production; The method of counting and switching systems to ensure the continuity of the freeze-drying process will also greatly increase the complexity of the freeze-drying machine

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