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.