First, the start-up preparation of the -140°C ultra-low temperature chiller

1. Check whether the relevant protective measures of the ultra-low temperature chiller are in place, such as whether the tools for fire protection, protection, and leakage prevention are complete.
2. Check the power supply installation and equipment grounding of the ultra-low temperature chiller. Check whether the power supply is in place, whether the phase sequence is correct, and whether the grounding is good. Then the device is powered on.
3. Check whether the relevant valves of the ultra-low temperature chiller are open, otherwise the circulating pump will be blocked, the motor will be burned, or the pipeline pressure will be too high and the pipeline will collapse.

Second, the selection of circulating medium for -140°C ultra-low temperature chiller

1. The circulating medium of the ultra-low temperature chiller is the ethylene glycol aqueous solution selected according to the customer’s requirements. The freezing point and boiling point should be paid attention to first, so as to select the ethylene glycol aqueous solution with the appropriate concentration ratio. The stable temperature range of the ethylene glycol aqueous solution in the liquid state should include the temperature control range of the equipment or the temperature range of the controlled object, and a certain margin should be reserved.
2. When the ultra-low temperature chiller controls the jacket temperature, it is not excluded that there will be an overshoot of 0~15℃. When the equipment controls the material temperature, the circulating medium will have an overshoot of 70℃ or even higher according to the set value. If the user ignores this possibility The circulating medium will deteriorate, increase in viscosity, freeze, scale and vaporize.
3. The pipeline of the ultra-low temperature chiller at 140°C is a fully closed system, and volatilization can be ignored when closing the emptying valve during operation, and there will be losses when the medium is replaced.