1. Minor maintenance on freeze-dryer

Maintenance and troubleshooting of the refrigeration system, vacuum system, and heating system leaks and malfunctions, checking if all indicator instruments are in normal condition.

② Replace damaged or malfunctioning parts, inspect and adjust the tension of the drive belts between the motor and various compressors, and vacuum pumps.

Check and tighten all connecting bolts, inspect the oil levels of the refrigeration compressor, vacuum pump, mechanical supercharger pump, and circulating oil tank.

④ Check and calibrate the zero points of the recording instruments and vacuum gauges. After three minor repairs, if system components continue to frequently malfunction, disassembly, repair, or replacement of damaged parts and reassembly are required.

2. Maintenance of Freeze-Drying Machine

① Including minor repairs, inspecting electrical control devices, replacing wearing parts, and checking and repairing oil pumps.

② Start the refrigeration compressor, inspect the refrigeration system to ensure normal high and low pressure, and that the refrigeration temperature corresponds to the low pressure. Check if the low pressure (valve must be closed) meets the requirements; if refrigerant is insufficient, add refrigerant.

Inspect vacuum pumps, mechanical supercharger pumps, and sealing conditions, eliminate leakage points and associated faults, sequentially check the vacuum pump units, condensers, and boil-off boxes to ensure they meet vacuum requirements, and eliminate leakage points.

Check the mechanical supercharger oil for emulsification and deterioration; replace as necessary.

3. Major Maintenance of Freeze-Drying Machine

① Including mid-term repairs.

② Inspected the electrical system, removed various instruments (including recorders) for calibration, checked each contactor and relay for proper operation, assessed the extent of contact damage, and replaced any damaged electrical components.

Disassemble and clean the oil pump, inspect the pump blades and other components, and test the oil quality, replacing as necessary.

Disassemble and clean the refrigeration compressor, inspect the condition of the valves, vapor rings, cylinders, crankshafts, and other worn parts; replace any parts exceeding the limit, change the lubricating oil, and replace the desiccant in the desiccant filter.

⑤Disassemble and clean vacuum pumps and mechanical superchargers, inspect the wear of components such as bearings, piston ring bushes, gears, and replace any parts exceeding limits; replace shaft seals.

⑥ Inspect all valves, replace the sealing rubber gaskets, and for accumulated oil in cooling system components like pipe-type evaporators, use nitrogen gas at a pressure of 1 MPa to clean thoroughly.

Repaired equipment foundations, and insulated, anti-corrosion treated, and painted.