Analysis of periodic inspection and maintenance methods of pilot freeze dryer

　　Analysis of periodic inspection and maintenance methods of pilot freeze dryer
　　1, Minor repair
　　①Repair and eliminate the leakage and failure of the refrigeration system, vacuum system and heating system, and check whether the indicators of the pilot freeze dryer are in a normal state;
　　② Replace damaged or poorly working parts, check and adjust the tightness of the drive belt between the motor and each compressor and vacuum pump;
　　③Check, tighten the connecting bolts of each part, check the oil level of the refrigeration compressor, vacuum pump, mechanical booster pump, and circulating oil tank;
　　④ Check and verify the zero position of the recording instrument and vacuum gauge. After three minor repairs, if the system components still fail frequently, they need to be disassembled, repaired or replaced with damaged parts and reassembled.
　　2, Intermediate
　　① Including minor repairs, inspection of electrical control devices, replacement of vulnerable parts, inspection and repair of oil pumps;
　　② Start the refrigeration compressor and repair the refrigeration system so that the high pressure and low pressure are normal, and the refrigeration temperature corresponds to the low pressure. Check whether the low pressure (the suction shut-off valve needs to be closed) can meet the requirements. If the refrigerant is insufficient, add refrigerant;
　　③Check the working and sealing conditions of the vacuum pump, mechanical booster pump, eliminate leak points and troubleshoot, and check step by step whether the pump set, condenser, and drying box meet the vacuum requirements to eliminate leak points;
　　④ Check whether the mechanical booster pump oil is emulsified and deteriorated, and replace it if necessary.
　　3. Overhaul
　　①Including the intermediate training content.
　　② Check the electrical system, remove each instrument (including the recorder) for calibration, check whether each contactor and relay can work normally, check the degree of contact damage, and replace damaged electrical components;
　　③ Disassemble and wash the oil pump, repair the oil pump blades and other parts, check the oil quality, and replace it as appropriate;
　　④Remove and clean the refrigeration compressor, check the wear of the valve disc, steam ring, cylinder, crankshaft, etc., replace the over-limit parts, replace the lubricant, and replace the desiccant in the drying filter;
　　⑤Remove the vacuum pump and mechanical booster pump, check the wear of bearings, piston ring bushings, gears and other parts, replace the over-limit parts, and replace the shaft seal;
　　⑥ Check the valves, replace the sealing rubber gaskets, such as the pipeline evaporator of the refrigeration system, and use a nitrogen pressure of 1 MPa to blow them away;
　　⑦Repair equipment foundation, and keep heat preservation, anti-corrosion and painting.