As the core equipment for precision temperature control in laboratories, the stability of low-temperature coolant circulation pumps directly affects the accuracy of experimental data and equipment lifespan. Scientific maintenance can significantly reduce failure rates and improve refrigeration efficiency. The following provides a detailed explanation of key maintenance details from four aspects: daily inspections, periodic maintenance, seasonal adaptation, and emergency response.
1、 Daily inspection: preventive monitoring is indispensable
Before starting up each day, a basic check must be completed: ① Observe the liquid level in the storage tank to ensure that the coolant (such as ethylene glycol aqueous solution) is within the scale range. If it is insufficient, add the same type of medium. It is strictly prohibited to mix different formula liquids; ② Check for any signs of leakage at the pipeline interfaces, valves, and pump body seals, with particular attention to the risk of aging and cracking of high-pressure hoses; ③ After starting, listen to the sound of the pump body running. Abnormal vibration or noise may indicate bearing wear or impurity blockage; ④ Confirm that the displayed value of the temperature control instrument deviates from the actual temperature by ≤± 1 ℃. If it exceeds the deviation, calibrate the sensor or check the heating/cooling module. If the device is equipped with alarm function, it is necessary to test whether high and low temperature, low liquid level and other alarms are triggered normally.
2、 Periodic maintenance: in-depth maintenance according to regulations
1. Monthly maintenance: Clean the dust on the surface of the condenser fins (using a soft bristled brush and vacuum cleaner) to avoid dust accumulation that hinders heat dissipation and reduces energy efficiency; Disassemble the inlet/outlet filter screen, rinse with clean water and air dry before reinstalling to prevent particles from entering the pump body and damaging the impeller; Check whether the electrical circuit connectors are loose, especially the terminal oxidation caused by frequent start stop, and apply conductive paste for reinforcement if necessary.
2. Quarterly maintenance: Drain the old coolant and clean the system - inject clean water into the reservoir and circulate for 30 minutes. After draining, repeat twice to remove residual impurities; Replace aging O-rings and sealing gaskets (recommended every six months) to prevent leakage caused by hardening and loss of elasticity; Check the working current. If it exceeds the rated value by more than 10%, it is necessary to investigate whether the system resistance is too high or the motor load is abnormal.
3. Annual overhaul: Disassemble the pump head to check the wear of the impeller. Minor scratches can be repaired by sanding with fine sandpaper, while severe deformation requires replacement; Verify the accuracy of the temperature control sensor (compared to a standard thermometer), and recalibrate if the error exceeds ± 0.5 ℃; Conduct performance tests on the compressor, including parameters such as suction pressure and discharge temperature, to ensure efficient operation of the refrigeration system.
3、 Seasonal adaptation: coping strategies for environmental changes
In the high temperature environment of summer, it is necessary to increase the frequency of condenser cleaning (recommended once a week) and reserve more than 30cm of heat dissipation space around the equipment; When used in winter, the residual liquid in the external pipeline should be drained after shutdown to prevent freezing and cracking of the pipeline. If the ambient temperature is below -10 ℃, heat tracing insulation can be installed. For equipment that has been idle for a long time (more than one month), it is necessary to drain the coolant and blow the pipelines with nitrogen, apply rust proof oil to protect metal parts, and store them in a dry and ventilated place.
4、 Emergency response: rapid response to reduce losses
When encountering sudden malfunctions, calm handling is necessary: ① When the pump does not start, priority should be given to checking the status of the power switch, fuse, and emergency stop button; ② Sudden decrease in flow may be due to blockage of the inlet filter screen. Immediately switch to the backup filter screen and clean it; ③ In case of a liquid leakage accident, the power should be cut off immediately, and the liquid on the ground should be adsorbed with absorbent cotton. It is strictly prohibited to directly rinse electrical components with water. All maintenance operations must be recorded, including fault symptoms, handling measures, and replacement parts models, to provide reference for subsequent maintenance.