The low-temperature cooling circulating water vacuum pump combines low-temperature refrigeration and circulating water cooling technology, and is commonly used in experimental or industrial scenarios that require high vacuum and low-temperature environments. To ensure the safe operation of equipment, extend its service life, and prevent accidents, the following safety operation requirements must be strictly followed:
1、 Preparation before operation
environment check
Ensure that the equipment is placed in a well ventilated, dry, and non corrosive gas environment, away from heat sources and flammable materials.
Check if the power supply voltage is consistent with the equipment nameplate and if the grounding wire is reliably connected.
Confirm that the circulating water system (such as cooling towers and water tanks) has started normally, and the water temperature and flow rate meet the requirements (usually 5-10 ℃ below room temperature).
Equipment inspection
Check the appearance of the vacuum pump for any damage, and ensure that the pipeline connections are tight and leak free (with a focus on inspecting the interfaces between the vacuum pump, cold trap, and vacuum system).
Confirm that the low-temperature refrigeration system (such as compressor, condenser) has no abnormal noise or vibration, and the refrigerant pressure is within the normal range.
Check the lubricating oil level (if applicable) to ensure that the oil level is between the scale markings.
safety protection
Operators are required to wear protective goggles, antifreeze gloves (low temperature parts may be below -50 ℃), and lab coats.
Prepare emergency tools: fire extinguishers, leak proof trays, first aid kits, etc.
2、 Start and Run
sequential startup
Start the circulating water system first: wait for the water temperature to stabilize before turning on the low-temperature refrigeration system to avoid damage to the equipment caused by thermal shock.
Pre cooling of low-temperature system: Start the refrigeration compressor and wait for the temperature of the cold trap to drop to the set value (such as -80 ℃) before starting the vacuum pump.
Vacuum pump start: Slowly open the intake valve to avoid motor overheating or vacuum degree fluctuations caused by sudden high load operation.
operation monitoring
Temperature monitoring: Real time observation of cold trap temperature, circulating water temperature, and refrigerant pressure to ensure that they are within the set range (such as cold trap temperature fluctuations of ≤± 2 ℃).
Vacuum monitoring: Check the vacuum degree of the system through a vacuum gauge. If there is an abnormal increase or decrease, immediately stop the machine for inspection.
Noise and vibration: Abnormal noise or vibration may indicate mechanical failure (such as bearing wear, impeller imbalance), and immediate shutdown is required for troubleshooting.
Lubricating oil condition: Regularly check the oil quality. If it becomes cloudy or contains moisture, replace it with new oil.
parameter adjustment
Avoid frequent starting and stopping of the vacuum pump, with a minimum interval of 5 minutes between each start to prevent motor overheating.
Adjust the circulating water flow rate according to process requirements to avoid excessive flow leading to increased energy consumption or insufficient flow affecting cooling effectiveness.
3、 Shutdown and maintenance
Shutdown sequence
First, close the intake valve: After stopping the pumping, let the vacuum pump continue to run for 5-10 minutes to exhaust any residual gas inside.
Stop the vacuum pump: Turn off the power, wait for the motor to completely stop, and then turn off the low-temperature refrigeration system.
Finally, stop circulating water: Ensure that the equipment is completely cooled before turning off the circulating water to prevent thermal stress from damaging the pipeline.
routine maintenance
Cleaning: Regularly clean the ice or condensate in the cold trap to prevent blockages from affecting refrigeration efficiency.
Lubrication: Regularly replace lubricating oil and clean the oil circuit according to the instructions.
Sealing inspection: Check for air leakage at the shaft seal and flange connection of the vacuum pump, and replace the seals if necessary.
Refrigeration system maintenance: Regularly check the refrigerant pressure, replenish or replace refrigerants (such as R23, R404A, etc.).
Long term discontinuation
Drain the water from the circulating water system to prevent pipeline freezing, cracking or corrosion.
Close all valves, cut off power, and cover with dust covers.
4、 Safety precautions
Antifreeze injury: Low temperature parts (such as cold traps and refrigeration pipelines) must not come into direct contact with the skin, and anti freeze gloves must be worn during operation.
Leak prevention: Regularly inspect refrigerant pipelines to prevent leaks from causing suffocation or environmental pollution (such as Freon leaks, immediate ventilation is required).
Overload prevention: Avoid long-term overload operation of the vacuum pump to prevent motor burnout or mechanical damage.
Emergency response:
In the event of a sudden power outage, immediately close the intake valve to prevent the vacuum system from backdrawing.
If a pipeline leak or equipment abnormality is found, immediately stop the machine and cut off the power supply, and contact professional personnel for repair.
Training requirements: Operators must undergo professional training, familiarize themselves with equipment principles, operating procedures, and emergency measures.
5、 Compliance and Records
Comply with the Regulations on Safety Supervision of Special Equipment and relevant industry standards, conduct regular safety inspections and keep records.
Keep equipment maintenance and repair records for easy traceability and optimization of operational processes.
By strictly adhering to the above requirements, the operational risks of low-temperature cooling circulating water vacuum pumps can be minimized to ensure safe and efficient experimentation or production.