This article provides a detailed overview of the circulating water vacuum pump to help laboratory personnel better understand and operate the equipment.
I. Operating Procedures for Circulating Water Vacuum Pumps
Proper operation of the circulating water vacuum pump is essential to ensure the smooth conduct of experiments and the normal functioning of the equipment. The detailed operating steps are as follows:
(1) Equipment Inspection
Open the water tank lid and fill the tank with distilled water; the water level should be slightly below the overflow nozzle to prevent water spillage or motor damage caused by a lack of water.
Close the lid, connect the equipment to the power supply, and attach a rigid rubber hose to the vacuum inlet.
Turn on the power switch, block the end of the rubber hose with your finger, and observe the vacuum gauge reading. If the gauge reaches -0.1 MPa, the equipment is operating normally and is ready for subsequent experiments.
(2) Vacuum Filtration Operation
Connect the rigid rubber hose to the side arm of the vacuum filtration flask; wet the filter paper with water to ensure it adheres tightly to the funnel surface; turn on the circulating water vacuum pump and observe whether the system pressure drops (if the pressure does not drop, check the airtightness of the setup); once the pressure drop is confirmed, proceed with the filtration; after the experiment, disconnect the rigid rubber hose from the filtration flask before turning off the pump.
(3) Vacuum Distillation Operation
Connect the rigid rubber hose to the side arm of the vacuum receiving adapter; turn on the circulating water vacuum pump to initiate evacuation and reduce pressure; once the vacuum gauge reading drops and stabilizes, begin heating the system to perform the distillation; after distillation is complete, disconnect the rigid rubber hose from the vacuum receiving adapter, stop heating, and finally turn off the circulating water vacuum pump.
II. Precautions for Circulating Water Vacuum Pumps
1. Evacuate before heating: During reduced-pressure distillation experiments, the system must be evacuated to reduce pressure before heating begins; this prevents accidents caused by sudden pressure changes.
2. Check airtightness: Before the experiment, verify the airtightness of the vacuum filtration or distillation setup to ensure there are no leaks, thereby guaranteeing experimental results.
3. Proper shutdown procedure: After the experiment, disconnect the rigid rubber tubing from the system or open the safety flask stopcock before turning off the circulating water vacuum pump; this prevents equipment damage caused by sudden pressure changes.
4. Water level control: Check the water level in the reservoir before use, ensuring it is slightly below the overflow nozzle. Excessively high or low water levels can damage the motor and impair the equipment's normal operation.
III. Maintenance and Care of Circulating Water Vacuum Pumps
Regular maintenance and care are essential to extend the service life of the circulating water vacuum pump. Below are some maintenance recommendations:
1. Regularly change the water in the reservoir: Ensure water cleanliness to prevent impurities from clogging pipes or affecting equipment performance.
2. Check pipe connections: Periodically inspect the airtightness of the rigid rubber tubing and other connecting parts; replace them promptly if damaged.
3. Clean the equipment surface: Keep the equipment surface clean to prevent corrosion caused by dust or chemical substances.
4. Storage environment: Store the equipment in a dry, well-ventilated area, avoiding direct sunlight and environments with high temperatures or humidity.