Vacuum pump (three)

3.

The key operating specification of vacuum cryogenic freeze-drying is that the cold trap of the target object and Figure 22-22 must be cooled to the specified low temperature before the vacuum oil pump can be started under no-load conditions (open the air valve first)

The key operation specification of the vacuum heating oven is that the cold trap must be effective and reliable, and the above-mentioned vacuum oil pump should be opened and closed correctly

4.

The maintenance and maintenance of the vacuum oil pump is very important, including timely oil change, sealing of each connection, reasonable assembly of cold traps and absorption towers, and correct startup and shutdown

5.

(1) Use the vacuum oil pump as a water circulating vacuum pump to pump low boiling point or acid-base substances, and the absorption devices are not installed in place or at all

(2) Idling or pumping air for a long time

(3) Turn off the pump first, and then vent to the atmosphere, so that the oil pump sucks backwards

(4) Too many leakage points, improper construction and assembly, and air leakage

(5) Use for a long time overnight

(6) Place in an environment filled with corrosive gas

(7) Extensive operation

(8) The parts are loose

(9) Do not wipe at ordinary times

Figure 22-23 Oil pump accident

6.

(1) Don't expect to install cold traps to achieve full absorption.
For strong acid and alkali compounds, acid and alkali adsorption devices must also be installed
.

(2) It cannot be directly connected to a rotary evaporator, and cannot pump low-boiling substances (bp≤120℃)
.

(3) When connecting the vacuum tube, be careful not to reverse the inlet and outlet of the cold trap, otherwise the solvent in the cold trap may be inhaled into the oil pump
.

(4) It is not allowed to start the oil pump with gloves soaked in solvent
.

(5) Do not empty pump for a long time to avoid premature wear of the oil pump
.

(6) Pay attention to the color of the oil.
When it turns black or milky white, report for repair and change the oil in time
.
If the oil pump sucks back, the oil should be changed
.

(7) For a good vacuum pump, after pumping to a higher vacuum, the sound is faint and crisp.
When it is found that the motor is not running or the motor is buzzing, shut it down in time and unplug the power plug, otherwise the motor will become hot and catch fire.
Dangerous
.

(8) After using the instrument, unplug the power supply and clean the exterior
.

Related Links: Vacuum Pump (2)