Causes of Common Failures Of Lab Rotating Evaporator And How To Solve Them

The lab rotating evaporator has a built-in lifting motor, which can automatically lift the flask to a position above the heating pot when the power is cut off. Due to the centripetal force and friction between the liquid sample and the evaporating flask, the liquid sample forms a liquid film on the inner surface of the evaporating flask, and the heating area is large; the force generated by the rotation of the sample effectively suppresses the boiling of the sample.

In summary of the above features and its convenient features, the modern lab rotating evaporator can be used to quickly and gently distill most samples, even for operators with no operating experience.

Of course, we will encounter some failures more or less in the process of using the lab rotating evaporator, so let us take a look at the causes of common failures of the instrument and how to solve them.

re1-ow-t series rotating evaporator

a. The motor does not rotate
cause of the issue:
1. The indicator light (or digital display) of the electric control box is on to check whether the connection of the external plugin the electric box is loose or disconnected.
2. The indicator light (or digital display) of the electric control box does not light up.
3. Confirm that “1, 2” is not abnormal.
4. The inverter will display “O.U.” due to high-frequency interference.
5. Inverter protection function display.

1. Re-insert the plug and connect and disconnect.
2. Update the fuse or confirm that the power supply is not abnormal.
3. Update the circuit board or electric control box.
4. Connect the ground wire or change the work location.
5. Exclude according to the inverter manual P33.

b. The bath is not the heated
cause of the issue:
1. Numerous bath pots are displayed.
2. The “OUT” or “ON” green indicator light in the temperature controller is on without heating.
3. When the bath temperature is lower than the set temperature, the “OUT” or “ON” green indicator light in the temperature controller does not light up.
4. “OVER” or “000” is displayed on the temperature controller.

1. Check the power supply 220V.
2. Change the heating ring. Replace the solid-state relay or relay board.
3. Change the temperature controller.
4. Check the probe wiring or update the probe.

c. Bath pot flushing temperature
cause of the issue:
1. When the bath temperature is higher than the set temperature, the green indicator light “OUT” or “ON” in the temperature controller will not go out. (1-2℃ is normal)
2. The “OUT” or “ON” green indicator light in the temperature controller has gone out, and heating continues.
3. The digital display bath temperature is far lower than the actual bath temperature.

1. Change the temperature controller.
2. Replace solid state relay or relay board.
3. Change the probe or temperature controller.

d. The vacuum cannot be drawn
cause of the issue:
1. There is solvent in the container, which is limited by the saturated ejector pressure.
2. The capacity of the rotary vane vacuum pump is reduced.
3. The vacuum hose, the joint is loose, and the vacuum meter leaks.
4. The magnetic particle flaw detector is used for the pressure holding test. In the absence of any solvent, shut off all external butterfly valves and pipelines and hold the pressure for one minute. The pointer of the vacuum gauge should not move, indicating good air tightness, and vice versa.
5. There is debris in the discharge valve and pressure control valve.
6. The glass wool sandwich panel is damaged.

1. Vent the solvent and test with an empty bottle.
2. Change the oil (water), clean, and overhaul the rotary vane vacuum pump.
3. Detect and eliminate section by section along the vacuum pipeline.
4. ① Re-assemble, clean the glass wool sandwich panel, apply vacuum silicone grease, and tighten the flange. ②Renew the failed sealing ring.
5. Cleaning.
6. Update or repair.

The above are the common faults and solutions of the lab rotating evaporator shared for you. If you have any questions, please contact Hawach!