Safety, patience, and meticulousness are the key to operating a laboratory distillation tower. strictly adhere toThe basic principles of "installation, leak detection, slow heating, monitoring, and sequential shutdown". The key points to note when using a laboratory distillation tower can be divided into several stages:

1 Preparation and inspection before operation

This is the most critical step in ensuring safety and cannot be omitted.

Equipment installation and air tightness inspection:

Correctly assemble：Strictly assemble the tower body, condenser, receiving bottle, vacuum joint, etc. correctly according to the instructions or training received. Each interface should be aligned and subjected to uniform force, especially for glass components. When tightening the clamps, the force should be moderate to prevent cracking due to uneven stress.

Airtightness test (crucial)Distillation, especially vacuum distillation, requires system sealing.

Close all valves, start the vacuum pump, and evacuate the system to a certain degree of vacuum.

Close the valve between the system and the vacuum pump, and observe whether the vacuum level remains stable in a short period of time. If the pressure rises rapidly, it indicates that there is a leakage point, and it is necessary to use soap water and other methods to investigate one by one (interfaces, valves, plugs, etc.) until the problem is solved. Heating operations are strictly prohibited if the airtightness is not qualified.

Material addition and system smoothness:

Material propertiesClarify the properties of the material to be separated, such as boiling point, thermal sensitivity, oxidation, corrosiveness, flammability, and explosiveness. This is related to the choice of heating method, temperature, and vacuum degree.

add ingredientsAdd materials through the feeding port, taking care not to exceed the safe capacity of the tower kettleTo prevent liquid flushing during boiling.

Add fillersIf it is a packed tower, ensure that the packing is clean and evenly filled to avoid dry areas.

Check for patencyEnsure that all channels such as the overhead distillate pipeline and vacuum pipeline are unobstructed.

II During the operation process

1、Heating control:

Slowly heating upIt is strictly prohibited to suddenly apply full power heating! The heating power should be slowly and gradually increased. Excessive heating can cause liquid flooding, where rising steam inside the tower carries a large amount of liquid to the top of the tower, disrupting the distillation process and even causing accidents.

Choose a suitable heat sourceAccording to the document, there are heating methods such as electric heating sleeves and thermal oil baths. Ensure that the upper temperature limit and temperature control accuracy of the heat source meet the requirements. For thermosensitive materials, it is necessary to strictly control the temperature of the tower kettle.

Establish and maintain balance:

Full refluxAfter heating starts, do not remove the product yet, let all the condensed liquid at the top of the tower reflux back into the tower (full reflux operation). Continue for a period of time to bring the gas and liquid phases of each tray or packing section in the tower to equilibrium (temperature readings tend to stabilize). This is a prerequisite for achieving good separation efficiency.

Adjust reflux ratioAfter establishing balance, set the reflux ratio as needed. The larger the reflux ratio, the better the separation effect, but the slower the output rate. Optimization should be carried out based on product purity and efficiency requirements.

2、Vacuum operation:

If vacuum distillation is carried out, the order must be followed: first evacuate, then heat. The order of shutdown is reversed: first stop heating, wait for the material to cool to a safe temperature, then turn off the vacuum pump, and finally slowly introduce air into the system. Reversing the order can cause boiling liquids to suddenly boil violently due to external pressure, which is extremely dangerous!

Install a cold trap between the vacuum pump and the front stage to capture low boiling point solvents and protect the vacuum pump.

3、Real time monitoring:

Closely observe the temperature readings of the tower kettle, tower body, and tower top, and record the pressure values.

Observe the gas-liquid contact inside the tower, promptly detect and handle it“Liquid flooding”or“leakage”Abnormal phenomena such as liquid flooding, where the liquid inside the tower is held up by steam and cannot be removed, resulting in increased pressure fluctuations.

It is strictly prohibited to leave the post, and someone must be present to guard during the operation.

III After the operation

Shutdown in sequence:

Stop heating->Waiting for natural cooling of the system->Release the vacuum (slowly release)->Turn off the cooling water.

Be sure to wait for the temperature of the tower kettle to drop below the flash point or boiling point of the material before disassembling.

System cleaning and maintenance:

After the equipment cools down, disassemble and clean it in a timely manner. Prevent residual materials from corroding equipment or affecting the next experiment.

For stainless steel towers, it is important to choose appropriate cleaning agents to avoid corrosion. For glass towers, handle them gently and store them properly.

4 Special precautions

Customized featuresThe document clearly states that“The above parameters are not used as ordering standards”This means that your device may have its specific configuration. Be sure to familiarize yourself with the specific operation manual of your device and the mutually confirmed plan.

Material compatibilityConfirm the contact material between your material and equipment (high borosilicate glass)3.3 orSUS304Is stainless steel compatible to avoid corrosion. For example, concentrated hot phosphoric acid, strong alkali, etc. can corrode glass.

Electrical safetyPay attention to the power specifications（220V/380V）Ensure good grounding to prevent electric shock.

Heat medium selectionIf using thermal oil or high-temperature circulators, ensure that the thermal stability temperature of the heat medium is higher than the operating temperature to prevent decomposition, coking, and even combustion of the heat medium.