How to choose a suitable rotary evaporator for distillation and purification experiments?

Rotary evaporators are devices used in laboratories for efficient and gentle distillation of solvents evaporated from samples. Rotary evaporation is often used to conveniently separate "low boiling point" solvents such as butane or ethanol from compounds that are solid at room temperature and pressure. However, careful application of reduced pressure can remove the solvent from the sample without degrading the product. Reducing the pressure speeds up the process by lowering the boiling point of the components in the boiling flask, allowing for the lowest possible temperature distillation. The rotating 10,000ml boiling flask sprays liquid sideways, forcing more liquid to be exposed to surface area and effectively transferring more heat. The combination of reduced pressure and efficient heat transfer makes this distillation unit ideal for rapid industrial separations.

How Rotary Evaporators Work

The distillation flask for a rotary evaporator can be a pear-shaped or round-bottomed flask with a standard ground port, connected to a Vacuum Pump through a high-reflux serpentine condenser, and the other opening of the reflux condenser is a mill with a receiving flask. mouth. Connect to receive evaporated organic solvents. There is a three-way piston between the condenser tube and the decompression pump.

When the system is connected to atmosphere, the distillation flask and receiver flask can be removed and the solvent transferred. When the system is connected to a pressure reducing pump, the system should be downsized. state of stress. When in use, first reduce the pressure, and then start the motor to rotate the distillation bottle. Finally, stop the machine first, then pass the atmosphere to prevent the decanter from falling during the rotation. As a heat source for distillation, the rotary evaporator can be used in combination with circulating water multifunctional Vacuum Pumps, diaphragm Vacuum Pumps, low-temperature circulating (vacuum) pumps, circulating coolers, constant temperature circulators, and low-temperature coolant Circulating Chillers to form a system device.

When operating a rotary evaporator, you may often encounter the following problems:

1. A low acceptance rate is good when it evaporates.

2. The Vacuum Pump is corroded.

3. Harmful gas escapes.

4. Sudden solvent collision.

A higher than normal vacuum in the rotary evaporator system is a possible cause. If the vacuum is too high, the temperature of the solvent vapor will be too low, so it cannot be effectively collected. The vacuum needs to be released, but if the vacuum is too low, other problems can occur.

How to avoid these problems?

It is important to choose a suitable rotary evaporator, the following professional advice on how to choose the correct rotary evaporator, you need to know:

1. What is the important performance of the rotary evaporator?

Air impermeability is the first important performance of the rotary evaporator, which directly affects the normal operation of the rotary evaporator

operation and service life. The quality of breathability depends on the supplier's design criteria, manufacturing

The measurement standards are "actual vacuum degree" and "vacuum holding time".

2. What is the difference between a glass lift and a bathtub lift?

The lifting of the bath is safer, and the glass parts matched with the rotary evaporator are not easy to be damaged, and there is no need to

Lock it after hoisting is complete. Glass hoisting is mainly suitable for rotating flasks of fixed size, the hoisting height is fixed, and it needs to be locked after the hoisting is completed.

3. Which type is better for #29 and #24 evaporating flasks?

Both ISO#29 and ISO#24 are laboratory standards. ISO#29 has high strength and is easy to clean. It is more suitable for imported rotary evaporators, and it is also beneficial for you to choose flask moving devices.

4. In which case, the coagulation effect is better?

The temperature of tap water varies with seasons and temperatures. Higher in summer, the recovery efficiency of the condenser is low, and tap water will cause the condenser to change color and scale.

You can choose between two lab solutions:

1) Solution: Equip a suitable low temperature cooling circulation pump, please pay attention to "refrigerating capacity", "minimum temperature", "circulation joint", "circulation volume" and "circulation pressure" when selecting. We offer cryogenic equipment specialization in rotary evaporators.

2) For laboratory rotary evaporators, the cold trap may be ice cooled.

5. How to improve the service life of the rotary evaporator?

1) Please operate according to the instruction manual of the well-known rotary evaporator.

2) After the research is completed, please clean the rotary evaporator in time.

3) The surface of the rotary evaporator should be kept clean.

When using a rotary evaporator, take care to handle and wash, dry or dry glass parts before loading. Vacuum grease is applied to each grinding port, face seal and joint before installation. Water needs to be added before the heating box of the rotary evaporator is powered on, and dry boiling is not allowed. The interface of each connector is sealed. Sealing ring, whether the sealing surface is effective. Whether there is vacuum grease between the main shaft and the sealing ring. Whether the Vacuum Pump and its hose are leaking. Whether the glass parts are cracked, cracked or damaged.