Short Path Distillation Units and Parts for Sale
Short path ditilation unit is one of the common methods for separating purifiable organic compounds. Short-path distillation devices are especially suitable for those substances that have been thermally decomposed, oxidized or polymerized before reaching the boiling point during atmospheric distillation. Rotary evaporator is a simple short-path distillation device.
Short path distillation instructions:
The boiling point of a liquid refers to the temperature at which its saturated vapor pressure is equal to the external pressure. Simply put, it is the temperature at which the liquid boils at a standard atmospheric pressure. Therefore, the boiling point of a liquid is not fixed and will vary with the external pressure. Vacuuming to reduce the pressure in the system can reduce the boiling point of the liquid, which is the theoretical basis for the operation of short-path distillation.
20L short path distillation vacuum pump
Short path distillation unit:
It is mainly composed of four parts: distillation main body, gas extraction, safety protection and pressure measurement.
1. Distillation part: It consists of distillation flask, Kjeldahl distillation head, capillary tube, thermometer, condenser tube, collector, etc.
Kjeldahl distillation head: It can reduce the possibility of splashing into the condenser due to liquid bumping;
Capillary: As the gasification center, it can make the distillation stable and avoid the phenomenon of bumping out due to overheating of the liquid. The capillary mouth is about 1 to 2mm away from the bottom of the bottle. In order to control the air intake of the capillary, a soft rubber tube can be placed on the top of the capillary glass tube, and a thin wire is inserted into the rubber tube and clamped with a screw clamp.
Collector: Usually two or three round flasks are connected with a multi-tail liquid pipe. When receiving different fractions, just turn the liquid pipe. Do not use pressure-resistant flat-bottom bottles (such as conical flasks, etc.) to prevent inward explosion.
2. Pumping part: The commonly used pressure reducing pumps are water pump and oil pump.
3. Safety protection part: generally there is a safety bottle. If an oil pump is used, there must also be a cold trap and a drying tower to avoid the low boiling point solvent entering the oil pump and reducing the vacuum efficiency of the pump, especially acid and water vapor, so before the oil pump short-distance distillation All low-boiling liquids and water, as well as acid and alkaline gases must be distilled off under normal pressure or reduced pressure by a water pump.
4. Pressure measuring part: The pressure measuring gauge is used, but with the development of technology, electronic pressure measuring elements are now used.
Schematic diagram of short-path distillation parts
D-SPD-20L short path distillation
Operation method:
1. First check whether the system is leaking, the method is: close the capillary, depressurize until the pressure is stable, clamp the rubber tube connecting the system, and observe whether the mercury column of the pressure gauge changes, no change means no leak, and a change means that Air leak. In order to make the system airtight, all the interface parts of the grinding instrument must be well lubricated with vacuum grease.
2. After checking that the instrument is not leaking, add the liquid to be steamed, the amount should not exceed half of the distillation bottle, close the piston on the safety bottle, start the oil pump, and adjust the amount of air introduced by the capillary, so that a series of small bubbles can emerge. .
3. When the pressure is stable, start heating. After the liquid boils, you should pay attention to controlling the temperature and observe the change of the boiling point.
4. When the boiling point is stable, turn the multi-tailed liquid pipe to receive the fraction, and the distillation speed is preferably 0.5 to 1 drop/S.
5. After the distillation is over, remove the heat source, slowly unscrew the screw clamp of the rubber tube clamped on the capillary, and then slowly open the piston on the safety bottle after the distillation bottle is slightly cooled (if it is opened too fast, the mercury column may break through pressure gauge), balance the internal and external pressure, and finally turn off the air pump.
The above is the details of the short path distillation unit. If you have needs, you can contact Zhengzhou Keda Machinery Equipment Co., Ltd. For decades, Zhengzhou Keda Machinery Equipment Co., Ltd. has been committed to the production and manufacture of laboratory instruments and pipe fittings. If you want to know about our products, or are interested in purchasing our instruments, please contact us, we will be happy to help you.
