Choose the right Vacuum Forming Pump
When choosing vacuum pump, there are many choices for you to choose the most suitable pump for your application. There are different types of vacuum pumps, which can provide different displacement and limit vacuum.
There are four main types of freeze-drying (freeze-drying), evaporation and concentration in the laboratory.
Type of Vacuum Pump: Rotary Blade of Rotary Vane Pump
Traditional rotary vane (RV) vacuum pumps are often used because they have lower upfront costs, are smaller than other types, and can be used in a variety of applications. RV pumps use oil to ensure seal, lubricate working parts and remove heat to cool the rotor.
Any solvent not captured or recovered before entering the RV vacuum pump will condense in the pump oil and damage the pump interior. This is necessary when RV pumps are used to collect vapor from the upstream of the pumps. Condensers or traps are usually used to collect these vapors and protect pumps.
Another drawback of RV pumps is the need to replace oil, which is an expensive process. It is recommended that the oil in these pumps be checked regularly and used every 3000 hours.
The life of vacuum pump depends on the maintenance of oil. Although some systems can automatically change oil, it still wastes time when the pump is no longer used for maintenance.
Rotating vane vacuum pump achieves extremely high vacuum level and high displacement capacity. This makes them ideal for freeze-drying applications. RV pumps are especially suitable for water samples and solvents with high boiling point. Their vapor can be easily captured before reaching the pump.
Type of vacuum pump: diaphragm pump aperture
Diaphragm vacuum pump is a dry pump. It operates with impulse motion and opens and closes valves to move air. This design eliminates the need for oil. Valves are usually made of polytetrafluoroethylene (PTFE), which enables the pump to resist corrosive substances and is not easily damaged by steam.
Although they can have higher upfront costs, they do not use any oil, so the cost of operation and maintenance is significantly lower than that of pumps requiring oil. Diaphragm pumps can handle high viscous liquids and can be used with various samples, but their applications are limited to those requiring higher vacuum limits.
The ultimate vacuum level of these pumps is not very deep, and the displacement capacity is much lower than other types of vacuum pumps.
Diaphragm pump is one of the most chemical corrosion resistant pumps. Therefore, almost any type of sample, even a combination of solvents and acids, can be used with these pumps, making it a good choice for evaporation and concentration.
Because the vacuum depth is not enough, the diaphragm pump can not be used for freeze-drying.
Type of Vacuum Pump: Combination/Mixing Pump Combination (Mixing)
Combination vacuum pump, also known as hybrid vacuum pump, has rotating vanes and diaphragm pumps in the same vacuum pump. In combined pumps, the diaphragm pump keeps RV pump oil under negative pressure to reduce or eliminate steam passing through it and condensate in the oil. This design makes the oil cleaner and less frequent to replace - 10 times longer than RV pumps.
Therefore, although there may be higher upfront costs than RV pumps, the operating costs are reduced due to the need for less oil replacement and less time to replace oil. The limit vacuum level and displacement capacity of the combined pump are similar to those of the RV pump. Because diaphragm pumps have been incorporated into the design, they are better than RV pumps in acid and solvent treatment.
Combination pumps are recommended for freeze-drying of corrosive or volatile samples, as they can be used with acid samples and samples containing irritant chemicals such as TFA, acetonitrile, HBe and nitric acid.
Type of vacuum pump: scroll pump (dry vacuum pump) rolling
The scroll vacuum pump is a dry pump, which compresses air and steam with two scrolls and moves them to the exhaust port. Although they can have higher upfront costs, their lifetime running costs are much lower because they do not require oil and require little maintenance.
It is recommended that the reel be replaced every 40,000 hours. By eliminating oil, hydrocarbon-free design means that these pumps are also environmentally friendly. Vortex pumps handle water vapor better than most types of pumps and produce significantly less noise during operation.
Since the reel is made of metal, only samples with acid content less than 20% are recommended for chemical or corrosion resistant models. Compared with the diaphragm pump, the scroll pump can reach a deeper limit vacuum level and has a higher displacement capacity.
It is recommended that scroll pumps be used for freeze-drying because they can be used with water and solvent samples, including acetonitrile. They can also be used for enrichment applications, but cost tradeoffs can make another type of pump more attractive.
No matter what type of pump you use, one of the most important things about vacuum pumps is that whatever you pump out will appear! Even with filters, you need to take other precautions when the sample contains potentially dangerous materials. When using dangerous samples, it is necessary to ventilate them to the fume hood.
Provide a variety of vacuum pump options and many vacuum pump accessories, including the new scroll pump. If you are not sure which vacuum pump is most suitable for your application, our application experts are ready to help you.