Dry Vacuum Pumps: Advantages, Structure, Operation, and Applications
Dry vacuum pumps are currently among the most widely used devices to create vacuum in vacuum technology and scientific research in laboratories due to several advantages compared to other types of vacuum pumps. What are these advantages? Do you know about dry vacuum pumps? If not, let’s explore them together!
Advantages of Dry Vacuum Pumps Over Other Types
Dry vacuum pumps do not use any working fluid in the working chamber, so the vacuum created will be highly pure, free of impurities, making it ideal for research and experiments in fields like nuclear physics, solid-state physics, nanotechnology, and more.
In processes where reactive chemical elements or harmful substances are present, not using working fluids helps the dry vacuum pump to be applied in the research and production of semiconductors or chemicals.
When using a dry vacuum pump in production research, operators do not need to monitor the working fluid, allowing the pump to be integrated into production lines or systems that were previously challenging to use with oil-seal or water-ring vacuum pumps.
Structure of Dry Vacuum Pumps
In terms of general structure, dry vacuum pumps are designed similarly to oil-seal vacuum pumps, with a rotor placed eccentrically with the cylinder. The vanes are attached to grooves in the rotor and can slide freely in and out of the cylinder walls. As the rotor rotates, the vanes slide out and maintain constant contact with the cylinder walls due to centrifugal force.
The biggest difference compared to oil-seal vacuum pumps is that dry vacuum pumps do not use oil in the working chamber for lubrication or to seal gaps that cause air leakage. Therefore, all components are precisely manufactured and calibrated to minimize the gap. The vanes of dry vacuum pumps are typically made from composite graphite material, which has excellent heat resistance, high mechanical strength, and low friction to reduce wear in the working chamber.
The vacuum pumping cycle is clearly illustrated above. As the rotor rotates, the volume of space between the vanes changes. When the vane moves from step 1 to step 2, the increase in volume at the narrow section creates the vacuum. As the space between the vanes reduces in the cycle, the trapped air between the vanes gets compressed, as seen in steps 2 and 3. Finally, between steps 3 and 4, the compressed air is expelled through the exhaust.
Advantages and Disadvantages of Dry Vacuum Pumps
Advantages:
- The first advantage is that there is no oil in the exhaust air, making them more environmentally friendly.
- There is no need to monitor the oil level or properties in the working chamber or periodically add oil.
- In terms of cost, dry vacuum pumps are generally cheaper than oil-seal vacuum pumps because they do not have an integrated oil circulation system.
Disadvantages:
- The primary disadvantage of dry vacuum pumps is that the vacuum level they can achieve is relatively moderate, ranging from 90 to 400 mbar, depending on the model, while oil-seal pumps can achieve much higher pressure levels.
- Additionally, the lifespan of composite graphite vanes is not very long, often not exceeding 10,000 hours, while the vanes in oil-seal pumps can last up to 50,000 hours. If the composite graphite vanes are not replaced in time after prolonged use, they can wear down, causing graphite dust to enter the air.
- Manufacturing high-quality dry vacuum pumps remains quite challenging and complex. Currently, dry vacuum pumps are mostly produced in Europe, with a few small models being made in the U.S., China, and Taiwan.
One popular dry vacuum pump model in Vietnam is the Rocker vacuum pump, made in Taiwan. The Rocker dry vacuum pump is an oil-free, non-polluting pump that does not require frequent oil changes or maintenance. It comes with an integrated thermal overload relay and automatic shut-off function when the pump gets too hot, restarting once the temperature lowers. The compact pump is equipped with a carrying handle, and the pump base has rubber pads to minimize vibration during operation. The Rocker vacuum pump is primarily used in biological and chemical laboratories, air sampling, vacuum filtration, and more. Depending on the intended application, desired vacuum level, and rotational speed, consumers can choose from various Rocker products with different technical specifications, such as Rocker 800 vacuum pump, Rocker 300 vacuum pump, Rocker 400 vacuum pump, and 12V Rocker 300DC vacuum pump.
CTSTEC is an authorized distributor offering high-quality Rocker vacuum pumps in Vietnam at competitive prices. Please contact us for the best advice regarding your selection.
