Oil-Free Scroll Vacuum Pump

What is the Oil-Free Scroll Vacuum Pump?

An oil-free scroll vacuum pump uses interleaved spiral scrolls to reach about 0.1 to 0.01 mbar without oil. It suits clean processes and sensitive analyses where hydrocarbon contamination is unacceptable in any quantity.

Overview

The scroll pump uses two interleaved spiral scrolls, one fixed and one orbiting, that trap crescent-shaped gas pockets and move them to the center exhaust. Because there are no sliding vanes or sealing oil, the compressed volume is dry and clean. Ultimate pressure is about 0.1 to 0.01 mbar and pumping speeds range from 30 to 300 liters per minute, matching a rotary vane pump for medium vacuum. Scroll pumps run quietly with low vibration, need only tip-seal replacement every one to three years, and tolerate water vapor well when a gas ballast is provided. They are used for mass spectrometers, electron microscopes as backing pumps, freeze dryers, gloveboxes and semiconductor tools. The clean exhaust and absence of oil make them preferred where backstreaming would harm samples, detectors or cleanrooms.

How does it work?

Vacuum pumps remove gas molecules to lower pressure in a sealed volume. Positive-displacement types, including rotary vane, diaphragm, scroll and roots pumps, trap a volume of gas and push it out. Momentum-transfer pumps, including turbomolecular and diffusion pumps, accelerate molecules toward an exhaust that a backing pump removes. Water-ring and ejector pumps use a liquid or a jet to entrain and carry gas away. Performance is described by ultimate or base pressure and by pumping speed, which is measured in liters per second or cubic meters per hour. Real performance also depends on the gas load, on outgassing from chamber walls, and on the conductance of the connecting piping. Vapor handling, corrosion resistance and cleanliness determine which pump suits a given process, and pumps are often combined in stages to cover a wide pressure range.

What are the key features?

• Oil-free operation with clean, dry exhaust
• Ultimate pressure of about 0.1–0.01 mbar
• Pumping speeds of 30–300 L/min
• Quiet, low-vibration orbiting scroll design
• Tip-seal replacement every 1–3 years
• Good water vapor tolerance with gas ballast

What are the technical specifications?

A typical oil-free scroll vacuum pump configuration offers ultimate pressure of 0.1–0.01 mbar, pumping speed of 30–300 L/min, number of stages of 1 or 2, motor power of 0.2–1.1 kW, gas ballast of Optional and tip seal life of 1–3 years. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Oil-Free Scroll Vacuum Pump is used in mass spectrometer backing, electron microscope backing, freeze drying, glovebox and clean processes and semiconductor tool vacuum. Across the wider Vacuum Pumps class, laboratories also deploy it for chamber evacuation for drying and degassing, rotary evaporation and distillation and freeze drying and centrifugal concentration.

Which standards and certifications apply?

Relevant standards and methods include IEC 61010-1, IEC 61326-1, ISO 21360, ISO 27893, ISO 20485 and GB 4793.1. Certification candidates for this model are CE, RoHS and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Protect the pump from the process with a cold trap, foreline trap or filter, and vent to atmosphere before switching off a high-vacuum pump. Change oil and check seals on schedule for oil-sealed pumps, and inspect scroll tips and diaphragms for dry pumps. Keep tubing as short and wide as possible to preserve conductance, and use the correct flange type and vacuum grease sparingly. Monitor pressure with gauges appropriate to the range, such as Pirani, capacitance or ion gauges. Follow IEC 61010-1 for electrical safety and local pressure equipment rules. For oil-free or clean processes, confirm that the pump cannot backstream oil or particles. Record base pressure and pump-down curves during commissioning and at each service so that degradation is detected early.

How do I select the right Oil-Free Scroll Vacuum Pump?

Choose a scroll pump when oil-free cleanliness, quiet operation and low maintenance matter, even at higher purchase cost. For robust, low-cost medium vacuum, a rotary vane pump is sufficient. In the RFQ, state ultimate pressure, speed, water vapor load and connection type.

How does it compare with other Vacuum Pumps variants?

Work from the required working pressure, the gas composition and the volume to be evacuated. For rough vacuum in filtration and drying, a diaphragm or single-stage rotary vane pump is sufficient. For medium vacuum in rotary evaporation and coating, a two-stage rotary vane or scroll pump is appropriate. For high and ultra-high vacuum in electron optics, surface analysis and semiconductor work, a turbomolecular pump with a suitable backing pump is needed. Consider whether the gas is condensable, corrosive or particle-laden, and add traps, filters and corrosion-resistant materials as required. Size pumping speed from the chamber volume, the target pressure and the acceptable pump-down time, remembering that conductance limits real speed. Decide between oil-sealed and dry designs based on contamination risk, and specify gauges, valves and controllers as part of the system.