Oil-free screw compressors

How to choose an oil-free screw compressor

Choosing a specific model is not easy; it is a complex task that requires analysis of several factors at once. Both current needs and potential opportunities for future scaling are taken into account. The choice depends primarily on the purpose of the machine and the requirements placed on it:

• To estimate performance, add up the consumption of the finished product by all tools operating simultaneously, add 20-30% for reserve for optimal compressor operation; also take into account the coefficient of simultaneous connection (0.6 ‒ 0.8);
• determination of the working pressure of equipment;
• What degree of air purity is required (classes from 0-1 to 2-3 depending on the purpose and industry of consumption)?
• What type of oil-free technology: wet or dry lubrication?
• planned operating mode: for continuous operation, the unit can be used without a receiver; for periodic operation, an air tank is required;
• The required energy efficiency to reduce operating costs; pay attention to the specific power rating of the unit.
• assessment of the noise level that is suitable for a specific application (noise-absorbing covers are used for confined spaces);
• What are the operating conditions: temperature, humidity, dustiness in the room, presence of aggressive substances in the atmosphere, requirements for machine mobility.

Important point: choice of manufacturer, its reputation, provision of service support, availability of spare parts.

Description of oil-free twin-screw main unit

Precise phasing and effective compression of the gas medium are possible thanks to the coordinated operation of two screw rotors. The drive rotor is driven by the motor, while the driven rotor is synchronized via a gear transmission. The rotors do not come into contact with each other; there is a gap between them. Compressor oil is used in this design to lubricate the gear transmission and bearings, and is prevented from entering the compression chamber by a mechanical seal on the main unit shaft.

Main components, advantages

• oil-free twin-screw unit, compact with a long service life;
• energy-efficient electric motor, brushless, with frequency control, increased efficiency;
• protective coupling, needed to protect the screw pair from overloads;
• frequency converter, smoothly regulating speed, ensuring fast response;
• cooling and filtration system for lowering the temperature of gas and oil and effectively removing impurities, dust, and moisture from the gas environment;
• programmable logic controller with an extended range of performance adjustment, the ability to connect to a cloud monitoring system;
• oil supply and filtration unit, in which the pump ensures a stable oil supply, and a dual-line dirt-trapping filter switches lines without stopping the compressor;
• separator, for two-stage separation and subsequent drying with minimal pressure loss.

Вопросы, ответы

• Which compressor should you choose, oil-lubricated or oil-free?

Oil-lubricated compressor units are more suitable for high-performance production facilities that do not require a clean air environment. Oil-free compressors are in demand in industries (medical, pharmaceutical, food) where absolutely clean air without oil impurities is required.

• What are the advantages of using oil-free compressors?

Advantages of oil-free units:

• providing absolutely clean air, free of oil impurities;
• reduction in operating costs for frequent maintenance, filtration costs, and oil replacement;
• use in industries where air purity is paramount;
• compensation for the relatively high initial cost through subsequent long-term savings;
• exclusion of waste oil disposal.
• What is the service life of an oil-free compressor?

The unit can operate for 10 to 15 years depending on the intensity of use, compliance with operating regulations, design features, and timely maintenance.

• Используется ли винтовой компрессор без ресивера?

Suitable for continuous consumption and stable supply. The installed air tank smooths out pressure fluctuations, reduces the frequency of switching on/off, removes moisture, extends service life, and increases system efficiency.