Gravity Air Compressor Enables Energy-Efficient Compressed Air Generation

Industrial compressed air generation is facing a potential paradigm shift. A new type of gravity air compressor uses only water and gravitational forces to compress air, achieving energy savings of 37 per cent compared to conventional systems. This innovative technology operates with virtually no heat generation, whereas conventional compressors generate considerable heat during rapid compression, which wastes energy.

The principle is based on a fundamentally different approach to air compression. Instead of metallic compression elements such as screws, pistons or rotors, the system uses water as the compression element. This liquid is not subject to mechanical wear and tear and enables complete sealing without the leaks between fixed components that are common in conventional compressors.

The technology addresses a central problem faced by many industrial operations: fluctuating compressed air consumption due to inconsistent processes and production sequences.

While conventional systems falter in the low power range and often cannot be regulated below 30 per cent of their capacity, the gravity air compressor enables continuous modulation between zero and 100 per cent. This flexibility leads to improved control over air flow and power consumption.

Functional Principle of a Water-Based Compression

At the heart of the technology are spirally arranged PE pipes with a continuously decreasing internal diameter. These spirals are aligned at a 45-degree angle and organised in parallel. The compression process begins in an upper tank that is half-filled with water. Air and water are alternately fed into the downward-leading spirals.

During rotation, gravity pushes both water and air downwards. The water acts as a movable piston. The conical shape of the spiral pipes continuously reduces the available volume per revolution. Gravity creates height differences in the standing water pistons, building up higher pressure with each spiral revolution.

A key advantage is the continuous cooling provided by the water throughout the entire compression process. The water pistons serve as multiple integrated cooling elements that stabilise the temperature throughout the compression process. This keeps the temperature almost constant, resulting in high efficiency and significantly reducing the need for downstream cooling and drying.

At the end of the spirals, the compressed air and water are separated in a bottom tank inclined at 45 degrees. The air outlet is located above the water surface to ensure that only air escapes. The water is returned to the upper tank via an outlet below the water surface, using its pressure to convert it into potential energy that is reused in the system. The compressed air enters the next compression stage for further pressure increase. This multi-stage process is repeated until the desired total pressure is reached, with the water circulating within each compression stage.

Technical Advantages and Operating Characteristics

The design operates at speeds below 15 revolutions per minute – a dramatic difference from screw compressors, some of which operate at up to 25,000 revolutions per minute. These low speeds are possible because water acts as a sealing element and completely isolates the air. The compressor can even come to a complete standstill while maintaining air pressure without any loss – a feature that would be unrealistic with metallic compression elements.

The oil-free technology eliminates the need for oil cleaning and the associated maintenance work. With only one rotating component – the spiral mechanism itself – the system is characterised by its mechanical simplicity. The entire rotating mechanism operates passively and requires no additional water supply after the initial water filling. The system only requires air as a supply and emits compressed air exclusively.

The air intake of a gravity air compressor is located about 20 metres above the ground, where the particle density is significantly lower than at ground level. An integrated filter also prevents contaminants from entering the system. The robust PE pipe construction is not subject to extreme manufacturing tolerances, as the natural elasticity of water makes precision manufacturing unnecessary.

The possibility of outdoor installation is particularly advantageous for production facilities. The weather-resistant construction frees up valuable space in production halls for other applications and can increase compressor capacity without additional investment in building infrastructure. The long service life results from the combination of few moving parts, low operating speeds and the absence of wear due to friction between metal components.

Source / photo (screenshot): Enairon (Sweden)