Screw technology for air blowers

The ZS range of energy-saving screw blowers is suitable for air-blowing applications. According to Atlas Copco, screw technology on average is 30% more energy efficient compared to lobe technology and the company is convinced that the lobe technology, widely used at present, no longer meets the needs of today’s low carbon economy.

Industries and applications such as wastewater treatment, pneumatic conveying, power generation, food and beverage, pharmaceuticals, chemicals, pulp and paper, textiles, cement, and general manufacturing could benefit from energy savings through replacing the conventional lobe with screw technology. The ZS screw blower will replace the company’s entire range of ‘Roots’ type rotary lobe blowers.

In a typical biological wastewater treatment plant, the aeration blower system accounts for up to 70% of the energy usage. Today, the majority of these plants use lobe technology, a technology that has had little development since its introduction in the late 19th century. By reducing the energy usage of their aeration blower system, these plants could decrease their energy costs while operating in a more environmentally friendly manner.

“Energy consumption typically represents 80% of the life cycle costs of a blower. By introducing screw technology to our air blower range, we now offer a complete product portfolio of compressors and blowers for all applications and processes below 4 bar(e)/58 psig. Atlas Copco’s screw technology helps customers to save energy, which is a major advantage in a highly competitive marketplace,” says Chris Lybaert, President of Atlas Copco’s Oil-free Air Division.

Many industries use air blowers for their processes and will benefit from the energy efficiency of screw air blowers. Those that will have a major benefit are the municipal and industrial wastewater treatment plants, where air blowers typically represent up to 70% of the total electricity costs. Here, millions of bacteria feed on organic waste, breaking it up into carbon dioxide, nitrogen gas and water. Because the bacteria need oxygen, large amounts of air are blown in the aeration tanks.

The performance of the ZS screw blower was tested against a tri-lobe blower by the independent Technische Überwachungs-Verein (German Technical Monitoring Association, or TÜV), according to the international standard ISO 1217, edition4. It was proven that the ZS is 23.8% more energy efficient than a tri-lobe blower at 0.5 bar(e)/7 psig, and 39.7% at 0.9 bar(e)/13 psig. The efficiency of the ZS is mainly attributed to the screw technology. Other important features that provide increased efficiency and reliability are the integrated gearbox, the oil system and the innovative design that integrates all individual components into a plug-and-run solution.