Atlas Copco ZS 4 VSD Oil-Free Screw Blower, 37-90 kW

Class 0 oil-free screw blowers from 37 to 90 kW

The Atlas Copco ZS 4 (VSD(+)) is an oil-free rotary screw blower for low-pressure process air, available from 37 to 90 kW at fixed speed or with variable speed drive. It is aimed at wastewater aeration, pneumatic conveying, fermentation, combustion air, fluidisation, truck unloading and flotation, and the leaflet cites cement, food, chemical, textile, beverage and pharmaceutical industries as well as wastewater treatment. The IE4/IE5 motor platform and the smart pressure split design are central: a low-pressure element below 800 mbar suits aeration, while an advanced high-pressure element covers conveying and other industrial duties, with pressures up to 1.5 bar.

Technical specifications

Imperial ratings and weights

The leaflet also gives horsepower ratings and weights in pounds for each size.

Design and installation

The leaflet describes a durable screw element and purpose-designed drivetrain, refined acoustics with internal damping that bring noise down to 75 dB(A), a compact footprint that allows side-by-side installation, and easy access to serviceable components. The unit is plug-and-play, which keeps installation and service time short. Both fixed speed and VSD versions with several pressure options are offered, so the same family covers a steady aeration load or one that varies with the process.

Benefits stated by the manufacturer

Atlas Copco groups the benefits of the ZS 4 into three areas. For total cost of ownership, the high-efficiency IE4/IE5 motor reduces energy consumption and the plug-and-play design minimises installation, service and downtime. For reliability, robust components are built for a long service life in harsh industrial conditions, with reduced mechanical stress and fewer failure points. For performance, the leaflet cites stable airflow even under constant load, output optimised across varying pressure demands, and Class 0 oil-free compression for clean air.

The 5-year warranty on the screw element is an Atlas Copco warranty. The leaflet makes it valid only when original Atlas Copco spare parts are used and all service is performed by Atlas Copco certified service personnel. The motor platform is described as minimising energy loss across the entire pressure range, and the drivetrain is purpose-designed for long service life and dependable uptime.

Selecting a ZS 4

Select by required airflow and pressure at the site intake temperature, and decide between the low-pressure element for aeration and the high-pressure element for conveying. Confirm voltage, frequency, ambient temperature, altitude and the choice between fixed speed and VSD. Seven Star LLC, an independent supplier in Muscat, quotes the exact variant. The leaflet is attached and other machines are under Compressors.

How the Atlas Copco ZS 4 VSD blower works

Two screw rotors turn inside a casing without touching each other. Air is drawn in, trapped between the rotors and squeezed as it moves along them. Because no oil enters the air end, the air is Class 0 oil-free. A variable speed drive changes the motor speed, so the blower can match its output to the demand of the process. This avoids running at full speed when less air is needed.

Where the ZS 4 VSD is used

• Wastewater aeration
• Pneumatic conveying
• Fermentation
• Combustion air and fluidisation
• Truck unloading and flotation

Selection checklist for the ZS 4 VSD

• Motor power from 37 to 90 kW
• Fixed speed or variable speed version
• Airflow in m3/h
• Pressure up to 1.5 bar
• Low-pressure or high-pressure element
• Noise limit of the site
• Footprint and side-by-side space
• Industry and air quality needs

Installation, commissioning and maintenance notes for the ZS 4 VSD

Place the blower on a flat base in a ventilated room with room around it for service access. Connect the pipe without strain and the power supply with the right cable size. Check the rotation direction and run the unit up slowly. Follow the maker’s service schedule and use original spare parts for service.

Requesting a quotation for the Atlas Copco ZS 4 VSD

Please send the airflow, the pressure, the motor power and the quantity. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

ZS 4 VSD power sizes

The sizes are 37, 45, 55, 75 and 90 kW, which equal 50, 60, 74, 101 and 121 hp.

ZS 4 VSD airflow

The maximum free air delivery runs from 2,182 m3/h on the 37 kW size to 3,217 m3/h on the 90 kW size.

ZS 4 VSD pressure

The maximum pressure is 1,500 mbar, which is 21.7 psi.

ZS 4 VSD noise

The noise level is 75 dB(A).

ZS 4 VSD weight

The weight runs from 1480 kg for the 37 kW size to 1776 kg for the 90 kW size.

ZS 4 VSD dimensions

The blower measures 1490 by 1740 by 1250 mm.

ZS 4 VSD motor

The blower uses an IE4/IE5 motor platform.

Blower records for the ZS 4 VSD

Record the running hours, the pressure and the date of each service.

Choosing the right ZS 4 VSD element

Choose the low-pressure element for aeration below 800 mbar and the high-pressure element for conveying.

ZS 4 VSD design

The leaflet describes a durable screw element, a purpose-designed drivetrain and internal damping that lowers the noise.

ZS 4 VSD installation space

The compact footprint allows side-by-side installation, and the serviceable parts are easy to reach.

ZS 4 VSD plug-and-play

The unit is delivered ready to connect, which keeps installation and service time short.