Screw compressors - range of industrial and energy-efficient models
Screw compressors are now the most commonly selected source of compressed air in industry, manufacturing and advanced service applications. Their design, based on two precision-fitted screw rotors, ensures continuous, stable operation, high efficiency and significantly lower energy consumption compared to traditional reciprocating compressors. Thanks to this screw compressors are ideal for applications requiring uninterrupted access to compressed air.
Marani offers screw compressors designed both for continuous 24/7 operation and for installations with variable air demand, where energy efficiency and precise control of operating parameters are crucial.
How do screw compressors work and why are they so effective?
Mechanism screw compressor is based on the gradual reduction of the air volume between two rotating impellers. This process takes place without pulsation, which translates into:
stable pressure,
less vibration,
quieter operation,
longer component life.
Thanks to this technology screw compressors can operate continuously without frequent interruptions, which is crucial in modern production lines.
Types of screw compressors available at Marani
Single-stage screw compressors
Single-stage screw compressors, are a universal solution for most industrial applications. They are characterised by a simple design, high reliability and a favourable price/performance ratio. They are suitable for use in production plants, workshops and pneumatic installations with a stable demand for compressed air.
Two-stage screw compressors
The two-stage compression process allows higher energy efficiency and better performance stability at higher operating pressures. Two-stage screw compressors are recommended for intensive industrial applications where maximum efficiency and minimum energy loss are important.
After twelve months of testing the two-stage compressor under harsh mining conditions, we went into production with twelve two-stage compressors DS series for a strategic client in the energy industry.
We use high-quality components in the production process:
Electric motors - Celma,
Electrical components - Simens
Soft starters - Schneider Electric,
Inverter - Danfoss Vacon,
Pneumatic components - Hoerbiger suction valves.
Two-stage screw compressors, which we offer are available in a power range of 75 to 315kW and a pressure of 7-13 bar.
Magnetic screw compressors (PM series)
One of the most technologically advanced solutions is Magnetic screw compressors - PM series. The use of a permanent magnet (PM - Permanent Magnet) motor allows for significantly higher efficiency compared to classic asynchronous motors.
Key advantages of magnetic screw compressors:
no energy loss due to engine slip,
high efficiency even at low speeds,
ideal interaction with the inverter,
a reduction in energy consumption of up to several per cent a year.
PM screw compressors are particularly suitable for variable-load installations where the compressed air demand varies over time. It is a solution for companies that focus on long-term savings and modern automation.
Inverter screw compressors - precise control and savings
The use of an inverter allows the compressor speed to be continuously adjusted depending on the current air demand. Thanks to this:
- losses due to 'idling' are eliminated,
- electricity costs are reduced,
- the service life of components is increased.
Rotary screw compressors with frequency converters work perfectly with magnetic motors to create one of the most energy-efficient compressed air systems available on the market.
Screw compressors - price and practical choice of equipment
How much do screw compressors cost?
Price screw compressor depends on a number of technological and operational factors. Due to the variety of models and configurations, the price range is wide, so it is useful to understand its basic determinants. The most important factors influencing price include:
- Motor power and efficiency (FAD) - The higher the compressed air demand, the higher the power and the higher the price. Higher horsepower compressors (e.g. above 22 kW) tend to be more expensive, but offer greater efficiency and stability in industrial installations.
- Inverter application - Inverter compressors (VSD/VS-Drive) offer infinitely variable capacity control, which saves energy but increases the cost of purchase.
- Magnetic motor (PM) - models with permanent magnet motors are characterised by higher efficiency and lower running costs, but have a higher initial price than standard versions.
- Number of compression stages - Two-stage compressors, designed for higher operating pressures, have a more complex design and higher price than their single-stage counterparts.
- Additional equipment - Dehumidifiers, industrial-grade filters, buffer tanks, control and monitoring systems affect the final price, but increase the functionality of the entire plant.
In practice, prices screw compressors start in the range of compact devices and smaller capacities (e.g. 5-7.5 kW) and increase with power, performance and equipment, reaching, in the case of large industrial machines, values appropriate to the applications of production companies or large installations.
How do you select screw compressors for your installation?
Choosing the right screw compressor is crucial for the efficient operation of the plant and the optimisation of purchase and operating costs. At Marani, we offer comprehensive support in the selection of the plant, based on process parameters and user expectations.
1. Determine compressed air requirements
The first step is to estimate:
- average and maximum air flow (FAD) in m³/min or l/min,
- required values working pressure (bar).
These data allow you to select a model with the right power and capacity. A compressor that is too small can be overloaded, while one that is too large will generate unnecessary energy costs.
2. Selection of screw compressor type
Depending on the operating conditions and the nature of the installation, consideration may be given to:
- Single-stage compressors - a versatile, economical and simple solution, ideal for stable loads.
- Two-stage compressors - better at higher pressure requirements and more intensive work.
- Inverter compressors - perfect for variable compressed air demand, where the energy benefits are significant.
- Magnetic motor compressors (PM) - a high-performance, energy-efficient solution for variable load applications.
3 Operating conditions and installation environment
When selecting, it is important to consider:
- environmental conditions (ambient temperature, humidity),
- availability of cooling (air or water),
- air purity requirements (e.g. for paint shops or food production),
- noise restrictions.
In many cases, additional components such as refrigeration dryers or filters are used to bring the compressed air to the required quality.
4 Total cost analysis (TCO)
When selecting a compressor, it is worth looking not only at the purchase price, but at the total cost of ownership:
- electricity consumption (usually the largest cost component),
- service and parts costs,
- Potential savings with an inverter or PM motor,
- expected service life of the device.
Compressors with an inverter or magnetic motor often cost more to start, but generate lower energy costs and a shorter payback time.
Why does good screw compressor selection matter?
Properly selected screw compressor:
- ensures stable and optimal operating pressure throughout the system,
- minimises the risk of overload and downtime,
- Reduces energy costs by matching performance,
- increases the life of the unit and reduces service costs.
At Marani, we support the selection process - from parameter analysis to installation, commissioning and service. This ensures that our customers receive solutions precisely tailored to the needs of their production or service facility.
Screw compressors - Guarantee and Delivery at Marani
Buying screw compressors in Marani, you get not just a device, but complete technical support:
- manufacturer's guarantee,
- professional advice on compressor selection,
- fast and safe delivery,
- commissioning and servicing possible.
Each compressor is individually selected in terms of power, capacity and the nature of the plant's operation to maximise the potential of the screw technology.
FAQ - Frequently asked questions about screw compressors
Screw compressors are compressed air machines in which the compression process is carried out by two rotating screw rotors. They provide continuous, stable operation, high efficiency and lower energy consumption compared to reciprocating compressors.
Screw compressors are used in the manufacturing industry, workshops, paint shops, automotive, food and pharmaceutical industries. They are used wherever a reliable source of compressed air for continuous operation is required.
Single-stage screw compressors compress air in a single stage and are an economical solution for standard applications. Two-stage compressors use two compression stages to achieve higher energy efficiency and better performance for higher loads.
Yes. Rotary screw compressors with inverter automatically adjust their speed to the current compressed air demand. This reduces energy consumption, eliminates losses and lowers operating costs.
Magnetic screw compressors use permanent magnet (PM) motors, which are characterised by very high efficiency. This solution ensures stable operation under varying loads and additional energy savings compared to conventional motors.
The price of a rotary screw compressor depends, among other things, on the unit's power, capacity, use of an inverter, type of motor (standard or magnetic), number of compression stages and accessories such as a dryer or control system.
The selection of a screw compressor should take into account the demand for compressed air, the nature of the operation (continuous or variable), the required pressure and the installation conditions. At Marani, we offer professional technical advice and assistance in selecting the optimal solution.