A compressor is a fundamental work resource on construction sites, in demolition and in tunnel construction. It supplies compressed air for tools, cleaning and cooling processes, as well as measurement and control tasks. In the context of Darda GmbH, compressed air is primarily used as supporting energy: for pre-drilling, blowing out boreholes, equipment care, and additional steps around rock and concrete splitters or concrete demolition shears. While the tools from Darda GmbH are hydraulically operated and use hydraulic power units for this, the compressor sensibly complements construction logistics when pneumatic tasks need to be carried out efficiently and safely.
Definition: What is meant by a compressor
A compressor (air compressor) draws in ambient air and compresses it to a higher pressure. The compressed air provided serves as an energy carrier for tools or processes. Key parameters are the working pressure (e.g., 7–10 bar for construction compressors), the volume flow (e.g., in L/min or m³/min as free air delivery) and the quality of the compressed air (residual moisture, oil content, particles). Unlike blowers or fans, the compressor delivers compressed air with usable pressure energy. A complete compressed-air system usually includes the compressor, aftercooler, receiver, treatment (filters, dryer, water separator), hoses and couplings, as well as suitable safety and measuring fittings.
Operating principles and compressor types
Compressors operate according to displacement or dynamic (flow) principles. Common in construction are piston and screw compressors:
Piston compressor
Compresses air in a cylinder via a reciprocating piston. Advantages: robust, good for intermittent loads, often simpler design. Suitable for small to medium air demands, e.g., for cleaning tasks, small pneumatic tools or targeted blowing out of boreholes.
Screw compressor
Two counter-rotating rotors compress continuously. Advantages: smooth delivery, high efficiency in continuous operation, lower pulsation. Often the first choice on larger construction sites when constant volume flows are required for pneumatic rock drills or multiple consumers in parallel.
Oil-lubricated or oil-free
Oil-lubricated compressors are widespread and efficient. Oil-free variants are chosen when clean, low-oil compressed air is required, for example for sensitive surface processing or when residues on concrete or natural stone surfaces are undesirable.
Mobile or stationary
Mobile construction compressors (electric or engine-driven) are typical for changing locations in concrete demolition, special demolition and rock excavation. Stationary systems are found in workshops, e.g., to supply compressed-air networks for equipment preparation.
Use in concrete demolition, special demolition and rock excavation
In projects with rock and concrete splitters, concrete demolition shears, steel shears or tank cutters, the compressor performs several tasks that support hydraulic operations. These include borehole preparation, drill dust removal, blowing off components, supplying pneumatic tools, and general equipment care.
Pre-drilling and borehole cleaning for rock and concrete splitters
Precise boreholes are crucial for stone splitting cylinders and rock and concrete splitters. Pneumatic rock drills require a reliable compressed-air supply. After drilling, cleaning is performed with a dry, sufficiently strong air stream. This removes dust and drillings and reduces friction. It facilitates the insertion of splitting wedges or cylinders and counteracts jamming. In rock excavation and tunnel construction, thorough borehole cleaning improves the reproducibility of splitting results.
Supporting tasks when using concrete demolition shears
Before gripping and breaking, loose materials can be removed with compressed air. Exposed edges can be engaged more cleanly, which is useful for strip-out and cutting. Pneumatic tools (e.g., chisels, needle scalers) can prepare the exposure of reinforcement before concrete demolition shears or steel shears are used. In sensitive special operations, dry, low-particle compressed air is advantageous to avoid contamination on cut surfaces.
Sizing: pressure, volume flow and receiver size
Sizing is based on consumer peak loads and the desired continuous operation. The key factors are:
- Working pressure: Tools commonly used on construction sites often operate at 6–10 bar. Pressure losses due to hose lengths, couplings and filters must be considered.
- Volume flow (FAD): Sum of all simultaneous consumers. Provide a safety margin to accommodate cycling and load changes.
- Receiver/reserve: A sufficiently sized compressed-air receiver reduces switching frequency, stabilizes system pressure and buffers peak loads.
- Line cross-sections: Larger hose diameters and short runs minimize pressure drop, particularly relevant for high-performance drills.
Pressure drop and ambient conditions
Altitude, temperature and humidity affect air density. In tunnels, shafts or at high elevations, delivery performance and cooling can change. Careful design prevents undersupply and unnecessary energy use.
Compressed-air treatment: dry, clean, safe
Cleaned and dried compressed air increases process reliability. Aftercoolers, water separators, dryers (e.g., refrigerant dryers) and filters reduce moisture and particles. This is important when blowing out boreholes, as moist drilling dust can clump. In cold environments, a low pressure dew point prevents icing. Oil separators and suitable filters prevent oil-bearing aerosols from reaching surfaces that will later be processed with concrete demolition shears, steel shears or tank cutters.
Compressor and hydraulic power packs working together
Hydraulic power packs provide the drive power for concrete demolition shears, rock and concrete splitters, combination shears, multi cutters and stone splitting cylinders. The compressor complements these workflows: it supplies pneumatic drilling and cleaning processes and supports logistics. Hydraulics excel with high power density and finely controllable forces at the shear or splitter; compressed air is flexible for peripheral tasks. Coordinated planning avoids idle time, reduces setup times and increases process stability.
Mobility, power supply and emissions
Mobile compressors are available with electric or combustion engines. The choice depends on the place of use, power availability, emission requirements and noise protection. Indoors and in tunnel construction, exhaust routing, ventilation and noise reduction require special attention. Sound insulation, demand-based speed control and stable placement improve working conditions.
Occupational safety and health protection
Compressed air holds high energy. Compressed air lines and couplings must be correctly sized and secured. Whip checks and secure fixings reduce risks if connections unintentionally come loose. Personal protective equipment includes hearing protection, safety glasses and dust protection. When blowing out boreholes, reduce dust generation and choose the blow-off direction safely. Pressure vessels and safety valves must be inspected regularly. Observe the manufacturer’s instructions and applicable regulations, without replacing an individual assessment of the specific case.
Operation, maintenance and condensate management
Regular maintenance preserves performance and reliability: oil level and oil quality (for oil-lubricated compressors), filter changes, belt tension, leak checks, and cleaning of coolers. Condensate must be collected and disposed of properly. Observe frost protection in cold environments. Documented maintenance improves availability and compressed-air quality—important when boreholes for rock and concrete splitters must reliably be kept free of moisture and particles.
Planning and logistics on the construction site
Clean planning integrates the compressor efficiently into the workflow with hydraulic power packs and tools:
- Position compressor, hydraulic power packs and storage areas with short routes.
- Hose management: sufficient lengths, appropriate diameters, protection against crushing and kinking.
- Capture load profiles: temporally coordinate peak loads (e.g., parallel pneumatic rock drills).
- Quality assurance: borehole cleaning as a fixed step before setting splitting wedges or using stone splitting cylinders.
- Noise control and exhaust routing as required, for example in special demolition or tunnel construction.
Typical metrics and reference values
Requirements vary depending on the task. Non-binding guide values:
- Blowing out boreholes: often 0.5–1.5 m³/min at 7–8 bar, dry and as low in particles as possible.
- Pneumatic rock drills (light to medium power): about 1–4 m³/min at 7–10 bar; large hammer drills need more.
- Small tools and cleaning: 200–800 L/min at 6–8 bar, depending on nozzle and application.
- Hose size: larger diameters (e.g., 19–25 mm) reduce pressure drop over longer distances and at high volume flows.
Checklist: selecting the compressor in the context of rock and concrete splitting works
- Capture requirements: working pressure, volume flow, duty cycle, number of parallel consumers.
- Define compressed-air quality: drying, filtration, oil content—matched to borehole cleaning and surface requirements.
- Select type: piston for intermittent, screw for continuous loads; mobile or stationary.
- Verify sizing: calculate line losses, plan receiver size and reserves.
- Consider environment: temperature, altitude, ventilation, noise control—especially in tunnel construction and indoor areas.
- Align logistics: placement, hose runs, interfaces to hydraulic power packs and tools (concrete demolition shears, rock and concrete splitters).
- Clarify maintenance and operation: accessibility, condensate management, inspection intervals, power supply.