Compressed air technology/system

Compressed air technology/system is a mainstay in many areas of demolition works and rock cutting/processing. On construction sites, in tunnels, and during selective deconstruction, it enables energy-efficient, robust, and often low-spark workflows. In combination with the hydraulically operated tools from Darda GmbH—such as concrete demolition shear, hydraulic rock and concrete splitters, or rock wedge splitter—compressed air assumes a central role: from driving pneumatic rock drill for boreholes to supplying air-driven hydraulic pump and the low-dust cleaning of drill holes. This interaction of pneumatics and hydraulics allows controlled, low-vibration, and precise interventions in concrete and rock—especially where vibrations, emissions, or space are limited.

Definition: What is meant by compressed air technology/system

Compressed air technology/system encompasses the generation, storage, conditioning, distribution, and application of compressed air as an energy carrier. A compressor compresses ambient air to a defined operating pressure (typically 6–10 bar, higher for special applications), a vessel stores the energy, conditioning stages (aftercooler, dryer, filters, oil mist lubricator) ensure the desired air quality, and a piping or hose system conveys the compressed air with minimal losses to the consumer. Important parameters include volume flow (e.g., l/min or m³/min), the effective working pressure, and air quality (e.g., residual oil, particles, pressure dew point). In contrast to hydraulics, air is compressible, which gives tools a softer response, stores energy, and facilitates return motions. In practice, compressed air is valued as safe, robust, and universally available—especially in dusty, damp, or temperature-critical environments.

Compressed air in concrete demolition, rock excavation, and tunnel construction

In concert with Darda GmbH’s hydraulic tools, compressed air enables decisive process steps. In rock excavation and tunnel construction, boreholes for rock wedge splitter or hydraulic splitter (wedge) are predominantly produced with pneumatic rock drill. Required hole diameters and depths depend on the geometry of the splitting tools and the material at hand. In concrete demolition and deconstruction, compressed air also supports blowing out the drill holes (a low-dust, adhesion-promoting surface for splitting wedges) and pinpoint exposure of reinforcing steel before concrete demolition shear are deployed. In interior areas or zones with electrical restrictions, air-driven hydraulic power units are used to supply concrete demolition shear, hydraulic splitter (wedge), multi cutters, steel shear, or tank cutters hydraulically without introducing electrical ignition sources. In all these scenarios, the proper configuration of working pressure, volume flow, hose cross-section, and air quality is essential for performance, safety, and service life of the components used.

Structure and components of a compressed air system

A practical compressed air system for demolition and rock work consists of coordinated modules that are robust, mobile, and easy to maintain. Typical components are:

• Compressor: Piston or screw compressor, mobile (construction-site unit) or stationary; selection based on required volume flow and working pressure.
• Aftercooler and water separator: Reduce air temperature and remove condensed water to improve air quality.
• Compressed air dryers: Refrigeration dryers for moderate dew points, adsorption dryers for low pressure dew points (e.g., in cold weather or tunnel operation).
• Filter stages: Pre-filters, fine filters, and optionally activated carbon filters to reduce particles, water, and oil mist—as required by the tool.
• Receiver tank: Smooths load peaks, stabilizes pressure, and reduces compressor cycling.
• Pressure control and point-of-use conditioning: Pressure regulators, gauges, and, if applicable, oil mist lubricators for oil-lubricated tools.
• Hoses and couplings: Sufficient cross-section, appropriate pressure rating, secure couplings with safety wire/whip-check.
• Measuring and monitoring: Flow meters, pressure sensors, dew point indication, leakage control.

Sizing: pressure, volume flow, and hose management

Sizing starts with the demand of the consumers. Pneumatic rock drill, air flushing, and air-driven hydraulic power pack each have characteristic volume-flow and pressure requirements. A compressor is selected so that under real conditions (altitude, temperature, hose length) the necessary working pressure is still available at the point of use. Pressure losses arise primarily from undersized hose cross-sections and long runs. A practical approach:

1. Identify consumers: Determine the highest simultaneous air demand and working pressure.
2. Plan reserve: Allow 15–30% reserve for aging, filter contamination, and unforeseen loads.
3. Line design: Use short, large-diameter hoses; avoid unnecessary couplings and tight bends.
4. Measure pressure at the tool: Place a gauge as close to the consumer as possible to verify actual working pressure.

Practical note: For drilling operations in preparation for rock wedge splitter or hydraulic splitter (wedge), pay close attention to volume flow. A stable volume flow improves impact energy and drilling progress—while reducing tool wear and heat buildup.

Compressed air quality: drying, filtration, and oil management

Condensate and drying

Moist air reduces the performance of pneumatic tools and promotes corrosion. In cold environments, condensate can freeze in lines or valves. A pressure dew point suited to the environment (e.g., via refrigeration or adsorption dryers) and automatic condensate drains ensure readiness—especially in tunnel construction and during winter operations.

Filtration and particles

Fine filters protect valves, sealing systems, and impact mechanisms from abrasive particles. During dust-intensive demolition works, filter maintenance should be frequent. A differential-pressure-monitored filter system helps to change elements on time and keep pressure losses low.

Oil-free versus oil-lubricated supply

Some pneumatic tools require a minimal amount of lubricant oil (oil mist lubricator), others are designed for oil-free air. The specifications of the respective tool are decisive. For air-driven hydraulic power pack supplying concrete demolition shear or multi cutters, clean, dry air is important to keep control valves and air motors reliable.

Energy efficiency and economical operation

• Minimize leaks: Even small leaks add up to significant losses. Regular checks (e.g., ultrasound) pay off.
• Demand-based control: Variable-speed compressors or staged control reduce idle time and energy use.
• Optimize pressure level: Every additional bar increases energy demand; run only as high as needed for rock drill, air flushing, or power pack.
• Heat recovery: Compressor waste heat can be used for heating or hot water where operationally sensible.
• Improve line routing: Large cross-sections and short runs lower pressure losses and thus compressor work.

Occupational safety and security

Compressed air is safe but demands careful handling. Hose whipping is prevented by safety cables; couplings must be fully locked and secured against accidental release. Personal protective equipment (hearing protection, safety glasses, gloves) is standard for drilling and blow-off work. Dust is to be minimized, e.g., by extraction and wet cleaning. Pressure vessels and compressors are to be inspected and maintained regularly; requirements may vary by country and site. In potentially explosive atmospheres (ATEX zone), only suitable equipment and procedures are to be used; a tailored hazard analysis remains indispensable.

Interfaces to hydraulic power pack and tools

Many Darda GmbH tools are hydraulic but can be supplied via air-driven hydraulic power pack. This combination is useful indoors, in shafts, or where electrical power is limited. Important points:

• Sufficient air volume flow: Dimension the air side so the power pack provides the required hydraulic flows and pressures for concrete demolition shear, hydraulic splitter (wedge), multi cutters, steel shear, or tank cutters.
• Control quality: Cleanly regulated air pressure increases the constancy of hydraulic performance and thus the reproducibility of work progress.
• Conditioning: Dry, clean air increases the service life of air-side motors and valves in the power pack.

Practical guide for deconstruction and tunnel construction sites

1. Determine demand: Which processes run in parallel (rock drill, blow-off, air-driven power pack)? Determine peak load.
2. Select compressor: Size volume flow and pressure with 15–30% reserve; consider environmental influences (altitude, temperature, dust).
3. Plan conditioning: Select appropriate dryer, define filter stages, ensure condensate removal.
4. Design hose system: Large cross-section, short runs, secure couplings, whip-checks, and protection against mechanical damage.
5. Set measuring points: Provide gauge/dew point indication at critical locations (near rock drill or power pack).
6. Organize work areas: Dust management (extraction/wetting), safe hose routing, avoid trip and crush points.
7. Commissioning: Leak test, pressure test at minimum and maximum flow, verify tool function under load.
8. Monitor operation: Regularly check filter differential pressure, dew point, temperature, and noise level; eliminate leaks immediately.
9. Maintenance and documentation: Intervals by operating hours; service compressor oil, filters, dryer media, and safety valves on schedule.

Typical error sources and how to avoid them

• Hoses with too small cross-sections: Lead to high pressure losses and weak tool performance—use larger diameters.
• Insufficient drying: Condensate causes corrosion and icing—use suitable dryers and drains.
• Excessive network pressure: Increases energy costs without benefit—set pressure to the required value.
• Contaminated filters: Increase pressure losses—monitor differential pressure, replace on time.
• Missing safeguards: No whip-checks on couplings—increases injury risk if a line fails.
• Uncontrolled blow-off: Dust turbulence and impaired visibility—use extraction/binders, blow off deliberately and sparingly.

Practical values and units

For system design, working pressure (bar) and volume flow (l/min or m³/min) are decisive. The effective pressure at the tool determines the impact energy of rock drill and the performance of air-driven hydraulic power pack. The pressure dew point describes drying depth—the lower it is, the lower the risk of condensate or icing. For assessing cost-effectiveness, specific energy demand (e.g., kWh/m³) matters; leaks and unnecessarily high network pressure are particularly detrimental here.

Maintenance, condensate management, and environmental aspects

Regular maintenance preserves performance and safety. This includes oil and filter changes on the compressor, dryer service, testing safety valves, and cleaning or replacing intake filters. Condensate must be handled properly; depending on its contents (oil, particles), suitable treatment solutions are to be used. Compliance with applicable regulations and manufacturer guidance supports legally compliant and sustainable operation.

Relation to concrete demolition shear and hydraulic splitter (wedge)

In practice, the direct benefit of compressed air technology/system arises from smooth interaction with Darda GmbH’s hydraulic tools. Concrete demolition shear reach their potential when the hydraulic power pack are stably supplied on the air side. Hydraulic splitter (wedge) and rock wedge splitter work efficiently when boreholes are created quickly and to size with consistent pneumatic energy. A well-planned compressed air system accelerates this process chain—from drilling to cleaning through to powerful, controlled splitting or cutting.