MobilPower DM-Series Diesel Mobile Screw Air Compressor

Technology Platform

Mobile compressors are air-cooled. Three separate cooling circuits keep engine heat (DM) or motor heat (EM) out of the compression path: one for the airend and lubricant, one for the aftercooler, and one for the driver (engine or motor). This thermal separation ensures the compression system runs at its design temperature regardless of driver load.

DM vs EM: Which Form?

Selection advice: choose EM if a usable supply exists at the point of work; DM if not. Then select on delivered flow and discharge pressure.

• DM (diesel-driven) — for sites with no grid supply at the point of work: quarries, tunnels, pipeline right-of-ways, drilling rigs and temporary construction. A branded diesel engine drives the airend. Thermal balance to 40 °C ambient; pneumatic light-load starting; forklift pockets, tow ring and weatherproof enclosure are standard platform features. DM requires fuel logistics, exhaust aftertreatment and engine maintenance.
• EM (electric-driven) — where a usable electrical supply exists but the machine still moves: tunnels with site feeders, plant on temporary air, port quays, rail depots, or any site inside a noise or exhaust limit a diesel unit cannot meet. No on-board engine means no fuel logistics, no exhaust aftertreatment and lower noise at the machine. EM removes the engine service line (oil, filters, coolant).

Mobile Platform Features

• Towable or skid frame — towable units have a tow ring, lighting (for public-road towing) and braking; skid units have forklift pockets and lifting points.
• Weatherproof enclosure — protects the machine from rain, dust and debris. The enclosure is ventilated for cooling airflow.
• Pneumatic light-load starting (DM) — unloads the compressor before engine start, reducing starting torque and allowing the engine to start under no load.
• Three separate cooling circuits — keeps driver heat (engine or motor) out of the compression path, ensuring the airend runs at its design temperature.
• Intake filtration — standard intake filter; on multi-dust sites, a pre-separator ahead of the main intake element extends element life.

Site Conditions and Derate

Mobile compressors are sensitive to site conditions. The following factors affect whether a machine holds its rated delivery:

• Ambient temperature — design ambient is 40 °C. Above this, discharge temperature runs high; check intake blockage and cooler hot-air escape first.
• Altitude — engine output (DM) and delivered air both fall with elevation. Do not assume a sea-level nameplate flow at site elevation. Derate the machine for altitude.
• Dust — on multi-dust sites, a pre-separator ahead of the main intake element extends element life. State the actual dust condition at enquiry.
• Fuel quality (DM) — diesel engine performance and maintenance intervals depend on fuel quality. State the fuel specification at enquiry.
• Shift length — continuous duty may require a larger machine or additional cooling capacity.
• Boundary noise limit — some sites (urban construction, indoor work) have noise limits that a standard diesel unit cannot meet. EM is quieter; acoustic enclosures are available on request.

Selection Logic

MobilPower selection is based on two parameters — delivered flow and discharge pressure — not by shaft power:

The intersection of these two parameters defines the duty point. The nearest model that satisfies that point is then selected. Driver power (engine or motor) is a consequence of the flow and pressure requirement, not the starting point.

Selection advice: a tool requirement is flow at pressure. Two machines of different driver power can deliver the same flow and pressure. Power is a consequence, not a selection criterion.

1. Required flow (m³/min): determined by the sum of all simultaneous air consumers (tools, equipment) plus margin.
2. Required pressure (bar(g)): determined by the furthest endpoint’s minimum working pressure plus pipeline losses.