SM Series Oil-Injected Screw Air Compressors

In underground mining, compressed air is the main power source for pneumatic picks, rock drills, pneumatic chargers and similar equipment. The traditional approach is to build a compressor station on the surface and pipe the air down — the longer the line, the greater the pressure and volume losses, and the harder leaks at joints are to track down, so the pressure and flow actually reaching the point of use are often well below what was intended.

The Fusheng SM series mining explosion-proof screw air compressor is designed for precisely these hazardous gas environments. Built around safety, reliability and stability, it can be deployed underground to supply air on site, removing the pressure and volume losses that come with sending air down from the surface. Working pressure is 0.7~1.25MPa, air delivery 4.6~42m³/min and power 37~250kW, with both air-cooled and water-cooled lines available.

Why Underground Air Should Be Supplied On Site

Working faces can lie hundreds of metres below ground, and the points of use are scattered and keep moving as mining progresses. Sending compressed air down from the surface means a long run of pipe, and pipe diameter, elbows and joints all introduce pressure loss, while ageing pipework and failed seals add continuous leakage. The result: the surface compressor works hard while the underground equipment never gets enough.

Put the compressor underground and the unit goes wherever the point of use is; with a short run of pipe, pressure loss and leakage fall naturally and the supply pressure and flow become steadier. The precondition, of course, is that the machine must meet the demanding safety requirements of an underground environment — which is the starting point of the SM series design.

Safety Comes First in Mining Machines

In a hazardous gas environment, any electrical spark, abnormal temperature or static discharge can have serious consequences. The biggest difference between a mining machine and an ordinary industrial one is that its electrical and operating logic has to be re-examined around safety: from the motor and control components to every protective device, nothing may act as an ignition source.

The SM series is designed for hazardous gas environments and puts safety, reliability and stability ahead of performance figures. For mine operators, that means the unit can be deployed underground with confidence rather than being kept in a safe area and forced to push air down a long line.

Air-Cooled and Water-Cooled: Two Lines for Different Mines

The SM series offers both air-cooled and water-cooled options, and the model range is fairly complete:

• The air-cooled line runs from SM37A to SM220A, with main motor power of 37~220kW, suited to sites where water is hard to supply and layout flexibility matters;
• The water-cooled line runs from SM90W to SM250W, with main motor power of 90~250kW, suited to high-power, long continuous duty where circulating water is available.

Note that for a given model, air delivery falls as discharge pressure rises. Taking the SM37A as an example, air delivery is 6.1m³/min at 0.7MPa and 4.6m³/min at 1.25MPa. When selecting, first establish the working pressure used most often underground, then match air delivery at that pressure point rather than simply taking the maximum figure.

Service Life and Maintenance: The Long-Term Equation

Underground conditions are damp and dusty, and maintenance windows are short, so whether a compressor can keep running steadily over the long term directly affects progress at the face. Screw machines are inherently simple in structure with few wear parts, and the Fusheng SM series carries that trait forward: long service life and relatively straightforward routine maintenance, where oil changes, filter replacement and cooler cleaning need no complicated dismantling.

For mine operators this is a practical matter: fewer faults and fewer stoppages mean the underground air supply does not break off. Beyond comparing pressure and air delivery, selection should also weigh the supplier's service response and spare parts supply, because those factors tend to prove their worth only after the equipment has been in service for years.

Technical Specifications

Two things stand out from this table. First, the power span is wide — continuous coverage from 37kW to 250kW means there is a model for a small working face as well as a large mine. Second, air-cooled and water-cooled lines run in parallel, so the cooling method can follow the water supply available on site.

Industries and Applications

• Underground mining faces where the point of use moves with mining progress;
• Work areas with hazardous gas environments that require on-site air supply;
• Air supply for underground pneumatic equipment such as picks, rock drills and pneumatic chargers;
• Upgrades at existing mines where long lines and high pressure loss call for shorter air delivery distances.

Selection Advice

1. Set the pressure level first: base the working pressure on the actual requirement of the most demanding underground equipment, since every step up in pressure changes both energy consumption and air delivery;
2. Size to peak air demand: total up the requirement of the pneumatic equipment that runs at the same time, then allow a sensible margin so the machine is not overstretched;
3. Let the cooling method follow site conditions: favour air-cooled where water is hard to supply, and consider water-cooled for high-power continuous duty where circulating water is available;
4. Write safety requirements into the selection criteria: confirm the explosion-proof requirements for the gas environment on site and carry them through into the machine configuration.

Conclusion

The heart of selecting a mining compressor is never about the biggest numbers; it is about whether the machine can be placed safely next to the point of use. The SM series puts safety and stability first, then uses a 37~250kW power span and parallel air-cooled and water-cooled lines to cover different mine types and air demand scales. Underground, a steady air supply is itself part of safety.