Compressor Auxiliary Systems

Single acting

Splash, splash and pressure, splash and gravity and full pressure

Splash

Uses drippers, slingers or even crankshaft turning to splash oil throughout entire crankcase(lubricate all moving parts)

Splash and pressure

add pressure pump to positively supple oil to rotating elements in crankcase

Splash and gravity

oil carried up the crankshaft by a ring that hangs onto sump(fast running)

limited to pressure from the force of momentum

Full pressure

Less bearing wear, not dependent on crankcase oil level, oil can be filtered, and excellent protection on start up(pre-lube pump)

Why pressure lubrication more suitable for double-acting compressors

main frame separated from cylinder(distance piece)

crank case oil can’t reach cylinder

cylinder oil cant drain back

Large double acting compressor lubrication

internal and external

Internal

Critical to long life of machine( pumps, piping/galleries, cooling and filtration systems

Coolant pumps

External gear(most common, vane, gerotor and internal gear

Cooling systems

shell and tube oil cooler, retain viscosity and remove heat

Crankcase breather or vent

installed on top of crankcase prevent pressure build up

Periodic maintenance of oil coolers

scale/sludge build up, sacrificial zinc anodes, and corrosion or erosion of tube bundles

why use External lubrication

type of gas, discharge psi/temperature, type of oil

External

Pump to point and divider vanes

Pump to point

Like dcv, plunger pumps(positive displacement) runs off cam driven by crankshaft

Cons: each pump need own alarm/safety shut down systems

Divider vanes (overcomes problems of pump to point)

1 pump, filtering devices, divider vales, lube meter, no-flow device, remote operation

Rupture disc

after pump to prevent over pressure

Flowmeter panel

set and record pump flow and pressure

No-flow valve

sends alarm or shuts down the compressor if no flow occurs

Master & secondary divider valve

master divides flow to each secondary

secondary divide flow to each necessary injection point

block can’t tolerate foreign particles, air, oil or leaksInta

Intake air filtration must

low resistance, accumulation capacity, good separation, mechanical strength

Paper filters

3-5 micron, rip easy due to abrasive material, bad for dirty environments, venturi silencer

fabric filters

more resistant to abrasive material and high temp, can be cleaned by blowing air

Oil wetted labyrinth

good for fine particles, but regular maintenance required and relubrication

Oil bath

air has to go through oil bath before it escapes, baffles to prevent sediment at bottom from agitation

Inertial filter(pre cleaner)

special shaped vanes spin air causing heavier dirt to fly out

Cylinder cooling

removes heat of compression with cooling gas

coolant water temperature higher than temp of incoming gas prevent condensation

Water-cooled packing

High pressure or non-lubricated application to keep at operating temperature

water must be clean/filtered and have additives to prevent scaling and plugging

Piston rod run-out/rod-drop

proximity probe on distance piece or in cylinder