Toughest Brands   |  Unbeatable Support

Don’t Drive Off On Engine-Driven Compressors

Engine-Driven Compressor

What’s an Engine Driven Compressor?

Engine-Driven compressors are not the most common units you see in production. When you think of compressed air, you often think of the traditional units wired into a power source. These units are reliable and output large quantities of compressed air. Electric-powered compressors are the cheaper options due to the widespread use and availability of the technology.

Diesel engines have increased in price over the recent years, nearly 25%, but with this comes major upgrades in technology and performance. This has led to the electric compressor becoming more widely used due to the lower cost. However, engine-driven compressors shine in environments where power supplies are not available as they only need diesel.

If power is not available on-site, an electrical compressor will be an oversized paperweight rather than a tool to get the job done. Engine-Driven is the only option left for these environments, so if you need one of those machines, you have to be willing to deal with the price increases, as the benefits far outweigh the costs.

These compressors are pretty self-explanatory when you think about it. Rather than an electrical box, they have an engine typically powered by diesel. This power source being self-sufficient allows for versatility in site locations and applications. You have to bring the fuel to your system rather than your supply to the power.

Aside from the power source, engine-driven compressors are the same as their electrical counterparts. Compression chamber, pump, and process are all going to be the same, however the engine-driven compressor may have additional filtration included. You may not experience much difference in CFM output, but you definitely will in run time.

You will need to be much more aware of how long your engine-driven compressor has been running to make sure you have enough fuel.


How Do Engine-Driven Compressors Work?

When it comes to the operation of a diesel engine, it uses combustion just like your car engine. This process requires igniting the fuel to generate heat and energy to cause combustion. Fuel and air combining results in an explosion to create the desired energy needed for compression.

So how exactly does this process work? Let’s go through it in a step by step process so we can really understand what makes these engine-driven compressors different from your traditional electrical compressor.

Once the engine is turned on, the battery will start the pistons and they will begin to move up and down as a result of the rotating crankshaft. These pistons push air through the cylinders into a compression chamber that will double as a combustion chamber for energy to be created. Air is compressed and forced into the chamber the air heats up.

Fuel is then pumped into the hot compressed air and the results are explosive. As the fuel ignites it sends the force from that explosion to power the pump. This process is repeated for as long as compressed air is needed and will stop when it is turned off or runs out of fuel. For these explosions to occur the temperature of the engine needs to be warm enough.

Some engines will have a glow plug in place to help the air reach the required temperature for ignition. Glow plugs emit heat and bring the air temperature up for the few moments after the engine is turned on. It will run until the first fuel ignition. It will turn off at this point as it is no longer needed. The plug will turn back on the next time the engine starts back up.

In your typical engine-driven compressor, your controls are going to be straightforward compared to your more complex stationary electrical compressors. Rather than needing the interface to control the engine, it is mechanical and tied directly to the compressor in your diesel-driven units.

Your compressor is going to consist of two main components: an air end and a gas engine. The air end is responsible for compressing the atmospheric air that has been pulled into the compression chamber. The gas engine powers this action so that the pistons move and reduce the space the air is in.


Need A Visual?


Let’s Break Down the Process

The process of compressing your air is broken up into stages called strokes, with each one providing a different action that is necessary for compression. In order to adequately use the air and fuel mixture, they need to be ignited in the compression chamber before they can be moved along to actually power your equipment. There are going to be 4 different types of strokes:

  • Intake Stroke
  • Compression Stroke
  • Power/Expansion Stroke
  • Exhaust Stroke

Each stroke plays a different role in the compression process so they are all equally important as you need all 4 for the system to work properly. You may find one more important to your system and how it runs, but you won’t be making air without each step.


Intake Stroke

The intake stroke is your to getting the process started, if there is no air intake there is no air being compressed. The carburetor makes sure that the right quantity of air and fuel are entering the compression chamber during this process. The piston will reach its lowest point at the end of this stage, so that the air and fuel mixture will fill the entire chamber.


Compression Stroke

After the intake stroke has finished, the compression stroke begins. This change in direction of the piston causes the inlet valve to close off. With the valve closed and the piston shrinking the space that the air has to exist in. At the end of the compression stroke, when the fuel mixture is the most condensed, a spark plug will produce a spark.


Power/Expansion Stroke

The spark caused by the spark plug will ignite the mixture, resulting in combustion. This release of energy in the form of a miniature explosion, forces the piston to the bottom of the chamber. This process turns the energy from fuel into mechanical energy to power the compressed air system.


Exhaust Stroke

The final step in this process is removing the byproducts of combustion. During the exhaust stroke, the exhaust is forced out through the exhaust valve on the piston’s upstroke. The exhaust is pushed out so that the process can be restarted on that next downstroke.


Cooling Phase

Although it is not an official stroke phase, cooling is incredibly important to engine-driven compressors. A lot of heat is being created by the air being compressed, as pressure build up is energy build up. This excess heat occurs from the process of compression and does not even include the combustion aspect of engine-driven compressors.

Engine-driven compressors operate with two different cooling methods, and that is dependent on the type of air end on the compressor. Reciprocating air ends are going to typically use natural air convection to cool off the air and this is assisted by cooling fins.

Rotary Screw Engine-driven compressors operate with a different cooling system as they rely on air-to-liquid heat exchangers to remove the excess heat from the air. This heat exchanger will pull the heat from the air into the cooler liquid that it is passing by.

No matter the type of engine-driven compressor you have, cooling is incredibly important to the health and longevity of your equipment.


So Why Would I Get an Engine-Driven Compressor?

Not being tethered to a power supply is the biggest benefit of going with an Engine-Driven Compressor. By filling the engine with gas you can take the compressor to the job site, rather than building the job site around your compressed air system. 

The portability of the compressor puts these machines in a league of their own, and the only downside is needing to purchase fuel and having dirtier air; however, if you are using an engine-driven compressor you most likely are not super concerned about your air quality. The portability lets you set this machine up in even the most remote locations.

As the technology for this equipment advances, the costs decrease and maintenance intervals increase. It is now feasible for service windows to be near 1000 hours, once every two years, rather than every 250 hours, as was standard before. This allows you to save money and focus on what you really need to get done with the compressed air, not managing your air.

Even though maintenance intervals are increased, simple routine checks can give you peace of mind in regards to your compressors overall health. You’ll want to keep an eye on fluid levels and the vibrations on the bearings. This will let you know the state of the compressor and if you may need to recondition your engine-driven compressor.


Additional Considerations

Although Engine-Driven Compressors can get work done in places traditional electrical compressors cannot, they are less safe than their stagnant counterparts. Electrical units do not have a risk of injury from hot components, like the exhaust pipe or muffler. They also do not require combustible fuel to be hauled to and around the job site. 

No fuel being hauled around means no spills either, as diesel spills can contaminate the ground and damage the local ecosystem. Electricity is also better for the environment and the quality of compressed air. In the past engine-driven compressors were the only options for portability, but with technological advancements electric-powered compressors are now just as portable

You’ll need to keep an eye on your compressor as you would with any equipment just to make sure it is running properly. Engine-Driven Compressors are work horses due to their ability to work in the toughest conditions, bring power to the most remote locations, and a more familiar engine to most people.


Before You Buy

As with all equipment purchases, you want to make sure that the machine you are getting is exactly what you need for your operation. Although they may be less common than electrical compressors, Engine-Driven Compressors fill the void for those that need compressed air at different locations. 

Don’t let the less than ideal parts of the compressor deter you from the perfect fit for your operation. If you are considering an Engine-Driven Compressor, your operation most likely requires one due to the circumstances. You came to the right spot for the best available Engine-Driven Compressors on the market.

If you are looking to get your own you need look no further than Follow this link to see our ever expanding inventory of engine-driven compressors.


Learn More From The Source

Can't Find What You Need?

Connect with an Engineer Today!