Tag Archives: Compressed Air

A Brief Explanation of Centrifugal Compressor Valves

Industrial compressorThe valves in a centrifugal compressor are responsible for regulating air intake and the bypass air.  This regulates the air discharged and also works to prevent surge. Within a compressor, you can typically find several different types of valves that each serve a unique function. Learn more about a few of the most common compressor valves below!

Butterfly Valve

This type of valve can be found in a wide variety of industrial applications. In compressors, butterfly valves are often used as air inlet valves. An inlet butterfly may be either electronically or pneumatically actuated. As the butterfly valve closes, effectively reducing the inlet flow and limiting the compressor’s ability to generate pressure and airflow.

Ball Valve

This type of rotary valve functions similarly to a butterfly valve, but it regulates pressure using a ball with a hole through it instead of a circular plate mounted on a rotating shaft. By virtue of this design, ball valves are able to create a more complete seal than butterfly valves, which makes them ideal for regulating the flow of gasses. They are also generally less prone to pressure drops than butterfly valves.  These are mainly used for the blow off function.

Inlet Guide Vane (IGV)

This is another common type of inlet valve, but its design is distinctly different from that of a butterfly valve. An IGV regulates airflow using a series of radial blades or “guide vanes” arranged in the intake. When the valve is open, the vanes are parallel to the airflow. When it’s fully closed, the vanes are perpendicular to the airflow. As the guide vanes are rotated from open to partially closed, they cause the air to rotate in the same direction as the impeller. This reduces the incidence angle of the incoming air and consequently reduces that amount of energy required to produce pressure. This design characteristic makes IGVs an especially efficient type of intake valve.

Blow Off Valve (BOV)

This type of valve is used to prevent compressor surge. A BOV is also referred to as a bypass valve, but BOVs vent excess air into the atmosphere. The BOV can be found on the intake pipe between the turbo and throttle body.

These are just a few of the many components that work together to make a compressor function effectively. At Case Controls, we design and build industrial control systems that optimize compressor efficiency and prevent costly breakdowns. To learn more, feel free to give us a call or contact us online today.

Understanding Air System Artificial Demand

Companies that rely on compressed air systems are constantly looking for ways to make them run more efficiently. Many of these companies end up spending more money than they need to on an annual basis simply because their existing air systems are inefficient and wasting air. One of the many reasons that this can happen is due to something called artificial demand.

Essentially, artificial demand is, according to Compressed Air Challenge, “the excess volume of air that is required by unregulated end uses as a result of supplying higher pressure than necessary for applications.” Artificial demand in an air system is something that needs to be considered as part of the overall air system, and it should be monitored to make sure your air system is running properly.

In more lay terms, this artificial demand is the extra pressurized air in the system that is not being used or is being generated even though the attached components or end applications are not being used.  The higher pressure causes more CFM to flow through orifices, leaks or similar types of openings.  This means that the system is always running as though it needs to provide pressurized air throughout the system, even if the actual demand isn’t there. For example, a 20 PSI increase on a ¼ pipe will cause 10 more CFM to flow out the opening.

Many compressed air users don’t realize artificial demand exists and therefore don’t know how to reduce its effects. Companies can reduce the artificial demand by implementing an overall controls system to maintain the compressed air system at the actual pressure that is required. This minimizes extra strain on generation units, reduces pressure being held throughout the system unnecessarily, and can decrease utility costs while increasing the lifespan of the system overall.

Is your company currently using an air system where the supply and demand are out of whack and not conducting true load sharing? Are you operating your air system at a higher pressure because it is not under control?  Case Controls can help you with this problem by offering up real solutions. We can provide you with compressor management equipment that will bring your artificial demand down and see to it that your equipment doesn’t waste any energy or money when it’s running. Whether you want to install AirMaster load sharing solutions for centrifugal compressors or you want us to take a look at your current setup and give you our opinion on your best course of action, we are happy to help you get your facility under control.

Call us at 812-422-2422 today and find out how we can help you get the most from your compressed air equipment.