How do compressor guide vanes work?

The inlet guide vanes are the passages made in the entry to a compressor inlet. The dotted lines in the above picture indicates the existence of these inlet guide vanes. Actually these guide vanes are a sort of blades which are the part of the casing itself, but what is the benefits of these passages?

For more information, please visit NAILI.

When the gas enters the compressor, it has a high speed and turbulency, the guide vanes guide the entering gas via some separate passages. If the gas is entering to a open area with a big cross sectional area without passages, the entering gas will have a turbulent nature, but if we have some inlet guide vane of say gas entering passages limiting the cross sectional area of the inlet gas, then these turbulencies reduces and converted to gas pressure. In this way the efficiency of the compressor increases.

Another function of these guide vanes is to control the flow of gas in to the compressor. Closing the inlet guide vanes decreases the flow of gas entering the compressor and opening the inlet guide vanes increases the flow of gas entering the compressors.

Inlet Guide Vanes (IGVs) and Inlet Butterfly Valves (IBVs) perform an important task&#;to regulate the airflow and pressure that enters a centrifugal compressor&#;s first stage of compression. Historically, IBVs had been the industry standard for centrifugal compressors. However, in the last twenty years, the IGV has come to the forefront as an option providing additional energy saving benefits.

Contact us to discuss your requirements of compressor vanes. Our experienced sales team can help you identify the options that best suit your needs.

Inlet Butterfly Valve Function

The IBV directs the airflow into the first stage of compression in a straight line. The impeller then spins the air using power from the main driver, increasing air velocity and directing the flow into the diffuser portion of the compressor. When partially throttled, the IBV reduces the inlet pressure, wasting some of the available static pressure. The pressure ratio of the overall compressor now needs to be greater in order to meet the same discharge pressure.

Inlet Guide Vane Function

Unlike the IBV, the IGV has multiple triangular-shaped vanes that allow the air to flow into the compressor in a swirl direction. The &#;pre-swirled&#; air reduces the amount of work needed from the main driver to spin the air entering the impeller. The directional flow increases as the vanes close, putting less stress on the impeller in comparison to an IBV, because of this inlet guide vanes are more efficient during turndown than inlet butterfly valves. 

Manufacturing Benefits of Upgrading to an IGV

The main benefit of updating from an IBV to an IGV is the energy conservation gained from throttling the compressor. Compressors are designed to operate at the highest ambient temperature conditions&#;so when the temperature is lower, the ability to throttle extra air is paramount. 

IGVs can save even more energy when the compressor is running at a throttled angle, which offers considerable brake horsepower (BHP) savings. The following chart demonstrates a compressor operating with a throttled IBV at 72% of the design flow, which has a power consumption of 72%. Under the same conditions, a compressor operating with a throttled IGV at 72% of the design flow, which now has a reduced power consumption of 63%. The result is up to 9% BHP savings when comparing the IBV and IGV.

Is an IGV Right for Your Centrifugal Compressor?

Contact your local authorized FS-Elliott Channel Partner Representative to find out how an IGV upgrade may improve your operating costs. 

Learn More

If you are looking for more details, kindly visit chinese electric air compressor factory.