Compressed Air Optimization

What's the challenge?

If it's water, fit a dryer, the type will depend on how dry you want the air.

The most important thing to get to grips with is, curing air leaks, they cost a lot of money.

Best regards,

John

The challenges are Water in the system and Electricity usage.

To reduce electricity usage, reduce the leaks from the system, as recommended in #1↑.

Hi jmakgata,

According to the manufacturers information they each have a Free Air delivery of 35.88 cubic Meters per Minute, with a built in dryer.

So, you will need to check out the dryer side of the unit and ensure the compressor has adequate cooling air available.

35.88 Cu.Mtrs/Min. (1267Cu.Ft./min) is a lot of air and even well maintained air systems can easily have 10% of air leaks, so, I would guess you have the potential to save a lot of electricity (money).

I have a customer with compressors half the size of yours and found leaks that were costing him £30,000-00 per year. An expenditure of £1000-00 on bits and pieces cut it to £3,000-00 per year.

So the sooner you start the sooner you start to save.

If you invest in an Ultrasonic Leak Detector you can find the leaks while the plant is running rather than wait until it is quiet.

Best regards,

John

"Ultrasonic Leak Detector"!!! Call me old fashioned, but what's wrong with soapy water and a brush?

Tony

In addition to #5↑ it could be that, if electricity consumption is high due to possible leaks, any existing air drying equipment might be over-extended due to the excessive throughput of air towards the leaks. So concentrate on fixing the leaks first and review the drying arrangements second.

Review also the original sizing calculations for these compressors. Has the air delivery system been extended and lots of additional air-consuming gear been bolted on since they were originally commissioned without looking at the sizing and capability of the compressors and their drying equipment? Is that why there is moisture in the delivered air, perhaps?

Review the maintenance records for the drying equipment also, and check that everything is as it should be.

Air contains water; that's why it rains and snows from time to time. Once compressed for industrial use and cooled back to ambient, there is a tendency for the water that has passed through the compression system to condense-out. To avoid this, as in #1↑ fit a dryer in the system. Talk to the compressors' vendor as to how to best go about this. Having some idea about how dry the air needs to be is a good starting point. Dryness is indicated by the value of the "dewpoint", which is the lowest temperature of a surface on which the water in the air will begin to condense. For a rough-old pneumatic drill, drying is unneccessary; for instrument air around a factory complex, a dewpoint of -40degC would be a typical specification so as to avoid the risk of corrosion and malfunction through rusting of any steel components in the instruments and valve motors. Dewpoint specification depends upon latitude: -40degC dewpoint would be a nonsense in Singapore, for example, as the ambient rarely drops below +20degC. The facility in question may well have existing performance standards that must be followed.

If the water is seen in the piping downstream of compressor, then the following can be checked.

a) This 2 stage oil injected screw machine may have moisture separator at each stage after the stage coolers, to knock off the condensed water. The separator drains out the water automatically thro' level sensing. You may check up whether the drain valve is functioning. Being oil flooded compressor, the carryover of water to compressor would not have caused any issue

b) If the inter/after coolers are water cooled shell &Tube type cooler, also water entry due to tube rupture is possible.

c) If the water is found downstream of the Dryer, then there could be a possibility of the regenerative dessicants in the dryer have outlived their life and are not absorbing the moisture.

d) If the downstream consumers are not overloading the system, the excess power consumption may be due to the excess mass flow corresponding to the lower ambient temperature, since this machine may not have auto regulating inlet slider valve for capacity control based on mass flow or excess motor current.

King cow Protector

Your compressor is said to have a built in dryer which means that there is also a sump that requires periodic draining. Draining should be automatic, but don't depend on it, check it periodically. The air is normally delivered using overhead piping. This piping should be installed with a downhill slope and a sump installed at the far end. The tap tees should be installed with the openings facing upward and then routed over and down to the delivery point. The amount of water collecting in the end sump is an indicator of how well the dryer is working.

Water vapour in the atmosphere when drawn in and compressed will get hot and then gradually cool throughout the system and then condense in the pipework and machines.

This water can be filtered and separated anywhere it is a problem and then dumped.

If you do not want water in the system then you need to ensure the air is cooled at source to a dew-point below the ambient temperature. Thus the air stays dry because it warms up as it passes through the in the system.

For ambient temperatures above freezing you can use a fridge dryer. Below freezing needs another technique. There are membrane and desiccant dryers to do this job.

If you already have a dryer then something is wrong. Check the working temperature of the after-coolers. If they are not lowering the temperature enough the hot air will overload the dryer. Check the dryer drains. Are they working. If not then the excess water builds up and carries over into the system.

You need an auto oil/water separator, they remove any liquid contaminates and automatically dump them out when the reservoir starts to fill, I've used mine for years without any trouble for spray painting.

Bazzer