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If the ‘natural’ cooling of your compressed air that's shown on other pages here at doesn’t do the trick, and you’ve still got water dripping from your air valve exhaust ports and blowing through your air tool onto your work place, you’ve got to take it up a notch, in terms of air treatment.
If you've just arrive here on this page, the thread for dealing with compressor generated water begins on this page.
There are a number of pieces of equipment that you can purchase and install to cool and dry your compressed air.
We've offered ideas below, roughly in order of lower cost to higher cost. That cost might be reflected in higher purchase price, or higher operating costs, depending on the solution selected.
Aftercooler
The first piece of equipment we'll talk about is an after cooler, a water jacket style, also known as a ‘Shell & Tube’ type.
This style uses cold water to cool the compressed air.
The compressed air from the discharge on the compressor flows into the after cooler and through one of a number of tubes inside the shell.
Outside the tubes, cold water is flowing throughout the shell, either in the same direction as the air flow in the inside pipe, or in the opposite direction depending on the brand and specifications.
As the warm, wet air from the compressor passes through the tubes, heat is radiated out of the compressed air, through the tube, and is removed by the cold water. Water condenses out of the compressed air stream as a result.
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One of the benefits of this type of compressed air cooling system is that it is low technology. Installation is uncomplex, and it – overtly at least – doesn’t consume energy to function.
In earlier times it was common to have water piped from the plant water supply into the water jacket, and out the other end to a sewer. Water was cheap and abundant.
However, water costs and sewage costs have put an end to that practice as companies are charged first for the water, and then for the sewage costs for that volume of water, even if it doesn't flow into the city's sewers. The shell & tube type of cooler now normally recirculates the same water in an endless loop.
That development requires a pump, which uses energy, more complex control circuitry, and – depending on the temperature of the water as it exits the cooler, perhaps a cooling tower of some sort which adds significantly to the equipment cost, and may - too - involve the consumption of energy to run.
A shell & tube type compressed air cooler starts out as being uncomplex and low-tech, but could grow quickly into a much more complex and expensive solution.
Refrigerant Dryer
Another post-receiver air cooler / dryer is a refrigerant system.
It functions similarly to your home refrigerator, with a compressor and cooling coils, but rather than pumping heat out of a closed box, the compressed air passes through cooling radiator(s) in the dryer that decrease the temperature of the compressed air.
The idea of the aftercooler or refrigerant dryer is to lower the temperature of the compressed air so that water vapour in the air condenses where you want, and not where you don’t.
Things you’ll need to know to get your refrigerant dryer sized are:
The refrigerant dryer will provide a range of drying predicated on how much air going through it and at what temperature it is.
If you undersize the refrigerant dryer - purchase a smaller model than necessary to save capital costs - you will find that the unit cannot provide the cooling desired, and you undermine the purpose of the unit in the first place. Money saved here will cost you in maintenance and components downstream.
It's important to ensure accuracy in sizing the unit, or err on the side of caution and oversize the dryer a bit. The downside of getting an oversized refrigerant dryer is the cost goes up, both in terms of purchase and operating the unit.
In many plants there will be an aftercooler - such as a shell & tube style - installed before the refrigerant dryer as the air temperature coming to the refrigerant dryer from the compressor would be too high for the dryer's capacity without it.
Another form of dryer used where the air applcation demands it is the desiccant dryer. Please find information on it here.
From water solutions option 3 back to home page.
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