What is the best bang for the buck when we are talking about compressed air treatment?
Do you have an auto-drain installed in your compressor receiver yet? If not, at the very least, you are draining the receiver manually a couple of times a day in the plant, and at the end of every day of use in the home workshop?
An example of a compressor tank auto-drain is shown below.
Much of your down-stream air treatment equipment could be either over taxed, or even rendered useless, if the compressor tank is not drained regularly.
To make draining the receiver most effective in ridding your compressed air system of water, the cooler the air is in the compressor tank, the more water will drop out of the compressed air in that tank. This is water which you can eliminate from your system by opening the drain manually or let the your auto-drain void from the tank as it cycles. This is water that will not get to your air tools or air valves and cylinders.
If you've high demand on your compressor, consider adding a second receiver tank plumbed quite a distance from the first, to allow the air to cool naturally as it flows to the second tank.
In fact, if your extra compressor receiver was placed on the other side of the plant, and you ran your main air lines from the first compressor receiver up to the ceiling and around both sides of the plant, you'd have a "ring" supply of compressed air, which is the recommended method of plumbing air throughout a plant.
You will have to take into account where and what the demand for your air is and ensure that the added plumbing doesn't "starve" any application. By having that second receiver installed, you can manually drain the first tank daily, auto-drain the second automatically a number of times each day, and remove substantial amounts of water at the receivers rather than later down-stream where the water can cause you problems. Consider installing an auto drain in both receivers eliminating the worry about a manually drained receiver being forgotten and filling up with water.
The second receiver offers an alternate, energy-consumption-free method of naturally cooling air from your compressor.
If your compressed air travels from the first receiver to the second without being used in between, immediately after your secondary receiver - and before the air gets to any of your in-plant applications, install a general purpose filter sized for the expected demand of the plant to pull any free water from the air stream as it exits the tank.
Depending on the size and capacity of your receiver, the general purpose filter must have the flow capacity of the total flow demand of your plant, not just what the compressor output is rated for. If it's possible for all air consuming devices in your plant to come on at the same time, that's the flow that will be moving through the first filter so make sure the filter has the flow to handle it.
Space being available, install a first general purpose filter right at the tank, and then a second one as far away from my last receiver as possible, to allow air flowing to it from the receiver to naturally cool in the longer flow path, allowing more water to condense and be removed.
There are many additional steps that can be taken to remove water from your compressed air, each one usually more complex and costing more in up-front purchase, and energy consumed to operate them.
The intent here is to give you options that allow you to improve water removal in your system to a level that suits your needs, at the lowest possible cost.
Not everyone needs air that's desert dry, and since it costs a small fortune to get larger quantities of compressed air to that level of dryness, you will not want to do so if your plant applications don't require it.