+27 11 420 0274

info@articdriers.co.za

There are many theories on how to install air dryers; the following is a brief overview of the dos and don’ts of air dryer and filter installation.

Like its mechanical cousin, the adsorption air dryer will suffer if installed incorrectly. In the case of chemical air dryer’s the effects show up as high dew points or mechanical problems.

 

  • Too much-compressed air flowing through a dryer – will cause higher dew points (wetter air) as the air will choose the path of least resistance. In other words, the dryer/filter bank with the lowest pressure drop will get the biggest airflow. This means that the media is trying to adsorb more water than it was designed for. This situation leads to the upper “dry zone” becoming saturated and the dryer will be unable to regenerate the offline vessel.
  • Too much-compressed fluidized air flowing through a dryer, which will create high velocity, can cause the media to “hover” in the air stream within the pressure vessel (fluidised bed) this will cause the adsorption media to rub together and it can degrade to talcum powder like consistency, this is not nice in an airline, the resultant dust is very abrasive and difficult to remove from the pipeline!
  • High inlet air temperatures can also affect the ability of the chemical affect to adsorb water, in theory for every extra 5° above design temperature the chemical bed weight should be doubled ro achieve the same design dew point.
  • Due to the problems associated with oil carry over into chemical dryers, activated carbon towers are often recommended upstream of adsorption dryers to prevent contamination of the dryers bed.

In the medical layout below, the dryers should only be operated as a set, 1 running and 1 set in back-up isolatewd for the system.

Receivers

The receiver should precede the filters and dryers for the following reasons

  • The receiver will give a clean load / unload signal to the compressor, with no partially blocked pre-filter to upset the load / unload signal to the air compressor.
  • A large amount of any compressor oils and airborne debris will drop out in the air receiver, this is easy to drain. Oil-free compressors are preferred.
  • Modern air receivers are built with zero corrosion allowance (unless specified) so running lubricated air to the receiver, will reduce the corrosion on the vessel walls.
  • If the screw air compressor’s air/oil re-claimer filter breaks, the oil from the compressor will flood the receiver and not hydraulically destroy the pre-filter elements, This gives the airline filter element the best chance of survival. It also means that the filter element debris will not get forced into the inlet of the air dryer.
  • The air dryer also sees the mean average airflow and not the spikes that it would see if it were placed before the receiver. This allows the dryer to be more stable and provide a more constant dew point.

If required, you can install a secondary dry receiver downstream of the dryer / filter bank.

This will give you a limited dry air supply for the plant. Place receivers on the coolest side of the building (South side) and paint them white if possible, this will ensure the best water dropout. Receivers will only remove some 2 – 3% of the water contamination, but should be drained +/- every 4 hours depending on receiver size.

Air Filter Installations

Like air dryers, filters should not be operated in parallel, if this is attempted it leads to short element life cycles and rising maintenance expenditure. It is impossible to direct equal air flow through two or more inline filters when operated on parallel.

The element with the lowest pressure drop will lead to a priority air flow through it. This in turn leads to premature element failure and anti-entrainment sock disintegration. Element failure means now effective filtration of polluted airlines. Sock failure leads to material being carried downstream into the air system. There it will foul equipment and cause general mayhem!

 

 

Note, air flow is from inside the core to outside

Room Ventilation and Access

Air dryers should be installed in a well-ventilated area that provides cool air to the compressors and in turn reduce air inlet temps to the dryer. A 1.5-meter free access area around the dryer is required to allow service technicians to maintain any part of the dryer.

Care should be taken that compressors do not exhaust hot air onto an air dryer. Hot waste exhaust air should be exhausted outside the compressor house. See drawing. As a good indication of a well-constructed compressor room, if you are sweating inside the compressor room, the ventilation is poor. Change it!

Have cooling air inlets installed at low levels (South side) with the discharge vents on the opposite side of the room at high level, designed for “through flow”ventilation.

Ensure that there is plenty of natural light and floodlights for nighttime repairs or supervision. Ensure that the room is kept spotless it will promote good workmanship on the equipment, no one will dare to leave the room in a mess.

Typical Air Compressor Room Layout – Side Elevation

Contact Info

12 Rotterdam Road,
Apex Benoni

Email: info@articdriers.co.za

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Contact Numbers

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Direct Service: Taryn Pretorius
Mobile: +27 84 652 8378
Email: taryn@articdriers.co.za

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Mobile: +27 84 315 2285
Email: waylon@articdriers.co.za

Contact Numbers

Direct Sales: Christen Viviers
Mobile: + 27 72 927 4880
Email:  Sales4@articdriers.co.za

Direct Sales: Griffin Hopkins
Mobile: +27 84 449 0274
Email: Sales3@articdriers.co.za

Vedré Van Der Schyff
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Email: vedre@articdriers.co.za

Paul Cockfield
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Email: paul@articdriers.co.za