What’s condensate?

Condensate water is usually contained in all installations with compressed air, in small or big quantities, in proportion to the volume of air produced and depending on the season and on the geographical area.

It starts from 1 ml/m³ (in winter in temperate climates) up to more than 20 ml/m³ (in tropical areas).

The compressor, as we all know, compresses the ambient air and consequently all the parts in it, including the steam.

This steam introduced in the compressed air installation (plant), condensates creating water. In this condensation process, the water combined to all the polluting substances in the air as oil parts discharged from the compressor in the compressing phase, originates an emulsion that can create serious problems to the plant and to the production machinery.

All this process has to be managed in the right way and the function of the condensate drain system is fundamental.

Condensate quantity in the drainage points

The biggest quantity of condensate produced in the plant (>60%) is collected in the compressor “aftercooler” or in the cyclonic separator. Another part of the condensate (>30%) is collected in the refrigerant dryer. The remaining part is collected in the in line filters.

What is the composition?

Condensate is mainly composed of water. In installations working with lubricated compressors, in the condensate you can also find traces of oil superior to  2.000 ppm. In the event of installations working with “oil free” compressors you don’t find oil traces but the situation is not improved because the condensate has a ph value <7 (acid) and with an high corrosion level. Considering that the air is taken from the production plant surroundings the condensate it is enriched with dust and contaminants of different kinds.

The high concentration of contaminants requires, according to the law, a  depuration treatment of the condensate that can be delegated to licensed companies for the recovery of  polluting liquids or by using a water/oil separator with active carbon that retains oils and the contaminated substances, and enables one to  discharge the clean water into the public sewing system. This last mentioned solution is much more economical and easier.

Which damages can it cause?

The circulation of condensate in the system is the origin of damages and anomalous wear of the machinery using compressed air and in some manufacturing processes, for example the painting, the damages are not only on the machinery but also affect the production.

What’s the role of electronic drain systems?

Correct condensation water drainage in the production system and in the air compressed treatment system allows to considerably increase the efficiency of the machines, thus limiting considerably the wear and the maintenance.

According to which technological principles does the condensate drain system work?

You can find various condensate drain systems with different working technologies on the market.

The simplest ones make a timed discharge: a timer circuit controls the T-ON and T-OFF times of a solenoid valve, considering the working/pause time fixed on the control panel. These systems require a periodic setting of the discharge time according to the season. There is no fixed rule for the optimal discharge setting time during the year because it could be too long in dry and cold period causing high loss of compressed air or too short in warm and wet period.

There are different timed condensate drainage systems on the market, some are more or less easy to regulate and some others are even self setting, i.e. automatically and cyclically adjusting the discharge time at every opening time. The detection sensor in the solenoid valve, checks the presence of condensate: when the level of condensate is low, the timer circuit stops automatically the discharge and limits the loss of compressed air, without seasonal setting (see model AutoDrain).

A more performing alternative are the level electronic condensate drainage systems. These systems are called “Zero Air Loss” that means without loss of compressed air. This is possible thanks to a collecting tank, integrated in the electronic condensate drain, monitoring the level of condensate through  a special level sensor. A microprocessor electronic circuit controls the complete condensate drainage; it opens the solenoid valve each time the max water level is reached,  and stops it when the min. level is reached.

The condensate draining system has many useful functions to control the anomalous situations such as the control of siphon bags, which  stop the  checking of the condensate level, or the automatic unlock from clogging and, in worst cases, the remote alarm by a “potential free” contact connected to control system.

These systems seem to be more expensive if you compare the purchase price but if you consider that you are not loosing compressed air at all, then you will save money in the medium/long period.

How to choose the right electronic condensate drain system?

The choice of the right product, correctly positioned, has not to be considered only looking at the price: it’s not true that the more economical one has fewer skills than the more expensive one, and it’s not sure that the more expensive model can do a better job in every drainage point of the plant than a cheaper one.

The chart below can help you to make a right choice.

Impianto dimensionamento
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