The air in the atmosphere contains moisture which increases with temperature. The suction of moist air by the compressor means the moisture in the air enters the air line (Türkçe metin: "...bulunan nemin ve hattı ve oradan da pnömatik cihazlarla gitmesi... " kelime eksik. Tercümede "hava hattı "olduğu varsayılmıştır.) and to the pneumatic devices from there.

    The possible consequences of condensation of moisture in the compressed air installation is corrosion in the air lines and pneumatic devices and the  formation of a gum like residue of the dust in the sucked air and oil from the compressors with the moisture. This residue may cause narrowing of cross sections which results in resistance in the pressure air lines. In addition, it may clog the pneumatic circuits and adversely affect the operation of the device.

    Main problems that may arise in compressed air lines and pneumatic devices is the increase of product faults as the result of (non-)operation (Türkçe metin: "kontrol sistemlerinin doğru ve beklenen hızda çalışma-larının bir sonucu olarak" - tercümede calişmamaları olduğu varsayılmıştır) of control systems correctly and at expected speeds and the increase of maintenance costs for air lines and pneumatic devices. For this reason the air exiting the compressor needs to be dried.

  
    To specify the dryness level or the amount of moisture in compressed air the term Dewing Point is used. The Dewing Point under pressure is the temperature at which the moisture in the air starts to condense at a given operation pressure. A low Dewing Point is an indication that there is little water in compressed air.

   Starting from the fact that the dewing point at a high pressure is a lower dewing point at a lower pressure, one of the methods to remove moisture in compressed air is to first increase the pressure and cool the air and extract the condensed moisture and then lower the pressure. This method is used only for small flows or when there are no dryers because it will result in high operation costs.

     
     This method may be described as heating the compressed air moisture to temperatures near room temperatures again after the cooling of the compressed air similar to done in refrigerators or air conditioners. In these dryer types because Freon is used as the cooling gas they are also known as Freon dryers.

(... basınçlı havanın soğutulması sonrasında yoğuşan nemin basınçlı havadan (??) yeniden oda sıcaklığına yakın bir sıcaklığa kadar ısıtılması olarak tanımlanabilir. )

   Cooling type dryers are groped in two groups in terms of the dryer control. One of these is the thermal mass dryers and the others are direct expansion dryers. In both types of dryers there are two circuits being the compressed air circuit and the Freon circuit. They are different in that the compressor compressing the  coolant gas in the Freon circuit operates continuously or in start-stop mode.

 (.... dorudan genleşmeli kurutuculardır. )

   Cooling is made in the same manner in all the cooling type dryers. Two separate circuits can be mentioned in these dryers. These are gas circuit and compressed air circuit.

    The operation system of cooling type dryers starts with a Freon compressor also called ecowatt. Here the Freon in gas stage is compresses and enters the condenser where it liquefies. The cooling capacity of the Freon gas is higher when in liquid form. The pressure of the liquid Freon filtered by the cooler filter is reduced at the expander. During this not only the pressure is lowered but at the same time it is cooled. The cooled Freon is still in liquid form at this stage. The cooled and liquid Freon enters the cooler/air heat exchanges and here cools the compressed air and caused its moisture to condense. During this process the heat in the compressed air is transferred to Freon and the liquid-gas mixture is formed. The liquid-gas Freon which is transferred to the cooler separator from here is separated and only the gas Freon is let into the compressor to protect the compressor.

   The water existing as steam in the compressed air cooled by the Freon gas is condensed and is separated by the water separator and discharged. Later, before the cooled compressed air leaves the dryer it meets the hot compressed air coming from the compressor in the air/air heat exchanger. Thus both the pre-cooling of the compressed air entering the dryer is achieved and the air about to exit the dryer is cooled to a temperature near room temperature. This way the continuation of condensation in the compressed air lines is prevented after it exits the dryer.

,(...hava/hava ısı değiştiricisinde...??)

   AAG compressed air dryers condense the relative moisture in the ambient air sucked by the compressor and in all models the discharge of the condensed water is controlled by the double timer (wait-discharge) relay and electro valve. Again the electronic thermostat is all models controls the temperature at dewing point. When the air temperature falls below the temperature at dewing point the thermostat solenoid is fed by the by-pass  valve.

   The valve gate opened by the thermostat gives hot gas flow to the cold air flow going from the compressor to the evaporator. With the balanced differential temperature the freezing of the condensed water and stopping of the air dryer is prevented. The valve shut-off when the set differential temperature is reached and the cooling circuit starts to operate by the same method. The dewing point is +3°Cas standard.

   AAG air dryers have double stage exchangers.

  1. Prepares the hot compressed air with pre-cooling and then it reaches the dewing point in the cooling chamber. The air - water are entering the condensed water turbulence chamber are separated.

  2. It operates with the basic principle of cooling and condensing  up to the dewing point  (+3 °C) and transfer form moisture (gas form) to water form and the discharge of this water.