Desiccant air dryer maintenance is important for industrial production. Because constant, stable, and reliable compressed air is the basic guarantee of safe production. The desiccant dryer plays a vital role in the process of drying and purifying compressed air. Therefore, routine maintenance of the adsorption dryer is a basic measure to ensure air quality.
（desiccant air dryer maintenance）
Why do we need desiccant air dryer maintenance?
Firstly, adsorption dryers contain many valves and pneumatic spare parts. They are subject to mechanical wear and tear. Therefore, they need to be replaced regularly in order to ensure stable operation.
Secondly, the filter intercepts and separates water, oil, and dust from the compressed air. It needs to replace the filter element around 8000h. Otherwise, it will generate a large pressure drop.
Thirdly, the main adsorbent of the desiccant air dryer is aluminum oxide or molecular sieve. The water& oil in compressed air will affect their adsorption efficiency. Thus, in order to ensure the effectiveness of the dryer, we also replace the adsorbent regularly.
(1) Wear parts for desiccant air dryers
Adsorption air dryers have four main wearing parts. So we must do a good job for desiccant air dryer maintenance.
① Desiccant beads are the main consumable for regeneration dryers. They are subjected to frequent impacts of pressure, water vapor, and heat. So the adsorbent performance can deteriorate. Of course, we use high performance activated alumina as the main adsorbent. All properties are greatly improved. In particular, the compressive strength and the resistance to liquid water immersion have reached a very high level. The life span is up to 2 to 3 years.
② The controller is the command center of the desiccant dryer. With the development of electronics and PLC technology, there has been a qualitative leap forward in terms of control accuracy and reliability. Of course, the heating and regeneration elements need to be further improved. The other control elements are no longer wearing parts.
③ The control valve is another main wear part. Frequent switching and long-term exposure to moisture are important reasons for valve damage. So we need to do desiccant air dryer maintenance well.
④ Silencers are also prone to failure. Its main manifestation is the blockage of the exhaust channel. Once blocked, it will bring fatal damage to the regeneration air dryer. This can lead to a reduction in the regeneration performance of the adsorbent. Therefore the silencer is the focus of the daily maintenance of desiccant air dryer.
(2) Factors influencing the performance of desiccant air dryer
Sometimes, the operating conditions are far from the rated working conditions. In this case, it will affect the normal operation of the equipment. This prevents us from getting high quality compressed air. Furthermore, it will also affect the service life of desiccant air dryer.
① Firstly, the intake air temperature should not generally be too high. Most suction dryers are rated for an inlet air temperature of 45°C. If the temperature is too high, it will make the drying efficiency of the dryer decrease.
② Secondly, the oil content of the compressed air should be controlled. This is because the adsorbent is contraindicated to oil. If the oil content is exceeded, the adsorption performance and lifetime are greatly reduced.
③ Thirdly, the water content in the compressed air must also be controlled. If there is too much moisture, the regeneration effect will be affected. In severe cases, this can lead to chalking of the adsorbent.
How to do desiccant air dryer maintenance?
(1) Daily maintenance content of adsorption dryer:
Firstly, check and record the intake pressure, intake temperature and flow. and ensure that it is within specification;
Secondly, check whether the reading of the tower pressure gauge is within the tolerance range;
Thirdly, check the tower pressure gauge to confirm that the dryer working cycle is normal;
Fourth, check the pre-filter condensate drain valve. Confirm that it is functioning normally. Replace the filter element as soon as possible as required by the differential pressure indicator.
Fifth, ensure that the pressure in the purification tower is less than or equal to 5PSIG;
Finally, verify that the pre/post filter differential pressure is within the operating range. Change the filter element regularly.
(2) Monthly maintenance of desiccant air dryer:
Firstly, check the basic operating parameters of the dryer;
Next, check the pre/post filter differential pressure and the drain valve as well.
Thirdly, check the dryer operating cycle and sequence (ie drying, depressurization, regeneration).
(3) Quarterly maintenance of regeneration air dryer:
Firstly, swap the front/rear filter elements. Replace the filter element regularly according to the manufacturer’s recommendations;
Next, check the pilot air filter element and replace it if necessary.
(4) The maintenance of the adsorption dryer every six months:
Firstly, check the dryer exhaust dew point;
Secondly, check the heater current amperage;
Thirdly, replace the front/rear filter element.
(5) Annual maintenance of regenerative air dryer:
Firstly, check the desiccant. Replace as needed;
Secondly, check and repair various valves;
Thirdly, test the indicator lights and switches;
Fourth, test electrical components;
Finally, check for air leaks, loose bolts/flanges/joints.
(6) Desiccant air dryer maintenance every two years:
Firstly, replace the check valve;
Secondly, replace the control non-destructive discharge valve;
Thirdly, check and replace the temperature probe.
(7) Regeneration desiccant air dryer maintenance every 3 to 5 years:
Replace the desiccant beads of the adsorption dryer.
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