Desiccant Air Dryer / Desiccant Dryer For Air Compressor
Technical Specifications of Lingyu Desiccant Air Dryer
| Suitable medium | Compressed air / non-corrosive air |
| Working principle | PSA + TSA |
| Adsorption air dryer type | heatless, heated, blower purge, hoc |
| Structure type | twin tower and modular |
| Working period | ≈10 min (adjustable) (for heatless desiccant compressed air dryer) |
| Average consumption of regeneration air | Std.13% | Min. 8% Max.14% (for heatless air dryer) |
| Inlet air capacity | Std.50 CFM to Max 10500 CFM |
| Inlet air pressure | Std.7 bar | Min 6 bar Max:100 bar |
| Inlet air temperature | 10～30℃ | Min.2℃ Max.40℃ |
| Ambient temperature | Min.2℃ Max.45℃ |
| Pressure loss / drop under full load | 0.2 bar |
| Inlet air dew point requirement | ≤15℃ (for heatless and heated regeneration air dryer) |
| Outlet dew point | (-20℃, -40℃, -70℃) |
| Inlet air oil requirement | Oil-free compressed air or ≤0.1ppm (mg/m3) |
| Voltage | 220V, 380V, 400V, 415V, 440V, 50~60Hz, 1-phase or 3-phase |
| Available color | gray, blue and yellow |
Kind note: we can customize the medium and high pressure desiccant air dryers. Such as 25 bar, 40 bar, 50 bar, 60bar, 70bar, 80bar, 90 bar, 100 bar.
Why Choose Us As Your Desiccant Air Dryer Manufacturer
We are one of the most professional desiccant air dryer manufacturers in China. Besides, our dryers often serve customers together with world-famous compressor brands. Our absorption dryers have the following advantages.
Strong Customization Capability
There are all kinds of regenerative air dryers available. So we can meet the various needs of customers. Besides, our factory is good at customizing large-capacity dryers. It can be up to 300 m³/min.
Adopt Long-process Design
It ensures a long contact time between adsorbent and compressed air. They have high-efficiency mufflers. So the noise is as low as 60 decibels.
Airflow Distribution Structure
The device is at the bottom of the drying tower. Compressed air enters the adsorption tower. It slows down and spread first. To ensure a uniform flow through the desiccant beads.
Using High-quality Customized Adsorbents
The particle size is 3~5mm. And water resistance is good. They will not crack or swell when in water. The adsorbent has a long service life.
Stable Outlet Dew Point
Our air desiccant dryers are filled with adequate beads. 20~24kg of adsorbent per m3/min air capacity. So it increases contact time with desiccant.
With Multiple Protection Devices
They have high and low voltage protection. The former prevents the refrigerant pressure from being too high. The latter prevents refrigerant leakage. So it can protect the compressor.
How to Choose A Desiccant Dryer For Air Compressor?
1. Basic Parameters of Adsorption Dryer
① Air Capacity
The air capacity is generally the same as that of the refrigerated dryer. We are a professional desiccant air dryer manufacturer. The maximum processing capacity can be 300m³/min. So it can meet most of the needs of customers.
② Inlet Air Temperature
As can be seen from the chart below: under the same pressure, the water content increases by 30% for every 5°C increase in the inlet temperature. The moisture load entering the dryer will increase by 30%. Besides, the adsorption capacity of the adsorbent decreases with temperature up.
Therefore, we need to reduce the inlet temperature as much as possible. At the same time, it increases liquid water filtration efficiency. Otherwise, it is necessary to add the air capacity of the desiccant dryer. That is, choose a larger model.
③ Working Pressure
According to the graph above, water content and pressure are inversely proportional. So the lower the working pressure, the higher the dryer load.
In addition, a drop in pressure results in a reduction in the amount of regeneration air. This will reduce the efficiency of the desiccant compressed air dryer.
And we can also produce high-pressure adsorption air dryers. The max pressure can be up to 100 bar.
④ Dew Point
The water content of compressed air is divided into 6 grades. Among them, the pressure dew points of grades 1 to 3 are all below -20 °C. Therefore, it must use an adsorption dryer to achieve this.
Its typical application fields are as follows. For example, photographic film, microelectronic chips (grade 1, -70°C); precision spraying (grade 2, -40°C); powder product conveying (grade 3, -20°C), etc.
In principle, install a refrigerated dryer in front to reach a -70°C dew point. Otherwise, it is difficult to guarantee the water removal effect for the absorption dryer.
⑤ Oil Content of Compressed Air
Absorbent avoids oil. Therefore, desiccant compressed air dryer has a strict limit on the oil content. Generally, it needs oil-free compressed air or ≤0.1ppm (mg/m3). Otherwise, the desiccant beads' life will be shortened. And the water removal effect will also be affected.
In particular, the HOC dryer must require oil-free air. So we usually use a HOC dryer after centrifugal or oil-free screw air compressor.
2. Regeneration Method Or Energy Saving Requirements
Often, energy savings and dew points cannot be compromised. The heatless adsorption dryer has about 13% air loss. And heated desiccant air dryer has about 6% air loss. But the blower purge is heated, and the HOC dryer can realize zero air loss
Therefore, the zero air loss desiccant dryer has high energy-saving efficiency. Although expensive, it can save a lot of electricity or water bills every year. Almost a year of savings can be enough to buy a new machine.
Of course, there are prerequisites for choosing a HOC dryer. The inlet temperature must be above 110°C. Otherwise, the energy saving will be greatly reduced. Currently, the zero air loss HOC dryer is inferior to the micro air loss HOC dryer.
3. Other Factors
① Floor Area And Shipping
Generally, the size of the adsorption air dryer is relatively large. Especially the large capacity air desiccant dryer. Therefore, the area and transportation costs are relatively big. You can choose a modular adsorption dryer if the floor space is limited.
In addition, we also have a combination air dryer. That is, the refrigerated dryer and absorption dryer are integrated. It can save floor space. Moreover, it is easy to install. And drying effect is also perfect.
② Material
Some industries have requirements for the material of adsorption dryers. They have to be 304 stainless steel. For example, pharmaceutical, food, lithium battery industries, etc.
Activated alumina and molecular sieves are common desiccant beads. Both have strong adsorption capacity for water vapor.
Activated alumina has many excellent properties. Therefore, it is the first choice for adsorption dryers on most occasions. Especially when the dew point requirement is not high.
However, the adsorption capacity in a low moisture environment is far inferior to molecular sieves. So to obtain a lower dew point, it requires molecular sieves. But its mechanical strength and water drop resistance are not ideal. Thus, we usually use it together with alumina.
For example, these two adsorbents are used together for -40°C and -70°C dryers. Just the specific proportions are different.
FAQs
How to Change Desiccant Deads in Air Dryers?
- Each drying tower has a filling port and a discharge port. So first take off the cover plate on them.
- We can insert a small stick into the discharge port. Therefore, it will help the desiccant flow out of the tower.
- There are coarse filter meshes on the tower's inlet and exhaust pipe joints. They are removable. So we can remove and clean them.
- After cleaning the coarse filter, re-install it. Then close the drain plug again.
- Remove all filler plugs. Then inject the appropriate grade and specification of desiccant beads. The adsorbent height level should meet the regulations.
- Once the two towers are filled, re-plug the filling port.
- Leak test should be carried out on all disturbed joints. Then re-commission the desiccant compressed air dryer.
Which Desiccant is Used in Compressed Air Dryers?
There are mainly two kinds of desiccant beads in adsorption dryers. That is activated alumina and molecular sieves. Generally, they are 3~5mm. In addition, different dew point requirements and different adsorbents.
For example, the -20℃ dew point dryer only needs activated alumina. But the absorption dryer above -40 ℃ is different. It must use alumina and molecular sieve together. In this way, it can achieve the effect of deep water removal.
How Long Does Air Dryer Desiccant Last?
The replacement cycle of the adsorbent is generally every two years. Of course, we have to do good maintenance work. We must install the oil removal filter because the desiccant beads are susceptible to oil.
Moreover, we have to clean and replace the filter element regularly. Otherwise, oil vapors will enter the desiccant compressed air dryer. Ultimately, it will reduce the adsorbent lifetime.
Membrane Air Dryer vs. Desiccant
Their working principles are different. Twin tower desiccant dryer mainly uses the PSA principle. And the adsorbent has a strong water absorption performance. So it can achieve low dew points.
Compressed air enters the membrane dryer. Firstly pass through a bundle of fiber tubes. Water vapor can permeate through these membranes. Then diffuse to the outside of the film layer.
And small compressed air is released through the needle valve. Expansion and decompression. The relative humidity of the backflush air drops sharply. The backflush airflow and the intake air move in the opposite direction.
There is a difference in humidity between compressed air and blowback air. Therefore, the moisture diffuses to the fiber tube. These water vapors are discharged with backflush air. Finally, we get dry compressed air.
What is The Effect of Ambient Temperature on Adsorption Dryer?
1) Influence of high ambient temperature:
- Firstly, it will cause the air compressor discharge temperature to be too high. Humidity can also be too high. So the desiccant compressed air dryer is overloaded.
- The adsorption dryer has many IC circuits. When the ambient temperature is too high, it can easily cause inaccurate control. In severe cases, circuit components will be damaged.
2) Influence of low ambient temperature:
- The regenerative exhaust air carries a lot of moisture. So it will condense or even freeze during the discharge process. The regeneration exhaust passage will be blocked. Eventually, the working procedure of the adsorption dryer will be confused.
In particular, the muffler is most prone to ice blockage. Therefore, pay attention to maintenance. - In addition, if the ambient temperature is too low, the desorption of a heatless dryer will be difficult. Adsorption heat loss is too large.
Therefore, we must consider the ambient temperature when selecting a desiccant compressed air dryer.
Is It Necessary to Have A Refrigerated Dryer Before The Regenerative Air Dryer?
Installing a refrigerated dryer in front of the desiccant dryer is unnecessary. The refrigerant dryer is unsuitable when the ambient temperature is lower than 2°C. We can only rely on the role of the adsorption air dryer. In addition, if the rear cooler of the air compressor has a good effect, sometimes it also doesn’t need to install a refrigeration dryer. However, in most cases, there requires a refrigerated air dryer. Moreover, it can bring many benefits.
Firstly, the refrigerant dryer can protect the adsorbent.
The desiccant air dryer is filled with alumina and molecular sieves. These desiccant beads mainly adsorb gaseous water. If there is no refrigeration dryer, there will be a lot of condensed water. Absorption of liquid water can cause pulverization of the adsorbent. Besides, the refrigerant dryer can also remove part of the oil. It will reduce the pollution of oil impurities in the desiccant beads. Therefore, it can extend the adsorbent replacement time.
Secondly, the refrigerated dryer can improve the dew point of the adsorption air dryer.
Freeze dryers are generally used for pre-cooling. The outlet air temperature of the air compressor is extremely high. So it requires cooling treatment. Otherwise, it will be difficult for the desiccant dryer to reach the pressure dew point required by production. Moreover, it can reduce the load on the regenerative air dryer. Therefore, it will use less consumption of regeneration air. The economic consumption of regeneration air is higher than the electricity consumption of the refrigerant dryer.
As we all know, pharmaceutical, food, spraying, and other industries generally have high requirements for production air. If only install the refrigerant dryer, it may not meet the requirements. Refrigerated dryers help cool the compressed air. Removes most of the liquid water. So it can maximize the drying effect of the adsorption desiccant air dryer. Even it can achieve a dew point of -70°C.
