High-quality air dryer: Make the air compressor run “dry” under any working conditions

1. The close relationship between air dryer and air compressor

The air dryer plays a vital role in the whole air compressor system. During the operation of the air compressor, the water in the compressed air will condense into water vapor, and the air dryer is widely used to remove this water, improve the air quality, and ensure the operation stability of the whole system.

The air dryer consists of a compressor, heat exchanger, condenser, dryer and control system. The compressor sends compressed air into the high temperature area of the heat exchanger, uses the refrigerant in the heat exchanger to condense the moisture in the air into water, and then separates the water from the air through the condenser, and then the adsorbent in the dryer absorbs the remaining moisture to produce dry air.

The refrigerated dryer can adjust the humidity of the output dry air according to different compressed air requirements, provide a high level of air quality control, and ensure a clean atmosphere without moisture and pollutants during the production process. Its application range is very wide, including food and beverage, chemical, pharmaceutical, automotive, health, textile and other industries. Especially in the food and pharmaceutical industries, the requirements for air drying are more stringent, and refrigerated dryers have been widely used in these industries.

The use of air dryers can not only ensure the stable operation of the compressor, but also avoid damage to the compressor itself, extend its service life and reduce maintenance costs. Some advanced compressor manufacturers provide air dryers in their air compressor systems, providing customers with a total solution from the supplier’s perspective.

In summary, the air dryer plays an important role in the whole system of the air compressor. It can not only remove moisture and pollutants from the air, but also protect the compressor and ensure the stable operation of the whole system. With the advancement of industrial automation and the improvement of environmental protection requirements, the application of air dryers will continue to expand.

2. Working principle of air dryer

1. Freezing and dehumidification process

The air dryer works on the principle of freezing and dehumidification. The compressed air first enters the air dryer and is forced to cool down through the evaporator for heat exchange. In this process, the gaseous water and oil in the compressed air are cooled isobarically, and when the temperature drops to a certain level, they condense into liquid water and oil. These liquid water and oil carry dust and are discharged from the system through the automatic drain, thus obtaining clean compressed air. This process is cyclical, ensuring that the output compressed air always remains dry.

(II) Functions of main components

1. Compressor : The compressor in the dryer is the core component of the refrigeration system. It compresses the low-temperature and low-pressure gaseous refrigerant into high-temperature and high-pressure superheated refrigerant vapor. Different types of compressors have different applications, such as piston type, scroll type, rotor type, screw type, centrifugal type, etc. For example, dryers with a power of less than 3 horsepower usually use rotor type; 3 to 30 horsepower usually use full piston type; 25 to 65 horsepower is semi-piston type; 65 horsepower and above are mostly screw type.
2. Condenser : The function of the condenser is to cool and condense the superheated refrigerant vapor at high temperature and high pressure into liquid refrigerant at medium temperature and high pressure. Condensers are divided into air-cooled and water-cooled types, which can be selected according to the actual situation of the user.
3. Expansion valve : The expansion valve converts high-pressure and medium-temperature liquid refrigerant into low-pressure and low-temperature liquid refrigerant. The expansion valve is divided into internally balanced and externally balanced types. When working, its temperature sensing package is installed at the outlet of the evaporator, and automatically adjusts by sensing the return air superheat of the refrigerant.
4. Evaporator : The evaporator is the main heat exchange component of the dryer. The compressed air is forced to cool in the evaporator, and most of the water vapor is cooled and condensed into liquid water and discharged outside the machine, thereby drying the compressed air. The low-pressure refrigerant liquid undergoes a phase change in the evaporator and becomes low-pressure refrigerant vapor. During the phase change process, it absorbs the surrounding heat, thereby cooling the compressed air.

(III) Refrigeration accessory function

1. Filter drier : Filters moisture and particulate matter from the refrigerant system, removing the danger of acid formation.
2. Sight glass : On the one hand, it can be used to observe the flow of Freon and the status of the system; on the other hand, it can be used to observe whether there is water in the refrigeration system.
3. Hot gas bypass valve : used for energy regulation of the system, by bypassing the high-pressure refrigerant to the low-pressure side of the system, so as to maintain normal operation within the specified minimum suction pressure (low load) range and prevent ice blockage of the machine under low load.

3. Inventory of high-quality air dryer brands

The top ten brands of air dryers in 2024 are: YADU, DEERMA, Sheffield, SENElectric, PARKOO, Kawasima, SCIENTZ, Huashidan, Lidesheng, and Boling.

YADU : Affiliated to Beijing YADU Environmental Protection Technology Co., Ltd., it was founded in 1987 and is a famous trademark in Beijing. It provides overall solutions for indoor air quality. In the field of air dryers, its products have advanced technology and reliable quality. The brand has a variety of products such as fresh air systems, air humidifiers, air conditioning fans, air dryers, etc., showing its extensive layout in the field of environmental equipment.

DEERMA : A brand of Delma Electric Co., Ltd. in Shunde District, Foshan City, focusing on independent research and development in the field of small household appliances. The products cover many fields such as household appliances and automobile appliances. As one of its product lines, the air dryer has innovative design and excellent performance. For example, it uses an intelligent control system that can automatically adjust drying parameters according to the environment.

Steel Shield Sheffield : A brand of Hangzhou Superstar Technology Co., Ltd. and a well-known brand of hand tools. In the production of air dryers, we are famous for our exquisite craftsmanship and strict quality control. Its products are durable and efficient and suitable for various industrial scenarios.

SENElectric : A brand of Guangzhou Zhongwei Instrument Co., Ltd. and a well-known brand of artificial environment equipment of the American WGI Company. Mainly engaged in automatic environmentally friendly dehumidifiers, professional high-efficiency air purifiers and other products. air dryer products have efficient dehumidification capabilities and stable performance.

PARKOO : A brand of Guangzhou Dongao Electric Co., Ltd., a well-known dehumidifier brand. It integrates the design, research and development, production and sales of dehumidification and humidification equipment. Its air dryer products perform well in humidity control and can meet the needs of different users.

Kawasima : A brand of Changzhou Kawasima Electric Co., Ltd., a professional manufacturer of high-quality dehumidifiers. Committed to the development of high-performance air humidity regulation technology, the air dryer products use advanced condensation technology to quickly and effectively remove moisture from the air.

SCIENTZ : A brand of Ningbo SCIENTZ Biotechnology Co., Ltd., a world-renowned provider of biological sample processing equipment. The air dryer products have precise temperature control and efficient drying effect, and are suitable for laboratories and other places with high environmental requirements.

Huashidan : A brand of Chongqing Huashidan Machinery Manufacturing Co., Ltd., mainly focusing on small and medium-sized outdoor production machinery. In the field of air dryers, the products are durable and have stable performance, suitable for various complex working environments.

Lidesheng : A brand of Nanjing Lidesheng Machinery Co., Ltd., specializing in the research and development, production, sales and service of temperature control equipment. The air dryer products have an efficient refrigeration system and a reliable electronic drainer to ensure the stable operation of the equipment.

Boling : A brand of Hangzhou Boling Purification Equipment Co., Ltd., specializing in the research and development, design, manufacturing and sales of air dehumidification and humidification equipment. With a full set of production lines and testing equipment, the air dryer products have an annual production capacity of 300,000 units, with reliable product quality and stable performance.

4. How to choose a high-quality air dryer

(I) Selection according to air compressor parameters

Parameters such as air compressor exhaust volume, inlet air temperature, and pressure dew point are crucial to selecting a suitable air dryer. First of all, the compressed air processing capacity of the air dryer should be similar to the volumetric flow rate of the air compressor. This can ensure that the two can significantly save energy and operating costs when the working pressure is equivalent. For example, when the gas production volume of the air compressor reaches a certain value, we can appropriately select and add a model of air dryer to match. At the same time, the intake air temperature is also an important consideration. The air inlet temperature of different air compressors may be different, and the refrigerated dryer needs to be adjusted according to this temperature to ensure that it can effectively condense the moisture in the air. Generally speaking, the higher the inlet air temperature, the stronger the cooling capacity required by the refrigeration dryer. In addition, pressure dew point is also one of the key factors in selecting a air dryer. Pressure dew point refers to the temperature at which water vapor in the air begins to condense into liquid water under a certain pressure. If the pressure dew point of the refrigerated dryer is set improperly, the moisture in the air may not be completely removed, thus affecting the quality of the compressed air. Therefore, when selecting a air dryer, we need to comprehensively consider factors such as exhaust volume, inlet air temperature, pressure dew point and other factors based on the actual working conditions of the air compressor to ensure that a suitable air dryer is selected. If you do not know the specific conditions of the air compressor, be sure to ask a professional air compressor technician to select the type for you based on the on-site gas consumption of the air compressor.

2. Consider volume and weight

Many users think that the larger the size of the air dryer, the better the effect, but this understanding is biased. With the development of science, products with good effects can also be small in size and light in weight. A air dryer that really suits the needs is not determined by the size or weight. What users want to buy is the effect rather than the size and weight. Heavy mechanical equipment has been produced in my country for decades and has continued to this day, while it has long been replaced by new technologies in developed countries. It is not difficult for our people to make any product with traditional technology, but it is not easy to catch up with or surpass the manufacturing technology of developed countries in terms of technological innovation. As long as we adopt new technologies and high-quality raw materials, we can also make good products with small size and light weight. For example, some advanced air dryers on the market now use new materials and technologies. They are not only small in size and light in weight, but also have efficient dehumidification capabilities and stable performance.

3. Focus on internal configuration

The quality of the air dryer depends on the quality of the raw materials. Nowadays, the materials in the air compressor market are mixed, and the sources of the channels are unknown. Therefore, only by choosing a big brand, a reputable, and a large-scale merchant can the product have quality assurance. The internal configuration of the air dryer is a key factor affecting its quality and performance. For example, the core component of the air dryer is the compressor, and the quality of the compressor affects the drying effect and service life. The products of large manufacturers generally choose more well-known compressor brands such as Panasonic, Hanbell, and Copeland, which are more secure to use and reduce the worries of equipment failure. In addition, other internal configurations such as heat exchangers and dryers also need to use high-quality materials to ensure the performance and reliability of the air dryer. When choosing a air dryer, the key is to see whether its internal configuration uses today’s advanced materials, which is crucial.

5. air dryer allows air compressor to operate under different working conditions

 

1. Winter operation strategy

In winter, due to the low temperature, the use of compressed air refrigeration dryers may be subject to certain restrictions. As mentioned earlier, refrigeration dryers use refrigerants to reduce the temperature of compressed air to achieve a drying effect, but the refrigerant cannot reduce the temperature infinitely and can only reduce the temperature to 2-3°C at most. In the northern region where the temperature reaches below zero degrees Celsius in winter, the dried compressed air will once again precipitate liquid water in the pipeline due to the influence of the external ambient temperature, and liquid water is easy to freeze at 0°C, which is prone to ice blockage.

In contrast, compressed air adsorption dryers have more advantages in winter. Adsorption dryers can easily process the pressure dew point of compressed air to a temperature below the freezing point of water, with good drying effect and a much higher degree of drying than air dryers, without producing liquid water.

Therefore, when the temperature is below zero degrees Celsius, it is recommended not to use a compressed air refrigeration dryer. You can use an adsorption dryer instead to ensure the drying and dehydration effect of the compressed air and avoid problems such as pipe icing and blockage.

(II) Summer operation measures

High temperatures in summer pose many challenges to the normal operation of air compressors. Here are some ways to ensure the normal operation of air compressors and the role of refrigerated dryers in it.

1. Change the lubricating oil

High temperatures and humidity can reduce the life of lubricating oil by more than half. Compressor oil has key functions such as lubricating rotors and bearings, absorbing/removing heat generated by compression, sealing for efficient compression, preventing metal-to-metal contact, and removing particulate contaminants. Scheduled oil and filter changes maintain proper viscosity for better lubrication and remove moisture, acids, wear metals, and other contaminants. Change oil and filters before the start of summer to keep your compressor running better. At the same time, performing lubricating oil analysis can detect problems before they cause expensive repairs and downtime.

2. Check the lubrication oil system

To ensure proper cooling and lubrication and prevent unplanned downtime, make sure there is no problem with the lubricating oil circulation of the air compressor. Good lubricating oil circulation can effectively reduce the operating temperature of the air compressor and improve its working efficiency.

3. Replace the intake air filter

Replacing the intake air filter on a scheduled basis maintains compression efficiency and maintains proper operating temperature. Replacing the air filter also keeps the lubricating oil cleaner longer, providing better protection for the rotor. In the summer, the air filter is easily clogged by pollutants such as dust and pollen, affecting the air intake quality and efficiency of the air compressor. Therefore, it is crucial to replace the intake air filter regularly.

4. Keep the dryer cooler clean

Keep the lubricating oil and aftercooler clean to keep the operating and compressed air outlet temperatures as low as possible. This will make the dryer more effective and extend the life of the oil. In the summer, the cooler is easily clogged by dust, debris, etc., affecting its heat dissipation effect. Therefore, clean the cooler regularly to ensure its normal operation. Replace or clean the cooler filter pad if any. In the summer, keeping the cooler clean is one of the most important things to ensure the normal operation of the air compressor.

In addition, other measures can be taken to ensure the normal operation of the air compressor in summer, such as ventilating the air compressor room, checking the belts and couplings, cleaning the electrical cabinet, etc. By taking these measures in combination, the operating temperature of the air compressor can be effectively reduced, its working efficiency can be improved, and the stable operation of the compressed air system can be ensured.