The cold dryer is a device that deeply freezes and dehumidifies high-pressure compressed air while performing a secondary filtration, resulting in high-quality compressed air that is low in temperature, dry, and clean. Compressed air with a saturation temperature equal to or less than 80℃ enters the pre-cooler of the dryer, where it undergoes heat exchange with ambient air. A portion of the heat from the high-temperature compressed air is carried away by the pre-cooling fan. The pre-cooled compressed air then enters the front evaporator of the refrigeration system, where it undergoes a second heat exchange with refrigerant vapor. This process lowers its temperature to nearly the evaporation temperature of the refrigerant. The air then flows through a pre-filter, removing a significant amount of liquid water, oil mist, and dust.
Clean compressed air enters the rear evaporator for further cooling, and subsequently passes through a rear precision filter, thoroughly eliminating liquid water, oil mist, and dust.
Modern industries have various requirements for compressed air, which can be categorized as follows:
Pressure and Flow Requirements:
Determine the necessary compressed air pressure and flow rate. These factors are essential for selecting appropriately sized compressed air equipment.
Dryness Requirements (Moisture Content or Dew Point Temperature):
Assess the level of dryness required. Different applications demand specific dryness levels to prevent moisture-related issues.
Cleanliness Requirements (Including Solids, Oil Mist, Microorganisms, and Harmful Gases):
Evaluate the desired level of cleanliness, which encompasses various contaminants. This includes solid particles, oil mist, microorganisms, harmful gases, and more.
By considering these factors, you can make an informed choice when selecting compressed air purification equipment that meets the specific needs of your industry.
Common refrigerated dryers are classified based on the cooling method of the condenser into air-cooled and water-cooled types. They are categorized by the inlet air temperature into high-temperature inlet type (below 80℃) and ambient temperature inlet type (around 40℃). Based on the operating pressure, there are standard models (0.3-1.0MPa) as well as medium and high-pressure models (above 1.2MPa). Additionally, many specialized specifications of refrigerated dryers can be utilized for treating non-air media such as carbon dioxide, hydrogen, natural gas, blast furnace gas, nitrogen, and more.
Utilizing an external rotor fan, the airflow is more robust, enhancing condensation and pre-cooling efficiency. This results in a more stable and reliable overall operation.
