In order for the compressed air system to operate normally, the air must be dry. This means that before entering the air network, there must be no liquid moisture in the air and the relative humidity must be low. Different methods can be used to remove water from compressed air, which will help maintain high air quality. One of the mainstream equipment used to dry compressed air is the refrigeration dryer, which can be divided into fixed frequency or variable frequency.

1. What is a refrigerated dryer?

As the name implies, a refrigerated dryer cools compressed air. This makes the water in the compressed air condense and separate from the air itself. It is a vital air system component for applications that need to dry the compressed air to a low dew point.

In the first stage, the compressed air enters the dryer and passes through the air to the air heat exchanger, which pre cools the incoming air.

In the second stage, the compressed air enters the refrigerant heat exchanger through the air, reducing the dew point of the compressed air to 3 ° C/37 ° F. The water vapor in the air condenses into a liquid, which is captured and removed. The dry air is then heated in a heat exchanger to reduce the relative humidity in the air; This prevents the formation of condensate in the downstream piping.

2. What is the difference between fixed frequency dryer and variable frequency dryer?

In fixed frequency dryer, the refrigerant compressor runs continuously. Because the ambient temperature and compressed air flow will change, a bypass valve is usually used to regulate the temperature of the refrigerant and prevent freezing operating conditions in the system. The traditional refrigerant air dryer usually uses a piston compressor running at a fixed speed. In terms of energy efficiency, this leads to the same "on or off" disadvantage in fixed speed air compressors.

In contrast, the variable frequency cold dryer uses a scroll compressor, with a spiral element of the scroll compressor running around the second fixed element. It is compact and quiet, and the inverter driving the rolling element can change the speed to meet the demand, thus saving energy.

3.If I have a variable frequency compressor, should I choose a variable frequency dryer? If I have a fixed frequency compressor, do I need a fixed frequency dryer?

For processes with constant compressed air demand, fixed speed compressors and fixed speed dryers can cost-effectively provide the required air. For processes where compressed air demand varies with factors such as process, workload or shift, a variable frequency compressor can match compressed air production to demand. While a fixed speed dryer can be sized for the maximum output of a variable frequency compressor, the ability of a variable frequency dryer to match dryer energy consumption to air demand can also result in significant savings in energy and operating costs.