SELECTION OF AIR DRYER

Air Dryer Selection Guide: Essential Data and Key Points Explained

The data required for selecting an air dryer includes the following:

1. Air Compressor Capacity (HP/kW): The capacity of the air compressor that will be used.

2. Required Dew Point Temperature (℃): The dew point is the temperature below which condensation will not occur in compressed air. For refrigerated dryers, a general guideline is around 10°C. Depending on the application, drier temperatures of 3°C or 5°C may be necessary.

3. Inlet Air Temperature to the Dryer (℃): This refers to the temperature of the compressed air as it enters the air dryer. It can vary based on the type of air compressor (water-cooled or air-cooled) and the installation environment (ambient temperature, location of the receiver tank, etc.). It is advantageous to lower the temperature as much as possible before reaching the dryer, which is why receiver tanks are often installed before the dryer. This allows for some water droplets to be removed prior to entering the dryer.

4. Ambient Temperature (℃): The temperature of the environment where the air dryer is installed. In Thailand, it is essential to base this selection on the hottest period of the year. Additionally, if the dryer is installed in the same room as the air compressor, the heat generated by the compressor can significantly raise the room temperature, so this must also be taken into account.

The catalog performance values are based on rated conditions. Ideally, the specific operating conditions of the user should be used to calculate any performance degradation, and a selection with additional capacity should be made to ensure sufficient performance.

Under severer conditions, processing capacity will decrease accordingly.

Key Considerations for Air Dryer Selection in Thailand:
Risks of Insufficient Capacity

In Thailand, it is often observed that suppliers select air dryer models that are deliberately marginal or slightly under-capacity. In most cases, several companies participate in bidding for compressed air systems, and to make their proposals more favorable, they tend to choose smaller models that do not meet the necessary capacity requirements.
While such selections may work well during cooler periods, issues can arise during hotter months. Specifically, insufficient capacity may prevent the dew point from dropping adequately, leading to drainage problems in the manufacturing environment.
Additionally, the capacity of refrigerated air dryers tends to diminish over several years of use. A model that was initially sufficient may become inadequate after a few years, resulting in performance issues.

When making a selection, choose a model with a slightly higher capacity than the required performance to ensure adequate operation.

How to Accurately Select an Air Dryer: Selection Simulation

Using an air dryer with insufficient capacity can prevent the dew point from being lowered to the required level, resulting in drainage issues in the manufacturing environment. Additionally, using a model without sufficient capacity may lead to a decline in performance due to degradation after a few years, further contributing to drainage problems.

When purchasing an air dryer, it is essential to check the **"selection basis"** and ensure that accurate data applicable to the actual working environment is being used. Also, confirm that the dryer has sufficient capacity for long-term use in the future.