Everyone is aware that atmospheric air constantly contains moisture, even when we cannot see it. A compressed air system effectively cools the air below its dew point when it compresses it. Additionally, it turns it into liquid water. This procedure poses a problem since the compressed air system totally relies on dry air and cannot operate as intended if there is moisture in the air. To be particular, air must not include any sort of liquid moisture. To stop corrosion inside the system, it must be at a relative humidity of less than 50%. Air compressor manufacturers in Ahmedabad always recommend removing the moisture from the compressed air systems to enhance the compressor’s life.
In this article, we will discuss the removal process of moisture from the compressed air systems in detail.
Problems caused by Moisture
Moisture in compressed air used in manufacturing plants creates difficulties with pneumatic systems, solenoid valves, and air motors, as well as affecting the production process or product. Moisture issues in compressed air lines were just accepted as unavoidable for many years. Following problems can occur due to moisture in the compressed air systems
- As it wipes away lubrication, it causes corrosion and increased wear of moving components in industrial machinery.
- Paint sprayed using compressed air can have a negative impact on colour, adhesion, and finish.
- Process industries, where numerous processes rely on the effective operation of pneumatic controls, may be jeopardised. Due to corrosion, scale, and blocked orifices, these controls might fail, resulting in product damage or costly shutdowns.
- In cold conditions, control wires might freeze, resulting in incorrect control functioning.
- Corrosion of air or gas-operated equipment, erroneous readings, and interruption or shutdown of plant activities are all possible outcomes.
Techniques of moisture removal from compressed air systems
There are various techniques with the help of which the moisture can be completely removed from the compressed air systems. These are discussed below in detail
Cooling Plus Separation
Water condenses in significant amounts as the heated, compressed air cools. This separation requires condensation, which is challenging. An after cooler is the best option to separate vapour from the large amount of air. Even heat exchangers function if they need to cool hot pressurised air. Instead of condensation, it causes the water to precipitate. Refrigerated dryers perform this task flawlessly.
Over-compression
The air is compressed to a greater pressure throughout this operation than is actually required. It exceeds the intended operating pressure by a wide margin. Air returns to the pressure needed for the job after separation. Over-compression is appropriate given the high energy required by the work technique. When airflow rates are lower, the technique is effective.
Membrane Drying
Gases in the air separate the water vapour by selective penetration. Wet, filtered compressed air condenses on the fibers as it enters the cylinder, creating water vapour. Simultaneously, the dry hair constantly passes through those fibers
Absorption drying
Chemicals like sulfuric acid or sodium chloride are used in this operation. These compounds become bonded to this process whenever water vapour is in close proximity to them. Solid or liquid substances can be used as absorbent materials. Additionally, they are widely used and readily accessible.
Adsorption Drying
In this procedure, the flow of wet air is dried using a hygroscopic or dry substance. Some of the most often utilised materials include activated alumina, silica gel, and molecular sieves. Purge regenerated adsorption dryers, heated purge regenerated dryers, blower regenerated dryers, and heat of compression dryers are examples of dryers that operate in this manner.
