Refrigerated dryers RDX

Optimal performance for your compressed air: Comprag RDX refrigerated dryers

Clean, dry compressed air is essential for uninterrupted production processes and ensures the longevity of your entire plant equipment. Without proper treatment, moisture in the compressed air inevitably leads to corrosion, increased scrap, and costly maintenance.

Therefore, rely on the RDX series of refrigerated dryers from Comprag GmbH. These highly efficient refrigerated dryers ensure that your compressed air always reaches the required dew point. The RDX series dryers are robustly built, characterized by high efficiency and minimal pressure loss. Even under fluctuating load conditions from 0% to 100%, they guarantee a consistently low dew point.

Constant low dew point for efficient moisture removal even in the case of variable compressed air flow conditions.

Reliability and maximum energy efficiency

As a specialist in compressed air systems, Comprag GmbH places the highest value on achieving maximum performance with minimal operating costs. The RDX series refrigerated dryers are specifically designed to achieve this optimal balance.

Every Comprag refrigerated dryer offers you:

• Superior separation: With an integrated coalescing condensate separator , our models reliably separate up to 98% of the moisture.
• Operational reliability: Even with highly variable compressed air consumption, the robust design of Comprag GmbH guarantees maximum operational reliability.
• Low costs and pressure loss: The combination of highly efficient aluminum heat exchangers and excellent thermal insulation results in minimal pressure loss. This means your compressors consume less energy, representing a significant cost advantage.
• Precise control: Cooling output is flexibly adjusted to changing loads. The clear dew point indicator also allows you to monitor the compressed air quality at any time.

Environmental responsibility: Comprag GmbH uses state-of-the-art refrigerants in every refrigerated dryer, thus underlining its environmentally conscious design.

Areas of application: Trust in industry

Comprag's RDX refrigeration dryers are designed to meet the most stringent requirements of key industries. Your investment protects your company's entire value chain.

• Medical & Pharmaceutical: Our refrigerated dryers ensure the necessary low dew point for sensitive processes such as sterilization and packaging applications.
• Pharmaceuticals and medicine: The dryers provide the required low dew point for sensitive processes such as packaging applications and sterilization.
• Beverages and food: The reliable removal of moisture ensures that strict hygiene and quality standards are maintained during bottling.
• Surface technology and painting systems: The smallest water particles that could cause painting defects are eliminated, ensuring flawless results .
• Workshops and mechanical engineering: Corrosion protection extends the service life of your pneumatic control and tool components.

Technical innovations of the RDX series

The performance of a refrigerated dryer can be measured by its consistency and efficiency. Comprag GmbH relies on proven components in its RDX series to guarantee top technical performance.

The centerpiece: The combined heat exchanger

The energy efficiency of the RDX series is ensured by the advanced combined heat exchanger with its three functional units.

Combined 3-in-1 heat exchanger

The combined heat exchanger in an RDX refrigerated dryer consists of three functional units: an air/air heat exchanger, an air/refrigerant heat exchanger and a coalescence separator.

The air/air heat exchanger pre-cools hot compressed air. This saves up to 50% in energy in the subsequent refrigerant cooling process. At the same time, cold dry air leaving the dryer is heated to a suitable temperature for subsequent use. The air/refrigerant heat exchanger brings the temperature of the compressed air to dew point. The coalescence separator removes condensate from the compressed air. The separated condensate is periodically discharged by the condensate drain valve.

Comprag GmbH guarantees the energy efficiency of its RDX series through an advanced combined heat exchanger consisting of three functional units - the central argument for our refrigerated dryers:

1. Air-to-air heat exchanger (energy saver): It pre-cools the warm, incoming compressed air by utilizing the already cooled, dry exhaust air. This saves up to 50% energy in the subsequent refrigerant cooling process.
2. Air/refrigerant heat exchanger: Cools the air precisely to the dew point of +3 °C, causing the water to condense reliably.
3. Coalescence separator ( demister ): Removes condensate and fine oil particles from the compressed air. The collected condensate is drained regularly and with minimal loss.

The compact design of the units guarantees minimal pressure losses and maximum reliability.

The refrigeration cycle: Protection against icing

Reliable compressed air drying is based on a continuous, highly efficient refrigeration circuit. In the RDX models, this principle is perfected to keep the pressure dew point consistently above +3 °C, thus preventing icing.

Refrigerated dryers RDX-04 to RDX-77 Functional block diagram

Refrigerated dryers RDX-100 to RDX-360 Functional block diagram

• Refrigerant compressor (1): It compresses the refrigerant in its gaseous state.
• Liquefier (3): Here the compressed gas cools down and largely changes into the liquid phase.
• Filter dryer (5): Cleans the liquefied refrigerant to protect the components.
• Expansion valve (4): Regulates the flow rate and injects the refrigerant into the evaporator. In combination with the regulated circuit, it ensures that the pressure in the evaporator is kept constant, thus preventing the pressure dew point from dropping below +3 °C (freezing protection).
• Evaporator (2): Here, the refrigerant absorbs the heat from the compressed air and becomes gaseous. At this moment, the moisture from the compressed air condenses.

This cycle, supplemented by time-controlled steam traps (6), ensures maximum performance and minimum risk, regardless of the model size (from RDX-04 to RDX-360)

How to size the ideal refrigerated dryer

The performance of your Comprag RDX series depends significantly on correct sizing. We guarantee that your dryer will reliably achieve the pressure dew point of 3 °C, even under real-world conditions that deviate from the norm.

The standard volume flow rate refers to an operating pressure of 7 bar, an air inlet temperature of 35 °C, and an ambient temperature of 25 °C (according to DIN ISO 7183). Correction coefficients must be applied in case of deviations.

The Comprag formula for process reliability:

To calculate the actual required volume flow rate of the refrigerated dryer, the volume flow rate of your compressor is multiplied by the correction coefficients (F1, F2, F3):

Air volume flow compressor x F1 x F2 x F3 = air volume flow dryer

• F1 (Operating pressure): Takes into account the actual working pressure.
• F2 (Compressed air inlet): The most critical factor, which takes into account the temperature of the air entering the refrigerated dryer.
• F3 (Environment): Takes into account the ambient temperature at the installation site.

Calculation example:

Let's assume a compressor that delivers 1.6 m³/min at 4 bar, an air inlet temperature of 45 °C and an ambient temperature of 35 °C:

The calculation yields:

Air volume flow = 1.6 x 1.25 x 1.39 x 1.14 = 3.169 m³/min

In this case, a Comprag refrigerated dryer is needed that can handle at least 3.17 m³/min - a model that is significantly larger than the pure compressor capacity would suggest.

The optimal solution

An RDX series refrigerated dryer is the ideal solution for complete compressed air drying - from small workshops to large industrial plants. Rely on the robustness, quality, and performance that have proven themselves over many years. Ensure consistently high product quality and a longer service life for your tools.

With a refrigerated dryer from Comprag GmbH, you are making the right decision.