Kaltra - Brazed Aluminium Microchannel Evaporators

In addition to advanced protective treatments against corrosion—such as electrophoretic epoxy coating, trivalent chromium coating, and nanoscale trichrome film—as well as UV protection, we offer performance-enhancing topcoats. These include hydrophilic and hydrophobic coatings that assist in condensation management, improving coil performance and efficiency, particularly under wet or freezing conditions.

With these topcoats applied, coil surfaces resist water adsorption and wetting, allowing water to flow effortlessly off the heat exchanger surface due to reduced surface tension. This results in enhanced heat transfer performance, especially in wet and frost conditions.

Uniform refrigerant distribution across microchannel tubes plays a crucial role in ensuring efficient evaporator operation. To achieve optimal two-phase flow distribution and prevent the formation of superheated regions, advanced techniques and specialized coil geometries are implemented, including:

• In-built direct expansion (DX) refrigerant distributors
• Optimized width-to-height ratios
• Precisely quantified inlet-to-outlet manifold sectional areas
• Hydraulic diameter optimization of ports
• Flash gas separation and bypassing

The primary function of the refrigerant distributor integrated into the inlet manifold of the evaporator coil is to ensure uniform refrigerant distribution across the microchannel tubes, optimizing performance across a wide range of operating conditions and equipment designs. The distributor achieves this by:

1. Separating liquid and gas phases within the refrigerant mixture before distribution
2. Injecting liquid refrigerant into distributor orifices, generating the necessary pressure drop to propel the refrigerant and achieve even distribution along the inlet manifold
3. Delivering liquid refrigerant precisely into individual tube chambers
4. Preventing refrigerant flow between tube chambers prior to entering the microchannel tube ports