Filmwise & Dropwise Condensation

Product Code: AL-HT-CD-01

1. Overview

The Atto Labware India Filmwise & Dropwise Condensation Apparatus is a state-of-the-art experimental platform specifically engineered to meet the rigorous demands of engineering colleges, polytechnics, and TVET (Technical and Vocational Education and Training) institutions. This apparatus provides students with a visual and quantitative understanding of the fundamental heat transfer mechanisms involved in phase-change processes.

In thermal engineering, condensation is a critical process in power plants, refrigeration, and chemical manufacturing. This system allows users to clearly distinguish between two primary modes: Filmwise Condensation and Dropwise Condensation, facilitating comprehensive laboratory study on heat transfer coefficients and surface efficiency.

2. Working Principle

The apparatus operates on the principle of controlled steam condensation onto a metal surface cooled by a circulating water flow.

Filmwise Condensation This mode occurs on clean, high-energy surfaces. The condensate forms a continuous liquid film that covers the entire surface area. This film acts as an additional thermal resistance, significantly reducing the overall heat transfer coefficient between the steam and the cooling surface. Students can observe this continuous layer forming and flowing downward due to gravity.

Dropwise Condensation When the surface energy of the condenser is reduced—typically through the application of a hydrophobic promoter (such as Oleic acid or a PTFE-based coating)—the condensate beads up into discrete droplets rather than forming a film. These droplets grow and roll off the surface, constantly exposing the bare metal surface to the incoming steam. Because the surface remains largely uncovered, the heat transfer coefficient is significantly higher—often an order of magnitude higher—than that of filmwise condensation.

3. Key Features & Benefits

• Modular Design: Engineered with interchangeable condenser specimens, allowing for a seamless transition between filmwise and dropwise experiments.

• Visual Analysis: A high-temperature resistant tempered glass observation chamber provides students with a clear, direct view of condensation dynamics.

• Educational Alignment: Designed to fit the syllabus of mechanical, chemical, and energy engineering curricula in polytechnics and universities.

• Precision Instrumentation: Includes integrated digital temperature sensors and flow meters, enabling real-time data acquisition for students to calculate experimental heat transfer coefficients.

4. Technical Specifications

Parameter	Specification
Steam Generator	2.0 kW Integrated Electric Boiler
Observation Chamber	Borosilicate Tempered Glass
Condenser Material	High-Conductivity Polished Copper
Cooling Medium	Water Circulation
Temperature Control	PID Digital Temperature Controller
Data Output	Digital Display & Optional USB/PC Interface

5. Experimental Scope

This unit enables students to conduct the following experiments:

• Visual demonstration and characterization of filmwise vs. dropwise condensation.

• Determination of the overall heat transfer coefficient (U) for both modes.

• Calculation of the convective heat transfer coefficient.

• Study of the impact of cooling water flow rates on condensation rates.

• Evaluation of the influence of surface hydrophobic coatings on thermal performance.

6. Safety & Maintenance

At Atto Labware India, safety is paramount. The unit includes a dedicated pressure relief valve for the steam boiler and low-water-level protection to prevent overheating. The modular condenser design facilitates simple maintenance; simply unscrew the specimen, clean or re-apply the coating, and re-install for the next lab session.

Atto Labware India is committed to advancing technical education globally, providing robust, precise, and reliable tools for the next generation of engineers and technicians.