Design
About the author
Mehul Mehta is the Founder and Managing Director of Kinam Engineering Limited. Mehul is on a mission to change the way industries perceive heat exchangers— not as commodities but as drive efficiency and profitability. Backed by relentless R & D, innovation, and a commitment to performance, Mehta ensures Kinam delivers cutting-edge solutions that move industries forward. He champions precision-engineered heat exchangers that optimize industrial processes, delivering measurable gains and a clear path to global leadership. factors include pumping power to keep the flow smooth. The points that matter for a successful design are dependent on the following principles:
• Heat exchangers need proper allowable pressure drop in the presence of fouling. It should be operational until the next maintenance period of the heat exchanger without reduction in the process stream flow.
• The design of the equipment should bear the service conditions prevalent in the plant environment.
• The configuration of the exchanger should be such that any part can be replaced which undergoes erosion, cleaning, or replacement. It should be strong enough to resist vibrations or aging after long usage.
• It is up to the designer to make provision for flexible piping and valves with a multiple and advantageous arrangement.
• One unit can be isolated for maintenance without disturbing the other parts and the operational plant.
• The entire equipment should be cost-effective for the client considering the requirements.
• If there are limitations of the plant, the configuration should be created to suit the lifting and servicing capabilities.
Furthermore, the focus must be on the following queries related to the design and its impact on operations:
Is the flow rate also affected by a higher pressure drop? Yes, higher pressure loss means higher head required for pump and if pump is not designed for higher head, it will result in reduction in flow rate.
Why curtailing fouling is equally significant to pressure drop? Fouling means deposition and accumulation of unwanted materials such as scale, insoluble salts, algae, solids etc., on the heat transfer surface, at no stage is fouling desirable in any heat exchanger. It gets deposited in the shell / tube side and is also prone to leakages. Fouling also leads to higher corrosion and premature failure of the equipment. Because of fouling, pressure drop across the heat exchanger increases significantly and reduces thermal performance of the exchanger. In order to preserve the long-lasting life of the heat exchanger, regular cleaning of the deposition should be done. There are many other reasons for fouling and that needs to be considered depending on the industrial usage and application.
Conclusion In the selection and design of heat exchanger, pressure drop plays a vital role. Pressure drop also affects the operational cost and capital investment. Lower pressure drop means lower operational cost and higher capital investment, and vice-versa.
36 Heat Exchanger World April 2025 www. heat-exchanger-world. com