Finned Tube Heat Exchanger for Process Exhaust Gas Condensation and Waste Heat Recovery

Finned Tube Heat Exchanger for Process Exhaust Gas Condensation and Waste Heat Recovery

Process exhaust gases often contain large amounts of heat energy and valuable substances. Through condensation and waste heat recovery, these energies can be effectively utilized, and at the same time, some of the components in the exhaust gas can be recovered, achieving the dual purpose of energy saving and environmental protection. For example, in the chemical and pharmaceutical industries, the process exhaust gas may contain organic solvents, water vapor and other components, condensation and recovery of these components can not only reduce the pollution of the environment, but also reuse the recovered substances. And waste heat recovery can be used to preheat raw materials, heat water or air, etc., to reduce the energy consumption of the enterprise.

Structure and working principle of finned tube heat exchanger

Structural Characteristics

Finned tube heat exchanger is mainly composed of finned tube, tube plate, shell, header and inlet and outlet receiver. The finned tube is the core component, and the fins are usually welded on the outer surface of the base tube, which is usually a metal tube, such as steel tube, copper tube and so on. The fins have various shapes, such as round, rectangular, etc. The material can also be selected according to the actual needs, such as aluminum fins, stainless steel fins, etc.

Working Principle

When the process exhaust gas enters one side of the finned tube heat exchanger (usually the tube range), the heat in the exhaust gas is transferred to the medium on the other side (usually the shell range) through the walls of the fins and the base tube. If used for condensation, the cooling medium in the shell stroke (e.g., water or refrigerant) causes the water vapor or other condensable components in the exhaust gases to condense into a liquid, resulting in the recovery of material and transfer of heat. For example, in a chemical process exhaust treatment, the temperature of the exhaust gas is 120 ℃, containing water vapor and organic vapors. When passing through the finned tube heat exchanger, the cooling water outside the tube cools the exhaust gas to 40 ℃, and the water vapor and part of the organic vapors are condensed down, while the heat is taken away by the cooling water.

Advantages of Finned Tube Heat Exchanger in Process Exhaust Gas Treatment

Enhanced heat transfer performance

The presence of fins greatly increases the heat transfer area of the heat exchanger. The heat transfer coefficient of a finned tube heat exchanger can be increased by several times compared to a light tube heat exchanger. This allows finned tube heat exchangers to be smaller and more compact for the same heat transfer task. For example, when dealing with larger flow rates and higher temperatures of process exhaust gases, finned tube heat exchangers are able to transfer heat more efficiently and meet process requirements.

Adaptable to a wide range of process exhaust gases

The finned tube material, fin shape and spacing can be flexibly selected according to the composition, temperature, pressure and other parameters of the process exhaust gas. For the exhaust gas containing corrosive components, corrosion-resistant materials can be used to make the finned tube; for the exhaust gas that is easy to be blocked, the fin spacing can be increased appropriately. This flexibility allows the finned tube heat exchanger to be widely used in different industrial fields and process exhaust gas treatment scenarios.

Operational Stability

Finned tube heat exchangers are relatively simple in structure and highly reliable. Under normal operating conditions, the heat exchanger can work stably for a long time as long as the flow rate, temperature and other parameters of the import and export media are stabilized. And in the event of local failure (such as a small amount of fin damage), generally does not lead to complete failure of the entire heat exchanger, with a certain degree of fault tolerance.