Coiled Condenser

Tube-in-tube condenser structure
The tube bundle condenser is primarily composed of the shell, tube plate (also known as the header), tube bundle, and top cover (also referred to as the head). Parallel tube bundles are fitted inside the circular shell, with the ends of the tubes fixed to the tube plate. The method of fixing tubes to the tube plate usually involves welding or expansion. The top cover, equipped with import or export tubes, is connected to the shell ends' flanges with screws, forming a fluid distribution chamber between the top cover and the tube plate. It is widely used due to its simple and sturdy structure, ease of manufacturing, broad material range, high processing capacity, and versatility.
During heat exchange, cooling water enters through the connection pipe at the top cover, flows within the pipes, and this path is known as the tube side; harmful vapor flows in the gap between the tube bundle and the shell, and this path is called the shell side; the surface area of the tube bundle is the heat transfer area. In condensation recovery, whether it is the condensation of saturated vapor or the condensation with non-condensable gas, generally speaking, condensation in the shell side of the horizontal condenser is more reasonable, as it is more suitable in terms of heat transfer, pressure drop, and cleaning.

Tubular Condenser Types
(1) Fixed tube sheet heat exchangers: Simple and compact design, capable of withstanding high pressures, cost-effective, easy to clean in the tube side, and easy to block or replace when tubes are damaged.
(2) Floating Head Heat Exchangers: Easy to clean inside and between tubes, without generating thermal stress.
(3) U-tube Heat Exchanger: Featuring a single tube plate, the bundle is composed of multiple U-shaped tubes. Both ends of the tubes are fixed on the same tube plate, allowing for free expansion and contraction. No thermal stress is generated when there is a temperature difference between the shell and the U-tube heat exchanger.
(4) Sliding Tube Sheet Heat Exchangers: Simple structure, low cost, and can add baffles to the tube box as needed to enhance heat transfer.

Features of Tube-in-Tube Condensers
(1) Horizontal shell-side condensing film heat transfer coefficient is several times higher than that of vertical tube internal or external film heat transfer coefficient, and non-condensibles do not accumulate in dead corners, making them easier to discharge.
(2) The cooling water flows through the pipes, making it easier to clean out scale. Water flowing within the pipes can be maintained at a higher velocity, which is beneficial for reducing the rate of scale formation and increasing the heat transfer coefficient of the water film.
(3) Tube-in-tube condensers position the lower tubes at the cooling water inlet, allowing condensate to accumulate at the bottom for temperature reduction. In surface condenser systems, further cooling of the condensate is crucial. High temperatures in the condensation system lead to significant vaporization of organic gases upon contact with air. Typically, the outlet temperature of the condensate should be 60°C or lower. Of course, an additional cooler can be added, but this will increase costs.