Twisted Elliptical Tube Heat Exchanger as a New High-efficiency Heat Exchanger with Helical Cross Section, It Has Characteristics of High Heat Transfer Coefficient of Baffle Plate Heat Exchanger and Reduced Barrier Rod Heat Exchanger Pressure. The idea of a twisted elliptical tube heat exchanger was applied to the actual heat exchanger manufacturing, mainly by Alards of Sweden and later Brown Fintube of the United States. Later, Brown Fintube of the US improved the production of twisted elliptical tube heat exchangers. The company’s researchers, Blazo Ljubici, also studied heat transfer and flow resistance characteristics. As a new type of heat exchange equipment, the twisted elliptical tube heat exchanger has gradually demonstrated its advantages in the chemical, petroleum and steel industries. The application data from the petrochemical industry shows that the heat exchanger can save nearly 25% in cost compared to ordinary baffle heat exchangers.
Twisted Elliptical Tube Heat Exchanger Structure
The twisted elliptical tube heat exchanger is a twisted oval tube with a certain lead rolled by a round tube as a heat exchange element. The elliptical cross-section is a spiral flow path along the tube length. This spiral elliptical flow path enables the tube flow to produce a complex flow that is characterized by rotation to obtain strong rotational disturbances. The shell side of the heat exchanger is in contact with the tube at the point where the long axis of the adjacent tube contacts, eliminating baffle baffles, making the arrangement of twisted elliptical tubes compact in the heat exchanger shell, reducing the size and quality of the heat exchanger, and at the same time It can also well overcome the vibration of heat exchange tubes. The shell-side flow is affected by the centrifugal force and periodically changes the flow velocity and the flow direction, which enhances the longitudinal mixing of the fluid. At the same time, the fluid passes through the contact points of the spirals of the adjacent pipes to form a wake that is separated from the pipe wall, increasing the turbulence of the fluid itself and destroying the heat transfer boundary layer of the fluid on the pipe wall, thereby enhancing the heat transfer.
Twisted Elliptical Tube Heat Exchanger Features
The traditional shell-and-tube heat exchanger adopts a smooth tube as a heat transfer element, and the shell process adopts a baffle structure, which has the advantages of convenient installation and reliable operation. The twisted elliptical tube heat exchanger has the following characteristics in comparison with the baffle heat exchanger, in addition to the enhanced heat transfer of the secondary flow in the tube:
(1) Shell-side fluid is longitudinal flow. This structure effectively reduces the pressure drop caused by the constant change of the flow direction of the baffled heat exchanger shell side fluid in the flow process, and avoids the dead zone and fouling of the connecting part of the baffle plate and the shell. Increasing the area of the effective heat exchanger, while the characteristics of the longitudinal flow can also reduce the heat transfer tube vibration caused by lateral flushing heat transfer.
(2) The shell side adopts a multi-point self-supporting structure of the tube bundle. Due to the existence of self-supporting, the shell-side flow channel has the characteristics of integration and gridding. The fluid in the shell-side channel periodically impacts the heat exchange tube wall surface due to the effect of the grid point, and strengthens the longitudinal mixing of the fluid and improves the heat exchanger shell process and heat transfer effect.