Heat exchanger conduits

The equation for forced-convective heat transfer in conduits can be used for plate heat exchangers equation 12.10. 

The modular backbone introduced here allows both commercial and demonstration-type micro structured devices to be coupled in all three dimensions in a flexible and easy manner. Micro structured heat exchangers, reactors and mixers of different manufacturers are surface mounted on this backbone. Owing to the standardized interfaces, devices can easily be exchanged, for example, to evaluate different types of mixers. The backbone itself consists of elements which can be combined individually and flexibly in all directions, according to the demands of the plant to be built. The backbone provides the flow paths for fluids and electrical conduits for power supply and signal transmission of sensors and actuators. 

Any conduit system that has low dispersion will also provide very fast heat transfer rates. Serpentine tubing has been also used in commercial column ovens to heat the mobile phase rapidly to the column oven temperature before it enters the column. The serpentine tubing allows effective heat exchange with a minimum of heat exchanger volume to distort the concentration profile of the solvent gradient. 

Because motionless mixers continuously interchange fluid between the walls and the center of the conduit, they also provide good heat transfer, especially with the twisted-element style of mixers. Sometimes, high-viscosity heat exchange is best accomplished with a static mixer. 

To reduce the space required for this recovery, to improve the density and control the purity, and to reduce the amount of manual labor required, it has been proposed to accomplish recovery by use of a sequence of steps (1) cool the vaporous mixture by passage through a water-cooled tubular cooler condenser, (2) remove the bulk of the condensed material by means of a scraper-screw conveyer in the cold end of this cooler, and (3) recover dust from the cold gases by means of a bag filter. Fractional condensation of phthalic anhydride from gas-vapor mixtures containing maleic anhydride may be accomplished by maintaining the mixture in the temperature range of 80-90 C to 132 C by indirect heat exchange with a fluid confined in tubular conduits. ... 

The reactive solution flows downwardly from the chamber 24 through heat exchanger tubes 27 disposed within a 35 plurality of tanks 28 spaced around the reaction tank 10 as best seen in FIG. 2, a heat exchange fluid being circulated tiirough each tank 28 by inlet and outlet conduits 30 and 31. Ihe reactive solution flows from the lower... 

Wherever particles are involved, the problem of fouling, or deposition on surfaces arises. In the case of heat exchangers for combustion gases, thermal transfer efficiency may be drastically reduced by the deposition of the relatively highly insulating soot and flyash particles. In other contexts sulfuric acid and other corrosive vapor droplets diffuse or impact upon conduit surfaces thereby shortening their useful lifetime [1.22,25]. In all of these cases, numerous questions of kinetic theory arise including all the phoretic forces. In addition, particle interaction forces are ultimately responsible for delivery to the surface in question. 

Miniature heat-removal devices Micro-heat exchangers MicroChannel heat sinks (MCHS) Row of coolants in micro-conduits Nanofluid flow in microcharmels... 

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