Polymer film heat exchanger

Polymer film heat exchanger Chemicals and petrochemicals Prime movers Aerospace... 

Zaheed, L. and Jachuck, R.J.J. (2004). Review of polymer compact heat exchangers, with special emphasis on polymer film unit. Applied Thermal Engineering, Vol. 24, pp. 2323-2358. 

The polymer can easily be recovered by simple vacuum filtration or centrifugation of the polymer slurry. This can be followed by direct conversion of the filter cake to dope by slurrying the filter cake in chilled solvent and then passing the slurry through a heat exchanger to form the spinning solution and a thin-film evaporator to remove residual monomer. 

BURNS, J. R. and JACHUCK, R. J. J. App. Thermal Eng. 21 (2001) 495-510. Condensation studies using cross-corrugated polymer film compact heat exchanger. 

Nonmetallic conductors and corrosion products. Carbon brick in vessels is strongly cathodic to the common structural alloys. Impervious graphite, especially in heat-exchangers, is cathodic to structural steel. Carbon-filled polymers can act as active cathodes. Some oxides or sulfates are conductors, such as mill scale (magnetite Fe304), iron sulfides on steel, lead sulfate on lead can act as effective cathodes with an important area to that of the anodes. Very frequently, the pores of the conductive film are the preferable anodic sites that leads to localized corrosion (pitting).5... 

Impregnation and polymerization of vinyl monomers in polymeric films. Vinyl monomers swell some kinds of polymer films styrene and divinylbenzenes swell poly(vinyl chloride) films substantially. After a polymer film such as poly(vinyl chloride) or polyethylene has been swollen in a vinyl monomer mixture containing a radical initiator, the film is covered with another film that does not swell with the vinyl monomers, e.g. cellulose film, poly(vinyl alcohol) film, and heated to polymerize the monomers in the film. Ion exchange groups are introduced into the resulting precursor membrane, for example by sulfonation, chloromethylation... 

Figure 3. BNL absorber/heat exchanger incorporating a polymer film and foil laminate.

Polymer film back surface (oriented PET) Laminate Absorber/heat exchanger (FEP) Optical selective coating (treated nickel foil)... 

The major key to low cost Is a solar collector design which has low material Intensity and Is capable of being produced at very high speed to reduce labor Intensity. The low material Intensity results from the use of polymer films and film laminates. The development of an efficient non-pressurlzed thin film absorb-er/heat exchanger also contributes to minimum material requirements. The use of a simple roll-formed sheet metal frame with a cost one third that of a conventional extruded frame further reduces the cost and can be produced as one piece to be bent around the Insulating substrate. The weather seals are Integrated Into the fllm/adheslve attachment for simplicity, reliability and very low additional material requirements. 

The necking phenomenon observed upon stretching a polymer film at a constant temperature is a well-known consequence of a negative feedback loop driven by the interplay between the increase in temperature associated with the sample deformation and its glassification caused by the heat exchange with the environment (55). Oscillatory behavior and period-doubling in the stress resulting from a constant strain rate have been experimentally observed. 

Figure 4.10 Polymer film cross-flow heat exchanger plates.

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