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Polymer recirculation rate

The polymer recirculation rate has a direct influence on the amount of gas flowing down the downcomer, which results in the need to limit such polymer flow to the minimum allowable by the thermal balance of the downcomer. [Pg.570]

Figure 3.46 Flux vs recirculation rate in linear thin channels (styrene butadiene polymer latex). Figure 3.46 Flux vs recirculation rate in linear thin channels (styrene butadiene polymer latex).
If the gel layer is not the limiting resistance to flow, the layer will continue to grow until the channel is completely full of 75% solid material-resulting in a drop in recirculation rate with time. Thin channel tubes and spiral flow modules running continuously at constant latex feed concentration and pressure drop for periods approaching one year have shown no decreases in recirculation rate or accumulation of polymer latex in the channels. [Pg.186]

In loop reactors, the high recirculation rate leads to high turbulence and high heat-transfer coeflRcients. Additionally, the high heat-transfer area available in these reactors permits efficient removal of heat of polymerization and therefore high polymer yields. [Pg.423]

Two other compounds have been examined for therapeutic action in animal (rat) models of chlordecone poisoning. Sporopollenin, a carotenoid polymer derived from the cell walls of the alga Chlorella prothecoides, was reported to bind to chlordecone (Pore 1984). In animal studies using rats, sporopollenin decreased the half life of chlordecone from 40 days to 19 days. The excretion rate in control animals fed a-cellulose, in the same bulk amount as sporopollenin, did not change. Prevention of enterohepatic recirculation of chlordecone was also evaluated with liquid paraffin. [Pg.149]

Dose rates for polyacrylates vary considerably, depending on particular applications and whether they are incorporated in formulations with other polymers. However, for general purposes, the dose rate will tend to be from 1.25 to 5.0 ppm as actives in the recirculating cooling water. For particular applications (such as iron stabilization), there may need to be 5.0 to 10.0 ppm actives present. [Pg.156]

This term varies significantly with the nature of the fuel. Liquid fuels are characterized by the presence of recirculation currents induced by buoyancy. These currents homogenize the temperature distributions, reducing in-depth conduction. Nevertheless, convective motion transfers heat to the interior of the pool leading to an additional term of in-depth convection. Convective heat transfer in polymer melts has a similar behavior and could potentially have an important effect on burning rates nevertheless, the impact of polymer melt rheology on the flammability of materials is still a matter of great controversy. [Pg.69]

In a previous work (5), it was shown that the effect of mixing on reactor performances is very important. In particular, it was discussed that a) the mixing inside the reactor can be characterized by a recirculating flow rate caused by the impeller in the reaction zone, and that b) an imperfectly mixed reactor requires a higher initiator consumption per polymer produced than a perfectly mixed one operating at the same conditions. [Pg.592]

Fluidization in the reactor s polymer bed is maintained by adequate recirculation of reacting gas. The reaction heat is removed from the recycle gas by a cooler, while the cooled gas is recycled back to the bottom of the gas-phase reactor for fluidization. This gas-phase reactor maintains a high degree of turbulence and enhances monomer diffusion and reaction rates, and ensures an efficient particle heat removal. [Pg.572]


See other pages where Polymer recirculation rate is mentioned: [Pg.737]    [Pg.737]    [Pg.571]    [Pg.573]    [Pg.320]    [Pg.303]    [Pg.7]    [Pg.288]    [Pg.190]    [Pg.521]    [Pg.1681]    [Pg.283]    [Pg.406]    [Pg.92]    [Pg.294]    [Pg.567]    [Pg.39]    [Pg.266]    [Pg.1502]    [Pg.521]    [Pg.232]    [Pg.567]    [Pg.600]    [Pg.567]    [Pg.567]    [Pg.32]    [Pg.42]    [Pg.493]    [Pg.494]    [Pg.41]    [Pg.52]    [Pg.108]    [Pg.21]    [Pg.521]    [Pg.1685]    [Pg.406]    [Pg.266]    [Pg.107]    [Pg.188]    [Pg.354]    [Pg.132]    [Pg.721]   
See also in sourсe #XX -- [ Pg.571 ]




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Recirculation rates

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