Replacement fin

Actually, retrofitting a tube bundle with low fin tubes often reduces heat-transfer capacity. This happens when the controlling resistance to heat transfer is shell-side fouling. The fouling deposits get trapped between the tiny fins. This acts as an insulator between the shell-side fluid and the surface of the tubes. In severe shell-side fouling services, I have replaced fin tubes with bare tubes, and doubled the heat-transfer duty on the exchanger. 

Figure 5.2 Schematic of how the defect trapping technique used in the replacement fin approach traps dislocation defects against the sidewalls of trenches with high aspect ratios. Situation shown post-CMP and recess etch.

CMP process development on Ge/SiCe replacement fin wafers and process results... 

Studies from several institutions have shown that it is possible to set up a working III—V CMP process using proprietary slurries or homemade model slurries (Matovu et al., 2014 Hill et al., 2013 Ong et al., 2013 Baneijee, 2014). Adjustments to the slurry composition and appropriate pad choice allow the development of IE-V poUsh-ing processes that achieve low IE—V roughness post-CMP and/or can remove the 111—V overburden in a replacement fin design approach. A stable and reproducible III—V CMP process is needed to ensure the formation of El—V channel layers of... 

Waldron, N., et al., 2014a. An InGaAs/InP Quantum Well FinFet Using the Replacement Fin Process Integrated in an RMG Flow on 300 mm Si Substrates. 2014 Symposium on VLSI Technology Digest of Technical Papers, Honolulu, HI, USA. 

When using finned tubes, the coefficients for the outside of the tube in equation 12.2 are replaced by a term involving fin area and effectiveness ... 

Tubes with low transverse fins, about 1 mm high, can be used with advantage as replacements for plain tubes in many applications. The fins are formed by rolling, and the tube outside diameters are the same as those for standard plain tubes. Details are given in the manufacturer s data books, Wolverine (1984) and an electronic version of their design manual, www.wlv.com (2001) see also Webber (1960). 

Early bubbling FBC units were designed to burn coal, and the heat released was removed by heat transfer to in-bed tubes and/or to the water-wall tubes used to enclose the furnace. These surfaces experienced high rates of metal loss through the combined effects of erosion and abrasion. Protective measures such as plasma-sprayed coatings and metal fins to disrupt the solids flow pattern were used. These were effective for only short periods before requiring replacement, and so maintenance requirements were high. 

All bombs, except the very largest, are packed in wooden boxes or crates. The fin assemblies for the larger bombs are also crated when packed separately from the bombs. Some bombs are packed with fuzes inserted but with primer-detonators removed. However, rhe fuzes are usually removed and packed in sealed moisture-proof containers. In the latter case the fuze wells in the bombs must be closed with plugs. Some fuzes are packed in the same containers with the bombs, others separately. Bombs and components are stored as shipped. Complete rounds should not be assembled in advance of requirements and assembled rounds should be carried with sealing wires and safety in place at all times until installation in the plane. The arming wire should remain in place until the bomb is released, or until the safety pins and sealing wire are replaced and secured... 

The hermitean character of the F operator allows the replacement of F, 4 by the complex conjugate of F 4 r This matrix element can be related to Fin if it is assumed that F either commutes or anticommutes with time reversal. 

A good approach to this kind of problem is to begin by calculating the possible hydrocarbon formulas. First divide the molecular weight by 12 to fin d the maximutn number of carbons possible. Each carbon is equal in mass to 12 hydrogens, so the next step is to replace I C by 12 H, giving anotlior possible formula. 

Figure 8 shows the energy savings if flue gas is cooled down to a lower outlet temperature. In general, additional heat transfer surface has to be installed to transfer this additional flue-gas heat. However, in some cases it might be sufficient to replace bare tubes by finned or... 

Drill or punch out the eight small fin rivets.Move fin assembly forward one inch and mark/drill new front holes in the tail tube. Remove the fin assembly and use tin snips to cut the fins along line F.Spread and space each fin as shown.Carefully trim each fin to the correct dimensions and reinstall on tail tube. Use small screws instead of rivets, as they will be removed and replaced later on. (seeppwa)... 

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