General Design Recommendations

The bubble cap has been studied extensively and several design recommendations have been presented over the years. The most complete and generally applicable is that of Bolles [5]. It should be stressed that proper mechanical interpretation of process requirements is essential in design for efficient and economic operation. There is not just one result, but a multiplicity of results, each unique to a particular set of conditions, and some more economical than others. Yet at the same time, many of the mechanical design and fabrication features can be identical for these various designs. 

For steam applications, it is generally neither recommended nor usual to use manifolds or headers, but they can be utilised if proper consideration is given to all aspects of the design and installation, and proper draining is provided via, for instance, automatic steam traps. On the other hand, considering current environmental or safety requirements, a lot of process vapours are manifolded into flare headers before being flared off or otherwise treated and disposed of. 

Table 1.2.3 Examples of recommended core and supplemental water quality indicators for general designated use categories (USEPA, 2003)...

D models also can be created with a 3D layout tool, but this is generally not recommended, because designs created outside the context of fabrication processes may not be capable of being fabricated. 

Portions of this Order recommend industry codes and ANSI standards and the applicable portions of 10 CFR Part 50 including the General Design Criteria in 10 CFR Part 50 Appendix A. 

To improve this situation fundamental research is necessary in order to find general design procedures and limits of operation for the process which are independent of the particular column type. This can only be achieved through cooperation between researchers in industry and universities. The European Federation of Chemical Engineers established a Working Party in Extraction for this purpose which recommended liquid systems for testing extraction columns so that the results would be comparable. 

G-8.1 Standard for Nitrous Oxide Systems at Consumer Sites. Covers the general design principles recommended for the installation of nitrous oxide... 

G-8.1 Standard for Nitrous Oxide Systems at Consumer Sites. Covers the general design principles recommended for the installation of nitrous oxide central supply systems—either cylinders connected to a common manifold or systems fed by bulk liquid containers—at medical or industrial consumer sites, with special reference to protection of the system, patients, personnel, and property from fire originating from sources apart from the system itself. (12 pages)... 

In general, the recommendation for adiabatic trickle bed reactors is to avoid internals that obstruct flow and to try to prevent localized partial plugging of the bed through good flow distribution. For reactions that require heat transfer radially through a wall such as in tubular reactors, it is recommended that the pilot plant reactor be run at conditions similar to the commercial reactor. Tests at the low mass velocities typical for pilot plants may be too conservative to get an economic design. 

Published information for industrial scale supercritical extractions is scarce. The same general design considerations will apply as in the subcritical case, through mass transfer rates and equilibrium loadings can be higher. Capital costs are not so easily estimated since the pressures involved fall outside the cost correlations for some of the units. (Use of manufacturer s quotations is recommended, even in the early stages of costing.)... 

If data on minimum conveying air velocities is to be used in the design process, such as that shown in Figure 4.41, it would generally be recommended that a 20% margin be allowed for the value of conveying line inlet air velocity to be employed ... 

General design, specification and application procedures for sealant joints on Exterior Insulation and Finish Systems are discussed with specific recommendations for avoiding sealant joint failure due to finish coat delamination. 

---