Vessel sizes

STAC, with their current new design (pool reactor), feel the only size limitation will be vessel size. Unless both the vessel fabricator and the intended plant site are "on water", a 4-m-diameter is the maximum that can be transported. 

Variables It is possible to identify a large number of variables that influence the design and performance of a chemical reactor with heat transfer, from the vessel size and type catalyst distribution among the beds catalyst type, size, and porosity to the geometry of the heat-transfer surface, such as tube diameter, length, pitch, and so on. Experience has shown, however, that the reactor temperature, and often also the pressure, are the primary variables feed compositions and velocities are of secondary importance and the geometric characteristics of the catalyst and heat-exchange provisions are tertiary factors. Tertiary factors are usually set by standard plant practice. Many of the major optimization studies cited by Westerterp et al. (1984), for instance, are devoted to reactor temperature as a means of optimization. 

The distinguishing feature of this dryer is the bottom-screw drive, as opposed to a top-drive unit, thus ehminating any mechanical drive components inside the vessel. The bottom-driven screw rotates about its own axis (speeds up to 100 rpm) and around the interior of the vessel (speeds up to 0.4 rpm). The screw is cantilevered in the vessel and requires no additional support (even in vessel sizes up to 20 m operating volume). The dryer is available in a variety of materials of construction, including SS 304 and 316, as well as Hastelloy. 

PFRs, under isothermal, adiabatic, or heat transfer conditions in one or two phases. Outputs can provide profiles of composition, pressure, and temperature as well as vessel size. 

Aerobic Fermentation The classic example of large-scale aerobic fermentation is the production of penicillin by the growth of a specific mold. Commercial vessel sizes are 40,000 to 200,000 L (1,400 to 7,000 ft ). The operation is semibatch in that the lactose or glucose nutrient and air are charged at controlled rates to a precharged batch of liquid nutrients and cell mass. Reaction time is 5 to 6 days. 

X = Abscissa of Smith-Dresser-Ohlswager correlation, or abscissa of Norton Generalized Pressure Drop Correlation, or Fluor vessel sizing separation factor or evaporator temperature, °F... 

The carbons are broadly comparable in terms of their maximum concentration and implied energy efficiency but the two monolithic forms offer the advantage of smaller pressure vessel sizes and improved heat transfer. 

One of the differences between polishing and cake filtration is the space between the plates. For polishing applications the clearances are about 20 mm as opposed to cake filtration applications where, depending on the percentage of solids and cake build-up properties, clearances may reach 100 mm. Hence, polishing filters accommodate more plates than cake filters so for the same vessel size more effective area is available with polishers. 

This shows that as the vessel size increases, the volume increases at a faster rate than the surface area. Thus, care must be taken before scale-up is implemented as even a small increase in volume can result in insufficient cooling and subsequent loss of control. 

The total number of fragments is a function of vessel size and periiaps other parameters. Holden (1985) gives a correlation based on 7 incidents as equation 9.1-35. where F is the number of fragments and V is the vessel volume in m for the range 700 to 2,500 m. ... 

In the analysis of Synowiee etal. (1993), while the turbulent attrition rate is predieted to be eonstant with inereasing seale of operation at eonstant power input, the impaet attrition rate is predieted to deeline with the square of vessel size. In eombination... 

The assumption of perfeet mixing applied in the bateh and eontinuous MSMPR erystallizer models does not always apply, however, espeeially as vessel size inereases. Methods for aeeounting for imperfeet mixing and seale-up are eonsidered in the next ehapter. 

The SFTR reaetor uses two immiseible fluid phases (gas or liquid) to ereate individual miero volumes of previously well-mixed reaetants. A statie mixer is plaeed upstream, whieh ensures effieient and reprodueible mixing of the reaetants before they enter the reaetor. The reaetor is believed to be potentially suitable for the foreed preeipitation of erystals where the mixing step is of major importanee in determining their ehemieal and physieal eharaeteristies. Instead of sealing up by inereasing vessel size, the SFTR is to be sealed out by replieation of similarly sized eonfigurations, as produetion demands. 

Both operating conditions (viz. precipitant dosage rate) and mixing conditions (viz. precipitant dilution and vessel size) affect the crystai size distribution... 

In selecting acceptable combinations, the bed height should be at least 10 ft for H2S removal and 20 ft for mercaptan removal. This height will produce sufficient pressure drop to assure proper flow distribution over the entire cross-section. Thus, the correct vessel size will be one that has a bed height of at least 10 ft (20 ft if mercaptans must be removed) and a vessel diameter between df in and... 

Assumes vessel size fixed prior to mesh inculry... 

Capacity of the vacuum pump at the working vacuum Example Vessel size = 200 ft ... 

Application Vessel metal Temperature range (°C) Vessel type and purpose Vessel size range t (m) Number of systems Type of controller Po wer supply size range (kW) Date of first installation... 

The factors chosen were variations in vessel size, the effect of non-aseptic operation and medium recycle, and variations in recovery and drying procedures. 

A. Available Design Methods for Vent Sizing. Several methods are available to size the vent with a wide range of sophistication. The FIA chart, Fig. 1 prepared by the Factory Insurance Association in the mid 1960 s is a simple chart summarizing a wealth of experience. Reactions are classed by the degree of exothermic reaction. With vessel size and a judgment of reaction type a vent size range can be selected. 

Table 7.4-17 Vessel sizes, L (rounded to full litres)...

Bioremediation also has its limitations. Some chemicals are not amenable to biodegradation, for instance, heavy metals, radionuclides, and some chlorinated compounds. In some cases, the microbial metabolism of the contaminants may produce toxic metabolites. Bioremediation is a scientifically intensive procedure that must be tailored to site-specific conditions, and usually requires treatability studies to be conducted on a small scale before the actual cleanup of a site.13 The treatability procedure is important, as it establishes the extent of degradation and evaluates the potential use of a selected microorganism for bioremediation. A precise estimate on vessel size or area involved, speed of reaction, and economics can therefore be determined at the laboratory stage. 

MacCary, R.R. How to Select Pressure-Vessel Size, Chemical Engineering, Oct. 17, 1960, p. 

The presence of metastable decompression paths having transient pressures temporarily much smaller than the temperature equilibrium values could not be absolutely confirmed or refuted. If present, they persist for only 1 msec and do not seriously affect the decompression time of the driver tube, and the duration is independent of vessel size. 

---