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Scale-up factors

The need for a pilot plant is a measure of the degree of uncertainty in developing a process from the research stage to a hiU commercial plant. A modification to a weU-known process may go directiy from basic research work to design of a commercial plant using this approach for a brand new process risks a significant failure. Hence, one or more intermediate size units are usually desirable to demonstrate process feasibiUty as well as to determine safe scale-up factors. [Pg.39]

Process plant design has come a long way from the early 1930s when process designers used the rule-of-thumb that a process faciUty could not be scaled-up more than 10-fold (2). American Oil s Ultracracking unit (Texas City, Texas) for example, was designed from data from a small pilot plant with a scale-up factor of 80,000 (3). [Pg.40]

Scale-up Factors Factors used in thickening will vary, but, typically, a 1.2 to 1.3 multiplier applied to the unit area calculated from laboratory data is sufficient if proper testing procedures have been followed and the samples are representative. [Pg.1681]

There will be many times when the quantity of sample is limited. While it is best to use the 92.9 cm" (0.1 ft") area leaf in order to minimize edge effects and improve accuracy, when the sample volume is limited it is much better to have several data points with a smaller leaf than onl one or two using the larger leaf. Data from leaves as small as 23.2 cm" (0.025 ft") are reasonably accurate and can be used to scale up to commercially sized units. However, it is usually prudent to employ a more conservative scale-up factor. [Pg.1696]

Nominal filter area approximately equal to ac tual area A representative sample Suitable choice of filter medium Operating conditions equal to those used in testing Normal cloth conditioning during testing and operation The scale-up factor on rate specifically does not allow for ... [Pg.1703]

Where there is any doubt about some of the conditions listed above (except for cake discharge and actual area which should be handled separately) a more consei vative scale-up factor should be used. [Pg.1703]

For most apphcations, the actual area of a drum filter will generally be no less than 94 to 97 percent of the nominal area, depending upon the size and number of sections. This variation is generally not accounted for separately and is assumed to be taken care of in the scale-up factor on filtration rate. [Pg.1703]

Overall Scale-Up Factor The final design filtration rate is determined by multiplying the bench-scale filtration rate by each of... [Pg.1703]

Scale-up factors On rate = 0.8 On area = 0.8 On discharge = 0.9. (Scale-up on discharge maybe increased to 0.97 if based on previous experience or to 0.95 if the total filter area is based on the measured effective area of the disk.)... [Pg.1703]

Overall scale-up factor based on the factors presented previously = 0.8 X 0.8x0.9 = 0.58... [Pg.1704]

Type of centrifuge Inside diameter, in Disk diameter, in/niimher of disks Speed, r/min 2, value, units of 10 fF Recommended scale-up factors"... [Pg.1734]

These scale-up factors are relative capacities of centrifuges of the same type hut different sizes when performing at the same level of separation achievement (e.g., same degree of clarification). These factors must not he used to compare the capacities of different types of centrifuges, f Approaches 2.5 at rates helow mL/min. fLong howl configuration. [Pg.1734]

Other scale-up factors are shear, mixing time, Reynolds number, momentum, and the mixing provided by rising bubbles. Shear is maximum at the tip of the impeller and may be estimated from Eq. (24-5), where the subscripts s and I stand for small and large and Di is impeller diameter [R. Steel and W. D. Maxon, Biotechnm. Bioengn, 4, 231 (1962)]. [Pg.2140]

When using dimensional analysis in computing or predicting performance based on tests performed on smaller-scale units, it is not physically possible to keep all parameters constant. The variation of the final results will depend on the scale-up factor and the difference in the fluid medium. It is important in any type of dimensionless study to understand the limit of the parameters and that the geometrical scale-up of similar parameters must remain constant. [Pg.127]

Figure 7-17. Mixing scale-up factors referenced to experienced ratios of power per unit volume. (Source Penny, N. R Chem. Engr., p, 88, March 22, 1971.)... Figure 7-17. Mixing scale-up factors referenced to experienced ratios of power per unit volume. (Source Penny, N. R Chem. Engr., p, 88, March 22, 1971.)...
Figure 5.17 Effect of scale-up factor ( Figure 5.17 Effect of scale-up factor (<i/4ab) ow overall attrition rate for constant (Synowiec etai, 1993)...
There is no constant scale-up factor for each specific mixing system/process [29]. The two independent impeller variables come from speed, diameter, or power, because once the impeller type/style has been selected. [Pg.315]

There has to be a relation between kLa with aeration rate and agitation speed, and scale-up factor has to be determined. To eliminate the effect of viscous forces, the rheology of the media and broth for a large vessel have to be similar to that of a bench-scale vessel. For scale-up based on geometric similarity, the constant values a and b are proposed for the mass-transfer correlation in Table 13.1. [Pg.289]

Let us scale-up a small fermenter with volume (V) of 0.3 m3. The scale-up factor is 200 fold. The large fermenter has a volume (V2) of 60 m3. The working volume is 60% of nominal volume, that is... [Pg.316]

Until about the second World War chemical processes were developed in an evolutionary way by building plants of increasing size and capacity. The capacity of the next plant in the series was determined by a scale-up factor that depended mainly upon experience gained from scale-ups of similar plants. Due to a lack of predictive models for chemical processes and operations, processes had to be scaled up in many small steps. This procedure was very expensive and the results unreliable. Therefore, large safety margins were incorporated in scale-up procedures, which often resulted in a significant unintended overcapacity of the designed plant. [Pg.194]

The project cost of a 1,000 ton/day ammonia plant that was built in 1969 has been obtained, using Equation 9-1 with an m of 0.70 and 0.88 and the CEPI. The results appear in Table 9-5. The effect of the exponential factor is very evident for plants 1 and 2. This effect does not occur for the other plants because their rated capacity was the desired 1,000 tons/day. Exponential factors are only used when capacity extrapolations must be made. This illustrates how a difference of 0.18 in the exponential factor (m) can have a profound effect on the projected cost if the scale-up factor is large. This can be further demonstrated by drawing lines of these two slopes on log-log paper (Fig. 9-1). As the lines get farther away from the base... [Pg.244]

Laboratory studies are very important for providing basic knowledge to scale-up of batch reactions. Modeling a batch system is very important as well. When the batch reaction and system are well understood, a large scale-up factor may be applied while still maintaining safe operations. [Pg.139]

The initial bench-scale experimental investigations into solvent extraction processes are conducted with small apparatus, such as separating funnels. Following the successful completion of these tests, when the best reagent and other conditions for the system have been established, small-scale continuous operations are run, such as in a small mixer-settler unit. The data so obtained are used to determine scale-up factors for pilot plant or plant design and operation (see Chapters 7 and 8). [Pg.281]

Many factors act together to determine the optimum scale of a process. These include the demand for the product, competitors share of the market, any technical limitations on the size of operation and also economies of scale effects. There is an approximate logarithmic relationship between the unit production costs for a product and the volume of production, whereby considerable economies of scale can be achieved. If the costs of a process of one size (C ) is known then the costs of larger or smaller factories (C ) can be approximately obtained from the relationship C = Cx (or n° ), where n is the scale-up ratio, i.e. n=l for a plant that is twice as big. Alternatively, a graph of log capital costs vs. log of plant capacity gives a straight line with a slope equal to the scale-up factor (n). The power term varies from case to case, but is invariably less than one. This scale effect is one reason why unit production costs are inversely proportional to the scale of manufacture. For example, most amino acids are expensive and can only be used in... [Pg.473]

Cartensen JT, Metha Ashol. Scale-up factors in the manufacturing of solution dosage forms. Pharm Technol 1982 6(ll) 64-77. [Pg.87]


See other pages where Scale-up factors is mentioned: [Pg.517]    [Pg.216]    [Pg.1621]    [Pg.1621]    [Pg.1702]    [Pg.1702]    [Pg.1704]    [Pg.1704]    [Pg.1724]    [Pg.1734]    [Pg.1839]    [Pg.1050]    [Pg.305]    [Pg.102]    [Pg.194]    [Pg.159]    [Pg.455]    [Pg.225]    [Pg.66]    [Pg.873]    [Pg.53]    [Pg.60]   
See also in sourсe #XX -- [ Pg.282 ]




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Common Scale-Up Factors

Factorization scale

Factors in equipment scale-up and design

Overall Scale-up Factor

Scale factor

Scale-up

Scale-ups

Scaling factor

Up scaling

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