Scale-up procedures

Scale-up and performance of a 1.47-m Scheibel column have been reported (98,154,155), as have detailed description and design criteria for the Scheibel column (156) and scale-up procedures (157). The same stage efficiency can be maintained on scale-up, and total throughput can be increased by three and one-half times at the expense of higher HETS. As of this writing, Scheibel columns up to 2.75 m in diameter are in service. 

Horizontal Belt Filter Since the total cycle of a horizontal belt filter occurs on a single, long horizontal surface, there is no restriction with respect to the relative portions of the cycle. Otherwise, scale-up procedures are similar. 

For scale-up procedure, refer to Figure 5-31, w hich outlines the steps involved in selecting commercial or industrial mechanical agitation equipment when based on test data. 

A Direct Experimental Approach to Sizing Emergency Relief Systems—Prototype and Data with Scale-up Procedure, DIERS/.MChE, 1986, 36 pages. 

Hufton et al. [120] tested gauze u Je packing for large conunercial units, which resulted in a scale-up procedure that is too involved to reproduce here. 

SCALE-UP PROCEDURE FROM LABORATORY SCALE TO PLANT SCALE... 

Wypych. P. W. and Arnold, P. C. Powder Technol. 50 (1987) 281. On improving scale-up procedures for pneumatic conveying design,... 

As illustrated above there exist a large variety of techniques for preparing liposomes. From a pharmaceutical point of view, optimum liposome preparation techniques would avoid the use of organic solvent and detergents (which are difficult to remove), would exhibit a high trapping efficiency, would yield well-defined vesicles which can be produced in a reproducible way, and would be rapid and amenable to scale-up procedures (see Sec. VIII). 

Ultrasound can thus be used to enhance kinetics, flow, and mass and heat transfer. The overall results are that organic synthetic reactions show increased rate (sometimes even from hours to minutes, up to 25 times faster), and/or increased yield (tens of percentages, sometimes even starting from 0% yield in nonsonicated conditions). In multiphase systems, gas-liquid and solid-liquid mass transfer has been observed to increase by 5- and 20-fold, respectively [35]. Membrane fluxes have been enhanced by up to a factor of 8 [56]. Despite these results, use of acoustics, and ultrasound in particular, in chemical industry is mainly limited to the fields of cleaning and decontamination [55]. One of the main barriers to industrial application of sonochemical processes is control and scale-up of ultrasound concepts into operable processes. Therefore, a better understanding is required of the relation between a cavitation coUapse and chemical reactivity, as weU as a better understanding and reproducibility of the influence of various design and operational parameters on the cavitation process. Also, rehable mathematical models and scale-up procedures need to be developed [35, 54, 55]. 

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. 

Some typical fluid bed capacities used in the pharmaceutical industry are given in Table 2. From this information, it can be seen that for beds up to 450 mm (18") in diameter, one draft tube is typically used. The diameter of the draft tube is nominally one-half the bed diameter. For larger beds, the use of multiple draft tubes, 225 mm in diameter, is common. Also shown in Table 2 are the heights ofthe draft tubes used in each bed. Since the solids in the bed are filled close to the top of the draft tube, the capacity of the equipment is determined by the diameter of the bed, the height of the draft tube, and the density of the bed solids. An example illustrating the scale-up procedure is given below ... 

An example of the application of a unified model to the design of a three-phase, fluidized bed bioreactor is the scale down, scale up procedure. A model of the full scale reactor is developed, then is used to design... 

The above test-design and scale-up procedures have been applied to numerous long-distance systems (e.g., fly ash, pulverized coal) and have been found to provide good accuracy and reliability. Some examples of these results have been presented by Pan and Wypych (1992a) and Pan and Wypych (1994). The interested reader is referred to these papers for further details. The above procedures also have been used successfully to... 

Pan, R., and Wypych, P. W., Scale-Up Procedures for Pneumatic Conveying Design, Powder Handling Processing, 4(2) 167—172 (1992a)... 

Decrease of specific rates during scale-up procedure. 

The other change that needed to be made in the synthesis of RSR 13 for in vivo administration was the method of purification. RSR 13 is used in vivo as the sodium salt. I prepared the first batch for in vivo toxicology by triturating RSR 13 sodium salt with acetone to remove any vestiges of water. However, the first industrial scale-up procedure called for crystallization of the salt from ethanol-water. The ethanol-water crystals were not as soluble as the acetone triturated method and could not be formulated at a reasonable volume. We performed the crystal structure determination of the ethanol-water crystals and found that it was a heptahydrate (Figure 17.5) [50]. The problem for large-scale production of RS R13 was solved eventually by the industrial producers of RSR 13. 

Scale-up of spin-filters has been often studied in the recent years, and simple scale-up procedures have been proposed by Yabannavar et al. [81] and Deo et al. [13]. Yabannavar et al. [81] suggested a procedure based on keeping the ratio of permeation drag to lift force constant for the different production scales, in... 

Rapid production scale-up procedures. If these procedures are established before they are needed, they can be implemented immediately in an attack. Although investigation into scale-up of all stages of production should occur, the scale-up of separation and purification is a specific challenge. 

A new method for the preparation of soy sauce has been developed. The new scaled-up method divides the moromi process into two processes autolysis and fermentation. Because of the utilization of high temperatures, the new process permits the production of a NaCl free autolyzate from koji. Division of the fermentation process into two separated processes permit better control of lactic acid fermentation and alcohol fermentation processed which used to require great skill. The new scale-up procedure for soy sauce production yields a product in half the time required by the traditional (conventional) method and still produces a soy sauce with high levels of the desirable Bavor component, glutamic acid. Utilization of this protocol by the soy sauce producing industry should have significant economic impact to bo producers and consumers. 

Bohme G, Stenger M. Consistent scale-up procedure for power consumption in agitated non-Newtonian fluids. Chem Eng Technol 1988 11 199-205. 

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