Productivity classification

More elongated devices are used for slurry thickening whilst those of more squat aspect ratio devices are suitable for product classification by size, as in fines-destruction circuits. The pressure drop in a hydrocyclone varies with the feed rate raised to a power between 2 and 3.3. The cut size is a weak function of pressure drop, varying with for dilute feeds. Large pressure drops are... 

A key product classification scheme in the chemical industry is the differentiation of specialty and commodity products. Kline (1976) provides a segmentation of the chemical industry into commodities, specialties and fine chemicals shown in fig. 28. 

The development of chemical products has been led by the industry. Not surprisingly, the language that is used has served to the necessities of the company and the market. That is why product classifications have been ambiguous and changing through time [26], For example, chemical products had been classified based on the prices and uses. 

An alternative chemical product classification in terms of volume produced, cost, function of product and processing needs has been discussed in chapter 1. 

The Finnish ThermoWood Association was formed in December 2000. The main roles of the association are quality control of the material, product classification and R D activities. Although ThermoWood production is primarily located in Finland, there is limited production in Austria and Estonia a small-scale production facility was also due to start producing in Canada at the end of 2004. 

Product classification, the selective removal of the large crystals as the product, is generally used to reduce the coefficient of variation (CV) of the crystals produced. 

Product classification is generally realised by product discharge through an elutrlation leg which also serves as a washing step to remove contaminated mother liquor. The stable operation of such an elutrlation leg is difficult and the separation efficiency is unsatisfactory. Previous results ) show that values of both the average size and the coefficient of variation in the product stream delivered from the elutrlation leg differed only slightly from those in the circulation mains in a forced circulation pilot plant crystalllser, as illustrated in Table 1. 

This paper presents the grade-efficiency curves of a 75 n flat bottom cyclone (RWB 1613) provided by the Amberger Kaolin Werke (AKW). It is tested for the ammonium sulfate-water system for both fines removal and product classification. Its results will be compared with the results for fines removal obtained when using an... 

The shape of this classification function is identical to the shape of the grade efficiency curve for product classification but the ordinate values are changed. 

A typical grade efficiency curve for the product classification step is given in Figure 4. A value of nearly 100 percent is attained at large sizes, whereas normally a value equal to or larger than the so-called dead flux is attained at small sizes. This is caused by the diluted discharge of the coarse fraction. It represents the minimum amount of residual fines in the product after one separation stage. 

Figure A typical grade efficiency curve for the product classification step.

Product classification. In product classification promising results have been obtained. The differentiation between underflow and feedflow is considerable, especially if the performance of an elutriation leg is considered. Furthermore, an additional degree of... 

Figure 7. Three grade efficiency curves for the product classification step at the flow rates indicated, while using an apex diameter of 10 mm.

Figure 8. Two grade e Bden(y curves for product classification at the apex diameters shown at a flow rate of 1.4 L/s.

In this paper, three methods to transform the population balance into a set of ordinary differential equations will be discussed. Two of these methods were reported earlier in the crystallizer literature. However, these methods have limitations in their applicabilty to crystallizers with fines removal, product classification and size-dependent crystal growth, limitations in the choice of the elements of the process output vector y, t) that is used by the controller or result in high orders of the state space model which causes severe problems in the control system design. Therefore another approach is suggested. This approach is demonstrated and compared with the other methods in an example. 

The discussion of the transformation methods will be based on the population balance for a crystallizer with fines removal and product classification ... 

The method of lines can handle size-dependent growth rates, fines removal and product classification and is not restricted in the choice of the elements of the output vector y (t). The population densities at the grid points are system states, thus moments, L, CV, population densities at the grid points and the number or mass of crystals in a size range can be elements of y (t). 

Salt, sodium chloride classification compound. Stainless steel, mix of iron and carbon classification mixture. Tap water, dihydrogen oxide plus impurities classification mixture. Sugar, chemical name sucrose classification compound. Vanilla extract, natural product classification mixture. Butter, natural product classification mixture. Maple syrup, natural product classification mixture. Aluminum, metal classification in pure form—element (sold commercially as a mixture of mostly aluminum with trace metals, such as magnesium). Ice, dihydrogen oxide classification in pure form—compound when made from impure tap water—mixture. Milk, natural product classification mixture. Cherry-flavored cough drops, pharmaceutical classification mixture. 

Fig. 1. Grinding mill with product classification and recycled oversize fraction.

The investigator is generally not permitted to include any observations on the FDA-483 relating to labels, promotional materials, product classifications (new drug application [NDA], premarket application [PMA], etc.), or registration requirements. It is not inappropriate to ask why such observations are included on an FDA-483. It could be an error that could result in either removal of the observation or clarification that headquarters has approved its inclusion. 

In the section of the figure reporting post-experience outcomes, varied levels of the range of benefits and psychological states are portrayed. These outcomes include appreciation, achievement, knowledge, skills, social capital, rejuvenation, satiation and even boredom. These three phases of the experience lead to an array of product classifications of tourists. Although the labels are flexible and synonyms may be equally appropriate for some of the terms, the system identifies specialists, the serious and the involved, the determined, generalists, accidental and incidental visitors, dabblers and amateurs, and the disinterested. 

Two examples drawn from different areas of tourist product classifications will illustrate how the conceptual framework illustrated above can heighten the appreciation of existing schemes and build new cross-situational comparisons. 

Tourist demographics and product classifications How observable characteristics account for tourist behaviour, understudied groups of tourists, tourists with focused interests, naming of tourist groups Phase and stage models Cultural differences, classifications Muted voices, gender analysis Specialisation Experience outcomes... 

Given the above disclaimers, Mr. Toscano provided the following The Chemical and Allied Products classification (SIC Code 28) experienced 38 deaths out of a reported 1,289,000 employees (in 1995). This is a relative risk of 0.6, lower than relative risk of the average job (1.0). The 1995 statistics for the Petroleum Refining classification (SIC Code 291) include 13 fatalities out of a listed 151,000 employees. The relative risk is 1.8. 

Related Calculations. Use this procedure to calculate the crystal size distribution from both class I and class II MSMPR crystallizers. This procedure cannot be used to calculate growth rates and nucleation with crystallizers having either lines destruction or product classification. 

A continuous crystallization process ultimately reaches a steady state, in which the rates of nucleation and growth are constant with time. For a given set of operating conditions, crystal size distribution depends considerably upon the degree to which product classification is practiced. Figures 23 and 24 illustrate schematically the possible extremes between... 

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