Process quantity

In the following table the important process steps (Proc. no.), the process description (Process quantity) (measure), the related target data (Target data) and their tolerances (tolerances) are listed and compared with average data measured in three runs (Ave. act. data) and the minimum and maximum data measured in the three runs (min./max.). The last two data have to be taken from the protocols and to be listed. In the last column the identification number of the runs, in which the two extreme data are measured is listed (Ident. no.) The last two column are not given, with the exception of proc. nr. 1.1 as an example- The table is a proposal of how the comparison could be made. The list may not be complete in all possible cases and is concentrated on the time-, pressure- and temperature data. Other methods may be preferred to make the ability of the equipment transparent. 

Proc. Process quantity Target data Ave. act. data Ident. 

Input products are single to few and factors are mainly stable. Input factors are reflected in the recipe. Recipe in the chemical industry is a synonym for the bill-of-material in discrete parts manufacturing and includes all input products with their respective input fraction required to produce one unit of one or several output products in a production process. In chemical production, the degree of raw material consumption rates and hence the recipe factors can depend on the processing mode of the equipment, which can be employed at different utilization or throughput levels. In this case, the recipe is not composed of static input factors but of recipe functions, which express the relationship between the input consumption and the process quantity produced. 

Processes have variable throughputs with minimum process throughput TPPmm and maximum process throughput TPP max on a tons per hour basis V r,. v e IP5. Minimum and maximum process throughputs bound the process quantity as illustrated in fig. 69. 

Variable production costs cPvpc are related to process quantity on a value per ton basis in resource-specific currency Vjr,. v e /. ... 

Output product quantities are bounded by minimum output share factors ars°ftmm ar d maximum output share factors ap"ppt max measured as percentage of the total process quantity V r, 5, p) e Ips. 

The recipe function factors depend on the process utilization comparing process quantity with maximum process throughput. b pl is 0, if the recipe is static and does not change with process utilization. Otherwise the recipe factor increases with increasing process utilization. The example is also illustrated in fig. 70 and compared with a static recipe. 

Production quantities are differentiated in process, input and output quantities. The process quantity xPprocess, / r,s e IP5, teT is determined by process hours and throughput. Variable production costs v P, V r,.v e Ipi, teT depend on the process quantity. The sum of all process quantities on a resource is the resource quantity x ... 

The process quantity is split on one or multiple output products with their output quantities xp"pl, / r,s,p e Ips, teT. The total production... 

The process quantity requires input quantities from one or multiple raw... 

The process quantity ranges between minimum and maximum throughputs multiplied with the production time for the specific period. Minimum and maximum throughput boundaries are multiplied with the period-specific throughput share in order to reflect period-specific higher or lower throughput levels. 

Variable production costs for a process are equal to process quantity multiplied by variable production cost rate per ton. 

Process quantity is the basis to determine input and output product quantities. Process output product quantity has range between the output minimum and maximum share of the product related to the process quantity. 

The process output product quantities of all output products have to be equal to the total process quantity to ensure mass equality between process quantity and output products quantities. 

Assessing the safety significance of proposed changes is generally more difficult when dealing with chemical reactivity hazards. New test data may need to be obtained, and experts may need to be consulted. Changes in process quantities, rates or conditions—especially temperature—or the introduction of new or modified materials must be carefully reviewed. 

Process Quantity S/tonne ( /ton) Site Preparation Included Disposal/ Destruction of Residues Quoted Costs / tonne (S/ton)... 

Unit price (AS) Unit quantity Single-pressure process Quantity Cost/tonne per tonne (A ) Dual-pressure process Quantity Cost/tonne per tonne (A ) ... 

Figure 11. Corrected batch process— quantities of monomers in the different phases (in g) in particles Sp (1) ANP (2) in water Sw (3) ANW (4) in droplets SD (5) ANtt (6)...

Micro-mixing is important in such stirring operations where the result depends upon the size of the smallest eddies, for example dispersion processes in liquid/liq-uid systems and shear damage to microorganisms. Therefore, it is not surprising that in such tasks it is the volume related power, P/V, that counts it is an intensively formulated process quantity. 

Due to the approximate uniformity of the intensively mixed gas/liquid system and, therefore, the intensity character of the target quantity kLa, the influencing process quantities (stirrer power P, air throughput q) have to be formulated in an intensive manner as well. Now, the question arises whether, in addition to the volume-related stirrer power, P/V, the gas throughput also has be formulated as a volume-related one (q/V), or if its inclusion as the so-called superficial velocity vG = q/S (as accurate... 

The pi-space of a heat transfer characteristic of a bubble column is different to that of a mixing vessel in that the pertinent process quantity is the gas throughput q. In addition, because of the extremely large density differences in the material system G/L, gAp will also play a decisive role ... 

Figure 1.4 Material entities and process quantities for the development of a structured mathematical modelling.

Various laws restrict the values of the process quantities. These laws may represent either fundamental, empirical physicochemical relationships or experimentally identified equations (from statistical modelling or from dimensional analysis particularizations). In contrast to statistical or dimensional analysis based models [1.14], which are used to fix the behaviour of signal transformers, the models of transport phenomena are used to represent generalized phases and elementary phase connections. Here, the model equations reveal all the characterizing attributes given in the description of a structure. They include balance equations, constitutive equations and constraints. 

The third concept expression (4.36) therefore dispenses with The representation of the test data in this framework, Fig. 4.5, certainly proves that this waiver is unimportant the straight lines for water indicate a slope of 0.4-0.5 and that for salt solutions one of 0.7, as equations (4.28) and (4.29) suggest. The coupling of v both with the target quantity k a/v) and also with the process quantity (P/Vb) thus enables a simpler representation of the above dependences (a 2 parameter evaluation framework rather than a 3 parameter one). 

The amount of work used in a practical oxygen separation process is much greater than this minimum because of irreversibility. Figure 1 illustrates the process flow for one type of oxygen production cycle. The process quantities refer to separation of... 

Table 10.10 gives flow rates and compositions for the streams to and from this unit. Process quantities taken directly from Tables 10.7 and 10.8, or calculated from them in... 

The question of what is the best process for producing the product bears on the important subject of process design. The process information required for process design comprises the following (1) written description of the process (2) notes regarding special safety precautions, possible operating peculiarities, chemical reactions, and properties of materials of construction (3) knowledge of all raw materials, products, and intermediate process quantities in convenient and appropriate units ... 

Fig. 60. Dependence of required quantity of air consumed in fuel combustion on temperature of the burning process. Quantity of ain...

Some problems and concerns typical in the teaching and learning of thermodynamics do not appear in the papers cited earlier. These are a concern with a distinction between system and surroundings a concern with distinguishing state quantities from process quantities and the use of a certain type of mathematics that is specifically suited to treat non-Mnear relations between three or more variables. We therefore conclude that there is consensus among physics education researchers that the teaching of an energy concept does not require a specifically thermodynamic framework. 

Preliminary tests must be carried out to determine which of the process quantities -mixing intensity, temperature differences, supersaturation (metastable region with weak seed formation and labile, highly supersaturated region with spontaneous seed formation), seeding, mechanical loading - are of decisive influence for a particular application. If necessary, modified test apparatus must be used in individual cases. 

Some important process quantities follow [Melzer 1980] ... 

---