Design process Steps

Process integration in PRIME is based on the integration of the contextual description of the design process steps with descriptions of the tools responsible to perform these steps. A tool model is constructed in a tool modeling formalism describing its capabilities (i.e. services provided) and GUI elements (menu items, tool bars, pop-up menus etc.). Process and tool metamodels are integrated within the so-called environment metamodel (Fig. 3.3). The interpretation of environment models enables the tools to adapt their behavior to the applicable process definitions for the current process state. Thus, the user is able to better understand and control the process execution. 

Fig. 1 A roadmap of design process steps (Wac ) and their inherent elements of R ti. - u-...

Design Methods for Calciners In indirect-heated calciners, heat transfer is primarily by radiation from the cyhnder wall to the solids bed. The thermal efficiency ranges from 30 to 65 percent. By utilization of the furnace exhaust gases for preheated combustion air, steam produc tion, or heat for other process steps, the thermal efficiency can be increased considerably. The limiting factors in heat transmission he in the conductivity and radiation constants of the shell metal and solids bed. If the characteristics of these are known, equipment may be accurately sized by employing the Stefan-Boltzmann radiation equation. Apparent heat-transfer coefficients will range from 17 J/(m s K) in low-temperature operations to 8.5 J/(m s K) in high-temperature processes. 

Although a mass-flow bin is obviously preferable to a funnel-flow vessel, the additional investment generally required must be justified. Often, this can be done by the reduced operating costs. But when installation space is limited, a compromise must be made, such as providing a special hopper design and sometimes even a feeder. Certainly, with mass-flow bins the feeder is not required for flow, but it might still be used for other reasons, such as conveying the material to the next process step. 

The choice between different types of dryers is often guided by the chemicals involved and their physical properties, particularly heat sensitivity. As when selecting other equipment, the designer should first ask if the step is necessary if so, whether this is the correct or safest process step. Does the material being processed have to have all of the liquid removed Can the downstream step or customer use the material in a liquid, slurry or paste form ... 

The first and most important steps in the design process are to define clearly the purpose and function of the proposed product and to identify the service environment. Then one has to assess the suitability of a range of candidate materials. The following are generally regarded as the most important characteristics requiring consideration for most engineering components. 

The different steps of the flow and batch processes of the industrial production must be roughly described early in the design process. A more detailed description may be needed in regions w here heat and contaminants are released. Production design engineers are likely to provide the information needed. 

To control any design activity there are ten primary steps you need to take in the design process ... 

Recall from discussion of the structural design process in Section 7.2 that reconfiguration of the structure is an essential step. Reconfiguration occurs either to increase the capability or to decrease the weight because the structure has more than adequate capability. The term ca-pabi/ity s meant to include margin of safety relative to fracture, adequate resistance to buckling, sufficient difference of excitation frequency from resonant frequencies, etc. 

Table 1 Designation and Temperatures of Subsequent Processing Steps for the Two Melt Mixed Blends...

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