Standard design parameters

TABLE XK-2. STANDARD DESIGN PARAMETERS FOR THE CORE MODEL... 

Figure 1.12 Standard design parameters for a microbiai bioreactor vessei with typicai vaiues inciuded. Parameters may vary based on the specific appiication.

What furnace engineers most need is a closed-form solution of the problem, theoretically sound in structure and therefore containing a minimum number of parameters and no empirical constants and, preferably, physically visuaHzable. They can then (1) correlate data on existing furnaces, (2) develop a performance equation for standard design, or (3) estimate performance of a new furnace type on which no data are available. 

Much of the experience and data from wastewater treatment has been gained from municipal treatment plants. Industrial liquid wastes are similar to wastewater but differ in significant ways. Thus, typical design parameters and standards developed for municipal wastewater operations must not be blindly utilized for industrial wastewater. It is best to run laboratory and small pilot tests with the specific industrial wastewater as part of the design process. It is most important to understand the temporal variations in industrial wastewater strength, flow, and waste components and their effect on the performance of various treatment processes. Industry personnel in an effort to reduce cost often neglect laboratory and pilot studies and depend on waste characteristics from similar plants. This strategy often results in failure, delay, and increased costs. Careful studies on the actual waste at a plant site cannot be overemphasized. 

Type tests are conducted on the first enclosure of each voltage, current rating and fault level to demonstrate compliance with electrical and constructional design parameters. The tests provide a standard reference for any subsequent enclosure with similar ratings and constructional details. The following tests may be conducted to demonstrate verification of the following ... 

Commercially available thermal oxidizer systems are pre-engineered, that is, the equipment is designed on the principle that in order for the equipment to be competitive in the marketplace, then a series of products of fundamentally standard designs are tailored to the application by changing some of the parameters as dictated by the requirements. This is not always the case with other pollution control systems, as oftentimes custom built-systems are specified. Since thermal oxidation equipment has a burner, the designs require controls for safety and operation. 

Equation 14.11 introduces the notion of radius of influence, which is one of the important design parameters of S VE systems. Theoretically, the maximum radius of influence of a well is the distance at which the pressure becomes equal to the ambient atmospheric pressure, i.e., P = Patm. In practice, Pj is determined as the distance at which a sufficient level of vacuum still exists to induce airflow, e.g., 1% of the vacuum in the extraction well.912 The extraction wells are usually constructed using pipes with a standard radius, e.g., Pw = 5.1 cm (2 in.) or 10.2 cm (4 in.), and the vacuum applied in the wells typically ranges from 0.05 to 0.15 atm, i.e., Pw = 0.95-0.85 atm.9 12 If the vacuum required in the radius of influence is 1% of the vacuum in the extraction well, the... 

Pesticide regulation makes use of measurements of specific fate and effects properties, as specified in laws such as the US Federal Insecticides Fungicides and Rodenticides Act (FIFRA). Studies are conducted according to relatively standardized designs. Particularly in this type of situation, it seems reasonable to develop default distributions for particular variables, as measured in particular, standardized studies. Default assumptions may relate to default distribution types, or default distribution parameters such as a coefficient of variation, skewness, or knrtosis. Default distributions may be evaluated in comparative studies that draw from multiple literature sources. Databases of pesticide fate and effects properties, such as those maintained by the USEPA Office of Pesticide Programs, may be useful for such comparative analyses. 

For each interconnection of an intrinsically safe circuit with an associated apparatus a proof of intrinsic safety - i shall be performed on the basis of the safety-related maximum values. As far as the simple standard design given in this example (Fig. 6.218) is concerned, it is assumed that the associated apparatus only - the Ex i-isolator - can feed electrical power into the intrinsically safe circuit. Therefore the safety-related parameters are marked as out-parameters with the subscript o. On the other side, the intrinsically safe apparatus may consume electrical power only. Its values are marked as in-parameters, subscript i. ... 

No formal optimization of the parameters was attempted. Instead, individual feed, operating, and design parameters were perturbed around a standard set to assess their influence on the computed performance parameters. 

In solid-liquid systems the size and shape of the baffles are important design parameters. The standard baffling is illustrated in Fig 7.1. As the solid concentration increases and the viscosity becomes high, narrower baffles (approximately 1/24T) placed a distance from the wall, should be used. This design is normally employed to avoid permanent settling of particles in the low velocity zones. In some processes such fillets (settled particles) can nevertheless be advantageous for the power consumption. 

Our objective is to determine the effects of each of these factors and thus establish optimum conditions for manufacture. An experimental design to optimize all of them would require at least 36 experiments (the number of coefficients in the second order model) A standard design for optimizing on 7 parameters would require over 50 experiments. This is rather too many. Instead it was decided to try to find out initially which factors affect the yield and require further study, in order... 

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