Heat-Transfer Calculations

Using fire models, locations of equipment, heat transfer calculations, and environmental qualifications of the equipment, it is possible to estimate the time to failure. Fragility cuives that relate fire durations and equipment damage while considering the probability of fire suppre.ssion are produced to relate to the overall PSA. These fragility curves and their use is simitar the methods ised for seismic analysis. [Pg.199]

Useful dimensionless groups for heat transfer calculation are ... [Pg.94]

Equivalent tube diameter for shell-side heat transfer calculations is used by permission from Kem and Kraus. ... [Pg.104]

The heat transfer calculations are presented by the several manufacturers, and due to the proprietary nature of the surface areas, are available for various arrangements. It is advisable to obtain specific help. [Pg.235]

Fair reports that the data for mass transfer in spray, packed, and tray columns can be used for heat-transfer calculations for these columns. The pressure drop in these types of columns is usually quite low. [Pg.249]

In transporting this water through insulated pipes to the process equipment, it is good practice to allow a 2°F temperature rise when planning heat transfer calculations. [Pg.295]

For heat-transfer calculations, Kern (1950) gives a rough rule of thumb for organic liquid mixtures ... [Pg.320]

The data available in the literature up to 1973 have been reviewed by Jamieson el al. (1975). The Weber equation (Weber, 1880) can be used to make a rough estimate of the thermal conductivity of organic liquids, for use in heat-transfer calculations. [Pg.321]

It is the full wetted perimeter that determines the flow regime and the velocity gradients in a channel. So, in this book, de determined using the full wetted perimeter will be used for both pressure drop and heat transfer calculations. The actual area through which the heat is transferred should, of course, be used to determine the rate of heat transfer equation 12.1. [Pg.664]

The basic formulas for heat transfer calculations are for thermal conductivity between the water layers ... [Pg.298]

The equipment requirements that we have determined are well within the realm of technical feasibility and practicality. The heat transfer requirements are easily attained in equipment of this size. The fact that some of the heat transfer requirements are positive and others negative indicates that one should probably consider the possibility of at least partial heat exchange between incoming cold feed and the effluent from the second or third reactors. The heat transfer calculations show that the sensible heat necessary to raise the cold feed to a temperature where the reaction rate is appreciable represents a substantial fraction of the energy released by reaction. These calculations also indicate that it would be advisable to investigate... [Pg.359]

Optical designers and specialists in heat transfer calculations in the chemical engineering and mechanical engineering sciences are familiar with the mathematical construct known as The Equation of Radiative Transfer, although most chemists and spectroscopists are not. The Equation of Radiative Transfer states that, disregarding absorbance and scattering, in a lossless optical system... [Pg.142]

Heat transfer calculations show that when 15% of the coil has been traversed, the oil temperature is within 5°F of the lead bath. It will be assumed that no significant conversion has occurred in the preheat section and that the reaction is substantially isothermal in the remaining 85% of the reactor volume. [Pg.235]

In well-developed fires, the convective heat fraction is typically measured at more than about 65% of the total heat release rate (Heskestad, 2002). This heat is carried away by the plume above the flames. Prediction of plume velocity and temperatures above the flames serve as the basis for convective heat transfer calculations where overhead equipment exists. Widely used fire plume theory assumes a point source origin, and uniformity throughout the plume relative to air density, air entrainment, velocity profile, and buoyancy. [Pg.68]

More sophisticated, computerized heat transfer calculation techniques are available where specific scenarios require detailed analysis (Idling et al., 1977 Paulsson, 1983). These techniques involve the use of multidimensional finite element programs. [Pg.79]

Simple heat transfer calculations i. e. using sources like Ref [20], indicate that even uninsulated lines are not a severe problem in most spectroscopic applications. With insulated 1/8, 1/16, and 1/32 inch stainless steel and PEEK tubing, with a flow velocity of ca. 0.1-lm s and driving force of 50 °C between... [Pg.156]

The second method uses dimensionless numbers to predict scale-up parameters. The use of dimensionless numbers simplifies design calculations by reducing the number of variables to consider. The dimensionless number approach has been used with good success in heat transfer calculations and to some extent in gas dispersion (mass transfer) for mixer scale-up. Usually, the primary independent variable in a dimensionless number correlation is Reynolds number ... [Pg.74]

G. M. Dusinberre, Heat Transfer Calculations by Finite Differences, Second Edition, International Textbook, Scranton, PA., 1961. [Pg.227]

Equation (67) is the basis of practical heat transfer calculations. In order to use it to solve problems, additional information is required about the total heat transfer rate Q and the production rate QfCR. The first is usually expressed in terms of a heat transfer coefficient analogous to the friction factor,... [Pg.263]

If we can expect that the eddy momentum and energy transport will both be increased in the same proportion compared with their molecular values, we might anticipate that heat-transfer coefficients can be calculated by Eq. (5-56) with the ordinary molecular Prandtl number used in the computation. It turns out that the assumption that Pr, = Pr is a good one because heat-transfer calculations based on the fluid-friction analogy match experimental data very well. For this calculation we need experimental values of C/ for turbulent flow. [Pg.242]

The analogy between heat transfer and fluid friction [Eq. (5-56)] may also be used when the friction coefficient is known. Summarizing the relations used for high-speed heat-transfer calculations ... [Pg.255]

How is the heat-transfer coefficient defined for high-speed heat-transfer calculations ... [Pg.259]

Up to this point, the gas-radiation calculation methods discussed were concerned only with black surfaces exchanging heat with the gas. In many engineering applications the enclosure walls are dirty and sooty, the wall emissivity is very high, and the heat-transfer calculation by Eq. (8-53) may be a reasonable... [Pg.420]

It is of interest to compare the heat transfer calculated above with that obtained by assuming surfaces 2, 3, and 4 uniform in temperature and radiosity. Equation (8-41) applies for this case ... [Pg.452]

In this chapter v.e have examined several means for analyzing radiation heat transfer. The gray-body assumption, although not strictly correct, is a viable method for performing heat-transfer calculations. Assumptions of uniform ra-diosity and irradiation over surfaces are also not strictly correct but provide an approximation which is usually well within the accuracy of knowledge of surface proper , e. (n Table 8-6, we present a tabular summary of a few formulas which are ofte . used. [Pg.471]

B Dunkle, R. V. Geometric Mean Beam Lengths for Radiant Heat Transfer Calculations," J. Heat Transfer, vol. 86, p. 75, February 1964. [Pg.490]

The cross-sectional area of heat transfer A in Eq. (1) can vary appreciably along the length of the heat-transfer path x. Therefore, the shape of the solid through which heat is flowing must be known before Eq. (1) can be integrated to give Eq. (2). The exact value for A based on the limiting areas A, and A follows for three cases commonly encountered in heat-transfer calculations ... [Pg.587]

The following values of overall heat-transfer coefficients are based primarily on results obtained in ordinary engineering practice. The values are approximate because variation in fluid velocities, amount of noncondensable gases, viscosities, cleanliness of heat-transfer surfaces, type of baffles, operating pressure, and similar factors can have a significant effect on the overall heat-transfer coefficients. The values are useful for preliminary design estimates or for rough checks on heat-transfer calculations. [Pg.600]

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