Heat exchangers multipass

Ahmad, S., LinnhoflF, B., and Smith, R., Design of Multipass Heat Exchangers An Alternative Approach, Trans. ASME, J. Heat Transfer, 110 304, 1988. 

In the field of heat transfer, a good example of this category of shortcut design method is the famous F correction factor to correct the log mean temperature difference of shell and tube heat exchangers for deviations from true countercurrent flow. For multipass heat exchangers, the assumptions are ... 

Using the data of Example 9.1, calculate the surface area required to effect the given duty using a multipass heat exchanger in which the cold water makes two passes through the tubes and the hot water makes a single pass through the shell. 

Underwood, A.J.V. . /. Inst. Petrol. Teclmol. 20 (1934) 145. The calculation of the mean temperamre difference in multipass heat exchangers. 

Liu, Y. A., Pehler, F. A. and Cahela, D. R., "Studies in Chemical Process Design and Synthesis VII. Systematic Synthesis of Multipass Heat Exchanger Networks," AIChE J., in press (1983). 

Select and apply the appropriate heat-transfer formula. When cooling a batch with an external 1-2 multipass heat exchanger and a nonisothermal cooling medium, the following equations apply ... 

Related Calculations. This procedure can also be used for batch heating with external 1 -2 multipass heat exchangers and nonisothermal heating media. The equation in such a case is... 

Use equation for 1-2 multipass. The mean temperature difference for a 1-2 multipass heat exchanger can be calculated from the equation... 

Related Calculations. Mean temperature differences for multipass heat exchangers may also be calculated by using appropriate correction factors for the log mean temperature difference for countercurrent flow... 

Related Calculations. The thermal effectiveness of a 2-4 multipass heat exchanger can be determined from Fig. 7.16. The value of R for exchangers that have one isothermal fluid is zero, for both 1-2 and 2-4 multipass heat exchangers. 

EXAMPLE 11-9 Cooling Hot Oil by Water in a Multipass Heat Exchanger... 

A simplified schematic of a typical multitubular reactor design is shown in Fig. 15. The mechanical design generally parallels that used for multipass heat exchangers except that the scale is often significantly larger. It consists of a bank of parallel tubes whose nominal inside diameter typically varies from 25 to... 

Batch Heating External Heat Exchanger (1-2 Multipass Heat Exchangers), Non-isothermal Heating Medium... 

The procedure used for batch heating with external 1-2 multipass heat exchangers with non-isothermal heating media involves using the same heat balance as defined by the following equation ... 

The same procedure can be used as in 1-2 multipass heat exchangers. The equation for batch heating with external 2-4 multipass heat exchangers and non-isothermal heating media is... 

With the growth of flow rate from low values, the elements of the reactive mass with the longest residence time are carried out from the reactor, i.e. those that have reacted to the maximal depth and have the maximal viscosity. Instead, the reactor is refilled with a fresh mixture of minimal viscosity. The effect of non-monotony of the P(Q) curve in isothermal flow of polymerizing liquid was independently discovered in Refs. [34, 35], and moreover, in Ref. [34] its qualitative experimental confirmation (instabilities during the operation of the corresponding multipass heat exchangers) was reported. 

Nagle, W.M., Mean Temperature Differences in Multipass Heat Exchangers, Ind. Eng. Chem., 25,604-609 (1933). 

Underwood, A.J.V., The Calculation of the Mean Temperature Difference in Multipass Heat Exchangers, J. Inst. Petroleum TechnoL, 20, 145-158 (1934). 

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