Vertical thermosiphon reboiler

Figures 10-96A-E illustrate horizontal and vertical thermosiphon reboiler flow arrangements.

Figure 10-97B. Heat transfer data of reboilers boiling a hydrocarbon mixture in horizontal and vertical thermosiphon reboilers compared to a kettle reboiler. (Used by permission Yilmaz, S. B. Chemical Engineering Progress, V. 83, No. 11, p. 64, 1987. American Institute of Chemical Engineers. All rights reserved.)...

Figure 10-105. Nozzle connections for vertical thermosiphon reboilers.

The vertical thermosiphon reboiler is a popular unit for heating distillation column bottoms. However, it is indeed surprising how so many units have been installed with so little data available. This indicates that a lot of guessing, usually on the very conservative side, has created many uneconomical units. No well-defined understanding of the performance of these units exists. Kern s recommended procedure has been found to be quite conservative on plant scale units yet it has undoubtedly been the basis for more designs than any other single approach. For some systems at and below atmospheric pressure operation, Kern s procedure gives inconsistent results. The problem is in the evaluation of the two-phase gas-liquid pressure drop under these conditions. 

This method for vertical thermosiphon reboilers is based on semi-empirical correlations of experimental data and is stated to predict heat transfer coefficients 30 percent, which is about the same range of accuracy for most boiling coefficient data. The advantage of this method is that it has had significant design experience in the industry to support it. It is also adaptable to other types of reboilers used in the industry. See Figures 10-110 and 10-111. 

Physical properties at expected operating temperatures. See Figure 10-112 for temperature-pressure effects in vertical thermosiphon reboilers. 

The article of Fair and Klip presents a detailed analysis of the necessary design features and equations for horizontal kettle reboilers, horizontal thermosiphon reboilers, and vertical thermosiphon reboilers. Other useful references on reboilers are 185,186,188,190,192,194,195,196,197, and 201. 

Equivalent Feet of Inlet and Outlet Piping Vertical Thermosiphon Reboiler... 

Vertical Thermosiphon Reboiler Comparison Effect of Pressure Drop and Pipe Size on Selection... 

Figure 10-122. Overall AT at maximum flux vertical thermosiphon reboilers. (Used by permission Hajek, J. D. Private communication. Deceased.)...

General Guides for Vertical Thermosiphon Reboilers Design... 

Johnson, A. 1., Circulation Rates and Over-All Temperature Driving Forces in a Vertical Thermosiphon Reboiler, presented at AlChE Heat Transfer Sym., Louisville, KY, Mar. 20 (1955). 

Pressure Drop on the Tube Side of a Vertical Thermosiphon Reboiler 193... 

Application of the Effectiveness and the 9 Method 182 Sizing an Exchanger with Radial Finned Tubes 193 Pressure Drop on the Tube Side of a Vertical Thermosiphon Reboiler 193... 

Figure 12.60. Vertical thermosiphon reboiler, liquid, and vapor flows.

The tube lengths used for vertical thermosiphon reboilers vary from 1.83 m (6 ft) for vacuum service to 3.66 m (12ft) for pressure operation. A good size for general applications is 2.44 m (8 ft) by 25 mm internal diameter. Larger tube diameters, up to 50 mm, are used for fouling systems. 

A fixed tube sheet will be used for a vertical thermosiphon reboiler. From Figure 12.10, shell diametrical clearance = 14 mm,... 

Make a preliminary design for a vertical thermosiphon reboiler for the column specified in Example 11.9. Take the vapor rate required to be 36kmol/h. 

Use 25 mm i.d., 2.5 m long tubes, a popular size for vertical thermosiphon reboilers. 

Make a preliminary mechanical design for the vertical thermosiphon reboiler for which the thermal design was done as Example 12.9 in Chapter 12. The inlet liquid nozzle and the steam connections will be 50 mm inside diameter. Elat-plate end closures will be used on both headers. The reboiler will be hung from four bracket supports, positioned 0.5 m down from the top tube plate. The shell and tubes will be of semi-killed carbon steel. 

Vertical Thermosiphon Reboilers Vertical thermosiphon reboilers operate by natural circulation of the hquid from the still through the downcomer to the reboiler and of the two-phase mixture... 

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