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Reboiler heat transfer

Compute condenser and reboiler heat-transfer rates from Eqs. (13-159) and (13-160). [Pg.1340]

A kettle reboiler heat transfer area 25 m2, carbon steel shell and tubes, operating pressure 10 bar. [Pg.280]

Calculate the reboiler heat transfer area using Equation 7.10... [Pg.196]

Insufficient circulation is usually caused by plugging, a leaking reboiler preferential baffle or draw pan, or by insufficient liquid head (alternatively, excessive pressure drop in the reboiler loop). Leakage across the preferential baffle is implied when the bottom sump level influences reboiler heat transfer rate despite the presence of a baffle. [Pg.446]

Temperature pinch. A temperature pinch is process temperature approaching the heating medium temperature. It therefore occurs only when the reboiler AT is small. A temperature pinch lessens reboiler heat transfer. Two mechanisms are usually responsible for temperature pinches ... [Pg.448]

Liquid level. When liquid level falls below the top of the bundle, the unflooded tubes heat vapor rather than perform nucleate boiling. Since vapor heating has a much lower heat transfer coefficient than nucleate boiling, reboiler heat transfer suffers. Further, the tube wall temperature in the unflooded portion approaches the heating fluid temperature, which may overheat tube metal. For these reasons, it is important to maintain the desirable liquid level in the reboiler. [Pg.459]

Olefins Demethanizer Condensate seal was lost on a vertical thermoeiphon reboiler causing loss of heat transfer. Losing reboiler condensate seal can lower reboiler heat transfer rate. [Pg.663]

A simple recalibration of the reboiler temperature controller rectified this problem. Incidentally, operating a triethylene glycol reboiler at 375°F-400°F does not necessarily result in a noticeable increase in glycol degradation. The trick is to keep the glycol filters in good repair. Dirty glycol fouls the reboiler heat-transfer tube. This in turn causes hot spots on the heat-transfer surface, which accelerates thermal decomposition. [Pg.216]

The idea of the condensate seal is quite familiar to operators. For engineers lacking field experience, it is a surprising concept. Figure 18-10 shows a water level in the channel head. This is the condensate seal. Once this level drops out of the channel head and steam starts blowing through the control valve, the reboiler heat-transfer duty is drastically reduced. [Pg.453]

Reboiler Heat transfer coefficient Ur 0.568 kJ K Temperature difference ATr 34.8 K Condenser Heat transfer coefficient Uc 0.852 kJ K m Temperature difference ATc 13.9 K Energy cost 4.7 (lO kJ) Payback period Ppay 3.0 years ... [Pg.42]


See other pages where Reboiler heat transfer is mentioned: [Pg.198]    [Pg.197]    [Pg.198]    [Pg.2588]    [Pg.139]    [Pg.446]    [Pg.446]    [Pg.459]    [Pg.122]    [Pg.361]    [Pg.406]    [Pg.406]   
See also in sourсe #XX -- [ Pg.434 , Pg.436 , Pg.440 , Pg.442 , Pg.443 , Pg.445 , Pg.449 , Pg.455 , Pg.456 , Pg.459 , Pg.662 , Pg.663 ]




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