Heater tubes cross-section

Figure 21.3 Heater tube cross section close to failure.

Fire 1.4. Steam boiler and furnace arrangements. [Steam, Babcock and Wilcox, Barberton, OH, 1972, pp. 3.14, 12.2 (Fig. 2), and 25.7 (Fig. 5)]. (a) Natural circulation of water in a two-drum boiler. Upper drum is for steam disengagement the lower one for accumulation and eventual blowdown of sediment, (b) A two-drum boiler. Preheat tubes along the Roor and walls are cormected to heaters that feed into the upper drum, (c) Cross section of a Stirling-type steam boiler with provisions for superheating, air preheating, and flue gas economizing for maximum production of 550,000 Ib/hr of steam at 1575 psia and 900°F. 

Ag (total internal cross section area of 2173 tubes) = 39.3 sqft Aa (clear area between tubes for crossflow of air) = 70 sqft Air temperature entering air heater = 80°F... 

Fig. 5.1. Cross-sectional view of the small liquid helium tank including the sample mounting for the operation below (a) and above 4.2 K (b). 1 sample 2 sample holder 3 clamping screw 4 copper ring for wire heat sink 5 thermal shield 6 liquid helium tank 7 clamping ring 8 indium seal 9 liquid helium tubes 10 temperature sensor 11 heater 12 copper block 13 nylon disk 14 lid for liquid helium tank. (From Ref [5.7].)...

The tube size, the number of tubes per row, the area per row and the minimum cross-sectional area for flue gas flow are considered in this rating procedure. Usually, in fired heaters the tube size in the radiant section is the same as in the convection section, and the number of tubes per row is such that the flue gas rate is about or below 15 feet per second. The area per row is the exposed area per tube times the number of tubes. The minimum cross-section area for flue gas flow is the total cross-sectional area of the convection section less the projected area of one row of tubes. 

Figure 5.2 Top Sketch of a jet separator device used to couple a packed column GC to a mass spectrometer. The dimensions are typically d = 100 p.m and d2 and d3 both 250-300 p.m. The two tubes leading to the MS and from the GC, and drawn down to small apertures, must be accurately aligned. Such devices are normally fabricated of an inert material such as borosilicate glass. Bottom Schematic diagram of an experimental jet separator designed with an adjustable inter-jet gap, in (A) cross-section and (B) axial view, (a) delivery capillary connected to transfer line from GC (b) gap adjustment threaded disk (c) nozzles (d) window (e) receiving capillary connected to the ion source (f) gap zero-setting threaded disk (g) expansion chamber (h) vacuum port (i) brass body of device (j) cartridge heater (not visible in cross-section). Reproduced from Pongpun, J. Mass Spectrom. 35, 1105 (2000), with permission of John Wiley Sons, Ltd.

FIG. 27-51 Representative types of fired heaters a) vertical-tube cylindrical with cross-flow-convection section (h) horizontal-tube cabin (c) vertical cylindrical, helical coil, from Berman, Chem. Eng. 85 98-104, June 19, 1978.)... 

Figure 3-20. Vertical-tube-fired heaters con be identified by the vertical arrangement of the radiant-section coil, (a) Vertical- lindrical all radiant, (b) Vertical-cylindrical helical coil, (c) Vertical-cylindrical, with cross-flow-convection section. d) Vertical-cylindrical, with integral-convection section, (e) Arbor or wicket type, (f) Vertical-tube, single-row, double-fired. [From Chem. Eng, 100-101 (June 19, 1978).]...

Schematic elevation sections of a vertical cylindrical, cross-tube convection heater a horizontal-tube cabin heater and a vertical cylin-drical, helical-coil heater are shown in Fig. 24-43. The seven basic designs and some variations of them are pictured and described in the reference cited above and by R. K. Johnson [Combustion 50(5) 10-16, November 1978],...

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