Cabin-fired heaters

Cabin fired heaters inciude a tough metai sheii that surrounds a firebox, convection section, and stack. Cyiindricai furnaces use a tube-shaped firebox to transfer heat energy into a moving liquid. A box furnace has the same standard components as a cabin furnace. The burners can be arranged on the bottom or on the sidewaii. The tube arrangement depends on how the burners line up. 

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 3-21. Six bask designs used in horizontal-lube fired heaters. Radian section coil is horLmtai. (a) Cabin, (b) Two-cell box. (c) Cabin with dividing bridgewall, (d) End-fired box. e) End-fired box, with side-mounted convection section, (f) Horizontal-tube, single-row, double-h red. [From Chem. Eng., 102-103 (June 19, 1978).]...

Fire-tube heaters—furnaces consisting of a battery of tubes that pass through a firebox. Fired heaters or furnaces are commercially used to heat large volumes of crude oil or hydrocarbons. Basic designs include cylindrical, cabin, and box. 

A fired heater or furnace is used to heat large quantities of hydrocarbons for industrial use in a distillation system or reactor. Fired heaters are characterized by three basic designs cabin, cylindrical, and box. The basic components of a furnace include shell, refractory lining, burners, radiant tubes, convective tubes, damper, stack, and firebox. Air and fuel are proportionally balanced as temperatures in the furnace are held constant. Figure 7-12 shows the two standard symbols used for a fired heater or furnace and a boiler. 

A furnace, or fired heater, is a device used to heat up chemicals or chemical mixtures. Furnaces consist essentially of a battery of fluid-filled tubes that pass through a heated oven. These devices provide a critical function in the daily operation of the chemical processing industry. Process heaters are more technically defined as combustion devices designed to transfer convective and radiant heat energy to chemicals or chemical mixtures. These heaters are typically associated with reactors or distillation systems. Process heaters come in a wide variety of shapes and designs, but the basic styles include cabin, box, and cylindrical. The various parts of a process heater include a radiant section and burners, a bridgewall section, a convection section and shock bank, and a stack with damper control. Modern control instrumentation is used to maintain these rather large and elaborate systems. 

Honzontal-tube cabin heaters position the tubes of the radiant-section-coil horizontally along the walls and the slanting roof for the length of the cabin-shaped enclosure. The convection tube bank is placed horizontally above the combustion chamber. It may be fired From the floor, the side walls, or the end walls. As in the case of its vertical cylindrical counterpart, its economical design and high efficiency make it the most popular horizontal-tube heater. Duties are 11 to 105 GJ/h (10 to 100 10 Btu). 

Fig. 4.25. Forced draft heater for petro-chem processing—may be cylindrical with one burner as shown, or a circie of vertically up-fired, high-velocity type H burners (fig. 6.2) or rectangular (a cabin heater) with rows of up-fired burners, or rows of side-fired type E flat-flame burners, shown in fig. 4.26 and 6.2.

Type 321 is similar to 304 but with titanium addition five times the carbon content that reduces carbide precipitation during welding and in 425-815 C service. It has excellent corrosion resistance toward most chemicals and oxidation resistance up to SIS C. Aircraft exhaust manifolds, boiler shells, process equipment, expansion joints, cabin heaters, fire walls, flexible couplings, pressure vessels. 

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