Category Archives for General Information
Natural Draft. The majority of fired heaters in process use have natural draft. A stack of appropriate height provides the draft needed to draw in air at the burners; move flue gas through the firebox, convection section and stack; and … Continue reading
The firebox is a cylinder submerged in the process fluid or in an indirect heat transfer medium, usually oil or water. Flue gas from the burner flows through the firebox and then through “fire tubes,” also submerged, making one or … Continue reading
There are three ways the radiant coil can be fired: • single fired with process fluid in tubes (Figures 100-2, 100-3, 100-4 and 100-8) • double fired with process fluid in tubes (Figures 100-5, 100-7, and 100-9) • with the … Continue reading
Four common tube coil layouts are: • vertical in series • vertical in parallel • horizontal in series • horizontal in parallel Vertical in Series. This is common in vertical cylindrical heaters (Figure 100-2). There may be two or more … Continue reading
This shape is often found in small utility heaters or in producing or pipeline operations. Figure 100-6 shows a convection (only) heater. Hot gas from the burners is immediately mixed with a large volume of cooler recirculating flue gas. The … Continue reading
This shape is often used in steam reforming heaters because it provides even heating along the length of the catalyst-filled tubes. There may be two or three terraces. Burners fire up along the walls.
A box heater with “jump headers” is a way to get uniformity of heat input to multiple tube passes.
A box heater is rectangular, or nearly so, in any cross-section. The two walls with the longer horizontal dimension are usually called the sides; the others are the ends. The box may be fired by burners on one or both … Continue reading
This is a common type, chosen mainly for its low cost and space requirement. The tubes are almost always vertical; a helical coil is rarely seen. Because of its symmetry, this layout easily accommodates multiple tube passes. (Figure 100-2 shows … Continue reading
Liquid phase only. These are mild services, and coking of tubes is seldom of concern. Heaters for circulating hot oil systems and pipeline heaters are in this category. These furnaces are usually single tube pass design. Vapor phase only. The … Continue reading