Furnace Plan and Layout
Fired heaters (furnaces) come in a great variety of sizes, shapes and construction. For this discussion it will suffice to distinguish between horizontal and vertical furnaces. The term “horizontal” and “vertical” refers to the position of the tubes in the radiant section.
The vertical furnace not only saves space, but its piping is simpler and repairs are easier. All tubes can be removed vertically from the top platform where there is little piping interference, except for the top connections. A circular tube arrangement also gives the piping designer additional freedom in orienting the inlet and outlet nozzles. With horizontal furnaces, greater care is required to avoid obstructing the tubes and to allow for erection of maintenance scaffolding.