Horizontal Ruturn Tubular Boiler

Horizontal Return Tubular Boiler

In addition to operating portable boilers such as the Scotch marine and vertical fire-tube
boilers, the UT must also be able to operate stationary boilers, both in the plant and in
the field. A stationary boiler can be defined as one having a permanent foundation and
not easily moved or relocated. A popular type of stationary fire-tube boiler is the
horizontal return tubular (HRT) boiler shown in Figure 9-16.
The initial cost of the HRT boiler is relatively low, and installing it is not too difficult. The
boiler setting can be readily changed to meet different fuel requirements—coal, oil,
wood, or gas. Tube replacement is also a comparatively easy task since all tubes in the
HRT boiler are the same in size, length, and diameter.
The gas flows in the HRT boiler from the firebox to the rear of the boiler. It then returns
through the tubes to the front where it is discharged to the breaching and out the stack.
The H RT boiler has a pi tch o f 1 t o 2 i nches to t he r ear t o allow sediment to se ttle
toward t he r ear n ear the bottom bl owdown co nnection. The fusible pl ug i s located 2
inches above the top row of tubes. Boilers over 40 inches in diameter require a manhole
in the upper part of the shell. Those over 48 inches in diameter must have a manhole in
the lower as well as in the upper part of the shell. Do not fail to familiarize yourself with
the location of these and other essential parts of the HRT boiler. The knowledge you
acquire will definitely help in the performance of your duties with boilers.