Читать книгу Young Engineer's Guide - J. V. Rohan - Страница 8

Table of Contents

Q. How is a locomotive or fire box boiler constructed?

A. The ends of a cylindrical shell are continued straight down upon the sides, and enclosed to form a rectangular structure in its lower portion and conformed to the curvature of the cylindrical shell at the top. In the rectangular portion is secured a fire box, separated from the sides and ends by water spaces called “water legs,” and having its top which is called the “crown sheet” about the center of the cylindrical shell. An opening is formed in both sheets in rear end of the fire box door frame. The cylindrical shell has heads riveted at both ends. These heads have numerous flues open at both ends put in. All the flat surfaces are stayed to each other at suitable intervals, and the crown sheet is stayed from the shell. The fuel is thrown in through the door at the rear, and the products of combustion are conveyed to further extremity through the tubes or flues. It is furnished with hand-holes for cleaning and a steam dome. There are two different styles of fire boxes on Locomotive Boilers, the round bottom fire box in which the water circulates under the grates, and the square open bottom fire box. Both kinds are used extensively.

Freeman Locomotive Boiler.

Sectional View Freeman Locomotive Boiler.

Q. What advantages have the locomotive or fire box boiler?

A. It is entirely self-contained, generates steam very rapidly, is economical in space, and needs no elaborate foundation.

Q. What disadvantages has the locomotive or fire box boiler?

A. Expensive first cost, and difficulty in cleaning, especially where impure feed water is used.