Читать книгу Young Engineer's Guide - J. V. Rohan - Страница 9

Table of Contents

Q. Describe the construction of a Return Flue Boiler?

A. It has a cylindrical shell, with heads riveted at each end, in which are placed a large main flue, and a number of small flues or tubes, open at both ends. The top row of flues is placed below the water line. One end of the main flue is used for the fire box, into which the fuel is thrown through door at back end and the products of combustion pass forward through this main flue to an ample smoke box in front end, and return through the smaller flues or tubes to smoke box at rear end, which is connected to the smoke stack. They are generally supplied with steam dome and mud drum, and are used extensively in the construction of traction engines where straw is used for fuel. They are also furnished with several hand-holes placed in proper places for cleaning the boiler.

Sectional View J. I. Case Return Flue Boiler.

Q. What are the advantages of this style of boiler?

A. Large heating surface, easily repaired and cleaned, simplicity of construction and compactness.

REYNOLDS CORLISS CONDENSING AND NON-CONDENSING ENGINE.

This engine has a massive, peculiarly constructed frame, being cast in two parts. The forward part contains the main pillow block bearing, and the part in which the cross-head runs is cylindrical in shape, and has bored Guides, and large lateral openings.

The crank is a large disc plate, and the large heavy fly-wheel serves the double purpose of a drive pulley and balance wheel.

The cylinder is supplied with four valves, two at the top and two at the bottom, and directly upon the bore of the cylinder. The two at the top are the steam valves, the two at the bottom are exhaust valves, and receive their motion from a single eccentric acting through the medium of a wrist plate or vibrating disc, from which the valve connections radiate. The valve being independently adjusted, the commencement, extent and rapidity of the movement of each can be most accurately arranged. The steam valves are controlled by the Governor, which, being very sensitive to the variation of load, allows just the required amount of steam to enter the cylinder to keep up the uniform speed. The exhaust valves being at the lower ends of the cylinder, at the clearance space, the water of condensation is allowed to escape in the most thorough manner, without the use of cylinder cocks or other devices.

This style of engine is intended for all purposes, but is especially adapted to heavy and continuous work and where the conditions call for an engine capable of working under a high steam pressure, also when the work is of an intermittent character.

Reynolds Corliss “1890” Engine—Front View.