Boiler draught by Pratt Harry Keay

Author:Pratt, Harry Keay
Language: eng
Format: epub
Tags: Steam-boilers, Mechanical draft
Publisher: New York, D. Van Nostrand Co.
Published: 1911-03-25T05:00:00+00:00

Digitized

by Google

DEAUGHT FOE LAND INSTALLATIONS 99

attached to a Babcock & Wilcox boiler. The air heater or heat economiser is seen behind the back wall of the boiler setting, in the left-hand view. The right-hand view clearly shows the two fans, the smaller of which deals with the cold air, while the larger one controls the hot gases.

Digitized

E 2

by Google

CHAPTER X

THE APPLICATION OP MECHANICAL DRAUGHT IN MARINE PRACTICE

The matter contained in the foregoing chapters relating to the combustion of fuel, and methods of producing the necessary draught for it, has been considered from the standpoint of land installations.

Perhaps it would not be out of place to devote a few lines now to mechanical draught apparatus on board ship.

The calculations referring to land installations are equally applicable to marine work. A very simple method of arranging forced draught for a battery of marine boilers is the plenum system. In this, the boiler room is entirely closed, the air therein being maintained, by means of an open running fan, at a higher pressure than the atmosphere, usually about 2 inches. The fan is placed on one side of the bulkhead and the engine on the other, by which arrangement the fan draws its air from the atmosphere and discharges it from its periphery into the boiler-room. This arrangement is seen in Fig. 23, which is a drawing illustrating a single-acting engine coupled up to a fan of this type. It will be noted that the latter has no casing, consequently the mechanical efiBciency of this design is not very high. When owners are willing to go to the expense, it is better to employ a steel-cased fan, either placed entirely outside the stoke-

Digitized

by Google

APPLICATION OF MECHANICAL DEAUGHT 101

hold and discharging into it through a duct, or else to have the casing bolted directly against the bulkhead, the relative position of the fan and engine being exactly

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.