Practical instructions relating to the construction and use of the steam engine indicator by Crosby Steam Gage & Valve Company & Miller Edward Furber 1866-

Author:Crosby Steam Gage & Valve Company & Miller, Edward Furber, 1866-
Language: eng
Format: epub
Tags: Indicators for steam-engines
Publisher: Boston, Crosby Steam Gage and Valve Company
Published: 1919-03-25T05:00:00+00:00

Clearance 0.04 of Stroke Fig. 24

measured in a quart or pint measure and the number of cubic inches found directly. A gallon contains 231 cubic inches, a quart 57.75, and a pint 28.875 cubic inches.

The volume of the clearance will rarely be the same at the two ends of the cylinder, therefore the number of cubic

Digitized by VjOOQlC

inches in the clearance at each end must be divided by the net area of the piston at its own end: that is, the number of cubic inches in the clearance at the end nearest the crank must be divided by the number of square inches in the cross-section of the cylinder, less the number of square inches in the cross-section of the piston-rod; and the number of cubic inches in the clearance at the end farthest from the crank must be divided by the number of square inches in the cross-section of the cylinder. The quotient in each case will be the length of clearance at the respective ends of the cylinder, expressed in inches. In this instance (Fig. 24) it is found to be 0.16 of an inch.

It is convenient to have the length of the clearance expressed as a fraction of the piston displacement or stroke of the piston. To obtain this fraction, divide the number of cubic inches in volume of clearance by the number of cubic inches in the volume swept through by the piston at each end separately, taking care to allow for the volume occupied at one end by the piston-rod, and the quotient will be the decimal fraction that the clearance space is of the volume swept through by the piston.

Fig. 24 illustrates a good method for locating points in the hyperbola through which the curve may be drawn.

First, draw the zero line V, at the proper distance, viz., 14^ pounds by the scale, below and parallel with the atmospheric line; next, draw the clearance line O, as computed, 0.16 of an inch from the end of the diagram; next, locate the point of cutoff X, and draw the perpendicular line numbered 3 through it; next, divide the space between this line and the clearance line into three equal parts; then, taking one of these parts for a measure, point off, on the vacuum line, equal spaces toward the left hand until one or more falls beyond the end of the diagram as shown, and erect perpendicular lines from each point. These lines are called ordinates and numbered consecutively 1, 2, 3, 4, etc.,

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.