An Investigation of Explosion-Proof Motors Page: 11
56 p. : ill.View a full description of this report.
- Highlighting
- Highlighting On/Off
- Color:
- Adjust Image
- Rotate Left
- Rotate Right
- Brightness, Contrast, etc. (Experimental)
- Cropping Tool
- Download Sizes
- Preview all sizes/dimensions or...
- Download Thumbnail
- Download Small
- Download Medium
- Download Large
- High Resolution Files
- IIIF Image JSON
- IIIF Image URL
- Accessibility
- View Extracted Text
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
PROCEDURE OF INVESTIGATION.
GAS AND EQUIPMENT USED.
GAS.
The natural gas supplied to the city of Pittsburgh was used in all
tests. Its composition a is approximately 82 per cent methane or
marsh gas, 16.4 per cent ethane, 1.5 per cent nitrogen, and a trace of
carbon dioxide. The term "gas" wherever used in this report refers
to this natural gas.
The most explosive mixture b of such gas and air is one combined in
the proportion of 8.6 :91.4. This mixture also burns most rapidly
and evolves the greatest amount of heat.
In this report a mixture containing more than 8.6 per cent of gas is
termed an "overgassed" mixture, and a mixture containing less
than 8.6 per cent of gas is termed an "undergassed" mixture.
TESTING APPARATUS.
The apparatus used in the tests included the following:
(1) A gas-tight gallery or inclosure in which the motor to be
tested was installed. (P1. I.)
(2) A circulating fan for mixing the gas and air within the gallery.
(3) A system of piping connecting the gallery and circulating fan.
(4) A device for determining the percentage of gas in the mixture.
(P1. II and fig. 1.)
(5) A pressure indicator attached to the motor casing to record
the pressure developed therein by the explosion.
(6) Spark plugs mounted within the motor casing and operated
by an induction coil.
(7) A system of piping and valves connecting the motor casing
with the fan intake for the purpose of filling the motor casing with
the gaseous mixture.
TESTING GALLERY.
The gallery in which the motor was installed for the tests was a
boiler-plate cylinder, 10 feet in diameter and 30 feet in length, set
horizontally upon a concrete foundation. Seven feet from each
end the cylinder was stopped off with diaphragms of heavy manila
paper reinforced with cheese cloth and painted with one coat of
white lead and oil to make them gas-tight. A manhole cut in the
side of the gallery between the diaphragms made entrance possible
without the disturbing of the paper stoppings. Observation windows
of heavy plate glass were placed at intervals along the sides of the
gallery. Plate I shows the general appearance of the gallery and
testing house. Electrical connections were brought through bushings
in the side of the gallery to a slate terminal board.
a Burrell, G. A., The natural gas used at Pittsburgh: Bull. 15, Bureau of Mines, 1912, p. 66.
b Idem, p. 77.11
Upcoming Pages
Here’s what’s next.
Search Inside
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
Clark, H. H. An Investigation of Explosion-Proof Motors, report, 1912; Washington D.C.. (https://digital.library.unt.edu/ark:/67531/metadc12261/m1/13/?q=%22United+States.+Bureau+of+Mines.%22: accessed June 14, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.