Masters Theses

Keywords and Phrases

Exhaust muffler design

Abstract

"One-third octave spectrum analyses of the exhaust noise produced by a medium sized pneumatic rock drill were obtained during free recriprocation to determine the most troublesome bands of noise. Noise reduction techniques were then used to design exhaust mufflers which would reduce the level of the exhaust noise to an acceptable level with a minimum increase in back pressure. The prototype mufflers evaluated included an expansion chamber, a resonator, and various modified expansion chambers. One of the modified expansion chambers tested provided very good attenuation reducing the exhaust noise from 113 dBA to 87 dBA at the operator's ear position. It caused only a slight increase in the back pressure and no detrimental effect on drill performance. The resonator muffler did not provide acceptable attenuation of the exhaust noise. Muffler development progressed under the assumption that icing would not be a problem. However, the icing characteristics of the final prototype muffler were studied and a possible method to prevent icing is suggested"--Abstract, page ii.

Advisor(s)

Gatley, William S.

Committee Member(s)

Koval, Leslie Robert
Spokes, Ernest M., 1916-1995

Department(s)

Mechanical and Aerospace Engineering

Degree Name

M.S. in Mechanical Engineering

Sponsor(s)

United States. Bureau of Mines

Publisher

University of Missouri--Rolla

Publication Date

1972

Pagination

xii, 159 pages

Rights

© 1972 Morton Gary Barth, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Rock-drills -- Design
Pneumatic tools -- Noise
Rock-drills
Pneumatic machinery

Thesis Number

T 2712

Print OCLC #

6032700

Electronic OCLC #

881829086

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