Document dQ6DJeEdz4ggNn0BXEoONZMbe

f `*i A To: From: W. J. Stueben Re: Sound Level Measurements Nitric Acid Plant _____ _ T. J. Regan R. B. Chandler R. L. Duggan C. E. Good Sound levels were measured in the Nitric Acid Plant on 6, 7 and 23 March 1979 to determine the loudness of the 40 lb. steam vent when operating. Measurements were also taken on these same days with the vent off to determine background noise. Instantaneous readings with the vent off averaged 93 dB on the A scale. The A scale reading with the vent on was 105.2 dB. A dosimeter left in the plant for four hours with the vent off registered an exposure of 95 dB (A), indicating that the cumulative noise exposure is greater than the 93 dB (A). No dosimeter readings were made for the period the vent was on but would probably indicate slightly higher cumulative exposure than the 105.2 dB average. The difference in sound levels, 12.2 dB (upwind), shows that the level measured was the noise from the vent and the background noise was not significant (ANSI Std. 1.2 - 1962). The octave band analysis indicates that the predominant frequencies are at the most sensitive part of the hearing range. Recommendation: Provide a muffler for the steam vent to reduce the noise level with the vent on to 70 dB (A) at 30 feet. The following companies can provide a muffler for the appropriate noise level reduction: 1) IDE Processes Corporation - Noise Control Division 23-26 Broadway Astoria, New York 11106 (212-278-6696) 2) The Aeroacoustic Corporation 4876 Victor Street Jacksonville, Florida (904-731-3577) AP00032779 B. A. Gebbia -2- 27 March 1979 3) T. F. Hudgins & Associates, Inc. * 4405 Director's Row P.O. Box 10946 Houston, Texas (713-682-3651) Sales Engineer - David J. Montegut * They are sales agents for VANEC, a leader in^noise control and your recommended primary contact. If an engineering request is written, X can assist the engineer assigned when dealing with any of these companies. If not, I can make the contacts for you. Flow information in terms of cubic feet per minute should be available. W. J. Stueben WJSrjsf Attachment (Noise Level Data Sheet) AP00032780 t DATE 3/6, 3/7, 3/23/79 BUILDING Nitric Acid Plant_________ SOUND MEASURING EQUIPMENT ^_ General Radio Model 1982 Sound Level Analyzer SAMPLE READING LOCATION 40 lb. Vent downwind 30' (Not on) 40 lb. Vent upwind 401 (Not on) NOISE LEVEL DATA SHEET TIME data er W. J. Stueben EQUIPMENT CONOI TIONS 40 lb. vent (Operating vs. background) Wind 6-8 mph S WEIGHTEO SCALE CENTER FREQUENCY OCTAVE LEVELS - HERTZ As Indicated SOUND PRESSURE LEVEL - DECIBELS r* 0.0002 Microbar. A* s c ALL PASS 31.5 63 125 2SQ .500 1000 2000 93 100 92 90 85 81 84 86 84.0 91 98 JO.5 90 86 79 80 80 80.5 4000 85 83 8000 16000 82,1 77 83.5 81.5 40 lb. Vent downwind^) 30" (ON) 05.2 czr~ 40 lb. Vent upwind^ 40* (ON) 99.6 At ground level near flow meter (ON 100. ) L07.5 99.7 90.9 87.7 85,4 8,5,3 90,$ 95_^_ 106.4 IQlJ 97.9 L04.1 91.0 89.1 88.1 82.4 82.9 85.1 89.6 97.0 89.4 87.4 ADDITIONAL INFORMATION 10* in front of an intake No. 1 Fianc. ^No sKnjficant difference with vent on or off) 105 106 91.5 94' 91 87.5 98 99.5 98.5 100 96.5 89 AP0003278 OSHA REGULATIONS Parmiolbla Hrf/dar Mtxlimm Delb*ll without Protection > 115 115 no 103 102 100 . 97 95 92 90 < 90 dBA" dBA dBA dBA dBA dBA dBA dBA dBA dBA dBA None % 1 1% 2 3 4 6 8 Any (1) Flow ^ 70% REMARKS (2) Highest reading was 106. Sound levels are averages of 3 readings taken onthe indicated dates. Exposure for a four hour period when the vent was off was 95 dBA. All measurements were taken using a windscreen. The sound level meter wa? calibrated before each measurement.