SCRUBBING AIR

A STATE-OF-THE-ART STUDY IS PRESENTED OF AIR POLLUTION CONTROL METHODS. AIR POLLUTION INVOLVES CONTAMINATION OF THE ATMOSPHERE BY PARTICULATES OR GASES OR BOTH. PARTICULATES INCLUDE LIQUID DROPLETS AS WELL SOLID PARTICLES. GASES FOR THIS DISCUSSION INCLUDES ODORS. THESE TWO TYPES OF POLLUTANTS GENERALLY UTILIZE TWO DISTINCTLY DIFFERENT TYPES OF CONTROL EQUIPMENT. THE SIMPLEST AND LEAST COSTLY FORM OF PARTICULATE COLLECTOR IS THE DRY INERTIAL OR MECHANICAL TYPE. THE CYCLONE IS THE MOST COMMON AND HIGHLY DEVELOPED FORM OF MECHANICAL PARTICULATE COLLECTOR. LESS SIMPLE AND SOMEWHAT MORE COSTLY ARE THE WET, INERTIAL DEVICES CALLED SCRUBBERS. SCRUBBERS CAN COLLECT DROPLETS AS WELL AS PARTICULATES. THEY ALL OPERATE ON THE PRINCIPLE OF IMPACTION OF PARTICLES ON WET SURFACES OR ON INDIVIDUAL DROPLETS OF SCRUBBING LIQUID, WITH DROPLETS ALMOST INVARIABLY USED FOR ACHIEVING HIGH EFFICIENCIES WITH FINE PARTICLES. AN OUTSTANDING CHARACTERISTIC IS AN INHERENT HIGH COLLECTION EFFICIENCY, REGARDLESS OF PARTICLE SIZE. THE ELECTROSTATIC PRECIPITATOR APPLIES ITS CLEANING ACTION ONLY TO THE PARTICULATES (DROPLETS OR SOLIDS) AND THE POWER INPUT REQUIREMENT IS LOW. THE PRECIPITATOR IS SUITED FOR VERY LARGE GAS VOLUMES AND CAN COLLECT PARTICLES DOWN TO SUB-MICRON SIZE WITH HIGH EFFICIENCY. THE BASIC ELEMENTS OF AN ELECTROSTATIC PRECIPITATOR ARE A CURRENT SOURCE OF UNIDIRECTIONAL HIGH VOLTAGE, A CORONA OR DISCHARGE ELECTRODE, A PASSIVE OR COLLECTING ELECTRODE, AND A RECEPTACLE INTO WHICH COLLECTED MATERIAL CAN DRAIN OR FALL. ABSORPTION IS A PROCESS WIDELY USED FOR COLLECTION OF VAPORS THAT OTHERWISE WOULD ESCAPE OR BE DISCHARGED TO THE ATMOSPHERE PARTICULARLY SOLIDS THAT CAN RECOVERED AND REUSED ACTIVATED CARBON IS A COMMON ADSORBANT. FLAME COMBUSTION OR INCINERATION CAN REMOVE COMBUSTIBLE AERESOLS AND GASES, ELIMINATING TOXIC OR ODOROUS COMPOUNDS AND ELIMINATING THE DANGER OF EXPLOSION, WITH EFFICIENCIES AS HIGH AS 90% OR MORE. A TALL CHIMNEY IS AN AIR POLLUTION CONTROL DEVICE BECAUSE SOME POLLUTANTS WHEN RELEASED IN THE AIR ARE ACTED UPON BY NATURAL PROCESSES THAT CAN CONVERT RELATIVELY HARMLESS SUBSTANCES.

  • Supplemental Notes:
    • No 95, P 18-21, 24-27, 7 FIG
  • Authors:
    • Walker, A B
    • Frisch, N W
  • Publication Date: 1969-11

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Filing Info

  • Accession Number: 00219394
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Sep 21 1970 12:00AM