Document NEaQ96woG7zkaR4B5DaDn0Lz8

166 CHAPTER 12 1965 Guide And Data Book'' Table 3 Odor Index for Type of Space* - iocaRoas A contain 0* towed amount of odor and D A* Ugtmd. B e&J C npnstnl hitli in bafwMA. Many of the douificatiom or* rafter gonaral to if wot meottary to pid a typkai or awagi nndrfioo. Tbo odor index for a tpndffe tdvatioa coold rory tomowbaf from (hot givea in fte table if special dnumdaxt apply. to typical earns, atm pound of 50-mfaota ocfiratod coconwf dtoB dtoreoaf wBJ purify &e fallowing cubic foot of space for ono nor. 2000 of hvel A, 800 of fcvef 8, 300 of hvel C, and 100 at level 0. C--Adhesive manufacturing plants * *. C--Air conditioning systems C--Aircraft B--Airline terminals ' B--Dining rooms. B--Display parlors C--Distilleries ' C--Doctore' offices ' 1 B--Drafting rooms : D--Air raid shelters B--Amusement places D--ATMTM*! rooms A--Apartments C--Apple storage - B---Dressing rooms C---Drug stores ' C--`Dry cleaning plants * B--Educational institutions B--Electrical installations B--Art studios C--Athletic clubs D--Atomic processes B--Auditoriums C--Automobiles B--Banka C--Bank counting rooms C--Bank safe deposit , departments D--Bank vaults C--Elevators D--Embalming rooms C--Engine rooms B--Equipment 'rooms C--Examination rooms: D--Exhaust hoods C--Factories B---Federal offices C---Fermentation plants D--Fertilizer plants C--Banquet rooms C--Barber shops C--Ban C--Basements B--Bathrooms . C--Fish markets' .C--Five and ten cent stores C---Food processing A--Forced air furnaces' C--Fruit storages * C--Beauty shops A--Bedrooms ' B--Binderies D--Biological processes D--Bombshelters. C--Funeral homes C--Game rooms D--Garbage disposal plants | A--Gravity return furnaces B--Greenhouses B--Book stacks C--Breweries C--Buses B--Bus terminals B--Cafeterias ' .. B--Grocery stores C--Grills A--Homes C--Hospital rooms C--Hospitals * t C--Canneries C--Central air conditioning systems D--Chemical laboratories D--Chemical plants' B--Hotels " B--Hotel rooms C--Incinerators C--Individual cubicles C--Industrial kitchens D--Chemical storage D--Chlorine manufacture A--Churches C--Clinics C--Club houses - - - B--Industrial offices B--Institutions B--Instrument rooms B--Jewelry stores C--Kitchens D--Coating processes' * * C--Cocktail lounges * C--Cold storage plants............ D--Collective protection shelten D--Kitchen' exhausts D--Laboratories....... ! C--Laundries - ' D--Leather processing B--Libraries , B--Commence! establish ments C--Conference rooms B--Corridors C--Creameries 1 D--linoleum plants' C--live poultry rooms' A--Living rooms B--Lobbies. C--Locker rooms Gr-Crowded rooms C--Dairies O^Darkrooms " D--Decalcomania production` B--Department stores C--Dentists' offices B--Lounges C--Lunch counters C--Lunch rooms B--Maintenance departments C---Manufacturing plants C--Mausoleums D--Meat packing plants. C--Meat markets * C--Meat storage B--Metal industries C--Military equipment; ' B--Restaurants C--Restaurant kitchens A--Retail shops D--Rubber plants B--Rumpus rooms -J B--Military installations C--Mixed cold storage- C--Morgues B--Motels - C--Motion picture studios B--Sales rooms B--Sample rooms C--Schools C--Service departments C--Sewage disposal plants B--Municipal offices - * B--Museums C--Night clubs - D--Nuclear processes .. B--Nurseries D--Sewer vents C--Show cases C--Sick rooms ` B--Silverware manufacture C--Soap manufacture B--Offices C--Office buildingB C--Officers' clubs- * D--Oilcloth production . C--Operating rooms B--Soda fountains C--Specialty shops B--State institutions B--Steamships B--Stock rooms. D--Paint departments C--Paint plants ... : C--Penal institutions C--Pet shops C--Pharmaceutical plants B--Storage spaces B--Stores C--Studios. , , . B--Stuffy rooms B--Super markets C--Photo dark rooms ... C--Surgical rooms C--Photographic industry , B--Switchboard, rooms C--Photographic studios .C--Tanneries - B--Planes D--Tar processing - C--Plastics manufacturing C--Taverns C--Plating shops . , D--Pollution control C--Poultry processing'1 C--Poultry sales rooms C--Prescription departments C--Telephone booths C--Telephone exchanges - C--Television studios C--Test cubicles B--Theaters C--Printing plants . C--Theater lobbies B--Private offices C--Theater lounges ' C--Processing laboratories- > B--Ticket booths C--Processing rooms C-r-Toilets .. D--Projection booths B--Trains C--Public assembly rooms * B---Public buildings , C--Public toilets ^. D--Pulp and paper plants - C--Radio studios . - B--Train reservation offices' C--Undertakers * B--Unit fur coolers C--Untidy rooms,.hospital ,C--Unventilated spaces C--Railway cars ` B--Railway stations B--Reading rooms B--Reception rooms C--Recovery room;1 hospital1- D--Varnish manufacture "' C--Vegetable storage D--Vent systems '; C--Vestibules C--Veterinary hospitals C--Recreation halls . , ....... B--Waiting rooms. C--Recreation rooms ' G^-Wards, hospital C--Refineries B--Warehouses C--Refrigerated show cases D--Rendering plants _ j D--Waste treatment plants B--Window ventilators . C--Refrigerators C--Research-buildings' C--Reservation offices A--Residences D--Resin manufacturing. B--Restrooms B--Wood working plants C--Work rooms C--X-Ray darkrooms B--Yachts Cr-Youth clubs ' C--Zoological gardens ' Odors'" Although different adsorbents may be used, 50-min coconut-shell charcoal has been used as & standard. (The term 50-min refers to tire length of time required for chioropicrin vapor to break through in a particular laboratory test used by the V. S. Army Chemical Corps and the Bureau of Standards to rate gas-mask charcoals.) The principle behind the use of charcoal adsorption', in ventilating systems is that all or part of the recirculated air can be rendered free of odors. Air that has been completely purifiod by adsorption is capable of diluting odorous.air and may. be substituted for air brought in. from outdoors. As can be seen in.Fig. 2, most of the outdoor air in ventilating sys tems is required for odor.control. The small percentage rennired to supply oxygen and remove excess carbon dioxide is ueu sfiovw. When the activated charcoal in adsorber cells has become loaded with odor-producing vapors, the cells can be recharged with virgin activated or reactivated charcoal. The spent char coal can be discarded or. returned to the factory for reactiva tion. In some cases, it is possible to reactivate or regenerate the charcoal in place. If the charcoal has been loaded with vapor caused by the evaporation of low-boiling solvents, as in many process applications, it may be possible to recover the solvents for reuse or resale with the same equipment that is used to purify, and reoover, the recirculated air. The main advantage in using a sorption process ;for odor control, rather than outdoor air, is that it is often possible to save on heating and cooling capacity and operating costs. In addition, it is useful where the outside air is polluted or where it is remote, he., where it would be necessary to use consider able ductwork in order to bring outdoor air .into the odorcontaminated space. Suitable impregnation of an active hydrophyllic substrate provides chemical destruction of the adsorbed odor mole- 167 culeA8 Potassium permanganate on activated aluminum has been used for the removal of some reactive odors. As with any adsorptive process, the odorous species must contact the solid-substrate before adsorption can take place. Hence, the air stream must pass through the bed of absorbent material at a velocity which will provider maximum of contact time. The oxidation-reduction reactions which occur on the surface of the porous solid substrate are dependent upon the coaction of the chemical oxidant and its' activated substrate. Washing and Scrubbing: - ----------- - Where odorous vapors are soluble or emulsifiable in a liquid, with or without chemical reaction, odor removal by liquid absorbents may be suitable.8 Absorbents may be water, modified' water solutions, or oils! Odors as vapors may be removed by spray washers, packed scrubbers, and wet cooling coil&i but not by the usual dry filters, unless the filter is made of special adsorbent materials. The effectiveness of all sorbent processes depends on two mechanisms: 1. Contacting the air containing the odor with the sorbent materials. The efficiency is directly related to the time in contact or inversely related to the velocity. 2. Maintaining the sorbent materials in the sorbing' condition. Adsorbent solids must be reactivated or replaced ana absorbent liquids must be regenerated or replaced. Some of the equipment designed to contact the air with liquids include spray washers, wetted-wall columns, bubble cap columns, and venturi scrubbers.*4-8 A spray tower (Fig. 4) is one type of absorber used to re move objectionable aerosols from air streams. Atomization of liquid absorbent, and uniform distribution of air to provide mTimnm contact between absorbent and gas are necessary CLEAN Ain OUTLET CLEAN AIR OUTLET