Smoke, removal

The predominant cellulose ester fiber is cellulose acetate, a partially acetylated cellulose, also called acetate or secondary acetate. It is widely used in textiles because of its attractive economics, bright color, styling versatiUty, and other favorable aesthetic properties. However, its largest commercial appHcation is as the fibrous material in cigarette filters, where its smoke removal properties and contribution to taste make it the standard for the cigarette industry. Cellulose triacetate fiber, also known as primary cellulose acetate, is an almost completely acetylated cellulose. Although it has fiber properties that are different, and in many ways better than cellulose acetate, it is of lower commercial significance primarily because of environmental considerations in fiber preparation. 

Elevators, dumbwaiters, and escalators are a challenge to managing the migration of air from floor to floor. These vertical transportation devices should be placed in lobbies on each floor with automatically closing doors between the lobbies and the corridors to isolate the shafts from the rest of the floor. These are also requirements in many codes for fire and smoke control. Similarly, the ability to seal multistory atriums from the rest of the floors is essential, and codes often require them to be provided with smoke removal fans. 

Means of egress criteria may also rely upon the presence of other building features in the chemical warehouse. Examples include automatic sprinkler systems, fire detection/warning systems (optical flamesensing, smoke, heat, etc.) and smoke removal systems. In certain situations, these systems may permit less restrictive arrangements of the means of egress components. 

Powered ventilation systems in chemical warehouses are typically used for some flammable gas and liquid storage areas (see Gas and Vapor Control, Section 6.6). Heating and ventilation systems and powered roof exhaust systems can be arranged to shut down automatically upon receipt of a fire alarm signal so as not to interfere with sprinkler system operations due to airflow. Furthermore, these systems can also be arranged for manual starting and full exhaust by the fire department for smoke removal during search and rescue operations. 

Cellulose acetate and triacetate fibers have survived in the marketplace because they have certain unusual properties that demonstrate significant advantages over other polymerie materials. Cellulose acetate and triacetate textile fibers are luxurious. Fabrics made from them have an excellent hand, dye to brilliant, attractive shades, and are soft and comfortable. Regarding cellulose acetate and triacetate plastics and films, no other polymers can match the sparkling clarity possessed by these. For cigarette-smoke filtration, cellulose acetate offers a unique balance of properties including smoke removal efficiency and contribution to taste that makes it the standard of the industry. 

Tow properties are influenced by the shape of the filament cross section, dpf, and total denier, and the crimp imparted to the tow. The tow properties in turn control the properties of the cigarette filter. Important filter properties of weight, firmness, pressure drop, smoke-removal efficiency and cost are controlled by the fiber and tow properties [15,85,86]. 

Finally, the choice of a liquid dielectric is always the fruit of compromise between technical and economic imperatives and the safety of lives and property. It must therefore be remembered that appropriate regulations for installation and operation, oil pits, fire walls, fireproofing, smoke removal system, absence of overloading, electrical protection, detection of latent defects) can go a long way towards remedying the disadvantages inherent in an imperfect solution. 

Provides smoke removal capability for the main control room and control support area... 

Since fungi spreads through air born spores, is there a more efficient way to attack these spores With the presence of electrostatic precipitators and smoke removers, would these be effective in abstracting the spores and destroying them How many and what size would be needed for an average library Is it a waste of time to try to remove them from the air ... 

The beaker and thermometer should be removed from the metal bath before the latter solidifies. Metal baths have the advantage that they do not smoke or catch fire they are, however, solid at the ordinary temperature and are usually too expensive for general use. 

Aromatic and Nonaromatic Hydrocarbon Separation. Aromatics are partially removed from kerosines and jet fuels to improve smoke point and burning characteristics. This removal is commonly accompHshed by hydroprocessing, but can also be achieved by Hquid-Hquid extraction with solvents, such as furfural, or by adsorptive separation. Table 7 shows the results of a simulated moving-bed pilot-plant test using siHca gel adsorbent and feedstock components mainly in the C q—range. The extent of extraction does not vary gready for each of the various species of aromatics present. SiHca gel tends to extract all aromatics from nonaromatics (89). 

Uses. The principal use of magnesium hydroxide is in the pulp (qv) and paper (qv) industries (52). The main captive use is in the production of magnesium oxide, chloride, and sulfate. Other uses include ceramics, chemicals, pharmaceuticals, plastics, flame retardants/smoke suppressants, and the expanding environmental markets for wastewater treatment and SO removal from waste gases (87). 

Kerosene is beheved to be composed chiefly of hydrocarbons containing twelve to fifteen carbon atoms per molecule. Low proportions of aromatic and unsaturated hydrocarbons are desirable to maintain the lowest possible level of smoke during burning. Although some aromatics may occur within the boiling range assigned to kerosene, excessive amounts can be removed by extraction. 

Phthalocyanines are excellent lubricants at temperatures of 149—343°C (191). Combinations with other lubricants, like grease, molybdenum, or tungsten sulfides, have found appHcations in the automotive industry or professional drilling equipment (192—195). Further uses include indicators for iron(Il), molybdenum(V), and uranium(IV) (196) or redox reactions (197), medical appHcations like hemoglobin replacements (198) or sterilisation indicators (199), or uses like in gas filters for the removal of nitrogen oxides from cigarette smoke (200). 

Techniques for handling sodium in commercial-scale appHcations have improved (5,23,98,101,102). Contamination by sodium oxide is kept at a minimum by completely welded constmction and inert gas-pressured transfers. Residual oxide is removed by cold traps or micrometallic filters. Special mechanical pumps or leak-free electromagnetic pumps and meters work well with clean Hquid sodium. Corrosion of stainless or carbon steel equipment is minimi2ed by keeping the oxide content low. The 8-h TWA PEL and ceiling TLV for sodium or sodium oxide or hydroxide smoke exposure is 2 mg/m. There is no defined AID for pure sodium, as even the smallest quantity ingested could potentially cause fatal injury. 

Inhalation. The threshold limit value of HCN is 4.7 ppm. This is defined as the maximum average safe exposure limit for a 15-min period by the Occupational Safety and Health Administration. Exposure to 20 ppm of HCN in air causes slight warning symptoms after several hours 50 ppm causes disturbances within an hour 100 ppm is dangerous for exposures of 30 to 60 min and 300 ppm can be rapidly fatal unless prompt, effective first aid is adininistered. There is always a small concentration of cyanide (0.02 to 0.04 mg/L) in the blood, and the body has a mechanism for continuous removal of small amounts, such as from smoking, by converting it to thiocyanate, which is discharged in the urine. 

Abrasive. Dentifrices have the unique ability to remove extrinsic tooth stains, which are caused by agents such as berries, tea, smoking, antibiotics, and certain bacteria as they attach to the dental pellicle. These stains can be removed only by abrasive cleaning a toothbmsh alone is not adequately effective. It has been shown that only 4% of a test population were able to maintain thein teeth in an acceptably stain-free state without an abrasive and that 18% of the population were "heavy" stainers (2). However, colored materials found in dental plaque are removable without abrasives. 

One processing problem is presented by the roasting of coffee. This releases smoke, odor, and particulate matter. The particulate matter, primarily dusty and chaff, can be removed with a cyclone. The smoke and... 

Remove or reduce the source Prohibit smoking indoors or limit smoking to areas from which air is exhausted, not recirculated (NIOSH regards smoking areas as an interim solution). Relocate contaminant-producing equipment to an unoccupied, better ventilated, or exhaust-only ventilated space. Select products which produce fewer or less potent contaminants while maintaining adequate safety and efficiency. Modify other occupant activities. 

Application of contaminant removal effectiveness indices is relatively simple for scenarios with one or a few dominant contaminants being released. That is often the case in industrial mails. Where there are many polluting substances to consider the contaminant removal efficiency should ideally be evaluated for each one. Consequently, applications for regular indoor climate— for example, in a restaurant—are limited, except when addressing specific pollutants like smoking and ctxrking hunes. 

---