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Clean Air Solutions for Dust & Mist Processes

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CAAA: Clean Air Act Amendments of 1990.
Title I: Non-attainment: Ambient Air Quality
Title II: Motor Vehicles
Title III: Hazardous Air Pollutants
Title IV: Acid Rain
Title V: Permits
Title VI: Stratospheric Ozone
Title VII: Enforcement
Title VIII: Miscellaneous

CAKING: Material crusted on a bag that cannot be removed by the cleaning mechanism. Frequently caused by the dust on the bags getting wet.

CALENDARED FINISH: An available smooth finish for felt bags. Felt is drawn between two hot oil-filled rolls, where heat and pressure press down “hairs” on the felt, imparting a smooth finish that improves dust release.

CALENDARING: The application of either hot or cold pressure to smooth or polish a fabric, thereby reducing the thickness of the cloth by spreading the warp and filling yarns into a ribbon shape.

CAN VELOCITY: As related to baghouses, the gas velocity within the collector. Dividing the gas volume by the cross sectional area of the collector determines “can velocity.” Also see interstitial velocity.

CAPACITOR START MOTOR: Type of single-phase induction motor with a capacitor connected in series with the starting winding. High–starting and breakdown torque, medium starting current. Used in hard-starting applications; compressors, pumps, etc.

CAPTURE VELOCITY: The air velocity at any point in front of a hood or at a hood opening necessary to overcome opposing air currents and to capture the contaminated air at that point by causing it to flow into the hood.

CARBON MONOXIDE: A colorless, odorless gas that is toxic because of its tendency to reduce the oxygen-carrying characteristic of blood.

CARRYING VELOCITY: The gas velocity that is necessary to keep contaminants airborne. Usually between 2,000 to 5,000 ft/min in duct work, depending on the nature of the contaminant.

CARTRIDGE: See pleated filter elements.

CARTRIDGE FILTER: An air pollution control device that traps gas-borne particulates by forcing the gas through filter element cartridges. The cartridges are typically made with pleated non-woven media. Recently, 100% spun bond synthetic media filters have been developed.

CHEMICAL ABSTRACTS SERVICE (CAS): Registry Number is a numeric designation assigned by the American Chemical Society’s Chemical Abstracts Service, which uniquely identifies a specific chemical compound.

CELLPLATE: See tubesheet.

CELLULOSE: The chief part of fibrous products that are used to make the filter media for many cartridge filters. Sometimes referred to as “paper” media.

CENTIFUGAL COLLECTOR: Any of several mechanical systems using centrifugal force to remove particulate from a gas stream.

CELSIUS: A thermometric scale in which water boils at 100° and freezes at 0°, same as centigrade. °C = 0.5556 x (°F – 32°) 5/9 = 0.5556

CFM: Volumetric flow rate expressed as Cubic Feet (of any gaseous mixture) per Minute. See gas flow.

CHAMBER SILENCER: Insulated box or housing placed around a fan and motor to attenuate sound.

CLOTH: In general a pliant fabric; woven, knitted, felted or otherwise formed of any textile fiber, wire or other suitable material. Usually understood to mean a woven felted or textile fabric.

CLOTH WEIGHT: Usually expressed in ounces per square yard or ounces per square foot. However, cotton sateen is often specified as a certain number of linear yards per pound in a 54” width.

COKE OVEN: An industrial process which converts coal into coke, which is one of the basic materials used in blast furnaces for the conversion of iron ore into iron.

COLD SPOT: On an insulated baghouse, a point where metal goes through insulation, creating an uninsulated area where heat dissipates rapidly.

COLLECTING EFFICIENCY: The ability of a dust collector to remove particulate from the exhaust gas. The ratios of particles entering the collection device vs. particles leaving is expressed in percent. inlet loading – outlet loading x 100 inlet loading

COLLECTION: Removal of contaminants from an airstream. Note, collection is distinct from “capture” in that both must be accomplished if an air cleaning system is to function properly.

COLLECTION CELL: Set of alternately charged and grounded plates in a SMOGHOG electrostatic precipitator where particle collection occurs.

COLLECTOR: Used interchangeably with “baghouse,” “cartridge filter” or mechanical collector, as in “cyclone.”

COMBUSTIBLE/EXPLOSIVE DUST: Finely divided materials that can cause or support combustion, such as aluminum, flour, corn starch, etc.

COMBUSTION: The production of heat and light energy through a chemical process; usually oxidation. One of the three basic contributing processes of air pollution, the others being attrition and vaporization.

COMBUSTION AIR: Amount of air necessary to burn available fuel.

COMBUSTION PRODUCTS: (1) Primarily gaseous matter such as carbon oxides, nitrogen, oxygen and water vapor, resulting from the combustion of fossil fuels. (2) In the context of emission control, the gaseous products resulting from burning any kind of material containing carbon in a free state or combined state. Also referred to as “combustion contaminants.”

COMPRESSIBILITY: A factor used by fan manufacturers to correct performance rating in higher pressure ranges to account for the fact that air is a compressible gas that does not follow the perfect gas laws.

COMPRESSION: A phenomenon related to positive pressure. When air is forced into a system, it is compressed and becomes more dense. Depending on the volume or weight of air required down stream in the positive pressure portion of the system, the volume of air at the inlet of a fan may have to be adjusted by the ratio of absolute pressure at the entrance of the fan versus the design requirements in the system.

CONCENTRATION: The amount of dust in gas. Usually expressed in terms of grains per ft3, lbs per 1,000 lbs of gas, parts per million or milligrams per cubic meter.

CONDENSIBLE PARTICULATE: Hot gases or vapors that condense when cooled. UAS uses the term to define the contaminants in a hot process exhaust that are gases when generated and can be cooled to form aerosol particles.

CONTAMINANT: Unwanted airborne substance that can be a health hazard or can create visibility problems within the industrial environment.

CONTROL: The reduction of pollutant emissions by addition of air cleaning equipment designed to collect all or part of the contaminant generated by a process.

CORROSIVE DUST: Particles that can cause degradation by chemical action to surfaces they contact, such as salt, soda ash, detergents, etc.

CONVERSION FACTORS: See Section 8.

CONVEYING VELOCITY: The air velocity required in a duct system to maintain entrainment of a specific material.

CORROSION: The deterioration of material by chemical or electrochemical reaction resulting from exposure to weathering, moisture, chemical or other agents in the environment in which it is placed.

CRST (Cellulosic Fibers, Resin Impregnated, Silicone Treated): A type of filter media used in high-quality cartridges. The treatments enhance filter life and moisture resistance.

CSA (Canadian Standards Association): Sets safety standards for motors and other electrical equipment used in Canada.

CTG (CONTROL TECHNIQUES GUIDELINE): Guidance documents issued by EPA which define Reasonably Available Control Technology (RACT) to be applied to existing facilities that emit certain threshold quantities of air pollutants; they contain information both on the economic and technological feasibility of available techniques.

CURVE, FAN PERFORMANCE: A graphic representation of static or total pressure and fan BHP requirements over an airflow volume range at a stated inlet density and fan speed.

CURVE, SYSTEM: A graphic representation of the pressure versus flow characteristics of a given system and density.

CYCLONE COLLECTOR: A kind of centrifugal collector equipment.