Donaldson Industrial Air Filtration Dictionaryi ii iii Abrasiveness: The dust characteristic that will tend to rub away, or abrade, the filter media or collector. Examples of abrasive dusts include sand, rock, and shot blast. acfm: Actual cubic feet of air flowing past a fixed location in 1 minute. Accessories: Ancillary components to a collection system. Examples include fans, rotary airlocks (valves), afterfilters, electricals/controls, broken bag detectors, and bin level indicators. Acoustic Diffuser (AD): A silencer. Depending on the dust collector, it may be either a chamber type silencer with acoustical lining covering the entire fan assembly or an add-on silencer panel. Acrylic: An optional bag filter material of construction. Acrylic offers a good combination of abrasion resistance and resistance to heat degradation under both wet and dry conditions. An outstanding characteristic is the ability of acrylics to withstand hot acid atmospheres, making this fiber a good choice in the filtration of exhaust gases. Acrylic fibers are used for dust collection in the manufacturing of ferrous and non-ferrous metals, carbon black, cement, and lime fertilizers. Other applications include the drying of raw flour, sand, coal, mining, and ore dressing. AerBENCH™: Obsolete Aercology remote downdraft bench. AerBooth: Obsolete Aercology self-contained workstation incorporating dust control with optional noise control and lighting. Aerosol: Small particles, solid or liquid, suspended in air. The particle size may vary from 100 microns down to 0.01 microns or less, such as dust, fog, or smoke. AerTABLE: Obsolete Aercology downdraft bench with filtration system. AerTite Filter Clamping System: A bottom lift, easy, tooless filter compression and clamping system developed by Aercology. Used in the MH HEPA module (MDV units), the CFP cartridge, and obsolete WA cartridge units. AEX™ Plus: Obsolete Aercology flex arm. Agglomerativeness: The dust characteristic that will tend to gather the dust into a ball, mass, or cluster. Examples of agglomerative dusts include paper, cellulose, and cotton. Air, Standard (Conditions): Dry air at 70°F and 29.92 in Hg barometer pressure; air density is 0.075 lb/ft3 and specific heat is 0.24 Btu/lb-ft. Air-to-Cloth Ratio: Refers to filtration velocity and is also called air-to-media ratio. (See Vf.) Air-to-Media Ratio: Refers to filtration velocity and is also called air-to-cloth ratio. (See Vf.) Airfoil Fan: A type of fan wheel common on the clean side of a dust collector for higher air volume requirements. Its main attributes include quiet operation, highest efficiency of common industrial fans, and delicate fan blade that must have clean air so it cannot handle material.

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Airstream: Airflow in a process duct, vessel, collector, or fan. This is usually the captured airflow with dust or vapors in it before passing through a collector, or the cleaned airstream after the collector. Aluminum Mesh Filter: Standard pre- and/or post-filter in an Aercology Electrostatic Precipitator, Modular MediaFilter system, and spark trap/exhaust grill filter in the obsolete WeldAir Cartridge system. (See Metal Mesh Filter.) AmbientAer 2000: Obsolete Aercology prepackaged modular media filter unit designed for general ventilation of industrial particulate. The industrial version of the Smokebuster™. Ambient Air: The surrounding air of an environment, commonly referring to the air one would breathe. Also an Aercology ambient filtration system for light to moderate commercial or industrial applications. Ambient Air Collection: Capture of contaminant-laden air from the general environment instead of at the point of contaminant generation through the use of closed loop, recirculating air patterns. Ambient Air Collection Systems: Systems designed to capture contaminant-laden air from the general, ambient environment. Efficient systems are designed to create closed loop, recirculating air patterns for optimum contaminant capture. Also known as a free hanging or unducted systems. Ambient Air Tubesheet (AAT): A Torit pulse-jet cartridge system consisting of a tubesheet, yokes, conical and cylindrical cartridges, and pulse cleaning controls only. Dirty and clean air plenums, hopper, and dust storage to be supplied by the customer. AMM: An Air Management Module (AMM) serves to reduce the inlet dust loading and abrasion to a Downflo II cartridge collector by serving as a large drop-out box and reducing the airflow to less than 2,000 fpm (102 m/s) into the Extended Dirty Air Plenum (EDAP) inlet. (See Product Manual.) Amp Draw: Amp is an abbreviation for ampere, a unit of electrical current. Amp draw refers to the amount of electrical current (expressed in amps) being pulled by a source, typically a motor. AN Valve: An economical Torit rotary valve for most nuisance dust discharge requirements. The AN valve uses double wiper action to creative the best seal possible with flex-tip rotors. Ancillary: Accessories to a collection system. Examples include fans, rotary airlocks (valves), afterfilters, electricals/controls, broken bag detectors, and bin level indicators. Anemometer: Instrument used to measure the velocity of air. Anti-static Media: Epitropic, carbon-impregnated or stainless steel blended media used to assist in dissipating static charge build up. Special hardware and grounding provisions may also be required on the dust collector. Aqualine: Obsolete dual-branded DCE and Torit compact wet collector combining the air moving capabilities of a fan with the dust collection capabilities of a low-to-medium pressure drop wet collector. AR Inlet: Abrasion Resistant Inlet (AR Inlet) spans 1, 2, or 3 Downflo II modules and serves to reduce the airflow entering the dust collector to less than 2,500 fpm (12.7 m/s) (although 2,000 fpm

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(10.2 m/s) is recommended) to minimize damage to the collector and cartridges that could otherwise occur from abrasive dusts. (See Product Manual.) Asco*: U.S. based manufacturer of diaphragm and solenoid valves. *Asco is a registered trademark of Automatic Switch Company. ASHRAE Filter: A filter having an efficiency rating based on the American National Standards Institute / American Society of Heating, Refrigerating and Air-Conditioning Engineers test standard ANSI / ASHRAE 52.1 – 1992. This standard establishes procedures to measure the ability of air-cleaning devices to remove dust as they become loaded with a standard synthetic dust. The dust-removal performance is measured in two way: first by the percentage of the weight of the synthetic dust captured by the filter (ASHRAE Weight Arrestance); and second by comparing the blackening of targets both upstream and downstream of the air cleaning device using ambient atmospheric dust (ASHRAE Dust-Spot Efficiency). Atmosphere: Air pressure at standard conditions, 14.696 lb/in2, 29.92 in Hg (760 mm Hg), 407.52 in W.G. (10,340 mm W.G.). Attenuator: A silencer, typically used for reducing fan noise. Backward Inclined Fan Wheel: A type of fan wheel commonly placed on the clean side of dust collectors. Its main attributes include higher efficiency than radial or forward curve fans, non-overloading design meaning it will not result in a high amperage condition if operated under no load, and it is not intended for material handling. Barrier Filter: A filter using some type of media as a barrier for contaminant collection. Bin Balance: A tube connecting the bottom of a bin (or pail) to the inlet of a dust collector to provide a slight negative pressure in the bin (or pail) allowing a bag to be installed into the bin (or pail) without being sucked up into the collector. Bin Level Indicator: A device mounted in a dust collector hopper to tell if material is backing up into the hopper rather than exiting the collector through its dust discharge mechanism. The measuring portion of the bin level indicator may be a paddle type or probe. (See the Torit Products Parts & Accessories Book.) Black Light Lamp: A tool used for detecting fluorescent dust when testing a dust collector for possible leaks. (See the Torit Products Parts & Accessories Book.) Blast Gate: Sliding gate valve used to close off or partially open a duct to airflow; often used for balancing the airflow in branches or pickup from hoods in a dust collection system. Brake Horsepower (bhp): Actual delivered or required horsepower, as different from rated horsepower. Output of a motor required to drive a fan, feeder, conveyor, or other equipment. This must include any losses in a V-belt or chain drive. Branch Duct: Smaller or feeder ducts that contribute airflow to a main duct or plenum. These branches need to be sized for the expected air volume and velocity required, with some allowance for balancing in the field as requirements change. Bridging: The build up of material such that it fills the spacing or volume between filters. It is also used in referring to the build up of material between pleats in a cartridge filter. Donaldson Company, Inc. © 200 Dictionary-3 (5/03)

Broken Bag Detector: An instrument used to detect failure of dust collector filters, which may or may not be bags or cartridges. (See Torit Products Parts & Accessories Book.) Box Filter: The rigid, housed (or boxed) third-stage filter used in the Aercology MDV-10 Modular MediaFilter unit. Three box filters have been availableXE, XP, and XTfor various contaminants and mists. (See XE, XP, and XT.) Btu: British thermal unit, 1 Btu/h = 0.293 W. Bulk Density: Actual density of a dust or product as handled. This will vary from a fluidized lighter density, up to a settled density after enough time to allow air to escape and thus reach a stable maximum density. Bulk density is expressed in mass per unit volume, typically pounds per cubic foot or milligrams per cubic meter. Bypass: Unfiltered air escaping around a filter because it has not been properly sealed in place. °C: Degree Celsius in the metric or SI system or units. Carbon Filter: A filter used for collection of gas or vapor phase contaminants. Carbon filters can be in the form of filter media impregnated with carbon or as refillable trays or housings holding granular carbon. There are numerous types of carbon and impregnated carbons for specific contaminants with high quality, virgin, coconut shell carbon best suited for most general applications. Carbon filters are used in a number of Donaldson Dust Collection systems, particularly Aercology Modular MediaFilter systems. Cartridge Filter Element: A pleated porous module through which a gas or liquid is passed to separate out matter in suspension. Numerous configurations and shapes are possible including cylindrical, conical, and panel. Various media and materials of construction are also possible. Cartridge Filter Shaker: Obsolete Aercology intermittent-duty cartridge collector. Cased Unit: A stand alone dust collector consisting of dirty and clean air plenums including hopper and enclosed filter section. Does not include an integral fan. Centrifugal Mist Collector: An Aercology mist collector that operates on the principles of centrifugal action designed for straight oil applications on turning machines and lube oil sump reservoirs with fluids free of heavy amounts of fine, suspended solids. CF: Obsolete Aercology intermittent or continuous-duty cartridge collectors for dust and weld fume. CFM: Cubic feet of air flowing past a fixed location in 1 minute. CFS: See Cartridge Filter Shaker Chamber Silencer: An acoustically-lined enclosure covering the entire fan assembly to quite fan and motor noise. May include an outlet damper. Chevron Impinger: A filter assembly consisting of a series of metal plates fastened at an angle to the air stream. The plates have chevrons or inverted V's bent in the front and rear edge of the plate. The front chevron increases air velocity to increase impaction on the inner plate surface. If fluids are

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liquid, air velocity pushes collected liquids along plate wall into the V of the rear chevron where they drain from the filter. Aercology MediaFilter systems use these for mist and gelling or sticky contaminants or as mist prefilters for Electrostatic Precipitators. CI Valve: A high volume, high pressure, machined Torit rotary valve that is ideal for many applications handling process dust. Clean Air Plenum: An enclosed space which is full of matter, such as air. The clean air plenum is where air exits the collector. Cleaning, Continuous: Cleaning performed by injecting small quantities of high energy gas, usually compressed air, into each filter on a recycling basis to stabilize filter pressure drop and ensure continuous volume flow. A small percentage of filters are cleaned while the remaining filters continue to filter the incoming air. May also be referred to as pulse cleaning, or purging. Cleaning, Intermittent: Cleaning performed primarily by mechanical shaking under no-flow conditions, or when the collector is not operating. Coefficient of Entry Ce: Ratio of actual to theoretical flow entering a hood or inlet caused by the static pressure in the hood or duct inlet and affected by the design configuration of the hood or inlet. Collection Cell: A series of alternately charged ground and positive plates assembled into a housing as a collection filter in an Electrostatic Precipitator system. Particles charged by the ionizer in the EP system collect on the ground or positively charged collection plates where they are removed by cleaning (washing or impacting). Component Part: Any accessory to the collector, which may or may not be an outside purchased part. Cotton Sateen: The standard envelope bag material of construction offered in Torit Cabinet collectors providing excellent efficiency and dust release in most applications. CPZ: A mixture of carbon, potassium permanganate (with or without activated alumina) and zeolite used for complex gas/vapor applications. CS: Obsolete Carter-Day round-tube baghouse. Cubic Foot: Unit of volume measuring 1 foot long by 1 foot wide by 1 foot high, or its equivalents. Cyclone: A mechanical separator that uses the principle of centrifugal force to remove particulate from the airstream. Cyclopeel: Obsolete Torit side-mounted, abrasion-resistant inlet assembly based on cyclonic action. DC Cabinets: Obsolete Aercology dust collector dual -branded from the Torit Cabinet collectors. Denier: A unit of fineness for yarn equal to the fineness of a yarn weighing one gram for each 9000 meters. For example, 100 denier yarn is finer than 150 denier yarn.

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Delay Pulse Timer: An adjustable time delay device to increase the delay or off time between pulse cleaning cycles on cartridge collection systems. The timer opens the timer board power circuit for the programmed delay off time and restores power to resume pulse cleaning for the programmed on time. (See Timer.) d: Density factor of air at different conditions, d being 1 at standard conditions. The ratio of actual air density to density of standard air. The product of the density factor and the density of standard air (0.075 lbs/ft3)will give the actual air density in pounds per cubic foot; d x 0.075 = actual density of air, lbs/ft3. Delta P (∆P): Pressure drop across a collector or media, i.e. the difference in initial and final pressures. (See also Pressure, Differential.) Delta P (∆P) Controller: Brand name electrical controls offered by Torit. (See Electrical Components Product Manual chapter for more details.) Density: Ratio of the mass of a substance to the volume of the specimen. Depth Loading: The collection of contaminant throughout the entire thickness of the filter media rather than on the surface. Derate: To lower the rated capability of an electrical or mechanical apparatus. For example, derate the air-to-media ratio (or filtration velocity) for an application with high loading or requiring filter drainage. Aercology Modular MediaFilter systems are often derated to promote filter drainage on continuous operation mist collection systems. DF: The original Torit Downflo, pulse-jet duty cartridge collector that is now obsolete. DFT: The Torit Downflo II, pulse-jet duty cartridge collector featuring larger cartridges, larger inlet and outlet dimensions, lobed tubesheet holes, cartridges sloped at 15°, and clean air plenum bottom sloped at 26° to increase airflow through the collector with minimal increase in differential pressure. Diaphragm Valve: The diaphragm valve acts as an air switch for the pulse cleaning air. The diaphragm consists of a die cast metal housing, diaphragm and a spring. The diaphragm divides the valve into two chambers which are connected by a bleed passage that is smaller in diameter than the valve orifice. Diffusion: In mechanical filtration, the predominant filtration mechanism collecting very fine particulate, less than 0.1 micron in size. Because the dust particles are so fine, they are influenced by atomic forces, which cause the particles to move in the same general direction as the airstream and yet move independent of it. Direct Drive: Motor shaft mechanically coupled to the driven shaft so that both turn at the same speed, usually with negligible power loss. Dirty Air Plenum: An enclosed space which is full of matter, such as air. The dirty air plenum is where contaminant-laden air enters the collector. DLM V: The abbreviation for a DCE Dalamatic insertable collector.

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DOP Efficiency Test: A filter efficiency test using dioctylphthalate mist consisting of particles 0.3 microns in diameter as the test aerosol. The concentration of particles (by count) measured upstream and downstream of the filter determines the efficiency. This method is generally used to rate very high efficiency or “absolute” filters because of the small particle size of the contaminant and the very high efficiencies usually demanded (99+ percent). The DOP test is usually applied only to filters for “clean rooms” or other special applications requiring very clean nearly sterile air. Double Pass: Running two identical filters or filter modules in series to promote high collection efficiency or increased contaminant capacity. Double pass units are used primarily in Aercology Electrostatic Precipitator and Modular MediaFilter systems. Downtime Cleaning: Cleaning of filter media done when the collector’s fan is not operating and dust-laden air is not continuing to be filtered in the collector. For example, downtime cleaning of a Downflo II collector would occur after the system fan is turned off. Drive Losses: Losses in slippage and friction in a drive transmission, usually about 7 percent in a V-belt drive. Drier: A device used to dry the compressed air used for continuous cleaning of a pulse jet duty dust collector. There are a variety of compressed air dryers including refrigerant and regenerative. (See Torit Products Parts & Accessories Book.) Drop Out Box: A large, airtight box or container with clean out used to reduce the in line air velocity of a ducted, source capture collection system. The box is typically located close to the contaminant source where large contaminants are initially drawn into the duct system. The reduced air velocity in the box causes larger contaminants to drop out of the air stream. Drum Sentry: A Torit pneumatic device used to estimate the amount of material collected in a 55-gallon drum. Effective on heavy dusts. DU: The abbreviation for the obsolete DCE Dalamatic unit collector. Duct: Enclosed tube or passage for constraining air or gas flow within the enclosure until it is delivered to a desired destination, such as a collector or fan, or exhausted to atmosphere. Ducted System: Typically a collection system utilizing ductwork or piping to convey clean or contaminant laden to or from the unit. Dummy Cell: Slang term for Air Management Module (AMM). Dust: Solid particles, usually small and light enough to be conveyed or carried in an airstream. Dust Cake: The layer of dust formed on top of filtration media. The dust cake does the bulk of the filtering by filling any gaps between the media fibers. Dust Collector: Separator of dust from an air or gas stream. Duty Cycle: Refers to a collector’s ability to operate intermittently or continously. (See Intermittent Duty and Continuous Duty.)

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EDAP: An Extended Dirty Air Plenum (EDAP) extends the height of the dirty air section of a Downflo II cartridge collector and is typically used with Air Management Modules to prevent filter abrasion. (See Product Manual.) Edging: On the Unimaster, a one-piece polyester sleeve that is slid over the inserts (cages) to prevent the envelope-style bag from being cut by the insert (cage). Efficiency: Filter efficiency measures how much contaminant the filter removes and is typically expressed as a percent of incoming dust removed. Electrostatic Precipitator (EP): An obsolete Aercology collection system. In general, an electrical device for removing suspended impurities such as dust, smoke, fumes, or mist, from air or other gases. In the Aercology system the air or gas moves through an ionizer that charges the suspended particles. The charged particles are attracted to plate surfaces with an opposite charge in the collection cell and removed from the air stream. Endcap: These caps hold together the ends of a cartridge filter (liner and media). A hole in the top endcap allows filtered air to exit the filter and allows the cleaning air pulse to enter in the reverse-flow direction. Entrainment: The phenomena of dirt being drawn into a moving air stream. Used in ambient systems to remove contaminants from the general air. Entry Loss he: Loss in pressure (in W.G.) caused by air flowing into a hood or duct inlet, due to the vena contracta of the air stream and shape constrictions in the inlet or hood. EP: Abbreviation for explosion proof motor as well as the obsolete Aercology Electrostatic Precipitator. (See Motor and Electrostatic Precipitator.) Exhaust Air: Air exiting a process or air moving device or that has been processed by a dust, fume, smoke, or mist collector and is exhausted outside of the work environment, typically outside. Exhaust Silencer: Noise reduction device located on the exhaust outlet of a fan. May also be called a stack silencer.

Donaldson Company, Inc. © 200 Dictionary-8 (5/03)

Extension Plenum: A bolt-on or welded box like extension off an inlet or outlet plenum. In most cases they are used on inlet plenums on vertical units with restricted space requirements. They eliminate the need for 90-degree elbows and allow vertical ducting to be run alongside the unit. Extension plenums are also used for mounting source capture mechanical arms. Externally Supported Arm: An adjustable, self-supporting, source capture hood and duct system with clutch or arm supports external to the duct system. ExtraLife Cleaning System: A combination of proprietary-shaped venturi and optimized configuration of pulse valves and blow pipes used to improve pulse cleaning by providing more pulse pressure at the top end of the filter cartridge (near the tubesheet) without reducing pressure in other areas. A standard offering on Downflo II dust collectors for improved performance and extended cartridge life. °F: Degree Fahrenheit. F Series Valves: Torit rotary valves that are ideal for pneumatic conveying applications and when conveying sticky or abrasive materials. The F Series valves feature an “air sweep” design using filtered air from a blower to aerate the material moving through the valve to eliminate pocket build up. ft/min: Feet per minute, a measure of velocity. ft/min (Surface): Surface feet per minute, velocity over a surface. ft/s: Feet per second, a measure of velocity. ft2: Square feet, a measure of area. ft3/min: Cubic feet of air flowing past a fixed location in 1 minute (cfm). ft3/min (standard): Cubic feet per minute, at standard conditions of temperature and humidity (scfm). Fan Curve: Each fan has an associated graphic, or fan curve, that shows airflow on the X-axis and static pressure on the Y-axis depicting the capability of the fan. The fan curve can be used to select the appropriate fan for system airflow and static requirements. The fan should always be determined at a point on the curve to the right of the peak. Fan Wheel: The fan wheel is the component of a fan that actually moves the air. The fan wheel can be described by its type, height, diameter and bore size. There are many types of fan wheels such as forward curve (squirrel cage), radial blade (material handling), backward inclined, and airfoil. The bore size refers to the size of the hole in the center of the wheel that the motor shaft inserts into in order to mechanically rotate the fan wheel. FD/FDV: The original Aercology Modular MediaFilter line. On standard models, FD designates horizontal mount for dry or ambient capture applications, and FDV designates source capture vertical mount for wet or mist applications. FDV was obsoleted in 2001.

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Fiberglass Filter: A filter containing a filtration media made from borosilicate fibers with efficiency dependent upon fiber size, density and loft thickness. Low efficiency prefilters (furnace type) to high efficiency Vee bags (95% ASHRAE rated) are typical examples. Fibra-Web Filters: Donaldson Company’s proprietary filters that use nanofiber filtration technology in combination with synthetic filter media to deliver better cleaning efficiency, lower cost per cubic foot of air per minute (cfm) and reduce energy consumption through improved filtration performance. (See nanofiber filtration) Fibrous: A dust that is irregularly shaped, generally of long, thin configuration. Fibrous dusts are typically over 10 microns in length and tend to be agglomerative. Filter: A porous article or mass through which a gas or liquid is passed to separate out matter in suspension. In this case, filter refers to just the filter media itself, either cartridge filters or a bag filters. Filter can also be an apparatus containing a filter medium. In this case, filter refers to the entire dust collector including the actual filter media. Filtration: The mechanical action of separating matter out of suspension, using a filter medium such as a cartridge filter or bag filter. Filtration Velocity: Filtration velocity, or velocity of the airstream when it enters or passes through the filter media, often referred to as the air-to-cloth (A/C) or air-to-media ratio (AMR). It is important to know the units of measure used for the ratio. For example, 2:1 in English units would mean 2 cfm per ft2 of filter media. However, 2:1 in metric units would mean 2 m3/hr per m2 of media. It may be necessary to convert units. Flange Connector: A bell mouth inlet connector attached to an enclosure or used as a hood for source extraction. Used heavily with the Aercology Centrifugal Mist collector, these spun fittings make excellent pickup hoods for small applications. Flex Arm: A general term for the FT-500 arm in the Trunkline Products due to it’s ability to flex into position for optimum worker use and dust capture. Flex-Flap2: Obsolete DCE unique dust control device using grating and flap-type seals on dump hoppers to reduce the volume of air required to control dust. Fluorescent Light: See black light lamp. Forward Curve Fan Wheel: Type of fan wheel, also referred to as a squirrel cage, with quiet operation, non-material handling capability, and low space requirements. Free Hanging System: See Ambient Air Collection Systems. Full Load Amps: The amp draw of the motor when it is operating at its peak horsepower. Fumes: Often noxious suspension of minutely small solid particles in a gas or air, formed by the condensation of vapors with solid particles, or any smoke, vapor, or gas especially when irritating or offensive. g: Gram of weight, 453.6 g = 1 pound (lb) = 16 oz = 15.432 grains (gr).

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Gauges: General term for Magnehelic or Photohelic gauge. *Magnehelic and Photohelic gauge are registered trademarks Dwyer Instruments, Inc. Gases: Formless fluids which tend to occupy uniformly an entire space at temperatures and pressures which do not change the substance into either a solid or liquid. Gasket: A soft polymer ring used to form a seal such as an airtight seal between a cartridge filter and a dust collector’s tubesheet. Glazing: The melting and smearing of a microscopic layer of media fibers to form a slick surface for better dust release on bag filters. It is also known as “eggshell” finish. It provides short-term improvements for dust cake release but may impede airflow (causing additional pressure drop). A glazed finish is a standard option for polyester felt. Goyen: An Australian based manufacturer of solenoid and diaphragm valves and their enclosures. gr: Grain of dust, an extremely fine weight measure, where 7,000 gr = 1 lb, 1 gr = 0.0648 g = 0.0001429 lb, 1 gr/ft3 = 2288.1 mg/m3, and 0.01 gr/ft3 = 22.88 mg/ m3. Gravity, Specific, (sp. gr.): Ratio of the mass of a unit volume of a substance to the mass of the same volume of a standard substance at a standard temperature. Water at 39.2°F is the standard substance usually referred to. For gases, dry air at the same temperature and pressure as the gas, is often taken at the standard substance. Grounding: Providing a path for electrical flow through a dust collector to ground, or grounded surface such as the earth, to prevent static potential build up. h: Hour, a 60-min time period. H: Obsolete Carter-Day fan line. he: (See entry loss.) HEPA: (High efficiency particulate arrestance) High efficiency particulate air filter that is 99.97 percent efficient at collection of dust down to a 0.3 micron size. Hood: Particular design of inlet used to capture dust- or fume-contaminated air or gas and conduct it into the collection and exhaust duct system. Hopper: A receptacle for delivering material from the dirty air plenum/filter section to a discharge and storage device. Hoppers may be pyramidal, conical, or trough with various outlet shapes and sizes. In general, Donaldson Dust Collection hoppers are not intended for storage of collected contaminant. Hopper Unit: For DCE brands, a dust collector consisting of clean air and dirty air plenums including integral fan. It does not include a hopper, but it is provided with a flange for mounting to a customer’s purpose-built hopper. Horizontal Mount: A collector mounted so airflow through the filter system is horizontal. Typically inlet and outlet airflow will also be on the horizontal plane. The standard mounting for an efficient, ambient collection system. Donaldson Company, Inc. © 200 Dictionary-11 (5/03)

hp: Horsepower, a measure of motive or electric power. Humidity, Absolute: Weight of water vapor per unit volume in pounds per cubic foot or grains per cubic centimeter. Humidity, Relative: Ratio of the actual partial pressure of the water vapor in a space to the saturation pressure of pure water at the same temperature. HV: Obsolete Carter-Day high velocity cyclone. HVAC: Heating, ventilating, and air conditioning. Hydrolysis: A chemical process of decomposition that involves splitting of a molecular bond and the addition of elements of water. Synthetic fibers made from condensation polymers are subject to hydrolysis, including: polyester, nylon, polyamide (P-84), and Nomex. Many production processes generate moisture and chemistry in the presence of elevated temperatures and form the ideal conditions for hydrolysis. The three elements of elevated temperature, moisture, and temperature must be present for hydrolysis to become activated. Hygroscopicity: The characteristic describing if a dust will readily take up and retain moisture. Hygroscopic dust examples include acids, starches, and cement. Inch of Water, in W.G.: Unit of pressure equal to the pressure exerted by a column of liquid water 1 inch high at a standard temperature. in2: Square inch, a measure of area. Impactor: An electrical, automatic self-cleaning system for the Aercology Electrostatic Precipitator systems used on heavy welding fume applications. A drive motor would lift and release a "hammer" that provides an impact to the collection components to dislodge collected fume particulate. Impinger Module: A filter module housing with one or more chevron impingers. (See Chevron Impinger.) Inertial Impaction: In mechanical filtration, the predominant filtration mechanism collecting micron-sized particulate. Inertial impaction occurs as the airstream is displaced by the media fiber while the dust particle continues on its original course because of its mass. Inlet Cone: An aerodynamic air inlet to an air moving device or fan. Also known as an inlet ring. Inlet Flange: Also called airguide inlet or entrance panels, inlet flanges are used primarily in ambient collection systems. The flange is attached to the unit's inlet and acts as a funnel, increasing the inlet capture zone on the unit and improving collection system efficiency. Inlet Plenum: An air chamber, or add-on box, that serves as the air entry point, velocity reduction and air distribution system into the filtration system. Collars for ducting or piping are attached to the inlet plenum. Insertable: A dust collector configured with open filter media allowing the filters to be inserted into the process, such as for bin venting.

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Insert: Cage. A mechanical device that supports envelope or bag filters. Interception: In mechanical filtration, the predominant filtration mechanism collecting 0.1 to 1 micron size particulate. Interception occurs when a dust particle comes close enough to a fiber to adhere to it and is a result of particle trajectory. Internally Supported Arm: An adjustable, self-supporting, source capture hood and duct system with clutch or arm supports inside the duct system. Ionizer: The component that charges particulate in Electrostatic Precipitator systems. The Aercology EP ionizer includes charged thin tungsten wires supported between grounded metal vanes to charge, or ionize, particles drawn into the system. The downstream collection cell removes charged particles. Jet Tube: Pipe that transports compressed air from the diaphragm valves for cleaning. Also known as pulse pipe. Junction Box: A box where wires and connections from electrical devices, typically motors, are located for easy accessibility by a field electrician. The junction box may be mounted on the collector and not act as a motor starter. However, a motor starter may easily be wired to a junction box. °K: Degree Kelvin, of temperature. KST: The explosibility index of a particular dust sample. It is unique to each dust sample and is the maximum rate of pressure rise inside a vessel during the deflagration of the dust sample. The Kst value equals the slope of the curve where the pressure is rising versus time, and is in the units of (bar⋅meter)/second. The customer is required to provide the KST value to Torit Products. lb: Pound, a measure of weight. L/D Ratio: Length-over-diameter ratio for an enclosure. A term used in explosion vent calculations. Leak Light: See Black Light Lamp. Liner: Perforated or expanded metal located inside a cylindrical pleated media cartridge to help holds its cylindrical shape. The inner liner also gives the cartridge filter longitudinal rigidity. Sometimes an outer liner encircles the media to provide added cartridge strength, preventing blowouts during pulse cleaning and protecting the media from abrasive dusts. Lint Collector (LC 2000): Obsolete Torit bulk bag unit for collecting lint and cloth fiber. Loading: Dust loading refers to the actual concentration of particles in a cubic foot of space. Dust loading is expressed in units of grains per cubic foot (gr/ft3) or milligrams per cubic meter (mg/m3). A grain is a unit of mass, where 7,000 grains equals on pound mass. For reference, air or furnace type barrier filters are used on applications with dust loadings

• Moderate loading = 1-2 gr/ft3 (cartridge collector), and • Heavy loading ≥ 5 gr/ft3 (baghouse collector)

(See also Depth Loading and Surface Loading.) Lower Explosive Limit, LEL: Lower limit of flammability or explosibility of a gas or vapor at ordinary ambient temperature, expressed in percent of the gas or vapor in air by volume. This limit is assumed to be constant for temperatures up to 250°F (121°F). Above these temperatures, it should be decreased by a factor of 0.7 since explosibility increases with higher temperatures. Magnehelic* Gauge: Pressure measuring instrument that senses the difference in air pressure exerted on opposite sides of a diaphragm, and by means of a magnetic linkage from the diaphragm to a pointer, indicates the pressure difference by the pointer motion. Usually the gauge reads pressure by inches water gauge for dust collection systems. *Magnehelic gauge is a registered trademark of Dwyer Instruments, Inc. Manifold: A tank of varied configuration where compressed air is stored before being used to pulse clean a dust collector. Manometer: Instrument for measuring air or gas pressure. It is essentially a U-tube partially filled with a liquid and so constructed that the amount of displacement of the liquid indicates the pressure exerted on the sensing end of the manometer tube. Mattress: On the Unimaster, a one-piece multi-pocket filter. MC: Obsolete Torit Mist Collector utilizing fiberglass envelope bags. Replaced by the Dryflo. MDV: Aercology Modular MediaFilter II systems with advanced features for wet applications. (See Modular MediaFilter II.) ME: Mechanical efficiency. Mechanically Generated: Contaminants generated by mechanical movements such as coolant mist from rotating chucks, spindles, and heads or dry dust from sanding discs on wood. Mechanically generated contaminants tend to be larger than those thermally generated. Media: Material that separates contaminant from the airstream. Media may be of various constructions (nonwoven, felt, cellulose, synthetic, etc.) and formed into numerous configurations (bags, cartridges, etc.).

Donaldson Company, Inc. © 200 Dictionary-14 (5/03)

Metal Mesh Filter: Cleanable, wire mesh or slitted expanded metal mesh filter made from aluminum, zinc plated steel, or stainless steel. Standard mesh layer depths are one or two inches. Used either as a pre- and/or post-filter in Aercology Electrostatic Precipitator, Modular MediaFilter systems and spark trap/exhaust grill filters in the obsolete WeldAir Cartridge system. mg: Milligram, or one-thousandth of a gram. MIC: Obsolete Torit intermittent-duty, mechanical-shaker, round tube baghouse with airflow from inside to outside of the bags. Micron: Unit of length measurement or size. It is one-thousandth of a millimeter, or one-millionth of a meter, or approximately 1/25,000 of an inch. It is identical to a micrometer. min: Minute of time. Minimum Duct Velocity: Minimum airstream velocity required to move a specific type of dust particulate in the airstream, usually taken to be a conservative or safe conveying velocity that keeps the dust suspended in the airstream, but not higher than necessary for this suspension. Mini-Scrubber: Obsolete Torit two-stage wet collector complete with sump, floats, and return pump for use on dust. Mist: Small droplets of materials that are ordinarily liquid at normal temperature and pressure and are suspended in the air, like water in the form of droplets floating or falling in the atmosphere, or a suspension of a finely divided liquid in a gas, or a fine spray. mm: Millimeter, or one-thousandth of a meter. Modular MediaFilter: A flexible line of Aercology collection systems for capture of mist, dust, smoke, fume, and gas/vapors as individual or combined contaminants. The original FD series is available in horizontal mounting for dry particulate or ambient applications (FD) and vertical mounting for mist and wet applications (FDV). The FD and FDV were obsoleted in 2001. Specific modules included:

Prefilter modules • FI – Impinger (prefiltration of mist or sticky contaminants) • FIII – Triple Impinger (severe mist applications or heavy loading of sticky contaminants) • FM – Multivee module (prefiltration of dry or slightly wet or sticky dust) Intermediate modules • FD – 1” disposable, 4” 40% ASHRAE Multivee and 95% ASHRAE Vee-bag • FDV- 4" Chevron Impinger, 1" Aluminum Mesh and 95% ASHRAE Vee-bag HEPA module • FH – 1” prefilter, HEPA filter (heavier smoke or fume) Gas/Vapor modules • FC1 – 45 lb. refillable carbon cell, 1” 40% ASHRAE Multivee post filter • FC2 – 90 lb. refillable carbon trays, 1” 40% ASHRAE Multivee post filter Fan module • FB – Adjustable rpm belt drive industrial blower

Modular MediaFilter™ II: A flexible line of Aercology collection systems constituting a cabinet upgrade and redesign of the original Modular MediaFilter system targeted for mist applications. Donaldson Company, Inc. © 200 Dictionary-15 (5/03)

Modules are similar to those provided in the original Modular MediaFilter units with a nomenclature change from F to M. Upgrades include leak resistant features, improved filter sealing, add-on filter options, and easier maintenance. Modular MediaFilter™ Horizontal Series: A flexible ceiling mount, horizontal design system designed to collect mist, smoke, dust, fumes, and odors. The Source Collector includes: 4-inch impinger, 1-inch aluminum mesh, and 95% ASHRAE high-loft fiberglass Vee-Bag. The Ambient Collector includes: 4-inch Multi-Vee and 95% ASHRAE high-loft fiberglass Vee-Bag. Introduced in 2002. Moisture: Moisture content refers to the amount of water in the system airstream. This is an important consideration for high temperature applications or those applying cartridge filters. The moisture content can be determined by knowing the dry bulb and wet bulb temperatures and using a psychrometric chart. Motor: A rotating machine that transforms electrical energy into mechanical energy. For example, motors are used to rotate fan wheels and rotary valve rotors. Basic motors are identified by their operating voltage/hertz/phase of electrical power input, TEFC (Totally Enclosed Fan Cooled) or EP (Explosion Proof) construction, frame size and type, and shaft size. MSDS: Material Safety Data Sheet contains important environmental, safety and health information of material hazards. MTJ: “Modular Torit Jet”, round-bag, bottom-entry baghouse replaced by the Modular Baghouse. Multi-Vee: A medium efficiency (40% ASHRAE rated) pleated filter in a beverage board frame. Used as an intermediate, medium efficiency filter in Aercology Modular MediaFilter systems. Nanofiber Filtration: Technology whereby a layer of 0.2- 0.3 micron diameter fibers are applied to the surface of a media substrate to increase surface loading, capture sub-micron contaminants and improve dust release during pulse cleaning. Needle Felt: Filtration fabrics manufactured by mechanically bonding layers of staple fibers to a base cloth (scrim) by means of a fabric interlocking machine. Needles are used in this machine to punch the fibers through the fiber mass and lock them to each other. NEMA: A numerical rating indicating the environmental conditions for which an electrical enclosure is intended to be used in. (See also the National Electrical Code.) Common NEMA ratings used in dust collection are:

• NEMA 12: Intended for indoor use to provide a degree of protection against dust, falling dirt, and dripping water. (Industrial use, dust-tight, and drip-tight indoor.)

• NEMA 13: Intended for indoor use to provide a degree of protection against dust, spraying water, oil and noncorrosive coolant. (Oil-tight and dust –tight indoor.)

• NEMA 4: Intended for indoor or outdoor use primarily to provide a degree of protection against wind blown dust and rain, splashing water, and hose-directed water. (Water-tight and dust tight.)

• NEMA 4X: Intended for indoor or outdoor used to provide a degree of protection against windblown dust, rain and sleet. (Water-tight, dust-tight, and corrosion-resistant.)

• NEMA 9: Intended for indoor use in locations classified as containing hazardous dusts in Class II, Groups E, F, and G as defined by the National Electrical Code.

Donaldson Company, Inc. © 200 Dictionary-16 (5/03)

• NEMA 7: Intended for indoor use in locations classified as containing hazardous gases in Class I, Groups A, B, C, D as defined by the National Electrical Code.

Nomex*: A synthetic fiber (aramid felt) that will withstand temperatures up to 400°F (204°C) in dry conditions. If moisture or chemistry is present, hydrolysis may occur. The flex and abrasion resistance of Nomex is excellent and better than most synthetics. *Nomex is a registered trademark of EI Dupont de Nemours. Odor: A strong, distinctive smell. Odors can be airborne particulates or from gas/vapors. Oleophobic Treatment: Fluorocarbon treatment similar to Scotchguard* available on DCE bags to provide added dust cake release when handling sticky and agglomerative dusts. *Scotchguard is a registered trademark of 3M Corporation. On-time: The length of an air cleaning pulse often measured in milliseconds. Off-time: The length of time between air cleaning pulses. P-84: A synthetic fiber that will withstand temperatures up to 450°F (232°C). P-84 is a tri-lobal fiber that provides a very high efficiency due to the larger surface area of each individual fiber. P-84 is a condensation polymer subject to hydrolysis if chemistry or moisture is present at elevated temperatures. Pes: The enclosure strength of a vessel, representing the pressure limit of the enclosure. When this pressure is exceeded, the housing ruptures and an explosion occurs. Pmax: The maximum pressure generated when an optimal mixture of fuel and oxidant react in a closed vessel. Pred: The reduced pressure achieved by allowing gases to escape an enclosure. This value is selected as a design point below the enclosure strength. Pstat: The pressure at which the explosion relief vent opens and starts letting gases escape from the housing. This is usually a fixed number for a particular style explosion relief vent and has a value around 0.1 bar. Paddle Wheel: A type of bin level indicator. (See Bin Level Indicator.) Papyrus: The standard off-white/grayish paint color of DCE collectors. PDV: Obsolete Aercology Modular Media Filter™ II system with direct drive fan. Permeability: Filter permeability measures how much air can pass through the clean filter at a given pressure drop. A high-permeability filter is advantageous because it produces a low pressure drop across the filter and reduces the energy required to operate the dust collector. Photohelic* Gauge: Differential pressure gauge and switch that incorporates two adjustable set point indicators and switches. Pressure sensing uses the same principle as the Magnehelic gauge, and switching is accomplished by phototransistors that detect the gauge pointer when it reaches either set point of pressure level. Each set point is controlled by a knob on the front of the gauge.

Donaldson Company, Inc. © 200 Dictionary-17 (5/03)

When either phototransistor is activated, it then actuates one of two internal relays, and contacts on both relays may be connected and used for control action circuits. *Photohelic gauge is a registered trademark of Dwyer Instruments, Inc.

• Split Photohelic: The relay pack containing the electronics is mounted remotely from the gauge. The two pieces are connected by a cable. This configuration is often used when the Photohelic is mounted in a pulse-jet control panel enclosure because it maximizes the use of space inside the enclosure while allowing mounting of the gauge conveniently in the panel front.

• Weatherproof Photohelic: The Photohelic gauge is mounted in a weatherproof (NEMA 4X) housing. Recommended for outdoor locations.

PIC: Obsolete pneumatic, intermittent, round-bag, bottom or top-entryTorit baghouse with airflow from inside to outside of the bags. Pitot Tube: A device that can be used to measure the velocity pressure in a duct and its corresponding volumetric air flow. (See also Industrial Ventilation Manual.) PJ: Obsolete Torit round-bag, continuous-duty baghouse with rectangular or round housing configuration. The rectangular configuration replaced by the Torit PJD collector. PJD: Torit “Pulse-Jet Duty” bottom entry, round-bag, dirty-side filter access, continuous-duty baghouse. ppm: Parts per million. Plenum: An enclosed space which is full of matter, such as air. In dust collection, commonly referred to the dirty air plenum (where air enters the collector) and the clean air plenum (where air exits the collector). Plug Fan: An unhoused direct-drive fan, such as used on the Aercology PDV unit and MediaFilter systems with custom fan packages. Polyester: The most common bag filtration fabric offering good resistance to most atmospheres at ambient temperatures. Polyester is the most cost effective media at low temperatures and can withstand temperatures up to 275°F (135°C). Polyester is a condensation polymer subject to hydrolysis at higher temperature with chemistry or moisture. Polypropylene: A synthetic fiber best known for its moisture resistance. Polypropylene will withstand temperatures to 180°F (82°C). Porthole Cover: Filter access cover for a Downflo cartridge collector.

Donaldson Company, Inc. © 200 Dictionary-18 (5/03)

Potassium Permanganate: A dark purple crystalline compound, KMnO4 used as an oxidizing agent, chemisorbant, and disinfectant in deodorizers and dyes. It is commonly used in wet scrubbers for gas/vapor and odor removal applications. It is also mixed with activated alumina and pelletized for use in refillable housings or trays, and added as an impregnant for a filter media. Potting Compound: The material that attaches the filter media to the endcaps and prevents unfiltered air from passing around the media. Power Pack: An air moving device, which may or may not include the motor. Pre-coat: A method of managing dust collector performance by applying varying amounts of an inert substance to the filtration media at collector start-up to assist in build up of a dust cake. Common pre-coat mediums include limestone, processed limestone such as Duramite, and Neutralite. Pressure Demand Cleaning: Cleaning controls based on pressure drop such as when using a Photohelic* gauge. *Photohelic gauge is a registered trademark of Dwyer Instruments, Inc. Pressure, Differential: Pressure drop across a collector or media, i.e. the difference in static pressure between the upstream and downstream sides of a collector due to the resistance of the filters. Torit dust collectors are rated in pressure drop across the collector, indicating that all static pressure losses for the entire device are accounted for including the inlet, outlet, and media losses. Pressure, Static (SP): Pressure exerted in all directions by a fluid at rest. For a fluid in motion it is exerted in a direction normal or perpendicular to the direction of flow. It is usually expressed in inches water gauge for dust collection airstreams, and it can be positive or negative. SPa is actual static pressure at other than standard pressure. SPh is hood static pressure. SPs is static pressure at standard pressure. Pressure, Total (TP): Algebraic sum of the static and the velocity pressures. Pressure, Vapor: Pressure exerted by a vapor. The term vapor pressure is sometimes used synonymously with saturated vapor pressure. Pressure, Velocity (VP): Kinetic pressure measured in the direction of flow, which is necessary to cause the fluid to flow at a given velocity, usually measured by inches water gauge. It is always positive. Primary Filter: The main working filter in a collection system. A thick, polyester, felt filter in the Aercology Centrifugal Mist Collector responsible for coalescence of fine mist particles and efficient collector operation. ProBooth: Obsolete Torit self-contained work station incorporating dust control with optional noise control and lighting. Target market was woodworking industry. psi: Pounds per square inch, a measure of pressure. psid: Pounds per square inch differential, a measure of pressure difference. psig: Pounds per square inch gauge, a measure of pressure difference from the surrounding atmosphere. Donaldson Company, Inc. © 200 Dictionary-19 (5/03)

Psychrometric Chart: A graph of properties (temperature, relative humidity, etc.) of air at a single pressure, typically 29.92”Hg or 101.325 Pa. It is used to determine how these properties vary as the amount of moisture (water vapor) in the air changes. It provided the information required to calculate changes in the volumetric flow rate and density of the gas. Psychrometric charts can be located in the Industrial Ventilation Manual. PTFE: Polytetrafluoroethylene is a water-repelling material that is inert to concentrated mineral acids, organic acids, alkalies, oxidizing agents, and organic solvents at elevated temperatures. PTFE has a low coefficient of friction resulting in good cake release during pulse cleaning. A common trade name is Teflon*. Donaldson offers PTFE membrane coating on media under the brand name Tetratex. *Teflon is a registered trademark of EI Dupont de Nemours. Pulse Duration: On-time. The length of an air cleaning pulse often measured in milliseconds. Pulse Interval: Off-time. The length of time between air cleaning pulses. Pulse-Jet Collector: A dust collector utilizing high pressure, low volume compressed air for cleaning of the filters. Pulsing: A method of cleaning cartridge or bag filters by injecting small quantities of high energy gas, usually compressed air. (See also Cleaning, Continuous.) Purging: A method of cleaning cartridge or bag filters by injecting small quantities of high energy gas, usually compressed air. (See also Cleaning, Continuous.) Q: Quantity of airflow, measured in volume per unit of time, typically ft3/min (cfm). Equal to the product of average velocity in fpm and cross-sectional area in ft2. Q=VA. Quick Release Sealer Gear: A DCE device ensuring sealing of the pail with a lever providing easy service of the pail. °R: Degree Rankin, of temperature. Racetrack Air Pattern: An arrangement of free hanging (or ambient) collectors in which the clean air from one unit blows into the dirty air inlet of another unit throughout a facility to create a circular, recirculating or racetrack air pattern. The air pattern entrains airborne contaminants and pushes them into the inlets of downstream units for removal. Radial Blade Fan Wheel: A type of fan wheel often referred to as an industrial exhauster. Its main attributes include durable fan design capable of handling material through the wheel and medium noise level. RA: Torit “Reverse Air” is a high volume baghouse similar to the RF except a large fan is positioned inside the clean air plenum which blows clean air continuously into the bags; the RF PD blower pump and external pressure tank are removed; the rotating manifold arms utilize a different design; and a suspended bearing support is used for the manifold instead of the pivot bearing desing.

Donaldson Company, Inc. © 200 Dictionary-20 (5/03)

RAL: Rotary air lock, a type of volumetric feeder or discharge equipment that has six or eight radial vanes that make up the rotor; the rotor is rotated inside a housing with close clearance around the rotor, and there is an upper inlet opening and a lower outlet opening.

Rapper: Another name for impactor. (See Impactor.) Recirculating Air Pattern: An arrangement of capture and return points that complement one another. For example, capture of weld fume at the ceiling with clean air return at the floor. Another example is a racetrack air pattern which is critical for system efficiency in ambient collection systems. Particles that miss collection by downstream units are re-entrained in the overhead air pattern and eventually directed into a unit for removal. Re-entrainment: The phenomena of the cleaned off dust from a pulse jet collector landing back on the filter media rather than falling out of the collector. Resistance: Air passing through a collection system typically travels through duct, filters, and other obstacles that tend to restrict its flow because of friction. This restriction is referred to as resistance. There is a total resistance of the system as well as the resistance caused by the filters. Return Air: Cleaned or filtered airstream exhausting from a dust collector that is returned to a process, or to a plant area, as replacement or make-up air supply. RF: Torit “Reliable Fire” low-pressure, high volume, pulse-jet duty, oval bag collector with scrolled dirty air inlet and single hopper discharge and utilizing a PD pump for cleaning air. RH: Relative humidity; ratio of actual partial pressure of water vapor to the saturation pressure. RJ: An obsolete Carter-Day pulse-jet duty, oval-bag collector historically applied in the coal and grain industries. RP: Obsolete Carter-Day round-bag, pneumatically cleaned baghouse. Roof-Drill Units (RDDC): Unpowered Torit rectangular collector with one to three cartridges and cyclone precleaner used in underground mining in conjunction with roof bolters. rpm: Revolutions per minute, a measurement of rotating speed. RVS (Round Vibra Shake): Obsolete Torit intermittent duty cartridge collector. Ryton: A high temperature, chemically resistant synthetic fiber capable of handling temperatures up to 375°F (190°C). Ryton will not hydrolyze and replaced Nomex under elevated temperature, high moisture conditions. scfm: Cubic feet per minute, at standard conditions of temperature and humidity. Sack Tipping Station: A bag dump station, without slitter, available on DCE brands.

Donaldson Company, Inc. © 200 Dictionary-21 (5/03)

Scrim: The openly woven substrate fabric that forms the base of needle felts. This light weight woven fabric can be seen in the middle of the “felt sandwich” if seen in a cross-section view. Many regard the scrim as the reinforcing bar in the felt. The scrim is regarded as being responsible for lending the burst and tear strength to felt fabric. SDF: Obsolete Torit continuous duty cartridge collector. Seal Frame: Tubesheet. The divider between dirty and clean air plenums in a dust collector where the filters are typically attached by an insert (cage). Sealing Ring: A collar on the open end of an envelope-style DCE Dalamatic bag that provides a seal on the clean air side of the seal frame (tubesheet). Seasoning: The process of building up a dust cake on a filter media. Secondary Filter: A back up filter in a collection system. A spun bonded polyester filter located behind the rotating drum in the Aercology Centrifugal Mist Collector to entrap any droplets that miss the oil collection slot for the drain system. Seismic Zone: A geographic area, or “zone”, identifying that regions’ likelihood to have an earthquake, or seismic activity. Seismic zone maps are used in the Uniform Building Code. Seismic zones range from zero (southern Alabama) to four (southern California). Sheave: A grooved wheel or pulley. Pitch diameter may be fixed or adjustable in variable RPM systems. ShopPro: Obsolete Torit intermittent-duty cartridge collector designed for the wood shop. Sieving: In mechanical filtration, the predominant filtration mechanism collecting larger particulate, greater than 10 micron. Sieving occurs when the particle is physically too large to fit between two or more fibers. Sieving is what stops a flying inset from going through a window screen. Silencer: An optional, add-on, square or round acoustically lined extension duct added to the fan exhaust outlet to reduce exhaust air noise (similar to a muffler). Silicone Treatment: A standard bag treatment option on polyester and acrylic felts. Treating with silicone aids the initial build up of the dust cake. Its non-blinding characteristic provides limited cake release for pressure drop consistency. Silicone treating also reduces moisture absorption. It is not advisable for food applications. Siloair: Obsolete DCE spunbond polyester compact bin vent style filter. Singeing: Singeing is the melting of surface fibers with a gas flame to reduce the tendency of dust particles to stick to the surface. It is recommended for improved dust cake release. A singed finish is a standard option for polyester felt. Slot Velocity: Linear velocity or rate of flow through a slot opening, usually measured in feet per minute. SMACNA: Sheet Metal and Air Conditioning Contractors National Association.

Donaldson Company, Inc. © 200 Dictionary-22 (5/03)

Smoke: Air suspension of particles, or aerosol, usually solids less than a micron in length or effective diameter from a combustion or sublimation source. Smokebuster: Obsolete Aercology commercial line of modular media filter system for use in office buildings, restaurants, and other public and commercial locations. Solenoid Valve: A plunger solenoid is a simple electromagnet consisting of a coil of wire, operating on the concept of electromagnetic attraction. This type of solenoid uses a steel plunger placed inside an electric coil (electromagnetic). When voltage is applied, the plunger will tend to center itself within the coil. When power is turned off, the spring returns the plunger to its off-center position. Source Capture: The capture of contaminants at the point of generation prior to escaping into the workplace environment. This can be done with local exhaust systems or engineered air pollution control systems. sp. gr.: Specific gravity. Spark Trap: A drop out box with or without water used in high spark loading applications. (See Drop Out Box.) Spotair: Obsolete DCE compact, low volume venting filter for easy venting at many points in material handling systems. Used either cartridge or bag filter media depending on the application and space constraints. Squirrel Cage: Slang term for a forward curve fan wheel. The main attributes of a forward curve fan wheel are quiet operation, non-material handling, and low space requirements. ST-1: Dust explosibility class of Kst ≤ 200 bar m/s. ST-2: Dust explosibility class 201 ≤ Kst ≤ 300 bar m/s. ST-3: Dust explosibility class of Kst ≥ 301 bar m/s. STEL: Short-term exposure limit. STP: Standard temperature and pressure. Surface Loading: The collection of contaminants on the surface or face of the filter media rather than throughout the entire thickness. This can be characterized by a a rapid rise in filter resistance. Swarf: Fine solid material such as metallic particles and abrasive fragments suspended in coolants typically in grinding applications. Grinding swarf is fine and can stay suspended in mist droplets resulting in heavier dirt loading on the filtration system. Swing Arm: A general term for the FT-500 arm in the Trunkline Products due to the arm’s ability to pivot or swing about its mounting point.

Donaldson Company, Inc. © 200 Dictionary-23 (5/03)

TBI: Torit Backward Inclined fan. (See Backward Inclined Fan Wheel.) TD: Torit-Donaldson continuous-duty, pulse-jet cartridge collector with vertically oriented cartridges and upflow airflow pattern. Available in rectangular and cylindrical (high vacuum) designs for lower airflows. TDE 9600: Obsolete Torit cartridge collector used on weld fume applications with the same configuration as the TD. Temperature, Dry Bulb: Temperature level indicated by a thermometer without any effect of moisture on the reading. Temperature, Effective: An index that combines the effect of temperature, humidity, and air movement velocity on the sensation felt by the human body. Temperature, Wet Bulb: Thermodynamic wet bulb temperature at which liquid or solid water can by evaporation bring the air to saturation adiabatically at the same temperature. Wet bulb temperature, without any qualifications, is the temperature indicated by a psychrometer, such as a sling psychrometer. Tetratex: Donaldson Company’s registered trademark for PTFE membrane that can be thermobonded to the surface of filter media using pressure and temperature. TH1500: Obsolete Torit round-bag, shaker style baghouse. Thermally Generated: Contaminants generated by thermal or heat generating processes such as ultra-fine mist and smoke from EDM operations or fumes from soldering applications. Thermally generated contaminants tend to be smaller than those mechanically generated. Thermo-Tek Filters: Donaldson Torit filter cartridges that can withstand operating temperatures up to 275 degrees F. Torit-Tek filter cartridges contain proprietary synthetic filter media and use special adhesives and gaskets to assure structural integrity and airtight sealing characteristics under elevated temperatures. Threshold Limit Values: Values for airborne toxic material concentrations that people may be exposed to for 8 h/day, usually. Throwaway Liner: A thin replaceable filter designed to protect a primary filter from loading with solids. Also a thin, spun-bonded polyester filter located on top of the primary filter in the rotating drum on Aercology Centrifugal Mist Collectors. The throwaway liner is the standard replacement filter and protects the primary filter from solid particles in the collected mist. It is replaced when 50% to 75% blocked with solids. Timer: Solid state timers are used to control the cleaning mechanism on pulse-cleaned units and on collectors with automatic shakers. On pulse-cleaned units, the timer activates solenoid valves which in turn activate diaphragm valves releasing air pulses. On shaker-cleaned unit, the timer activates the shaker motor. TJ: Obsolete Torit round-tube pulse-jet rectangular collector replaced by the PJD.

Donaldson Company, Inc. © 200 Dictionary-24 (5/03)

Torit-Tex Filters: Donaldson Torit filters that use Tetratex PTFE membrane technology to handle moist, hygroscopic and agglomerate dusts. Available in cartridge and bag configurations to extend filter life and provide high filtration efficiency. Transition: Any connecting piece of ductwork or sheet metal, which may or may not be supplied by Torit Products. Examples include a transition from a dust collector hopper discharge to a valve (called a valve transition) and a transition from a collector clean air exhaust to a HEPA filter housing. Transport Velocity: Conveying velocity for dust in a duct or pneumatic conveyor pipe, usually the same or more than the minimum duct velocity in dust collection systems. TRB: Torit Radial Blade fan. (See Radial Blade Fan Wheel.) Trough Hopper: A receptacle for delivering material from the entire outlet length of the dirty air plenum/filter section to a screw conveyor to maximize material drop out and handling. Tube Sheet: The divider between dirty and clean air plenums in a dust collector where the filters are typically attached by a cage or yoke. ULPA: Ultra low penetration air filter that is 99.999 percent efficient at collection of dust down to 0.12 micron size. Ultra-Web Filters: Donaldson Company’s proprietary filters that use nanofiber filtration technology in combination with cellulose filter media to deliver better cleaning efficiency, lower cost per cubic foot of air per minute (cfm) and reduce energy consumption through improved filtration performance. (See nanofiber filtration) UMA: The acronym for the intermittent-duty, shaker-style DCE Unimaster. Unducted Collection System: See Ambient Air Collection Systems. Unit: A stand alone DCE collector consisting of dirty and clean air plenums, including hopper, enclosed filter section, and integral fan. Valve: Any mechanical device by which the flow of liquid, gas, or loose material in bulk may be started, stopped, or regulated by a moveable part. Examples include rotary valves (airlocks) handling dust, diaphragm valves handling air, and solenoid valves handling electricity. Vapor: Gaseous form of substances. Vapors diffuse. They can be changed to a solid or liquid state by an increase in pressure or decrease in temperature. Vc: Can velocity, or velocity of the airstream while it passes between the filter elements in a dust collector can or enclosure. Vee Bag: An ASHRAE rated, disposable filter used in Aercology Modular MediaFilter systems. The filter has a series of V-shaped filter envelopes or pockets to increase filter surface area and dirt storage capacity. Velocity: Flow rate of an airstream, or other movement, usually measured in feet per minute. Velocity Pressure: See pressure, velocity.

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Vena Contracta: Formed by the convergence of the airstream just after it enters a hood or duct inlet. The area of the airstream at the vena contracta usually ranges from 70 to 100 percent of the duct area. A loss of static pressure occurs in the formation of the vena contracta, so it is desirable to use efficient hood and inlet designs. Vertical Mount: A collector mounted so airflow through the filter system is vertical. Typically inlet and outlet airflow will also be on the vertical plane. The standard mounting for a variety of source capture collection systems for wet or dry applications. Vf: Filtration velocity, or velocity of the airstream when it enters or passes through the filter media, often referred to as the air-to-cloth (A/C) or air-to-media ratio (AMR). It is important to know the units of measure used for the ratio. For example, 2:1 in English units would mean 2 cfm per ft2 of filter media. However, 2:1 in metric units would mean 2 m3/hr per m2 of media. It may be necessary to convert units. Vibration Base with Isolators: Structural channel type housed spring isolators that large fans can be mounted onto to reduce vibration effects of a fan. (See also Fan Price Sheets.) Volume: Measure of space, expressed in cubic feet or cubic meters. Walk-in Plenum: A weather protective enclosure for top bag access on baghouse units. May be considered an OSHA confined space. Weather Cowl: Weather cover on clean air discharge opening to protect from rain and snow. WeldAIR™: Obsolete portable welding Aercology cartridge collector. WeldAIR™ Pulse: Obsolete portable welding Aercology cartridge collector featuring pulse cleaning. Wind Load: Wind speed rating, in miles per hour, used to size and specify leg structures on dust collectors. For example, standard Downflo II leg structures will meet a maximum wind load of 100 mph. Each region of the world has its own basic wind speed for calculating leg structure wind loads. XE: High loft, fine fiber, fiberglass Modular MediaFilter used on the Aercology MDV-10 collector for sticky contaminants and high viscosity or dirty mists. The standard filter in the MDV-10 units. XP: Paper-like, micro-glass, box filter used in the Aercology Modular MediaFilter MDV-10 collector for clean, low viscosity oils or dust and fumes. XT: Obsolete, high capacity, higher efficiency, micro-pleat version of the above XP media. The XP is used in the Aercology Modular MediaFilter MDV-10 unit for clean, low viscosity oils or dust and fumes. The filter requires a 1” track and the clamp strip for the above XE or XP filters must be removed and relocated to the sides of the filter sealing face frame to form the track (unless ordered with the XT filter).

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Zeolite: Hydrated natural or synthesized aluminosilicates of the alkaline and alkaline earth metals. There are about 40 different natural varieties mined from mineral deposits and about 150 synthetic. They are used primarily for pet litter, animal feed, odor control, fertilizer carrier, oil absorbent, soil stabilization and water purification. They are good for filtering, adsorbing, and neutralizing and are used to control gas or vapor phase contaminants and can be used alone or with an impregnant (such as potassium permanganate).

i American Conference of Governmental Industrial Hygienists (23rd Edition). Industrial Ventilation A Manual of Recommended Practice. Columbus, OH. 1998. ii Croom, M.L. Filter Dust Collectors Design and Application. McGraw-Hill: New York. 1995. iii Merriam-Webster, Inc. (10th Edition). Merriam-Webster’s Collegiate Dictionary. Springfield, MA. 1994.

ABCDEFGHIJ-LMNOPQ-RSTU-VW-XZEnd Notes