Glossary

Anionic--a negatively charged ion in water solution

Bag Filter—a pressure filter where fabric bags are installed inside a cylindrical housing (pressure vessel) and the filtered liquid is pumped through the bag walls. Liquid flow is from the inside to the outside of the bag - dirt is trapped inside the bag. These pressure vessels must be ASME (American Society of Manufacturing Engineers) coded.

Biocide--a chemical agent used to kill microbiological organisms (bacteria or fungi) in MRF. Biocides are registered by the EPA under Federal Insecticide Fungicide and Rodenticide Act (FIFRA) and are known officially as antimicrobial pesticides.

Blind Off—to plug or coat media pores to the point MRF will not flow through.

Cartridge Filter—a pressure filter where paper or fabric cartridges are installed inside a cylindrical housing (pressure vessel) and the filtered liquid is pumped through the cartridge walls. Liquid flow is usually from the outside of the cartridge wall through to the inside core - dirt is deposited on the OD of the cartridge. These pressure vessels must be ASME coded.

Central System—a large MRF system for a transfer line or group of related machines using a common MRF and usually machining the same metal.

Centrifugal Separator--a mechanical separator that uses centrifugal force to remove aerosol particles from an air stream or uses centrifugal force to separate liquids of different density, e.g., separate tramp oil from water based MRF.

Chip Conveyor--a mechanical system to move metal debris from the metal removal process.

Clarifier—equipment used to remove contaminant from MRF.

Clarity—degree to which MRF is free of contaminant. Clarity should include weight or volume of particulate in parts per million (PPM). A description of particle count by size may also be determined. A description or specification of the test method is also required.

Close Capture Enclosure—a device mounted near a contaminant source for the purpose of containing or removing air contaminants. By design it will have a high entrainment velocity and lower air volume requirement. This is an effective method of enclosure.

Coalescence Separator--a separator that collects fine particles and coalesces them into a continuous phase that can drain from the collector.

Compatibility--"Compatibility" of MRF means that the fluid does not chemically react with other materials in the metal removal process.

Contaminants—substances contained in in-use metal removal fluids that are not part of the original fluid formulation. These can include abrasive particles, tramp oils, cleaners, dirt, metal particles, dissolved metals, hard water salts, bacteria, fungi, and microbiological byproducts.

Cyclone Filter--a type of centrifugal separator

Decant System—system to separate light floating liquid (tramp oil) from a heavier liquid (water-soluble MRF).

Denier--as used here, the diameter of the fiber used in a disposable filter medium.

Depth Filtration--filtering through a bed or cake of dirt (particulate) removed from the MRF as it is established on the septum.

Dipstick—slide prepared with appropriate growth media, dipped into MRF, and incubated to measure microbial growth in MRFs. Relatively inexpensive, easy to use, and available commercially.

Disposable Medium—usually a roll of non-woven fabric through which the dirty MRF is passed. This porous fabric filters the contaminant from the MRF.

Dissolved Air Floatation System—a decant system with a method of introducing compressed air into the MRF air. The dissolved air bubbling up through the MRF picks up fines and improves the clarity in the submicron range.

Drag Conveyor--a type of mechanical chip conveyor, often consists of two roller chains with cross bars to move the metal debris.

Drag Tank—MRF tank with flight conveyor to scrape out chips that have settled. Dirty liquid flows into tank and overflows a relatively clear liquid to the next stage in the filtration process.

DOP Filter--a high efficiency air filter that has been tested using the dioctylphthalate (DOP) challenge test.

Electrostatic Separator--an air cleaner that charges aerosol particles and then removes them from the airstream by passing the charged particles between high voltage plates to cause electrical migration to the surface.

Employee Exposure—the exposure to metal removal fluids and contaminants that would occur without protection provided by any respirator or other personal protective equipment that is in use.

Emulsion—a mixture of liquids that do not dissolve in each other to form a true solution, but have droplets of one liquid dispersed throughout the other. For MRF it is generally an oil and water mix.

Emulsifier--a substance added to soluble oil MRF to aid in forming an emulsion in the fluid (see above.O

Enclosure—a mechanical device that creates a separation or barrier between the process and the worker's environment. Enclosures may be designed as close capture, total enclosure or tunnel enclosures.

Endotoxin--a component of the cell wall of gram-negative bacteria.

Filter—a porous medium (disposable media, wedge-wire or mesh screen) through which liquid is passed to separate and trap particles held in suspension.

Filter Cake--the buildup of particles on the surface of filter medium. Filter cake can improve the removal performance of a filter, but it also leads to increased pressure drop and reduced fluid flow.

Flight Conveyor—conveyor consisting of a motorized drive, (2) sections of heavy duty chain, and a series of bars or sections of angle iron (flights) bolted between the chains at regular intervals. As the conveyor moves, the flights are dragged across the bottom of the tank carrying accumulated contaminant out for disposal.

Flow-Through Conveyor—similar to a drag tank, having a flight conveyor, except that the bottom is made of wedge-wire panels (.020 to .040 inch slot width) and relatively clear liquid flows through the wedge-wire. Used primarily on aluminum machining jobs where aluminum chips float and would not settle out in a drag tank. Flow-through conveyors are designed to pass 75 to 100 GPM per square foot of wedge-wire panel.

Head Pressure—discharge pressure of a pump in feet of liquid being pumped.

HEAD x SG = psi discharge pressure

2.31

HEPA Filter--High efficiency particulate air filter. Available in different performance classifications ranging from 95 to 99.99% efficiency for 0.3 um DOP aerosol

Hinge Pan Conveyor—conveyor consisting of a motorized drive, (2) sections of heavy-duty chain, and a series of pans with pusher bars mounted between the chains. Hinge pans are used to remove bundles of stringy chips. Chips accumulate on the hinge pan and are carried out for disposal while the MRF overflows into the filter tank.

Hood—a hood is a generic term for a device designed to capture contaminated air and conduct it into an exhaust duct system. The term may include enclosures, canopy hoods, push-pull hoods, down draft hoods, side draft hoods or others.

Impaction Separator--a mechanical device that uses the inertial properties of entrained aerosol particles to separate them from an airstream and collect them on an "impaction surface."

Impingement Separator--similar to the impaction separator except that the airstream is directed toward a liquid surface instead of a solid surface.

Index—in automatic media filters (vacuum and flat bed), to advance the media to remove a dirty and plugged section. In automatic wedge-wire drum and wedge-wire septum filters, to scrape the wedge-wire and remove a portion of the dirt load that forms the filter cake.

In-Use MRF--metal removal fluid that is being used and continually recycled for lubrication, cooling, chip transport, and corrosion protection of a metal removal operation. These fluids are distinguished from "as received" metal removal fluids by the presence of contaminants from the metal removal process, the machine tool, and biological growth in water based fluids.

Magnetic Conveyor--a chip or swarf conveyor for ferrous metals that uses magnets below a chip plate to move the metal debris without direct contact of the moving conveyor with the waste material.

Media (Filter)—that part of the filter upon which the contaminant is actually trapped as the fluid passes through. Usually disposable media, permanent belt, wedge-wire, etc.

Medical Management--the use of medical information to help control the health risk posed by a contaminant in the workplace. The risk management decisions may be directed toward the entire workforce or they may be made for a single worker who is not able to safely work in an area due to a temporary or permanent medical condition.

Medical Monitoring--the collection of medical information to screen for health problems that may be related to work in a specific work environment. The focus is on early detection of health problems for the individual employee.

Medical Surveillance--is the systematic examination of medical monitoring data to determine if there are unusual patterns of health problems in the workplace. Statistical techniques may be used in larger workplaces to improve this analysis.

Metal Removal Fluid (MRF)—a fluid applied to a tool and workpiece while cutting or removing metal. This fluid may be water- or oil-based. Its principal functions are to cool the tool/workpiece interface, to provide lubrication, and to flush chips or contaminants generated in the metal cutting or removal process.

Metal Removal Process—a manufacturing process that removes metal to produce a finished part.

Metal Working Fluids—a generic term to describe four categories of fluids (straight oils, soluble oils, semi-synthetic and synthetic) that facilitate a wide variety of operations involving the working or modification of metals. Metal removal fluids are used in machining and grinding and honing operations. Metal forming fluids are used in stamping, forging, drawing, coining, rolling, piercing, cold heading and wire/bar/rod drawing operations. Metal protecting fluids are used primarily for fingerprint displacing and indoor/outdoor storage. Metal treating fluids are used primarily for metal quenching operations. Drawing and forming fluids are similar or identical in composition to MRFs but are used in an entirely different way.

Micrometer (Micron)—one millionth of a meter

1 m m = 1 meter ; 1 millimeter = 0.000039 In.

1,000,000 1,000 (39 millionths of an inch)

Mist—fine liquid droplets suspended in or falling through a moving or stationary gas atmosphere.

MRF System—usually includes a clarifier, electrical controls, pumps and a trench return for chips and spent MRF. May also include water make-up, chiller for temperature control, tramp oil skimmer, variable speed pump control, etc.

Neat Oil—as it comes from the drum; not diluted. Usually refers to soluble oil before mixing with water to form soluble oil and water MRF mixtures. Sometimes used to describe straight mineral oil.

Nominal Rating—rating for roll media, filter cartridges and filter bags. Nominal rating is mean flow pore size of media: half the flow is through pores smaller than the nominal rating and half the flow is through pores greater than the nominal rating. Not an explicit specification.

Nonionic--a water soluble material, e.g., emulsifier, that does not form charged molecules in solution. Not anionic of cationic.

Occupational Exposure Guideline--a guide for use in evaluating worker exposures to particular workplace contaminants, especially where there is a lack of definitive data to establish a safe exposure level.

Particulate Matter—small dirt particles suspended in MRF or microscopic particles suspended in air.

Plenum Duct System--a portion of a ventilation system in which a section of the duct is larger in cross sectional area resulting in a much lower transport velocity. The advantage of such a system is that ducts can be connected or removed from the plenum section without causing dramatic changes in the overall airflow balance of the system.

Pocket Filter

Positive Filtration

PPM—parts per million; must state test used and whether by weight or by volume.

Pressure Filter—a filter where the filtered liquid is pumped under pressure through the media. Examples are automatic flat bed filters, cartridge and bag filters.

Reverse Osmosis--the use of semi-permeable membranes and pressure to overcome osmotic pressure and produce high purity water.

Roller Filter Conveyor--a system to use roll filter media with a mechanical conveyor over a flat-bed filter to clean MRF.

Semi-synthetic MRF—a water-based (reducible) MRF composed of both water-soluble components and emulsifiable components. It may or may not include performance-enhancing additives, and generally contains 5 to 30% (by volume) of oil. In mixed form semi-synthetic MRF may contain 5% or less of oil.

Separator

Soluble Oil MRF—a water-based (reducible) MRF composed of an emulsion of oil (or oil-like material) in water. It may or may not include performance-enhancing additives.

Spiked Belt Conveyor

Straight Oil—usually refers to an oil used as an MRF. Could be a mineral seal oil (40 to 50 SSU) used for honing, a light oil (90 to 100 SSU) used for aluminum machining (valve bodies) or a heavy oil with high-pressure additives used for broaching (250-450 SSU). Contains no water and is not mixed with water in normal conditions.

Surfactant--surface active agent such as an emulsifier or detergent that lowers the surface tension of water.

Swarf—fine particles of metal, graphite and carbide that result from grinding operations.

Synthetic MRF—a water-based (reducible) MRF composed of a true solution of water-soluble organic and/or inorganic components. It may or may not include performance-enhancing additives.

TAN

Tapered Main Duct System--an engineered exhaust ventilation duct system that is balanced by design rather than dampers or blast gates. The diameter of the duct work increases as additional ventilation air is added to the system

TBN

Total Enclosure—a box or housing around the machine or process. The housing is not intended to be airtight. Openings are limited to the minimum required to allow for part entry/egress, maintenance or utility access.

Tramp Oil—petroleum contaminants of metal removal fluid that come from hydraulic oil, gear oil, way oil, and other lubricants.

Tramp Oil Skimmer—a device for removing floating tramp oil. Common types are endless tube, disc, belt, and decant systems. All tramp oil removal systems require regular maintenance - systems remove fines as well as floating tramp oil and tend to plug up. Must be installed in a still or quiescent part of the filter dirty tank.

Tunnel Enclosure—a continuous total enclosure over two or more connected work stations or machining processes. The design principles are similar to those applied for total enclosure.

Turnover Time or Retention Time—related to particulate settling rate. The more viscous the MRF, the lower the settling rate; thus the turnover time should be increased by increasing the system tank volume.

Flow rate gal x turnover time min = tank vol gal

min

Turnover time min = tank vol gal

flow rate gal

min

Soluble oil and water systems generally have 3 to 5 min. turnover time, while light oil systems have 7 to 10 min. turnover time.

Ultrafiltration

Vacuum Filter—a filter where a vacuum is created on one side of the media, usually by means of the pump suction. Atmospheric pressure then pushes the dirty liquid through the media.

Water-miscible--designed to be diluted with water

Wedge-Wire Drum—wedge-wire drums are made by spirally wrapping wedge wire over a mandrel with longitudinal support rods. The wedge wire is automatically resistance welded to the support rods forming a drum. As the wire is wrapped, a precise dimension is maintained between each wrap to form precision slots. Slots are usually in .007 to .010 range for vacuum filtration applications.

Wedge-Wire—wire drawn to a wedge shape - used primarily for strainer and filter applications. Standard materials are the 300 series stainless steels.

Wet Metal Removal Fluid Environment—the workplace environment in which wet metal removal operations occur.