Equipment III Glossary adsorption The adhesion of molecules to the surface of another phase. anti-solvent A compound that is miscible with the solution solvent but the desired solute is relatively non-soluble with the anti-solvent. approach The difference between a cooling tower's cold water outlet temperature and the wet bulb temperature. blowdown The process in which some of the water from a cooling tower basin is removed and make-up water is added. burner management system (BMS) A logic-controlled system that monitors the conditions of a furnace. cake The layer of solid buildup on the surface of a filter medium. catalyst a substance that alters the rate of a chemical reaction without being consumed or permanently changed chemically catalyst fouling The accumulation of carbon or impurities on the catalyst or packing. catalyst poisoning The result when contaminate chemicals bond at the surface of the catalyst but do not release. catalytic cracking A chemical reaction that uses a catalyst to break apart long hydrocarbon molecules. channeling A term used to describe a fluid following a single path due to an unequal distribution of liquid. chemical absorption The incorporation of one substance into another substance by chemical reaction. condenser A type of heat exchanger that changes a medium from its gaseous state to its liquid state, either through cooling or high pressure. conductivity A measure of how well a substance conducts electricity. conservation vent A type of vent that opens only when the pressure in a vessel reaches a set point and closes when the pressure is reduced. continuous stirred tank reactor (CSTR) A model of reactor design that assumes the reactants are well stirred in a vessel so that the concentration of reactants is consistent everywhere in the vessel. cooling tower Heat exchange device that removes heat from a liquid, usually water, and discharges it to the atmosphere. crystal A group of atoms arranged in a three dimensional, repetitive pattern. crystallization The formation of crystals from a solution. cycle of concentration (CoC) The ratio of the solids concentration in the basin water of a cooling tower compared to the concentration of the make-up water. cyclone A device that removes particles or liquid droplets from a gas stream by directing the gas in a vortex path. damper Flap or device inside ductwork that can be adjusted to control air. decanter A device that uses gravity to separate two liquids with different specific gravities. depth filtration A filtering mechanism that removes particles by trapping them in layers throughout the medium. drift Liquid water drops that are trapped in rising vapor. drift eliminator Baffles or labryth passages used to remove drift from cooling tower vapors. dry scrubbing The process of removing impurities from a gas by introducing a completely dry sorbent into the gas stream. dynamic inline mixer A continuous inline mixer with a motor and rotating shaft, which is capable of high shear mixing. emergency vent A type of vent that can relieve large amounts of gases in case of a fire or other event that can cause rapid pressure buildup emulsion A suspension of two immiscible liquids. end-of-line vent A type of vent that relieves directly to the atmosphere. evaporator A device that separates compounds from a solution by vaporizing some of the solvent to produce a more concentrated solution. extract In extraction, a solution of the solute and solvent. extraction The process of using two immiscible liquids to separate a solute from one phase into the other. fill The material in a cooling tower used to disperse water to create exposure to air. filter aid Materials added to a filter either as a pre-coat or as body feed to enhance filtration. filtrate The fluid that passes through the filtering medium. The filtrate may be a gas or a liquid. fin Plates or corrugations used on heat exchangers plates or tubes to increase surface area and heat transfer efficiency. flame arrester Device which provides flame protection for a vessel or pipe. flame impingement A term that indicates a flame is touching the refractory or tubes or is mixing with another flame. flue Ductwork that removes waste gases from a furnace. free vent An open or hooded pipe open to the atmosphere. heat exchanger A device that transfers heat from one fluid to another. high heating value (HHV) The amount of heat released by all the components in a fuel. inerting The process of creating a non-reactive (low oxygen) atmosphere by filling a vessel with an inert gas, usually nitrogen. Also known as blanketing. inhibitor A chemical compound that can cause a specific reaction to slow or stop. interface The region of separation between two immiscible liquids. low heating value (LHV) The high heating value (HHV) minus the heat required to vaporize the water formed during combustion. make-up Water added to a system to replace water which leaves the system due to evaporation, drift, or waste elimination. manway cover vent Device installed on manway openings to provide emergency relief for large volumes of vapor to the atmosphere. Maximum Allowable Working Pressure (MAWP) The maximum continuous pressure for which a vessel was designed at a given temperature. metastable zone (MSZ) The concentration of solvent and solute between saturation and super-saturation. microbe A living organism such as bacteria, algae, and fungi. miscibility The tendency for two fluids to mix. mixing valve A mixing mechanism installed inline with piping that mixes by creating turbulence and swirling. mother filtrate The liquid in the feed slurry to a filter. National Fire Protection Association (NFPA) Organization that establishes codes and standards intended to minimize the possibility and effects of fire and other risks. permeate In membrane separation, the liquid and smaller particles that passes through the membrane. phase inversion In extraction or decanting, a type of flooding where the interface can end up at the bottom of the column. physical absorption The incorporation of a substance in one state into another of a different state. pilot A small burner used to light a main burner. pipe-away vent A vent that connects to piping that relieves to a relief header or containment. plug flow model A model of reactor design that simulates adding reactants at one end of a tube. polish filtering The removal of very fine or microscopic solids. Typically the last step in liquid clarification. precoat Filter aid added to the surface of a filter medium to enhance filtration. primary nucleation The formation of new nuclei from a super-saturated solution. raffinate In extraction, the carrier solvent with a reduced concentration of the solute. rag An emulsion that is stabilized by the presence of solids. range The temperature difference in a cooling tower between the entering hot water and the exiting cooled water. reactor A vessel used to contain and control a chemical reaction. recuperator In a dryer system, a heat exchange device that recovers heat for reuse. refractory Special composite material used to line combustion equipment. relief header A system of pipes and vents that direct the released fluid to a different location. relief system System that responds to overpressure levels by allowing gases or liquid to escape to the atmosphere, a storage vessel, or a relief header. retentate In membrane separation, the feed with larger particles that does not pass through the membrane. run-away reaction The result when the heat generated by the reaction or reactions exceeds the heat that can be removed. saturation point The point of a solution where the number of solute molecules reforming is equal to the number of molecules dissolving in the solvent. scale Deposits of solids and crystals that precipitate on surfaces in contact with water. scrubber A device that removes impurities from a gas stream either by absorption or adsorption. secondary nucleation The formation of crystal nuclei from clusters broken from formed crystals. seeding In crystallization, the process of adding crystals or nuclei in solution to a super-saturated solution. Seeding is used to control the number and size of crystals formed in a crystallizer. shear Force applied to a fluid. side reaction A secondary, often unwanted, chemical reaction that can occur along with a primary reaction in a reactor. solubility The measure of how well a solute dissolves in a solvent. sparger A perforated pipe used to distribute a gas as bubbles that are broken up and dispersed by the impeller. specific gravity The ratio of the density of a substance to the density of a reference substance. static mixer A tube, or pipe, containing stationary blade-like baffles used to mix liquids inline with piping. super-saturation The concentration of solvent and solute where the solution ha