Mechanical Engineering FUELS & COMBUSTION Terms and Definitions :-
ACCELERATOR – Device for rapid control of the speed of an engine, for quick opening and closing of the throttle which regulates the quantity of air fuel mixture into the engine cylinder.
ACHESON GRAPHITE – That made from coke in an electric furnace.
ACTIVATED CARBON – A highly absorbent form of carbon used to remove odours and toxic substances from gaseous emissions or to remove dissolved organic matter from waste water.
ADDITIVE – A substance added to fuel or oil or grease which improves the properties of the same.
ADIABATIC FLAME TEMPERATURE – The maximum possible temperature attained by the products of reaction, when the reaction goes to completion and all the heat released is used to heat up the products.
AERATION TEST BURNER – Apparatus by which the combustion characteristics of commercial gases can be correlated and calibrated.
AEROSOL – A particle of solid or liquid matter that can remain suspended in the air because of its small size. Particulates under 1 micron in diameter are called aerosols.
AFTER BOIL – Boiling of the fuel in the carburettor or coolant in the engine immediately after the engine is stopped.
AFTER BURNING – In an internal combustion engine, the persistence of the combustion process beyond the period proper to the working cycle, i.e., into the expansion period.
AFTER BURNER – In an automobile engine, a type of exhaust manifold that burns the hydrocarbon and carbon monoxide remaining in the exhaust gas.
AIR ASPIRATOR SYSTEM – An air injection system using a valve opened and closed by pulses in the exhaust system.
AIR FUEL MIXTURE – Air and fuel travelling to the combustion chamber after being mixed by the carburettor.
AIR FUEL RATIO – Ratio (by weight) between air and fuel that makes up engine fuel mixture.
AIR INJECTION SYSTEM – A system which injects air into the exhaust manifold or thermal reactor so that the combustion of the carbon monoxide and unburned hydrocarbons in the exhaust can be completed.
AIR MASS METERING – In some fuel injection systems, fuel metering is controlled primarily by engine speed and the amount of air actually entering the engine.
AIR POLLUTION – Contamination of earth’s atmosphere by various natural and manmade pollutants such as smoke, gases, dust etc.
ALCOHOL – Volatile liquid fuel consisting wholly or partly, of alcohol, able to withstand high compression ratios without detonation.
ANTHRACITE COALS – Slow burning coals which yield very little ash, moisture and less than 10 per cent volatiles, generally used in closed stoves.
ANILINE POINT – The lowest temperature at which an oil is completely miscible with an equal volume of aniline.
ANTIBACKFIRE VALVE – Valve used in air injection reaction exhaust emission control system to prevent backfiring during the period immediately following sudden declaration.
ANTIKNOCK – In engine fuels, that property which opposes knocking i.e., auto ignition.
ANTIKNOCK COMPOUND – An additive put into gasoline to suppress knocking or detonation e.g., Tetra ethyl lead.
ANTIPERCOLATOR – Device for venting vapours from main discharge
tube, or well, of a carburettor.
APIEZON OILS – The residue of almost zero vapour pressure left by vacuum
distillation of petroleum products.
API GRAVITY – The American Petroleum Institute (API) has established
the formula for calculating the specific gravity of a fuel or oil as Degree
API= ((141.5/specific gravity at 60/60 degree F)–131.5). The symbol
60/60 degree F is interpreted as the ratio of the weight of a given volume
of oil at 60 degree F to the weight of the same volume of water at 60
ASH – An inorganic non-combustible residue obtained by combustion of
an oil or fuel in the presence of air.
ASH AND SLAG – Impurities that do not burn and usually troublesome
elements in coal fired boilers.
ASH FREE BASIS – When fuels are delivered on an ash free basis, it means
that the percentage of the ash has been deducted and the other
constituents have their percentages recalculated on 100 per cent total
without the ash.
ATMOSPHERIC GAS BURNER SYSTEM – A natural draught burner
injector, in which the momentum of a gas stream projected from an
orifice into the injector throat inspirates from the atmosphere a part of
the air required for combustion.
ATOMIZATION – The spraying of a liquid through a nozzle so that the
liquid is broken into a very fine mist.
ATOMIZER – A nozzle through which oil fuel is sprayed into the combustion
chamber of an oil engine or boiler furnace. It breaks up the fuel into a
fine mist so as to ensure good dispersion and combustion.
UTOIGNITION – The self-ignition or spontaneous combustion of a fuel
when introduced into the heated charge in the cylinder of a compression
AUTOMATIC CHOKE – A carburettor choke device (valve) that
automatically positions itself in accordance with the carburettor needs
or engine temperature.
BACKFIRE (exhaust system) – Passage of unburned air fuel mixture into
the exhaust system where it is ignited by some hot spot and causes a
BALANCED DRAFT – A boiler using both forced draft fan and induced
draft fan, can be regulated and balanced in the amount of air and flue
gases handled so that the furnace pressure is almost atmospheric.
BAGASSE – A fuel produced as a by product of the abstraction of juice
from sugar cane. The dried cane (fibrous residue) is usually fed into a
specially designed furnance by means of overfeed stokers.
BENCH – The name applied to a complete plant for the manufacture of
coal gas. Also called RETORT BENCH.
BENZOL – Crude benzene, used as a motor spirit, generally mixed with
petrol, and valued for its antiknock properties.
BIOGAS – Obtained by fermentation in the sewage disposal system, or by fermentation of cattle waste, farm waste etc.
BIOSPHERE – The portion of earth and its atmosphere that can support life.
BLAST FURNANCE GAS – A gas of low calorific value, a by product of iron smelting due to burning of coke in the furnace with limited air, used for preheating the blast, for steam raising etc. It may contain up to 30% carbon monoxide.
BLAST MAIN – The main blast air pipe supplying air to a furnace.
BLOW BY – Leakage of unburned air fuel mixture and some burned gases past the piston rings into the crankcase during the compression and
BLOW TORCH EFFECT – In gas or oil burning furnaces, when the flame impinges on any surface, such as a tube or refractory wall, that surface is burned as by a blow torch. This is a combustion condition to be avoided as destructive to the surface.
BLUE WATER GAS – A mixture of approximately equal proportions of carbon monoxide and hydrogen made by passing steam over incandescent coke in special generators.
BOILING POINT – The temperature at which a liquid begins to boil.
BOMB CALORIEMETER – An apparatus used for determining the calorific values of fuels. The bomb consists of a thick walled steel vessel in which a weighed quantity of fuel is ignited in an atmosphere of compressed oxygen. The bomb is immersed in a known volume of water; from the rise of temperature of water the calorific value is calculated.
BOTTLED GAS – LPG (liquefied petroleum gas) compressed into strong metal containers. Gas when confined in tank, under pressure, is in the liquid form.
BRIQUETS – Coherent masses of uniform size made by the application of pressure to any powdery material placed in a suitable mould with or without a binder.
BUTANE – A hydrocarbon gas formed synthetically, by the action of zinc or ethyl iodide. Petroleum gas, that is liquid, when under pressure. Often used as engine fuel in trucks.
CALORIE – The amount of heat required to raise one gram of water through 1°C i.e., from 17 to 18°C. Calorie is unit of heat.
CALORIFIC INTENSITY – The maximum flame temperature attained when the fuel is burnt.
CALORIFIC VALVE – The heat value of a fuel, expressed in either BTU per pound or CHU per pound or kilocalories/kg. The amount of heat produced by burning unit weight of fuel.
CALORIEMETER – Measuring instrument used to determine the amount of heat produced when a substance is burned, also friction and chemical change produce heat.
CARBON – One of the non-metallic elements constituting fuel and lubricating oil.
CARBON DEPOSIT – A black, hard or soft deposit left on engine parts by the combustion of fuel. Carbon forms on pistons, rings, plugs, valve heads etc., inhibiting their action.
CARBONDIOXIDE – A colourless, odourless gas which results when hydrocarbon or carbon is burned completely.
CARBONIZE – Building up of carbon on objects such as spark plug, piston head etc., of an engine.
CARBON MONOXIDE – A colourless, odourless, tasteless, poisonous gas found in engine exhaust. Formed when carbon or hydrocarbons are burned incompletely.
CARBURETED WATER GAS – An artificial gas formed by passing steam through a bed of glowing coke and thereafter enriching the gas so formed with petroleum vapour.
CATALYTIC CONVERTER – A muffler like device for use in an exhaust system that converts harmful gases in the exhaust into harmless gases by promoting a chemical reaction between a catalyst and the pollutants.
CETANE NUMBER – Rating of ignition quality or performance characteristic of diesel fuel. A high cetane number fuel ignites more easily at lower temperature than a low cetane number fuel.
CHARCOAL – Product obtained by heating wood out of contact with air.
CHARCOAL CANISTER – A container filled with activated charcoal used to trap gasoline vapour from the fuel tank and carburettor while the engine is off.
CHEMICAL CHANGE – A change which alters the composition of the molecules of a substance producing new substances with new properties.
CLOUD POINT – The temperature of a liquid (fuel or lubricant) at which a haze or a cloud first appears in a sample of oil, when cooled in a prescribed manner.
COAL – A firm, brittle, sedimentary, combustible rock derived from vegetable debris which has undergone a complex series of chemical and physical changes during the course of many million years.
COAL GAS – A fuel formed by the distillation of coal, usually in a retort or a coke oven.
COEFFICIENT OF HAZE – A measurement of visibility interference in the atmosphere.
COKE – A fused cellular porous structure that remains after the free moisture and the major portion of the volatile matter have been distilled from coal.
CAKING COALS – Coals that become soft under the usual furnace temperatures and merge into undesirable masses of coke. The coal that becomes soft, melts and solidifies into a more or less solid mass which further hardens on heating out of contact with air.
COLLOIDAL FUEL – A mixture of fuel oil and powdered coal.
COMBUSTION – Process involved during quick burning. Release of chemical energy into heat energy occurs during combustion.
COMBUSTION EFFICIENCY – is the ratio of the (heat) energy liberated to that which could be liberated under ideal conditions. Quantity of CO2 and H2O in the exhaust indicate energy liberated, whereas the quantity of H2, CO and CH₄ indicate unliberated energy.
CRACKING – The process of breaking of heavy molecules into lighter hydrocarbons.
COMPRESSION IGNITION – Ignition of fuel through the heat of compression as in a diesel engine.
COMPRESSED NATURAL GAS – usually assumes the form of compressed methane, and is suitable for obtaining ultra low emissions from combustion engines. Soot production is virtually zero.
COMPOUND – A combination of two or more ingredients mixed together.
CONSTANT PRESSURE COMBUSTION – Combustion which occurs without a change in pressure. In an engine, this is obtained by the slower rate of burning than with constant volume combustion.
CRUDE OIL – Petroleum as it comes from the oil well (raw or refined state). It forms the basis of gasoline, engine oil, diesel oil, kerosene etc.
DETONATION – An uncontrolled instantaneous second explosion in a spark ignition engine, after the spark occurs, with excessively rapid burning of a portion of the compressed air fuel mixture (end charge almost exploding) resulting in a spark knock, or pinging noise.
DIESEL INDEX – A rating of fuel according to its ignition qualities. The higher the diesel index number, the better the ignition quality of the fuel.
DIMETHYLETHER – is a synthetic product with a high cetane number, producing little soot and reduced nitrogen oxide when combusted in diesel engines.
DISTILLATION – Heating a liquid, and then catching and condensing the vapours given off by the heating process.
DRAFT – The differential pressure in a furnace to ensure the flow of gases out of the furnace and flow of air into the furnace.
DUST – Fine grain particles light enough to be suspended in air.
ECOSPHERE – The layer of earth and troposphere inhabited by or suitable for existence of living organisms.
EFFLUENT – Waste material discharged into the environment, treated or untreated.
EGR SYSTEM – Exhaust gas recirculation system. It sends part of the exhaust gas back through the engine by way of the carburettor or intake manifold, which reduces the amount of NOx that is formed by an engine.
ELECTOSTATIC PRECIPITATOR – An air pollution control device in which solid or liquid particulates in a gas stream are charged as they pass through an electric field and precipitated on a collection surface.
ELUTRIATION – A process of separating lighter particles from heavier particles by washing solid waste with a slowly moving upward stream of fluid that carried the lighter particles with it.
EMISSION CONTROLS – A term applied to any device or modification added onto, or designed into a motor vehicle for the purpose of controlling a source of air pollution emission.
ETHANOL – Ethyl alcohol produced by east fermentation of a variety of carbohydrates such as saccharin (sugar canes, sugar beets, molasses and fruit juices), starch (cereals and potatoes) or cellulose (wood waste, sulphite liquor).
ETHYL GASOLINE – Gasoline to which ethyl fluid has been added to improve its resistance to knocking. Slows down burning rate and thereby creates a smooth pressure curve that will allow the gasoline to be used in high compression engines.
EVAPORATIVE EMISSION CONTROL SYSTEM – A system which prevents the escape of gasoline vapours from the fuel tank or carburettor float bowl to the atmosphere while the engine is off.
The vapours are stored in a canister, or in the crankcase until the engine is started.
EXCESS AIR – Air present in the cylinder over and above that which is theoretically necessary to burn the fuel.
EXHAUST GAS – The products of combustion coming out from an internal combustion engine.
EXHAUST GAS ANALYZER – A device for sampling the exhaust gas from an engine to determine the amounts of pollutants in the exhaust gas. This determines combustion efficiency.
FLAME DETECTOR – A device that monitors the flame in a furnace that is burning oil, gas, or pulverized coal fuel. Failure of the flame results in a signal and the actuation of various protective controls on the fuel feed to prevent an explosion.
FLAME SAFEGUARD SYSTEM – An arrangement of flame detection system, interlocks and relays, which will sense the presence of a proper flame in a furnace and cause fuel to be shut off to the furnace if a hazardous (improper flame or combustion) condition develops.
FLASH POINT – It is the temperature at which the quantities of vapour which a combustible fuel emits into the atmosphere are sufficient to allow a spark to ignite the vapour air mixture above the fluid.
FLUE DUST – Solid particles (smaller than 100 microns) carried in the products of combustion.
FLUE GAS ANALYZER – Device which measures the percentages of volume of carbondioxide, carbon monoxide and oxygen in the flue gas of a boiler.
FLY ASH – Combustion ash so fine that is carried up and into the atmosphere by the movement of the flue gases. It can become neighbourhood nuisance by settling on surfaces in the area after it loses its velocity.
FOG – Suspended liquid particles formed by condensation of vapour.
FORCED DRAFT FAN – The fan that pushes or forces air into the furnace, usually at a pressure higher than atmospheric pressure.
FRACTIONAL DISTILLATION – A process of separation on the molecular basis or on the basis of the boiling point of various fractions.
FREE LIQUIDS – Liquids which readily separate from the solid portion of a waste under ambient temperature and pressure.
FUEL – The substance that is burned to produce heat and create motion in an engine or heat substances. Any combustible substance.
FUEL CALORIEMETER – A meter (also called oxygen bomb) to determine the heating value of 1 kg of fuel by burning a sample of the fuel under controlled conditions.
FUGITIVE DUST – Particulate matter composed of soil which is uncontaminated by pollutants resulting from industrial activity. Fugitive dust may include emissions from haul roads, wind erosion of exposed soil surfaces and soil storage piles, and other activities in which soil is either removed, stored, transported, and redistributed, also solid air borne particulate matter emitted from any source other than through a stack.
FUME – Any kind of noxious vapour arising from a process of combustion or chemical reactions. Includes smoke, odorous materials, metallic dust.
FUME AFTERBURNERS – Units designed to consume combustible fumes by means of a direct fired combustion chamber through which the fumes must pass on their way to the stack and the atmosphere.
FURNACE EXPLOSION – The ignition and almost instantaneous explosion of highly inflammable gas, vapour or dust accumulated in a boiler setting.
GAS – A state of matter, neither solid nor liquid which has neither definite shape nor definite volume. Air is a mixture of several gases.
GASOLINE – A liquid blend of hydrocarbons, obtained from petroleum crude oil, used as the fuel for most automobile SI engines.
GRINDABILITY – A descriptive term of a characteristic of coal that is important to pulverized coal systems.
HEATING VALUE OF A FUEL – The heat liberated by the complete and rapid burning of a fuel per unit weight or volume of the fuel. Also called calorific value of the fuel.
HIGHER HEAT VALUE – A standard recommended by the ASME, the higher heat value of a fuel includes the heat value of the hydrogen in the fuel. The heating value indicated by a fuel calorimeter.
HIGH TEST GASOLINE – A term referring to the octane rating of a fuel. A high test fuel has a high octane rating.
HOGGED FUEL – Wood that has been chipped and shredded, usually by a machine called a “hog”.
HYDROCARBON – A compound made of elements of hydrogen and carbon atoms. Gasoline, diesel oil are blends of different hydrocarbons refined from crude oil.
IGNITION TEMPERATURE – The temperature at which the heat that is generated by the reaction between air and fuel vapour, is faster than that is lost to the surroundings, and combustion thus becomes self propelling. Below this point, the gas air mixture will not burn freely.
IGNITION QUALITY OF DIESELS – is indicated by cetane number. It is the percentage of cetane by volume, in a mixture of cetane (C16 H34) and alpha methyl naphthalene which will exhibit the same ignition characteristic of the fuel under test when tested in a standard engine, under a set of standard test conditions.
INCINERATION – The controlled process in which the combustible solid, liquid or gaseous wastes are burned and changed into non-combustible gases.
INCINERATOR – Any furnace used in the process of burning waste for the primary purpose of reducing the volume of the waste by removing combustible matter.
INDUCED DRAFT FAN – The fan that draws the gases out of the furnace by creating a partial vacuum on the suction side of the fan.
INFRARED GAS ANALYZER – A non-dispersive infrared gas analyzer used to measure very small quantities of the pollutants contained in the exhaust gas.
KEROSENE – This petroleum product is a liquid fuel having an average latent heat of vaporization of 105-110 BTU lb and the specific heat of 0.50, sometimes called COAL OIL.
KNOCK (engine) – In an engine, a rapping or hammering noise resulting from excessively rapid burning of the compressed air fuel charge.
LIGNITE – A coal of high moisture content and low calorific value, generally less than 8300 BTU/lb. May require predrying before being used as a fuel.
LIQUID ASH REMOVAL SYSTEM – An arrangement of piping by which molten ash is removed continuously or intermittently, as desired, from the bottom of a furnace. The operating medium is usually compressed air with pneumatic controls.
LIQUEFIED PETROLEUM GAS (LPG) – A gas fuel that is stored in liquid form and is converted into gas as it leaves the storage tank by a pressure regulator that steps down the storage pressure on the liquid at the tank outlet and thereby permits the liquid to assume its normal gaseous state at the existing temperature and reduced pressure.
LONG FLAME BURNER – An oil or gas burner in which the mixture of fuel and air is delayed long enough to produce a long flame from the burner nozzle. Can be a source of trouble if the flame impinges on either refractory or tube surfaces.
LOWER HEATING VALUE – Net heat liberated per kg of fuel after the heat necessary to vaporize and superheat the steam formed from the hydrogen (and from the fuel) has been liberated.
LOW LEAD FUEL – Gasoline which is low in tetraethyl lead (approximately 0.5 gm per gallon).
MECHANICAL DRAFT – Draft produced artificially by means of forced or induced draft fans.
METHANOL – Methyl alcohol produced from coal by its liquifaction, by pyrolysis, or by its reaction with high pressure hydrogen.
NATURAL DRAFT – Draft produced by a chimney, by a column of hot gases existing inside the chimney.
NATURAL GAS – Gas obtained from petroleum mines.
NOx – Oxides of nitrogen, a by-product of combustion within the combustion chamber at high temperature and under heavy load. A basic air pollutant.
NOx CONTROL – Any type of device, or system, used to reduce the amount of NOx produced by an engine.
NO LEAD FUEL – Gasoline to which there has been no intentional addition of lead compounds.
OCTANE RATING – The measure of antiknock property of gasoline. The higher the octane rating, (OCTANE NUMBER), the more resistant the gasoline is to knocking or detonation and better the quality: Higher compression engines require higher octane gas.
OCTANE NUMBER OF A FUEL – is the percentage by volume of isooctane in a mixture of iso-octane (C8 H18) and n-heptane (C7 H16) which will exhibit the same antiknock characteristic of the fuel under test when tested in a standard CFR variable compression ratio engine, under a set of standard test conditions.
OIL BURNER – Any device wherein oil fuel is vaporized or so called atomized and mixed with air in proper proportion for combustion.
PARTICULATES – Small particles of lead and other substances occurring as solid matter in the exhaust gas.
PEAT – A substance of vegetable origin always found more or less saturated with water in swamps and bogs.
PETROLEUM – Crude oil as it comes out of the ground, which consists of 83-87 percent carbon, and 10-14 percent hydrogen, plus traces of oxygen, nitrogen and sulphur. From the crude oil, gasoline, diesel, lubricating oil and other products are refined.
PHOTOCHEMICAL SMOG – The result of sunlight reacting with hydrocarbons and nitrogen oxides in the atmosphere.
PING – The sound resulting from sudden auto ignition of the air-fuel charge in a SI engine combustion chamber. Characteristic sound of detonation.
POLLUTANTS – Any gas or substance in the exhaust gases from the engine or that evaporates from the fuel tank or carburettor. These gases or substances add to the pollution of our atmosphere.
POLLUTION – The presence of matter or energy whose nature, location or quantity produces undesirable environmental effects.
POSITIVE CRANKCASE VENTILATION – PCV system-A crankcase ventilating system which produces the circulation of air through the crankcase, thus clearing it of water vapour, unburned hydrocarbons, and blow by, the air passes into the intake system of the engine and hence into the combustion chambers where they are burnt.
POT TYPE BURNER – It is a hot plate burner in which the fuel oil drops into a hot plate and vaporizes.
POUR POINT OF FUEL – is the temperature at which crystals begin to appear and the fuel flow will be interrupted, as the fuel is being cooled.
PREI-GNITION – Ignition of air fuel mixture in the SI engine cylinder (by any means) before the (ignition) spark occurs at the spark plug terminals.
PRIMARY AIR – The air mixed with the fuel at or in the burner. It ensures instant combustion as the fuel enters the furnace.
PRIMARY POLLUTANT – A pollutant emitted directly from a polluting source.
PROPANE – A type of LPG that is liquid below –42°C at atmospheric pressure.
PULSATION – A panting of the flames in a furnace, indicating cyclic and rapid changes in the pressure in the furnace.
PURGE – The evacuation of air or any other designated gas from the duct line, pipe line, container or furnace. Purging may be done in some instances simply by the use of a fan or blower, in others by driving out the air or gas by means of an inert gas, such as nitrogen, under high pressure.
RADIOACTIVE – Substances that emit rays either naturally or as a result of scientific manipulation.
REFUSE – A term generally used for all solid waste materials.
RETORT – A trough or channel built into an underfeed stoker through which the stoker ram pushes green coal into the fire. The coal enters the fire from below, hence the name “underfeed”.
ROTARY BURNER – One in which the oil entering at the center of a rotary cup is whirled around very rapidly until the oil is thrown away from the cup. By centrifugal force it mixes with air and ignites.
SAFETY CONTROLS – Devices that guard against (1) overpressure leading to explosions from the water side or steam side, (2) overheating of metal parts, possibly also leading to explosion in a fired boiler, (3) fire side explosions (furnace explosions) due to uncontrolled combustible mixtures on the firing side.
SECONDARY AIR – Air introduced into a furnace above and around the flames as may be necessary to promote combustion. This air is in addition to the primary air which enters either as a mixture with fuel or as blast underneath a stoker.
SHREDDER– A machine used to break up waste materials into smaller pieces by cutting or tearing.
SCRUBBER – A device that uses a liquid spray to remove aerosol and gaseous pollutants from an air stream.
SLACK – A coal of fine size, often screenings, and maximum size is not likely to exceed 62.5 mm.
SLAG TAP FURNACE – A furnace for burning pulverized fuel in which the ash puddles in the bottom of the furnace in a molten state and is removed periodically or continuously, depending on the design of the system, while still in the molten condition.
SMOG – A term coined from smoke and fog. This is applied to the fog like layer that hangs over many areas under certain atmospheric conditions. Smog is compounded from smoke, moisture and numerous chemicals which are produced by combustion and from numerous natural and industrial processes.
SPECIFIC GRAVITY – A measure of the weight per unit volume of a liquid as compared with the weight of an equal volume of water.
SURFACE IGNITION – Ignition of air fuel mixture in the combustion chamber produced by hot metal surfaces or heated particles of carbon.
SYNTHETIC FUELS – Fuels such as ethanol and butanol derived from coal, and hydrogen from water.
TETRA ETHYL LEAD – A chemical put into engine fuel which increases octane rating, or reduces knock tendency. Also called ethyl and tel.
TORCH – Combustible material on a metal rod, such as oil soaked rags, used to light up oil and gas burners. The torch is extinguished by being plunged into a prepared receptacle.
TUYERES – Castings appearing as components of underfeed stokers and designed to admit air to the green coal moving through the retorts.
VAPOURIZATION – To change a liquid into a vapour, often by the addition of heat.
VAPOURIZING BURNER – A burner in which the fuel oil is vaporized by heating in a retort. It may be a mixing or non mixing type.
VAPOUR LOCK – A condition in the fuel system in which gasoline has vaporized and turned to bubbles in the fuel line or fuel pump, so that the fuel delivery to the carburettor of a SI engine is prevented or retarded.
VOLATILITY – refers to the ease with which a liquid vaporizes. A liquid which vaporizes at a relatively low temperature has a high volatility. This liquid is said to be highly volatile.
WIND BOX – A plenum from which air is supplied to a stoker or to gas or oil burners.