McGraw-Hill Dictionary of Engineering Second Edition

downdraft carburetorthat conducts gases downward to a device that draft loss [MECH ENG] A decrease in the staticremoves undesirable substances. [MECH pressure of a gas in a furnace or boiler due toENG] A tube in a boiler waterwall system flow resistance. { draft lȯs }wherein the fluid flows downward. draftsman [ENG] An individual skilled in draft-{ dau˙ nkəmər } ing, especially of machinery and structures.downdraft carburetor [MECH ENG] A carbure- { drafsmən }tor in which the fuel is fed into a downward draft tube [MECH ENG] The piping system for acurrent of air. { dau˙ ndraft kärbərādər } reaction-type hydraulic turbine that allows thedown-feed system [MECH ENG] In a heating or turbine to be set safely above tail water and yetcooling system, a piping arrangement in which utilize the full head of the site from head racethe fluid is circulated through supply mains that to tail race. { draf tüb }are located above the levels of the units they drag [ENG] 1. A tool fashioned from sheet steelserve. { dau˙ n fēd sistəm } and having a toothed edge along the long dimendownholeequipment See drill fittings. { dau˙ n sion; used to level and scratch plaster to producehōl i¦kwipmənt } a key for the next coat of plaster. Also knownDowns cell [CHEM ENG] A brick-lined steel ves- as comb. 2. A tool consisting of a steel platesel with four graphite anodes projecting upward with a finely serrated edge; dragged over thefrom the bottom, with cathodes in the form of surface to dress stone. { drag }steel cylinders concentric with the anodes, condragbit See bit drag. { drag bit }taining an electrolyte which is 40% sodium chlodrag-bodyflowmeter [ENG] Device to meterride (NaCl) and 60% calcium chloride (CaCl 2 )atliquid flow; measures the net force parallel to590C; used to make sodium. { dau˙ nz sel }the direction of flow; the resulting pressure difdownspout[BUILD] A vertical pipe that leadsference is used to solve flow equations. { dragwater from a roof drain or gutter down to thebädē flōmēdər }ground or a cistern. Also known as downcomer;drag chain [ENG] 1. A chain dragged along theleader. { dau˙ nspau˙ t}ground from a motor vehicle chassis to preventDown’s process [CHEM ENG] A method for protheaccumulation of static electricity. 2. A chainducing sodium and chlorine from sodium chloforcoupling rail cars. { drag chān }ride; potassium chloride and fluoride are addeddrag-chain conveyor [MECHto the sodium chloride to reduce the meltingENG] A conveyorpoint; the fused mixture is electrolyzed, with soalongthe bottom of a hard-faced concrete or castin which the open links of a chain drag materialdium forming at the cathode and chlorine at theanode. { dau˙ nz präsəs }iron trough. Also known as dragline conveyor.downstream{ drag chān kənvāər }[CHEM ENG] Portion of a productdrag classifier [MECHstream that has already passed through the syscontainingtransverse rakes, used to separateENG] A continuous belttem; that portion located after a specific processunit. { dau˙ nstrēm }coarse sand from fine; the belt moves up throughdowntime [IND ENG] The lost production time an inclined trough, and fast-settling sands areduring which a piece of equipment is not op- dragged along by the rakes. { drag klasəerating correctly due to a breakdown, maindragconveyor See flight conveyor. { dragfīər }tenance, necessities, or power failure.{ dau˙ ntīm }kənvāər }dr See dram.drag-cup generator [ENG] A type of tachometerdrachm See dram. { dram }which uses eddy currents and functions in condraftAlso spelled draught. [CIV ENG] A line trol systems; it consists of two stationary wind-of a traverse survey. [ENG] 1. In molds, the ings, positioned so as to have zero coupling, anddegree of taper on a side wall or the angle of a nonmagnetic metal cup, which is revolved byclearance present to facilitate removal of cured the source whose speed is to be measured; oneor hardened parts from a mold. 2. The area of of the windings is used for excitation, inducinga water discharge opening. { draft }eddy currents in the rotating cup. Also knowndraft gage [ENG] 1. A modified U-tube manomərādər}as drag-cup tachometer. { drag kəp jeneter used to measure draft of low gas heads,such as draft pressure in a furnace, or small drag-cup tachometer See drag-cup generator.differential pressures, for example, less than 2 { drag kəp təkämədər }inches (5 centimeters) of water. 2. A hydrostatic drag cut [ENG] A drill hole pattern for breakingdepth indicator, installed in the side of a vessel out rock, in which angled holes are drilled alongbelow the light load line, to indicate amount of a floor toward a parting, or on a free face andsubmergence. { draft gāj }then broken by other holes drilled into them.draft hood [ENG] A device used to facilitate the { drag kət }escape of combustion products from the comfusiondrag factor [CHEM ENG] Ratio of hindered dif-bustion chamber of an appliance, to prevent arate to unhindered rate through a swollenbackdraft in the combustion chamber, and to dialysis membrane. Also known as Faxen dragneutralize the effect of stack action of the chinney factor; hindrance factor. { drag faktər }or gas vent on the efficient operation of the appliance.dragline [MECH ENG] An excavator operated by{ draft hu˙ d } pulling a bucket on ropes towards the jibfrom172