0% 0 Fuels and Combustion Quiz 1 1 / 50 A good metallurgical coke_____? Should have low fusion point of its ash Should be brittle Should have high porosity Must contain moderate quantities of ash, moisture, sulphur and volatile matters 2 / 50 A coal having high volatile matter content will _________? Give less yield of tar and gas on carbonisation None of these Burn with a small non-smoky flame Have a very high calorific value 3 / 50 ?Wobbe index? is a characteristic of___________? Liquid fuels Solid fuels Gaseous fuels Fat coals 4 / 50 Adiabatic flame temperature of a fuel is dependent on the initial temperature of_____? Fuel Air Both A. & B. Neither A. nor B. 5 / 50 A coal that softens and fuses on heating is__________? Classified Caking Carbonised Non-caking 6 / 50 ?Fat? coal means a coal having _____? Low ash content High volatile matter Non smoking tendency Low calorific value 7 / 50 ?Micum Index? of a coke is a measure of its_____? Bulk density Reactivity Hardness & strength Porosity 8 / 50 A coal having higher volatile matter content, has lower__________? Chance of catching fire during storage in open space Ignition temperature Coke oven gas yield on carbonisation Smoking tendency on burning 9 / 50 Advantages of fluidised bed combustion are ______? High heat transfer rate All A., B. & C. Reduced NOx formation in flue gas Lower furnace operating temperature 10 / 50 ?Overfire burning? in a furnace is a phenomenon characterised by the ___________? Supply of excess air Burning of carbon monoxide and other incombustibles in upper zone of furnace by supplying more air Supply of excess fuel None of these 11 / 50 (64-132) rank coal (ASTM) means a coal with 64%_____? None of these Fixed carbon and a heating value of 132 BTU/1b Fixed carbon and having a heat value of 13, 200 BTU/1b Ash and a heating value of 13, 200 BTU/1b 12 / 50 A gaseous fuel in order to develop luminosity on burning, must contain ___________? Oxygen Hydrocarbons Hydrogen Carbon monoxide 13 / 50 A good quality coal should have _____? High sulphur High ash content None of these Low fusion point of ash 14 / 50 64-132) rank coal (ASTM) means a coal with 64%_____? Fixed carbon and having a heating value around 13, 200 BTU/1b Ash and heating value around 13, 200 BTU/1b None of these Fixed carbon and heating value around 132 BTU/1b 15 / 50 A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the__________? High sulphur content in the fuel Low calorific value of the fuel Presence of large quantity of hydrogen in the fuel Lack of thorough mixing of fuel with air 16 / 50 ______ present in coal is not determined in its ultimate analysis ? Total carbon Hydrogen Fixed carbon Nitrogen 17 / 50 A good coking coal should have high _______ content? None of these Ash Moisture Sulphur & phosphorus 18 / 50 A coal with high ash content_____? Has low quantity of mineral matter Is harder and stronger Has higher calorific value Is not subjected to washing 19 / 50 A coal containing high amount of volatile matter will have___________? Low adiabatic flame temperature High fusion point of its ash Low ignition temperature Very little ash content 20 / 50 A coal with high ______ content, would ignite most easily? Oxygen Volatile matter Fixed carbon Ash 21 / 50 Air/gas ratio for complete combustion will be the highest for___________? Gobar gas Carburetted water gas Coke oven gas LPG 22 / 50 A particular coal is said to be free burning when it ___________? None of these Gives smokeless burning Burns completely Shows little or no fusing action 23 / 50 __________ is used as jet engine fuel ? LPG Diesel Petrol Kerosene 24 / 50 _____ process is meant for direct hydrogenation of coal to produce liquid fuel? Bergius Fischer-Tropsch Lurgi None of these 25 / 50 ?Fuel? can be defined as a substance which produces heat by_____? Combustion Nuclear fission Nuclear fusion All A., B. & C. 26 / 50 Actual flame temperature is always lower than the adiabatic flame temperature, because there is_________? Always loss of heat from the flame Neither A. nor B. Both A. and B. No possibility of obtaining complete combustion at high temperature 27 / 50 A certain thickness of the coal, if stored unscientifically on soft (katcha) ground having no metallic/concrete flooring gets sunked into the ground, which is termed as the ?carpet loss?. The carpet loss may be of the order of _______ cms? 20 to 40 5 to 15 1 to 2 3 to 4 28 / 50 A fuel containing carbon and carbon monoxide (but containing no hydrogen or its compounds) is burnt in pure oxygen at constant pressure. Its gross calorific value as compared to net calorific value will be__________? More Same Less Data insufficient; can?t be predicted 29 / 50 About ______ Nm3 of air will be required for the complete combustion of 2Nm3 of CO? 3 2 5 4 30 / 50 Artificial draught produced by a fan can be controlled by the_____? Variation in the pitch of the fan blades All A., B. and C. Damper Speed of the fan 31 / 50 A coal with high ash content is undesirable, as_________? It is abrasive to the coal pulveriser (i.e. ball mill) and the combustion chamber The ash retains the sulphur & phosphorus and thus affects the quality of products in metallurgical furnace apart from increasing the slag volume. Besides, it may fuse and stick to the boiler tubes thereby reducing the heat transfer The ash in molten condition gets absorbed in the pores of the refractory lining of the furnace and causes its spalling due to different co-efficient of expansion/contraction of the refractory and the ash All A., B. and C. 32 / 50 A coal containing very high percentage of durain is called _______ coal? Non-banded Splint Boghead Bright 33 / 50 A fuel with high heat release rate will__________? None of these Have high adiabatic flame temperature Require smaller combustion chamber Have high calorific value 34 / 50 Abel apparatus is used for those oils, whose flash points are ___________?F? > 120 < 120 > 280 300-600 35 / 50 A coal having higher volatile matter content will necessarily have lower______? Caking index Ash fusion temperature Ignition temperature Calorific value 36 / 50 ______ has the widest inflammability limit (explosion limit) of all the gases? Methane Hydrogen Acetylene Carbon monoxide 37 / 50 A coal gasifier operating at 20 atm. (e.g. Lurgi gasifier) as compared to one operating at atmospheric pressure (e.g. Kopper-Totzek or Winkler gasifier) will produce a gas having _______? Lower carbon dioxide content Higher methane content and thus higher calorific value None of these Higher carbon monoxide content 38 / 50 ?Fat coals? are those coals which have very high______? Fusion point of its ash Inherent moisture content Caking capacity Volatile matter content 39 / 50 A carbonaceous fuel (containing no H2 or hydrocarbons) is burnt and the resulting flue gas contains 21% CO2. It means that_____? 21% excess oxygen has been used for combustion 21% excess air has been used for combustion No excess air has been used for combustion Complete combustion of fuel has taken place 40 / 50 ______ prohibits the use of alcohols directly in petrol engines ? Low octane number High cost & availability Low calorific value Low flash point 41 / 50 A coal having high amount of volatile matter______? Would require smaller combustion chamber Ignites easily and burns with long smoky flame Produces very little of tar and gas on carbonisation All A., B. and C. 42 / 50 Ammonia content in raw coke oven gas is about ______ gm/Nm3? 1 5 100 50 43 / 50 A sample of natural gas containing 80% methane (CH4) and rest nitrogen (N2) is burnt with 20% excess air. With 80% of the combustibles producing CO2 and the remainder going to CO, the Orsat analysis in volume percent is__________? CO2 : 6.26, CO : 1.56, O2 : 3.91, H2O :15.66, N2 : 72.60 CO2 : 6.39, CO : 1.60, O2 : 3.99, H2O:25.96, N2:72.06 CO2 : 7.60, CO : 1.90, O2 : 4.75, N2 : 85.74 CO2 : 7.42, CO : 1.86, O2 : 4.64, N2:86.02 44 / 50 Anthracite coal ______? Contains more volatile matter than bituminous coal Is essentially a coking coal Burns with short, bluish, yellow-tipped flame producing very little smoke Ignites more easily than bituminous coal 45 / 50 A travelling grate stoker is meant for the efficient burning of _______ coal? Pulverised Caking High ash Non-caking 46 / 50 Anthracite can be used for_____? Blending with highly coking coal to check its swelling which helps in saving coke even walls from damage and to produce high strength coke Recarbonising steel All A., B. and C. Making carbon electrodes 47 / 50 ?Wind loss? resulting from unscientific storage of coal may be the order of about ______ percent? 14.5 10.5 7.5 2.5 48 / 50 A coal having high ratio of volatile matter to fixed carbon as compared to a coal having low ratio of volatile matter to fixed carbon __________? Is more difficult to ignite and produces a shorter flame Requires smaller combustion space and less secondary air None of these Is less liable to spontaneous combustion on storage 49 / 50 Abrasion index of blast furnace coke should be around ______ percent? 80 20 55 35 50 / 50 ______ of the coal is the basis for Seylor?s coal classification? Calorific value Ultimate analysis Proximate analysis Caking index Provide Your Information Your score is The average score is 0% LinkedIn Facebook Twitter 0% Restart quiz Send feedback Share on facebook Facebook Share on twitter Twitter Share on whatsapp WhatsApp PrevFluid Mechanics for Chemical Quiz 15 Fuels and Combustion Quiz 3Next
