8/17/2019 Coal Mill and Milling System

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Coal Mill and Milling System :

1. The function of the classier is

a. To control the nes of the coal leaving the pulveriserb. To remove foreign material from the coalc. To mix primary air with coal for dryingd. To increase the coal velocity in PF pipe

2. Drying capacity of medium speed mills area. 1!b. 1"!c. 2"!d. 2!

#. $ase capacity of mills are in general %atised ata. "&'(b. )"&'(c. 1""&'(d. *+&'(

*. (n ,-P /)# $owl bill the bowl P0D isa. /)b. +#c. 1)#d. )#

. hich of the following coal mill is most ine3cient under part load conditiona. Drum 4illb. $owl 4illc. $iter 4illd. $all 4ill

). 4ill performance can be improved bya. (ncreasing air temp. of primary air fanb. (ncreasing neness of the millc. Pre crushing of coal to smaller si5ed. (ncreasing spring tension on roller assembly

/. The separator body liners servea. To redirect large coal particles bac6 to bowl for regrindingb. To separate the pulveriser body from the gear housingc. To separate the large coal particles from the smaller onesd. To increase velocity of PF particles into PF pipes

7. 0eiling air Fan is used fora. The milling systemb. %ealing ash hopperc. %ealing air heaterd. 8ll of the above

+. -e9ect removal in bowl mill is done bya. a separator body linerb. %eparator bottom linerc. %craperouslyd. :one of the above