GATE Chemical Engineering 2000

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    IGATE - 20011

    CHEMIC L ENGINEERING

    SEcnONA

    ONE M RKS

    QUESTION8

    2 i

    for

    M(h

    of the

    fol.lowing questions

    (I

    to 29)

    four allemativts A,

    ll , C >md

    Dare

    pro

    vi

    ded.

    lttdicate the con u t answe.oby

    writing A,

    B,

    C

    or D,

    as

    -uppoopo

    iule

    ,

    against

    the too

    -r

    esponding

    question

    number in the

    box

    in the

    answer

    book.

    (

    Ma

    ks: I

    x.

    29 = 19)

    1\

    pa

    or

    oil';11

    dice

    is

    roll

    ed

    Simul tan

    eously

    1lte pro

    ba

    bllity that the sum of lhe

    n

    um

    bers from dice equals ~ l x is

    a

    b

    c.

    d

    I

    6

    7

    36

    5

    36

    1

    12

    2. For an e1en fu

    nct

    ion

    a f (x)dx'= ll

    '

    b.

    J(( x)d

    =I

    '

    c.

    J .+ =-J- x)

    d j (x) =

    f -

    x)

    3

    l'he

    lmegraung facror for d1e

    differential

    equation. (ces' ~ ) e l y -t J' = tan x. IS

    dx

    a.

    l l l l l

    b.

    cos2

    .1:

    c>

    '

    d

    s' 2x

    In n binary liquid so lution of

    cornponeniS

    A

    and

    B. of

    co

    mponent-A etme thai benzene is insoluble in wa ter

    1lte normal

    boi

    ling points

    of

    bcmcue

    aJJd

    ~ > a t e r

    arc

    80.1c and 1ooc. resuecti1

    el

    y

    AI a pressure of 1-atm, dtc boiling point of

    a of e n z ~ n c and wntor is

    a c

    b

    le

    ss lhan su.1c

    c. wo

    c

    d,

    greater ihml

    80 tc

    but less t

    han

    t

    c

    On

    a P -

    V diagram

    of nn

    i

    dea

    l

    ~ ; n s

    suppose a rc1

    ers

    i

    bl

    e adiabatic line

    uner,;ects

    a reversible

    tsot

    herm

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    ().

    11

    .

    13.

    14

    .

    In

    o lull) lurbulenl flo11 (Rt: 10

    3

    1 in n

    pipe

    of cJiamcl

    er for a c

    ons

    tam pressun.

    grndicnL Ulc i l u n < ~ lay

    .W

    now

    lh l

    plate, the

    t

    l1 t

    () (i

    )t) vorics

    3$;

    J ,

    R""

    b JRc

    where ,; the boandniJ' layer tht10knes

    and x is Ute distance fronl the leading edge

    in

    the

    dirc:ctlu

    n.of 11ow.

    Por laminnr

    flow

    of

    nshcnr-lbfnning liquid

    in a pipe. if lhe volumetric

    ilo rnte

    doubled. the pressure gradient

    will

    in.,.e.sc

    by Q

    fcto.r or

    a.

    b. < 2

    c. > 2

    d. 112

    The Gtushof number i l defined as che r.c io

    I)

    I

    :c buO)'OI\ey IH inertial rurcc:s,

    h.

    buo

    ynt\O) lu v

    i>Wu

    l i n ' C c

    c:

    .. lneni:.ltd

    on

    tile cryshtl size.

    '

    lbc 'P timc

    nllllly dctenninod ovemll

    or

    der tO

    r

    t1Ha

    re:u

    tio

    n A

    ~

    B

    _.

    C t- D l ;

    lwo.11en the

    a.

    rca

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    1

    J4

    .

    25.

    E

    80 JIMOl

    r

    1

    c q C, : F.t 110

    k.J ,o

    tho dcslf\.-d

    pt1JJucl

    R A high"r

    :>declivity or

    R

    will be l1Cn

    1

    CVL':

    tn

    a CSTR

    b lugh temperature m a

    CS

    '

    J'R

    c. lo11 lcmp\lratu

    rc

    In a

    PFR.

    d.

    higb

    temperature

    m nPJ7R

    ln

    solid cawtysed

    reac.lt

    W1S

    tlte dtl'Fusm

    nal

    e J T ~ c t s nre

    more

    llkelv 10 affect

    the O\'emll

    mtc of reacuoo l'or

    IL fast reactions '" catolysL of

    smal

    l f'lWC

    dia meter

    b fnsl reDctitlns 111 t ~ l y s t s . of Drg pore

    d i a m e t ~

    c.

    T i l ~

    llllltJl i

    tude

    raliu ui a pme cnpac

    i

    l)

    '

    proc:e:

    m v ~ 1 ' l ' < l prupurtionu.l

    (n the

    frcqu"ncy

    d llle ump

    litude

    rnuo of u

    ~

    lim"

    del

    a) S)

    ~ t e r n

    incrca l< s

    11 ith freq u

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    3l

    35

    d rr

    rhe nverse

    of

    the IJlatrJ.,

    [I

    a. Doe1;

    not exist

    b LS [

    c.

    . [

    o

    5

    .s]

    IS

    --{)

    .5 -0.5

    d

    ~

    ]

    5 05

    - I

    I]

    -I

    Tbe

    complex co n llgale

    of' -

    1

    -

    ts

    I I

    1

    a,

    1-1

    b. (I 1)

    e

    0.

    5(1

    - 1)

    d. Ul

    \lie

    Ursl

    quadrant

    or

    compl

    ex

    plane

    lite genera l so

    .l

    ut1on of

    tl

    v

    d

    1

    y

    - - + +J =O

    S

    < -

    and the pressure drop ac

    ro

    ss

    the

    bed

    ts I0 kPa, tl1

    en

    tbe density o.f panicles 1s

    L

    2.5

    74 kg/tn

    b. J5 14 kg/m

    3

    c.

    4000

    kg/rn

    3

    d

    4350

    kgtm'

    A

    free jei

    of

    waicr of cross-secuooaJ aren

    0.02 m

    1

    and velocity of 20 m/s stnkes d

    plate and

    d1en

    tlm>JS in plane parallel to

    U1e

    plate as shown 10 the figure below. 1l1e

    hQtizontal cumpqni O\ of the force: on

    U1e

    suppoti

    1s

    ll 200

    b

    -l

    OON

    c, :woo N

    d 40

    00

    N

    A s1ee l sphere of rndtus () I m at 400 K rs

    unmersed tn

    an oil Qt 39Q K. If the centre

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    o

    the sphere rcoche

    350

    K

    in

    20 n u n ~ l

    e s .

    how long will

    it

    take f

    or

    a 0.05 m rndin

    s f

    ee

    l sphere to teach the sante tempet'oture

    (at

    Ut

    e coult" ) under

    identi

    ca

    l

    co

    odilioru?

    t \ . ~ J o t m e lltat lh,. u.)nv..owc hl llt

    tran5fer

    cl1ell'icient

    iR

    in finitely lllrgt.

    s. 5 min

    h. LO tttin

    c. 10Jttlo

    d,

    40

    111 in

    41 , A

    uompo

    5Jte

    J'Wt

    waU o

    fu ona

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    Heat eapacities, CI'A

    = Cn =

    l00

    kJ

    /

    km o1

    K (may be assmned to be independent of

    tempernture.)

    49 'T'he t .)'

    I lhe point (1, 2,

    3)

    I ltirecHon llom

    (1 , 2, 3)to l, - l, -3)

    5 1. Futd whether or not tht> vcct"rs (1,1,2),

    (1

    .

    2, J) ru1d (0, 3, -3) are linearly

    independent

    52 [ndnstrial sraie metlumol

    ClU1

    he

    E00UOed

    according to tlte reacdon

    CO g)+2H

    1

    g)C

    C pR(g)

    Fo

    r Ui9 fffiction

    .c.o

    4

    uu

    = -

    U484

    kl. 1

    -

    ru

    t equi.toolril .

    mi..'dllJ

    e Df 00 llld liz is fed

    l > a retc

    t.or

    rr

    ru

    rJtlnne4 at..

    4

    00

    . K a11

    d 10

    bar,

    detemune,

    tl

    te fraction of CO

    lhat is

    conv.erted

    into

    CHPH

    a1

    egui.b'brium.

    Ao."Uln

    e

    il tat

    ilte

    reactio11

    mixture .behaves

    like 9:11 ideal gas.

    53 .

    b

    a binruy mixture the aotiVll;y coefficienl

    rt

    of compon011t I, in the cutirc range of

    ro

    nrpo>11ion,

    is

    g1 ven by

    .R

    ln

    r

    1

    =lr]+

    &;

    wltere R. A 1llld B are constants. Denve

    lhe e . > , p . r e s ~ o n for

    Ute

    activity coefficient

    ofCOJtlponenl

    2.

    54 A

    Jt

    ydrocarbou oil (visce>slly 0.025 Pa s

    and density 900 leline, i t

    . r e q u i r e d ~ use a Q4 m

    diam

    eter, 10 km

    55

    1.) ors

    long prpo

    to

    pump

    ihe

    oil

    at tl

    tc same.

    volnmeiric .flow rate as

    in

    Ute prev

    tous

    case. Estintatethc pressutEf drop f01 llte O

    . i

    m

    di

    amet

    er

    pipe.

    Asawne

    hotiJ

    pipejt to be

    ltydtodynmnicaJJy smoofll and in tlte range

    of opet'iding eonffirians ,

    l.he

    Fanning

    Diction factor is i v e n ~

    / =

    Q.079Re-OJ'

    A rree

    Jet

    ofwater ls produ ced usi ng a 75

    mm

    diarr

    tet,er u,

    1ZZJe

    ui.mehed to

    >L

    200 fllm

    diameter pipe, m; -.b.owu .in the .figure.. f

    the

    average vclooi ty of'water

    at

    plane B is

    3.8 mJ., calculate tlw velocity f w ~ at

    point A

    i.it

    tlte fr

    oo

    jet Neglect friction

    l.:,gses in llte

    1lll:(21E' and

    pipe

    T

    Obtain

    the eqnalion

    1pr

    fltc.

    qclinc givc11

    th

    aL

    lhe.

    OJ

    Jt'f>l

    l:htg

    limsare.

    /. D ., , . cfi

    y -

    .lllJTm

    ls used

    to

    extract

    a solute from rutaqtteous

    stream (F t Sing an o.q;anic .

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    7,

    58.

    59,

    1\ir at

    1 n is

    blown past

    the bulb

    of a

    mercuty m

    o m ~

    111e

    bu

    tb is

    covered

    with a wick. l11e wick is Immersed

    in rut

    orgamc liqwd (molecular wcight

    =

    58).

    'The reading of tho them10meter is 7.6 "

    C.

    At Otis temperature,

    the

    vapour pressureof

    01e

    liqul

    d

    c 5

    k

    Pa

    .

    fi

    ud

    Oc air

    t.emperttture;

    given tha

    t

    t

    he

    r

    ah t

    of

    the

    tru.qsfer

    c.oet1'icents

    to the o>ass ITansfer

    coeflicie

    nt

    (psychromeu

    ic

    mtio)

    ts

    2 kJ

    lll

    K and the latent heat

    of

    vapourisat

    io

    n

    of

    the

    liqui

    d is 360

    kJ

    ikg.

    Ass

    u

    me ih

    m the

    arr,

    wh

    ich ts

    blown

    .

    is fre

    e

    fro

    m

    the

    org nic v pour

    A piau

    1s

    designed

    to

    produ

    ce. 1.2

    I

    k

    i lvte of

    an a

    gro< 10. The followitlf\

    oost datn

    are

    available;

    Raw

    m

    at

    cnals:

    0. 9/Kg product

    Labour and uulino

    s.

    c.tc.:

    Rs

    0.27/

    iql:

    product

    prlce u

    fpr

    odu cf: Rs 10/Kg

    O

    ilc

    r

    costs

    (O

    n pet ycur inc ludin

    H,

    mamlertance. tnsurace.

    etc

    ,

    @W% or

    lixed capital.

    Indirect

    costs of d m i t S U m i o t ~ R&D.

    marketing.

    c(c

    .

    @20%

    f

    sal

    e

    pnx;

    c

    eds

    .

    'n 1e plant wi

    ll

    be tit

    ll

    ) depreciated ovet u

    period

    of

    5

    years us ing the stmlslu line

    tueO

    od.. l l

    te

    ra

    te

    of

    t

    it

    cmue tax is 10%.

    C

    uku

    l

    at

    a,

    rl1e net

    pro

    it at th

    e end

    of

    firs

    t yenr

    ll, dte payout period.

    l he

    r

    e;-ponse

    of a

    tlicnuoeouplc can be

    .

    mode lled as u

    first

    order process to

    changes

    tn

    the temperarure

    of

    the

    60

    61

    .

    63

    .

    7on

    environment.

    If

    such a thcnnocouple

    31

    25C is

    inuuersed s

    udden

    ly in a

    fluid

    at

    80C

    ana

    held tht'l'C . it Is fOlDld that

    Ot

    ec

    thcnn lCOup le reading (in C) re:whc

    :>

    63.

    2%of

    the final steady sta te value in 41l

    seoo11ds. Find the time coostaut of tlte

    Olimll()COUille:

    A

    tcedi,Hk control

    loop

    wit

    h n

    propottio

    na

    l cont

    ro ll

    er has an open loop

    trlU $ler fuuctiou

    where rime i$

    ill

    miuuteS; Obtain

    Ute

    crussover liequency wtd U e ultinm lc

    controlh:r gail).

    Given

    th

    e

    (Q II

    owing bloc

    .

    tll lgrnm,

    . EA

    llllSS the

    trnnsii:r Jimcoon (Y/X\ ns

    a ratio ur

    po

    lynoultals in s.

    b. Ca lculare tlte

    off.o;e

    r ' C

    du

    e io o un

    it

    ~ : h _ a n g e n lhc

    rcrcren e Sl

    g_n

    al

    \S

    et-point) R.

    1'he el

    ement

    a

    ry.

    second

    -or

    der. ltqutd

    phase r"nction D is

    conducccd

    .n

    an.

    tSI,l

    therma1

    plug

    fl

    ow

    r e ~ c t o r

    or

    I m

    1

    capacity. The inlet ' 'ol ume trfc flllW rate is

    10

    m' tb and C.-.

    1

    = C

    1

    ' 2 lunolltu' At

    th

    ese

    c o n d t i o n s con

    version o f

    is 5 0 ~ - o

    Now

    . if a stirred tank reactor of 2

    rn

    3

    capacity is installed in series, upstream

    of

    lhe plug 0Qw reactor,

    lb

    cu

    wilaL

    con

    version tmu

    bt: e

    xpec

    te

    d_

    h1 the

    nd w

    system Qf reactors?

    The f o l l o w

    ~ liqu

    id pbnse t

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    64,

    65.

    66.

    Each of tlto .

    products men

    uoned 111 the left

    hand column requires one

    or

    Jnore of the

    reactants mel\fio

    ned

    In the right-hand

    column, March

    the products

    wi1h

    the

    approprinte r e a c m n t { s ~

    (I) Phthalic anhydride

    (U

    1

    Cu111ene

    tAl Benzene

    ( l) N.aphthale}le

    (C)

    Carbon

    monoXIde

    (D) Phenol

    (E) Propylene

    (F) Atr

    (G) EtltyJ benzene

    (H)

    Hydrogen

    SyttU,.lSis gas

    rs 11 n iurc

    of

    n.

    CO

    and H,

    b. a n d H,

    n II_, and CO

    d COt and H,

    The ttction A ZB

    +

    C takes place

    ru

    .a

    caw

    l

    yt

    ic

    reuttor

    (see

    diagnun

    be

    low), The

    reactor effluent

    IS

    sent to u separator

    The

    overall conversiOn of A is 95% 11te

    product

    stream from the separator consists

    Qf B. ( and 0.5o/o of A enterrng the

    separator, while

    rh

    e recycle Sll'eam

    consistS of lbc rema1nder of the unrcactcd

    A aud 1% of B entcriug tlt separaJor.

    Calculate he

    a, swgle

    P8

    couvorsooo of A

    ill

    tl1e

    reactor

    b molar

    ratoo

    of

    recycle

    to

    feed

    :. I L l _ _ . . . _

    -

    ..

    .....,_

    lfl

    67 "'he 11

    1S1de surface

    temperature

    ofa pipe

    (ra

    dms = 0. I m) IS 400 K

    The

    ptpe

    ts

    los tog hear to atmosphere,

    wbJch

    IS

    at

    300

    K

    The

    ftllll .beat transfer CQefficieut

    IS 10

    68.

    >C)

    K k

    W/m

    1

    K.. To reduce

    tltc ra

    te of heat loss,

    lbe

    pipe is 1nsula t

    ed

    by a 50mm thick

    a y ~

    ofnsbestos (k = 0.5

    Wlm K)

    .

    Calculate Ut

    percentage reduction m the rnte of heat

    loss.

    In a 1-1 counter flow she

    ll

    and tube hear

    exchanger, a process stream (Cr = 4.2

    kJ kg

    K)

    is cooloo

    limn

    450

    to

    J5(l

    us

    ing '""ter (

    c .

    =

    4.2 kJ/kg J.:) a1

    JOO

    K

    The

    proCes

    .stream flows on the she

    ll

    -side

    ar a

    rare

    of I kg/s and the warer on the

    tuhes1de at a,rJte of 5

    4;

    /s, f heatlmnsfer

    coefficients

    on

    the shel l

    nnd rube

    s1des are

    1000 Wtm K

    and

    1500 Wtm

    K,

    respectively, d