Answer / nk

the DILUTION STEAM ADDING IN THERMAL CRACKING TO DECREACE THE VAP.PRESSURE OF THE HYDROCARBON....and it also helps in decreasing the rate of coke formation.....

Answer / eugene

Thermal crackers to produce cracked gasoline from heavy gas
oils in petroleum refineries have largely gone out of
existence and been replaced by fluid catalytic crackers and
hydrocrackers.

However, when they were used back in the 1930's and 1940's,
steam was always injected into the process tubes of the
fired heaters that raised the temperature of the gas oils
to the point where they cracked into smaller molecules ...
and the purpose of the steam was to inhibit the rate of
coking in the heater's process tubes so that the heaters
could stay online continuously for some months.

Today's delayed coking units in petroleum refineries are
designed to produce and lay down saleable coke in very
large vertical drums. In those delayed cokers, steam is
again used in the feed heaters to inhibit and delay the
coking from occuring until the heated, vaporized feed
reaches the large vertical coke drums.

Question 86 - (a) Male with genotype GGmm and phenotype gray wingless mates with female with genotype ggMM and phenotype black winged in fruit flies. G is dominant to g in color. M is dominant to m in wing shape. If the actual distribution of the second generation of the fruit flies was as follow : 890 gray wingless, 900 black winged, 115 gray winged, 95 black wingless, calculate the recombination frequency betwen the two genes and distance in recombination units. Let 1 map unit = 1 % recombination. (b) A DNA molecule has 180 base pairs and 20 % adenine. How many cytosine nucleotides are present in this molecule of DNA?

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Explain some of the consequences of an undersized kettle type reboiler?

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How can you separate hydrogen peroxide into hydrogen and oxygen?

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what is isochronus and droop speed?

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Explain what are the advantages of using gear pumps?

0 Answers  

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What is chemicals?

1 Answers   Thirumalai Chemicals,

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why we make urea prills , why we do not make crystals of urea,

1 Answers   IFFCO,

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BIOPROCESS ENGINEERING - EXAMPLE 14.1 : In differential centrifugation of cells with diameter D in centimeter, the square of D is given by D x D = [18n ln (RF / RI) ] / [ (RP - RFF) Wt ] where n is the fluid viscosity (poise), RF is the final radius of rotation (cm), RI is the initial radius of rotation (cm), RP is cell density (g / ml), RFF is the fluid density (g/ml), W the square for the rotational velocity in (radians / s) (radians / s), t is the time required to sediment from RI to RF (s). Derive an equation for W as a function for D, n, RF, RI, RP, RFF and t, with the stated units above, in radian & degree.

1 Answers  

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For a Vernier scale of representative fraction (RF) = 1 / 25, calculate the length of the scale for the reading up to 4 metres.

1 Answers  

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For a centrifugal pump if the pump is running and we close the discharge valve what is the effect

11 Answers   Asian Paints, NFTDC, Reliance,

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Explain how does a tank-blanketing valve operate?

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Question 45 - According to Raoult’s law for ideal liquid, x (PSAT) = yP where x is mole fraction of component in liquid, y is mole fraction of component in vapor, P is overall pressure and PSAT is saturation pressure. A liquid with 60 mole % component 1 and 40 mole % component 2 is flashed to 1210 kPa. The saturation pressure for component 1 is ln (PSAT) = 15 - 3010 / (T + 250) and for component 2 is ln (PSAT) = 14 - 2700 / (T + 205) where PSAT is in kPa and T is in degree Celsius. By assuming the liquid is ideal, calculate (a) the fraction of the effluent that is liquid; (b) the compositions of the liquid and vapor phases. The outlet T is 150 degree Celsius.

1 Answers  

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