Answer / bharat

temperature inside heat-exchanger changes exponentially so
taking average would give erroneous results. and LMTD is
calculated by considering a small elemental area of heat
exchanger so it gives more accurate temperature difference.

Answer / awkash

Because temperature change in heat exchanger is not linear
in nature so we can not take airthmatic mean here,
physically you can think in the manner like if we inlet
temp. of a pipe is 80 and outlet temp. is 40 then u cannot
say that temp in middle will be 60.
thats why for accurte measurement we take lmtd.

Answer / abina

in heatexchanger temperature changes from point to point along the length so we are calculating Lmtd. ..Bt avg temperature dosnt gv correct value

Answer / anil

LMTD value it gives the correct average temperature without any errors compare to average temperature

Question 84 - In Mendelian genetics, yellow (Y) is dominant to green (y) and round (R) is dominant to wrinkled (r). (a) What is the probability P of Rr x Rr producing wrinkled seeds? (b) What is the probability P of Yy x yy producing green seeds? (c) What is the probability that RRYy x RrYy would produce RrYy?

1 Answers  

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What is the meaning – strain? In a distillation column, if a metal block 10 cm on a side is deformed so that it becomes 9 cm long due to cooling effect, what is the strain involved in percentage?

1 Answers  

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At what temperature does water have maximum density?

0 Answers  

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X is strong but has a very low density (1% of traditional earth materials.) and hence light weight. It is a recyclable material. The compression behaviour of X is strain rate dependent. Higher strain rates result in higher initial modulus and higher compression strength. It can also withstand unlimited number of cycling loading provided the repetitive loads are kept below 80% of the compressive strength. The internal structure of the material includes air-traps which make it poor heat conductor. X is non- biodegradable and chemically inert in both soil and water. Most acids and their water solutions do not attack it; however strong oxidizing acids do. Solvents which attack X include esters, ketones, ethers, aromatic and aliphatic hydrocarbons and their emulsions, among others. It does not support bacterial/fungal growth as well .It also has significant acoustic properties and effectively reduces the transmission of airborne sound. X is combustible and should not be exposed to open flame or other ignition sources. Combustion products are carbon monoxide, carbon dioxide, water and soot. Long-term exposure to sunlight causes yellowing and a slight embrittlement of the surface due to ultraviolet light. X is able to withstand the rigours of temperature cycling, assuring long-term performance.

0 Answers   Ford,

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Which chemical is used as antiscalent in RO water treatement plant?

3 Answers   Dalkia, Power Plant,

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For a heat exchanger, will the overall heat transfer coefficient increase along with an increase in lmtd (log mean temperature difference) around the unit?

0 Answers  

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What is a cstr and what are its basic assumptions?

0 Answers  

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What is a common failure mechanism for above ground atmospheric storage tanks?

0 Answers  

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Chemical Engineering Material Balance - Three hundred gallons of a mixture containing 75.0 wt % ethanol and 25 wt % water (mixture specific gravity = 0.877) and a quantity of a 40.0 wt % ethanol - 60 wt % water mixture (specific gravity = 0.952) are blended to produce a mixture containing 60.0 wt % ethanol. The specific gravity of a substance is the ratio of density of a substance compared to the density of water. The symbol of weight percent is wt %. (a) Estimate the specific gravity of the 60 % mixture by assuming that y = mx c where y is wt % ethanol, x is mixture specific gravity. Values for m and c are constants. (b) Determine the required volume of the 40 % mixture.

1 Answers  

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Explain the procedure to estimate the friction factor involved in heat exchanger tubes?

0 Answers  

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MASS TRANSFER - EXAMPLE 4.3 : According to Adolf Eugen Fick (1829 - 1901) : rate of diffusion v increases with less wall thickness t, increased area A and decreased molecular weight of a fluid M. The diffusion constant D decreased with increasing M. (a) By assuming v, t, dP, A, M and D changes proportionally of each other, find the equation of v as a function of t, dP, A and D. (b) The ratio of self diffusion constant D, at T = 273 K and P = 0.1 MPa, for gases B and C are 1.604 : 0.155. If only 2 gases exist in such a system : hydrogen and nitrogen, find the type of gas for B and C with reference to their molecular weights M. (c) By using the equation of kinetic energy 0.5 MV = constant where V = square of v, find the ratio of V for B and V for C, or V(B) / V(C), as a function of M(B) and M(C), where M(B) is molecular weight of B and M(C) the molecular weight of C : Graham's Law of Diffusion.

1 Answers  

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can hydrogen vent to atm openly from cylinder

1 Answers   Deepak Fertilisers,

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