Answer / sangilisaravanan

FIN TUBES INCREASES THE SURFACE AREA OF HEATING.
SO FOR THE REQUIRED QUANTITY OF HEAT TRANSFER THE EXCHANGER
MAY BE DESIGNED SMALL IN COMPARED WITH FINLESS TUBE
EXCHANGER

Answer / s.shanmugam

Fin tubes are usually used for cooling.As we see in
automobile engines constructed with fins.

Answer / anshuman

it depends on the kind of liquid to be heated and steam
requirment if high heat transfer is required with low
cosumpsion of steam we can use fin tubes

Answer / jagadesh

it is not required to heat up liquid in fin tubes by steam
because liuid has to pass trhough tube side. so if
temperature difference is more steam will undergoes
condensation and will lead high pressure drop and less heat
transfer.

Answer / dp

It depends on the htc values on the shell side. If HTC on
the shell side is higher than the tube side adding tubes
wont make much difference in terms of total heat transfer.
If the HTC value on the tube side is higher than the shell
side, adding fins will enhance the total heat transfer. For
suppose if steam is flowing on the tube side and its phase
changes during the process its good to provide fins over the
tubes. If it is other way adding fins wont make much
difference except increasing cost of the exchanger.

Answer / ahmedcool

FINS ARE USED TO INCREASE SURFACE AREA,IS LIKELY TO
TRANSFER HEAT FROM HOTTER BODY TO COLDER BODY.FINS ARE NOT
REQUIRED IN CASE OF STEAM HEATING.

Answer / amol deshpande

Yes, fin tubes are necessary. Fin tubes increases the heat surface area and reduces the thickness of shell wall required.

How can you estimate the efficiency of a pump?

0 Answers  

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MY generator water cooler inlet line height - 11 mtr inlet water line height - 7 mtr water come into the line from overhead tank, O/H tank height - 20 mtr the first tapping in the inlet line is 2" line which down to 4 mtr level plateform., second tapping in inlet water line goes to a pump 6" line installed at 4 mtr level plateform, pump capacity 200m3/hr, head- 30 mtr, hp-40. the outlet of pump of 6" water line connected to a header of 6 mtr long of 6" line, on this header the six tapping are connected, 4 nos. 3" line goes to 11 mtr height water cooler the pressure of the line is 0.15 to 0.25 kg/cm2, 2" and 4" pipe line connected to a cooler at 4 mtrlevel plateform. my question is, at 11 mtr height level the quantity of water and flow is not sufficient for my cooler, the temp. of cooler is rises much more. you are requested to suggest the modification of pipe line/ pump for take more water flow and pressure (desired pressure is 1 kg/cm2)

0 Answers   Simbhaoli Sugars,

Question 55 - The differential equation is 3 dy / dt + 2y = 1 with y(0) = 1. (a) The Laplace transformation, L for given terms are : L (dy / dt) = sY(s) - y(0), L(y) = Y(s), L(1) = 1 / s. Use such transformation to find Y(s). (b) The initial value theorem states that : When t approaches 0 for a function of y(t), it is equal to a function of sY(s) when s approaches infinity. Use the initial value theorem as a check to the answer found in part (a).

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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

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Are there any methods of preventing cracking of carbon steel welds in refining environments?

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HEAT TRANSFER - EXAMPLE 5.3 : In a cylinder with a hollow, let a is outside radius and b is the inside radius. In a steady state temperature distribution with no heat generation, the differential equation is (d / dr) (r dT / dr) = 0 where r is for radius and T is for temperature. (a) Integrate the heat equation above into T(r) in term of r. (b) At r = a, T = c; at r = b, T = d. Find the heat equation of T(r) in term of r, a, b, c, d.

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What is the largest application for surfactants?

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