Question

Steam at its saturation temperature of 65°C is condensing on the
outside

of a tube with outside diameter 2.5cm and length 3m. The tube
is

maintained at 35°C by flow of cooling water through it. Calculate
the

average heat transfer coefficient over the tube length and the rate
of

condensate flow at the bottom of the tube. Physical properties can
be

found in data tables.

Find the heat transfer coefficients for the vertical and horizontal tubes using both the Nusselt equation and the McAdams equation.

Answer #1

Steam

T1 = 65°C

Tf = 35°C

d = 2.5 cm

L = 3 m

From Perry handbook physical properties are calculated at average temperature = (65+35) /2 = 50°C

Kf = 0.6436 W/mK

= 0.0831 kg/m3

= 10×10-6 Pas

= 2346.304 KJ/kg

For horizontal tubes

h = 35.3466 W/m2K

For vertical condenser

h = 13.890 W/m2K

= 0.6436/(13.890) = 0.04633

Subsituting we get

= 0.22464

For vertical condenser

m = 0.22464(3) = 0.67392 kg/s

Please upvote if helpful

A 10-mm diameter tube has a maintained surface temperature of
200°C. Engine oil enters the tube at 70°C at a flow rate of 0.5
kg/s and exits at 105°C. Find the length, in m, of the tube and
well as the corresponding heat transfer rate, in W. Assume fully
developed flow and use the Dittus–Boelter equation to calculate the
average Nusselt number.
q = . L =

An air-cooled steam condenser is operated with air in cross flow
over a square, in-line array of 400 tubes (NL=NT= 20), with an
outside tube diameter of 20 mm and longitudinal and transverse
pitches of SL= 60 mm and ST= 42 mm, respectively. Saturated steam
at a pressure of 2.455 bars enters the tubes, and a uniform tube
outer surface temperature of Ts= 390 K may be assumed to be
maintained as condensation occurs within the tubes.
(a) If the...

10. Air is to be heated by passing
it over a bank of 2.8-m-long tubes inside which steam is condensing
at 90ºC. Air approaches the tube bank in the normal direction at
20ºC and 1 atm with a mean velocity of 5.2 m/s. The outer diameter
of the tubes is 1.6 cm, and the tubes are arranged staggered with
longitudinal and transverse pitches of SL = ST= 4 cm. There are 30
rows in the flow direction with 10 tubes...

Question 2. Answer all parts of this question a) A shell and
tube heat exchanger is to heat 10,000 kg h–1 of water from 16 to
84°C using hot oil entering at 160°C and leaving at 92°C. The oil
will flow through the shell of the heat exchanger. The water will
flow through 11 brass tubes of 22.9 mm inside diameter and 25.4 mm
outside diameter, with thermal conductivity 137 W m–1 K–1, with
each tube making two passes through...

A shell and-tube heat exchanger is required for the following
service:
Hot stream
Cold Stream
Aromatic Stream
Cooling Water
inlet Temperature (oC)
85
20
outlet Temperature (oC)
40
35
Mass Flowrate x heat Capacity (kW/oC)
85.2
Hot Stream
cold stream (Cooling water)
Heat Capacity (J/kg K)
2840
4193
Density (kg/m3)
750
999
Viscosity (cP)
0.34
1.016
Thermal conductivity (W/m.K)
0.19
0.594
Fouling Factor (m2.oC/W
0.00018
0.000176
? The cooling water is allocated to the tube-side of the
exchanger.
? It...

Water at 15°C enters a tube of 2 cm of diameter with flow rate
3953 kg/h. Assume the ratio L/D>10, and the wall temperature is
constant at 80-C. The outlet temperature is 50°C The properties of
water at the film temperature are density rho = p = 985 kg/m3,
specific heat Cp = 4180 J/kgk, conductivity k = 0.651 W/mK, dynamic
viscosity mu= u = 4.71 × 10- kg/ms, At the wall temperature of 80°C
we have dynamic viscosity muw=...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 1 minute ago

asked 4 minutes ago

asked 17 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago

asked 2 hours ago