Shell-and-tube heal exchangers

Hot oil is to be cooled in a multipass shell-and tube heal exchanger by water. The oil flows through the shell, with a heat transfer coefficient of/i = 35 W/m - X, and the water flows through the tube with an average velocity of 3 in/s. The lube is made of brass (k = 110 W/m X) with Internal and external diameters of 1.3 cm and 1,5 cm, respectively. Using water properties at 25X, determine the overall heat transfer coefficient of this heat exchanger based on ihe inner surface. 

A shell-and-tube heat exchanger is used as an ammonia condenser with ammonia vapor entering the shell at 50°C as a saturated vapor. Water enters the single-pass tube arrangement at 20°C and the total heat transfer required is 200 kW. The overall heat-transfer coefficient is estimated from Table I0-I as 1000 W/m2 °C. Determine the area to achieve a heat exchanger effectiveness of 60 percent with an exit water temperature of 40°C. What percent reduction in heal transfer would result if the water flow is reduced in half while keeping the heat exchanger area and V the same ... 

Flow across cylinders and splieres is frequently encountered in practice. For example, the lubes in a shell-and-tube heat exchanger involve both internal flow through the lubes and external flow over the tubes, and both flows must be considered in the analysis of the heal exchanger. Also, many sports such as soccer, tennis, and golf involve flow over spherical balls. 

A shell-aod-tube heal exchanger vvilb 2-sheII passes and 12 lube passes is used lo heal waicr (c = 41801/kg "Q in the lubes from 20°C to 70°C at a rate of 4.5 kg/s. Heat is supplied by hot oil (c, = 2300 JAcg "C) that enters the shell side at I70°C at a rate of 10 kg/s. For a tube-side overall heat transfer coefficient of 350 W/m °C, determine the heat transfer surface area on the lube. side. Answer 25.7 rn ... 

A shell-and-tube heat exchanger with 2-shell passes and 8-lube passes is used to heal ethyl alcohol (c = 76701/kg °C) in the tubes from 25°C lo VO C at a rate of 2.1 kg/s. The heating is to be done by water (c 4190 J/kg °C) that enters the shell... 

A shell and tube heat exchanger is used for preheating the feed to an evaporator. The liquid of specific heat 4.0 kJ/kg K and specific gravity 1.1 passes through the inside of the tubes and is heated by steam, condensing at 395 K on the outside. The exchanger heats liquid at 295 K to an outlet temperature of 375 K when the flow rate is 175 cinVs and to 370 K when file flowrate is 325 cm /s. What is the heal transfer area and the value of the overall heat transfer coefficient when the flow is 175 cm /s ... 

A typical evaporator will consist of a shell-and-tube heat exchanger. Refrigerant will be on the shell side as shown in Figure 10-3. The refrigerant liquid level should be sufficient to cover all tubes if maximum refrigeration capacity is desired. Any factor that causes tubes to be exposed in the vapor space will reduce evaporator heal transfer and, hence, refrigeration duty. 

Essentially, a shell and tube exchanger consists of a bundle of tubes enclosed in a cylindrical shell. The ends of the tubes are fitted into tube sheets which separate the shell-side and tube-side fluids. Baffles are provided in the shell to direct the fluid flow and increase heal transfer. ... 

Expansdon joint For heal exchangers with fixed tube sheets, if tube and shell side fluid temperatures are far apart, thermal expansion of shell and tubes will be different. Ifthetempcniture difference is gieater than 200 usually expansion joint is required at shell to avoid tube joints at tube eet hecora.es loose. 

The shell ami tube exchanger is by far the most commonly used type of heal transfer equipment in the chemical and allied industries. The advantages of this type are... 

SOLUTION Glycerin is healed in a 2-shell passes and 4-tube passes heal exchanger by hot water. The rate of heat transfer for the cases of fouling and no fouling are to be determined. 

A tesi is conducted lo detennine the overaU heal transfer coefficient in a shell-and-Cube oil-to-watcr heat exchanger that has 24 tubes of internal diameter 1.2 cm and length 2 m in a single. shell. Cold water (c, = 4180 J/kg - "C) enters the tubes at 20°C at a rate of 3 kg/s and leaves at 55°C. Oil Cp = 2150 J/kg C) flows through the shell and is cooled from 120 C to 45 C. Detennine the overall heal transfer coefficient Ui of this heat exchanger based on the inner surface area of the tubes, /tnsiver 8.31 kW/m C... 

Cold water (Cp = 4180 J/kg C) enters the tubes of a heal exchanger with 2-shell passes and 23-Uibe passes at 14"C at a rate of 3 kg/, while hot oil (Cp 2200 J/kg Q enters the shell at 2(X) C at Ihe same mass flow rate. The overall heat transfer coefficient based on the outer surface of Ihe tube is 300 W/m "C and the heat transfer surface area on that side is 20 m Deieiinine the rate of heat transfer using (a) the LMTD method and (b) the e-NTU method. 

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