In step 4 why 0.75/3? if the problem says that we have tubes with 1 meter? https

Question

In step 4

why 0.75/3?

if the problem says that we have tubes with 1 meter?

https://www.chegg.com/homework-help/Design-of-Fluid-Thermal-Systems-SI-Edition-4th-edition-chapter-9-problem-5P-solution-9781305076075

5. A sugar solution (p-1080 kg/m3, Cp 3 601 J/(kg.K), ky 0.576 4 W/(m-K), and u 1.3 x 10 N-s/m-) flows at a rate of 60 000 kg/hr and is to be heated from 25°C to 40°C. Water at 95 C is available at a flow rate of 75 000 kg/hr. It is proposed to use a 12-in.-ID, 1-2 shell and tube heat exchanger containing 3/4- in.-OD, 16 BWG tubes, 1 m long and laid out on a 1-in. square pitch. The exchanger contains three baffles spaced evenly. Will the exchanger be suitable? If not, can it be made to work by doubling the flow rate of the water? Find outlet temperatures for the configuration that works when the exchanger is new

Explanation / Answer

The tube is 1m long. So the entrance length i.e the length in which the flow is fully developed which means the boundary layer is formed completly acroos the tube is 1/4 =0.25 m . So 0.25m is provided such that flow becomes fully developed and the remaining 0.75 m is divided by 3 as the baffles are equispaced.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.