SAFE4160

University of Central Missouri

### Question Description

I’m stuck on a Physics question and need an explanation.

- The hood static pressure is measured at SPh = –2.00 "w.g., and the average duct velocity pressure is measured to be VP = 0.80 "w.g. What is the hood entry loss, he, and the Coefficient of Entry, Ce?
- Air enters a 6” diameter duct through a flanged hood; SPh = -1.25” w.g., Ce = 0.82, d = 1. What is the estimated volume flow rate, Q?
- Air flows into flow into a 6” diameter duct through a flanged hood; at a rate of Q = 560 scfm; SPh = -0.75” wg (measured) and d = 1 (standard conditions). What is the estimated Coefficient of Entry, Ce? After your calculation, please compare your result to Chart 11 and make a conclusion.
- Use Chart No. 11 to find Fh and Ce for the following three hoods, and then calculate the hood entry loss (he), VPd and the SPh for each hood. Assume STP.
- Air flows through a slotted and flanged “Lateral Exhaust Hood” mounted on an open-surfaced liquid tank. Measured hood parameters include: h = 2 feet, W = 2 feet, L = 4 feet. Assume STP.

Hint: Use Equations 27 and 30 from the Workbook.

Hint: Use Equation 33.

Hint: Use Equation 33.

A. A bell mouth hood, duct velocity = 4,000 fpm

B. A round tapered hood, included angle of 90-degrees, duct velocity = 2,900 fpm.

C. A plain duct hood, duct velocity = 3,750 fpm.

- What is the recommended range of capture velocities at the edge of tank for this type of hood? (Hint: Use Chart 8 and look for open surfaced tank)
- Assume Vc = 100 fpm. What is the required exhaust air volume flowrate, Q? (Hint: Use chart 11 to determine the Area, and use Hemeon method Q = Vc * A).
- Then calculate Q using the recommended Q equation in the Chart 11D method for a “General Dip Tank”.
- Compare two Q results, and discuss the reasons.

**Attachment preview**

Safe 4160: Industrial Ventilation

Chapter 6 And Complete The Following Questions Independently!

You Need To Show Equation, Your Calculation Process And Proper Unit For Credits.

1. The Hood Static Pressure Is Measured At Sph = -2.00 "w.g., And The Average Duct Velocity Pressure Is Measured To Be Vp = 0.80 "w.g. What Is The Hood Entry Loss, He, And The Coefficient Of Entry, Ce?

Hint: Use Equations 27 And 30 From The Workbook.

2. Air Enters A 6" Diameter Duct Through A Flanged Hood; Sph = -1.25" W.g., Ce = 0.82, D = 1. What Is The Estimated Volume Flow Rate, Q?

Hint: Use Equation 33.

3. Air Flows Into Flow Into A 6" Diameter Duct Through A Flanged Hood; At A Rate Of Q = 560 Scfm; Sph = -0.75" Wg (measured) And D = 1 (standard Conditions). What Is The Estimated Coefficient Of Entry, Ce? After Your Calculation, Please Compare Your Result To Chart 11 And Make A Conclusion.

Hint: Use Equation 33.

4. Use Chart No. 11 To Find Fh And Ce For The Following Three Hoods, And Then Calculate The Hood Entry Loss (he), Vpd And The Sph For Each Hood. Assume Stp.

A. A Bell Mouth Hood, Duct Velocity = 4,000 Fpm

B. A Round Tapered Hood, Included Angle Of 90-degrees, Duct Velocity = 2,900 Fpm.

C. A Plain Duct Hood, Duct Velocity = 3,750 Fpm.

5. Air Flows Through A Slotted And Flanged "lateral Exhaust Hood" Mounted On An Open-surfaced Liquid Tank. Measured Hood Parameters Include: H = 2 Feet, W = 2 Feet, L = 4 Feet. Assume Stp.

" What Is The Recommended Range Of Capture Velocities At The Edge Of Tank For This Type Of Hood? (hint: Use Chart 8 And Look For Open Surfaced Tank)

" Assume Vc = 100 Fpm. What Is The Required Exhaust Air Volume Flowrate, Q? (hint: Use Chart 11 To Determine The Area, And Use Hemeon Method Q = Vc * A).

" Then Calculate Q Using The Recommended Q Equation In The Chart 11d Method For A "general Dip Tank".

" Compare Two Q Results, And Discuss The Reasons.

### Unformatted Attachment Preview

Purchase answer to see full attachment

## Final Answer

Attached.

SAFE 4160: Industrial Ventilation

Name:

Institution:

Course:

Date:

2

Chapter 6 and complete the following questions independently!

You need to show equation, your calculation process and proper unit for credits.

1. The hood static pressure is measured at SPh = –2.00 "w.g., and the average duct velocity

pressure is measured to be VP = 0.80 "w.g. What is the hood entry loss, he, and the

Coefficient of Entry, Ce?

Hint: Use Equations 27 and 30 from the Workbook.

SPh=-(VP+he)

-2.00=-(0.8+he)

Ce=√(VP/SPh)

Ce=√(0.8/2)

he=1.6”w.g.

Ce=0.63

The hood provides 63% of ideal ...

Brown University

1271 Tutors

California Institute of Technology

2131 Tutors

Carnegie Mellon University

982 Tutors

Columbia University

1256 Tutors

Dartmouth University

2113 Tutors

Emory University

2279 Tutors

Harvard University

599 Tutors

Massachusetts Institute of Technology

2319 Tutors

New York University

1645 Tutors

Notre Dam University

1911 Tutors

Oklahoma University

2122 Tutors

Pennsylvania State University

932 Tutors

Princeton University

1211 Tutors

Stanford University

983 Tutors

University of California

1282 Tutors

Oxford University

123 Tutors

Yale University

2325 Tutors