can you do this 2 easy assignment

Week 12 Assignment 10

Use the reading assignment from Chapter 7 in your text to answer the following

question:

Question 1 (8 points)

Using a sweep through purging method, inert a 100-gallon vessel containing 100% air

until the oxygen concentration is 1%. What volume of nitrogen is required? Assume

nitrogen with no oxygen and a temperature of 77 °F.

Question 2 (14 points)

A 150-ft3 tank containing air is to be inerted to 1% oxygen concentration. Pure Nitrogen

is available for the job. Because the tank’s maximum allowable working pressure is 150

psia, it is possible to use either the sweep-through or pressurization technique. For the

pressurization technique, multiple pressurization cycles might be necessary, with the

tank being returned to atmospheric pressure at the end of each cycle. The temperature

is 80 °F.

a. Determine the volume of nitrogen required for each technique.

b. For the pressurization technique, determine the number of cycles required if the

pressure purge includes increasing the pressure to 140 psia with nitrogen and

then venting to 0 psig.

Question 3 (8 points)

Use a vacuum purging technique to purge oxygen from a 150-ft3 tank containing air.

Reduce the oxygen concentration to 1% using pure nitrogen as the inert gas. The

temperature is 80 °F. Assume that the vacuum purge goes from atmospheric pressure

to 20 mm Hg absolute. Determine the number of purge cycles required and the total

moles of nitrogen used.

Week 11 Assignment 9

Use the reading assignment from Chapter 12 in your text to answer the following

question:

Question 1 (15 points)

Given the fault tree gates:

And the following set of failure probabilities:

1. Determine an expression for the probability of the top event in terms of the

component failure probabilities.

2. Determine the minimal cut sets.

3. Compute a value for the failure probability of the top event. Use both the

expression of Part 1 and the fault tree itself.

Question 2 (15 points)

The storage tank system shown below:

Is used to store process feedstock. Overfilling of storage tanks is a common problem in

process industries. To prevent overfilling, the storage tank is equipped with a high-level

alarm and a high-level shutdown system. The high-level shutdown system is connected

to a solenoid valve that stops the flow of input stock.

1. Develop an event tree for this system using the “failure of level indicator” as the

initiating event. Given that the level indicator fails 4 times/year, estimate the

number of overflows expected per year. Use the following data:

2. Develop a fault tree for the top event of “Storage Tank Overflows.” Use the data

in Table 12-1 in your text to estimate the failure probability of the top event and

the expected number of occurrences per year. Determine the minimal cut sets.

What are the most likely failure modes? Should the design be improved?