Reference no: EM131181418
1. (a) Draw a pV diagram to illustrate the operation of a two-stage compressor with intercooling.
(b) List the advantages to be gained by the use of a multi-stage design compressor.
2. (a) With the aid of a sketch, describe briefly the operating principle of a rotary vane compressor.
(b) State the reasons why oil must be injected into this machine for its efficient operation.
3. (a) A mass of 400 kg is to be raised by the actuation of two identical hydraulic cylinders with a piston diameter of 120 mm. Calculate the required system pressure to just raise the load.
(b) If the load is to be raised 600 mm in 10 seconds, what will be the required flowrate (Q) in f min-17
4. Describe the operation of a variable displacement axial piston (swash plate) pump, indicating the means by which its output is varied.
5. With reference to basic constructional features, contrast the methods of compression employed by positive displacement and dynamic air compressors.
6. An item of plant requires 2 m3 min-1 of pulsation-free and oil-free compressed air supplied at a pressure of 7 bar. Select and size a suitable type of machine with regard to output FAD (free air delivered) and quality of air supply.
7. Air is drawn into a compressor at normal temperature and pressure (N.T.P.) and compressed to a pressure of 6 bar gauge. After compression the air is delivered at 1 .2 m3 min-1 and cooled to a temperature of 30°C, at which point condensate is collected at the rate of 2 litres per hour. Estimate the FAD (N.T.P.) of the compressor, and the relative humidity of the air entering the compressor.
8. Describe the difference between regenerative absorption and chemical absorption air drying.
|
Diminishing returns to taking inventory
: Imagine you have some workers and some handheld computers that you can use to take inventory at a warehouse. There are diminishing returns to taking inventory. If one worker uses one computer, he can inventory 100 items per hour. If you assign one wo..
|
|
Describe some of the assumptions about labor markets
: Draw and label a graph illustrating this case, in which the going wage is $20, the equilibrium wage is $15, 50 million people want to work, but only 30 million are employed.
|
|
Describe campaign strategies that presidential candidate use
: Describe key campaign strategies that a U.S. presidential candidate can use in order to ascend to presidency in today's political environment.
|
|
Solid waste collection division
: Present demand for service: 100,000 cans per week. You can assume that there will be 100,000 cans per week for 52 weeks per year. (You can assume that the demand is the same for both collection and disposal.)
|
|
Operation of a two-stage compressor with intercooling
: Describe the difference between regenerative absorption and chemical absorption air drying - Draw a pV diagram to illustrate the operation of a two-stage compressor with intercooling.
|
|
Why is the examples you gave ethical dilemma
: List the ethical dilemmas, concepts, and theories that impact your scenario. In other words, why is the examples you gave ethical dilemma? Pick one of the ethical dilemmas/scenarios you identified above and describe 3 alternatives ways that a project..
|
|
Explain the existence of unemployment
: Can this phenomenon help to explain the existence of unemployment? Explain in a paragraph.
|
|
Best policies for management of natural resources
: Why is it unlikely environmental economists will never completely agree with ecologists and other environmental advocates on the best policies for management of natural resources? Be sure to mention the different philosophical perspectives of the ..
|
|
What is government by proxy and how do you feel about it
: What is "government by proxy" and how do you feel about it? Does it seem like the best course of action for our government to take given its size and scope?
|