Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Mechanical Engineering Expert

problem1.    Part A
A compressor installed at a wharf (for loading container ships) is able to give 6 bar.g pressures into the pressure receiver. The compressor is moved to a site that is 5000 ft above sea level (atmospheric pressure 0.85 bar.a) in the mountains. What is the revised discharge pressure (guage pressure) of the compressor?
Assume there is no change in temperature.

Part B

Is the assumption of change in temperature valid for calculating the discharge pressure of the compressor?

Part C

The temperature at the wharf is 35 oC and in the mountains is 19 oC, what is the reduction in volumetric output from compressor?

Questio2.

The system on site is a pressure sand filter, with a service curve. The filter is backwashed using the feed pump, at a higher flow rate, shown as backwash curve.

1162_centrifigual pump curve.jpg

Service duty point: 3 m3/h
Backwash duty point: 9 m3/h

Part A

What is the speed of the pump to achieve the service and backwash flow rates?

Part B

What would be the best way to control the speed of the pump? Why?

Part C

The pump is set up as a fixed speed constant pressure system (pump runs once system pressure reaches 550 kPa, turns off, when pressure drops to 450 kPa plant re-starts) to maintain a system pressure of 500 kPa at the discharge of the pump. What would be the service and backwash rates from the pump?

problem3.

A pump station has been designed to lift water out of a 6 metre deep pit (vented to atmosphere) via a centrifigual pump mounted at ground level.
   
    Liquid conditions     20 OC
    Suction pipe work losses    2.0 metres
    NPSH safety factor                 5.0 kPa
    Vapor pressure @ 20oC    0.25 metres

Part A 

find out the Net Positive Suction Head (NPSH) for the system?

Part B

In summer the liquid temperature rises to 60 oC, this changes the water vapor pressure to 2.05 metres. What is the revised NPSH for the higher water temperature?

Part C

Pressure loss in the suction pipe work is directly proportional to water veloicty in the pipe work squared, which is inversely proportional to suction pipe work diameter squared.

problem4.

We have a reciprocating compressor operating at 800 rpm.  Suction pressure and discharge pressure are held constant by other systems that have nothing to do with the compressor.  We increase the speed from 800 to 840 rpm (a 5% increase).

Part A
 What is the change in flow rate through the compressor Flow increases by (840/800) or 1.05, or 5% increase?

Part B
What is the change in pressure rise through the compressor?

Part C

What is the change in power that must be delivered to the compressor?

problem5.

We are operating a centrifugal compressor. The gas composition does not change during this excursion.  While holding suction pressure and flow rate constant, the inlet temperature rises.  What would you expect to happen to the discharge pressure, and why?

Mechanical Engineering, Engineering

  • Category:- Mechanical Engineering
  • Reference No.:- M9685

Have any Question? 


Related Questions in Mechanical Engineering

1 what are modes of failure2 what are failure criteria how

1. What are modes of failure? 2. What are failure criteria? How are they related to modes of failure? 3. What is meant by the term factor of safety? How are factors of safety used in design?

Invent a structure that can completely eliminate the narrow

Invent a structure that can completely eliminate the narrow gate effects. This is known as the fully recessed stepped oxide (FROSOX) whose sidewall oxide is thicker than the gate oxide and they are connected by a step or ...

The figure illustrates the operation of an air lift pump

The figure illustrates the operation of an air lift pump. Compressed air is forced into a perforated chamber to mix with the water so that the specific gravity of the air-water mixture above the air inlet is 0.5. Neglect ...

A steel bar of 100mm length tapers from 12mmtimes10mmfrom

A steel bar of 100mm length tapers from 12mm×10mmfrom one end to 30mm×20mm at the other. If the stress in the bar is not to exceed 100mpa,find the magnitude of the axial force. Also find the change in its length. Take E ...

A water jet pump has an area ajnbsp 006 ft2nbspand a jet

A water jet pump has an area A j  = 0:06 ft 2  and a jet velocity v j  = 90 fps, which entrains a secondary stream of water having a velocity v s  = 10 fps in a constant-area pipe of total area A = 0.6 ft 2 . At section ...

At the transition temperature of 954degc the enthalpy of

At the transition temperature of 95.4°C, the enthalpy of transition from rhombic to monoclinic sulfur is 0.38 kJ mol -1 . a. Calculate the entropy of transition under these conditions. b. At its melting point, 119°C, the ...

The top figure shows a diagram of the bones and biceps

The top figure shows a diagram of the bones and biceps muscle of a person's arm supporting a mass. The lower figure shows a biomechanical model of the arm, in which the biceps muscle AB is represented by a bar with pin s ...

Example how an p-channel flash eprom would work is the

Example how an p-channel flash EPROM would work. Is the p-channel worse or better than the n-channel asides form speed? Estimate the write and erase times (using the Fowler-Nordheim tunneling formulae for a triangular ba ...

In order to penetrate a workpiece a tungsten carbide drill

In order to penetrate a workpiece, a tungsten carbide drill bit is subject to a torque of 3.8 Nm and an axial force of 5 kN. Tungsten carbide is very strong (compressive strength 1400 MPa, tensile strength 340 MPa) but a ...

Part 1- heat1 the is used to express absolute temperatures

Part 1- Heat 1. The _______ is used to express absolute temperatures in the English system of measurement. A. Rankine scale B. Celsius scale C. Kelvin scale D. Fahrenheit scale 2. A silver bar 0.125 meter long is subject ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

WalMart Identification of theory and critical discussion

Drawing on the prescribed text and/or relevant academic literature, produce a paper which discusses the nature of group

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro