Question

Project about Displacement compressor (positive and non-positive)  include the following topic

1-INTRODUCTION

2-FUNCATION

3-TYPES

4-MAINTENANCE

5-PROBLEMS OF DISPLACEMENT COMPRESSOR

6- USING OF DISPLACEMENT COMPRESSOR

7-ASSEMBLY AND DISASSEMBLY

8- INCLUDE PICTURE ABOUT DISPLACEMENT COMPRESSOR

9-CONCLUSION

NOTE; ANSWER JUST TYPING PLZ

Answer 1

1.INTRODUCTION

A compressor is a mechanical device that increases the pressure of a gas by reducing its volume. since the process of compressing the gas requires that work should be done up on it, it will be clear that a compressor must be driven by some form of prime movers. of the energy received by the compressor from The prime mover some will be absorbed in work done against friction, some Will be lost to radiation and any coolant which might be employed to cool the machiene. Many compressors can be staged, that is, the fluid is compressed several times in steps or stages, to increase discharge pressure. Often, the second stage is physically smaller than the primary stage, to accommodate the already compressed gas. Each stage further compresses the gas and increases pressure.

2.FUNCTION

The compressor air finds application in the following fields

1.In pipeline transport of purified natural gas from the production site to the consumer, a compressor is driven by a gas turbine fueled by gas bled from the pipeline. Thus, no external power source is necessary.

2. a large quantity of air at moderate pressure is used in smelting of various metals such as melting iron, in blowing, cupola works

3. large quantities of air are used in the air conditioning, drying, and ventilation fields

The function of a compressor is to take a definite quantity of fluid( usually gas and most often air) and deliver it at a required pressure.

4.Various industrial, manufacturing, and building processes require compressed air to power pneumatic tools.

5.In the manufacturing and blow moulding of PET plastic bottles and containers.

6.Some aircraft require compressors to maintain cabin pressurization at altitude.

7.Some types of jet engines—such as turbojets and turbofans—compress the air required for fuel combustion. The jet engine's turbines power the combustion air compressor.

8.In SCUBA diving, hyperbaric oxygen therapy, and other life support devices, compressors put breathing gas into small volume containers, such as diving cylinders.[30][31]

9.In surface supplied diving, an air compressor frequently supplies low pressure air (10 to 20 bar) for breathing.

10.Submarines use compressors to store air for later use in displacing water from buoyancy chambers to adjust depth.

11.Turbochargers and superchargers are compressors that increase internal combustion engine performance by increasing the mass flow of air inside the cylinder, so the engine can burn more fuel and hence produce more power.

12.Rail and heavy road transport vehicles use compressed air to operate rail vehicle or road vehicle brakes—and various other systems (doors, windscreen wipers, engine, gearbox control, etc.).

13.Service stations and auto repair shops use compressed air to fill pneumatic tires and power pneumatic tools.

14.Fire pistons and heat pumps exist to heat air or other gasses, and compressing the gas is only a means to that end.

3.TYPES

compressors are classified into positive displacement and negative displacement compressors.

1.POSITIVE DISPLACEMENT COMPRESSORS

Positive displace compressor increase the pressure of air by reducing its volume. This means a positive displacement compressor takes successive volume of air which is confined in a closed place and elevating this air to higher pressure. The compressor accomplishes this by a piston within a cylinder as the compressing and displacing element.

there are two type of positive displacement compressors

1.Reciprocating compressor

it consist of a piston which reciprocates in a cylinder, driven through a connecting rod and crank mounted in a crank case. there are inlet and delivery valves mounted in the head of cylinder. They can be either stationary or portable, can be single or multi-staged, and can be driven by electric motors or internal combustion engines.[2][3][4] Small reciprocating compressors from 5 to 30 horsepower (hp) are commonly seen in automotive applications and are typically for intermittent duty. Larger reciprocating compressors well over 1,000 hp (750 kW) are commonly found in large industrial and petroleum applications.

2.Rotary compressors

Rotary compressors are the Machines which develop pressure and have a rotor as their primary element when compared with the piston sliding mechanism of the reciprocating compressor. whenever large quantities of air or gas are required at relatively low pressure rotary compressors are employed.

classification

1. Roots blower

2. sliding vane compressors

3. screw compressor

4.lysholm compressor

2.NON POSITIVE DISPLACEMENT COMPRESSORS(STEADY FLOW)

The compressors in which Compression occurs by transfer of kinetic energy from a rotor. These type of compressors produce high- pressure discharge by converting angular momentum imparted by the rotating impeller. Generally these compressors rotate at higher speed than positive displacement compressors.

1. centrifugal compressors

The centrifugal compressors was used in the earliest gas turbine units of air craft. For low pressure Ratios(no greater than 4:1)the centrifugal compressor is lighter and is able to operate effectively over a wide range of mass flow at any one speed, than its axial flow counter part.

2.Axial compressors

Axial compressors are dynamic rotating compressors that use arrays of fan-like airfoils to progressively compress a fluid. They are used where high flow rates or a compact design are required.

The arrays of airfoils are set in rows, usually as pairs: one rotating and one stationary. The rotating airfoils, also known as blades or rotors, accelerate the fluid. The stationary airfoils, also known as stators or vanes, decelerate and redirect the flow direction of the fluid, preparing it for the rotor blades of the next stage.

4.PROBLEMS OF DISPLACEMENT COMPRESSORS

You can think of Positive Displacement Compressors as a Discontinuous Flow.

Its opposite is the Dynamic Compressor. Which has a Continuous Flow.

The positive displacement compressor is discontinuous. It means is splits up the compressing process into different stages.

Typically these stages are the Intake, Compression, and Output which can be in the form of compressed fluid, or translated into work.

In any Positive Displacement Compressor, we can split up these stages into their individual pressure values. They do not affect the other stages.