Rotary screw air compressors contact us: 9810599480

Kipc India Pvt. ltd supplied all Rotary Screw Air Compressors, we have authorized dealer. (Yogendra K. Singh Contact us:+91 9810599480)

Rotary screw air compressors

The compressed air source for the factory to our easy to understand information on rotary screw air compressors. On this page, I want to tell you about the pros and cons of the rotary screw compressor, what to look for when buying one and common breakdowns that might occur during operation.

This is a non-stopping process, this kind of compressor doesn’t create a lot of noise; it runs saliently and smoothly. Compared to piston-type reciprocating compressors to the screw compressor is much more costly. But it has to run 24/7 and 365 days a year without any problems. The capacity of screw compressors is generally much high compared to piston-type compressors.

The screw air compressor element was first developed in the 1930s, it has consisted of a male and female rotors. The rotors are of a different shape but fitted each other exactly. When working the male rotor drives then female rotor if it’s an oil-injected screw compressor technology, and a timing gear drives both rotors in the oil-free compressor technology as both rotors will moving harmonically with minimum calculated clearance between both elements.

A rotary air compressor is the best positive displacement compressors. The mostly rotary air compressor is used to the single-stage helical or spiral lobe oil flooded screw air compressor. This Type of compressor consists of two rotors and both rotors are casing where the rotors compress the air internally. This type of compressor is not present valves. These compressor units are basically oil-cooled, where the oil seals in the internal clearances.

Rotary screw air compressors are easy to operate. Capacity control for these compressors is variable speed and variable compressor displacement. The compressor capacity is reduced, When the slide valve opens, bypassing a portion of the compressed air back to the suction. The Best advantages of the rotary screw compressor include smooth and pulse-free air output in a compact size with high output volume over a long life.

The oil-free rotary screw air compressor utilizes especially working to air ends to compress air without oil in the compression chamber yielding true oil-free air. Oil-free rotary screw air compressors are available air-cooled and water cooled and provide the same flexibility as oil flooded rotaries when the oil-free air is required.

OIL-FREE OR LUBRICATED

The rotary screw compressor is available in oil-injected and oil-free versions only. The basic principle is the same but they are different machines.

In this Machine is the big difference in the design of the compressor elements. The oil-injected version needs oil to operate properly, in the oil-free version doesn’t need oil.

The rotors screw compressor used in oil-free screw compressors is the superior quality with very little space in between them. They are not touching each other though; otherwise, they would wear-down too quickly.

Oil-free models are used for specific special applications. I have mostly seen and use them in the big factories like oil/gas or chemical refineries, the big food factories or other places where the compressed air must be 100% oil-free.

If you are require100% oil-free air and lots of it, then oil-free rotary screw compressor  is used

Pros:

• 100% oil-free air

Cons:

• More expensive than oil-injected type compressor
• Servicing/repairing more difficult, and more
  expensive than the oil-injected type
• More noise than oil-injected compressors

OIL-INJECTED ROTARY SCREW COMPRESSORS

There’s oil injected in the compressor element during the compression of the air. This oil is removed after some time by the oil separator, so we end up with clean compressed air.

In the compressor 99, 9% of the oil stays inside the compressor, there is always less oil that passes through the separator and leaves the compressor with the compressed air. This is called oil carryover.

Oil-injected screw compressors don’t produce oil-free air and they can’t be used in places because in industries oil-free air is needed.

Most of the factories, workshops, and machinery, the small oil-carryover of the compressor is not a problem. In fact, it helps to prevent again rust and helps the machines run smoothly.

Example of the small rotary screw compressor.

Pros:

• Quiet operation
• The high volume of air with a steady flow.
• Lower energy cost
• Suitable for continuous operation (24/7)

Cons:

• Expensive compared to piston compressors.
• Not suitable for long stand-stills.
• Oil carry-over.

Reciprocating Air Compressor contact us: +919810599480

Reciprocating Air Compressor

Reciprocating Air Compressor is a positive compressor in which air is sucked in a chamber and compressed with the help of a reciprocating piston which is used by the compressor. It is called as positive displacement. Firstly air is sucked in a chamber and then compression air transfer to decreasing area by the piston. Which does the reciprocating motion is decreased by a piston?

The reciprocating compressor consists of a piston which is enclosed within the cylinder & equipped with suction & discharge valves.

The piston receives power through the crankshaft and connecting rod. A flywheel/belt wheel is fitted on the crankshaft which is connected by the electric motor or diesel engine. The uniform motion throughout the cycle of operations.

The compression air is first drawing a volume of air into the cylinder through suction valves during by the piston stroke. The compressing & discharging on the return stroke of the piston through delivery valves.

This working is used in every Reciprocating Air Compressor. You will easily understand compressor engineering from the below description.

The main three type of air compressor is used for industrial works:

1.)   The Single Stage Reciprocating Air Compressor Works

2.)   The Double Stage Reciprocating Air Compressor Works

3.)   The three-stage air compressors works

Single Stage Reciprocating Air Compressor Works

The single stage reciprocating air compressor, the entire compression air is carried out by the single cylinder.

The compression air is affected in one end of the piston. The cylinder is known as single acting, the compression air is affected in both ends of the piston, the cylinder is known as a double acting reciprocating air compressor.

The opening & closing of a simple check valve depends upon the differential pressure, if mechanically operated valves are used for suction & discharge then their functioning is controlled by cams which are on the wheel.

The weight of air in the cylinder will be zero when the piston is at the top dead center at this position. When piston moving downwards, the pressure inside the cylinder in the atmospheric pressure & suction valve/inlet valve opens. The air is drawn into the cylinder through the filter element. This type of operation is known as suction stroke.

When the piston moves to upwards, the compressed air in the cylinder & inlet valve closes when the pressure increases to atmospheric pressure. This is compression stroke of a compressor. The end of this stroke discharge/delivery valve opens & air is transfer to a receiver. It is a double acting reciprocating air compressor. Suction stroke is starting the process at end of the piston. While at the same time working discharge stroke is the process for another end of the piston. We can say that suction & compression took place on both ends of piston & cylinder in double reciprocating air compressor.

Double Stage Reciprocating Air Compressor Works

In double stage or two stages, reciprocating air compressors consists of two cylinders. One is called a low-pressure cylinder and second is called a high-pressure cylinder.

When piston in a low-pressure cylinder is the outer dead center (ODC) the weight of air inside a cylinder is zero, as piston moves towards inner dead center (IDC) pressure falls below atmospheric pressure when suction valves open due to a pressure difference.

The atmospheric air is drawn into the low-pressure cylinder through air suction filter. Air is compressed by the piston and pressure inside & outside the cylinder is equal. When both are equal point suction then valves closed.

The piston moves towards ODC compression air took place and when the pressure of air is in a range of 1.5 kg/cm² to 2.5 kg/cm² then delivery valves opens & this compressed air is entered into a high-pressure cylinder by the intercooler. This is called low-pressure compression.

Both sides suction & discharge stroke took place of the piston then it is called Double Acting Low-pressure compression.

Suction valves of a high-pressure cylinder open when the air pressure in a high-pressure side is below to the receiver pressure & air from low-pressure cylinder drawn into the high-pressure cylinder.

As the piston moves towards the ODC, firstly stage air is compressed. When the air pressure from the low-pressure cylinder and inside the high-pressure cylinder is equal, then the suction valve is closed.

Now the air is compressed by the piston when the pressure in the High-Pressure Cylinder exceeds that of the receiver & discharge valves open. This high-pressure air is delivered to a receiver.

The Same process is repeated in every cycle of operation. Both sides of the piston suction & discharge stroke on the place then it is called double-acting high-pressure compression.

In double stage reciprocating air compressor, the pressure can be made in a range of 5.5 kg/cm² to 35 kg/cm².

Normally we required air pressure above 7.0 kg/cm² & delivery of air above 100 cubic feet/min. this type of pressure used in double stage reciprocating air compressor.

This is the most common popular model used in various types of engineering plants. If we required air pressure above 35 kg/cm², then the double stage reciprocating air compressor is not useful.

 The three-stage air compressors.

Working Principle of Multi-Stage Air Compressor

 

Mostly industries required air pressure of more than 35 kg/cm² to produce their product. For example, a mineral water bottle requires air pressure more than 40 kg/cm². To produce the desired shape of a bottle at the bottom side and other fields in industrial.

In two stages reciprocating air compressor is not useful. We required the air compressor which produces air pressure above 35 kg/cm².

Air pressure is release when achieved by a multi-stage air compressor. Now use three stage reciprocating air compressors as a multi-stage air compressor. If we are required air pressure discharge above 85 kg/cm² then four-stage air compressors are useful.

The working rules or design of multistage air compressor is the same as double stage air compressor.

In the three-stage air compressor, fresh air from the atmosphere enters in the low-pressure cylinder. Air enters through a suction filter.

The air is compressed by piston up to 4 kg/cm² & then delivered to the second stage cylinder through intercooler compression. This type of stage suction and compression took place on both sides of the piston.

Now the second stage cylinder low-pressure air is compressed up to 14 kg/cm² & discharge towards the third stage (high pressure) cylinder through the second intercooler to achieve the air pressure up to the desired discharge pressure.

At high-pressure cylinder, the 14 kg/cm² air pressure is increased up to the require discharge range. In requiring a range from 35 kg/cm² to 85 kg/cm² by the piston reciprocating inside the high-pressure cylinder.

In this stage, suction and compression require both sides of the piston.

The multistage reciprocating air compressor is used in a few industries like Pet Blowing, CNG (Compressed Natural Gas) Center etc.

Centrifugal Air Compressors contact us: +919810599480

Kipc India Pvt. Ltd. supplied all Centrifugal Air Compressors, we have authorized dealer. (Yogendra K. Singh contact us: +919810599480)

The centrifugal air compressor is a dynamic compressor which depends on the transfer to energy from a rotating impeller to the air.

Centrifugal compressors produce high-pressure converting angular momentum imparted by the rotating impeller. The centrifugal compressors rotating at higher speeds than the other types of compressors. These types of compressors are also designed for higher capacity to work because flow through the Air compressor is continuous.

The inlet guide vanes are the most common method to control the capacity of a centrifugal compressor by closing the guide vanes, volumetric flows and capacity are reduced.

The centrifugal air compressor is an oil-free compressor. The oil lubricated running gear is separated to the air by shaft seals and atmospheric vents.

In this article, we will cover each and every point related to the centrifugal compressor or sometimes called the radial compressor.

The centrifugal compressor is quite different from that of a reciprocating or rotary type compressor. The air passes through the rotating impeller it experiences force or work which is called by centrifugal forces. The increase in pressure and velocity or speed of the air flow through the impeller. The air flow loses its velocity after entering in the different section. The actually a fixed or static component that escorts the air flow when it leaves the impeller. This loss in velocity results in an additional increase of pressure. The impeller and the diffuser contribute about 65% and 35% of the total pressure developed in the centrifugal compressor.

1. Casing and inlet: The mentioned components are usually protected or guarded by a casing or housing. A case house consists of the number of bearings in order to provide radial and axial support of the rotor. The cases also contain nozzles along with inlets and discharge flow connections in order to introduce and extract flow from the compressor.

Casings are of two types:-

 a.) Horizontally split

b.) Vertically split

2. Impellers.

The impellers are used to assemble on a steel shaft and this assembly is known as compressor rotor. The rotor provides high velocity to the gas with the blades that are attached to a rotating disc. These blades can be used to forward-leaning, radial or backward-leaning depending to upon the desired output. Mostly the multistage compressors use backward-leaning blades as they provide the widest range of efficiency.

3. Diffuser.

The impeller has extracted the gas with high velocity into a diffuser passage. The diffuser usually compromises two walls which form a radial channel. Because of these arrangements, this velocity of the gas decreases and dynamic pressure is converted into static pressure. The diffuser passages are small space between adjacent diaphragms which generally turns to the gas flow 180° in order to direct it used for towards the next impeller.

4. Collector.

The last stage impeller the gas must be collected and transfer to the discharge flange. The component used to the collect gas discharged through the diffuser is called as the collector, Maybe termed as volute or scroll. The collector may also contain valves and other used instrumentation in order to control the compressor.

Types:

There are two types of it:

1. Single stage centrifugal compressor

2. Multi-stage centrifugal compressor

This compressor works on the same principle.

1. Single stage compressor.

Single stage compressors consist of only a single impeller and it is used for moving the air or other gases up to 3 to 1 compression ratio for either pressure. This compressor is considered to have a beam design or an overhung impeller arrangement. This type of impeller arrangement is used the non-driving end of the shaft. One major advantage of the multistage compressor is that it provides high efficiency and the delivered gas is totally oil and surge free.

2. Multistage compressor.

Multistage compressors consist of 1-10 impellers and it can be arranged in a variety of flow path configurations. The temperature and the compression ratio in every stage are assumed to be constant. Mostly Multistage compressor arranged in straight-through, compound and double flow configurations. The multistage compressor is also considered to have the beam-type design but the impellers are located between the radial bearings.

Applications of centrifugal compressor: 

1. Compressed gas or air: Centrifugal compressor is one of the most simple and efficient ways to obtain or produce compressed air. They are best suited when the demand for air or gas is constant and excessive.

2. Food Industry: Food processing industry depends highly used in this type of compressor as it can provide oil-free compressed air which is necessary for some sensitive petitions.

3. Gas turbines: Gas turbines are used in both axial and centrifugal compressor to provide the necessary compression.

Centrifugal compressors are mostly used in gas turbines such as: 

a.) Turboshaft

b.) Turboprop

c.) Microturbines and

d.) Auxiliary power units

4. Oil refiners, petrochemical and chemical plants: The centrifugal compressors used for the above purposes area. Generally, a horizontally split casing and most of them are used multistage compressors. These types of compressors are generally operated by over-sized steam engines and gas turbines.

5. Refrigeration and air control: Centrifugal Compressors is a wide variety of refrigerants, thermodynamics and are also able to supply compression in water chiller cycles. It has a high demand for use in refrigerators and air conditioners.

 

Advantages

§  a.)  It is relatively agile and easy for the manufacturer to other compressors.

§  b.) This compressor does not require any special foundation and highly energy efficient and reliable.

§  c.) They consist of a small number of rubbing parts and oil-free in nature.

§  d.) It generates per stage higher pressure ratio than the axial flow compressor.

 

Disadvantages.

§  a.) They produce a limited amount of pressure and not suitable for very high compression.

§  b.) They worked relatively high speed an enlightened or worldly mounting is required.

§  c.) They are very sensitive problems such as stalling and choking.

This is all specification centrifugal compressor principle, working, construction, types, advantages, disadvantages. If you like this article, don’t forget to share it on the social network. Subscribe our website for more informative articles.