AXIAL COMPRESSOR

Axial compressor is a kind of machine by which mechanical energy coming from prime mover is converted into pressure energy. Denomination of axial compressor originates from basic direction of flowing mediums in the compressor. Axial compressors have two series: A and AV. A serial compressor has fixed stator blades while AV compressor has all stator blades adjustable. Currently, AV compressors are widely used. The frame size ranges from AV40 to AV140. Generally number of stages is from 2 to 19. Features of such compressor are wide operating conditions and high efficiency at each operating point, more than 90% in some case. Axial compressors are widely applied in the metallurgical, petrochemical, chemical, wind tunnel, power station and Pharmaceutical.

CENTRIFUGAL COMPRESSOR

In order to improve reliability and efficiency of the machine, Shaangu insists on development of new technique, material and process. For air separation field,Shaangu can provide centrifugal compressor (EIZ),single shaft compressor(EZ and EBZ) and multi-stage compressor (EG) according to different requirements. With the progress of the market, Shaangu has started R&D of compressor for air separation plant since 2002. After 10 years of dedicated research, Shaangu has got a good market reference. Now we are able to manufacture and supply 20,000 to 120,000 Nm3/h air separation units.

ROTARY COMPRESSOR

Rotary compressors are the another type of famous compressors.It uses two Asymmetrical rotors that are also called helical screws to compress the air. The rotors have a very special shape and they turn in opposite directions with very little clearance between them.The rotors are covered by cooling jackets.Two shafts on the rotors are placed that transfer their motion with the help of timing gears that are attached at the starting point of the shafts/compressor Working principle-Air sucked in at one end and gets trapped between the rotors and get pushed to other side of the rotors .The air is pushed by the rotors that are rotating in opposite direction and compression is done when it gets trapped in clearance between the two rotors.Then it pushed towards pressure side.

Types of Rotary compressor

Rotary screw compressors are of two types:-
• Oil-injected
• Oil-free
Oil-injected is cheaper and most common than oil-free rotary screw compressors.

Advantages

• Less noisy.
• These are called the work-horses as they supply large amount of compress air. More energy efficient as compared to piston type compressors. The air supply is continuous as compared to reciprocating compressors. Relatively low end temperature of compressed air.

Disadvantages

• Expensive then piston-type compressors.
• More complex design.
• The maintenance is very important
• Minimum one day use is important in a weak to avoid rusting.

Rotary scroll compressor

They are one of the best compressor types in rotary compressors. The air is compressed using two spiral elements. One element is stationary and the other one moves in small eccentric circles inside the spiral. Air gets trapped inside the spiral way of that element get transported in small air-pockets to the center of the spiral. Simply air gets trapped at the outer edge and gets compressed due to reduction of as it travels from outer edge to inner edge. It takes about 2 to 3 turns for the air to reach the pressure output in the center.

Advantages

• Very quiet.
• This is very compact in size.
• Simple design with not so many parts.
• Oil-free design and low maintenance.

Disadvantages

• Output capacity is low.
• Relatively expensive
• You have to buy a new scroll element with the failure of older one even if there is not any big problem.
• The temperature of compressed air is too much high.

Vane Type Rotary Compressor

This is another type of rotary compressor. There is a fixed casing in Vane type compressor in which a rotary rotor disc is placed which has slots that are used for holding the sliding plates. Whenever rotor rotates the disc also rotates thus allowing the sliding plates to slide as the inner surface of casing is eccentric. Whenever the plates moves away from the center a huge amount of air get trapped inside it and with the rotation the sliding plates converge due to its shape and the trapped air get compressed. This results in compression of air.

Advantages

• Easy maintenance.
• Simple in design.

Lobe Type Air Compressor

This is one of the simpler compressor type.In this there is no complicated moving part.There are two lobes attached to the driving shaft by the prime mover.These lobes are displaced with 90 degrees to one another.Thus if one of the lobe is in horizontal direction the other lobes will be exactly positioned at 90 degree i.e in vertical direction.
The air gets trapped from one end and as the lobes rotates the air gets compressed as shown in image.The compressed air is then delivered to delivery line.