Rotary screw compressor series belonging displacement. […]
Rotary screw compressor series belonging displacement. A positive displacement pump to produce a flow by applying suction side expansion chamber and the discharge chamber is applied to a decrease side. Accumulated displacement machine inside a fixed volume of gas, and then discharged into an exhaust manifold or compressed.
Today, the two most commonly used compressor is a rotary screw (screw rotor) and a reciprocating piston. In comparison, a rotary screw valve is not used, the weight ratio of the light reciprocating piston, ripple-free, thus requiring less demanding on the basis, and since the rotor never contact each other, thus retaining their design efficiency over the entire operation time. Screw compressor was originally designed in the mid-1950s, eventually develop into running between the reciprocating piston and centrifuge capabilities for commercial, industrial and natural types of applications.
A screw compressor driven by rotation of the screw rotor accommodated in the housing two mutually engaging components. Between the rotor and the gap between the housing and the rotor 003 is generally "0.005." Extending the male rotor or the drive rotor is connected via a shaft by a motor or engine. In the case where the oiling machine, a male rotor female rotor is driven by an oil film. Dry type screw compressor using a set of timing gears to achieve the proper rotation.
The final pressure and volume adjustment of rotor diameter and length of the machine can produce. As the rotor diameter increases, the pump capacity is increased. With increasing length of the rotor, the ultimate pressure of the pump increases.
When a force is applied to the outer rotor, it starts with the outer rotor is disengaged, thereby forming a gap to allow gas through the intake port. When holding the rotor passes the intake port, the engaging space will continue to expand until the gas is completely filled up the space between the blades. When the male rotor blade into the gap, and it starts to transmit the compressed gas to the exhaust port. With the rotation of the rotor, the aeration tank is isolated from the housing wall, forming a compression chamber, and in which the lubricant is injected to provide cooling, sealing and lubrication.
Continued rotation will reduce the amount of gas to the provisions of the design pressure. And the compressed gas through the discharge port into the final lubricant, and then into two-phase separator, where the oil is separated. 10 microns automotive type oil was spin-filters, then through the air or water cooled, and then re-injected into the compression chamber. The type of oil used in the machine is 220 or ISO 100,150 hydrocarbon composition viscosity, selected according to the specific gravity and the gas. The right choice for gas analysis essential oil, because the viscosity during the initial startup, the gas will dilute the oil. In the case of an air compressor, the gas is then directed to an air-cooled after cooler in the cooler, up to 70% of uptake of water vapor condensed out of the gas stream entering the supply manifold before.
Ports positioned and compressed to reach the pressure ratio is applied. For maximum efficiency, the application corresponding to the geometry of the pressure requirements to match the key. Some rotary screw compressor design uses a variable exhaust valve, the exhaust valve is continuously variable seeks to maximize efficiency by opening and closing system according to the pressure conditions. When the air compressor is sensed reduced demand system (pressure rise), the exhaust valve to allow air circulation back to the intake port, without compression to meet system requirements. The end result is a short length of the rotor, resulting in a variable displacement operation, thus reducing power requirements.
Displacement screw compressor is a function of the volume between the blades and the rotational speed. It is a function of the volume between the rotor blade profile, length and diameter. Volume between lobes may be represented by the equation;
Qr = d3 (L / d) / C
Wherein: Qr = Displacement / d = diameter of the rotor revolution C = Constant typical profile
Qd = Qr x N
Where: Qd = emission speed of the compressor N = Qi = Qd x Ev
Where Qi = actual intake air volumetric efficiency Ev =
Volumetric efficiency is a function of rotor slip, the slip is expanded by the rotor back to the low pressure side of the gas generated by internal leakage, thus reducing the potential capacity of the compressor.
Adiabatic compression may be assumed, assuming no energy (heat) to the energy transfer from the gas or gas during compression, and provide all the power is applied to the internal energy of the gas, resulting in increased pressure and temperature, to assess the screw compressor exhaust gas temperature.
The adiabatic temperature increase by the adiabatic efficiency by dividing and multiplying the temperature rise efficiency of the cooling temperature is calculated to calculate the emission temperature. To find the final exhaust temperature, the inlet temperature set in the temperature rise was added.
t2 = t1 + T1 (rpk-1 / k-1) / na x nt
Wherein: rp = pressure ratio na = temperature efficiency adiabatic efficiency nt =