API 617 is employed for manufacturing a diverse variety of Centrifugal Compressor. These compressors with a high degree of dependability and low maintenance cost are utilized in the petrochemical and refinery sectors, natural gas, steel and cement plants, food industries, and transportation.
How does a centrifugal compressor work?
In several industrial operations, the problem of increasing pressure is crucial. Centrifugal Compressors which are in the category of dynamic compressors can handle high flow rates and medium pressure ratios. The principles governing the design and construction of each of their parts are based on API 617 and API 672 standards (for more information, see what is API672 standard and what is its application? Click). The air enters the first stage chamber through the suction opening equipped with a filtration system and with the inlet flow adjustment by the inlet control valve (IGV: INLET GUIDE VANE). It is pushed towards its center using the impeller blades and is thrown out towards the periphery of the impeller by applying centrifugal force. In fact, by applying centrifugal force, the fluid pressure increases while passing through the impeller.
Which model of centrifugal compressor does Havayar produce?
Integrally geared centrifugal compressor is the kind manufactured by HAVAYAR industrial group. Since each pinion in this type of compressors can operate at the optimum speed, it has a greater overall efficiency than single shaft type. We may also achieve the appropriate pressure ratio with fewer stages than the Single Shaft compressor since the option of utilizing an intercooler after each stage gives us the optimum thermodynamic efficiency throughout the whole compression process.
Technical specifications of air compressors manufactured by HAVAYAR
Centrifugal compressors are manufactured in the power range of 450 kW to 1 MW in HAVAYAR industrial group. These compressors in three and four stages can produce pressure range of 5.5 to 13 bar and their air intake capacity ranges from 3000 to 10000 normal cubic meters per hour.
Another feature of HAVAYAR compressors is the possibility of compressing air to the desired pressure in a wide flow range, this so-called parameter “TURN DOWN RATIO” for HAVAYAR compressors is between 20 and 35 percent.
- The highest efficiency compared to other types of compressors
- Oil-free air outlet without any auxiliary equipment
- Minimal maintenance
- High quality output (no fluctuations in discharge pressure)
- Able to run continuously for a long time
Centrifugal compressor manufacturing innovations
Some of the innovations that cause the complexity of centrifugal compressor production technology are illustrated as follows:
Impeller design according to aerodynamic and rotor dynamic requirements
The first step in the design of the impeller is the aerodynamic design of the compressor and the extraction of diameters, sizes and working cycles based on the data sheet that specifies the performance of the compressor. In the next step, designed items of the structural section are re-analyzed and redesigned and optimized based on the feedback from the structural analysis. According to the design requirements such as output pressure and desired flow rate, the number of compressor stages is determined.
Design and analysis of journal and thrust bearings
The design of bearings to sustain the dynamic stresses on the rotors is one of the most crucial factors in high-speed compressor development. While journal bearings, the first generation of sliding bearings, are widely used in numerous industries, the advanced generation of these bearings, known as TILTING-PAD JOURNAL/THRUST BEARING, with its load capacity and ideal stiffness, has recently been used in the field of rotor dynamics of high-speed equipment. With the suggested innovation, this field has undergone a tremendous transformation. By designing and adjusting the parameters of this group of bearings, different dynamic properties can be achieved in two orthogonal directions. Havayar takes advantage of the existing theoretical and software knowledge in the field of bearing design, by simulating the bearing structure, to optimize the functional parameters of the bearing to obtain the desired dynamic properties based on the working conditions and rotor dynamics. The output of the TILTING-PAD BEARINGS analysis includes the geometry and number of PADs, the pressure profile of the lubricating fluid on the PAD, the changes in the temperature of the lubricating fluid, and the stiffness and dynamic damping coefficients, depending on the operational conditions, one or a number of them can be used as the basis for the design of the case.
One of the design challenges is the gearbox casing design. The structural strength of the casing must be such that it does not enter the yield zone. Also, the dynamic stresses in the structure (due to the presence of rotating components inside the casing set) must be within the acceptable range, and the points with the maximum dynamic stress should be checked with non-destructive (NDT) tests to ensure that there are no cracks or holes in it. be assured