Rotors compressors

The nonflooded compressor rotor leakage can be related to the rotor tip h number. The rotor tip velocity can be calculated by... 

The seal unit located at each end of the multistage compressor rotor is installed as a cartridge. The cartridge has positive locating features to permit proper placement on installation. It normally includes a provision to ensure that cartridges are not interchanged from the intended end. This is to prevent reverse rotation on the unidirectional configurations. 

The value is lower than the. Ig would call for, but most users would prefer to install a compressor rotor balanced with some residual unbalance margin. 

Answer—it runs faster It is easier to spin the compressor rotor when its efficiency is impaired. The salt-encrusted wheels do not bite as hard into the gas as would clean wheels. But the amount of gas moved is reduced, even though the rotor is spinning faster. 

Now, let us again assume that our natural-gas compressor rotor begins to foul with salt, drilling mud, and/or a paraffin wax, produced with the gas. Here is what will happen ... 

Strange to say, but we could move almost as much natural gas with a dirty compressor rotor as we could with a clean compressor rotor. Of course, the amount of fuel we needed to run the turbine increased substantially as the rotor salted up. But our fuel in Laredo was self-produced, and therefore more or less free natural gas, so we did not care. 

Turbine rotor and stator blades 6 = Compressor rotor and stator blades 11 = Blade carrier 12 = Cooling-air admission G = Hot gas... 

If mist eliminators are used, they must be carefully designed, specified, and supported. Plugging of mist eliminator pads is not an uncommon problem. Occasionally, a dislodged part of a mist eliminator pad is sucked into the compressor rotor or becomes lodged in downstream piping (232, 239). These potential problems should be discussed with the manufacturer. The beneficial effects and the various types of mist eliminators available are extensively described elsewhere (101, 165, 270, 431 33). 

Compressor rotor assembly Stator blades, rotor blades Compressor case assembly Air inlet filter assembly Bearings and seals Compressor diffuser assembly... 

A variety of solids such as corrosion products, sublimed ammonia salts and coke fines can accumulate on a centrifugal wet gas compressor rotor. One indication of a problem is a high amp load on the motor drive when steam is first cut into a full coke drum. 

Dirt in the compressor rotor. This can be a big problem in dusty environments. Compare the observed head-capacity characteristics of the compressor against the performance predicted by the compressor curve. 

Air intake filters plugged Pressure restriction of blower discharge Increased ambient temperature Compressor rotor fouled Blower turbine running slow Wet gas compressor problems Fractionator condensers plugged... 

A schematic diagram for a simple-cycle, two-shaft gas turbine is shown in Fig. 6.54.The low-pressure or power turbine rotor is mechanically separate from the high-pressure turbine and compressor rotor. This unique feature allows the power turbine to be operated at a wide range of speeds, and makes two-shaft gas turbines ideally suited for variable-speed applications. 

However, this power loss is just the power delivered to the rotor of the compressor. This power comes from an electric motor, which has an efficiency of less than 1, and there are also losses in the connecting shaft and the bearings of the compressor rotor. If we express the combined efficiency of the motor and drive system as r m, then Ihe electrical power used will be greater than the compressor power by a factor of I/rjm, and so there will be a loss of electrical power given by the equation... 

Figure 9.2 (a) Typical centrifugal air compressor rotor and (b) model of twin screw Lysholm compressor. 

Fig. 5.30. Step-by-step view of the compression process within a screw compressor. Shaded portion represents one volume of gas as it passes through the compressor (diagram courtesy of Sullair). (a) Refrigerant is drawn axially into the compressor rotors as they turn past the intake port in the housing, (b) The rotors have now turned past the intake port gas is trapped in the compressor housing and rotor cavities. (c)As the rotors continue to turn, the lobes reduce the volume in the cavities to compress the trapped gas. (d)The process is completed as the compressed gas is discharged through the discharge port...

As the rotors are drawn past the intake port, gas is axially drawn into the compressor rotors (see Fig. 5.30a). As the rotor blades turn past the intake port, the gas becomes trapped, as in Fig. 5.30b. As the rotors push the gas forward, the cavities in which the gas is trapped become smaller (see Fig. 5.30c). Compressed gas is then discharged into the exit port after the process is completed. 

Fig. A-42 A fouled compressor rotor from an engine in Brunei.

Example case history 1. A gas turbine s compressor rotor developed blade tensile stresses while in operation that would quickly lead to failure. The OEM specified that a glass-bead peening process needed to be conducted all over the surface of the... 

---