Rotor diameter

Rietz disintegrators are normally supplied in rotor diameters from 10 to 60 cm (4 to 24 in), with rotational speeds to produce hammer tip speeds in ranges of 300 to 6700 m/min (1000 to 22,000 ft/min) and power ranges from 0.4 to 1.50 kW (V2 to 200 hp). Higher speeds and higher power are available. AC variable-frequency drives can eliminate belts and provide easier variation of speed. Models are available... 

Shutdown speed = 20 m/s Rotor diameter including hub = 39.35 m Rotational speed of the rotor at the rated wind speed = 38 r.p.m. 

A eompressor fully equipped with 80% blading reaetion turns at a slower speed than one with 50% reaetion having the same rotor diameter. This offers flexibility in matehing the various turbomaehines in nitrie aeid trains, whieh often have different optimum speeds. This flexibility often allows eliminating an intermediate gear without saerifieing effieieney. 

Rotor diameters, or quasi journals, include dimensions ranging from 14 mm (0.55 in.) to 600 mm (24 in.). Similarly, the load range accommodated by radial magnetic bearings is 0.3 N (0.007 lb) to 200 kN (45,000 lb). Rotational speeds range from a virtual standstill to as high as 800,000 rpm. 

The displacement of the screw compressor is a function of the interlobe volume and speed. The interlobe volume is a function of rotor profile, diameter, and length. Table 4-1 provides some typical rotor diameters and corresponding L/d ratios. The interlobe volume can be expressed by the following equation. 

Table 4-1 Rotor Diameters with Available L/d Ratios...

Volumetric efficiency is determined by the leakage at tips of the lobes. The leakage is referred to as slip. Slippage is a function of rotor diameter, differential pressure, and the gas being compressed. 

For the past few decades, manufacturers have been streamlining components and installing onboard computers to hit the propeller blades for maximum efficiency for the wind conditions. In the 1980s, the average turbine was 20 meters high with a 26-kilowatt (kW) generator and a rotor diameter of 10.5 meters. A typical turbine today can be 55 meters high, with a rotor diameter of 50 meters and a capacity of 1.6-MW. The power it produces may supply 500 homes. 

The underflow channel or channels in each quadrant should be either a single open channel or a series of holes next to the outer wall of the rotor. The underflow area should be as large as possible so that the effect on contactor performance is minimized. From ANL experience with contactors ranging from 2 to 25 cm in rotor diameter, the total underflow area for all four quadrants should be 5.8% of the outside diameter of the rotor squared. 

In liquid-liquid contactors, pressure drop is defined by the light phase. The heavy phase enters at near atmospheric pressure and is accelerated by the rotor to its discharge pressure. The pressure drop of the light phase is a function of phase density difference, rotor speed, rotor diameter, and location of the principal phase interface (24). 

---