Single-Stage Circuits

P-type manifold—veiiical configuration. The P ring dryer (see Fig. 12-100) incorporates a single-stage classifier and was developed specifically for use with heat-sensitive materials. The undried material is reintroduced into a cool part of the dryer in which it recirculates until it is dry enough to leave the circuit. 

Gives very clean sands and has relatively low hydraulic water requirements (0.5 t/t underflow). One of the most efficient single-stage classifiers available for closed circuit grinding and washing. Relatively expensive. 

FIG. 20-43 Single -stage closed-circuit wet-grinding system, [Tomy, Pit Quarry Tehixiaiy-March 1.9,59),]... 

The mills in the western United States, in which generally are ground softer talcs than those of New York, have simple flow sheets. Single-stage crushing is employed, and the talc is merely ground in Raymond roller mills in closed circuit with air separators. 

Figures 20-43 to 20-44 illustrate single-stage and two-stage closed-circuit wet-grinding systems. The circuits or Fig. 20-59 may also be used as a closed-circuit wet-grinding system incorporating a hquid-solid cyclone as the classifier.

Fig. 4.1-28. Single-stage canned-motor centrifugal pump (HERMETIC) 1, Impeller 2/3/4, Cooling circuit 5, Canned motor.

In high-pressure circuits, centrifugal pumps are used to overcome the pressures encountered in the pipeline and in the system, such that at lower pressure heads they are usually employed as single-stage pumps (Figures 6 and 6.1). At fluid temperatures of up to 180°C, self-cooling motors ofinsulation class H are employed. 

This circuit is therefore a scaler, in which the output is simply the inverted input multiplied by the factor (Rf/Ri). By choosing precision resistors, (Rf/RO can be set at any desired value, although the practical ratios for a single stage lie between 0.01 and 200. When Rf = R, the circuit is an inverter. 

The main circulation pump (pump) is intended for providing the sodium circulation in primary circuit. The pump is centrifugal, vertical arrangement, single-stage, console, sealed, electrically driven type. Motor — asynchronous, double-speed, vertical arrangement with squirrel-cage rotor. 

The primary circuit blower consists of a single-stage radial compressor. A speed-controlled asynchronous motor is provided as drive. The motor is cooled with water. The blower with motor is installed in the blower pressure vessel section as a slide-in unit with vertical shaft and hanging impeller. A blower flap is located on the suction side of the blower. The blower increases the pressure of the helium sucked in from the steam generator outlet side by approx. 1.5 bar. 

Power ampliher bandwidth is restricted by the equivalent load resistance across the parallel tuned circuits in the stage. Tuned circuits are necessary to cancel the low reactive impedance presented by the relatively high input and output capacitances of the amplifying device. The bandwidth for a single tuned circuit is proportional to the ratio of capacitive reactance Xc to load resistance Ri appearing across the tuned circuit... 

Single-stage reduction means that the material is reduced to the desired product fineness by the action of just one machine, which may operate either on the open-circuit (single-pass) or the closed-circuit principle (Fig.1). Multistage reduction is effected in two or more machines in series, each of which constitutes one stage of the reduction process and which operates either in open or in closed circuit. 

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