Horizontal-head centrifuge

The spinning rotor of a horizontal-head centrifuge offers considerable resistance to rotation and generates heat as a result of air friction. This resistance is lessened if the swinging buckets are enclosed in a windshield. 

The single-stage, horizontal, overhung, centrifugal pump is by far the most commonly used type in the chemical process industry. Other types are used where a high head or other special process considerations are specified. 

In the rotor of an angle-head centrifuge, tubes are held in a fixed position at angles from 25° to 40° to the vertical axis of rotation. Upon centrifugation, particles are driven outward horizontally but strike the side of the tube so that the sediment packs against the side and bottom of the tube with the surface of the sediment parallel to the shaft of the centrifuge. As the rotor slows down and then stops, gravity causes the sediment to slide down the tube usually a poorly packed pellet is formed. 

Horizontal centrifugal pumps should provide 150% of the rated capacity at 65% of the rated pressure, with a shutoff head of not more than 120% of the rated pressure. This pump should be used only when suction supply is under a positive head. Suction pipes should be designed to preclude the formation of air bubbles. A characteristic curve for a rated fire water pump is shown in Figure 7-15. 

Centrifugal compressors must operate on a curve, just like centrifugal pumps. A typical curve is shown in Fig. 28.3. The horizontal axis is actual cubic feet per minute (ACFM). This is analogous to GPM, used on the horizontal (x) axis of centrifugal pump curves. The vertical axis is H (poly tropic feet of head). This is analogous to the feet of head used on the vertical (y) axis of the centrifugal pump curve. 

It is supplied with a dual purpose head. The buckets can either swing out to the horizontal position or, by means of a rubber adapter, the buckets can be held at a fixed angle of 45° (M.S.E.) or 51° (International) in the latter case, the instrument acts as an angle centrifuge. This is an alternative to the hand centrifuge. 

Top Suspended Vertical Centrifuges A special type of top suspended centrifuge is widely used in sugar processing and is shown in Fig. 18-165. Conventionally, the drive is suspended from a horizontal bar supported at both ends from two A-frames. The drive head, which is connected to the motor or a driven pulley through a flexible coupling, carries the thrust and radial bearings that support the basket,... 

Static Head. Fluid elevation above or below the datum line. For horizontal centrifugal pumps, static head is calculated from the pump center line with vertical pumps, it is taken from the eye of the first-stage impeller. 

ProeeSB Pumps. Three 10,000-gpm 225-ft-head horizontal single-stage double-suction centrifugal pumps, each driven by a 700-hp motor, are... 

Fig. 3 Design of helix CCC (toroidal coil CCC) apparatus. A, Schematic drawing of centrifuge head of original helix CCC apparatus B, cross-sectional view of advanced design of helix CCC equipped with seal-free flow-through device. 1, Motor 2, toothed pulleys 3, toothed belt 4, stationary miter gear 5, horizontal idler miter gear 6, inverted upper miter gear mounted at bottom of column holder shaft (8) 7, gear box 9, column holder 10, coiled separation column 11, hollow tube support 12, flow tubes and 13, clamps.

Figure 6.5 The anaiogy between the static head in a gravity tank (a) and the centrifugal head in a hydrocyclone (b) (note that the hydrocyclone is shown with its axis horizontal)...

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