Opening bowl centrifuge

FIGURE 3.4-9 Decanter solid-bowl centrifuge with cylindrical-conical rotor ad open liquid onllet. Courtesy of Alfa-Laval Inc,... 

Fig. 11.15. Diagram of a continuous centrifuge with automatically opening bowl for regular removal of the lees 1, feed 2, clarified liquid outlet 3, sediment outlet...

FICURE 3.4-7 Solids-ejecting solid-bowl centrifuges (a) the bowl is closed hydraulically and (6) the bowl is opened hydraulically during the partial discharge of solids only. Courtesy of Alfa-Laval Inc. 

Alfa Laval-Sharples also manufacture the AS-26SP tubular bowl centrifuge. The AS-26SP has all the features of the AS-16VB but in addition the drive shaft is sealed with a triple mechanical seal. This centrifuge can be steam sterilised before and after operation without opening it to the atmosphere. The manufacturers claim that these... 

The most common of the continuous-flow centrifuges are the industrial or pilot plant open bowl units. Some of these centrifuges are over twenty years old but are still quite serviceable. Their drives operate on air or steam turbines, or by electric motors. Many units have refrigeration coils in the bowl to keep the product cool during centrifuging. The process... 

Figure 7.10 Opening bowl disc-stack centrifuge...

Variable-speed basket centrifuges rotate on a vertical axis. The cyhndrical perforated basket, connected at one end to a bowl head or hub, is driven from below or suspended from above by a driveshaft. It is capped at the other end with a weir ring. The hub may be a solid piece or with an annular opening. If the hub is a sohd piece, the shiny is introduced into the basket at low speed despite the fact that the earths gravity may influence the annular pool. The settled sohds can be removed from the top only when the machine is at rest. Otherwise,... 

Another type of disc centrifuge has nozzles or orifices at the periphery where thickened solids are discharged continuously, and sometimes a fraction of this discharge is recycled to ensure that the nozzles are able to prevent breakthrough of the clarified supernatant liquid. Sometimes these nozzles are internally fitted to the bowl. Others are opened and closed electrically or hydrostatically from a build up of the sludge within the bowl. 

The Rotosil process employed by Heraeus and Heraeus-Amersil is used for the production of tubular or cylindrical shapes. It permits greater uniformity and dimensional control than the previous process. The quartz is washed in hydrofluoric acid and distilled water to remove impurities which can promote crystallization during manufacture. The sand is then placed in a rotating horizontal steel tube where it is held at the circumference by centrifugal force. A carbon arc is passed slowly down the center of the drum to fuse the sand. A modification, using open rotating molds on a vertical axis, allows formation of cmcibles, beakers, and bowls. 

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