Rotary seal

Lever and Shaft Mechanisms In pressurized vessels, float-actuated lever and shaft mechanisms are frequently used for level measurement. This type of mechanism consists of a hollow metal float and lever attached to a rotaiy shaft, which transmits the float motion to the outside of the vessel through a rotary seal. 

Estimate acceptable air leakages resulting from leakage around static and rotary seals, valves, access ports, and other items of mechanical nature required for process operation from the following equations and the specific leak rates 0 indicated in Table 6-8, which is based on w < 10 lb/hr. 

For equipment with rotary seals allow additional 5 Ib/hr for each conventional seal (packing type) and 2 Ib/hr for each mechanical seal and O-ring. 

The low-g rotor, which is shown in Figure 20.11, consisted of a rotating disc, fitted with two straight horizontal columns. The rotor, fitted with a rotary seal, was contained... 

Pumps are standard bronze centrifugal pumps, except those in vacuum service, which have double rotary seals. 

Summary and Forecast. The incidental mechanical difficulties, inseparable from a first model of a device—in this case chiefly rotary seal leakage—should be readily correctable. The depression of yield of the still to 30 to 35% less than design maximum is accounted for quantitatively by gross inleakage of air, presence of sea water semi-... 

The wormshaft can also be water cooled. The central shaft holding the worms is bored and a tube is inserted. Water passes through a rotary seal, then flows through the bore in the shaft toward the feed end, and then out through the inserted tube, and finally exits through a second port in the rotary seal. The water draws heat from the hottest part of the shaft and distributes some heat to the cooler part (by the inlet). 

Ito, Y. Cross-axis synchronous flow-through coil planet centrifuge free of rotary seals for preparative counter-current chromatography. Part I Apparatus and analysis of acceleration. Sep. Sci. Technol. 1987, 22, 1971. 

The nonsynchronous flow-through CPC is a particular type of planetary centrifuge which allows adjustment of the rotational rate of the coiled separation column at a given revolution speed. The first prototype was equipped with a dual rotary seal for continuous elution. Later, an improved model " was designed to eliminate the rotary seal which had become a source of complications such as leakage, contamination, and clogging. 

Fig. 11 Improved nonsynchronous flow-through coil planet centrifuge without rotary seals, (a) Cross-sectional view through the central axis of the apparatus (b) photograph of the apparatus equipped with an eccentric coil assembly. (From Ref. [14].)...

In general, the retention of the stationary phase in the coil rotated in the unit gravity field entirely relies on relatively weak Archimedean screw force. In this situation, application of a high flow rate of the mobile phase would cause a depletion of the stationary phase from the column. This problem can be solved by the utilization of synchronous planetary centrifuges, free of rotary seals, which enable one to increase the rotational speed and, consequently, enhance the Archimedean screw force. The seal-free principle can be applied to various types of synchronous planetary motion. In all cases, the holder revolves around the centrifuge axis and simultaneously rotates about its own axis at the same angular velocity w. 

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