Vessel stabilizing actions

These values make it evident that the contact angles must be observed rather carefully to obtain a value close to 90°. The following experimental procedure is practical to obtain good stability. A container with the particles is placed on the bottom of an oil-filled vessel with parallel walls, and a drop of the aqueous phase is placed on the powder. The shape of the droplet decides the action to be taken. 

Demulsifying agents are usually added to the continuous phase and need to diffuse to the interface and displace, or otherwise destroy, the effectiveness of the original stabilizing agents at the interfaces. The demulsifier should usually be added far enough upstream to permit these actions to take place, and for droplet coalescence to occur, before the emulsion reaches a separating vessel. Demulsifiers are formu-... 

We have thus far considered only those factors which can minimise any tendency of antifoam drops to cream, collide and coalesce. Collision may however result in the formation of only loosely bound flocculated drops. This does not of course represent a desirable product attribute even though such drops may be readily redispo sed by simply shaking the containing vessel. Moreover if those drops should subsequently coalesce, then redispersal by such means may be extremely difficult The concomitant loss of antifoam action may be permanent This situation is obviously to be avoided if possible by selection of appropriate stabilizing surfactants or polymers. However, little is apparently known at all about the coalescence of polyorganosiloxane-hydrophobed silica drops in the types of environment provided by detergent liquids. 

Let s consider the longitudinal metacentric stability of the vessel (Fig. 3) while developing the trim under the moment action caused by force Py applied to the deck in the vessel forward end... 

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