ALFA LAVAL || how to work PX Separator ALFA LAVAL

[Music] during separation solids collect at the wall of the bowl and we need to periodically discharge a meter remark discharge can only be made by reducing closing pressure of the operating water under the sliding ball bottom this is done by allowing some of this water to escape through these drain pools they are closed off by the plugs attached to the operating slide which is being forced up by the coil springs or hydraulically in some systems the valve in the opening line is open injecting water into the space above the operating slide called the opening chimney the water is thrown by centrifugal force to the periphery of this space [Music] this nozzle allows some of the water to continually Escape but since the quantity of water being supplied is greater than the amount of water escaping through the nozzle the water forms a level and starts to fill inwards [Music] the great pressure produced by centrifugal force on the water means that only a small level of water will produce sufficient Force to overcome the comparatively leaked coil springs the drain holes open slightly allowing the operating water under the sliding ball bottom to escape into the chamber this extra water flowing into this chamber causes the level to fill in at a faster rate [Music] and although the control system has closed the valve in the opening line the water which previously held the sliding ball bottom up now helps to press the operating slide down reinforcing the downward opening force on the operating slide foreign water is now draining out from under the sliding Bowl bottom the level moves outwards reducing the upward closing force on the sliding Bowl bottom when this Force drops below that of the downward opening Force the sliding ball bottom drops [Music] uncovering the discharge ports [Music] meanwhile the operating water escaping into the opening chamber continues to fill inwards and rapidly overflows into this chamber called the closing chamber the closing chamber also has a small draining nozzle [Music] this chamber quickly turns inwards creating an upward closing force on the operating slide at the point where the combined forces of water under the slide in the coil springs exceeds the opening downward force of the water above it the slide will be forced up sealing the drain holes of the space under the sliding Bowl bottom [Music] the opening chamber and the closing chamber continue to drain both have the same size drain nozzles and will drain at the same rate maintaining the closing force on the operating slide the drain holes in the space under the sliding ball bottom are closed the level of the water moves inwards Supply from the static header tank situated at around three to four meters above the bowl [Music] this increases the closing force on the sliding ball bottom until it becomes sufficient to overcome the opening force of the processed liquid above the sliding Bowl bottom pulls up closing off the discharge ports the level continues to fill inwards until it touches the pairing disc in the pairing disc chamber the action of the disc on the rotating water reestablishes the equilibrium in the operating system and the ball remains closed until the next shot [Music] let us look at the complete cycle once more the contents of the bowl are undergoing separation the clarified liquid is entering here okay the heavy phase is separated from the light phase heavy phase is pumped away here and the light phase here solids build up of the bowl periphery [Music] when it is time to discharge the solids the interface between the liquid phases is repositioned by closing the water Outlet valve and opening the water supply valve [Music] interface smooth [Music] the valve in the opening line is opened and the opening chamber fills in the downward force on the operating slide overcomes the coil springs and the slide drops uncovering the drain holes for the space under the sliding Bowl bottom the operating water under the sliding ball bottom rapidly fills the opening space the valve in the opening line closes while the level in the space under the sliding ball bottom has moved outwards inducing closing force allows the sliding ball bottom to drop uncovering the discharge ports the water in the opening chamber overflows into the closing chamber and fills in the upward closing Force exerts on the operating slide plus the force of the coil springs seal the drain holes with a space under the sliding Bowl bottom [Music] whilst the opening chamber and closing chamber continue to drain at identical rates the level in the space under the sliding ball bottom is replenished by the static head Supply the level moves inwards until the resultant increase in the closing Force forces the sliding ball bottom up against its seal closing off the discharge ports foreign [Music] disc chamber fills in until the pairing disc and the static head re-establishes equilibrium [Music] 's charge period is determined by the time taken of the operating water leaving the space under the sliding ball bottom to overflow and fill the closing chamber sufficiently to force the operating slide up closing these drain poles [Music] water has to fill namely the closing chamber on certain models the volume of the closing chamber may be adjusted by selecting suitably sized filler rings [Music] so that for each chamber volume an exact solids discharge period is achieved for each and every shot thank you [Music] we have seen that a total discharge is affected by a series of partial discharges here we see the rotating ball has been prepared for empty the light phase has been displaced by the water and the feed turned off first a series of discharges is initiated and this results in a fixed amount of water escaping from under the sliding lower bottom and the level moves out to this point allowing sliding ball bottom to drop [Music] the level of the liquid in the bowl will move outwards reducing the downward opening force on the sliding ball bottom when this Force becomes less than the upward closing force of the operating water the sliding bore bottom will move up closing off the discharge ports [Music] the operating water must be prevented from returning to its equilibrium level in the pairing disc chamber since the next discharge cycle will simply cause the level of the operating water to return to this same point if we shut off the valve in the closing line the operating water will not be topped up next discharge period will cause this level of operating water to move further out along the space [Music] sliding bowl water will now drop [Music] the ball moves out until the reducing opening force it exerts on the sliding ball bottom again drops below the upward force of the operating water this cycle is repeated until the bowl has been completely empty [Music] we have of course been looking at the discharge cycle in very slow motion in real time the complete cycle takes only a tenth of a second from start to finish [Music] okay