it, and to protect the Cone Sleeve journal surface of the screw shaft. Sometimes the bushing
is lubricated with liquid from the material being pressed, such as the juice from apples or
water from pectin peel. Sometimes there is a grease fitting provided for lubricating the
bushing or to minimize leakage of press liquor through the cone bushing.
Bushing lubrication is extremely important when materials that are dry (like paper mill
screen rejects) are being pressed. By the time such materials reach the discharge of the press,
they do not have enough free moisture left in them to adequately lubricate the cone bushings.
Similarly, in some applications the cone is relatively stationary, rarely moving in or out. In
these applications the operator should, at the start of each shift, pump grease in until it comes
out between the cone bushing and the screw shaft. Then he should open and shut the cone
three times in order to spread the grease over the cone sleeve.
Rarely, presses are supplied with additional lubrication fittings so that water, in addition to
grease, can be metered to the bushings as a lubricant.
Automatic grease systems are available but only usable for fixed cones, a rarity for the KP-6
- KP-16 presses. These should be the high pressure (900 psi) electric or battery variety.
Vincent provides these for critical applications, especially pulp & paper.
Liquid leaking past the cone bushings drains out the back of the cone (at the air cylinder end
of the press). Almost always it is minimal compared to the flow of press cake.
Four-Bar Mechanism
Recently, a new discharge mechanism has been added. Its design eliminates the cone
bushing. This is typically used for applications where the material fed to the press is fairly
dry. With abrasive materials that sometimes get between the cone bushing and screw shaft,
causing issues, the four-bar mechanism has proven very effective.
Discharge Spout / Spin Stop
The press cake emerges from the end of the screen through a discharge spout, bolted to the
C-plate. If a press tends to jam, it may be necessary to shorten this spout. There is usually a
bar, called a Spin Stop, welded inside this spout. This will prevent cake from co-rotating
with the screw. There is a tendency for this to happen when the rotating cone feature is in
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