DESCRIPTION, OPERATION and
APPLICATIONS
of the
FULTON ROLL PRESS
Applications
Semi-Chemical
Chip Washing
Knots and Screen Rejects Pressing
Liquor Extraction From Pulp
Chip Pressing
Bark Dewatering
Other
Juice Extraction
Description & Operation
The Fulton Roll Press consists of three rolls (Top roll, Feed roll, and Discharge roll) mounted in two vertical housings and driven together at one end with semi-enclosed gears also crown wheels.
The rolls are made up of forged steel shafts on which cast iron sleeves, with machined circular grooves in the surface, are pressed on. The sleeves are made of special open grain cast iron, which retains the rough gripping surface during the life of the sleeves. The sleeves can be made of other materials to suit the specific application.
The roll shaft journals are supported in removable bronze sleeve type bearing boxes mounted in the housings.
The top roll is free to float or lift, acting against constant but adjustable hydraulic pressure.
The hydraulic pressure is applied to the rams and maintained uniformly at a pre-set working pressure by means of hydro-pneumatic type accumulators.
The opening, or nip, between the top roll and the bottom rolls can be changed by adjusting the rolls for different capacities and materials. If necessary the speed of the rolls can also be changed, by providing the press with a variable speed drive.
Between the two bottom rolls is a bridge plate which conveys the material going through the press from the feed roll nip to the discharge roll nip. the feed roll is grooved to mesh with the grooves in the feed roll and it fits snuggly against the feed roll. The bridge plate is set with certain clearances or openings in relation to the top roll.
The top and discharge rolls are provided with spring loaded grooved scrapers or doctor blades that mesh with the roll grooves and keep them clean.
The material to be processed is conveyed continually to an entrance hopper and fed into the press, passing through the nip between the top and the feed rolls where some of the liquid is extracted and the material fiberized to a certain extent.
The bed plate guides the partially prepared mat of material into the discharge roll nip where it is again squeezed to obtain further juice reduction.
The discharge nip is smaller than the feed opening nip and does most of the extraction.
The extracted juice or liquor drains into a pit under the press. The processed fiber material is delivered from the discharge roll into a chute and then conveyed into the process as required.
Semi-Chemical Washing
The Fulton Roll Press can be used for single or multiple stage pressing by adding water
between stages if desired. The liquor extracted in the first press is highly concentrated
and when the press is used ahead of a conventional washer, the load on the washing station
is greatly reduced.
Knots and Screen Rejects Pressing
The Fulton Roll Press is used successfully in extraction of black liquor from knots
and screening rejects, facilitating the handling of them by pneumatic systems . The
shredding obtained exposes the inner fibers of the knots to the liquor action. Savings of
15 - 20% in chemicals and 50% reduction in the recirculation have been reported.
Liquor Extraction From Pulp
The Fulton Roll Press is suitable for extracting liquor and concentrating different
types of pulp such as flax pulp, bleached pulp, Aspen bleached pulp, etc. This operation
is done prior to the washers, allowing the recirculation of highly concentrated liquor
through the system and reducing the load on the washing system.
Chip Pressing
Chips directly from the wood room or from the chip washers are pressed to expose the
inner fibers and to remove the excess water and shred the fibers as preparation for
feeding to the ground wood system. The stock coming from the digesters in high yield
systems can also be handled by the press to extract liquor prior to feeding to the
refiners.
Bark Dewatering
The press is also used for dewatering bark or hog fuel for burning. The press breaks down
the material in such a way that it can be easily blown without any further hogging
or
burning.
Other Applications
Although materials outlined above cover a wide-range, this is not the limit of use for the
Fulton Roll Press. Any fibrous material can be pressed, dewatered, or concentrated through
it's use. Pulp in drying systems, straw, bagasse from sugar cane, cane, rags, etc. can be
handled successfully and economically.
In any case it would be wise to send samples to the St. Louis facility of Fulton Iron.