Chip Handling
Receiving
Raumaster chip receiving systems provide a reliable and efficient system for fully controlled purchased chips flow. Systems are always custom-made for each customer, keeping in mind the requirements set by the chip transport methods and the pulping process. A large capacity range is available due to a wide selection of equipment.
Purchased chips form a significant share of fiber raw material supply at many mills.
Purchased chips have to be carefully handled to maintain their valuable fiber properties. Raumaster chip receiving systems are available for chips transported by different methods including trucks, trains and ships.
Chip trucks may be self-discharging or tipping – with side or back discharge. Various alternatives are available to meet all needs.
Depending on required capacity as well as volume and shape of receiving pocket Raumaster chip receiving systems can be equipped with heavy duty chain reclaimers, traversing screw reclaimers or stationary feeder screws.
Typically, our chip receiving systems also include a scalper screen for separating oversized particles and a metal separator. Sampling systems and chip classifiers, available in online or offline versions, are offered as options.
Screening
Chip screening ensures the optimised chip size distribution for the pulping process.
The purpose of chip screening is to form the optimum chip size distribution for the pulping process. Modern mills typically use a thickness screening process because this has a large influence on cooking results. Increased yield, decreased rejects, lower kappa number, lower alkali consumption and better pulp strength are just some of the benefits of properly controlling chip thickness.
We offer complete chip screening systems for both thickness screening and conventional screening:
Scalper screens
Disc screens
ScreenMaster thickness screens
ScreenMaster fines screens
Gyratory screens
Stone separators
Metal separators
Chip Improvers
ChipMaster re-chippers
SliceMaster chip slicers
Laboratory classifiers
Both mechanical and chemical pulping processes achieve benefits by fines removal and pin chip control. The elimination of fines from wood chips improves pulp strength and quality
while simultaneously reducing chemical use. Two fundamental performance objectives of a thickness screen are to provide high overthick removal efficiency and minimize the carryover of accept chips.
The ScreenMaster thickness screen provides a superior solution to meet these process requirements. Effective chip flow agitation, high overthick removal efficiency and high selectivity are achieved using a special disc construction and a combination of three disc diameters. The proven screen construction offers low space requirement, low power demand and easy maintenance. Thanks to a special steel alloy and hard facing the wear of the discs is extremely low.
The ScreenMaster fines screen provides excellent fines and pins removal efficiency combined with minimal acceptable fiber loss. Because there are no overlapping parts in the adjacent screen rolls, fiber-destroying crushing action does not appear between the rolls. The roll diameter is large enough to enable powerful chip flow agitation which is prerequisite to effective fines removal at high infeed capacity. The screen is equipped with a variable speed controller, which allows adjusting the fines removal efficiency and selectivity while the screen is operating.
In chemical pulping the most favourable way of treating overthick chips is to use the Chip Improver. The pulpability of overthick chips is improved efficiently by a gentle destructuring action producing only a minimum of fines and pins. The simple construction with shaft-mounted drives needs very little maintenance.
For mechanical pulping the ChipMaster series re-chippers and the SliceMaster series chip slicers offer a rugged machine for oversize chip treatment utilizing modern chipping geometry.
Storage
Raumaster’s chip handling product line comprises an extensive range of chip storage systems and equipment including silo systems, pile storage systems, stacker & reclaimer systems, belt stackers, shuttle belt conveyors, traversing screw reclaimers, rotating screw reclaimers and conveyor systems.
Chip storage is an essential component of the pulping process. The main purpose of chip storage is to act as an inventory buffer against uncertainties of weather or inconsistent wood delivery. A properly designed chip storage system provides routine chip turnover, which dilutes the effects of periodic chip problems.
Raumaster's wood handling product line includes a comprehensive selection of chip storage systems and equipment, such as:
silo systems
pile storage systems
stacker/reclaimer systems
belt stackers
shuttle belt conveyors
traversing screw reclaimers
rotating screw reclaimers
conveyor systems
Typical solutions at modern mills are multi-silo systems with rotating screw reclaimers as well as open pile storage systems with shuttle belt conveyors and traversing screw reclaimers.
Advantages of a silo system are first in – first out principle as well as absence of climatic problems like wind separation, sunlight, snow and ice. In pile storage systems the whole pile can be automatically reclaimed if it is equipped with side walls. An efficient homogenising effect is achieved by using several reclaimers simultaneously under one pile.
Our screw reclaimers represent the state-of-the-art technology in the field of chip handling. Raumaster’s extensive experience in developing screw reclaimers has resulted in extremely reliable heavy-duty constructions. The effective reclaiming area of our screw reclaimers is superior compared with conventional reclaimers.
Our screw reclaimers can be equipped with an advanced control system which acts as a safeguard for the screw in overload situations and optimises the travel speed or rotating speed of the reclaimer.
In automatic storage systems advanced control and process optimisation systems developed by our automation department are used to ensure flexible and efficient operation.
Conveying
A complete range of conveyors for wood chips, bark and fines is available from Raumaster, including:
Screw conveyors
Belt conveyors: trough, flat and tubular variants
Chain conveyors
Elevators
