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Difference between two types of log debarkes

Author:小编 Viewed:294 Publish data:2020-12-18 09:18:55

To help you make the best decision for your mill, we put together a short guide to log debarkers. 


1. Drum Debarker


Drum debarkers are an older technology developed for processing large volumes of lumber. It is an on-mass system, meaning operators feed multiple logs into the debarker and debark them simultaneously.  


Drum debarkers are composed of a large, rotating cylinder (the drum), the inside surface of which is equipped with ridges (“rifters,” “staves,” or “lifters”). As the drum rotates, the rifters lift the logs and cause them to tumble against one another. As bark comes off the logs, it exits the debarker through slits in the drum.


Drum debarkers are not mechanical debarkers, meaning the machine itself does not debark the logs. Friction produced as the logs tumble against each other does the debarking. The rifters may occasionally remove some bark, but they are not designed to cut.


We suggest producers consider the Drum debarkers for large-volume debarking.



DRUM DEBARKER ADVANTAGES


High capacity


Producers can feed in and discharge multiple logs


Produces a smooth surface finish in a wet process



DRUM DEBARKER DISADVANTAGES


Does not process small-diameter logs well


Does not do well with species that have stringy or difficult-to-remove bark


High costs and long downtimes for maintenance


Inconvenient for shipping



2. Roller Debarker (Rotary Debarker)


Roller debarkers debark logs using friction and mechanical means. Like drum debarkers, they are an on-mass system and can debark multiple logs at the same time.


Roller debarkers look similar to drum debarkers, but they operate differently. Like drum debarkers, they have a large tube through which the logs travel. This tube, however, is fixed; it is merely sidewalls and a cover. (Smaller roller debarkers may have open tops.) Inside the debarker are a series of rollers equipped with abraders. These abraders act like small hammers that “kick” logs as they pass through, forcing them to move up the side of the debarker until they reach the top and tumble back onto the pile of logs inside the debarker. While this is occurring, all the logs are tumbling against one another. The abraders also cut the log surface to start peeling the bark.


Like drum debarkers, the logs can be kept inside the debarker by closing a gate on the output side of the machine. If the roller debarker has a floor, bark leaves the debarker through slits. If the debarker has an open floor design, bark exits between abraders, which are designed to work as a screen.


ROLLER DEBARKER ADVANTAGES


Can debark logs with both small and large diameters


Can debark frozen logs


Can debark species with difficult-to-remove bark


Minimal fiber loss


High bark removal percentage


Reasonable capital costs


Less power required than drum debarkers


Variety of sizes available


Convenient for shipping


ROLLER DEBARKER DISADVANTAGES


Lower capacity than drum debarker


Won’t produce as smooth of surfaces as a rosserhead debarker


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