Widely considered the 'bees knees of conveyors', DRAG CHAIN CONVEYORS work on the principal of a chain and paddle combination pulling a volume of grain along. They are also called 'en masse' conveyors which is roughly translated as 'on mass' because that is how the grain is moved. Unlike a screw conveyor which churns the product around (the result is a vast increase in friction and therefore power required to drive the unit), a drag chain conveys the grain in a relatively single mass of product with the friction being reduced as only the grain at the extreme outsides (left, right and bottom of the unit) is touching on the conveyor housing.
The chain is a complete loop and is commonly bushed chain from 4" to 8" pitch with integral side paddles on every outer chain link. On these paddle we fit POLY STONE ULTRA plastic flites ('C' section strips of plastic) that has a very low coefficient of friction with the steel housing of the conveyor. The chain is driven by large specialized sprockets and has a typical linear speed of 0.5 meters per second.
As a result of the small frictional load on the conveyor typical power requirements are 1/2 to 1/3 of that required for a comparative screw conveyor. Couple this with the low wear rate of these units (when compared to a screw conveyor) and the fact that they arguably the 'softest' unit to move grain (very low crackage rate) and you can begin to appreciate how universal and reliable they are.
When priced against conveyors like screws and belts a DRAG CHAIN may seem expensive. The trade offs here are :-
- The longevity of the unit due to the low friction and wear,
- The gentle grain handling abilities due to the lack of grain churning and product crushing between flites and walls,
- The low power consumption due to the low frictional resistance of the grain on the conveyor housing and
- The ability to load at the ends and intermediate positions, the ability to unload the unit at any location along the units length and the ability to have an incline (kick up) or a decline (kick down) in the conveyor.
Common unit widths are 200 mm (8"), 250 mm (10"), 300 mm (12"), 350 mm (14"), 400 mm (16") and custom sizes up to 600 mm (24") wide. Common chains range from 3400 kg (7500 lb) up to 22700 kg (50000 lb) breaking strain. The plastic paddles are made from UHMWPE (Ultra High Molecular Weight Poly Ethylene) which has the characteristic's of low frictional drag and high wear.
Don't hesitate to call and ask about or range of DRAG CHAIN CONVEYORS.
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