Belt conveyor in Indian Rice Mills are always been ignored. I have lot many reasons to like belt conveyors and hence I am sure that future of Belt Conveyors in Rice Milling Industry is very bright as it breaks no grain.
Let us review both the conveyor's application wise. In general, Belt conveyors are suitable where you have one or more than one input but delivery is required only in one single output, although there are belt conveyors that very effectively undertake the job of delivering to more than one outlet
Drag Chain Conveyor is more suitable for applications where Input is one but delivery is required in one or more than one output.
In rice mills people use Drag Chain Conveyors mainly because they are enclosed and are cheaper too. Since there are almost no supplier in india who make good enclosed belt conveyors in India hence it's usage in rice mills is generally discouraged.
However, Belt Conveyors have lots of advantages over Drag Chain Conveyor when we talk about conveyoing paddy or rice.
1. Belt conveyors are simple in construction and easy to maintain.
2. They donot break Rice grains because in Belt Conveyor Grain is always stationery on the belt not even frictional forces act on it. Whereas in Drag Chain Conveyor Grain moves alongwith the Chain and lot many frictional forces act on it while dragging it.
3. One can easily go for high conveying speeds i.e. as high as 3 Mtrs/sec in Belt Conveyors since the grain is staitionery, whereas in Drag Chain conveyors if you go beyond 0.5 Mtrs/sec Rice Brokens will increase a lot. Hence you can have belt conveyors with much smaller width giving same capacity as Chain Conveyor.
4. There are very few maintenance requirements in Belt Convyor as it does not break any Rice Grain and a few additional equipment like Zero Speed Switch and Belt Sway Switch can maintenance requirements can even be brought down to nil.
5. Cleaning requirements of belt conveyors are also very minimal as compared to drag chain conveyor.
However, the present design of belt conveyor must be upgraded to make it suitable for rice milling application.
A few upgradation requirements as as mentioned below;
1. Belt Conveyor should be fully enclosed, Self Cleaning Type and suitable for outdoor application
2. There should be no return roller and instead bottom deck should be lined with UHMWPE and Conveyor belt must have cleaning cleats to clean this UHMWPE lined bottom deck.
3. Tail end Roller must be equipped with Flippers to carry the material from bottom deck and transfer it to upper deck from conveying again.
4. Tail Roller must have Zero speed switch to check belt slip and stop the belt beyond a particular slip limit.
5. Belt sway switches must be installed at head and tail end to check if there is any misalignment of belt.
6. Grain feeding Inlets must be inclined at 45deg from the horizontal and must always have a rake and pinion gate assembly to control grain flow. Counter weight equipped, self openable type scrapers must be installed below each frain feeder to ensure smooth flow without grain spillage.
7. Head and Tail rollers must be equipped with replaceable laggings pads
I wish some material handling equipment supplier takes up challenge to develop this kind of Self Cleaning type Belt Conveyor for Rice Mills.
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