A gear has space between the teeth. If it turns inside of a circular container the spaces turn. An opening at the top allows material to fill the space and the gear turns. An opening at the bottom allows material to fall out of the space. Each space must be large enough to qualify as a volume measure for the material. So maybe a hub with dividers that holds 100ml each turn and a stepper motor turning the wheel stop and go. Or maybe 1 deep cup in a small wheel that turns 360 deg to load and dispense 1 measure?
ijoin:
Any one can suggest how to stop the flow efficiently ?
you could possibly use a servo motor to trigger when a certain weight sensor detects the weight of the bag at 950 grams (so it has time to shut of). If you modified the blade of the servo you might be able to stop the flow at the exact time.
Auger will be my last option since it's harder to build and maintain
GoForSmoke:
Leave some clearance in tubes/transports and put a shaker on it helps move things along. Shaker is DC motor with off-center "flywheel".
Compressed air could stop rice falling down a tube.
Good idea, will try to look more into it
saildude:
An auger might work - but the design and clearances would need to be such that it would not jam or break the individual grains.
A slide gate might also work - use air for quick actuation
But issues balancing speed of fill and accuracy no matter what method is used. Suggest a bit of searching to see how commercial fillers work -
Yeah, the only problem is auger tends to break the grain
I will use butterfly valve to close the flow
Death_Pacito6:
you could possibly use a servo motor to trigger when a certain weight sensor detects the weight of the bag at 950 grams (so it has time to shut of). If you modified the blade of the servo you might be able to stop the flow at the exact time.
GoForSmoke:
A gear has space between the teeth. If it turns inside of a circular container the spaces turn. An opening at the top allows material to fill the space and the gear turns. An opening at the bottom allows material to fall out of the space. Each space must be large enough to qualify as a volume measure for the material. So maybe a hub with dividers that holds 100ml each turn and a stepper motor turning the wheel stop and go. Or maybe 1 deep cup in a small wheel that turns 360 deg to load and dispense 1 measure?
use pressurized air to blow across the opening of the gravity feed grain source pipe. This will create a vacuum in the pipe to help with gravity to move the grain down the pipe, as well as clear the "nozzle" of any irregular grain.the pressurized air can move the grain horizontally to a larger exit pipe and the air can be exhausted at one end of the horizontal pipe, which can have a air filter that can be removed to access for clearing jams and maintenance. A solenoid can control the air flow and when there is no air, the grain will build up in the horizontal pipe and stop the flow.
You could also squeeze the outside of the feed tube if the wall of the tube is soft, we did something like that with a valve that was shaped like a spool and we put air on the outside of the valve. Maybe a second tube at 90 degrees to the feed tube and inflate the second tube to shut off the flow.
ijoin:
Auger will be my last option since it's harder to build and maintain
Good idea, will try to look more into it
Yeah, the only problem is auger tends to break the grain
I will use butterfly valve to close the flow
ThanksThanks, good idea and insight
In the end, I think i will use butterfly valve
Your heading was " Best Way to Stop Grain Flow for Filling Machine" and further in your original query was " Any one can suggest how to stop the flow efficiently ?" ...hence the auger solution as that is the normal approach.
If that does not suit, that's fine but it does answer your query nevertheless.
With a butterfly valve, consider that the valve vane has to push falling grain ‘out of the way’.
This creates an extra variable load on the shutter mechanism.