Material Elevator

[freerangequark]

Hi,

I am working on a project in which I need to elevate batches of coin (approx 3000 asst coins per minute_ approximately 36", along a patch which preferably within 20 degrees of vertical. The footprint of whatever method I choose needs to be kept to a minumum

Three methods I am currently exploring are:

1. Bucket Elevator
2. Cleated conveyor
3. Vertical Screw Conveyor

Is anyone here familiar with vertical screw conveyors? Based off what I can tell, it seem that this would be unsuited for batch processing because it requires continuous material feed to allow the elevator screw to funtion. Can someone verify this?

Can you think of any other methods I may want to consider.

Thanks,
Glenn




Are

 

[BWAppliedKinetics]

1. Good for large batches with longer spaces in between. May require integration of a slightly more complex control system to start and stop the bucket more precisely, or a dump and accumulate strategy.

2. Depending on flow rate can be continually running, no space required between batches. Again, may need an accumulator at the top. There are usually strict limits to both weight and angle (most, but not all, will not actually go vertical, more like 30-60 degrees). These can be made for low cost.

3. A vertical screw with the correct pitch and friction coefficient could work, you can even put cleats on it if you want. The main concern I would have is the cost of the screws and the implementation. With these you can go vertical in a relatively small foot print.

Other. Conveying has been around for a long time, there are lots of interesting ways to do things. It realy comes down to 3 things.
a) what form is the product in before conveying (ie is it coming freely off of a belt, is it in a bin on a belt, is being placed by hand...)
b) what form does it need to be in after conveying (ie into a bin, onto a conveyor...)
c) what are the proccess contstraints (is there a foot print limitation, how high do you need to go, what is the speed and accuracy required, are there chemicals or water present...)

Brad Woodward

http://www.akeng.com

http://www.appliedkinetics.ca

 

[freerangequark]

The coins would be fed by being dumped into a hopper which then feeds the belt or screw. After being elevated, they would gravity feed down a short chute into the sorting/counting mechanism. The total rise of the screw or conveyor would be about 36". I need 100% of the coins that get dumped in to get discharged at the top for sorting. I have some flexibility in the footprint, but at the moment, the footprint envelope allowed is around 10" x 20".

Thanks,
Glenn

 

[PeterCharles]

I've made a vertical screw lift elevator in the past and they're difficult animals.

I think I'd look at a steeply inclined belt conveyor with a cleated belt, or a vibratory spiral elevator.

 

[BWAppliedKinetics]

Given that you have some flexibility with foot print and you will be dumping into a hopper a cleated belt is probably the cheapest and easiest to implement option. Vibratory feeds are really good if you absolutely need to have the components aligned and your through put is low (ie bolt feeders etc) otherwise they are usually not worth the extra cost and effort (though again they can have a small foot print)

Brad Woodward

http://www.akeng.com

http://www.appliedkinetics.ca

 

[berkshire]

If you have a receiving tray or hopper at the top to even out the flow, a cleated belt running at an angle up to 80 degrees will work just fine.
Screw conveyors have a nasty habit of getting coins stuck between the screw and the case which does not do their appearance any good.
Is this a coin sorter, or a coin wrapping machine?
B.E.

 

[freerangequark]

This is on a coin sorter. With a curved cleated belt, I could run bellowed sidewalls or perhaps some UHMW guides to laterally contain the coin.

Thanks,
Glenn]

 

[berkshire]

Back in the early 70's I worked for a coin wrapping company making coin wrapping machines. We used a cleated flat belt running the full width of the machine inclined at 75 degrees, with close fitting uhmw guides on the sides of the belt to prevent spillage.
A Syntron vibratory feeder fed the coins onto the belt and leveled the pile for a more even feed.The boot of the elevator was designed to be self cleaning.Dropped coins being picked up by the returning cleats.
B.E.

 

[Ross0684]

Glenn
Have had no exposure to screw conveyors for coins, but from experience with other types (belt/bucket) feel there would be issues with screws.
Other comments from respondents are all valid, but I would have a preference for cleated belt with flexible bellow type sidewalls-downfall of these type of sidewalls is the required pulley diameters.
Vibratory feeders with speed control allow for trimming of flow for optimum results.
If using belt with cleats and side walls, prior to coin pick up point, run the belt thru a tunnel with minimal clearances,the length of the tunnel needs to be a minimum length equal to the pitch(centres) of the cleats-this normally ensures that there is no spillage.
Additionally, make sure the belt manufacturer spaces the cleats correctly and extends the cleats into the bellows of the side walls to minimise gaps
Also at the lower end of tunnel, provide a curtain ( flexible type flaps) so that conveyor belt has to pull through this curtain.
There is no hard and fast rule, but be prepared for a bit of R and D on the go to get it correct.
Good luck
Ross