Silos - how do they work?

Mike Harding · Guru

Silos - how do they work?

Possum3 · Guru

found this [ borton.net/silo-construction/

woolman · Guru

There is an elevator. Series of paddles on a belt that take the grain to the top of the tower as the paddles goes over the top the grain is thrown out and gravitates into top of the silo. Bit more complex in design but that is the principle.

. Neil

Craig1 · Guru

Then Perce comes along and adorns them with some fantastic art work.

Ian G · Senior Member

As mentioned inside the tower is a bucket elevator ( a vertical conveyor belt with buckets attached roughly every 300 mm) The bottom of the elevator is several metres underground, there is a pit beside the elevator with a hopper and a grate capable of taking the weight of a truck. A farmer in his truck can pull up on the grate and tip his grain, the grain is transferred to the bottom of the elevator, lifted vertically, at the top of the elevator there will be a diverter valve which determines which silo will be filled. There is a similar setup for the outfeed of the silo to fill trucks or rail wagons. That's basically how it works . Ian

Southern Cruizer · Guru

Pretty sure if you were to visit the place and hopefully if there is anyone working there or knows someone who works at them they would be more than happy to explain the workings to you first hand. Better to come first hand than being passed down a dozen times by someone who thinks they know. Coming off a farm a few years back, have dealt with them over the years many times but trying to describe the workings without being able to show to a person visually being there is a bit harder to remember

Gundog · Guru

gold dandelion · Senior Member

Ian G, is pretty well on the money, also, a good job for anyone looking for seasonal work, also sampling and weigh bridge operator for the missus. (seasonal). you can strat in QLD and work your way down to Vic. if anyone is working there, although I doubt it they will show you around. next time you are in a bigger grain town drop in.

peter67 · Guru

Bugger how it works, needs a good artist to freshen it up.

DMaxer · Guru

Ian has nailed it. When I was at primary school we had a teacher that thought it was very important for us kids to see first hand how everything worked. He organised trips for our class and one of the trips went out to the countryside and we were shown over a working silo that was located next to the railway line in NSW. We were lucky as on the day we were there, trucks were unloading grain and then a train pulled in to load up so we got to see the whole show from start to finish.

Just off topic, we also had trips to Ford to see cars being built, a trip to Coca Cola to see it made and bottled, a trip to Garden Island to see HMAS Melbourne and the best one of all, a guided tour over a Qantas Boeing 707 and a sit in the pilots seat at Mascot.

Anyway, back on topic, these silos were all administered by the Grain Elevator Board of each state until about the mid 1990s.

-- Edited by DMaxer on Thursday 20th of April 2023 12:37:07 PM

Mike Harding · Guru

Thank you very much everyone for your replies, my journey of understanding is almost complete but a couple more questions:

What are the two tall "chimneys" for?

What is the process used to transfer grain from the silos to trucks/trains?

As suggested; I'd love a tour but whenever such things are suggested these days the words "healthy and safety" and "insurance" are usually uttered.

DMaxer · Guru

From what I recall the chimneys are used for ventilation and the removal of dust from the grain. They also used pesticides to control vermin and it gets rid of the fumes. The grain is conveyed up and then comes down through a loading chute or it did on the one we looked at.

Possum3 · Guru

DMaxer wrote:
From what I recall the chimneys are used for ventilation and the removal of dust from the grain. They also used pesticides to control vermin and it gets rid of the fumes. The grain is conveyed up and then comes down through a loading chute or it did on the one we looked at.

Vent tubes on top are to prevent vacuum block forming when emptying.

Dust is allowed to settle on grain when filling - very flammable and can be explosive in confined spaces.

They don't put pesticides with grain in silo (Poison) - they do liberally bait around them though.

DMaxer · Guru

Thanks for the correction Possum. I remember being told they put something in there to control the rats and mice.

Ian G · Senior Member

As D Maxer said the chimneys are for ventilation, when you are emptying the silos at a fast rate you have to replace the air otherwise you can create a vacuum and damage the silo, they will also have some sort of damper in there to cushion the grain as it changes direction at the top of the silo, otherwise the fast flowing grain would wear a hole in that area very quickly.
There will be a screw conveyor under the silo which will bring the grain out to another elevator, this can either just fill a truck and use the onsite weighbridge, or fill another bin called a garner bin, which is suspended on load cells.

Possum3 · Guru

Mike Harding wrote:

What is the process used to transfer grain from the silos to trucks/trains?

The smaller silo on left of photo, gravity. (note funnel shaped bottom), some are emptied using vacuum hoses - others use screw augers (lift pump).

Most grains are very fluid and like water - If a worker falls onto grain it is likely they will "drown".

The large circular structures in foreground silos are enclosed machinery and access platforms.

Ian G · Senior Member

Sorry Possum but I think the story of falling into a silo and drowning is an old wives tail, I've worked in the grain industry for 45 yrs, If I wanted to do some repairs to the inside of a silo I would fill it up so I have some thing to stand on, safety measures have to be taken, it's no different to walking over a heap of grain in a shed. Oil seeds might be an exemption . The issue is if the silo is being emptied, then the grain will quickly form a funnel and there would be no way of getting out of that, the air quality is also an issue. Ian

-- Edited by Ian G on Thursday 20th of April 2023 04:27:02 PM

Mike Harding · Guru

Ian G: thank you :)

Two excellent explanations. My lust for silo knowledge is now satisfied.

I can now look at them and think "I know, more or less, how you work." And that is very pleasing to me.

Thanks to all.

Possum3 · Guru

dailyyonder.com/grain-bin-accidents-and-deaths-rising-due-to-poor-crop-conditions/2020/06/10/

metro.co.uk/2022/07/05/boy-13-and-aunt-33-die-in-grain-silo-after-she-went-in-to-save-him-16943159/

www.abc.net.au/news/2019-01-09/sa-farmer-dies-falling-in-grain-bin/10701380

Ian G · Senior Member

Yes Possom all tragic stories, one was in a silo while it was being emptied, one fell in a silo while it was being towed and grain obviously being agitated and the other doesn't give all the circumstances, I agree silos can be a dangerous place and should never be entered for several reasons. Sorry to say "Most grains are very fluid like water - If a worker falls into grain it is likely they will drown "just isn't true, people walk on grain pulling tarps over grain bunkers, in the back of trucks, they don't sink like water, there will be more to the story if there is a tragedy. Ian

gold dandelion · Senior Member

I used to jump off the conveyor belt from a big height when a young fella, and an older fella, the most you would sink would be to your knees. Canola is a very different story, you can keep sinking there without much trouble(drown).

Ian G · Senior Member

Yes true, Canola or any oil seed has to be treated with respect, truck drivers will carry a roll of duct tape or similar and tape the back of there tailgate, if Canola starts to leak there is no stopping it.
I remember in the "old days" before aluminium tippers were the norm most gain was delivered on flat bed trucks with grain chutes ever 2 metres or so, the driver would open the chutes, stand on the grain and shovel it all out through the chutes, most of it ran out with gravity but it was still hard work, they would get some grain in there boots but that's about all. These days I doubt if there allowed out of there vehicle

Craig1 · Guru

I remember in the "old days" before aluminium tippers were the norm most gain was delivered on flat bed trucks with grain chutes ever 2 metres."

Also you needed " grain curtains ", which from my memory were mongrel plastic strips sewn to canvas sides. The strips laid on the boards and the weight of the grain held them down. BUT, Loading - you had to be there shoveling grain onto said placky bits at the start, so that was a 96 foot round trip pushing/shoveling grain, so everything all sat square and tight.

Ian G · Senior Member

Then they put hydraulics on the front of those trailers and called them convertibles.

gold dandelion · Senior Member

They seal all the Silo's and Bulkheads at the end of the season the keep them fumigated until they start outloading

Craig1 · Guru

Then they put hydraulics on the front of those trailers and called them convertibles.- Wrote Ian G

1st ones deleted two pallet spaces from memory, some unhappy chappies then.

yobarr · Guru

Ian G wrote:
Yes true, Canola or any oil seed has to be treated with respect, truck drivers will carry a roll of duct tape or similar and tape the back of there tailgate, if Canola starts to leak there is no stopping it.
I remember in the "old days" before aluminium tippers were the norm most gain was delivered on flat bed trucks with grain chutes ever 2 metres or so, the driver would open the chutes, stand on the grain and shovel it all out through the chutes, most of it ran out with gravity but it was still hard work, they would get some grain in there boots but that's about all. These days I doubt if they're allowed out of their vehicles.

Just read this post, and noted the interesting points highlighted. Over the years I have carted thousands of tons of Canola, using only the grain locks pictured. Certainly it is imperative that no part of the tail-gate assembly is damaged, or distorted, as things could get a bit messy if such was the case!

However, we never walk on the load, although balancing on the headboard or tailgate to sort out "stuck" tarps is a regular occurence!

Regarding " doubt if they're allowed out of their vehicles" on the contrary we must get out at the delivery point, for two reasons.

1) At the sample shed we must wind back tarps to allow samples of grain to be taken from each trailer for testing, and

2) At unloading point we have to again get out of the cab to release the grain locks, as the staff on duty at delivery point are expressly forbidden from touching anything except the actual air-release button on the tail-gate. This is claimed to be for their "safety". Cheers

-- Edited b

-- Edited by yobarr on Monday 24th of April 2023 12:00:18 PM

dogbox · Guru

Craig1 wrote:

I remember in the "old days" before aluminium tippers were the norm most gain was delivered on flat bed trucks with grain chutes ever 2 metres."

Also you needed " grain curtains ", which from my memory were mongrel plastic strips sewn to canvas sides. The strips laid on the boards and the weight of the grain held them down. BUT, Loading - you had to be there shoveling grain onto said placky bits at the start, so that was a 96 foot round trip pushing/shoveling grain, so everything all sat square and tight.

i have carted grain on flatbed trucks, hang curtains upside down inside gates then filler up. usually, a few mice came out when auger starts up. unloading was easy drove truck on to hydraulic ramp pulled rear gate out, whole truck lifted by ramp, (instant tipper) grain poured out back very little shoveling, if no ramp grain gates in floor a bit more shoveling with that method. we use to do it as aback load the tippers made the job so much easier.

yobarr · Guru

dogbox wrote:
Craig1 wrote:

I remember in the "old days" before aluminium tippers were the norm most gain was delivered on flat bed trucks with grain chutes ever 2 metres."

Also you needed " grain curtains ", which from my memory were mongrel plastic strips sewn to canvas sides. The strips laid on the boards and the weight of the grain held them down. BUT, Loading - you had to be there shoveling grain onto said placky bits at the start, so that was a 96 foot round trip pushing/shoveling grain, so everything all sat square and tight.

i have carted grain on flatbed trucks, hang curtains upside down inside gates then filler up. usually, a few mice came out when auger starts up. unloading was easy drove truck on to hydraulic ramp pulled rear gate out, whole truck lifted by ramp, ( instant tipper) grain poured out back very little shoveling, if no ramp grain gates in floor a bit more shoveling with that method. we use to do it as aback load the tippers made the job so much easier.

Although American, this is an example of using a hydraulic ramp to tip.