Perforated twinwall for grain aeration

[Clive]

Just done a few calcs while moleploughing.

I can have almost exactly double the number of cooling points and not lose any extra space.

Assuming 3 m high each

Pedestals 1m x 450mm? Then 2m x 110mm?

Each pedestal is 0.235067 cubic m

Each 110mm one is 0.11404 cubic m

So two use 0.22808 cubic m


Or 2.06 small bore compared to each pedestal.

I will keep an eye on cooling.
I'm fairly confident though as I've kept 200 tonne cool with screw in spears before now.

What's the recommended spacing for pedestals?

correct spacing for a pedestal is dependant upon storage depth - ie radius ventilated will be = to the depth of crop


so the deeper you go the further apart you can put them

 

[Badshot]

correct spacing for a pedestal is dependant upon storage depth - ie radius ventilated will be = to the depth of crop


so the deeper you go the further apart you can put them

Assume 3m deep, I seem to recall the same square is cooled? So 3 m apart?

I need to get some temperature differential controllers now really. Then see how effective they are.

 

[Clive]

Assume 3m deep, I seem to recall the same square is cooled? So 3 m apart?

I need to get some temperature differential controllers now really. Then see how effective they are.

I can do you one of these ?

For single phase - Monitors crop temperature and ambient air temperature. Will run 2 x 1.1kw fans only when air temperature is low enough to effectively cool the crop. Avoids unnecessary fan running times. Complete with 2m crop temperature spear and ambient air temperature probe. Inbuilt fan running time clock. This unit arrives ready to use and requires no installation. £395

or the 3 phase version

This unit will monitor crop and ambient air temperature in exactly the same way as the 1ph version. A signal will be sent from the Crop Cool box to the starters on the fans instructing them when to run. This unit will require an electrician to install. It can run multiple fans. A multi Fan Hub should be considered if you are planning to control multiple fans. £355

A humidity sensor can be added to the above for £150

used in combination with a Multi fan hub for either 2, 4 or 6 x 1.1 or 2,2kw pedestal fans

Enclosure with 32 amp supply socket ready to plug directly into farmer's 3ph supply. Facility to plug in up to 6 fans via 16amp panel mounted sockets. Hub will switch fans on when RUN signal is received from Crop Cool controller. Hub contains all necessary protection for motors, contactors and conductors. Additional timer fitted so that fans are switched on in 3 stages. Hub contains all necessary protection for motors, contactors and conductors

2 fan version £960
4 fan version £1140
6 fan version £1220



all of the above will reduce wasted fan run time and time taken to get crops cool

 

[Badshot]

I can do you one of these ?

For single phase - Monitors crop temperature and ambient air temperature. Will run 2 x 1.1kw fans only when air temperature is low enough to effectively cool the crop. Avoids unnecessary fan running times. Complete with 2m crop temperature spear and ambient air temperature probe. Inbuilt fan running time clock. This unit arrives ready to use and requires no installation. £395

or the 3 phase version

This unit will monitor crop and ambient air temperature in exactly the same way as the 1ph version. A signal will be sent from the Crop Cool box to the starters on the fans instructing them when to run. This unit will require an electrician to install. It can run multiple fans. A multi Fan Hub should be considered if you are planning to control multiple fans. £355

used in combination with a Multi fan hub for either 2, 4 or 6 x 1.1 or 2,2kw pedestal fans

Enclosure with 32 amp supply socket ready to plug directly into farmer's 3ph supply. Facility to plug in up to 6 fans via 16amp panel mounted sockets. Hub will switch fans on when RUN signal is received from Crop Cool controller. Hub contains all necessary protection for motors, contactors and conductors. Additional timer fitted so that fans are switched on in 3 stages. Hub contains all necessary protection for motors, contactors and conductors

2 fan version £960
4 fan version £1140
6 fan version £1220

all of the above will reduce wasted fan run time and time taken to get crops cool

That single phase one looks useful.
My fans are only. 0. 25kW, so it would run 8?

 

[Clive]

That single phase one looks useful.
My fans are only. 0. 25kW, so it would run 8?

it only has x2 outputs but I guess you could split them IF an electrician advices you it's safe to do so (im no electrician so cant advise you on that !) the outputs become live when the temp diff parameter you set is satisfied

IMO it would probably be worth adding the humidity senor as well so you don't run fans when air is damp and wet the crop

 

[Badshot]

Just done a few calcs while moleploughing.

I can have almost exactly double the number of cooling points and not lose any extra space.

Assuming 3 m high each

Pedestals 1m x 450mm? Then 2m x 110mm?

Each pedestal is 0.235067 cubic m

Each 110mm one is 0.11404 cubic m

So two use 0.22808 cubic m


Or 2.06 small bore compared to each pedestal.

I will keep an eye on cooling.
I'm fairly confident though as I've kept 200 tonne cool with screw in spears before now.

What's the recommended spacing for pedestals?

Feck got the sums wrong


Each small bore tube is only 0.02851 cubic m, so there could be over 8 in the same space as one pedestal.

I used the diameter instead of the radius, sorry folks.

 

[Badshot]

Now, they've been on for 24 hrs.

In a straight line across the shed the side with no fan is at 23.6c. That's about 10 feet from a fan.
Move to halfway. 5 feet, the temp is 21.3.
Right next to the fan is 20.6.
I reckon ten foot spacing will be fine.
Temp taken at full depth of the spear. 4-5 foot.
I'm happy enough with that.

 

[Badshot]

I have a bit more to add today.
I got some more perforated twinwall. Some unperforated twinwall to use for the top section.
The unperforated is too flexible
So, I have now moved to 1 m perforated at the bottom. 1 m unperforated. Tgen 0.75 m downpipe for the top. Its rigid and stops the fan falling over.
Still seem to have plenty of airflow, it cooled 4 feet from the fan 4 degrees overnight.

One thing I have learned is to have a solid pipe on the hoover so the flexible one doesn't get under the twinwall
It also keeps the twinwall more upright too.

 

[KennyO]

@Bagshot I'm sure I saw in Pfi someone using full lengths of solid downpipe for this method and either drilling it or slitting it with a very thin grinder disc for ventilation.

 

[KennyO]

@Badshot even

 

[Badshot]

@Bagshot I'm sure I saw in Pfi someone using full lengths of solid downpipe for this method and either drilling it or slitting it with a very thin grinder disc for ventilation.

That would work too.

I've got the shed set up on 10 foot spacing now, see how it goes.

 

[mikep]

Feck got the sums wrong


Each small bore tube is only 0.02851 cubic m, so there could be over 8 in the same space as one pedestal.

I used the diameter instead of the radius, sorry folks.

Won't be a straight comparison as airflow capacity is only one factor depends also on fan and depth as well as smaller factors such as moisture and cleanliness. More Smaller units have less work to do as it is easier to move air closer to the pedestals rather than try to suck air from a larger radius as with one larger.
Looks much easier than winding in those spot coolers.

 

[Badshot]

Won't be a straight comparison as airflow capacity is only one factor depends also on fan and depth as well as smaller factors such as moisture and cleanliness. More Smaller units have less work to do as it is easier to move air closer to the pedestals rather than try to suck air from a larger radius as with one larger.
Looks much easier than winding in those spot coolers.

I realise it's not simple. The larger pedestal tube is required to get enough slots to allow airflow through. How many slots woukd be required to match the open Base of these. Plus the slots of course.

It does appear to be working quite well so far.

And yes it's a lot better than screwing spears in, and it goes to the floor, unlike the spears at 6 foot long.

 

[mikep]

The other advantage of the multi minis would be better coverage at floor level. Non of them can suck air horizontally but downwards in a fan shape which leaves a triangular area in the middle of two pedestals uncooled. The more pedestals ie closer together no matter what capacity will cover more of the deeper gain which is really what you want. I think you have a win win situation with them.

 

[Badshot]

OK. At 6 feet from the fan it's dropped the temp 6 degrees since last night.

 

[JCfarmer]

Assume 3m deep, I seem to recall the same square is cooled? So 3 m apart?

I need to get some temperature differential controllers now really. Then see how effective they are.

Liking that Badshot over the spears, 3m deep will cool 3m radius so spacing 6m apart.

 

[Badshot]

Quick update.
This works very well, I've got my heap down around 5c with the recent frosts.
Very pleased.
1 m of perforated at the bottom works fine and forces the air to go right to the bottom.

 

[JD6920s]

Quick update.
This works very well, I've got my heap down around 5c with the recent frosts.
Very pleased.
1 m of perforated at the bottom works fine and forces the air to go right to the bottom.

Have you ever tried putting a Lishman pedestal in with the hoover?
I guess it would work just the same.
It's a great idea btw.

 

[Surgery]

If you want to use cheap twinwall I would do it this way


you could use a pitot gauge to measure flow but the real test will be how well and even you are able to cool crops

If I was going to use twinwall I would lie it on the floor as laterals - that way you would get even airflow through the heap top to bottom

Good idea but as you mentioned loss of space due to having the pipe upright , in an earlier post. ,would lying the pipe on the floor require an air tunnel ?

 

[Clive]

Good idea but as you mentioned loss of space due to having the pipe upright , in an earlier post. ,would lying the pipe on the floor require an air tunnel ?

as in my earlier posts there are significant differences between the polycool pipes and twinwall drain pipe - I would really worry about getting enough flow through the crop

only real reason for a tunnel is so you can use x1 big fan vs several smaller ones really


As this thread has come back to top I have some exciting new fan control products coming soon , they can be retrofitted to existing fans (pedestal or fixed), have there own crop and ambient probe and LCD screen to display current setting and change between a number of cooling, drying or conditioning programmes.

Really neat big of kit IMO at a LOT less cost than the full on wifi store control systems my www.monitorandmanage.com company sells - anyone looking at this kind of thing dont buy anything until you have seen this ! will launch pretty soon !