Woodchip drying bins

[T Hectares]

I'm currently drying around 5000m3 of chip a year through 2 x 28m3 Hooklift bins with drying floors attached to a L-enz unit.
The bins really struggle to achieve a consistent chip moisture content as they tend to over dry the bottoms of the bins and the moisture recondenses in the top couple of feet, any tips to improve this or would a horizontal air flow bin be a better bet??

 

[A1an]

This happens with most systems that dry from below and don’t have stirrers. The top chips will be likely wetter than when you put them on.

If consistent mc is an issue the stirrers would be an option.

 

[T Hectares]

This happens with most systems that dry from below and don’t have stirrers. The top chips will be likely wetter than when you put them on.

If consistent mc is an issue the stirrers would be an option.

 

[T Hectares]

Stirrers not really an option for Hookift bins are they ??

 

[scotston]

Dry with constant humidity. Eventually the whole lot becomes the same moisture content. Google equilibrium moisture content.

 

[T Hectares]

The issue with this is that it would take longer than using heat, and we need the output!!

 

[scotston]

Errmm. You use heat to get constant humidity? Or perhaps I'm muddled.

 

[T Hectares]

No you’re not muddled...

I meant that my heat exchanger controller uses a heat based regulation system with no provision for humidity control, and that when drying grain humidity correction control will take longer to dry the grain, although more economically than compared to keeping a constant heat.

 

[wilber]

These look good http://www.woodtekenergy.co.uk/wood-chip-dryers

not that you want to change your current setup though.

 

[T Hectares]

These look good http://www.woodtekenergy.co.uk/wood-chip-dryers

not that you want to change your current setup though.

Yes, they do look good.

Was wondering if these HAF bins are more efficient than my current VAF ones??

Hook trailer container shuttling
Stronga design two types of drying containers which work alongside Heatex and the HookLoada trailer for the transport, delivery and storage of wet materials like woodchip, digestate, waste and much more:

1. Horizontal airflow (HAF containers)
2. Vertical airflow (VAF containers)

 

[scotston]

i dry my chip with constant humidity of 35% to 10mc for my chp. Doing around 50t/month. uses about 50kw of heat. chip 8-10% all the way through.

 

[T Hectares]

i dry my chip with constant humidity of 35% to 10mc for my chp. Doing around 50t/month. uses about 50kw of heat. chip 8-10% all the way through.

Is this on a drying floor??

 

[scotston]

two x one hundred ton (wheat) floors. i dry one floor at a time so one has dry chip while the other is drying. In summer I stockpile the chip so I can dry grain.

 

[Doing it for the kids]

i dry my chip with constant humidity of 35% to 10mc for my chp. Doing around 50t/month. uses about 50kw of heat. chip 8-10% all the way through.

two x one hundred ton (wheat) floors. i dry one floor at a time so one has dry chip while the other is drying. In summer I stockpile the chip so I can dry grain.

Have you any pics? How do you use so little heat?! How deep is the pile? What fan size/ power consumption

 

[Doing it for the kids]

I'm currently drying around 5000m3 of chip a year through 2 x 28m3 Hooklift bins with drying floors attached to a L-enz unit.
The bins really struggle to achieve a consistent chip moisture content as they tend to over dry the bottoms of the bins and the moisture recondenses in the top couple of feet, any tips to improve this or would a horizontal air flow bin be a better bet??

Have you any pics? I am drying similar amounts using drying floors but can't seem to get my efficiencies to where I want them to be. What size fans are you using, how much heat and power do they need per batch?

I've tried spreading it thinner over a larger surface area, hoping the reduction in air flow is off set by the reduction in height so less wet capping

 

[scotston]

I have two 15kw fans and the floor is on 5" bearers to give huge airflows when needed for wheat. But most of the time I use one fan on one side with the chip around 4ft deep. I can dry at 6ft but 4ft is plenty for 2wks running. probably takes a week to dry but hard to say as the drier comes on automatically by the chp when the buffer is too hot. The rest of the time the heat goes into the chook shed. Constant humidity means you can walk away and leave it and although you get very wet chip at the top, that too dries if you're patient. If I have very wet grain, say 25% mc then I use a grain butler to stir it a little to stop it going rock hard. Once it's done below 20%mc it sorts itself. 40%rh gives me chip at 10%, 65% rh gives me grain at 14.5%mc. Stirring reduces drying time to a third compared to no stirring. If it is raining outside then the ambient is 100%rh, you need a lot more heat than on a nice summer day when the rh is 60%. Using temperature dependent drying instead of humidity means that your chip moisture will fluctuate depending on the ambient rh, which in turn fluctuates throughout the day.

 

[Fowler VF]

Was wondering if these HAF bins are more efficient than my current VAF ones??

Certainly better with the horizontal flow, but you will still get some uneven drying. Constant humidity control will solve this, but it will still take longer to get the bin dry. You cant avoid the fact that the moisture will re-condense on the colder layer of chip. Horizontal flow allows a smaller distance for the air to travel, so the temperature gradient is less, same as a shallower layer of chip on a floor. Constant humidity control means that you don't overdry the bit nearest the air by the time the bit farthest away is dry. The black art of bulk drying!! Belt or cascade drying is the ultimate for throughput and best use of available heat, but also needs control of both temperature and humidity to achieve best results.