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Thread: Biomass boiler to dry grain

  1. #1
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    Biomass boiler to dry grain

    I am in the process of installing a woodchip boiler to heat the house probably a 35-50kw unit.

    This led me to think that I could use it to dry grain (or even the woodchips themselves), it will only need to do 100-200 ton a year so nothing too elaborate required.

    I was thinking of converting a shipping container so I could tow it to the house, and couple up the boiler to a heat exchanger with a fan to blow hot air through ducting to dry each batch of say 20 ton.

    Anybody had any experience in this, sizes of fans and exchangers and hopefully someone knows of a couple of secondhand units lieing about that could be bought.

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    Re: Biomass boiler to dry grain

    Someone had a dragon boiler, and used heat through 8x4 rads to blow heat through grain, maybe on old bff site?

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    Re: Biomass boiler to dry grain

    Are we speaking about house rads lined up away from the fan?

    Blowing through old lorry rads wouldn,t be particularly efficient would it, anyone tried that on here?

    Just thought heat exchanger is designed for maximum heat loss so would be more cost effective long term, as most of the energy (cost) would be in this as long as the transfer (drying) process is efficient.

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    Re: Biomass boiler to dry grain

    I have been looking at this, and you need a big surface area of exchanger to get enough air flow and enough heat transfer. Been doing calcs for a 120kw system, but I think you may struggle to get enough heat from a 35kw to warrant the work involved. The problem with adding warm air to grain drying is increased moisture carrying capacity, so you need to add enough heat quickly enough to prevent the grain sweating and 'capping' preventing air then ventilating the crop. How are you planning to force the air through the grain? Any idea of air volume you'll be forcing through?

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    Re: Biomass boiler to dry grain

    I have sent you a pm

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    Re: Biomass boiler to dry grain

    We used a Dragon to dry grain on a floor store. No hope of getting enough heat for continuous flow drying. We calculated that we needed at least 250kW to be useful, and 350kW to replace the two Harvest CHC burners. We had a special radiator made, 2 row about 2m x 1m, but if I was doing it again with biomass would probably use a heap of old lorry radiators. The fans sucked through the radiator. We are still using the fans/radiator system, but without the boiler as we have plenty of heat from the biogas CHP.

    The best way to go about it is to determine the maximum amount of air you require, then how much heat you need to reduce the humidity to a level at which useful drying occurs. I could post photos if of interest

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    Re: Biomass boiler to dry grain

    Yes please to the photo's! Great info as well, I'm thinking of making own radiator but perhaps lorry rads better value.

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    Re: Biomass boiler to dry grain

    Yes please, our Dragon is next to a grain store

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    Re: Biomass boiler to dry grain

    [IMG] [/IMG]

    Photos of the radiator in the fan house, let into the wall. You can just see the end of the Harvest CHC burner in bottom right. The Dragon boiler supplies the rad through 3" pipes. I found that 6" guttering cable ties nicely over the lagging on 3" pipes, to protect it from weather, birds etc. The control panel I developed to get decent temperatures without pushing too much heat up the flue. I have since supplied several for Dragons, and at least one to a grain drying installation.

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    Re: Biomass boiler to dry grain

    Quote Originally Posted by sjt01 View Post
    [IMG] [/IMG]

    Photos of the radiator in the fan house, let into the wall. You can just see the end of the Harvest CHC burner in bottom right. The Dragon boiler supplies the rad through 3" pipes. I found that 6" guttering cable ties nicely over the lagging on 3" pipes, to protect it from weather, birds etc. The control panel I developed to get decent temperatures without pushing too much heat up the flue. I have since supplied several for Dragons, and at least one to a grain drying installation.
    Can I ask why the radiator is on the side and not on the fan inlet like a engine radiator?

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    Re: Biomass boiler to dry grain

    what size dragon is that, don't look too big ?

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    Re: Biomass boiler to dry grain

    The fan is on the only route for air into the fan house. There are two fans, with either one or two working.

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    Re: Biomass boiler to dry grain

    The Dragon was a double pass, which could take a 5' round bale. Since been replaced by biogas chp, for which the radiator acts as heat dump

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