[Gasification] questions for Tom Reed on stratified downdraft parameters

[Ken Calvert]

Jeff n all, Hi!
                    I think that you have got your thermodynamics all wrong. 
The major heat load of hot gas is in the
latent heat of vapourisation of the moisture.    It takes a lot of heat to 
boil water into steam and when steam condenses
back into water it gives back that heat. All that happens at 100oC. Will an 
Icyball  run at 100oC?
To cool gas at  say 500oC down to 200oC doesn't take much effort, and that 
means that it won't give up much energy either.
Too old and too lazy to do the maths on that but check it out.  Don't take 
it that I am a downer on your ideas. Keep thinking, but
this is supposed to save you a lot of effort in experimentation.  Cheers Ken 
C.


----- Original Message ----- 
From: "Jeff Davis" <jeff0124 at velocity.net>
To: <gasification at listserv.repp.org>
Sent: Wednesday, April 18, 2007 9:27 AM
Subject: Re: [Gasification] questions for Tom Reed on stratified downdraft 
parameters


> Dear Tom,
>
> It's the heat that the IcyBall would absorb, in order to recharge it's
> self. Like a heat absorbtion fridge. We can use the waste heat in the gas
> outlet to power an absorbtion fridge system. Next the system can cool the
> gas.
>
>
>
> Jeff
>
>
>
>> Dear Jeff:
>>
>> Not my field of expertise, but I doubt if any of the gases in producer
>> gas would be absorbed in the icy ball cycle...  Just intuition.
>>
>> TOM REED
>> ------------------------------------------------------------------------
>>
>> Jeff Davis wrote:
>>> Dear Tom & All,
>>>
>>>
>>>
>>> I?ve considered using an automotive A/C unit to cool the gases just
>>> before
>>> the engine. I would think that this would remove a sizeable amount of
>>> the
>>> moisture from the gas.
>>>
>>> Now with the discovery of the IcyBall waste heat from the gasifier, and
>>> or
>>> engine, could possibly be employed to cool the gas. In a simple batch
>>> mode
>>> you would have two IcyBalls, one being recharged via the waste heat and
>>> the second cooling the gas. Of course they would require manual
>>> exchange.
>>> Possible a re-circulating absorption cooler could be designed for this
>>> task?
>>>
>>>
>>> Jeff
>>>
>>>
>>>
>>>
>>>
>>> Tom wrote:
>>>
>>>> The efficiency and power of engines depends in part on the temperature
>>>> of the intake mixture, and since we have gases, it would be tempting to
>>>> have the lowest possible input temperature to the engine.  However, as
>>>> you point out, paper filters and baghouses rapidly collect the fog and
>>>> can generate too high a pressure drop.
>>>> The easiest solution is to control your input air to 60 or 70C,
>>>> depending on input fuel moisture and accept the small loss in power
>>>> (make up with turbo charger?).
>>>>
>>>> Another solution could be to cool the gas to 10C (if you have a cold
>>>> river nearby), drop out the fog, then reheat to 15 C to keep the
>>>> filters
>>>> dry.
>>>>
>>>> Good subject for discussion...
>>>>
>>>> TOM REED               BEF
>>>> ------------------------------------------------------------------------
>>>>
>>>> Jeff Davis wrote:
>>>>
>>>>> Jim wrote:
>>>>>
>>>>>
>>>>>> 6. filters:
>>>>>> i am finding dry filters for secondary particulate filtering to not
>>>>>> stay
>>>>>> very dry, and generally become rather useless very quickly.  or
>>>>>> rather,
>>>>>> they get wet and then require huge vacuum to pull through them.  i am
>>>>>> using
>>>>>> shop vac paper/synthetic filters.  i am using them after a giant
>>>>>> cooler/radiator and the gas going into the filter is very cool.  i
>>>>>> think
>>>>>> about 80-90deg.  i realize i could reheat partially before the filter
>>>>>> to
>>>>>> prevent this problem, but such isn't very attractive.  so from the
>>>>>> experience of others out there, are dry "paper" filters generally
>>>>>> unreasonable on gasifiers for condensate reasons?  do dry filters
>>>>>> usually
>>>>>> end up as some sort of sawdust, coffee or other granular filter
>>>>>> media?
>>>>>> are
>>>>>> others finding the "wisdom" of wet filters after the failure of dry
>>>>>> ones?
>>>>>>
>>>>>>
>>>>> Dear Jim,
>>>>>
>>>>>
>>>>> Yes, dew point is a big issue with dry filters.
>>>>>
>>>>> You might want to give composted horse dung a try.
>>>>>
>>>>> Better yet, moss. It keeps it's spongyness well.
>>>>>
>>>>>
>>>>>
>>>>> Jeff
>>>>>
>>>
>>>
>>>
>>>
>>
>
>
> -- 
> Jeff Davis
>
> Some where 20 miles south of Lake Erie, USA
>
> _______________________________________________
> Gasification mailing list
> Gasification at listserv.repp.org
> http://listserv.repp.org/mailman/listinfo/gasification_listserv.repp.org
> http://gasifiers.bioenergylists.org
>