[Stoves] FW: pot skirt efficiency estimates, scale-up

[Kevin C]

Dear Joshua

It is good to see your project "coming together!"

I have deleted stuff that does not include a specifgic comment from  
me... see below...

Quoting Joshua Guinto <jed.building.bridges at gmail.com>:

> Dear Crispin and Kevin
>
...del...

> To respond to some of Kevins question.
>
> they are in between the lines...
>
> 2012/9/19 Kevin C <kchisholm at ca.inter.net>
>
>>
>> Dear Jed
>>
> ...del...

>> I might be able to help with operation of the distilling aspects of your
>> project.
>>
>> 1: Is it a continuous process or a batch process?
> It is a batch process, one load is about 115 liters .
>
>

>> 3: What percentage of ethanol do you want in your final distillate product?
>>
> Hmmm right now, the latest test indicates 70 percent with the traditional
> methods We want to increase that to as much as 90 %.

# With a reflux column, you can get between 90% to 95% without  
difficulty. A big advantage of trying for 95% is that it basically  
eliminates contaminants, such as fusel oils, butanol, propanol, and  
methanol.
>
> 4: Do you use a simple condenser, where you simply condense all the vapor
>> that is boiled off, or do you use a reflux column?
>>
> We use a simple condenser. Actually, i have a clay condenser fabricated.
> But i neglected to have the inside walls glazed. So i will only use that
> until it is glazed. For the meantime we will use the metal condensers that
> the locals fabricate themselves.

# A simple condenser does not give nearly as good a separation as does  
a reflux column. I would suggest that you are far better off going to  
a reflux column, to virtually eliminate the undesirable impurities in  
the distillate, and to yield a much more concentrated and pure ethanol.
>
>
>> 5: What is the initial alcohol content of the "feed wine?"
>>
>
> That i wll check tommorow.

# I would guess that it is about 12%. A ferment with sufficient sugar  
to yield only 12% alcohol ferments out quickly, while one that has  
sufficient sugar to eventually permit say 15% is much more difficult  
to ferment to completion, and takes disproportionately longer. You can  
ferment to these higher alcohol contents, but you have to add  
appropriate yeast nutrients. Unless you have access to a  
Microbiologist, you are probably better off targeting for 12% alcohol  
maximum. You should also have a hydrometer, to measure the specific  
gravity of the ferment.
>
> 6: How many litres per hour of "feed wine" do you wish to process?
>>
> Sixteen liters in one hour will already be satisfying.
>
# This will basically depend on your firing rate. Assuming that your  
boiler has about 4 square meters of area, your heat input rate to the  
batch could be as much as about 40 kw. Very roughly, this would need  
about 60 kW of input energy, allowing for combustion losses and stack  
temperature loss. This would require a fuel burn rate of about 12 kg  
dry fuel equivalent per hour. You should fire it at " as much as  
possible", consistent with complete combustion (no smoke in the stack)  
and a maximum stack temperature of about 200 C. NOTE: These  
calculations are rough; they are generally proportional to area for a  
steel drum, but the pottery walls will have higher heat flow  
resistance, and consequently, with the same outside temperature, would  
have lower heat input rates to the batch. For your first "test run",  
you could start off with a "batch of water", and measure its rate of  
temperature rise, to determine the actual heat input rate to teh batch.
>>
>> I don't understand your separating technology. What is condensed or cooled
>> in the "Radiator?"
>>
> The radiator was meant to cool off he cooling water that runs on top of the
> condenser so we may use them again in a continuing cycle.
>
# Good move!! You don't have to haul in, or pipe in, as much cooling water.
>
>> What is the source and  nature of the "waste water" that is being sent to
>> the "Waste Water Treatment tanks?"
>>
> This would be the distillate, the spent liquid after the distillation. I
> would not want them disposed directly to the creeks.

# You could probably re-use the "spent batch" several times as make-up  
for the next batch. This would reduce your treatment cost and effort.
>
>
>>
>> You would probably benefit from Thermometers at various points in the
>> still and condensers. You should also have valves in the water cooling
>> pipes, to regulate the flow rate of water from your head tank.
>>
>
> Yes, i agree. I think i will do a monitoring chart for every point ...
>
# I would suggest:
1: Stack temperature... 0 to 250 C
2: "Final vapor temperature to the "final condenser." 0-100 C
3: Water temperature around reflux condenser jacket. 0-100 C
4: Temperature of vapor entering the reflux condenser. 0-100 C

# get thermometers with at least a 4" diameter dial for ease of  
reading. Calibrate them in a hot water bath, so that you have  
confidence in what each thermometer really indicates.
>>
>> Am I correct in assuming that your "Radiator Assembly" cools your
>> condenser or reflux column water flow, to permit re-use? If so, you could
>> use a radiator or two (depending on how much heat you have to dissipate)
>> from scrapped automobiles for cooling the condenser water for re-use.
>>
>
> Good idea. For now im using a simple fine net like those of the mosquito
> nets. I do not know if it will not melt off
>
# Is this basically an evaporative cooler?  If so, it may not work  
very well if your ambient temperatures and relative humidities are high.
>>
>> Your pottery boiler looks great! I presume you are using it, to minimize
>> differences in operation from the technology presently being employed.
>>
>>
> The present technology is actually the use of metal drums they get from the
> industries..... They could contains remains of chemicals, diesel, oil,
> shampoo or anything. they clean the drums very crudely. The drums lasts
> only for several months because of metal fatique. Then they wlll have to be
> replaced.
>
> The clay boiler is actually going back from the modern to the more native.
>
# 30 or 45 gallon drums with a clamping lid are easy to clean.  
However, you do need a good gasket, to avoid loss of alcohol vapor and  
a possible fire or explosion. Bung type drums are very cheap, and with  
careful washing, they should be acceptable. I am guessing that if the  
bottom fails, it is not so much from fatigue, but rather, from  
overheating as a result of organic deposits resulting from feed that  
was not adequately settled before feeding to the boiler. Periodic  
cleaning of the inside of such a boiler should extend its life.
>
Best wishes,

kevin

>> Best wishes,
>>
>> Kevin Chisholm
>>
>>
>> Thank you both once again. More news  to come
>>
>
> Jed
>
>> Quoting jed.building.bridges at gmail.com**:
>>
>>  Dear All
>>>
>>> With all respects, i wish to join in the discussion with my own concern
>>> similar to that of Josh Kearns.
>>>
>>> Im at present building an improved wine distillery in favor of the small
>>> nipa wine producers in my hometown. The constructin is now in full scale
>>> and
>>> so im beginning to really get worried about the integrity of my design.
>>>
>>> I do not have enough engineering background on this and do not have much
>>> equipments. So i would really appreciate it if you could also guide me
>>> through with this project.
>>>
>>> I attached some photos and drawings of the project.
>>>
>>> It was organized by a Japanese  JICA volunteer and will help more than 200
>>> wine producers not to mention their health and the immediate environment.
>>>
>>> Best regards
>>>
>>> JEd Guinto
>>>
>>> 2012/9/16 Paul Anderson <psanders at ilstu.edu>
>>>
>>> Josh,
>>>
>>> From experience, having the heat go through a single pipe/chimney in the
>>> center of the water tank is much better than having  the heat go around
>>> the
>>> outside of the steel drum.    And it is much less expansive.
>>>
>>>
>>>
>>>
>>>
>>> Paul S. Anderson, PhD  aka "Dr TLUD"
>>> Email:  psanders at ilstu.edu   Skype: paultlud  Phone: +1-309-452-7072
>>> Website:  www.drtlud.com
>>>
>>> On 9/14/2012 11:36 PM, Josh Kearns wrote:
>>>
>>> I'm thinking about building a 5-gal TLUD fired 55-gal water heater for
>>> outdoor showers. I'm wondering if anyone has a ballpark estimate for heat
>>> transfer efficiency w/ and w/o using a pot skirt attachment. The hot water
>>> tank will be a 55-gal steel drum, so I think the setup is pretty analogous
>>> to a cookstove setup, just bigger.
>>>
>>>
>>>
>>> 20%?
>>>
>>>
>>>
>>> Any thoughts are helpful, rough estimates OK.....thanks!
>>>
>>>
>>>
>>>
>>>
>>> FYI, the char from the water heating setup will be used in arbor-loo style
>>> modular composting toilets. This infrastructure is being installed during
>>> a
>>> rambo design-and-build sesh for my wedding on a farm in rural Appalachia
>>> (USA), but will be used continually by future events at the site. Cool,
>>> huh?!?!
>>>
>>>
>>>
>>> Josh
>>>
>