Search found 302 matches

by Bob
Sat Nov 15, 2008 11:30 am
Forum: General Catchall
Topic: wood stove TEG
Replies: 2
Views: 11987

Re: wood stove TEG

Hi Carola,

Sorry for the delay in responding. I've been traveling, just returned.

Check out http://www.hi-z.com/ for TEG modules.
by Bob
Tue Nov 04, 2008 7:06 am
Forum: General Catchall
Topic: Infrastructure On A Skid
Replies: 1
Views: 10418

Re: Infrastructure On A Skid

Hi Tia,

Thanks for the kind words. I'm currently in Costa Rica, checking in at an internet cafe. Will respond in more detail when I return to Alaska next week.
by Bob
Mon Oct 20, 2008 10:42 am
Forum: Anaerobic Digester
Topic: Complete, Portable Units Available in US?
Replies: 4
Views: 14687

Re: Complete, Portable Units Available in US?

The more I think about making this viable, the more I think that a single large system would probably be more cost-effective than a distributed system. I agree. You can't get enough gas from a small (e.g. single family) system to justify the added expense of automation, gas scrubbing and/or compres...
by Bob
Fri Oct 17, 2008 10:39 am
Forum: Anaerobic Digester
Topic: Complete, Portable Units Available in US?
Replies: 4
Views: 14687

Re: Complete, Portable Units Available in US?

Hi, Mike, I'll be interested to hear what you learn about the Sintex unit. It looks interesting. From my own experience, the digester itself ($425) is a small part of the total installed cost of a complete operating system. The total cost will depend to some extent, on how much daily maintenance peo...
by Bob
Sat Oct 11, 2008 12:00 pm
Forum: Bioshelter
Topic: my modified earthship vs. your bioshelter :)
Replies: 4
Views: 32255

Re: my modified earthship vs. your bioshelter :)

About the only thing the two buildings have in common are the underlying design principles (e.g. integration of whole systems to capture multiple benefits, economic valuation of whole systems, rather than individual components, etc.). The new building, currently under construction, is a simple 28x24...
by Bob
Thu Oct 09, 2008 6:06 pm
Forum: Bioshelter
Topic: my modified earthship vs. your bioshelter :)
Replies: 4
Views: 32255

Re: my modified earthship vs. your bioshelter :)

Hi Steve, Apologies for not responding sooner. I just discovered your posts, now two weeks old. Here are some quick responses... I'd also be very interested in any specifics you could share as to your ideas on how such a home be best laid out. Not really, not without knowing more about the site spec...
by Bob
Tue Sep 16, 2008 11:20 am
Forum: Anaerobic Digester
Topic: Can I use straw as a raw material input?
Replies: 5
Views: 16240

Re: Can I use straw as a raw material input?

Wow. Has it been 8 years? Sorry to hear about unemployment, Nathan, but glad that it affords you opportunity to pick this up again. I skimmed the straw treatment article, and found the ammonia treatment (para 79) and the biological treatment (White rot fungi, para 84) sections most interesting. Will...
by Bob
Thu Sep 04, 2008 9:41 am
Forum: Anaerobic Digester
Topic: human waste degester
Replies: 1
Views: 10871

Re: human waste degester

Hi Lou,

Do you have a working budget? There are many possible designs, ranging from some that are very low cost, but which are also more difficult to operate and maintain, to others that will perform better, be more highly automated, and/or be easier to maintain and operate.
by Bob
Thu Sep 04, 2008 8:43 am
Forum: Composting Toilet
Topic: Orpah School excess water with flush toilets
Replies: 1
Views: 11101

Re: Orpah School excess water with flush toilets

Does any one have a working design that minimizes the amount of flushed water in a US design toilet. I used a Sealand toilet with a small holding tank (a 6" dia x 18" long" PVC pipe) mounted in the floor under the toilet, and pumped out to the composter with a hand pump. See details here . It used ...
by Bob
Mon Aug 18, 2008 9:49 am
Forum: Anaerobic Digester
Topic: a new AD forum guy
Replies: 11
Views: 33956

Re: a new AD forum guy

So you have to pump a lot more gas into it to get it to zero psig. (Sounds like you need to get going on your production scale digester... :) )

I guess the only way you could have a gage directly read absolute pressure would be if it were in orbit, not at the bottom of this ocean of air.
by Bob
Thu Aug 14, 2008 8:44 pm
Forum: Anaerobic Digester
Topic: BIOGAS COMPRESSING TECHNIQUES
Replies: 1
Views: 10842

Re: BIOGAS COMPRESSING TECHNIQUES

Hi Srinivas,

Don't know if you are still monitoring this, but check out this new topic. Billtu has some hands on experience with compressing biogas. In terms of practicality, I too am interested in determining feasibility, and if so, a way of optimizing it.
by Bob
Thu Aug 14, 2008 2:34 pm
Forum: Anaerobic Digester
Topic: a new AD forum guy
Replies: 11
Views: 33956

Re: a new AD forum guy

Another question: is Water Column figure from absolute psi? In other words 27.68"WC = 1psi or 1 psia?
It's psi.
by Bob
Thu Aug 14, 2008 12:55 pm
Forum: Anaerobic Digester
Topic: a new AD forum guy
Replies: 11
Views: 33956

Re: a new AD forum guy

After thinking about it further -- and asking around and getting some "how to think it" help from a friend, I think I have an answer for you on how to calculate the compression factor correctly. You need to use absolute pressure (psia) rather than gauge pressure (psig). Atmospheric pressure at seale...
by Bob
Wed Aug 13, 2008 9:49 am
Forum: Anaerobic Digester
Topic: a new AD forum guy
Replies: 11
Views: 33956

Re: a new AD forum guy

I hope somebody will correct me if i am wrong, but if i compress that to 100 psi, i will have 300 cubic feet of gas. So compressing as high as 250psi, i'd have 750 cubic feet. According to Boyle's Law , the relationship between pressure and volume is not linear, but in actual practice, I don't know...
by Bob
Tue Aug 12, 2008 3:19 pm
Forum: Anaerobic Digester
Topic: a new AD forum guy
Replies: 11
Views: 33956

Re: a new AD forum guy

Very interesting information, Billtu. Thanks. I don't have any sense of how much gas you can practically store in, say, a 100 lb propane bottle using an automotive compressor. Or about how much energy it would take to compress it. Have you worked any of these numbers out? (I'm also interested in bio...
by Bob
Wed Aug 06, 2008 9:01 am
Forum: Anaerobic Digester
Topic: a new AD forum guy
Replies: 11
Views: 33956

Re: a new AD forum guy

Hi Billtu,

Thanks for sharing! Great pix. I'd like to hear more about your experience with scrubbing and compressing the gas. I had no idea you could get those kinds of pressures from auto AC compressors.
by Bob
Mon Jul 21, 2008 2:09 pm
Forum: General Catchall
Topic: Storing the winter's "cold"
Replies: 3
Views: 14155

Re: Storing the winter's "cold"

I still haven't sat down and calculated the BTUs stored per module of ice for a cost-benefit analysis, since I will most likely have to create some pilot systems in order to determine the BTUs lost to ambient temperature differentials That is something that can be designed / engineered before actua...
by Bob
Mon Jul 14, 2008 9:12 am
Forum: Anaerobic Digester
Topic: mini digester...?
Replies: 32
Views: 93171

Re: mini digester...?

I fixed it, lyga. (The links got broken when I upgraded to a new version of the forum software.) Thanks for the heads up.

Jump to message.
by Bob
Tue Jul 01, 2008 5:54 pm
Forum: Anaerobic Digester
Topic: mini digester...?
Replies: 32
Views: 93171

Re: mini digester...?

I'm not sure which pictures you mean, lyga. Are you referring to images posted here in this topic?
by Bob
Fri Jun 13, 2008 1:51 pm
Forum: General Catchall
Topic: Storing the winter's "cold"
Replies: 3
Views: 14155

Re: Storing the winter's "cold"

Hi Nick, I don't have time for more than a quick "drive-by" response right now, but wanted to respond with something... ...if one were only interested in refrigeration and air conditioning, I wonder if storing up large amounts of ice in the winter could prove economical on a residential or even comm...