Sunday, April 12, 2020

PTEG Sucks! COVID-19 Post #9

Failed prints
 Things were going along fine until I ran out of PLA printing filament. I've given over 50 to the hospital and I've got 40 that are ready to take over tomorrow.

Then I got into the PETG filament. For this application this stuff is useless. The print temps are high, 240C, the bed temp needs to be 120C for these face shields. If the speed is more than 60 mm/s it doesn't seem like the filament melts fast enough in the hot end and it gets lumpy. And it's super stringy.

Managed to get some okay prints with the lower speeds.

The XYZ filament (translucent red) I got from B&H turned out to be total garbage. Once I got something out of it the print was brittle. The ear pieces broke on several prints.

The Overture filament (opaque white) came out a lot better. Way less stringy. It's also less brittle.

XYZ filament, super stringy
I'll keep working on it. I've got more PLA on the way. Should be here Tuesday. These face shields are needed now. The RTs & Nurses only have the ones I've sent over and some from another 3D printer who's donating them to nursing. Sounds like they are still short enough so everyone has one. They should have enough so they can throw them out if they get anything on them. That's going to be hard to do unless normal supply levels kick back in. So if I can print faster with PLA then that's the way to go.

Edit 4/13/20: Materials are almost all here. Amazon shipped the PLA early. It got here today. Jerry's Art-O-Rama shipped the last of the .007 Duralar & it arrived today. Over the weekend I got more .010 film from C.S. Hyde & Co. I have enough material for about 400 more units. Maybe more. There's another 300 units worth of film on the way in a couple weeks.

We'll see. The numbers are looking good in terms of the peak utilization. Still after six to eight weeks of supply issues they still don't have face shields or enough N95s to return to anything even close to normal. As a nurse on '60 Minutes' said, they are wearing medical waste every day. It's not as bad in CA as it is in NYC but it's not normal and it's not good.

I worry about my wife and her friends at work every day.

Overture filament, okay results
I've adjusted the proximity sensors, re-leveled the beds, purged the PETG, and am printing again. I think the proximity sensors were pretty significantly out of whack. That could have been part of the issue with the PETG. Still, the PLA printed fine even with the issues. So ... I'm saying PLA is the far more forgiving material.

As of today 97 have been delivered. I have another 100 to go before there will be enough for one round for respiratory & Nursing. Nursing is getting some from someone else too. So with both supplies maybe they'll have enough to be able to actually throw some out when they get more seriously contaminated.

Monday, April 6, 2020

NIH Stratasys Face Shield - COVID entry #8

Happy respiratory therapists with the face shields I'm making
EDIT: 4/7/2020 - Well ... for some reason, tonight, NIH has moved this model to the under review section. The notes are the same and there is no reason listed. I think it might be an error

If you are printing the re-mixed Stratasys face shield on the NIH site here are some tips on the shield & the holes:

NIH Shield project is here - https://3dprint.nih.gov/discover/3dpx-013421

If you don't have laser cutting equipment, or some other cool way to CNC cut the shield material use the file there. The NIH one does not have the logo. I think that's actually better from a cleaning & re-use perspective.

The file on the NIH page has a slight modification to the last hook over the Stratasys shield with the logo that's on the Stratsys Site. This is to make it easier for those of without the laser cutting capabilities, like me.

It's got a small protrusion on the right hook (as you are looking at the front of the visor. The other hooks appear to have a smaller slot for the shield material and the hook seems a tiny bit shorter. This allows a standard three hole desk top punch (U.S.) to be used to punch the holes and the holes are tight enough. Actually still requires a good tug on the last hole.

The shield material should be cut to 8" x 12". Punch the 12" side.

Start putting the shield on by hooking the shield on the left most hook (as you are facing the front of the visor), then the center, then pull it over the last one with the back side protrusion.

My first two dozen plus go to my wife's respiratory care department today. I'll post back with results. She took one visor over the other day and everyone liked the fit. I'm printing with PLA. I'm wondering if it will be more durable than the PETG.

I've got enough stuff on the way for 700 plus of these and maybe 50 of the Budmen shields. Maybe more if I ration the foam. Hopefully I'm taking one hospital off the want list for faceshields.


I started with the Cura built in low resolution settings
Machine - Creality CR10S Pro (about a year old)
I'm printing @ 230C (my machine might be out of calibration)
.3mm layer height
.4mm line width
First layer @ 240C
First layer speed 70 mm/s
First layer flow 150%
Print speed 90 mm/s
Two bottom layers
Four top layers
10% fill EDIT: Switched to 20% fill. Top of the visor is much tighter now. Added ~20 minutes.
Walls - 2 rows
Travel I think is set to 95 or 100, my machine was making funny noises at 145.

I did my own 2 up layout in Cura. Just open two, rotate & reposition the 2nd one so they are back to back. I've got a Creality CR10S Pro so I have plenty of room. Taking ~2:40 to print two.

Good luck everyone! Stay safe. Might be a really interesting week.


Monday, March 30, 2020

Printing Face Shields - COVID Entry #7


Starting to print face shields. First one will be a learning piece. 2nd one should be good. 



Sunday, March 29, 2020

Why I'm Not Rushing To Crank Out DIY Products - COVID-19 Entry #6

This article sums it up pretty well - Do No Harm

I'm concerned that 3D printed masks are no better than sewn fabric masks and will ultimately be more difficult to keep clean. Fabric masks can be washed with bleach, done. There's some research to support this.

I think 3dP face shields represent a better application of the tech, will help, and are far less likely to create other issues as unapproved devices.

Also, health care workers and their organizations need to feel comfortable with the product.

I've asked my wife, who is a respiratory therapist, to show some face shield designs to her people at work. If we can get acceptance for one, great. I can start making some and see where it goes. If one hospital in the Bay Area goes for it then maybe we have a project we can pull people into and scale up. We shall see.

Saturday, March 28, 2020

Sterilization Techniques from a FB post - Entry #5

From the FB group Open Source COVID19 Medical Supplies - Entry #5:

EDIT: This stuff is hard! Bleach and hydrogen peroxide seem to be the best bets for DIY projects.

Hey guys, I've worked in medical device design and manufacturing for almost 20 years. I've also performed sterilization validations for many medical products. While I can't endorse any specifc methods used here, I wanted to provide some basic info and be available as a resource. I'll edit this post later to be more comprehensive

The most common methods are also probably the most out of reach to the DIY community:

Radiation sterilization (see ISO 11137)
- gamma irradiation (typically 25 kGy does the trick)
- electron beam radiation (typically 25kGy as well)

Gas exposure (see ISO 11135)

- ethylene oxide gas (this gas is very toxic so special chambers are needed)

Now for the more attainable methods:

- liquid chemical sterilization (ISO 14161)

- this is typically a peroxide of some sort but higher concentration than you can buy at the store

- moist heat sterilization aka autoclave (ISO 17665)

- dry heat sterilization aka your oven (ISO 20857)

The methods listed above are the most common but there are other 'non-traditional' methods as well.

The key to sterilization in med device is knowing your bioburden level going into the process. With this info you develop your cycle to achieve a sterilty assurance level (SAL) of 10^-6. This means an acceptable risk is that one out of a million devices sterilized might be non sterile. This limit is generally recognized by the FDA as acceptable for implants. For non implants it can be SAL 10^-3 or one in one thousand. The latter applies to things like face masks and tongue depressors and such.

UV sterilization isn't really a thing, it works on surfaces only. This is typically used in cell culture hoods with a built in bulb to keep the interior sterile but it does not give a similar assurance level as the med device sterilization methods.

I've worked primarily on implantable products which will require the above type methods. I would imagine that life saving equipment or components (like ventilator valves) would need a similar approach, but something like facemasks could be easily cleaned with surface disinfectants or UV exposure.

I am looking for any way to help so if you have questions please ask.

Kind regards, Ben

3D Printing & DIY Links for PPE COVID entry #4

Starting a page with some links to folks working on 3D Printing & other DIY PPE projects. I'm focussing on projects that have involvement with health care professionals and/or organizations. This is as much so I have as much in one place as it is for anyone stumbling across this.

There's not much sense in doing any of these unless someone can and will actually use them in a clinical setting.

I'm trying to make some sense out of everything that's going on. Three things are clear to me:

  1. There are plenty of great designs out there and more on the way
  2. I need to find people who will use the products as they are mostly not officially sanctioned yet
  3. Any significant project needs space*
*I think the space issue might be solved by finding companies willing to allow a group to use it's offices. I know in the bay area there are a lot of empty eating & gathering areas right now that would be fine for 3D printing, sewing masks, light assembly, and packaging.


(I'll tidy this up as I go, maybe ...)

NIH 3dP Site With Clinically Reviewed Designs


Things people are making:

Budmen Faceshield - The one you've seen on TV the most I suspect

Lowell Makes N95 Substitute & You Tube assembly video

Emergency Ventilator, I think from France

The Olson Mask & You Tube tutorial - Sewn fabric and HEPA filter media. They are asking for help in making the fabric part.

HPs Site -w- some links to some of the open source projects

GetUsPPE Maker Page

Prusa Printer Stuff:
  • PRUSA Printers - A bunch of uploads Some appear to be approved by some organizations
  • PRUSA strap - 'Cause apparently people are having trouble getting elastic
DIY PAPR by Emory critical care Fellow

Bacon Doctor - Mask made out of HEPA vacuum bags

How to make a mask by Deaconess health. Also seem to be trying to organize makers.

GLIA Faceshield designed by a Canadian ER worker

Big collection of projects that need to be vetted @ cults3d

Phoebe DIY Fabric Mask - with fabric recommendations and production flow suggestions

Kaiser's preferred mask how to - with fabric recommendations

John Muir Health's preferred mask instructions - with fabric recommendations

Projects & communities (sorta, I guess)

FormLabs project pages


Studies on DIY medical products

Mar 2020 Chinese study on effectiveness of N95 -vs- cloth surgical masks for protection agains influenza. Spoiler alert! No significant difference.

Industrial Process References

Non Woven Fabric #1 - Video

Non Woven Fabric #2 - Video -w- kinda loud music.

Non Woven Fabric #3 -Video, loud machine sounds

N95 Mask Welding #1 - Video

Right, if that stuff is making into N95s how does it get sterilized?

Sunday, March 22, 2020

Social Distancing? COVID-19 Blog Entry #3

Home Depot, San Leandro, 3/22/2020
I made a futile attempt this morning to get a few things. We're running a little low on paper towels and like everyone else I'm anxious about supply completely drying up as the cases in the U.S. ramp up. I'm also saving the 91% Isopropyl alcohol we have from before for hand sanitizer so I wanted some more for wound care.

The trip was as much about assessing the situation at local big box retail as it was about getting things. I'm trying to plan in the face of entire systems we can no longer predict or count on. Very unsettling. We're going to need to restock at some point. I'm trying to figure out how that's going to work.

I hit two Wal*Marts, Home Depot, and Walgreens. Yesterday I tried a Target & another Walgreens. I've not tried lining up at opening which seems to be the only way I'm going to get the stuff in high demand. Really, really want to avoid that.

Today I managed to find some 71% alcohol, another bottle of hand soap, and I got some Zip Lock bags 'cause we're running low. Grabbed some Clorox foaming bleach cleaner too. There are NO paper towels or TP.

Bottled water was back in stock, by the pallet, and there was not a run on it. Food seems to be pretty much okay with a few exceptions like pasta in some stores.

Did pretty well on the social distancing. Wal*Mart was okay when I got there. People started to show up after I got there and the health care product section was getting tighter than I wanted so I left. Home Depot was nearly empty. I stopped at a Walgreens too. Again nearly empty. They had tape on the ground at the register line to help keep distancing. I was in and out of Walgreens so no issues.

That said I think it's really, really hard to strictly practice social distancing. The aisles in stores are not twelve feet wide. There's not room to line up at the registers if there's a crowd. Go to the newest stores you can. They will have more room to spread out.

Next time I go out I think it'll be time to put on the shop respirator with the P100 filters and my googles and deal with the lack of social distancing. What if someone sneezes on me? I don't know.

As for the public scoldings going on about people going out. Fair, but, we do need to get stuff. With the supply chain the way it is right now it's hard to figure out what to do. We have TP for a while, yeah. Based on what I've seen the past couple of days it's not going to be there if I let it run out. Do I wait? Do I keep trying? Amazon & other online sellers are NO help right now, at all.

Do the best you can folks. I think we're going to be in this mess until at least July.

Saturday, March 21, 2020

21-Mar-2020 JW's COVID-19 Blog Entry #2

See the entry below with links for data from various sources. As I become aware of more I'll try to update that if anyone is watching ... no promises.

I'm located in Oakland California. I've been working from home (WFH) now since a week ago yesterday, Friday. My wife is a respiratory therapist at a local 200 bed hospital & trauma center. We have adult children living with us so we are tripping over each other at this point, yeah. We are in Alameda county, one of the first six counties nationally to issue a stay at home order.

Today's status, my version:

Well ... as of today as you may know:

  • Italy & EU are still seeing a lot of new cases
  • UK is beginning to ramp pretty seriously
  • New York city and by extension the surrounding area has become the epicenter of the U.S.; replacing Washington state, notably on the polar opposite end of the country
  • Florida has finally begun to shut down the beaches
  • California, New York, and Illinois have issued state wide stay at home orders
  • Production in China is said to have returned to 50% - 60% of normal & trucking is returning, albeit slowly it sounds like, as local & regional travel restrictions begin to lift
  • Shipping world wide is a bottle neck as passenger flights that normally also carry a lot of cargo have virtually stopped
  • Agility indicates that flights are being chartered now to compensate for the lack of regularly scheduled commercial flights
  • All of the data indicates people are recovering from this at a far greater pace then some are unfortunately dying
  • A LOT of people are getting seriously ill and dying
  • Masks and other PPE are running out, every functional ventilator is existence seems to be coming out of the wood work, industry is being asked to engage in making products they don't normally make, like vents and regulations are being eased to allow that to happen.
  • The financial markets are completely screwed up. A lot of people think they are oversold. It's hard to buy in right now because every technical support point has been blown right by. 
  • Hopes for a "V shaped recovery" are starting to fade. Consumers are running out of money fast. The text book "marginal producers" are starting to fall off the margin into BK or worse. 
Holy crap that's a lot going one at once! No wonder people are freaking out.

How long is this going to go on? (Hell if I know but here's a shot at it ... )

So what's this telling us non-science people about how long this is going to take? Let's talk about China because that's the only model we have right now.

It been about five, going on six weeks since China locked it down and it's not over. I believe the lock down began after the Chinese New Year which was on Feb 12, feel free to call me on that. Hubei province is still pretty much locked down. 

China started relaxing the controls about a week ago, maybe two. 

The incubation period on COVID-19 is believed to have a median I'll say of two weeks, right? So if they are going to see a second wave, it'll start end of next week or the week after. 

If you look at the WHO & Johns Hopkins data they are showing a very slight increase in cases in the Western Pacific and China over the past few days. That could be noise right now. 

If the cases stay flat in China for another three weeks (two weeks + another two weeks to be safe), they start to open up Hubei over the next two to three weeks after that, and they still stay flat, then, maybe we begin to have a model for the time for an entire region to recover. My little model there says that duration from shutdown to re-open would be 10 - 12 weeks. 

So in the U.S. maybe we are back open for business by June 15th? Let's say July 4th for the sake of American romanticism. 

Whadya think folks. July 4th?

Now then, who's got enough toilet paper, hand sanitizer, and bleach wipes to last until July 4th? 

More importantly what are folks going to do who work paycheck to paycheck?





COVID-19 Links - COVID-19 Blog Entry #1

Hopefully this helps y'all out. We're getting B.S. & dumbed down information from all the media sources and our governments. They are trying to manipulate our behavior & prevent panic by shaping messages.  I get it. They feel it's their jobs and some have agendas they want to push. I personally just do better with more facts.

NOTE: Even these sources can have some political spin. At least, they are one or two levels closer to what's going on.

Link to Agility's COVID-19 operational updates. Agility is a logistics coordination / facilitation / consulting company.

WHO Situation Reports - Daily reports with a couple of good graphics on daily case counts. Good links to other WHO resources. Daily WHO commentary on the global situation.

EU WHO Dashboard

Johns Hopkins Dashboard - In the upper right of each panel is a control that will full page the panel and return the panel back to the dashboard.

Worldometer's Cornovirus Section - A few different views of the same data you're getting from other places.

NYT Charts - More U.S. oriented representations of the data.

CDC - For the sake of completeness I guess I should include the CDC site ... not impressed BTW, kinda dumbed down.

Italian Ministry of Health COVID-19 Dashboard

UK NHS Dashboard

Irish Health Service COVID-19 Page (no data as of 3/21, probably a good thing!)



Sunday, April 10, 2016

A falcon returns to the nest


SpaceX Falcon 9

Last Friday a bit of a tech miracle occurred. No, it wasn't that iTunes fixed it's music selection algorithms; much to my personal dismay. It was that these guys  landed a big ass rocket on a barge that was barely bigger than the rocket.  Total Buck Rodgers stuff here folks! See the video below.

They also completed the first half of their eighth (?) supply mission to the international space station (ISS). That should have been impressive enough for a company that was founded in 2002 by a software geek. Albeit a very rich software geek. While he gets a lot of credit there are 4000 human beings making this stuff possible at that company. They have come together in fourteen years to accomplish something we have not seen since the Saturn & Apollo programs in the '60s & '70s, and tiny bit more.

What's the more part? Apollo landed on the moon right? How do you beat that? Okay, maybe this isn't a moon landing but it proves in a technology that is going to make a Mars landing far more likely.

Seriously, this really was amazing. The Falcon 9 rocket stuck the landing on it's drone "ship" in the middle of a pitching sea and what had to be 25 - 30 mph winds after successfully propelling the Dragon and it's 2nd stage booster over half way into orbit. Really, check out the video. It's short. Someone was good enough to clip out the landing bit.

Yes, this was their third attempt at full scale. Third time is a charm I guess? Many other people have taken far more attempts to get revolutionary technologies right.

Yes, others have also attempted this and I am sure these folks relied heavily on that work. Still, they did it.

It opens up an entirely new way of looking at the utility of space flight. Up until Friday everyone accepted that the main booster of a launch vehicle was destined to become burned & twisted bits scattered across the ocean somewhere. Or worse, floating about in orbit if they made it that far. Now it is possible to recover the primary booster section. If that's possible then the getting the second stage back is also possible. If you check out the current 2016 sticker price of a Falcon 9 launch, it's a little north of $61 million. Who knows how much recovery will cut that price, but even if it's 30% that's a crap load of money. If that $61 million comes down to $40 million you've got a program that is well within the reach of large corporations with designs on space. DeBeers comes to mind immediately. There are lots of exotic materials to be had for the price of getting there and back in space.

If you can, take the half hour to watch the full video (37 minute).

What about the implications for a Mars mission? If you watch the whole video you'll hear they did something truly from Buck Rodgers on this. They fired the engines to slow re-entry of the Falcon 9 first stage. I believe they used the main engines at that.  If they can do that against the gravitational pull of earth, then Mars is totally possible.

The problem with landing people on Mars is that we are fragile. We don't have the tools on Mars we have on earth, like our atmosphere and lots of water, right? How do you slow a ship down to a human safe speed -vs- a robot safe speed?

Mars does have a thin atmosphere and 1/3 of the gravity of Earth; offsetting factors. But, it's got double the gravity of the moon. Seems to me that engines are going to be part of what's needed to land a large vehicle on Mars. Falcon 9 has proven a large spacecraft can land with rockets alone. This gives engineers a proven method to include in a Mars lander carrying people -vs- just machines.

Well, if you stuck with me until here, thanks! Finally, BRAVO to the entire team at SpaceX! Also a big thank you to Elon Musk for being a true, brave innovator in a world filled with people satisfied with baby steps. We need leadership like this to help us reach our full potential as humans.

Mr. Musk and team join the ranks of DaVinci, Howard Hughes, Tesla,  Edison,  Watt and others who have delivered technology that has changed the world. Keep it up

Wednesday, November 23, 2011

Says it all


Wednesday, March 23, 2011

The Social Network - Belated Review

Finally watched The Social Network on On Demand last night. As an old nerd whose been around the Internet since before WWW, just before, it seemed perfectly real and plausible to me.

What struck me the most was the total lack of real attention to the technology that was unfolding all around the development of Facebook. Which is fine, that would have made it ultra boring for most. Let's face it writing code is not Apollo 13 or Top Gun stuff. Both those films brought us incredible amounts of insight into the technology at work while keeping it exciting.

There were enough techno geek secret phrases woven in to make it interesting. The comment about "Mark Zuckerberg Productions" being on every page by one of the Winklevoss brothers was an interesting way to point our their lack of technical knowledge. In reality that represents one line of code in one file. Anyone who has done any web programming at all knows that. Zuckerberg's rant about up time when Eduardo freezes the account was an Apollo 13 moment; something everyone gets, with a significant underlying meaning for the geek elite. The statement that Facebook NEVER goes down is huge. If he really said that and really operates that way, he's got a view that is rare in "the cloud". Google should take note. Then there was the cavalier move by Sean Parker when he set not one, but two drinks on a laptop at the development center party house. Few self respecting programmers would pull such a move. That machine is your most precious tool. I took that as an expression of Parker's arrogance not only towards people, but towards the very technology that was about to make him rich.

But the movie was not really about technology. It was mostly about people, how they behave, Zuckerberg's ability to see that, his willingness to exploit our behavior, as well as his own human blind spots that lead him to all of his troubles and ultimately drive away those closest to him. My perception of Zuckerberg is not bad, at least not because of this movie. I think he was probably obsessed with creating something he really thought could work. That kind of obsession can cause an insensitivity that appears directed and intentional, but it's not. He was just a coder on a mission.

I would like to see a more documentary edition with the back story provided by the people who were really involved.

Monday, March 14, 2011

Small Scale Testing For Biogas

After sleeping on this, I think it might work. However, there are few things I'm worried about:

1.) Production rate & required inputs to make that happen
2.) Smell
3.) Methane capture from the compost pile
4.) Making a generator run for a sustained period

I think this is all going to take tinkering to make it happen. So, it should be done on a small scale basis using cheap stuff like 5 gallon buckets, plastic trash cans, and model airplane engines. If it can be made to work that way, it should work at larger scale, better. These things get more efficient with size.

I did have an experience with the composting. When I was in jr. high I decided to try to raise worms. It was my first attempt at producing something I could sell. Failed. I put garden soil and mulch in a couple of trash cans. I drilled a bunch of little holes all over the trash cans to let in air. Logical to me at the time. They sat in the basement. After a few days they got hot. Had to be over 120. That killed the worms. Out of paper route money and not having a clue what happened I gave up. Now I can see I had set up the perfect composter. For worms I needed less organic material and more dirt. For composting it was great. That probably helped heat the basement all winter that year. It was an old drafty basement so who knows how much methane there was.

There was no hydrogen sulfide as there was no rotten egg smell. I'm sure adding in some sulfur would have done the trick there!

So .. a 30 gallon Rubbermaid trash can and some clippings from the yard should work for that just fine.

As I said I think the waste digester will be fine with 5 gallon buckets and such.

Thinking about this, the pressures could be high. Beer brewers and root beer brewers routinely have bottles explode. We are dealing with similar processes.

As for capturing the methane from the composter, I need to research the bio process. I needs air. Air is about 70 / 30 nitrogen / oxygen (plus a lot of other gasses). The carbon and the hydrogen have to be coming from the organic matter and the water. The nitrogen is from the organic matter and the air. The research I've done so far tells me that we get mostly methane and carbon dioxide from the pile. So, if we can meter the air that is introduced, we should be able to control the dilution of the methane with air.

My initial thoughts now are that the methane and carbon dioxide can be separated in a column under low pressure. They have different molecular weights so they should separate. I think. Both are heavier than air. We also might be able to find some membrane materials that will allow us to make a separation system.

Later,
John

Sunday, March 13, 2011

Compost / Bio Waste Digesters

There are a ton of projects on YouTube. Like this one. Most are not as nice. So I get that the liquid comes off, I'm a little concerned about the sludge. I don't see folks talking about cleaning these things out. Is everything digested? I can't believe that.

It also seems like some of them are capable of producing a good bit of pressure. That's good as the available engine conversion kits assume some pressure. Stoves need some pressure as well. More research is needed.

Mother Earth News uh "Reprint"

I just don't want to lose this.

Source - http://www.motherearthnews.com/Nature-Community/1972-11-01/The-Plowboy-Interview-Ram-Bux-Singh.aspx


Ram Bux Singh - Gobar Methane Gas Research

By Ram Bux Singh

It is now quite apparent that the days of unlimited and constantly increasing consumption of fossil fuels are "all over but the shoutin' ".

We maul and tear whole states with monster shovels, feed the coal we uncover to voracious power plants that belch out sun-darkening clouds of pollution, distribute the electricity that results through thousands of miles of ugly pylons and cables . . . and still watch our cancerous cities suffer an increasing number of "brown outs" and complete power failures each year.

Even the major oil companies (which have a vested interest in making us believe that the wild ride can go on and on) now ration their dwindling stocks of natural gas and predict that the world's reserves of petroleum will be exhausted in 30 to 50 years.

Clearly, something must be done . . . and most concerned environmentalists find it difficult to believe that the "something" is the development of nuclear power. At least not as long as the AEC stupidly continues to promote the fission process with its built-in dangers of runaway reactors, thermal and radioactive pollution. And fusion? Well, yes . . . maybe. But that approach to the controlled and sustained harnessing of nuclear energy is still only a dream.

Damn it, what we (and the planet) really need—first and foremost—is less instead of more: less human population and less per-capita consumption of power and the things wemanufacture with it. Secondly—and just as important—we must instigate an immediate crash program of research into ways of utilizing solar, wind, water, wave and other natural sources of the energy we do use. And that research must be relentlessly directed away from the development of centralized, capital-heavy, tightly controlled, "dirty" energy systems . . . and toward the nurturing of decentralized, inexpensive, controlled-by-individuals-at-point-of-use, "clean" power sources.

It's a tall order but, luckily, some good men have accepted the challenge. A few have even successfully demonstrated alternative sources of energy that both satisfy all the stringent requirements laid down in the paragraph above . . . and work. One of those men is Ram Bux Singh.

For almost 18 years, Ram Bux Singh has directed experiments at the Gobar ("gobar" is Hindi for "cow dung') Gas Research Station at Ajitmal in northern India. His primary responsibility there has been the development of low-cost and simplified digesters designed to convert plant and animal waste into composted fertilizer and methane for fuel.

In the course of his work, Singh has personally overseen the construction of at least 200 "bio-gas" digesters and has become possibly the planet's foremost authority on the construction of village and farm-sized waste processing units.

Ram Bux Singh's fame spread to this country only recently when a few dedicated ecology enthusiasts began combing the world's literature for information about natural and nonpolluting power sources. Eventually they discovered Singh's work with village and farm-generated methane—which is as natural and non-polluting as a compost pile—and called it to the attention of such U.S. publications as the WHOLE EARTH CATALOG and THE MOTHER EARTH NEWS. As a result of articles appearing in those periodicals, Mr. Singh now receives as many as 10 letters a day from the United States . . . all asking for more information about his experiments.

Thanks, in part, to his correspondence with individuals, government officials and universities in this country, Ram Bux Singh has developed a keen interest in helping to design, construct and promote the use of bio-gas plants here in the United States. "Two billion tons of manure is wasted annually in the U.S., " he says, "and that is actual food and actual power that you could save with the inexpensive composters we have developed in India. "

When MOTHER learned that Mr. Singh was visiting this country last summer, she immediately invited him to her Madison Ohio location to direct some of her people in the construction of a homestead-size bio-gas plant. MOTHER's staff found Ram Bux Singh to be an intelligent, alert, highly personable and extremely capable gentleman and they enjoyed his visit immensely. Mr. Singh speaks four languages—Hindi, English, Urdu and Persian—and (lucky for MOTHER) the following interview was conducted in English shortly after THE MOTHER EARTH NEWS' prototype methane generator was completed.

PLOWBOY: Ram Bux Singh, thanks largely to the WHOLE EARTH CATALOG and THE MOTHER EARTH NEWS, your efforts to convert manure and other natural wastes into methane have become fairly well known here in the United States. Did you originate the idea of producing non-polluting fuel from such sources?

RAM BUX SINGH: Oh no. The idea of taking out the gas from farm waste, vegetable waste even human excreta is very old and was demonstrated at an exhibition in London in 1871. In 1905 a very large plant designed to produce both gas and good fertilizer from waste was installed in Bombay, India. Then, during World War Two due to the shortage of conventional fuels, the Germans built many bio-gas plants for both the fertilizer and the methane that the digesters would make. They compressed the gas and used it for driving tractors and farm machinery. The idea is not a new one.

Today in Algeria, in South Africa, in Korea, in France, in Hungary and in many other countries thousands of bio-gas plants are in use. The idea does not belong to me or to the government of India.

PLOWBOY: But you have been experimenting with methane conversion for some time and your work in the field is considered quite important by scientists and technicians all over the world. Obviously you've contributed something of value to the search for ways to recycle waste into non-polluting fuel.

RAM BUX SINGH: Yes, I have worked on this problem for some time. In 1955, the government of India appointed me to simplify the construction of bio-gas plants. There was no question that such units would produce methane but, up to that time, most gas generators were very large and costly. Even the small plants built in Germany during the war were quite expensive. So what we have done at the Gobar Gas Research Station in India is to simplify the construction of bio-gas generators. We have designed efficient plants that are small enough for a single village or one farmer to build and we have found ways to construct these gas generators for very little money. We have made the bio-gas plant economical for small farms.

Let me give you an example of what we have done. When recently visited a sewage plant at Charleston, West Virginia, the engineer there told me that seventy million dollars had been spent on the facility. If we were to try to scale down to: village or farm size the technology used in that plant, the smaller waste disposal unit might still cost half a million dollars Now, no village in India and no farmer even in the United States is going to spend a half million dollars to process waste. But we have designed bio-gas plants which both purify waste and produce non-polluting fuel . . . and some of these units can be built for as little as $100! With our designs and a relatively minor investment, then, a farmer or small group of people can now construct a self-contained system that will recycle plant and animal waste into high-quality fertilizer anti non-polluting fuel. The fuel can then be used to cook with, to heat the farmhouse and to power machinery. A bio-gas plant can make a farm more self-contained and independent.

PLOWBOY: In other words, while the radicals talk about it you're really bringing power to the people!

RAM BUX SINGH: Yes.

PLOWBOY: It's this idea of homemade power, you know, that has excited so many people in this country. The idea of running a car or heating a house with non-polluting fuel that is generated from waste right in one's own back yard is tremendously attractive to individuals fed up with oil spills, strip mining and smog. Yet I notice that you emphasize the fertilizer produced by a bio-gas plant just as much as you emphasize the methane which comes from such a unit.

RAM BUX SINGH: Oh yes. The fertilizer is very important, especially in a country like India where the farmers do not have so much money with which to buy chemical plant food. You are rich enough here to purchase the commercial fertilizer and you do not think so much of conserving the natural nutrients for your crops. But I believe you will. As your p opulation increases and you farm more intensively and the movement to cooperate with nature gains strength in the United States, I believe you will think more and more about conserving your natural plant foods. You will begin to think more and more of the bio-gas plant as a source of both power and high-quality fertilizer.

PLOWBOY: What do you mean by "high-quality"?

RAM BUX SINGH: We have calculated through many university lab tests in India that the fertilizer which comes from a bio-gas plant contains three times more nitrogen than the best compost made through open air digestion. If you compost chicken manure, for example, the finished compost will have in it only 1.58 to 2%o nitrogen. The same manure digested in a bio-gas plant will analyze 6% nitrogen.

PLOWBOY: Where does this extra nitrogen come from?

RAM BUX SINGH: It is already in the manure. The nitrogen is preserved when waste is digested in an enclosed bio-gas plant, whereas the same nitrogen evaporates away as ammonia during open air composting. The bio-gas plant does not make extra nitrogen; it does not create nitrogen . . . it merely preserves the nitrogen that is already there.

PLOWBOY: OK. I can see how the nitrogen is caught and contained when plant and animal waste is digested inside a closed bio-gas plant, but what about other elements? Is anything lost or eaten up by the bacteria in the tank? Do they take anything out of the organic material so that, over a period of years, you'll be putting back less and less on the fields you fertilize with waste processed in a bio-gas plant?

RAM BUX SINGH: No, nothing is used up. This is the perfect fertilizer-making machine and it has been tested all over the world. There is no better way to digest or compost manure and other organic material than in a bio-gas plant. I think you can compare the bacteria in a digester tank to fish worms. Fish worms help the soil by eating organic matter, passing it through their bodies and expelling it as very rich fertilizer. They live by breaking waste material down into food for plants. It is the same with the bacteria in a methane digester.

PLOWBOY: Yes, that's a good example.

RAM BUX SINGH: You may also think of it another way. Seven cubic feet of methane gas can be generated from one pound of dry leaves but only one cubic foot of gas will come from one pound of cow dung. The cow dung, on the other hand; is just that much richer a fertilizer than the leaves. You can say, then, that the cow has digested the leaves and partly turned them into plant food. When the cow manure is then composted in a bio-gas plant, the bacteria there merely further process or refine the former dry leaves into a still richer plant food. It is all very natural.

PLOWBOY: We've heard much about your experiments with cow manure at the Gobar Gas Research Station in India. Have you successfully processed other kinds of waste?

RAM BUX SINGH: Yes, we have experimented with many types of digesters in India and our most successful work has been with chicken manure. Chicken droppings are easily digested, produce large quantities of methane and when processed make a fertilizer with a very high nitrogen content.

PLOWBOY: What about human waste?

RAM BUX SINGH: Human excreta is very rich and should produce much gas and very good fertilizer. The two or three plants we have set up for processing this waste have not been successful, however, because of the modern flush toilet. There is just too much water with the excreta . . . too much liquid for the digesters to handle. If we could separate the water from the human waste, though, I think we would find our own excreta to be the very best of all for recycling into fuel and fertilizer.

PLOWBOY: Over and above our excreta our personal waste have you experimented with human waste in general? Have you built a plant to handle all the garbage and waste paper and other sewage that people generate every day?

RAM BUX SINGH: Yes, we have built plants of that type . . . sewage plants with the primary purpose of not to make the gas and not to make the fertilizer but to keep the city environmentally fit. We have done this in many cities in India. The biggest of these installations is in Delhi. There, four 400-horsepower engines are running on the methane from the plant and those engines drive generators which produce electricity. The fertilizer from the sewage plant is given to the farmers in the area.

There is one difficulty also with these installations however, and that is the high percentage of paper and related materials that people discard. This waste is not rich enough in nitrogen and it does not produce a great deal of methane nor does it make the best fertilizer. Too, just like the excreta, this material is usually accompanied by far too much water and it is difficult to digest.

PLOWBOY: You say that the ordinary sewage From a city is not rich enough in nitrogen for best digestion in a bio-gas plant. Isn't there anything you can do about that?

RAM BUX SINGH: Yes, of course. You can seed the mixture before it goes into the plant with nitrogen. Let me explain:

The anaerobic bacteria that do all the work in a bio-gas plant consume carbon about 30 times faster than they use nitrogen. They work most efficiently, then, when the waste fed to them has that balance. When the carbon is 30 parts and the nitrogen is one part, the material put into a bio-gas plant will digest very rapidly and will produce much gas and good fertilizer. Results will not be as good when the carbon-nitrogen proportions are anything else.

For instance, sawdust has no nitrogen at all. Simply carbon is there. If you put nothing but sawdust into a bio-gas plant, it will not digest even in 200 days. But if you add enough nitrogen either naturally, in the form of manure, or chemically to make a 30-to-1 working ratio, the bacteria will rapidly process the mixture into methane and fertilizer.

PLOWBOY: So, for best results, you must analyze the material you put into a bio-gas plant?

RAM BUX SINGH: Exactly. You cannot guess. Many people have written to me that they have installed a plant of a certain size and filled it with so many leaves and so much of this and that . . . and the unit does not produce gas. It does not digest the material. I write back and tell them that they have not calculated the ratio of carbon to nitrogen in the material. When you load a digester with grass, leaves and other high-carbon waste, you must also mix in enough nitrogen to make the material ferment.

In the beginning, if you do not know how much carbon or nitrogen is in the different materials you have to process, you can send samples to the nearest university lab or county agent and have the grass and straw and other matter analyzed. After that, you'll soon learn to judge the percentages.

PLOWBOY: And from then on, it's just a simple chemical reaction.

RAM BUX SINGH: A very, very simple reaction. When a bio-gas digester is properly built, loaded with the correct mixture of carbon and nitrogen and held at the appropriate temperature, there is no difficulty at all. There is no way you can make it not work.

PLOWBOY: What is that "appropriate temperature" you've just mentioned?

RAM BUX SINGH: When a digester loaded with the proper carbon-nitrogen mixture is maintained at 90 to 95° Fahrenheit, in 40 days the material will produce 95% of the gas it is capable of producing.

PLOWBOY: And if you maintain the digester and its contents at, say, 110°F?

RAM BUX SINGH: Yes, you can use 110° . . . even up to 118°F. Above 110, however, much gas will come but the production is not easy to maintain . . . and above 118°, the bacteria will die.

PLOWBOY: Let's say you do use 110°F. What will the digestion time be then?

RAM BUX SINGH: It would come down to about 28 days at that temperature.

PLOWBOY: And how far can we go in the direction of minimum operating temperature?

RAM BUX SINGH: First-class digestion takes place between 90 and 100°F. Between 75 and 90°, a bio-gas plant works . . . but not nearly so well. At 60 to 75°, there is digestion but only very slow production of methane . . . and below 50 or 60°, the whole process is arrested.

PLOWBOY: OK, now. You've just said that a bio-gas plant loaded with a 30-to-1 mixture of carbon and nitrogen will, when held at a temperature of 90 to 95°F, produce 95% of the gas that the waste is capable of generating . . . and will do it in 40 days.

RAM BUX SINGH: Yes.

PLOWBOY: Which brings up the point that—once a definite length of time is established for the digestion of material in a bio-gas plant—the unit can then be operated in either of two ways.

RAM BUX SINGH: Yes. We have designed some bio-gas plants for what we call "batch feeding" and some for "continuous feeding". We can even switch some of our units back and forth from one method of operation to the other.

For the batch cycle, a bio-gas tank is opened and filled with the waste material to be processed. The digester is then sealed and the methane gas collected as the matter inside decomposes. After 40 days, the tank is again opened and the composted fertilizer is taken out. The digester is then filled again and resealed for another cycle. Actually, the tank does not have to be opened if it is designed properly. Instead, with the proper inlet and outlet pipes and a pump, the waste—in slurry form—can be pumped in and out.

With the continuous feeding method, a bio-gas plant is filled once. Then, as the bacteria inside begin to change the waste into methane and fertilizer, new and undigested matter in the amount of one-fortieth of the volume of the tank is added each day. If the digester is properly designed, the digested one-fortieth of the material in the tank will be forced out as the fresh waste is piped in. In this way, new material is constantly added to the mass in the bio-gas plant and spent matter is constantly expelled. The unit, then, steadily consumes waste and just as steadily produces methane and fertilizer.

PLOWBOY: But how do you make such a digester operate so efficiently? How do you make sure that only digested material is forced out as you pump in the fresh matter to be processed?

RAM BUX SINGH: It is very simple. Unprocessed waste is heavy. As the bacteria digest it, the matter becomes lighter and lighter. Merely by positioning the inlet pipe in the bottom of the tank and by placing the outlet at the top of the mass, we use this natural principle to our advantage. The tank can hold only so much and—as we force a small amount of new material into the bottom of the digester every day—a corresponding amount of processed matter is forced to overflow through the outlet.

PLOWBOY: Very clever and very interesting!

RAM BUX SINGH: Yes, and we have taken that idea one step further in our more complex bio-gas digesters. Because we have found, you see, that a really big plant works more efficiently on a 60-day cycle and we have also learned that the material in such a tank gets lighter during its first 30 days of digestion and again heavier during the last 30 days. So we build those big bio-gas plants with both inlet and outlet near the bottom and separated by a wall that goes all the way across the tank.

We operate such a plant by filling the first half once and then, when digestion begins, we pump in fresh material . . . one-sixtieth of the digesting mass' volume. As we force this fresh matter in at the bottom of the first half of the tank, the partly digested material on top flows over the wall into the second section of the plant. There, the waste slowly sinks as its processing is completed until, finally, the completely digested material is forced out the outlet pipe in the bottom of that second half of the tank.

With such a system, approximately 80% of the methane produced comes from the first half of the digester and 20% comes from the second section

PLOWBOY: Yes, and I see here in some of your drawings of those bigger bio-gas plants that you call for rather complicated and expensive-looking heating coils and agitators out in the middle of the tanks.

RAM BUX SINGH: Such mechanisms are necessary in the larger plants. The manure and waste being processed must be warmed and stirred uniformly so that it will all digest at the proper rate.

PLOWBOY: But the small bio-gas plant you've designed for THE MOTHER EARTH NEWS , doesn't have any heating coils or agitators in it.

RAM BUX SINGH: No. They are not necessary in such a little digester. When the jacket around the holding tank is filled with hot water, the material in the main tank will be warmed quite well all the way through. In the same way, this digester is small enough that merely pumping the waste matter in and out of the main chamber will sufficiently agitate the fermenting mass.

PLOWBOY: At that, I understand that MOTHER's bio-gas plant is somewhat more complicated than most of the homestead-sized digesters you install in India

RAM BUX SINGH: Yes. In India, where it is warmer, there is no need to put a water jacket around the main tank and there is no need to wrap a bio-gas plant in insulation. This digester however, has the additional features because it is expressly designed for the colder climate you have here in the northern United States. The additions make it both more complicated and expensive to build than most small bio-gas plants constructed in India.

PLOWBOY: I think you've told some of the people who helped build this plant for MOTHER that it can be operated several ways.

RAM BUX SINGH: It is a batch feed digester but it can also be operated on a daily-feed, a weekly-feed and on a 15-day-feed cycle. We have designed this bio-gas plant to work in many ways so that you may learn about our ideas and report on them in THE MOTHER EARTH NEWS. There is much interest in methane gas production in the United States but, so far, there have been hardly any bio-gas systems built here.

We wanted this one to provide you with as much information as possible.

PLOWBOY: As I understand it, you're setting up THE MOTHER EARTH NEWS digester with a water jacket in which heated water will be circulated to keep the main tank at its optimum temperature of 90-95°F. The design also calls for a heavy duty mud pump—run by a two horsepower electric motor—to force the waste material into the bio-gas plant, to circulate the matter as it ferments there and to push the digested material out of the tank.

RAM BUX SINGH: Yes, that is correct.

PLOWBOY: Well, it's going to take some energy to heat that water and run the pump. Will the methane generated in the plant be worth it?

RAM BUX SINGH: Oh, yes. Each month, this plant should make about 6,000 cubic feet of methane. The digesting material needs to be stirred only 20 minutes a day or a total each month of about 10 hours. Since a gasoline engine consumes 18 cubic feet of' methane per horsepower per hour, the two-horsepower engine necessary to drive this bio-gas installation's pump will use about 360 cubic feet of the gas each month. If we were to fuel the hot water heater with methane, we would find that the gas it consumes would be much less than this . . . we could even cut that further by warming the water jacket with waste heat from the engine. In all, we should net more than 5,000 cubic feet of methane and much valuable fertilizer from this plant every month. A generator like this one should pay for its initial investment in three years.

PLOWBOY: And just how good will this methane be?

RAM BUX SINGH: In India, when we process cow dung in a biogas plant, the methane that results tests about 650 BTU per cubic foot. I think it will be higher in this country because you feed your cattle so much grain. I think it will be also higher here in the United States because your cow manure from the barn is already in a slurry and contains the urine, whereas—in India—the cow dung we use is dry.

PLOWBOY: Well, let's just say that we do as well as you do in India. Let's say we generate methane with a value of only 650 BTU per cubic foot. How does that compare to the natural gas that is piped out of the ground for heating, cooking and industrial use?

RAM BUX SINGH: Natural gas, in this country, is about 1100 to 1200 BTU per cubic foot.

PLOWBOY: So the methane from a bio-gas plant is only about half as efficient as the natural gas we buy.

RAM BUX SINGH: Yes, but that is not bad. In England, for example, they take a low-grade coal and process it into coal gas which is then piped into factories and homes as fuel. This coal gas is a very important source of power in England at this time, yet it only has a BTU rating of 450. The methane from a bio-gas plant, then, is one-and-one-half times more efficient than that.

But even this is not the important point. The important thing to remember is that, in England, they are going to the trouble to process the coal into gas with a BTU value of 450 . . . while, in this country, you are making really no effort to save and use the 650-BTU gas that is evaporating and going to waste on every farm.

PLOWBOY: Well, we're making the effort now . . . that's why we have you here!

RAM BUX SINGH: Yes.

PLOWBOY: Actually, it goes past even the methane and fertilizer we're wasting on the farms. I believe you're working on plans for a prefabbed bio !gas plant that can be be installed in city houses.

RAM BUX SINGH: Yes. Much real and potential energy goes to waste even in the cities of the United States. I here is all the garbage—the vegetable trimmings, the spoiled food, the leftovers—that most families have. There is the dung from pets and the human excreta. The grass clippings, the weeds and the leaves. All this cyan be composted into much usable methane and fertilizer.

There is also other waste that could be used to operate a bio-gas plant. For example, the average temperature of bath water is 150 to 180°F. Even after use, the water has a temperature of 110° and, in the United States, you use about four to six cubic feet of this water per person per day. If you were to run this spent water into the jacket of a digester, it would warm the bio-gas plant to its optimum operating temperature and keep it there at absolutely no cost.

PLOWBOY: But what if everyone takes their bath in the morning or only once every two or three days?

RAM BUX SINGH: It makes no difference. If the bio-gas plant is properly insulated; it will need this hot water only once every 72 hours. The spent bath water alone is enough to heat the plant.

PLOWBOY: That makes a lot of sense. By recycling city wastes the way you suggest, we could go a long way toward making our lives more enjoyable while we preserve the planet's resources and drastically curb the way we pollute.

RAM BUX SINGH: Yes. That's why I would like to work with a factory in this country to develop and mass-produce a series of prefabbed digesters that people could buy and install and put into use quite easily. One of these bio-gas plants should be heavily insulated for your northern states and the other could be designed less expensively for your hotter climates. Both digesters should be available in two or three sizes. With only a little work, a manufacturer could develop a line of bio-gas plants that would sell quite well in this country. If any factory owner wants to manufacture these plants, I will work with him and help him to do it.

PLOWBOY: And in the meantime?

RAM BUX SINGH: In the meantime, I am getting five, six, seven . . . even ten letters a day in India sent to me from the United States. These are letters from people who want to know how to build and operate a bio-gas plant . . . from people who want to buy my books on the subject. I answer the letters and send the books, but it takes much of my time and the mail from India to here is often slow and the books are sometimes lost.

I would like it if soon a book written by me should be published by THE MOTHER EARTH NEWS. Then you can answer those letters and make the book available here and help the people in this country to learn about the bio-gas plants.

PLOWBOY: We'll publish that book, Ram Bux Singh; just as soon as we can. For the present, though, we'll have to 'be content to test the digester you've helped us build and to continue reporting on your work in our magazine.

RAM BUX SINGH: That is very good. Thank you.

PLOWBOY: And thank you, sir.

Thinking about composting and micro generation

Before I go on, let me address the alternative fuel Nazis. Yes, what I am proposing is not ultimately sustainable in the short term. We need stop gaps. It took us hundreds of years to develop our addiction to fossil fuel. It may take longer to get off it.

Most cities today get their power from far away. It seems we lose at least 30% due to line loss. See this link for an explanation of line loss. That author says up to 30%. I'm going with more because of the local connections, transformers, overloaded wires, etc.

Most houses receive a good supply of natural gas that could be used to generate power at the source. This would bey definition be 30% more efficient or better. Efficient small internal combustion engines are available now. Small gas turbines are available for quantities appropriate to office buildings. Sterling engines have been a twinkle in the eyes of many eco-friendly energy generation buffs for a long time. Small diesel engines are also there and can be run on natural gas.

Technology is changing as well. These small, efficient internal combustion engines were non-existent 20 years ago. Rising fuel prices and EPA regulation have pushed that technology along. I suspect if there was a demand for really, really efficient micro generation, it might advance even more.

The bonus here is that a natural gas fueled residential micro generator could be partially or even fully powered by methane recovered from composting. The size and efficiency of the composting operation is the only limit.

Additionally, heat recovered from the composter can be used to directly heat the home or heat water to a level suitable for showers and baths. The composter could be used to preheat water for dish washing or other sanitary uses.

Now let me address the "no way will it pay back" zealots. Return on investment and total cost of ownership has to do with time and technology. We should have all learned by now that durable products have good payback over time. We should have also learned that over time, technology improves everything. Also, over time, old commodities that were once plentiful and cheap become constrained and expensive. Oil prices are headed north of $100.00 / barrel again. The reasons, in the long term, are persistent. The biggest reason, economic development in the "3rd world", has just begun to surface. Pay back is about to become a back of the cocktail napkin equation.

My probable design

How Big ???
A guy named Jean Pain did this in 1980 with a 200 ton composting pile. He supplied all the heating and power for his home and ran his truck with the methane. These guys were getting 1000 btu / hr per ton of active compost to be used for heating. Their pile was 220 tons.

The material density is highly variable obviously. Jean Pain said it was 40lbs / cu ft. wet. That's about the density of douglas fir lumber. As a check 10 tons is then 500 cu. ft.


If I get 1000 btu / hr then well have 240,000 btu / day.

Our furnace is 66,000 btu. So the composter could theoretically compensate for it running for 3.5 hours. That seems like way more than it runs. Need an hour meter. Anyway, 10 tons of compost could heat the house. Further research seems to be needed.

Composting time seems to depend on how much decomposition you are after. The New England project seems to have gone for 5 months. Pain seems to have gone up to 18 months. With a continuous top charger, bottom unloader this will equate to a rate of "flow" through the unit. Finding the right rate is going to be a lot of trial & error.

So let's say four containers 5' x 5' x 5'. This would be low enough for Teri to throw stuff into. We might want to make it a series of 10 units 2' x 5' x 5'. Or we could make it tall & skinny. The neighbors might have issues with that, dunno. Modular would allow for an incremental build as well. It's going to take time to do, and time to charge with material. Getting one unit up at a time probably makes some sense.

As I hinted at above, I'm thinking about more of a continuous feed design. I think a top loader with a 45 deg ramped bottom. This will allow us to charge and unload the compost incrementally. Since our green waste production is not going to be in huge amounts like a farm would have.

I'm initially thinking that concrete block construction covered with rigid foam insulation and stucco or siding over that is the way to go. We are trying to conserve heat. I was struck that neither of the projects I found insulated the pile.

I would accomplish heat recovery with copper or stainless pipes running vertically in the stack. Then they'd run under ground into the house.

Heat storage is always interesting on these things. I think a heat exchanger is in here someplace. Using primary water in the recovery system is a bad idea. First we probably want it treated to prevent corrosion & allow for best pump life. (may want to think about that, a leak could kill the pile). Second a break could get compost into the house water supply. Not good. Also a heat exchanger would allow both the hot water system and the forced air system to use the energy.

I think a tank full of water and rocks is probably a good storage medium and could double as the heat exchange vessel. Above ground is probably good for starters until we get this all dialed in. I'll probably have to make it out of fiberglass or find a good used / surplus tank. Need to cover it with a shed to make it look nice. I'll have to do some research to figure out the in flows and out flows of energy.

The storage tank(s) could be modular as well.

So, here's the big mystery to me. The composting process generates methane. Neither process recovers that. Pain uses a digester, presumably with manure or compost, to get gas. The New England process says they could gain efficiencies by recovering the gas, but they don't do it in that project. Dunno yet.

Okay .... well, that's a lot to think about. We'll see if it still makes sense after thought and more research.

Thursday, February 28, 2008

Overglaze

So I'm using some glaze from Duncan Ceramics. I screwed up of course. The directions said:

1. Apply to shelf cone 04 bisque.
2. Fire to shelf cone 06.
3. Clean up with water.
4. For clear glaze application, brush-on or dip clear glaze over Concepts.
5. Stilt and fire to shelf cone 06.
6. Water clean up.

Somewhere in the course of reading stuff, I stumbled upon something about matte or flat underglazes. I made the wrong assumption that all of them are matte. So then it made sense to fire it, apply the clear glaze, then fire it again 2 cones lower.

Well, not so much.

With this system the clear glaze is supposed to go on before firing. Fortunately the underglaze is also OK to fire alone. So the bowl was not wasted.

John

Saturday, February 23, 2008

Cone 04 Firing




Started today at about 11:00 a.m. with the Cone 04 firing. 7 hrs. and 10 minutes later, about 6:00 p.m. the program ended. The cone was just above the shelf and the temp was at 1945 degrees F.

So I am concluding that the thermocouple is properly calibrated and the program is about right. I'm actually very impressed that they wrote these programs so they hit the cone energy values as close as they did.

It's 9:00 p.m. and the temp is down to 618 degrees F. At first is dropped 600 degrees + in the first hour, then slowed. I used to know the formula for this. The rate is logarithmically related to the difference between the temperatures I believe.

The picture here is at the beginning of the cycle. I kept the lid cracked for about 90 minutes. As it approached 500 -600 degrees F I noticed some burning like smell coming out. So the glaze gases something as it gets hot.

I had some trouble positioning the cones. I thought they would be OK. The pictures here show them before I started.








Oh, it rained a little today. The work around is working OK. I discovered I need something like a porch roof. So I need to extend the roof about two feet. I think I'll do this with a light weight 1 inch square tube instead of the 2 inch square tube.

The final solution is going to be an elevated floor in the shed. There's plenty of room for that. That'll make it as weather proof as any building.

Later,
John

Friday, February 22, 2008

Kiln & Rain

The enclosure worked OK but not perfect. There was quite a bit of spatter from the bottom side openings. I did not anticipate it would get in that far or that high. So the bottom of the kiln and the control box were wet.

I'm heating it up to 200 degrees F now and will hold it for a couple hours at that temp. Then I'll try it at like 500 degrees to see what we get.

The temporary fix is to put some aluminum sheet scraps around the bottom to stop the spatter from the falling rain. I'll probably get some magnets to hold them on and cut them to fit tomorrow. Should do the job. That way I can adjust them to still allow air in the bottom.

Later,
John

Thursday, February 21, 2008

Cone melted


Not sure if this is normal or not yet. My wife told me that the cone bent all the way over. When I looked at it in the peep hole I swear it was not bent over yet. I read something about them bending after soaking for a while. So, I wonder if they are just always going to bend and the real measure is the point at when they bend to whatever angle at first. Then they just keep bending. For some reason I got it in my head that they stopped. But that doesn't make sense now.


So Saturday morning I head back over the Aardvark to get some 03, 04, 05, 06, 07 cones. I have a bowl that's coated with glaze. I want to fire it to an 04, then put the clear coat on it and fire it to an 06. I'm planning on using the medium ramp rate just for consistency in testing. The glaze is supposed to be a really dark blue. Hopefully it comes out OK 'cause it's a nice size for an Oatmeal bowl.


I think my wife wants to do some plates too. I think with some additional shelves we can do four plates at once in the kiln. So this should be fun.


Later,

John