Rocket Incinerator?

We live in the country and people burn  *everything* in barrels and brush piles - including plastics and other things that release dangerous chemicals.  
In an ideal world there wouldn't be all these plastics to deal with, but there are and these people are going to burn them, so I'd at least like to be able to offer a cleaner solution.

I would love to figure out a cheap way to build incinerator that:
* Burns at 900° C or higher
* Can take a full, normal sized kitchen trash bag (10 gal)
* Affordable to build

Here are resources I have found so far:
Step by step instructions on how to build a medical waste incinerator
The Incinerator Guide
Standard Solid Waste Management In Camp  The incinerator in this looks large enough, but very expensive to build.
A discussion about a home made incinerator
This one is very interesting  Low – Cost, High – Temperature Waste –Disposal Incinerator: A Prototype in SECMOL  I really wish there would have been a follow-up, but couldn't find one.  They mentioned not being able to seal the door, and with the construction method and materials, I'm not sure how it could be done.

Any experience or ideas?  

Welcome to permies!

It's not the answer to everything, but if you've got a brush pile the hot tip is to light it from the top. The effect is a flame cap burn similar to what we use to make biochar in a pit, bathtub, or kontiki. Now, if there's plastic and other rubbish in the pile you're not going to want to use that for biochar, but the top-lit method makes a hot fire with little smoke (as long as you start with reasonably dry material).

For something more controlled, a rocket combustion "engine" heating a retort full of waste would get up to crazy hot temperatures if you piped the evolved gases back into the burn tunnel. With the right amount of secondary air and turbulence this could be a very clean burn...once again, there are some things I simply would not want to put in it, like heavy metals, but for household type materials it would be way better than a burn barrel. That appears to be what the SECMOL team are doing and that's the direction I would go as well.

We're obviously aiming for "less bad" here, not "ideal."

Since it's SECMOL, we should try paging Rebecca Norman. She might know more about this and if it's been through more development.

Hi! Yep, here I am with an un-edifying follow-up from the incinerator experiment at SECMOL. We did the prototype with Russell Collins of Himalayan Rocket Stoves Australia, Chozang Namgial of Himalayan Rocket Stoves India, and Konchok Norgay director of SECMOL at the time.

I asked Rohit Ranjan, the author, for a follow-up, but we didn't make it a permanent installation. We really should. Here's what I recall with the author's input.

1) We were lucky to have found rolls of dirty ceramic wool discarded in the desert by the Indian army (haha, that's how a lot of garbage goes in the area).

2) The waste inlet was problematic because plastic waste isn't shaped like fuel. It's in awkward shapes, some of them bulky or too compact, etc. I also remember we discussed that some types of plastic melt rather than combusting. It also may need a grill made of high temperature material. So waste inlet design is going to need work.

3) As mentioned in the article, our initial air inlet pipe was insufficient. We were doing this at 10,500 feet above sea level where the air density is very low, so other locations might have less of an issue. Anyway, we were building this with materials on hand at the time.

4) As I recall, the temperature probe was destroyed when we left it in the chimney too long. We'd already gotten several readings at different spots. So if you embark on this type of project, invest in a good high temperature probe first.

Rohit Ranjan's input:

I think you are mostly correct. But what I remember is the following:

1. When the [senior male] staff member would operate it, it worked well. However, when students or junior staff operated it, it just wouldn't work and dense smoke was produced.

2. Additionally, we never quantified how much fuel was needed as starter, and there was always a complaint that the garbage itself wouldn't burn and people needed to supply extra fuel (wood), which was a hassle.
[Rebecca: wood is in super short supply and valued in Ladakh, where even twigs are used for fuel. This should be a surmountable issue in other climates.]

3. People also say that at one point the students put in a lot of sanitary pads for combusting and that was the end of it, or was it for the Phyang one? I am confused now.
[Rebecca: I heard the one in Phyang ended when villagers stuffed it with diapers/ nappies/ Huggies, so that might be what you remember]