Rotary composters?

[julianf]

Where my partner used to work (a school) they had one of these -

It was pretty impressive. All the schools food waste went on one end, with some sawdust, and, each day, a handle turned a few revs at the end.

I think it took somthing like two weeks for the waste to come through, and, when it came out, it looked just like stuff out of a sack from the garden center.

Anyway, she has been wanting a domestic sized one for a while, but the company above is very much geared to public institutions.


I'm wondering how hard it could possibly be to make one?

So far as I could tell, it was a static plastic tube with thermal lagging around the outside, and a shaft with paddles (I guess stainless) on the inside.


Maybe the reason they're only commercial is a function of waste time inside the unit. As in it has to be long otherwise the waste just comes out too soon or somthing? Paddle angle etc is variable on build but waste size is fairly out of control.


Anyway, has anyone built somthing like this?

I'm aware of options which are, basically, a drum on rollers, or a stand but that's not really want I'm on about here. The rotating drum may be easier than the fixed drum though. The key point is that it's insulated (with what, I'm not so sure, as it would be outside in the rain)

Thank you.

 

[Kram]

Have you seen the ones on Gaztube?

 

[gaz1]

and its Gaz1tube



so first off its down to your food waste and pellets or wood chip ratio is 6-1 or 5-1

both systems use paddle mixers just like a cement mixer or screw type of mixer

another post on the subject

How does a hot box compost bin function?

I mean how are they built inside. Basically I am guessing that these items are a steel bin that is insulated. I am unsure how they are insulated, but it is probably just insulation material sandwiched between the outer casing and and an inner metal skin? Having said that, composting needs air...

www.mig-welding.co.uk

 

[S-Rail]

There was a similar on the net where it was made out of a 50 gallon plastic drum with a removable lid. Collar around the centre and used as an axis / axle and set on a stand like a tripod . You just add the goods and give it a couple of tumbles / turns .

You could probably make it for less than £20

Like this … sorry , not sorry for the link ….as it would appear I would be stealing someone else’s thunder …

 

[Alan Reynolds]

I’ve got a barrel composter. It’s inhabited by loads of worms who produce lovely compost in exchange for food. The newts in the pond get a few treats when the worm population gets too large and start eating more than they produce.

 

[gaz1]

the simplest way to make one is to use 2 barrels

a front and rear wheel bearing as they can be fixed internally to the outside fixed stand

the bars and the paddles can be fixed on afterwards

if you want a cheaper one, the car spit is a good reference on first video below link

gearing well use a cars flywheel

Mini spit……

Trawling through here last night I found a thread from way back from a user who seems no longer here. https://www.mig-welding.co.uk/forum/threads/my-wifes-mini-on-homemade-rotisserie.30514/ His spit was made following this site...

www.mig-welding.co.uk

 

[Beeezer]

Snakes can’t lay there eggs in them……..

 

[Bladevane]

I'm going for a trial 45 litre ex food barrel with a resealable lid. In go the contents then roll it on the ground every day or 2. No axles, no lifting, no mechanism. Let's see if that works.

 

[julianf]

I'm going for a trial 45 litre ex food barrel with a resealable lid. In go the contents then roll it on the ground every day or 2. No axles, no lifting, no mechanism. Let's see if that works.

I'm not sure how well it will work if it's well sealed.

It's an aerobic process, which is the whole point of turning - to get the oxygen in.


I don't know how much air is needed though. I mean maybe the 20% when you put the lid on will be enough for the whole job - I really don't know. But if it isn't, then the aerobic part of the process will just stop.


The ridan thing was all open to atmosphere (at least open enough for the gasses to normalise).

The main issue with most of the rolling barrel jobs (and I realise yours is just a test) is that they're batch process rather than continuous.

So then you need a couple of "batch" reactors, to fill one whilst the other is working, and then you need more space etc

 

[Onoff]

I've debated something similar but with a fixed barrel, laying horizontal. Central axle with blades / paddles. Slight difference, I was going to have a biogas take off at the apex of the top "half" of the barrel.

 

[Onoff]

3 IBC tanks in a row.

 

[Bladevane]

It's only sealed between top-ups to contain heat. Oxygen will enter as soon as the lid is removed. My belief is that it will still be aerobic, but quicker than a conventional compost bin or heap as heat is retained and the waste product is mixed up. As I said, Let's see how it goes.

 

[julianf]

It's only sealed between top-ups to contain heat. Oxygen will enter as soon as the lid is removed. My belief is that it will still be aerobic, but quicker than a conventional compost bin or heap as heat is retained and the waste product is mixed up. As I said, Let's see how it goes.

Sure, my prototyping will be a lot easier if it's done remotely (through you! ; )


I reckon another option would be some sort of stack system with air forced through. I'm thinking size and space efficiency more than anything else.

Our garden is small so I'm talking a bit of grass from the mower now and again and food waste. 3 ibcs are well out of my league!

 

[Mr Fro]

Good use for an old hot water cylinder!

 

[julianf]

I'd imagine the fluid to be somewhat corrosive, even to copper.

Don't copper compounds kill bacteria?

I mean all these things are relative. Maybe a modern stainless one would be better?

 

[Mr Fro]

I'd imagine the fluid to be somewhat corrosive, even to copper.

Don't copper compounds kill bacteria?

I mean all these things are relative. Maybe a modern stainless one would be better?

That's a very good point!

 

[Onoff]

Our garden is small so I'm talking a bit of grass from the mower now and again and food waste. 3 ibcs are well out of my league

50/50 green waste to "brown" if going for biogas. Animal dung, horse / cow has the requisite methane making bacteria. High sugar waste, apples etc are good too. Watching a US guy the other day.

 

[gaz1]

barrel sieve same thing

you can use bicycle parts to turn it

 

[8ob]

 

[gaz1]

since im looking at the biogas side of it and found something and naturally thought of this thread post

it uses 3 ibc tanks but actually only uses one of them as the food waster the other 2 are to create a gas which i think you might find a use for

what its doing is this