Category Archives: Test Oven

All the posts concerning the small Test Oven.

Watt meter

How to measure reliable the amount of electricity that’s being used by the demonstration pyrolysis cell? With a couple of KW infra-red heaters not so simple especially when you want to integrate the measurements in the computerlog of the test. To test the concept I took an old transformer, replaced the old secondary winding by two windings of the 230 volt wire. Curious if I get a good potential difference on the old primary winding. The primary winding is been shorted with a 20 Ohm resistor. And the voltage over the resistor can be converted in a digital value and fed into the control computer.

Old trafo
Current trafo
Current trafo


principle of operation Source wikimedia


Care must be taken that the secondary of a current transformer is not disconnected from its load while current is flowing in the primary, as the transformer secondary will attempt to continue driving current across the effectively infinite impedance up to its core saturation voltage. This may produce a high voltage across the open secondary into the range of several kilovolts, causing arcing, compromising operator and equipment safety, or permanently affect the accuracy of the transformer. source wikipedia

The practice is more complicated due to the load so the real RMS need to be calculated. A acs712 chip connected to an Arduino measures every cycle during one second the actual wattage that is being consumed.

asc712 module
asc712 module
All the pieces of the control software are slowly taking shape
All the pieces of the control software are slowly taking shape
Posted in demonstration furnace, pyrolysis test, Test Oven | Comments Off on Watt meter

Triac Block

TRIAC BLOCK a solid-state relay with I2C interface.

Looking for parts for our demonstration pyrolysis furnace I came across this design. Capable to regulate the 1Kw Elstein infrared heater without much effort. Controllable trough the I2C bus it connects simple to the computer that controls the furnace. Trough the link I contacted the designer and he did have spare assembled PCB’s, a deal was made and a problem solved.

From time to time I get requests to make some high power switching, so I decided to design a solid-state relay that could handle a lot of different situations. The most common use for it I have is refurbishing old ceramic kilns. Since our technical life is close to the stage (both theatre and music), I also wanted it to be usable as a dimmer module. And, just for kicks, as a single phase AC motor speed controller, in case we would want that.
So here it goes. The design and code are on github:
Elstein ceramic heater
1KW Elstein infrared heater, four of them will provide the energy that is needed for the pyrolysis process.
Posted in demonstration furnace, pyrolysis test, Test Oven | Comments Off on Triac Block

Manual heliostat

The first steps towards the manual heliostat. A couple of square meters for test purposes must be doable by hand. East west the mirrors can simple pivot around their base and up and down is accomplished by a screw-thread.

The back reflector
backside manual heliostats
backside manual heliostats
Little 30 x 30 cm tile mirrors
near the focus

With 6 mirrors the open test cell reached already 80 degrees Celsius. With the back reflector the temperature went over the 100 degrees Celsius.

Posted in Mechanical Heliostat, Solar Energy, Test Oven | Comments Off on Manual heliostat


From the Dutch importer of Elstein we got ten 1000 Watt modules to experiment with. They will form the heart of our first demonstration furnace. Elstein ceramic heater
After the ‘Proof of Principle’ and the ‘Proof of Practice’ it’s time to make a professional furnace that can be shown to the public.bleuprint

Posted in pyrolysis test, Test Oven | Comments Off on Elstein

Pyrolyzed test-rabbit

The test went successful.

Only carbon remains and the carbonized bones of course, the bones are very brittle.

pyrolyzed test rabbit

The highest temperature reached was 380 degrees Celsius. Ideally a higher temperature is better, the definitive pyrolysiscells must reach 500 to 600 degrees Celsius to produce as little unwanted side products as possible.

Start weight rabbit 1043 gram, the tray weights 840 gram, total weight 1883 gram.
After 15 hours on 80 degrees Celsius  1438 gram, 445 gram evaporation
The end result 1017 gram, 421 gram less then after the evaporation phase
So there remains 177 gram carbon and bones or 177/(1043/100) = 16,97%.

Posted in pyrolysis test, Test Oven | Comments Off on Pyrolyzed test-rabbit

Test Rabbit

Infrared test

Stripped and prepared microwave

A broken microwave oven is the base stripped the useless parts out and closed all the holes in the oven. Made three vents pressure inlet and outlet and the outlet for gases during the pyrolysis phase.


All the newly created spaces filled up with extra insulation.

infrared test

Getting a small animal to preform tests on, isn’t that simple.
The supermarket had a test rabbit nearing his ultimate sell date with 30% deduction.


And the test is underway.
Temperature set to 80 degrees with thermocouple in carcass.
Curious to see how far the evaporation of the water-content has progressed after 24 hours.

Posted in pet cremation, pyrolysis test, Test Oven | Comments Off on Test Rabbit

Rattus carbonized

A rat experiment.

184 gram rat

A dead rat in the garden, 184 gram, big enough to fill the little pyrolysiscell.

rat cell
Rat in the pyrolysis cell 3319 gram

A bit pushing was necessary to get the rat in the cell.

Water vapor escapes

Brute force approach today heating up vaporizing the water content and pyrolysis phase direct afterwards.

hydro acro
Burning hydrogen and acrolein from the rat

Shortly flammable gases start to come out of the exhaust, mostly hydrogen gas and acrolein from decomposing fat.

carbon remains left the head is still recognizable

It is clear that animals remains don’t give nice pieces of biochar. The flesh melts when the cell membranes losing their integrity. On the left side is the skull of the rat with the front teeth is visible, the bones are very brittle. Only 24 gram remains 13% from the original 184 gram.

Posted in Carbon data, Test Oven | Comments Off on Rattus carbonized

First fire

First fire in the big outside pyrolysis furnace. The old converted propane tank is filled with pine bark. The fire is maintained with pinecones  pine needles and  little twigs.

pyro first fire

Loaded with the pyrolysiscell full of pinebark the first fire in the bigger pyrolysis furnance


Hydrogen flame
In the right upperside a hydrogen flame shoots downwards from the exhaust
Posted in Test Oven | Comments Off on First fire