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Double Bell Heater Construction
and Testing Workshop

with Alex Chernov  and Norbert Senf

Caledon, Ontario
October 23 - 25, 2009

Feedback, Discussion, and Results

Bell and Combustion Workshop
The workshop took place at Alex Chernov's house.
Alex kicked it off on Friday morning with a classroom session describing the test heater we would build.
It incorporates a number of features allowing changes to the firebox air systems and gas path in the heat exchange section.

Bell and Combustion Workshop
Cross section.
section
CAD model.

Bell and Combustion Workshop
The new heater testing lab directly behind the house is well insulated and will eventually become a sauna.
With a busy work and family life, it will make it easier for Alex to conduct automated testing.
It will become part of the Lopez Labs Co-operative.
Weather on the first day was cold, rainy and windy.
Colin Coveny operates the brick saw, under a tent.


Bell and Combustion Workshop
Alex's new design for a pizza oven sits covered in plastic to the right.


Bell and Combustion Workshop
View of the main house. The lab is at the rear.

Bell and Combustion Workshop
The workshop was limited to 12 people and sold out early. Attendees came from as far away as Washingon state.
After expenses, the workshop raised a total of $2540.00 for MHA.

Bell and Combustion Workshop
Layout.

Bell and Combustion Workshop
Paul Anderson contemplates the layout as Chris Springer and Alex get the bottom end started.

Bell and Combustion Workshop
Firebox floor support and air channel (top)
Heat exchange section (bottom)

Bell and Combustion Workshop
At the lower right corner, two inlets into the vertical duct that will connect to the upper bell.

Bell and Combustion Workshop
Right rear wall: the open slot is to allow for an adjustable firebrick baffle. This will allow testing of different bell configurations.

Bell and Combustion Workshop
Detail of the front grate support ledges.

Bell and Combustion Workshop


Bell and Combustion Workshop
Lineup at the brick saw.
Carsten Homstead does some freehand grinding.

Bell and Combustion Workshop
Sidewall air system.
Alex has recently changed his air system and no longer uses sidewall air in his production heaters.
Now, there is a small transverse grate at the rear, and a larger one in the front.
The test heater has sidewall air for testing. The holes can be closed off with ceramic fiber plugs to allow different configurations.
At the far right (with the hand on the brick) is a stacked joint, to allow for changing the size of the updraft channel for testing.

Bell and Combustion Workshop
Firebox lintel slab.

Bell and Combustion Workshop


Bell and Combustion Workshop
The tall stack of single firebricks at the top right is extra mass and heat exchange surface in the lower
bell, and is not creating any channels.
Note the vertical slot at the right rear of the firebox. This is a feature of the Kuznetsov design and is
intended to balance the pressure between the firebox and the lower bell.

Bell and Combustion Workshop
Richard Porter

Bell and Combustion Workshop
Mathew Froud, Carsen Homstead and Jerry Frisch

Bell and Combustion Workshop

Bell and Combustion Workshop

Bell and Combustion Workshop
Creating support for the bake oven floor slab.

Bell and Combustion Workshop
Hands on learning.

Bell and Combustion Workshop

Bell and Combustion Workshop
Firebox exit slot into the bakeoven.
It is a black oven with a "carburetor" based on Lars Helbro's design.

Bell and Combustion Workshop
Course by course drawings are tacked up on the walls.
Chris Springer confers with Tristan Lebreton.

Bell and Combustion Workshop

Bell and Combustion Workshop

Bell and Combustion Workshop
The Redart clay mud covers a ceramic paper expansion strip, to allow for vertical firebox expansion below the oven.
Bake oven door opening is in place at the front.

Bell and Combustion Workshop

Bell and Combustion Workshop

Bell and Combustion Workshop
Doug Mayer, Richard Porter and Jim Frisch.

Bell and Combustion Workshop
Ready for the lower bell capping slabs.

Bell and Combustion Workshop
Upper bell.
Checking the plumb to the chimney connection.

Bell and Combustion Workshop

Bell and Combustion Workshop
Slot on the right is for a bypass damper.

Bell and Combustion Workshop
Joel Dick precuts the concrete block facing.

Bell and Combustion Workshop
Dry layout of front facing. Half the heater was faced in concrete solid 4" blocks, half in clay bricks, to allow comparison of heat transfer.

Bell and Combustion Workshop
The block facing was laid up in fast thinset, which sets up in half an hour.
Note the tight joints.
The brick facing is laid up in Redart/sand mortar.
The stacked joint in the brick facing covers a similar stacked joint in the core.
This will allow reconfiguration of the updraft channel that connects the two bells.

Bell and Combustion Workshop
One way to do a cleanout opening. The firebrick plug is set in clay/sand mortar.

Bell and Combustion Workshop
Installing the Pisla 501 firebox door.

Bell and Combustion Workshop
Lighting the curing fire.

Bell and Combustion Workshop
Everything was cold and wet, making the fire slow to start.
It took a few extra minutes to get going, but drafted immediately and started clean, with minimal smoke from the chimney.

Bell and Combustion Workshop

Bell and Combustion Workshop
Burning well after 10 minutes.

Bell and Combustion Workshop
Air intake is through the ashbox door, which is left wide open.


While the heater was warming up with the first fire, we looked at some previous testing results from Lopez Labs.
including a Web page of example burns demonstrating various conditions.

Bell and Combustion Workshop
Demonstrating the Testo 330-2 flue gas analyzer.

October 27/09: Discussion with Lars Helbro about measuring particulates with the Condar method

This was the second classroom session on the testing component.
The first session was on theory.

Bell and Combustion Workshop
Alex's mother-in-law cooked fabulous Russian lunches for all three days.

Bell and Combustion Workshop
After construction cleanup, setting up the testing gear.

Bell and Combustion Workshop
Pressure tap into the chimney for the Condar portable dilution tunnel

Bell and Combustion Workshop
Recording fuel load data.

Bell and Combustion Workshop
Each piece is weighed individually. A moisture reading was taken from 3 pieces on a split face and averaged.

Bell and Combustion Workshop
Fuel load. Pieces are numbered 1 - 11, from right to left.

Bell and Combustion Workshop
Fuel load stacked in heater, ready for the test.
The firebox was quite warm, and the wood was at 14% moisture.
Kindling from the side, with top ignition.

Bell and Combustion Workshop


Bell and Combustion Workshop
Vacuum hose to the Condar.

Bell and Combustion Workshop
Just after ignition. The fire started fast, because of the warm firebox and dry wood.

Bell and Combustion Workshop
Nice staged start.

Bell and Combustion Workshop
Flames visible through oven door.

Workshop Participants:

1) Steve Bushway
2) Joel Dick
3) Tristan Lebreton
4) Colin Coveny
5) Carsten Homstead
6) Chris Springer
7) Paul Anderson
8) Doug Mayer
9) Jerry Frisch
10) Jim Frisch
11) Mathew Froud
12) Richard Porter

Instructors:

Alex Chernov
Norbert Senf

Bell and Combustion Workshop

Check back for test results.
Initial indications were of an excellent burn:
- almost no smoke at startup
- low CO, low oxygen, low stack temperature, high efficiency.

October 27/09: Discussion with Lars Helbro about measuring particulates with the Condar method

October 28/09: Workshop Feedback from Chris Springer

Nov 1/09: Preliminary Test Results from Alex Chernov

Nov 1/09: Technical Discussion with Dave Misiuk on Efficiency Definition and 95% Oxygen Recovery



This page was updated on March 29, 2010
This page was created on October 26, 2009