• If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • Finally, you can manage your Google Docs, uploads, and email attachments (plus Dropbox and Slack files) in one convenient place. Claim a free account, and in less than 2 minutes, Dokkio (from the makers of PBworks) can automatically organize your content for you.


BEK Assembly Instructions v1-9

Page history last edited by jay 10 years ago




The step-by-step instructions below will guide you to turn your mysterious pile of plumbing and fabricated parts into a biochar making machine which will allow you to visit all of the curious production variables that are important in the creation and application of biochar. After you have assembled the BEK (Biochar Experimenters Kit, v1.x), visit the BEK Operation Manual for run instructions.


Table of Contents:

I) Introduction

II) Tools Needed for Assembly

III) Assembly Instructions

1. Body

a) Biochar Boot

b) Reactor Legs

c) PyroBox

d) Sweep Gas Valve

e) Reactor Insulation

2. Chimney

3. Burner 

a) Burner Body

b) Burner Puff Lid

c) Propane Connection

4. Install Ignitors

a) Chimney

b) PyroBox

5. Gas Cap

6. Ejector and Gas Lines

a) Bio-Oil Condensing Circuit

b) Non-Condensing Circuit

7. Reactor Lid: Feedstock Auger and Level Switch

8. Hopper

9. Biochar Auger and Reservoir

10. Instrumentation


I) Introduction

The BEK 1.9 had a few significant changes in its design to improve its material handing capability as well as increase the ease of manufacturing and assembly of the unit as a whole.

The Biochar Boot is now a more of a rounded square design that greatly improves the mobility of biochar through the auger. This along with an added stir bar greatly improves the flow of the feedstock and biochar through the reactor itself. A hanger bearing was included in this round to enhance auger reliability across run conditions, and the sweep gas valve has been reconsidered mainly for ease of assembly. With these changes the legs have been moved to now attach to the main reactor body be able to offer inspection of the Biochar Boot without disassembling the rest of the unit.


II) Tools Needed for Assembly

    • 1/2'' wrench
    • 9/16'' wrench
    • scissors
    • philips head screwdriver
    • flat head screwdriver 
    • pipe wrench 
    • 3/8ths drill   
    • 9/64ths hex wrench


III) Assembly Instructions


1. Body

A) Biochar Boot




  • Start with the main reactor body.
  • The Biochar Boot attaches to the bottom of the main reactor body, flip the reactor body upside down to access the weld nuts on the bottom of the reactor. 
  • Note on orientation: The bottom of the reactor will be the flange nearest to the square stock-like leg attachments on the reactor body. Flip the reactor body so these are facing upwards to access the bottom of the reactor.
  • Use the fiberglass tape around the flange of the Biochar Boot. Ream the bolt holes out so that it will be easier to pass the bolts through the fiberglass tape. It is easiest with a drill bit.
  • Apply the high temp mortar onto the fiberglass tape to ensure a gas tight seal. 
  • Note on orientation: While the reactor is upside down, face the two square openings on the main body. Notice the Biochar Boot is larger at one end and tapers down. Place the larger end of the Biochar Boot to the right at a 90 degree angle to the square ports on the reactor.
  • Attach the Biochar Boot with 5/16ths bolts. 


B) Reactor Legs

  • Locate the four pairs extending threads on the char bucket.
  • Attach the four legs of the reactor using the provided 9/16ths nuts.
  • There are two pairs of legs each mirror images of each other. Ideally arrange them so that the feet are arranged to evenly distribute the weight. 


C) PyroBox

  • Flip the reactor onto its feet.
  • Apply fiberglass tape and mortar to the bottom square flange on the main reactor.
  • The PyroBox is the large square component with the protruding handle. 
  • Orient the PyroBox with the handle out to the right of the reactor and the smaller circular port facing downward. (orientation notes valid when looking on to the square ports, with the reactor right side up on its feet).
  • Attach the PyroBox onto the reactor body with 5/16ths bolts.  


D) Sweep Gas valve

  • The sweep gas valve has the long handle with the square flange attachemnt. 
  • After applying high temp mortar, attach the square flange to the bottom of the PyroBox with the handle extending toward the right of the reactor, in the same direction as the handle on the PyroBox itself.




  • Thread the milled 1.5'' halved coupler into the sweep gas port on the Biochar Boot. When looking on to the Biochar Boot, this will be the 1.5'' threaded port on the right side of the Biochar Boot.
  • Use high temp mortar and coat this milled 1.5'' halved coupler and the termination on the sweep gas valve. 
  • Slide the short (~1.5 ft) flex line over the two terminations, and secure with two hose clamps.  


E) Reactor Insulation

  • Unroll the white insulation material. Wrap the body of the main body of the BEK reactor with the insulation material. Make sure to cut out holes in the insualtion for all of the instrumentation ports and gas flow ports on the reactor to retain access to these ports.
  • Fit the stainless steal jacket around the body of the main BEK reactor. Be sure to line up the ports in the suggested cut-outs.
  • Tighten the stainless steel jacket around the reactor by using a flat head screw driver on the attached hose clamping mechanism. 


2. Chimney

  • Place a strip of fiber glass tape onto the round flange of the chimney and punch out the holes so the bolts will pass through. Apply some high temp mortar onto the fiberglass tape.  
  • Match the appropriate flanges of the Chimney to the PyroBox and the top retort port on the main reactor body.  
  • Tighten with 3/4 x 5/16'' bolts.




  • Find the 6 hole flange with a round extending lip, this will bolt onto the PyroBox as the adapter for the flex chimney connection.
  • Obtain the chinmey connecting flex tube. This will fit over the flange adapter and mate with the chimney above. Use the two hose clamps to secure the flex tube in place. 


  • Roll the stove pipe extension into its cylindrical form.
  • When fitting the stove pipe extension onto the BEK Chimney, you may want to fold in the top of the Chimney with a hammer.
  • Use t he self tapping screws to hold the chimney extension into place. 


3. Burner

A) Burner Body

  • Add the fiber glass tape and the high temp mortar to the burner flange in the same manner as the previous steps.   
  • The lighting port cap is extended with a 1/2'' x 7'' pipe nipple to keep in cooler temperatures. 
  • Note: A burner extension comes with the BEK. Use the burner extension between the burner and the burner body if you would like to subject the BEK reactor to lower temperatures.  




B) Burner Puff Lid 

  • For the version 1.2 BEK, attach the poof flap by utilizing three bolts from the chimney flange.
  • Finish the assembly by attaching the poof cover and securing a weight to the end of the lever.




C. Propane Connection

  • Plug the 1/2'' bottom side bung. This will be used to empty any tar collection in the burner during shutdown.
  •  There are two 1/2'' bungs at the top of the burner. Attach the propane connection to the 1/2'' bung closest to the 1.5'' inlet of the burner. The second 1/2'' bung will be used as a lighting and viewing port for the flare. You will want to light this portion of the flare with a second hand held propane torch.
  • Attach an extension of 1/2'' pipe to keep the propane line away from the hot burner. Depending on the location and source of your propane connection this may be different for your set up. You can find propane connections at your local hardware store.
  • Install the brass needle valve in line with the propane line.
  • Connect the propane line after the valve.


4. Install Igniters

  • Strip the wires at the end of the ignitors. Connect the wires to a 12vDC supply (A typical car battery will do).
  • When the ignitors are installed, be sure to keep the wires away from hot surfaces of the BEK. You may want to use some bailing wire to secure them.
  • Note: Avoid contact of High Temp Mortar to the active ignitor element, it will cause the element to burn out.




A) Chimney

  • Drill a 3/8'' hole about two inches from the top of chimney extension.
  • Use the self tapping screws to secure the igniter into place. 





B) PyroBox

  • Drill a hole into the PyroBox directly in front of the burner connection. 
  • Secure the ignitor into place with a screw. 


5. Gas Cap

  • Orientation: The side with the wide flange is the top, from the bottom you will notice that the Gas Cap is double walled. 
  • Place the fiberglass tape and high temp mortar on both the top and bottom flanges of the Gas Cap, punch out the bolt holes to allow for clearance. 
  • Orientation: The square gas out flange will face to the right of the burner/chimney assembly. 
  • Use clay gasketing on the six hole flange. Attach the six hole solid plate to the nearest port toward the chimney.  




6. Ejector, Gas Lines and Description of Circuits

Note:  There are two different orientations that the flex lines can be assembled, please read carefully.


A) Bio-Oil Circuit: Running the BEK in condensing mode will allow the collection of pyrolysis oil. Collection of pyrolysis oil/ Bio-oil may be of interest for experimentation and utilization for various projects. When in condensing mode, any remaining constituents in the gas stream will still be introduced into the burner, ensuring a clean production of biochar and pyrolysis oil. 




  • Attach the cyclone tube plate to the leg of the second 1.5'' plumbing T. The other two ends of the cyclone 1.5'' plumbing T will also be attached to first ejector 1.5'' plumbing T and the 1.5'' brass ball valve.
  • Place the 1.5'' plug into the open end of the ejector plumbing T.
  • Thread on the square gas connectors to the gas line and apply a couple strips of the clay weather stripping to the square flange. 
  • Wrap the flex tube two revolutions, then bolt one square flange to the cyclone, and the other to the gas cap on the top of the main body of the BEK reactor. 




B) Non-Condensing Circuit: Running the BEK in clean mode will take all of the pyrolysis gases from the reactor and burn them in the burner so as not to collect or release any liquids or emissions from the biocharring process. 




  • Assemble the ejector according to the pictures above. The flex line connects to the side of the gas cap with the square flange adapter. 
  • Make sure the three plumbing T's are oriented at a 90 degree angle from each other. 
  • The first picture shows a 1.5'' plumbing plug at the end of the assembly. In Clean Mode, the assembly will differ from the first picture below in that the port populated by 1.5'' plumbing plug will attach to the shorter flex tube. The 1.5'' plug should then be inserted into the leg of the 1.5'' plumbing T (where the 1.5'' close nipple is located according to the first picture below).  


7. Reactor Lid: Feedstock Auger and Level Switch 

A) Auger Bucket

  •  Add some of the clay weather stripping between the mating flanges of the Gas Cap and the Auger Bucket.
  • Use the 5/16'' nuts/bolts to attach them together. 




B) Biomass Auger

  • Use some clay weatherstripping for the flange on the auger port on the far end. 
  • Make sure there is good seals around the hex bolts and the motor bearing. You may need to loosen the auger and add high heat mortar around the edges of the motor. Be careful not to get any of the mortar into the bearings of the motor. 
  • Insert the Auger and Auger Plate and secure with 5/16ths nuts and bolts. 


C) Level Switch

  • The level switch will populate the offset 1.5'' bung in the lid. 
  • There are three paddle sizes included with the fuel level switch. Detach the smaller paddle with a philips screw driver.
  • Thread the 1- 1.5'' plumbing reducer onto the sensor.
  • Attach the longer stainless steel paddle onto the sensor. 




  • Thread the fuel level sensor onto the middle bung of the reactor lid. (The switch can also be added to the 1.5''bung offset slightly from center). The reactor lid is typically attached to the hopper barrel during shipping.
  • Orientation: Make sure the arrow is pointing away from the auger, this is the direction of flow. 
  • Wire the auger to the breaker switch and then to the two wires indicating the Normally Closed (NC) configuration of the fuel level paddle switch. T
  • Use 12v DC: Connect the ground of the auger motor (black) to the negative (-) lead and the common (COM/brown) to the positive (+) lead of a 12v dc source (ie: car battery).




E) Manual Stir Spiral

  • The stir spiral is the long auger-like component with the long bar attached. 
  • Acquire the plumbing for the stir spiral according to the picture below. (1.5-1/2'' reducer bushing, 1/2'' x 2'' plumbing nipple, 1/2''coupler, 1/2-14'' reducer bushing -drilled out, two shaft collars, handle with welded shaft collar).
  • The stir spiral will populate the middle 1.5'' bung in the reactor lid. 
  • Cut an inch or so of fiber glass tape, and pack it into the 1/2'' coupler and add grease into the middle of the coupler with the fiberglass as it is being assembled together. This will ensure an air tight seal while allowing mobility.
  • The two shaft collars will be placed one at the top, visible in the picture, and one at the bottom underneath the 1.5-1/2'' reducer bushing-this latter shaft collar will be added on the bar first and the rest of the plumbing will follow. This first shaft collar will keep the bar from hitting the paddle switch and the second shaft collar on the top will prevent the handle from falling down and disrupting the biochar auger below. Be sure to place the shaft collars so they will keep the stir auger in this range of operation.  


D) Reactor lid

  • The reactor lid will have two 1.5'' bungs and three 1/2'' bungs on the side.
    • These three 1/2'' bungs are for thermocouples, you may use these if you wish.
    • The two 1.5'' bungs are for the level switch and a manual mixer to ensure against bridging. Populate the middle 1.5'' bung with the spiral manual mixer. Populate the second offset 1.5'' bung with the level sensor.   


8. Hopper

  • The monorator ring, shown in the first picture, will slide into the hopper barrel. Use the longer 5/16ths bolts to secure the hopper through the nuts welded to the monorator ring.
  • Assemble the conical hopper insert and slide it into the hopper. This will allow the solid fuel to flow easier through the system. 




  • Use the springs and the wing nuts for the puff lid on the main lid of the hopper barrel.
  • Attach the main lid to the hopper.  


9. Biochar Auger and Biochar Reservoir

A. Biochar Auger Channel

  • Orientation: When standing in front of the burner of the BEK, the Biochar channel will attach to the right cover of the biochar boot.
  • Place fiberglass tape around the bottom flange of the 6 hole flange of the bottom char bucket and add a bit of hight temp mortar around the flange. Bolt the Biochar channel to the bottom using 5/16'' bolts. 
  • Attach the auger channel so that it is angling upwards in its orientation. Attach the second piece of the auger channel. The fabricated T attachment will host the smaller auger motor plate at its end.
  • At the bottom portion of the fabricated T, the char will flow outwards. Here, the biochar bucket will attach using the sewer fitting and no-hub coupler with the two hose clamps. 
  • The auger will slide into the auger channel and bolt to the flange using the 5/16ths bolts. 



B) Biochar Auger

  • Wire the biochar auger motor by connecting the black wire (with the eyelet) of the PWM controller to the green wire on the motor.  The doubled red wire will connect to the red wire on the auger motor. The single stripped red wire will connect to the positive terminal of a 12vDC battery, and the stripped black wire will connect to the negative terminal of the 12vDC battery. 
  • Note: the picture shown is of an earlier version. Note how the wires attach in the photo.  The connector with the two red wires will connect to one of the leads of the auger motor. Black wire with connector will connect to the other lead of the motor. The free end of the red wire will connect to positive and the single black wire (with no connector) will connect to the negative end of a 12v DC supply. (A car battery will work fine in this case).
  • Connect the breaker switch in line with the positive lead of the battery. 
  • Turn the auger on, note the rotation from the other end of the biochar boot. Does its rotation pull the char toward the biochar reservoir from the char boot? If it seems to be pushing char instead of PULLING char, switch the positive and negative leads of the auger wires. 
  • NOTE: please make sure that you are connecting them correctly before adding feedstock/char into the reactor, otherwise the auger will jam and burn out the PWM controller. 
  • After noting the correct direction, place the 6 hole cap on the end of the biochar boot with the circular stock hanger bearing toward the inside of the auger as a support. 




C)  Biochar Reservoir

  • Use fiberglass tape and mortar on either side of the biochar channel.
  • The lid of the char barrel char reservoir will connect to the end of the biochar channel. The 6 hole ring will fit on the inside of the lid to clamp around the char reservoir lid opening to ensure a seal. Be sure to add high temp mortar to this interface.
  • Add the barrel biochar reservoir to the lid. Be sure to support the barrel from underneath.  


9. Instrumentation  

A) Manometer  

  • Connect the manometer face plate to the outside of the square flange on the gas cap. 
  • Install the manometer tube by connecting it to the brass barb on the square flange of the gas cap. Loop the manometer tube around the manometer face plate and secure with zip ties.  




B) Thermocouples

  • Use the appropriate plumbing reducer and compression fitting as ports for the thermocouples.
  • Thermocouple placement is up to the operator, however we like to suggest them into the top of the unit to obtain the temperature of the reactor, the gas out exit port on the Gas Cap, the char reservoir or the two ports located on the retort gas entrance/exit.  





C) Extra ports

  • There are extra ports on the side of the reactor as well as the bottom biochar bucket, reactor lid, and gas cap. These can be used as ports for thermocouples, introduction of various gases for research purposes or water. Plug up all these unused ports with the remaining plumbing fittings so that are no leaks.

Return to BEK Main Page


If you have any questions please contact Jay at jay{at]allpowerlabs{dot}org.



Comments (0)

You don't have permission to comment on this page.