We’ve received a substantial amount of emails since we posted last, thank you everyone. We will be sure to email you back as soon as the plans are ready for release. For now though, read here to get your appetite wet, this is also the page where they’ll become available when we release them.

We just wanted to let everyone know that we’re hard at work, working on plans so you can build your very own wood burning vehicle! The plans will be available for purchase soon. We will let you all know when they’re ready. In the mean time, if you know you’ll be interested, shoot us an email and we’ll keep you up to date. BeaverEnergy@gmail[dot]com.

So it is time to size a gasifier for that old Delorean sitting in the backyard. What you don’t want to do is make it to big! This will cause excessive motor damaging tar caused by insignificant tar destructing high temperature do to the low flow rate. To small lends to excessive pressure drop, weak gas, super heated parts and gasifier melt down. So getting this right lends to continuous motion of the old internal combustion motor. So with out getting in to the science behind the wheel (if you want to know you can post a question) lets look at whats necessary to know. First what is the horse power of your motor at cruising speed? Well to figure that use this table to calculate the CSHP cruising speed horse power.

CSHP Table

Fuel Economy (mpg)      Fuel Use Rate (gph)           Engine Output (hp)

5.5                                                10.0                                     100
11.0                                                5.0                                        50
22.0                                               2.5                                         25
55.0                                               1.0                                         10

Now with this it is possible to calculate wood consumption rates knowing that typically gasifiers require 22lb of wood to replace one gallon of fuel. So taking this and doing the math based on a maximum hearth load per square inch of gasifier size(other science behind the wheel) we come to the sizing table below.

Horse Power              Wood  (lb/h)         Fuel (Btu/h)            Gasifier Size (in)

        100                          200                   1400                       16.0
           50                          100                      700                       11.4
           25                             50                      350                        8.0
           10                              20                     140                         5.1
             5                               10                        70                        3.6

Now that we have the basic knowledge to size our gasifier next week we can start looking at the important factors in constructing a stratified down draft gasifier.

Lets get started. There are several basic gasifier types fixed bed sometimes referred to as moving bed, updraft, fluidized bed, suspended particle and downdraft. We have built and tested many types and variations of most of the above and have chosen to use a variation of the downdraft system know as the stratified downdraft gasifier. This was chosen for the easy of construction, reliability of operation and the quality of gas. We will be showing the construction of the stratified gasifier in depth over the coming months including sizing and operation. The basic concept uses an open top cylindrical vessel in which the biomass and air may pass uniformly downward self regulating reaction. The following schematic shows the different layers or strata of the stratified downdraft gasifier.

———————–
Biomass fuel (wood pellets)
———————–
Flaming Pyrolysis
———————–
Char Reduction
———————–
Inert Char
———————– Grate

Gas and Char

Well with out getting bogged down in the details that’s pretty much all you would need to know for now. However if you have any questions please post a comment and I will get you the details. Next time I will be looking at how to size the gasifier for your motor “Superficial Velocity” 101.