Probably the hardest task, when making a gasifier, is the blowing/suction fan. Thanks to the famous Gingery engineering family there is help at hand. How to Design & Build Centrifugal Fans for the Home Shop is packed with everything you need to know about constructing the right fan for the task at hand.
There are five chapters; fundamentals, design, construction, testing & measurement and applications.
After experimenting with various fans, that were woefully underpowered, I am sure this new book acquisition will help me to build the right fan. The applications chapter even has details on building a cyclone separator, ideal for cleaning ash out of your wood gas.
The book can be bought from Amazon - How to Design and Build Centrifugal Fans