activated carbon production technology

There are 5 types of activation furnace in the world: American Multi-stage rake furnace, French SLEP furnace(the foregoing vertical I), British STK furnace(the foregoing vertical II), Japonic converter and our type. Our furnace can be considered to the best advanced type. It is base of British STK furnace(vertiacl II), borrows the excellence point of SLEP furnace(vertical I), is elaborate improvement. This type of furnace has the following strongpoints after actual operating in Indonesia. 1. do not need any additional fuel, do not need lots of gas like rake furnace and converter. 2. lower eneger cost, it costs 4.8MT water steam for every 1 MT finished activated carbon. But compare with others, rake furnace cost 17.6MT, converter cost 12.4MT water steam. 3. less investment. As the same capacity of activation furnace, suppose the investment of our type is 100%, then the STK type is the same cost, but the converter costs 168%, the SLEP type costs 200%, and the rake type costs 720%.