This type of feeders is built with the system of two screw-conveyors, one charging in diagonal from the tank the material into the second one (horizontal), which convoys the solid fuel into the combustion chamber. These feeders are suitable for sawdust, wood-chips (small and big), pellets or wood-waste. The cubic hopper is fitted with a mechanical stirrer which avoids the creation of fuel caps, remixing the stored material continuously. This feeding system has, by the fact that the lower screw-conveyor is always emptying itself, a structural stop for the fire; it is impossible for the flames to return into the feeder. The CAR-SM feeders are an excellent solution for all kinds of materials, provided painted and assembled and can be applied from the 30th model on.