Abstract: A gate-type feeder control system has level and weight sensors for monitoring the output of the system to a conveyor or other receiver, an electronic control circuit responsive to the sensors, and a hydraulic actuator circuit including a plurality of valves to provide the desired output of a feeder gate. In the electronic circuit, a master set point signal is entered and compared with the output signal from the sensors. The output flow to the receiver of the system is continuously adjusted by a deviation controller to reduce the deviation in these two signals. Erratic changes in system output are avoided by a deadband circuit introduced into the electronic circuitry to buffer excessive oscillation, overresponse and even instability caused by transient size change and lumping associated with bulk materials. The electronic circuit also includes an averaging module to average the level/weight of the material being discharged to obviate responding to peak levels.

Abstract: A system and method of delivering dried fine fuel. Moist coal is extracted from a source and initially dried to a moisture content of five percent by a gas fired dryer plant. The initially dried fuel is then transported to a central processing site whereat the coal is pulverized and further dried and fed to a storage silo. Tractor-trailers receive the dried fine coal from the storage silo and transport same to the end user's site. The trailer is disconnected from the tractor and is utilized as a storage tank as the coal is withdrawn therefrom on an as-needed basis. A fuel injector coupled to a variable rate feeder is utilized in one embodiment to convey the dried fine fuel from the trailer to the burner.

Abstract: A method of drying wet coal fines smaller than 28 mesh in size employs both a vibrating fluidized bed type dryer and a coal fired burner for supplying hot drying gases to the dryer. A regenerative separator is interposed between the coal fired burner and the fluidized bed type dryer to satisfactorily remove particle matter from the gases without unacceptable pressure losses. Hot gases exhausted from the fluidized bed type dryer are also cleansed to remove particulate coal particles which are used as fuel for the coal fired burner.