Abstract: An elevator rescue system includes a power source of back-up electrical power. A manually-operated, rescue enable switch switchably permits the transmission of electrical power from the power source to a motor brake coil of an elevator car during a rescue operation such that the energized coil releases the motor brake to move the car to a desired landing. A speed detector measures the speed of the elevator car and thereupon generates a speed control signal corresponding to the speed of the car. An overspeed detection circuit has a first input for being actuated when receiving electrical power from the power source, a second input for receiving the speed control signal, and an output for transmitting electrical power to the motor brake coil when the speed control signal is below a predetermined value and for automatically stopping the transmission of electrical power when the speed control signal becomes higher than a predetermined value. A manually-operated brake release switch has an input and an output.

Abstract: An elevator rescue system includes a power source of back-up electrical power. A manually-operated, rescue enable switch switchably permits the transmission of electrical power from the power source to a motor brake coil of an elevator car during a rescue operation such that the energized coil releases the motor brake to move the car to a desired landing. A speed detector measures the speed of the elevator car and thereupon generates a speed control signal corresponding to the speed of the car. An overspeed detection circuit has a first input for being actuated when receiving electrical power from the power source, a second input for receiving the speed control signal, and an output for transmitting electrical power to the motor brake coil when the speed control signal is below a predetermined value and for automatically stopping the transmission of electrical power when the speed control signal becomes higher than a predetermined value. A manually-operated brake release switch has an input and an output.

Abstract: A furnace of a pulverized coal firing boiler includes a coutant bottom and walls intersecting with the coutant bottom and extending generally vertically therefrom to enclose and define an interior combustion chamber. A first windbox disposed in a corner of the combustion chamber includes therein a vertical array of consecutively spaced coal compartments. A coal nozzle of the lowermost coal compartment of the vertical array is disposed at least ten feet from the intersection of the walls with the coutant bottom. A second coal nozzle is disposed within a second adjacent coal compartment at a first vertical spacing to the first coal nozzle; a third coal nozzle is disposed within a third adjacent coal compartment at a second vertical spacing to the second coal nozzle; and a fourth coal nozzle is disposed within a fourth adjacent coal compartment at a third vertical spacing to the second coal nozzle.