Abstract: A fuel system (10) for a gas turbine engine (18) having a shaft (30) and requiring fuel to be supplied at a first rate for engine start up, the fuel system (10) including: a main fuel pump (14) for providing fuel to the gas turbine engine (18), the main fuel pump (14) having an output varying with shaft speed, the output being at a windmilling rate when the engine (18) is windmilling, the windmilling rate being less than the first rate; and an auxiliary fuel pump (40) for providing fuel to the gas turbine engine (18) and having an auxiliary output rate greater than or equal to the difference between the first rate and the windmilling rate. A method of operating such a fuel system (10) is also disclosed.

Abstract: A fuel control valve (100) includes a rotary throttling valve assembly (4,7) providing one or more of the benefits of being lightweight, having a relatively low power consumption, having a fail-closed structure and/or zero leakage. The fuel control valve (100) is a rotary, throttling valve that is actuated via a rotary torque motor (70). The valve (7) can be spring loaded for providing positive shutoff. Position indication of the valve (7) is obtained via a position sensor (31) and cam (13) mounted to the throttling valve shaft at a driven end (98). In a de-energized state, a torsion spring (45) is provided that is loaded to rotate the valve (7) to the closed position. The fuel control valve (100) may be advantageously utilized in extreme operating environments, e.g., such as extreme temperature and vibration environments found in missile control fuel systems.

Abstract: A fuel control system (10) in a turbine engine includes a centrifugal boost pump (20) that receives fuel from a fuel tank and increases the pressure of the fuel. A piston pump (40) boosts the fuel pressure to levels required by the turbine engine and meters an amount of fuel delivered to the turbine engine. A speed controlled electric motor (30) drives the piston pump (40). The electric motor (30) is driven by an electronic speed control wherein by controlling motor speed, fuel flow to the turbine engine is controlled, and fuel flow is directly proportional to the speed of the motor (30). Accordingly, the system (10) seeks precision of fuel control that can be achieved with an accuracy of better than +/?3% over a 30:1 fuel flow range.

Abstract: A system for injecting noise signals onto power generated by a power source comprising: a voltage source; a device under test having a power input in operable communication with the noise introduction apparatus; and a noise introduction apparatus interposed between the power source and device under test in operable communication with the voltage source, the noise introduction apparatus comprising, a switching device configured to provide a low impedance conductive path when commanded, and a current limiting device in series with the switching device, the current limiting device configured to provide a low impedance conductivity for a selected current and a selected duration. The switching device and current limiting device cooperate to shunt the voltage source to the power input.

Abstract: A fuel control valve (100) includes a rotary throttling valve assembly (4,7) providing one or more of the benefits of being lightweight, having a relatively low power consumption, having a fail-closed structure and/or zero leakage. The fuel control valve (100) is a rotary, throttling valve that is actuated via a rotary torque motor (70). The valve (7) can be spring loaded for providing positive shutoff. Position indication of the valve (7) is obtained via a position sensor (31) and cam (13) mounted to the throttling valve shaft at a driven end (98). In a de-energized state, a torsion spring (45) is provided that is loaded to rotate the valve (7) to the closed position. The fuel control valve (100) may be advantageously utilized in extreme operating environments, e.g., such as extreme temperature and vibration environments found in missile control fuel systems.

Abstract: A fuel control system (10) in a turbine engine includes a centrifugal boost pump (20) that receives fuel from a fuel tank and increases the pressure of the fuel. A piston pump (40) boosts the fuel pressure to levels required by the turbine engine and meters an amount of fuel delivered to the turbine engine. A speed controlled electric motor (30) drives the piston pump (40). The electric motor (30) is driven by an electronic speed control wherein by controlling motor speed, fuel flow to the turbine engine is controlled, and fuel flow is directly proportional to the speed of the motor (30). Accordingly, the system (10) seeks precision of fuel control that can be achieved with an accuracy of better than +/?3% over a 30:1 fuel flow range.

Abstract: A pulper for pulping a fiber suspension includes a vessel, an extraction plate assembly and a rotor. The extraction plate assembly is disposed within the vessel and includes a metal plate with a plurality of holes extending therethrough. A plurality of metal inserts are respectively disposed within the holes and project from the plate. Each insert is removably attached to the plate. A rotor is disposed within the vessel adjacent to the extraction plate assembly. The inserts are removably attached to the plate by brazing the inserts within the holes, or slightly shrinking the inserts using liquid nitrogen and placing the inserts in the holes.

Abstract: An apparatus for continuously loading fibers in a fiber suspension with a chemical compound includes a deflocculating vessel having an interior chamber, a fluid inlet connected with the interior chamber, a fluid outlet connected with the interior chamber, and a high shear imparting device disposed within the interior chamber for imparting high shear forces to and thereby deflocculating the fiber suspension. A mixing container has an interior compartment, a fluid inlet connected with both the interior compartment and the fluid outlet of the deflocculating vessel, a fluid outlet connected with the interior compartment, and a low shear imparting device within the interior compartment for imparting low shear forces to the fiber suspension. A gas supply is connected with the interior chamber of the deflocculating vessel and/or the interior compartment of the mixing container. The gas supply is configured for supplying a gas to and pressurizing each of the deflocculating vessel and the mixing container.

Abstract: An apparatus for continuously loading fibers in a fiber suspension with a chemical compound includes a deflocculating vessel having an interior chamber, a fluid inlet connected with the interior chamber, a fluid outlet connected with the interior chamber, and a high shear imparting device disposed within the interior chamber for imparting high shear forces to and thereby deflocculating the fiber suspension. A mixing container has an interior compartment, a fluid inlet connected with both the interior compartment and the fluid outlet of the deflocculating vessel, a fluid outlet connected with the interior compartment, and a low shear imparting device within the interior compartment for imparting low shear forces to the fiber suspension. A gas supply is connected with the interior chamber of the deflocculating vessel and/or the interior compartment of the mixing container. The gas supply is configured for supplying a gas to and pressurizing each of the deflocculating vessel and the mixing container.

Abstract: A pulper for pulping a fiber suspension includes a vessel, an extraction plate assembly and a rotor. The extraction plate assembly is disposed within the vessel and includes a metal plate with a plurality of holes extending therethrough. A plurality of metal inserts are respectively disposed within the holes and project from the plate. Each insert is removably attached to the plate. A rotor is disposed within the vessel adjacent to the extraction plate assembly. The inserts are removably attached to the plate by brazing the inserts within the holes, or slightly shrinking the inserts using liquid nitrogen and placing the inserts in the holes.

Abstract: A pulper for pulping a fiber suspension includes a vessel, an extraction plate assembly and a rotor. The extraction plate assembly is disposed within the vessel and includes a metal plate with a plurality of holes extending therethrough. A plurality of metal inserts are respectively disposed within the holes and project from the plate. Each insert is removably attached to the plate. A rotor is disposed within the vessel adjacent to the extraction plate assembly. The inserts are removably attached to the plate by brazing the inserts within the holes, or slightly shrinking the inserts using liquid nitrogen and placing the inserts in the holes.

Abstract: An apparatus providing process water used for making or processing a fiber suspension includes a multi-compartment tank with a top, a bottom wall, and a plurality of exterior sidewalls. Each compartment has an inlet positioned near the top, an outlet positioned near the bottom wall, and at least one intervening wall common with an adjacent compartment. Each intervening wall has a height defining an overflow weir whereby the compartments are arranged with sequentially decreasing maximum fluid levels. Each intervening wall also has a backflow device positioned near the bottom wall. The backflow device is selectively openable to allow flow from one compartment to an adjacent compartment in a direction opposite to a flow direction over the corresponding overflow weir.

Abstract: A temperature measuring circuit which includes a primary temperature sensor such as a thermocouple, an external source for generating predetermined temperature modifying signals, and a signal combining circuit for combining the modifying signals with the temperature sensor signal to generate a modified output signal and display thereof.