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Mercury-free dissolution of aluminum-clad fuel in nitric acid

Description: It is the purpose of this invention to provide a continuous optimum process for the dissolution of aluminum, without the use of a mercury catalyst. Ile invention generally stated is: a process for dissolution of aluminum comprising: preparing a mixture of nitric acid`and fluoboric acid in a makeup vessel or individual reagents in separate vessels; placing an aluminum element in a dissolver vessel having an overflow; transferring a portion of the mixture of nitric acid and fluoboric acid to the dissolver vessel from the makeup vessel; heating the dissolver vessel and mixture to a boiling temperature and holding that temperature until a desired concentration of dissolved aluminum is achieved; adding a constant flow influent of the mixture of nitric acid and fluoboric acid to the dissolver vessel; and collecting an effluent from the dissolver vessel overflow, said effluent containing a mixture of aluminum nitrate, nitric acid, fluoboric acid, water, and dissolved fuel components. The variables in the above process can be temperature, effluent flow rate, and concentration of the acids as will be discussed later. For corrosion control, it may be necessary to initiate reaction at a decreased HNO{sub 3} concentration and to increase it after a sufficient concentration of aluminum nitrate has accrued. The process may be adapted to batch processing, as well. Again, acid concentrations may be initially relatively small and, then, gradually increased as reaction proceeds until the desired excess of HNO{sub 3} above stoichiometric quantity has been added. Other objects, advantages, and capabilities of the present invention will become more apparent as the description proceeds.
Date: December 31, 1993
Creator: Christian, J.D. & Anderson, P.A.
Partner: UNT Libraries Government Documents Department

A low noise charge ramp electrometer

Description: This invention depicts a electrometer capable of measuring small currents without the use of a feedback resistor which tends to contribute a large noise factor to the measured data. The electrometer eliminates the feedback resistor through the use of a feedback capacitor located across the electrometer amplifier. The signal from the electrometer amplifier is transferred to a electrometer buffer amplifier which serves to transfer the signal to several receptors. If the electrometer amplifier is approaching saturation, the buffer amplifier signals a reset discriminator which energizes a coil whose magnetic field closes a magnetic relay switch which in turn resets or zeros the feedback capacitor. In turn, a reset complete discriminator restarts the measurement process when the electrometer amplifier approaches its initial condition. The buffer amplifier also transmits the voltage signal from the electrometer amplifier to a voltage-to-frequency converter. The signals from the voltage-to-frequency converter are counted over a fixed period of time and the information is relayed to a data processor. The timing and sequencing of the small current measuring system is under the control of a sequence control logic unit.
Date: December 31, 1991
Creator: Morgan, J.P. & Piper, T.C.
Partner: UNT Libraries Government Documents Department

Portable high precision pressure transducer system

Description: A high precision pressure transducer system for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank. Since the response of the pressure transducer is temperature sensitive, it is continually housed in an battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum florescent display.
Date: December 31, 1992
Creator: Piper, T. C.; Morgan, J. P.; Marchant, N. J. & Bolton, S. M.
Partner: UNT Libraries Government Documents Department