摘要:

Operation of a continuous rotary dissolver, designed to leach uranium-plutonium fuel from chopped sections of reactor fuel cladding using nitric acid, has been automated. The dissolver is a partly continuous, partly batch process that interfaces at both ends with batchwise processes, thereby requiring synchronization of certain operations. Liquid acid is fed and flows through the dissolver continuously, whereas chopped fuel elements are fed to the dissolver in small batches and move through the compartments of the dissolver stagewise. Sequential logic (or machine control) techniques are used to control discrete activities such as the sequencing of isolation valves. Feedback control is used to control acid flowrates and temperatures. Expert systems technology is used for on-line material balances and diagnostics of process operation.

ISSN:0098-6445    

DOI:10.1080/00986449308936183

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A first order irreversible reaction is investigated using a stochastic model in order to account for the perturbations inherent to any chemical process. The main conclusion is that the concentration is distributed according to a lognormal law rather than to a normal one. This approach leads to a maximum likelihood estimate of the kinetic constant which is different with respect to the usual least squares estimate. Moreover, the stochastic model allows us to predict not only the expected value of the concentration, but to get a confidence interval, too. Statistical tests are provided in order to detect outliers, high-leverage and influential points.

ISSN:0098-6445    

DOI:10.1080/00986449308936184

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The jet bubble column consists of a conical entrance section which expands to a cylindrical column. Gas and liquid are co-currently introduced at the bottom of the column by a small diameter inlet pipe which acts like an ejector. The kinetic energy of the gas and liquid jet together with the conical geometry at the lower section of the column cause the formation and dispersion of small bubbles.

ISSN:0098-6445    

DOI:10.1080/00986449308936185

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The corresponding states and extended corresponding states principles have been evaluated for refrigerants. In the two corresponding states techniques the Riedel and Wagner vapour pressure correlations have been used to express the vapour pressure for the reference fluids. As reference fluids CFC12 and HFC134a have been used. These two fluids cover the acentric factor interval wherein refrigerants are found. Parameters have been estimated for CFC12 and HFC134a according to the Reidel and Wagner vapour pressure correlations used in the extended corresponding states principle. Experimental vapour pressure data for CFC12 and HFC134a have been used to estimate parameters according to Riedel and Wagner used in the hypothetical fluid and deviation function used in the corresponding states principle.

ISSN:0098-6445    

DOI:10.1080/00986449308936186

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The environmental constraints coming into place on aromatics in petroleum products makes it necessary to develop an analytical technique that explicitly accounts for their effect. Furthermore, the multicomponent nature of petroleum fractions makes it difficult to analyze feed composition sensitivities without a large number of tests. This paper presents a convenient way to analyze the sensitivity or, as sometimes called, the switchabilily of petroleum fractionators. The technique depends on “lumping” all the paraffinics, naphthenic and aromatic components into three “pseudo components”:P, NandA.

ISSN:0098-6445    

DOI:10.1080/00986449308936187

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Thermodynamic equilibrium constants for the liquid-phase synthesis of ethyl terl-butyl ether (ETBE) were determined experimentally in the temperature range 40-80°C (313-353 K) at 1.6 MPa for an initial molar ratio of ethanol to isobutene ranging from 1 to 1.5. To reach etherification equilibrium a macroporous sulphonic acid resin (K-2631, Bayer) was used as a catalyst. The thermodynamic equilibrium constant and the enthalpy, free energy, and entropy changes are given as a temperature function. At 298 K, ΔH° = −34.8 kj mol−1, ΔG° = −11.7kJmol−1, and ΔS° = −77.3J mol−1K−1. A comparison with the values obtained for MTBE is also included.

ISSN:0098-6445    

DOI:10.1080/00986449308936188

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor