ISSN:0021-1915    

DOI:10.1080/10256019008624345

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Tracers can be used to label substances or objects in order to discriminate between them, to follow their movement, to record changes of concentration and distribution between phases, etc. The main advantages of tracer investigations are the contactless recording of signals without influencing the observed process (also under rigorous operation conditions), the high detection sensitivity, the large number of available tracer nuclides (problems of all branches of industry can be solved) and the fact that tracer investigation can be carried out on operating production units, so that they provide valuable checks of the validity of design and process data. The cost-to-benefit ratio can be as low as 1:50. In the following some selected examples of tracer applications carried out by the staff of the Central Institute of Isotope and Radiation Research and their benefits will be presented.

ISSN:0021-1915    

DOI:10.1080/10256019008624346

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Radiotracer methodology applied to troubleshooting and process improvement provide substantial economic benefits in petroleum refining. The benefits derive from rapid identification of operating problems, reduction of unscheduled shutdowns or shorter downtime; and improvements in processing operations, operating efficiency, product quality and yield. The costs for performing tracer studies is small compared to the benefits obtained. Refinery examples are given and the benefits are expressed in dollars wherever possible. Wider use of this technology promises greater benefits throughout all industry.

ISSN:0021-1915    

DOI:10.1080/10256019008624347

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Utilization of radiotracer methodology in industrial research provides substantial scientific rather than directly demonstrable economic benefits. These benefits include better understanding of industrial processes and subsequently the development of new ones. Examples are given of the use of radiotracers in technological studies and the significance of the obtained results is put down. Creative application of radiotracer methodology may contribute to the economic development and technological advancement of all countries including the developing ones.

ISSN:0021-1915    

DOI:10.1080/10256019008624348

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A variety of applications of radiotracers are in vogue in industries with significant economic advantage. Some of the applications in steel, petroleum and maritime industries provide interesting case studies. Different approaches are possible for arriving at the cost to benefit ratio. These include: (1) direct cost comparison with alternative technique, (2) savings due to increased production and reduction in interruption of process, (3) savings due to avoidance of infructuous expenditure.

ISSN:0021-1915    

DOI:10.1080/10256019008624349

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Simple relations are given, which could help to estimate the expected annual savings resulting from the application of radioisotope methods for the mixing time, segregation effect or residence time distribution determination. Criteria for estimation of benefit at optimum transition of the continuous production from one quality to another, criteria for estimate the benefits on basis of known holdup and for estimate of benefits resulting from knowledge of the distribution function of residence time and of the kinetics of chemical reaction are presented. Further are demonstrated two examples of evaluation of the economic effect of the results of a system analysis in chemical industry where beside the measurements od residence time distribution by help of radiotracers are used also results of other experimental methods and that practically without increasing production cost.

ISSN:0021-1915    

DOI:10.1080/10256019008624350

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Continuous flow vessels which are subject to variation of flow and volume are characterized by time-variable parameters. It is shown that their residence time distributions and weighting functions obtained by tracer testing are made invariant with regard to the integrated flow variables which are introduced. Under variable flow but constant volume, one such integrated variable is sufficient. Under variable volume, two different variables are suggested for the residence time distribution and weighting function, while the appropriate variable of the perfect mixer differs distinctly from that of vessels with a distinct velocity profile. It is shown through a number of example cases, that an agreement with their mathematical models is reached. The approach is extended to include also arbitrary, non-analytic response functions obtained by tracer measurements. Applications of the derived models and their incorporation in automatic control algorithms is discussed.

ISSN:0021-1915    

DOI:10.1080/10256019008624351

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

One of the most difficult operations for control and identification in copper ore concentration process is grain classification in hydrocyclone batteries. In the paper radiotracer investigations of the classification process immediately give values of hydrocyclones parameters with higher accuracy than obtained from conventional methods. Presented paper includes the results of the investigation which was carried out in “Lubin” Copper Mine in Poland.

ISSN:0021-1915    

DOI:10.1080/10256019008624352

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Space scanning with a narrow gamma beam in several positions in the plane cross-section of a tested equipment provides the information on bulk densities on the basis of which the values of solid particles local concentrations can be evaluated. The approximative functions appropriate for the description of the local concentrations in a plane are chosen in dependency on the character of the measured system, usually in the form of polynomial, containing a selected number of constants. The values of these constants are determined from a set of algebraic equations which are derived from the approximative functions. The accuracy of the computation depends on the conditionality of the set of these equations. The suggested method of the evaluation determines the optimal number of constants in the approximative functions. The necessary number of scannings in one cross-section is discussed. The method has been applied for the evaluation of the space distribution of solid particles in two systems i.e. the mechanical mixing of suspensions which can be considered as having a symmetrical concentration distribution and the fluidization of powders which can be considered as having an arbitrary concentration distribution.

ISSN:0021-1915    

DOI:10.1080/10256019008624353

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The extraction of UO2+2from nitric acid solutions by two neutral donors ligands (L), triphenylarsine oxide (Ph3AsO) and triphenylphosphine oxide (Ph3PO), in chloroform is investigated. At low HNO3acid concentrations (<2 M), UO22+is highly extracted as simple cation by Ph3AsO and slightly extracted by Ph3PO. The extraction constant of UO22+from low nitric acid medium is found to equal 1212 ± 120. At higher HNO3concentration (>2 M), UO22+is extracted by ion association mechanism as UO2(NO3)2- 2L, and the distribution ratio of UO22+using Ph3PO is found to be higher than that of Ph3AsO. This is interpreted by the extraction competition of HNO3for Ph3AsO. Spectroscopic investigations in the visible and IR regions supported the results obtained.

ISSN:0021-1915    

DOI:10.1080/10256019008624354

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor