摘要:

AbstractCapital cost correlations are given for oil‐water separators, equalization basins, primary clarifiers, clarifiers and clarifier mechanisms, reverse osmosis unit, ultrafiltration units, gravity filters and miroscreens. Data are included for raw sewage, intermediate and recirculation pumping stations and for preliminary treatment (or bar screens, grit removal, overflow and bypass chamber and Parshall flume), for grit removal, comminution and gas stripping. The correlations are accurate to ± 30%, expressed in Canadian dollars and adjusted to a Marshall and Swift value of 1000. Details as to what components are included in the cost are given. Data are given for the labour and material costs to create a working process module.For inflation indices, a critique of the Engineering News Record, EPA small city, Marshall and Swift, Chemical Engineering and Southam inflation indices suggested that the Marshall and Swift index is most appropriate for the construction and process equipment studied here. Concerning the currency exchange, for the equipment and processes in this study, equipment costs the same whether expressed directly in US or Canadian dollars.To put the current data into perspective, several hundred sources of cost data were analyzed. The major correlations are compared, on a consistent basis, with current da

ISSN:0008-4034    

DOI:10.1002/cjce.5450710411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe simplified version of the perturbed hard‐chain theory (SPHCT) developed by Kim et al. (1986) is modified by reformulating the attractive portion of the canonical partition function for mixtures, and replacing the repulsive portion by a simple simulated expression. The final equation of state developed is cubic in volume. The test results on pure fluids, binary/multi‐component mixtures and reservoir fluids indicate that the CSPHC EOS retains the advantages of the original PHCT, and significant improvements over the SPHCT in predicting the VLE of heavy hydrocarbon‐containing/CO2‐containing mixtures, and liquid phase density are o

ISSN:0008-4034    

DOI:10.1002/cjce.5450710412

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractAn analysis of variance for univariate feedforward/feedback systems has been derived which allows the variance contributions due to both disturbances and controllers to be established. A performance index which assesses the performance of the overall control scheme has been developed. Estimates of the analysis of variance and performance index can be obtained using ordinary closed loop data and least squares regression. These quantities can be used on‐line or off‐line for either the design of new controllers or as a means of assessing the performance of existing feedforward/feedback control schemes. The practicality of the results in the paper are demonstrated using simulated and industrial d

ISSN:0008-4034    

DOI:10.1002/cjce.5450710413

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractIn predictive control, control calculations are done such that the difference between the desired and the predicted response of the process is minimized. The number of points on the prediction horizon at which the error is minimized and the number of future control moves considered affect the on‐line computational effort involved in the solution of the constrained optimization problem. Earlier papers have shown that the control performance obtained using the DMC algorithm can also be obtained by using a simplified algorithm where the error is minimized at one point and one future control move is calculated. Because of its computational advantages, the simplified algorithm is analyzed further in this paper. Its transfer function is compared with the transfer function of the DMC algorithm. Characteristic equations to select tuning parameters are presented. The paper also compares the robust stability of the simplified and the DMC algorithms on SISO and MIMO process models. The results provide additional support to the viability of the simplified algorithm and thus indicate that it is possible for some processes to benefit from predictive control with only modest computational resource

ISSN:0008-4034    

DOI:10.1002/cjce.5450710414

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractA new constrained self‐tuning PID controller is developed based on Clarke and Gawthrop's (1975) generalized minimum variance (GMV) controller. Convergence properties for the new algorithm are derived and the effect of the constraint parameter is evaluated. Extension of the controller to include more than the usual three PID parameters occurs naturally. No process model information is required for our algorithms except the dead time. This is an improvement over other algorithms which impose severe constraints on the process structure.The controller algorithm is tested on a variety of models using simulation as well as under experimental conditions. The algorithm is easy to implement and compares favourably with the more complex GMV controlle

ISSN:0008-4034    

DOI:10.1002/cjce.5450710415

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractA new resolution strategy is presented to overcome short‐comings of the sequential modular process flowsheeting. Following a logic flow of information, different from the material flow of streams in the flowsheet, changes the mathematical structure of the system of equations that models the units. New programs have been generated, very different from traditional modules.Deciding an appropriate resolution strategy usually leads to a dramatic reduction in required CPU times and to an increased flexibility to handle different problems. The simulation convergence and process optimization can be approached from a different perspectiv

ISSN:0008-4034    

DOI:10.1002/cjce.5450710416

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractDeveloping flows of generalized Bingham (Herschel‐Bulkley) fluids in concentric annuli were studied numerically. A control volume approach based upon an upwinding finite difference technique was used to solve the equation of motion. The results in terms of velocity and pressure drop profiles are shown graphically. Radius ratios of 0.02, 0.2, 0.4 and 0.6; power‐law indices (n) of 0.7, 1.0 and 1.2; generalized Bingham numbers of 5, 10 and 15 were investigated. At present, there are no experimental results with which to make comparisons. However, there are results for fully developed flows and comparison has been made with these. In all cases the agreement was g

ISSN:0008-4034    

DOI:10.1002/cjce.5450710417

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

摘要:

AbstractThe slow non‐Newtonian (inelastic) flow through packed beds of mono‐size spherical particles has been simulated by solving the equations of motion numerically. The inter‐particle interactions have been modelled by using a simple cell model. Theoretical estimates of pressure, friction and total drag coefficients as function of the pertinent physical (l≥n≥ 0.2; 0.3 ≤ e ≤ 0.5) and kinematic parameters (0.01 ≤ '≤ 100) for a fixed value of Reynolds number {Re= 0.001) have been obtained. The theoretical predictions reported herein have been validated using the suitable experimental results available in the literature, and the importance of including the zero shear viscosity in analyses for the creeping flow problems is convinci

ISSN:0008-4034    

DOI:10.1002/cjce.5450710418

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY

ISSN:0008-4034    

DOI:10.1002/cjce.5450710419

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1993

数据来源: WILEY