Asian Journal of Water, Environment and Pollution, Vol. 2, No. 1, pp. 93-101.
A Computer Programme for Recycled Quantity Estimation of Solid Wastes I.O. Popoola and S.A. Oke1* Department of Mechanical Engineering Faculty of Engineering, University of Lagos, Lagos, Nigeria
[email protected],
[email protected] Received July 7, 2004; revised and accepted November 10, 2004
Abstract: Recent advances in computer technology have provided the tools and the environment for the industrial engineer to study, analyse, and better understand complex systems. This technological development has enabled the industrial engineering professional to collect and analyse massive amounts of data to scale previously not possible. Industrial engineers have made immense contributions in diverse systems such as telecommunications, healthcare, transportation, oil and mineral exploration, etc. with great impacts on the lives of human beings. The impact of this technology is now being felt in the environmental field in collaborative research with environmental scientists and mathematicians to improve the solid waste recycling system. In this work, a computer programme is developed for one of such efforts. In particular, an estimation of the net output per unit time of the system is made i.e. the quantity of a recycled material that could be produced over a period of stipulated time. The programme accepts input, performs the necessary calculations and produces the results in a format indicating the output. Key words: Computer programme, recycling, industrial engineering, technological advancement
Introduction Serious investigations on waste recycling emerged several decades ago with authors concentrating on qualitative measures of recycling performance. However, of late, intensive efforts have been diverted to modelling problem on quantitative research in recycling. While these quantitative measures appear to dominate the field in recent times, there seems to be a re-occurring gap in the literature with respect to programming (see Ecevit et al., Fleck, Mckenna and Partridge). To date, there is no reported case of programming the recycling problem. This has therefore thrown a challenge to the environmental research and the wider academic communities. In this work, our focus is to develop a computer programme that reliably estimates the quantity of recycled solid waste generated. The aim is to use a programme that is scientific, easy to understand and *
Corresponding Author
current in today’s practice. In particular, the development tool used is QBASIC. The software has the advantage of being widely applicable in the scientific community. The programme is conceptualized from four main perspectives: system analysis, system synthesis, programme development and experimentation. System Analysis This is a highly valuable tool necessary to implement the solution of a problem. Here, we took a pragmatic approach to the identification of the problem areas in our model, their analysis and the design of practical economic solution towards solving the recycling problem. As presented here, the system analysis approach provides a framework which, when further studied, can expand into a well-developed knowledge area with wide ranging subjects. System analysis was initiated with discussions with experts on plastics recycling. In particular, two established plastic industries engaged in recycling were visited. The case for two
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industries is considered in order to guarantee the precision of results obtained and as a check towards some undisclosed values by experts in the system, so that the opportunity would not generate into market advantage through knowledge of the technical weakness of the other companies. The methods used include actual field observation on the recycling process, extensive discussion with experts and operatives of the various facilities used for recycling, and indirect questionnaire approach. This stage is meant to give the researcher a broad understanding of the recycling process, system and the principles to adopt for an efficient and cost effective recycling. Consequently, our visit to the industries gave us a good understanding of the working principles and operations of the major equipment used in recycling plastics. System Synthesis Usually, the next stage after the analysis is to synthesize the system by assembling the gathered information. These materials are then examined so that linkages and inter-relationships could be established before the model development. From our familiarization with the equipment and a good understanding of its working systems, the principles of fluid mechanics offers a very useful idea in synthesizing the current problem. Thus, we established a linkage between the fluid mechanics and plastic behavioural concepts. This led into model development. Programme Development Having developed the model, the input and output parameters were specified. We proceeded by developing a computer programme algorithm, which assisted in developing the computer programme. The appendix contains the programme for the problem solved. The programme, already provided with some input from the user with the DATA statement, after being run, produces the output in an output file created inside the computer. At the end of the programme operations, output files can be obtained on hard copy by printing out. Experimentation This is carried out using simulated data in view of the difficulties encountered in obtaining them from both of the plastics industries. Mainly because they seldom keep complete records of operations. For this reason, the simulated data were used to express the potential capabilities of the model. This experimentation was performed using the programme on a microcomputer preloaded with a Microsoft Visual Basic Module.
The input parameters are screw diameter, D; channel depth, h; channel width, W; helix angle, q; and metering zone length, L. The expected outputs from the programme are screw constant, A; screw geometric constant, B; drag flow, QD; pressure flow QP; and flow rate, Q. The programme developed in this work is aimed at generating a sequence of steps to calculate the flow rate of the recycled product. The case of plastic materials is assumed with most of the parameters determined with due consideration for the material for recycling. This flow rate is designated as Q, expressed in m3/s. This is meant to generate the actual quantity of volume of the recycled product per second. The application of this quantity estimation to the industry lies in the case of determination of specific quantities to be produced from certain configured materials. In addition to the flow rate, the programme also generate values for the screw constant A, and the screw geometry constant, B, which in effect helps the industry to determine the constants A and B of the extruder machines. The justification for two screw constants in the above statement lies in the fact that we have different screw constants for every extruder machine. However, if we have a particular flow rate to be generated, we can in turn simply regulate the screw speed of the machine to obtain it. Also, it provides values for the drag flow, QD, and pressure flow, Q P. These are some important quantities that should be noted for different extruder machines. Knowing the drag flow and pressure flow helps the industry to regulate in order to achieve a particular desired flow rate, Q.
Related Literature The following is a review of relevant literature pertaining to the current work. In an article by Miller and Ulrich (2004), a computer programme christened PMERTIC was developed for the analysis of the observed psychometric functions. It can estimate the parameters of these functions, using either probit analysis (a parametric technique) or the Spearman-Karber method (non-parametric one). The programme can be used to analyze data obtained from either Yes-No or m-alternative forced-choice tasks. To facilitate the use of PMETRIC in simulation work, an associated programme, PMETGEN, is provided for the generation of simulated psychometric function data. Use of PMETRIC is illustrated with data from a duration discrimination task. Evidently, this reviewed work is a pointer to the many aspects of the recycling
A Computer Programme for Recycled Quantity Estimation of Solid Wastes
waste process that should be computerized. The model developed in a previous work consists of important parameters such as screw diameter, channel depth in the metering zone, flow width, helix angle of the screw, screw speed in revolutions per second, linear velocity and channel width parallel to the screw axis. An insight into the development of modules for the solid waste recycling process is therefore given by Miller and Ulrich. In another work, a computer programme that measures body size distortion and body dissatisfaction was described by Gardner and Boice (2004). The programme is written using visual basic development tools and will run on any windows 98 or more current system. From the work, we gained an understanding of the more frequently accessible operating system – windows operating platform. Thus, the programme developed in our work could be conveniently loaded on Windows operating system, ‘98’ version and above. In another study, an integrated farming approach for runoff recycling systems in humid plateau areas of eastern India was carried out by Srivastava et al. (2003). The authors comment that regions having undulating terrain are predominantly rainfed and have a poor productivity level. As the traditional irrigation systems, viz. canal irrigation and tubewell irrigation are not feasible due to topographical, geological and hydrological constraints, rainwater harvesting has been found to have potential of being an irrigation water source which can provide full irrigation in conjunction with rainfall to a transplanted rice based two-crop rotation. Utilisation of stored water in both monsoon and postmonsoon season crops increases the efficiency of the system that is evident from higher water yield-storage capacity of 1.75. The evaluation of a rainwater harvesting system has shown that integrated farming approach of utilising the system enhances the economics of the system. While the B-C ratio with only one crop was 1.89, it was increased to 2.27 if horticultural crops are taken on the embankment of the tank. It further increased to 2.80 when fish culture is taken up in the stored water. There is possibility of it increasing to more than 3.0 if duckery is also taken up. Extrapolating these results, benefit cost analysis has been done for other two site conditions where the seepage loss is between 6 and 10 mm/day and seepage loss is more than 10 mm/day and therefore lining is required. The lessons learnt from Srivastava et al. is the possible application of the computer programme developed here to agricultural setting by adopting some of the parameters discussed.
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A study by Farag and Mohammed (1999) evaluated a rain water harvesting system. It shows that integrated farming approach of utilizing the system enhances the economies of the system. The study is of primary importance to the recycling community in that it shows an addition to knowledge in this ever-growing area. Unfortunately, no indication has been made on the usefulness of computer programme in simplifying the computational procedure of the recycling process. This is an important gap that the present work attempts to fill. A study by Ardente et al. (2003) describes a model, named “ENDLESS”, useful to address the design process towards more eco-compatible solutions. In particular, this tool can support the designer in the choice of the product with a higher recyclability potential from a set of different alternatives. The model takes into consideration a multi-attribute decision-making method and allows calculating a “Global Recycling Index” (GRI) starting from a set of energy, environmental, technical and economic indicators. A weight is assigned to each parameter following the experience of the designer and a sensitivity analysis is then performed to state how the different assumptions can affect the final results. The model is implemented in software and applied to a casetudy: to establish the best recyclability option of middle and low voltage electrical lines used for electricity distribution in Italy. While this study offers an important contribution to software development, in eco-sustainable environment, little assistance is offered on how to apply this to the recycling project. The model helps us to add a multi-attribute inclination to the computer programme that we are developing in this work. As such, it may be beneficial if some important dimensions of the software project could be established. The issues of cost, optimization, profitability and sensitivity of the recycling model may add value to the multi-dimensional viewpoint of the model. Another important research was carried out by Thormark (2001) on the recycling of building waste. The purpose of the study was to assess the conservation of energy and natural resources and the amount of material to landfill by recycling were compared with the recycling rates applied in 1996. The scenarios were ‘maximum material recycling/combustion with energy recovery’ and ‘maximum reuse’. The results indicate considerable conservation of resources and a considerable growth potential. Possibilities, constraints and needs for further studies are discussed. The results also indicate that the recycling aspects must be considered already in the design phase. Although, this author has considered a
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relevant recycling project, the paper does not discuss the important details of the recycling process such as flow rate, etc. Thus, there is a gap between the state of knowledge on recycling and what the paper currently aims to address. This justification for writing a computer programme on solid wastes recycling flow rate also comes from the absence of such programmes in the work of Zabaniotou and colleague (1998). The study applies modern recycling technologies in accordance with the European and Greek legislation, aiming at the recovery of lead, polypropylene and sulfuric acid from spent lead (Pb)/ acid batteries. The present state of their disposal and exploitation is also depicted. The international situation is reviewed, and the general trends marked.
programmer can run this and the results are expected to remain the same. If some technicalities are involved like plotting of graph or drawing of lines, it would have been worth while for the producer to consider a better programming software. For this work the application of the QBASIC programme is just enough to suit the purpose. Applying any other programming software or technique will simply involve more technicalities which needs more time, in learning and resources in purchasing the software to run the developed programme and test its correctness.
The development of the SOLIDCYC programme discussed here follows two perspectives: producers and consumers. From the producer’s perspective we consider accuracy, capability, features, completeness, conformance, serviceability, stability and structuredness. However, from the consumer’s perspective, we discuss the subjects of capability, communication, completeness, conformance, features, flexibility, simplicity, and stability. The following are relevant discussion to those items.
Features The features in this work do not express so much technically. This is as a result of the elementary stage it is still processed. It could be later developed to incorporate features like password requirement to make use of it. Another possible feature that could have been incorporated is the ability to dictate the units desired by the producer to produce the results. It has only been developed to give results based on the unit of the input parameters. This might not be enough to meet up with the consumer’s desire. As a result, it should therefore be improved. The basic feature shown is the result that is produced directly as soon as the user runs the programme. This is so because the INPUT statement had been dropped for the READ and DATA statement. This feature can also be improved.
Accuracy The programme has been developed in QBASIC since it is a simple and widely used programme for several decades. Although, it is not as advanced and technical compared to some newly developed programming language such as C++, JAVA, etc it is easier to understand its statements and apply. When errors occur, debugging activities are made easy with some of its embedded features. The debugging procedure starts with a highlight of the line with the error. With the understanding from the development of statements in QBASIC, corrections are easily made. Moreover, QBASIC might not be the best programming language in terms of calculating with exactness but with the ease in understanding its fundamental technicality and application, this work have chosen it for the users benefit.
Completeness In terms of completeness the basic aim of the programme which is for computational ease of the various parameters of the outflow of the recycled products have to be achieved. The screw constant, A and geometry screw constant, B, are both produced as part of results. These give very important properties that describe each extruding machine uniquely. These properties are both used to determine the drag flow, Q2D and pressure flow, QP which are the major constituents that makes up the flow rate, Q, the model actually generates. It is therefore correct to a large extent to express that this work is complete with respect to the basic aim. But considering some additional features that might be desired by the consumer, this programme has not been able to incorporate so many but it could later be developed.
Capability From the statements employed in developing the programme, it can be deduced that SOLIDRECYC is less complicated than most programmes. The model being programmed is a linear type and almost every
Conformance The best means of expressing this is in one of the limitations of QBASIC programming language. In a case where exponential values that probably turns very high, there would be a run over. This implies that the
Programming Perspectives
A Computer Programme for Recycled Quantity Estimation of Solid Wastes
programme is not large enough to compute very large values. With respect to the model developed in this work, it is true that the model conforms to QBASIC programme. This is because the values of all parameters involved are within reasonable range of values that could be handled conveniently by the software. As a result, from the producer’s perspective, it conforms. From the consumer’s perspective, conformance is best examined from the possibility of running the programme on his computer. This means the conformity of the programme to the type of operating system the consumer uses. The types of operating system in use in the computer technological world today are UNIX, LINUX, Macintosh and windows operating systems. Whichever the operating system, the programme will confirm based on the fact that all software should work under any window. Window is built to operate under DOS environment; it should accept any software like QBASIC. However, perhaps the most common operating system is the windows platform. Hence, the programme developed here runs on window operating system. Communication This literally means passing messages or information across. In this case, the programme has been written to give the software necessary steps to follow that gives exactly what the user (consumer) requires. The first information required by the programme from the user is either inform of input (in a case of INPUT statement) or data (in a case of READ and DATA statement). This is entered into the system with the keyboard and the response from the programme is to simply produce the result on the screen after following the specified steps by the statements used in the programme. The situation where there might be an error in the response is when any of the values is too large for the software to accommodate and, as explained earlier, gives a system overflow. Flexibility This describes the response of the programme to variations in the input data. It measures how much variation it can withstand to still produce reasonable and practicable results. Unfortunately, the READ and DATA statement used in this programme does not allow for much flexibility. Each time the user desires to compute for a new set of data, he needs to return back to the programme where the adjustment would be made. This requires more caution from the user in order not to damage the programme by deleting any important aspect
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of the programme. For this purpose, it would be more flexible if only the READ and DATA statements could simply be changed to INPUT statement. The moment the adjustment is made, many data could be run at different instances and the right results will still be obtained.
Discussions of Results For the very sake of computational ease, the need for computer programming becomes essential to any field involving modeling. The nature of the models dictates the complexity of the choice programme to be employed. In this case, the model is not too complex in nature. It’s a model of linear property except for some parameters that are squared and cubed. For this reason, despite the non-complexity, it is still necessary to consider the programming of the model to reduce the error that may result from the computation of those parameters with squares and cubes. The type of programme used for this purpose is QBASIC. Though it has been in existence long time ago, as one of the original programming technique employed in history, it is found to be widely established and easy to understand by any individual who could dedicate some time of rigorous study of the various statement to perform various function to achieve the goal of the model being programmed. To a learned individual about QBASIC, two statements could be applied interchangeably READ-DATA statement and INPUT statement. For the previous, the data to be used in running the programme has been incorporated already by the programmer such that the user would straightaway have the output given. While the later is such that during the running process of the programme, the user is in the position to input the data to get the output. In this work, the former was applied to directly obtain the output for the simulated data considered in the whole project work. For the purpose of multiple use for various data of any kind, the programmer would simply shift to the application of INPUT statement by replacing the statement READ by INPUT and completely eradicating the DATA statement from the programme. The implication of this is that the computer will request for the input data during the running process.
Conclusions This work has been successful in writing a computer programme that would assist in the computation of the mathematical model developed in a previous research. It is hoped that it has been able to achieve the very aim
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of assisting in the computation of the model in the industry, thus reducing to the minimum the possibility of error in the output required by the plastic recycling engineer. Another contribution this makes to the industry is to reduce the time it takes to accomplish the computation. It might actually take a longer time for the individual making the computation each time he tries to compute for a new set of data. Instead of this, the shorter time have been used in developing the computer programme once and after which little time is required to enter the data during the running process. Since time and expenses are of great importance to the recycler, the computer programme developed serves as a very important tool to achieve great progress and profit.
References Ecevit, Y., Gunduz-Hosgor, A. and C. Tokluoglu (2003). Women in computer programming operations: the case of Turkey. Development International, 8(2): 78-87.
Fleck, R.A. (2004). Managing programmer resources in a maintenance environment with function points. Industrial Management and Data Systems, 98(2): 63-70. Gardner, R.M. and R. Boice (2004). Computer program for measuring body size distortion and body. Behaviour Research Methods, Instruments & Computers, 36(1): 8995. McKenna, P. (2000). Transparent and opaque boxes: do women and men have different computer programming psychologies and styles? Computers and Education, 35(1): 37-49. Miller, J. and R. Ulrich (2004). A computer program for Spearman-Karber and probit analysis of psychometric function data. Behaviour Research Methods, Instruments & Computers, 36(1): 11-16. Partridge J.R. and B.H. Kleiner (1992). Managing computer programmers effectively. Industrial management and Data Systems, 92(8). Srivastava, R.C., Singhandhupe, R.B. and R.K. Mohanty (2003). Integrated farming approach for runoff recycling systems in humid plateau areas of eastern India. Agricultural Water Management, 64(3): 197-212.
Appendix: Tables of Simulated Values Table 1 Diameter, D %D Value (m) –100 0 –95 0.003 –90 0.006 180 0.168 185 0.171 190 0.174 195 0.177 200 0.18
h (m) 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003
W (m) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
L (m) 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25
N (rps) 1.67 1.67 1.67 1.67 1.67 1.67 1.67 1.67
ma (Pa.s) 1750 1750 1750 1750 1750 1750 1750 1750
P (Pa)
q (rad.)
5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07
0.785 0.785 0.785 0.785 0.785 0.785 0.785 0.785
P (Pa)
q (rad.)
Flow Rate, Q Value (m3/s) –1.82E-06 –1.23E-06 –6.38E-07 3.12E-05 3.18E-05 3.24E-05 3.30E-05 3.36E-05
%D –118.2 –112.3 –106.4 212.77 218.68 224.59 230.51 236.42
Table 2 Channel Depth, h %D Value (m) –100 0 –95 0.00015 –90 0.0003 180 0.0084 185 0.00855 190 0.0087 195 0.00885 200 0.009
D (m) 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06
W (m) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
L (m) 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25
N (rps) 1.67 1.67 1.67 1.67 1.67 1.67 1.67 1.67
ma (Pa.s) 1750 1750 1750 1750 1750 1750 1750 1750
5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07
0.785 0.785 0.785 0.785 0.785 0.785 0.785 0.785
Flow Rate, Q Value (m3/s) 0 5.9E-07 1.179E-06 –6.862E-06 –8.449E-06 –1.011E-05 –1.186E-05 –1.368E-05
%D –100 –94.09 –88.2 –168.7 –184.6 –201.3 –218.7 –237
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Table 3 Channel Width, W %D Value (m) –100 0 –95 0.0025 –90 0.005 180 0.14 185 0.1425 190 0.145 195 0.1475 200 0.15
D (m) 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06
h (m) 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003
L (m) 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25
N (rps) 1.67 1.67 1.67 1.67 1.67 1.67 1.67 1.67
ma (Pa.s) 1750 1750 1750 1750 1750 1750 1750 1750
P (Pa)
q (rad.)
5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07
0.785 0.785 0.785 0.785 0.785 0.785 0.785 0.785
P (Pa)
q (rad.)
Flow Rate, Q Value (m3/s) 0 4.9931E-07 9.9863E-07 2.7962E-05 2.8461E-05 2.896E-05 2.9459E-05 2.9959E-05
%D –100 –95 –90 180 185 190 195 200
Table 4 Metering Zone Length, L %D Value (m) –100 0 –95 0.0625 –90 0.125 180 3.5 185 3.5625 190 3.625 195 3.6875 200 3.75
D (m) 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06
h (m) 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003
W (m) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
N (rps) 1.67 1.67 1.67 1.67 1.67 1.67 1.67 1.67
ma (Pa.s) 1750 1750 1750 1750 1750 1750 1750 1750
5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07
0.785 0.785 0.785 0.785 0.785 0.785 0.785 0.785
P (Pa)
q (rad.)
Flow Rate, Q Value (m3/s) #DIV/0! –2.456E-5 –6.378E-6 1.116E-5 1.117E-5 1.118E-5 1.119E-5 1.12E-5
%D #DIV/0! –345.9 –163.9 11.705 11.819 11.929 12.036 12.139
Table 5 Screw Speed, N %D Value (rps) –100 0 –95 0.0835 –90 0.167 180 4.676 185 4.7595 190 4.843 195 4.9265 200 5.01
D (m) 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06
h (m) 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003
W (m) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
L (m) 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25
ma (Pa.s) 1750 1750 1750 1750 1750 1750 1750 1750
5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07
0.785 0.785 0.785 0.785 0.785 0.785 0.785 0.785
P (Pa)
q (rad.)
Flow Rate, Q Value (m3/s) –1.818E-06 –1.228E-06 –6.378E-07 3.1234E-05 3.1825E-05 3.2415E-05 3.3005E-05 3.3595E-05
%D –118.2 –112.3 –106.4 212.77 218.68 224.59 230.51 236.42
Table 6 Apparent Viscosity, ma %D Value(Pa.s) –100 0 –95 87.5 –90 175 -
D (m) 0.06 0.06 0.06 -
h (m) 0.003 0.003 0.003 -
W (m) 0.05 0.05 0.05 -
L (m) 1.25 1.25 1.25 -
N (rps) 1.67 1.67 1.67 -
5.00E+07 5.00E+07 5.00E+07 -
0.785 0.785 0.785 -
Flow Rate, Q Value (m3/s) #DIV/0! –2.46E-05 –6.38E-06 -
%D #DIV/0! –345.9 –163.9 (contd.)
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Table 6 (contd.) 180 185 190 195 200
4900 4987.5 5075 5162.5 5250
0.06 0.06 0.06 0.06 0.06
0.003 0.003 0.003 0.003 0.003
0.05 0.05 0.05 0.05 0.05
1.25 1.25 1.25 1.25 1.25
1.67 1.67 1.67 1.67 1.67
5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07
0.785 0.785 0.785 0.785 0.785
ma (Pa.s)
q (rad.)
1.116E-05 1.117E-05 1.118E-05 1.119E-05 1.12E-05
11.705 11.819 11.929 12.036 12.139
Table 7 Pressure, P (Pa) %
Value (Pa) –100 0.00E+00 –95 2.50E+06 –90 5.00E+06 180 1.40E+08 185 1.43E+08 190 1.45E+08 195 1.48E+08 200 1.50E+08
D (m) 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06
h (m) 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003
W (m) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
L (m) 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25
N (rps) 1.67 1.67 1.67 1.67 1.67 1.67 1.67 1.67
1750 1750 1750 1750 1750 1750 1750 1750
0.785 0.785 0.785 0.785 0.785 0.785 0.785 0.785
ma (Pa.s)
P (Pa)
Flow Rate, Q Value (m3/s) 1.18E-05 1.171E-05 1.162E-05 6.713E-06 6.622E-06 6.532E-06 6.441E-06 6.35E-06
%D 18.21 17.3 16.39 –32.8 –33.7 –34.6 –35.5 –36.4
Table 8 Helix Angle, q %D Value (rad.) –100 0 –95 0.03927 –90 0.07854 180 2.199115 185 2.238385 190 2.277655 195 2.316925 200 2.356194
D (m) 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.06
h (m) 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003
W (m) 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
L (m) 1.25 1.25 1.25 1.25 1.25 1.25 1.25 1.25
N (rps) 1.67 1.67 1.67 1.67 1.67 1.67 1.67 1.67
1750 1750 1750 1750 1750 1750 1750 1750
5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07 5.00E+07
Flow Rate, Q Value (m3/s) 2.104E-05 2.1E-05 2.09E-05 9.668E-06 1.064E-05 1.163E-05 1.262E-05 #DIV/0!
%D 110.67 110.32 109.29 –3.185 6.5542 16.439 26.412 #DIV/0!
Qbasic Programme for the Computation of Flow Rate The programme was developed on MS-DOS QBASIC software and was run on the executable file. The executed programme with the output are given below: Programme 10 REM “FLOW RATE” 20 REM D REPRESENTS “SCREW DIAMETER” 30 REM L REPRESENTS “METERING ZONE LENGTH” 40 REM W REPRESENTS “CHANNEL WIDTH PARALLEL TO THE SCREW AXIS” 50 REM h REPRESENTS “CHANNEL DEPTH IN THE METERING ZONE” 60 REM F REPRESENTS “ANGULAR DISPLACEMENT(IN RADIANS)” 70 REM A REPRESENTS “SCREW CONSTANT” 80 REM B REPRESENTS “SCREW GEOMETRY CONSTANT” 90 REM N REPRESENTS “SCREW SPEED(IN REVOLUTIONS PER SECONDS)” 100 REM P REPRESENTS “PRESSURE” 110 REM Ua REPRESENTS “APPARENT VISCOSITY”
A Computer Programme for Recycled Quantity Estimation of Solid Wastes
120 REM QD REPRESENTS “DRAG FLOW” 130 REM QP REPRESENTS “PRESSURE FLOW” 140 INPUT “D=”, D 150 INPUT “h=”, h 160 INPUT “W=”, W 170 INPUT “F=”, F 180 CONST PI = 3.141593 190 LET A = (PI * D * h * W * (COS(F)) ^ 2) / 2 210 INPUT “L=”, L 220 LET B = (h ^ 3 * W * COS(F)) / (12 * L) 240 INPUT “N=”, N 250 LET QD = A * N 270 INPUT “P=”, P 280 INPUT “Ua =”, Ua 290 LET QP = (B * P) / Ua 310 LET Q = QD - QP 320 PRINT “A=”; A 322 PRINT “B=”; B 323 PRINT “QD=”; QD 325 PRINT “QP=”; QP 328 PRINT “Q=”; Q 330 END Input D=0.06 h=0.003 W=0.05 F=0.7854 L=1.25 N=1.67 P=50E6 Ua =1750 Output A=7.068559E-06 B=6.36395E-11 QD=1.180449E-0 QP=1.818271E-0 Q=9.986221E-06
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