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ISSCT XXVIth CONGRESS Durban, South Africa 29th July - 2nd August 2007 |
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FACTORY
COMMISSION ENGINEERING PAPERS
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ISSCT XXVIth CONGRESS
Durban, South Africa
29th July - 2nd August 2007
FACTORY COMMISSION
Papers & Posters Titles
(Click on titles to access Abstracts)ENGINEERING PAPERS
PROCESSING PAPERS
FP1
The effect of final effect operating pressure on sucrose degradation in evaporator stations
S.D. Peacock - South AfricaFP5
Glyphosate ripener effects on the processing quality of different sugarcane tissues
G. Eggleston, R. Viator and M. Grisham - USAFP7
Microwave measuring technology for the sugar industry
D.-I.U. Klute - South AfricaFP8
Experience and utilisation of an on-line sugar colorimeter in a raw cane mill
S. King - AustraliaFP9
Simulation of the dynamic behaviour of a compartment of a continuous pan
D.J. Love - South AfricaFP12
Options for retrofitting white sugar milling (WSM) technology into existing raw sugar factories
C.R.C. Jensen and S.M. Kitching - South AfricaFP13
An assessment of post-harvest sucrose losses in sugarcane billets under sub-tropical conditions
S. Solomon, A.K. Shrivastava, P. Singh,I. Singh, A. Sawnani and C.P. Prajapati - IndiaFP14
Five years on - was the implementation of LIMS at the SMRI worth it?
S.N. Walford - South AfricaFP17 Aconitic acid ratio as a post-harvest whole-stalk green sugarcane age indicator
L. Corcodel and T. MulletFP19
Investigation into the use of the fractal concept for improving juice clarifier performance
R.C. Loubser and S.B. Davis - South AfricaFP20
A practical approach towards reducing the dextran levels in sugar at the Appleton Sugar Mill in jamaica
D. Foster and R. Bryan - JamaicaFP24
A new design of jigger system to improve vacuum pan performance
D.W. Rackemann and R. Broadfoot - AustraliaFP25
Improved pan stirrer performance through CFD modelling
D.W. Rackemann and R. Broadfoot - AustraliaFP26
Innovative production of white sugar from raw sugar during sugarcane shortage
S. Ravichandran, N. Dharmalingam,R. Ramamoorthy, C.K. Venkatesh and K. Sajith - IndiaFP28
Thirty years of progress in the South African sugar industry through benchmarking and technical innovation
S.B. Davis - South AfricaFP30
ISSCT Process Section Workshop: chairman report
V. Sens-Guichard - ReunionFP38
DRD - Dedini Refinado Direto (Dedini Direct Refined) - the refined sugar without refinery
J.L. Olivério, F.C. Boscariol and H.G. Filho - BrasilFP39
The effect of trash on the operation and performance of a raw sugar factory
G.A. Kent - AustraliaFP40
Optimising the performance of rotary sugar dryers through modelling and control
R.J. Steindl - AustraliaFP41
Aspects of mud thickening and handling in juice clarifiers
R.J. Steindl - AustraliaFP42 Measuring vacuum pan dynamics using pseudo random binary signals
D.J. Love - South AfricaFPP1
Successful innovation: results from the bosch continuous pan
B.St.C. Moor - South AfricaFPP6
The effective use of a chemical scale inhibitor for evaporator scale control
P.J. Allison, D.T. Munford, A. Palazzo and B. de Beer - South AfricaFPP8
Some notes on developments in high grade continuous pan boiling
M.A. Getaz, G. Journet, D.J. Love, andR.R. Sanders - UKFPP11
Discovery of sugarenes: a major commercial breakthrough for the sugar industry
K. Singh, and A. Deep - IndiaFPP13
On line devices for process monitoring and control of sugar production -the purity analyser-
M. Kuchejda, S. Yilmaz – GermanyFPP14
Adsorbents for sugarcane juice clarification: an innovative technology
R. Condemarin - PeruFPP15
Improving sugar quality and reducing process difficulties by emphasizing impurities rather than purity: minimizing soluble polysaccharides by use of biocides
V.M. Kulkarni - IndiaENGINEERING PAPERS
ABSTRACTSFE2_abstract
CANE TRACKING AND SAMPLING EQUIPMENT, AN UPDATE
By
F.Calboutin1 and S. Naidoo2
1Frank Calboutin & Associates
2South African Sugar Association
frank.calboutin@gmail.comKEYWORDS: Cane tracking, Sampling, Analysis.
Abstract
With the implementation of the Direct Analysis of Cane (DAC) method of cane sampling and analysis in the South African sugar industry over 30 years ago, it remains imperative that there is an accurate and reliable method of cane tracking and sampling.
Although the basic principles of cane tracking are the same, both the application and equipment used have changed.
The development of software and the availability of personal computers has revolutionised the manufacture of the cane tracking system.
The advent of Programmable Logic Controllers has allowed the sample point control system to be upgraded, and the development of a new type of pulse generator has improved performance and reliability.
By using video information, it is possible to transmit tracker information to any part of the factory.
The reliability that has been built into the cane tracker over the years ensures that the sampling information it provides forms a solid base for the systems it supports.
Future possible developments being considered are the linking of the tracker to the laboratory system, automatic tracking, and different sampling techniques.
FE3_abstract
SINTERED ALLOY POWDER CARBIDE AND TUNGSTEN CARBIDE MATERIALS FOR SHREDDER HAMMER TIPS
By
Joydeep Duttagupta 1 and T. R. Rama Mohan 2
1 IMCO Alloys Pvt. Ltd; INDIA
2Indian Institute of Technology Bombay, Formerly Professor; INDIA
imco@vsnl.com; jdgupta@imcoalloys.comKEYWORDS: Sintered alloy powder carbide, Chromium carbide, Sintered tungsten carbide, Twin cutter
Abstract
This paper describes a new design of replaceable tip for shredder hammers that provides improved life over the conventional white iron and tungsten carbide tips. The design incorporates a two-stage tip. The first stage is an alloy powder carbide material manufactured using an atomization process. This material is similar in composition to the conventional white iron, but the manufacturing process results in a finer grain with a more uniform dispersion of carbides, resulting in a harder and more wear resistant surface. The second stage is a tungsten carbide and cobalt alloy with a greater cobalt content for higher toughness. The tip can be rotated 180° to provide a second impact surface, thereby doubling the life of the tip.
Tests conducted at one Indian factory showed that the life of the new design of shredder hammer tip can be between 900 000 and 1 000 000 tonnes of cane.
FE4_abstract
FLUE GAS SCRUBBING EQUIPMENT FOR BAGASSE FIRED BOILERS
By
B. ST.C. MOOR
St Clair Design Consultants, Durban
moorb@bproj.co.zaKEYWORDS: Boilers, Flue gas, Scrubbers, Air pollution, Environment
Abstract
Over the past 50 years, sugar factories have been subjected to increasing environmental pressure to conform to new clean air requirements. In most cane sugar producing countries, legislation now imposes maximum limits on particulate emissions of 100 to 200 mg/Nm3 for new boilers.
The paper reviews various types of flue gas cleaning equipment, comparing their merits and disadvantages. Most traditional devices such as dry cyclones cannot achieve the new specifications. Of systems able to meet the targets, some are too costly or maintenance intensive for bagasse (or bagasse + fossil fuel) boilers, and wet scrubbers have been widely accepted as the most practical solution.
Various types of wet scrubbers are in service. These are compared in respect of separation efficiency, pressure drop, capital and operating costs, maintenance and reliability.
Measurements of particulates in gases from scrubbers in South Africa, Australia and the Philippines are reported. Operating issues such as pressure drops, turn down ratios, entrainment separation, ID fan selection and cleaning, and smuts separation from circulating water are discussed. Typical particle size distributions, their significance and causes of fine particles are discussed.
Experience in South Africa has led to the conclusion that sieve plate scrubbers are significantly better than other types of wet scrubber in bagasse boiler applications; 22 of the 36 wet scrubbers in the industry are now of this type.
FE5_final
FIBRE EXTRACTED WITH JUICE FROM MILLS –AN OMISSION IN MILLING THEORY
By
B. St.C. MOOR
Bosch Projects, Durban
moorb@bproj.co.zaKEYWORDS: Milling theory, Mill capacity, Fibre, Mill settings, Cush-cush
Abstract
From a recent review of literature on various aspects of sugar cane milling, it was apparent that traditional milling theory and most milling engineers / technologists ignore the fibre dropped with the juice extracted from mills. The quantity is much greater than generally assumed and has significant implications for issues such as mill capacities, mill settings, extraction, configuration of cush cush screening systems and classical milling theory (compaction, fibre fill ratios and reabsorption).
There is very little reported data on fibre dropped from mills. Measurements were therefore commissioned at several milling tandem and diffuser dewatering mills. Results are reported, showing that typically 5% to 15% of fibre entering the mill exits with extracted juice. Factors influencing the wide variation in amounts include cane quality, preparation, mill configuration (number of rolls, Messchaert knives, etc.), mill and trash plate condition and settings and imbibition rates.
Implications of this fibre are illustrated using a model of a milling tandem. Some conclusions are:
- The feed opening of the second mill of most tandems usually processes 15% to 30% more fibre than enters the first mill of the tandem;
- With some cush-cush configurations, this figure can be as much as 70%;
- This additional fibre has implications for both mill capacity and extraction;
- Contrary to the usual assumption in mill settings, the fibre rate through the feed opening of a mill is usually 5% to 15% greater than that through the discharge opening. This greater fibre rate is unwittingly allowed for by empirical factors in the common mill setting formulae.
- The calculations used by mill engineers to monitor performance by compaction ratios and reabsorption are also in error, but the techniques work because the errors are consistent.
FE8_abstract
THE CONVERSION OF A BMA DIFFUSER TO A BOSCH PROJECTS CHAINLESS DIFFUSER –
THE FIRST SEASON’S EXPERIENCE
By
K.E. SCHRÖDER 1, I. VOIGT2 AND B.ST.C. MOOR2
1UCL Ltd, Dalton
2Bosch Projects, Durban
1 engineering@ucl.co.za, 2 VoigtI@bproj.co.za moorb@bproj.co.zaKEYWORDS: Diffusers, diffusion, extraction, maintenance costs, chainless diffuser.
Abstract
During 2005, the UCL sugar factory was faced with the prospect of major costs on their BMA diffuser, including a chain replacement, drive repairs and the possible prohibitive cost of future capacity expansion. Bosch Projects introduced UCL to the concept of the chainless diff user, and a study showed that their BMA diffuser could be converted to the chainless design at a lower cost than the alternative maintenance costs. The conversion would also allow for cost-effective future expansions.
A pilot plant was designed and installed at the UCL factory to test the chainless diffuser concept and to gather data for the conversion of the BMA diffuser. After successful trials, the design for the conversion of the BMA diffuser was carried out by Bosch Projects and the conversion performed in January and February 2006, with the milling season starting late in February. Performance results since commissioning are reported and compared with the diffuser performance prior to the conversion. Maintenance experience and costs are reported.
Because this was the first installation of a novel design, compromises were made to allow for re-instatement of the old diffuser had this been necessary. In particular, the old perforated floor was initially retained, with the new chainless deck installed above it. This created a chamber in which fibrous deposits accumulated, causing blockages and sucrose destruction.
At the time of writing, the chainless diffuser has been in operation for 9 months, achieving comparable throughput performance despite the reduced bed height. The extraction performance is a little less than that of the BMA diffuser at this time. This is explained by the initial compromises. Teething problems and design shortcomings have been identified. Some of these have been corrected while the rest will be addressed during the 2006-07 off-crop.
This paper reviews the patented chainless diffuser concept, describes the pilot plant and the conversion of the BMA diffuser to a Bosch Projects Chainless Diffuser, and the operational and maintenance performance since commissioning.
FE9_abstract
THE DETECTION OF SUGAR TRACES IN THE TONGAAT HULETT REFINERY CONDENSATES BY NIR SPECTROSCOPY
By
G.R.E. LIONNET1, M.M. MAVUSO1, N. OOSTHUIZEN2, P. F. NIEUWOUDT2 and D. SEARL3
1 Tongaat-Hulett Sugar, TEG, Tongaat, South Africa
2 Bruker (Pty) LTD, South Africa
3 Hulett Refineries, Durban, South Africa
raoul.lionnet@huletts.co.zaKEYWORDS: Condensates, Sugar traces, NIR spectroscopy
Abstract
The presence of sucrose in condensates used as boiler feed water in raw sugar factories can be detected using conductivity since cane juice contains enough inorganic species to measurably change the conductivity of the condensate; this approach is not possible at the Tongaat Hulett Refinery because of the high purity of the liquors. This refinery uses a total organic carbon analyser; it oxidizes soluble organic matter in the condensate to carbon dioxide that is then detected quantitatively and converted by stoichiometry to sucrose concentrations. Chemicals are needed for the oxidation and the time required for the reactions is about three minutes for a sample, requiring large volumes of condensates to be held in tanks.
A FT-NIR spectrometer with a probe for liquids was investigated as an alternative, since it does not require chemicals and has a sample processing time of about 30 seconds; calibrations are required but this can now be in terms of sucrose concentration.
The spectrometer was run in parallel with the total organic carbon analyser for a period of four months. Installation, commissioning and day-to-day operations were simple and problem free; maintenance was minimal. Calibrations, using the phenol-sulfuric acid method for sugar traces, were done regularly.
The results obtained show that the equipment and technique are robust and easy to operate; calibrations are essential but this is the case with most sugar trace detection methods. Accuracy in NIR systems depends essentially on the quality of the calibrations; the NIR instrument could report sugar traces at concentrations of 10 and 20 mg/L, as required by this application, within acceptable limits. Variations in sample temperature were found to impact on the accuracy but this effect can be eliminated.
FE10_final
DETECTION OF SUCROSE IN BOILER FEED WATER
By
M.A. GOOCH and A. WIENESE
Sugar Milling Research Institute, c/o University of KwaZulu-Natal, Durban 4041
mgooch@smri.orgKEYWORDS: boiler condensate measurement
Abstract
Numerous authors have outlined the importance of preventing sucrose entrained in condensate from entering the boilers particularly where higher-pressure boilers are in use. The condensate from a raw sugar mill, sugar refinery or a raw sugar mill with an attached back end refinery contains different types and quantities of impurities. Because of this, the appropriate technology to measure impurity levels varies between applications. This paper is a review of the different techniques to detect the contamination of sucrose in boiler feed water.
FE11_abstract
Integrated beet and cane sugar processing with high cogeneration efficiency
PEDRO AVRAM, BORIS MORGENROTH AND STEFAN PFAU
IPRO Industrieprojekt GmbH, Celler Straße 67, 38114 Braunschweig, Germany
Tel: +49 (531) 59003-0, Fax: +49 (531) 59003-45,
E-mail: Avram@ipro-bs.de, Morgenroth@ipro.de, Pfau@ipro-bs.deKEYWORDS: Integrated beet and cane sugar plant, low steam consumption, cogeneration
Abstract
Due to water scarcity on one hand and possibilities to increase annual factory running time on the other, it has proven worthwhile to consider integrated beet and cane processing in some countries where climatic conditions are suitable for both crops.
The paper gives an overview of selected and applicable technologies driving the energy demand of an integrated beet and cane processing plant to its minimum. As a result, the plant is self-sufficient in fuel usage and also offers a sizable amount of power export (cogeneration). The surplus bagasse from the cane crop (typically 150 to 180 days) allows for providing steam during the beet campaign (typically 60 to 80 days) and even some off-crop usage for refining raw sugar as well.
In order to keep investment costs at reasonable levels, careful design of the dual-use plant is required, as well as making maximum use of equipment that can handle both beet and cane intermediate products. The different purities and colour levels of cane and beet juices require somewhat different treatment in juice purification and in boiling procedures, but the majority of the process steps are identical. The additional cost of an efficient dual-use plant is easily compensated by the benefits in increased sugar output, sale of electricity and beet-pulp as a valuable fodder.
FE14_abstract
UNIQUE TWO-ROLLER MILL COMBINATION - THE CMR MILL -
By
BHAUSAHEB B. NIKAM and SACHIN B. NIKAM
Ulka Industries Ltd.,1233, Apte Road,Pune – 411 004,Maharashtra State, India
sachinbnikam@rediffmail.com, info@ulkaind.comKEYWORDS: Trash plate-less, compact multi-roller mill (CMR mill), toothed roller feeder (TRF), juice extraction, fibre loading.
Abstract
The milling station is a major power consuming station. Efforts are being made to improve mill designs to reduce power consumption and enhance efficiency.
As an effective alternative to conventional three-roller mills, two-roller mills of various types have been introduced in the cane sugar industry. However, existing two-roller mill designs were judged to have ineffective mill feeding systems. This issue was considered the crucial factor requiring further development of two-roller milling technology. The other disadvantage of existing two-roller mill designs was that they could not be readily used in existing mill tandems using existing drives.
Experiments carried out in India led to designing[1] trash plate-less two-roller mills with pressure chute-less and upgradeable multi-roller mill feeding systems, named Compact Multi Roller (CMR) mills.
These two-roller mills have been designed to be readily installed on existing foundations in place of existing conventional mills using existing drives. Thus the factories can replace their existing mills at a minimal cost.
At present, there are six installations of CMR mills. These installations showed enhanced efficiency, reduced bagasse moisture content of about 47.5%, and 25% less power than conventional mills. This paper deals with details of CMR mills, their configuration, and working results.
[1] Designed and patented by Ulka Industries, India; Indian patent No. 186646, -other international patents filed/pending
FE15_abstract
MEASUREMENTS AND CFD SIMULATION OF THE FLOW IN VACUUM PANS
By
L.F. ECHEVERRI1, P.W. REIN1, and S. ACHARYA2
1Audubon Sugar Institute, LSU Agricultural Center, Louisiana, USA
2Mechanical Engineering Dept. LSU, Louisiana, USA
lechev1@lsu.eduKEYWORDS: Crystallization, vacuum pans, circulation, CFD.
Abstract
The evaporative crystallizers or vacuum pans used by the sugar industry have been developed during the last two centuries using an empirical approach that has led to the designs of batch, and more recently continuous pans in use today. Lack of detailed information on the process has led to an empirical development of the technology, where engineers’ guesses and trial-and-error have been the main development tools. This paper presents experimental and Computational Fluid Dynamics (CFD) results obtained in the study of the circulation in vacuum pans, where the physical fundamentals behind CFD simulations are applied to obtain an educated solution for the complex multiphase flow within the pans. It is observed that a thermo-hydraulic boiling instability occurs in the calandria tubes, resulting in intermittent vaporization and corresponding oscillations of the flow. The CFD solutions have indicated possible circulation patterns and shown reasonable agreement with measurements performed in a full-scale continuous pan. In the same way, the predictions have shown agreement with observations reported in previous studies.
FE16_abstract
CHARACTERIZATION OF POLLUTING EMISSIONS FROM SUGARCANE BAGASSE BOILERS AND THEIR REMOVAL
By
F.N. TEIXEIRA,
Departamento de Ciências Térmicas e Fluídos – DCTEF, Universidade Federal de São João del Rei –
UFSJ, Minas Gerais, Brazil
flavio@ufsj.edu.br
E. OLIVARES-GÓMEZ, E.E. SILVA LORA.
Núcleo de Excelência em Geração Termelétrica e Distribuída – NEST, Instituto de Engenharia Mecânica – IEM, Universidade Federal de Itajubá – UNIFEI, Minas Gerais, Brazil
egomez@unifei.edu.br; electo@unifei.edu.br
A.L. BRITO SAUVANELL
Centro de Eficiencia Energética – CEEFE, Facultad de Ingenieria Mecánica –
FIM, Universidad de Oriente, Santiago de Cuba, Cuba
angelluisb@gmail.comKEYWORDS: bagasse boilers, nitrogen oxides, particulates, polluting emissions
Abstract
After analysing the available information on the characterization of the polluting emissions from bagasse boilers, it was realized that there are only a few publications and only limited reliable data. In addition, they are scattered and characterized in such a way that generalization is not possible. Based on experimental data obtained by the authors and from literature about polluting emissions (NOx and particulates) from bagasse boilers, this work allows the assessment of NOx discharges in relation to the operational parameters such as air excess coefficient and oxygen content. It was possible to obtain data about the relation between the particulates concentration in the flue gas and the type of dust collector systems applied. From the results obtained, recommendations could be formulated for equipment manufacturers regarding the criteria for modelling, design, selection, operation, and evaluation of different dust collector systems for bagasse boilers.
FE17_abstract
HARD FACED WELDED TIPS IN SHREDDER HAMMERS - TECHNICAL AND ECONOMICAL PERFORMANCE
By
A.L. GÓMEZ, C.F. CAÑÓN, D. E. RAMÍREZ
CENICAÑA- COLOMBIA
algomez@cenicana.orgKEYWORDS: Hammer, Shredder, Hardfacing alloys, Welding, Maintenance
Abstract
Shredder hammer maintenance is one of the main targets in cost reduction efforts in cane crushing factories. Recent developments in shredder hammer technology remain far from improving the current situation in the matter of wear in cane preparation machinery. Trials with very hard but brittle materials such as ceramics and tungsten carbide tips had left white iron (FeCrC) alloys as the most cost-effective choice, especially when used as replaceable mild steel blocks with brazed tips. In an effort to develop a more cost-effective solution, a combination of the replaceable block and Flux-Cored Arc Welding (FCAW) (possible to be repaired a few times) was evaluated under factory trials and with a comprehensive analysis that includes maintenance costs, energy and pol losses in bagasse.
Wear performance of welded tips made with hardfacing alloys and bolted to shredder hammers is reported and compared to commercially available tips and other conventional technologies. It was found that welded tips are likely to be cost effective under the evaluated conditions and a complete welding procedure was developed for production and maintenance of the tips.
FE18_abstractSTEADY-STATE SIMULATION OF A COMPLETE SUGAR MILL WITH ETHANOL PLANT By A.L. GOMEZ, A. CARVAJAL, C.F. CAÑÓN, D. BARRIENTOS AND C.O. BRICEÑO Cenicaña-Colombia algomez@cenicana.orgKEYWORDS: Energy Management, Modelling, Steady State Simulation.
Abstract
Ethanol production from differently combined feed stock such as clarified juice, syrup, and B molasses presents new parameters for energy management programs in the factories. Using data from five commissioned ethanol fuel distilleries and two cogeneration projects in planning and by request of the factories, a comprehensive computational tool, CENIPROF, based on VB (Visual Basic®[1]) and spread sheets, has been developed for Colombian mills, applicable for complete factories on an individual basis. This paper reports on results of different usable computer modules, sensitivity and impact simulations of technological changes. CENIPROF has proven useful and relatively simple for use by factory personnel at the engineering and operational level.
[1] A programming language created by Microsoft as a version of BASIC
FE-19_abstract
TORQUE SIGNATURES IN CRUSHING MILLS
By
A.L. GÓMEZ, C.F. CAÑÓN, L.F. ROSERO
