Improving combustion stability in sugar factory boilers

Reliable operation of a sugar factory boiler station is essential for efficient and timely processing of the cane supply. Sugar factory boilers have to contend with changes in fuel quality caused by variations in performance of the extraction station, different cane varieties and associated agronomic factors along with fluctuations in factory steam demand. These variations can affect the stability of combustion in boiler furnaces leading to reductions in boiler steam output and large furnace pressure fluctuations that can cause serious damage. This paper investigates the causes of unstable combustion, discusses aspects of boiler design that make a boiler more susceptible to unstable combustion and uses modelling to evaluate different options for improving combustion stability.

Measuring, modelling and understanding the mechanical behavior of bagasse

In the Australian sugar industry, sugar cane is smashed into a straw like material by hammers before being squeezed between large rollers to extract the sugar juice. The straw like material is initially called prepared cane and then bagasse as it passes through successive roller milling units. The sugar cane materials are highly compressible, have high moisture content, are fibrous, and they resemble some peat soils in both appearance and mechanical behaviour. A promising avenue to improve the performance of milling units for increased throughput and juice extraction, and to reduce costs is by modelling of the crushing process. To achieve this, it is believed necessary that milling models should be able to reproduce measured bagasse behaviour. This investigation sought to measure the mechanical (compression, shear, and volume) behaviour of prepared cane and bagasse, to identify limitations in currently used material models, and to progress towards a material model that can predict bagasse behaviour adequately. Tests were carried out using a modified direct shear test equipment and procedure at most of the large range of pressures occurring in the crushing process. The investigation included an assessment of the performance of the direct shear test for measuring bagasse behaviour. The assessment was carried out using finite element modelling. It was shown that prepared cane and bagasse exhibited critical state behavior similar to that of soils and the magnitudes of material parameters were determined. The measurements were used to identify desirable features for a bagasse material model. It was shown that currently used material models had major limitations for reproducing bagasse behaviour. A model from the soil mechanics literature was modified and shown to achieve improved reproduction while using magnitudes of material parameters that better reflected the measured values. Finally, a typical three roller mill pressure feeder configuration was modelled. The predictions and limitations were assessed by comparison to measured data from a sugar factory.

Milling and diffusion extraction : theory and practice

AN ENGINEERING Workshop was held from 21 to 24 November 2006 in Veracruz, Mexico. Forty delegates from 12 countries attended the workshop on theory and practice of milling and diffusion extraction. This report provides a general overview of activities undertaken during that workshop which consisted of five technical sessions over two days with presentations and discussions plus two days of field and factory visits. Topics covered during the technical sessions included: power transmissions, cane preparation, diffusers, mills, and a comparison of milling and diffusion.

Douglas Shire Water Quality Monitoring Strategy: Final Report: a Report to Douglas Shire Council and the Department of the Environment and Heritage

This report describes results and conclusions from the monitoring component of the Douglas Shire Council (DSC) water quality project. The components of this project that this report addresses are: • Site selection and installation of in-stream and off-paddock automatic water quality monitoring equipment in the Douglas Shire. • Design of appropriate sampling strategies for automatic stations. • Estimation of loads of suspended sediment, total nitrogen and total phosphorus in rivers and also estimation of the changes in nutrient loads from sugar cane under different fertilizer application rates. • Development of a community-based water quality sampling program to complement the automatic sampling efforts. • Design of an optimised, long-term water quality monitoring strategy.

Summarising and reporting sugarcane locomotive run statistics from TOTools and GPS data

The majority of sugar mill locomotives are equipped with GPS devices from which locomotive position data is stored. Locomotive run information (e.g. start times, run destinations and activities) is electronically stored in software called TOTools. The latest software development allows TOTools to interpret historical GPS information by combining this data with run information recorded in TOTools and geographic information from a GIS application called MapInfo. As a result, TOTools is capable of summarising run activity details such as run start and finish times and shunt activities with great accuracy. This paper presents 15 reports developed to summarise run activities and speed information. The reports will be of use pre-season to assist in developing the next year's schedule and for determining priorities for investment in the track infrastructure. They will also be of benefit during the season to closely monitor locomotive run performance against the existing schedule.

Planning and governance approaches for protecting World Heritage Areas: A comparison of the Great Barrier Reef and the Florida Everglades

The focus of this paper is on two World Heritage Areas: the Great Barrier Reef in Queensland, Australia and the Everglades in Florida. While both are World Heritage listed by the UNESCO, the Everglades is on the "World Heritage in Danger" list and the Great Barrier Reef could be on this list within the next year if present pressures continue. This paper examines the planning approaches and governance structures used in these two areas (Queensland and Florida) to manage the growth and development pressures. To make the analysis manageable, given the scale of these World Heritage areas, case studies at the local government level will be used: the Cairns Regional Council in Queensland and Monroe County in Florida. The case study analysis will involve three steps: (1) examination of the various plans at the federal, state, local levels that impact upon environmental quality in the Great Barrier Reef and Everglades; (2) assessing the degree to which these plans have been implemented; and (3) determine if (and how) the plans have improved environmental quality. In addition to the planning analysis we will also examine the governance structures (Lebel et al. 2006) within which planning operates. In any comparative analysis context is important (Hantrais 2009). Contextual differences between Queensland and Florida have previously been examined by Sipe, et al. (2007) and will be used as the starting point for this analysis. Our operating hypothesis and preliminary analysis suggests that the planning approaches and governance structures used in Florida and Queensland are considerably different, but the environmental outcomes may be similar. This is based, in part, on Vella (2004) who did a comparative analysis of environmental practices in the sugar industry in Florida and Queensland. This research re-examines this hypothesis and broadens the focus beyond the sugar industry to growth and development more broadly.

Tracking locomotive position to evaluate sugarcane railway schedules and predict arrival time

This research utilised software developed for managing the Australian sugar industry's cane rail transport operations and GPS data used to track locomotives to ensure safe operation of the railway system to improve transport operations. As a result, time usage in the sugarcane railway can now be summarised and locomotive arrival time to sidings and mills can be predicted. This information will help the development of more efficient run schedules and enable mill staff and harvesters to better plan their shifts ahead, enabling cost reductions through better use of available time.

Managing milling train operation and performance

This paper discusses the main milling train management tasks necessary for maintaining good extraction performance through a season. The main activities discussed are making week by week decisions about shredder and mill setting adjustments, and selecting preseason mill settings. To maintain satisfactory milling train extraction performance, the main factors affecting extraction should be examined: cane preparation with pol in open cells or shredder torque, delivery nip compaction through the load or torque controller outputs such as roll lift, feed chute flap position or pressure feeder to mill speed ratio, and added water rate. To select mill settings for the coming season, delivery nip compaction and feed chute exit compaction can be inferred from the previous seasons.

The nutritional profile of baby and toddler food products sold in Australian supermarkets

Background/Aims To examine the nutritional profile of baby and toddler foods sold in Australia. Methods Nutrient information for baby and toddler foods available at Australian supermarkets was collected between August and December 2013. Levels of declared energy, total fat, saturated fat, total sugar, sodium and estimated added sugar were examined, as well as the presence of additional micronutrients on the label. The Health Star Rating (HSR) system was used to determine nutritional quality. The range of products on offer was also examined by product type and by the age category for which the product was marketed. Results Of the 309 products included, 29 % were fortified. On a per 100 g basis, these 309 products provided a mean (±SD) of 476 ± 486 kJ, 1.6 ± 2.4 g total fat, 10.7 ± 12.2 g total sugar, 2.7 ± 7.4 g added sugar, and 33.5 ± 66.5 mg sodium. Fruit-based products or products with fruit listed as an ingredient (58 %) were the predominant product type. On the nutrition label, 42 % displayed at least one additional micronutrient while 37 % did not display saturated fat. The most common HSR was four stars (45 %) and 6? months was the most commonly identified targeted age group (36 %). Conclusions The majority of baby and toddler foods sold in Australian supermarkets are ready-made fruit-based products aimed at children under 12 months of age. Baby and toddler foods are overlooked in public policy discussions pertaining to population nutrient intake but their relatively high sugar content deriving from fruits requires close attention to ensure these foods do not replace other more nutrient dense foods, given children have an innate preference for sweet tastes.

Socioeconomic inequalities in diet and bodyweight: Evidence, causes, and intervention options

Diets low in fruits, vegetables, and whole grains, and high in saturated fat, salt, and sugar are the major contributors to the burden of chronic diseases globally. Previous research, and studies in this issue of Public Health Nutrition (PHN), show that unhealthy diets are more commonly observed among socioeconomically disadvantaged groups, and are key contributors to their higher rates of chronic disease. Most research examining socioeconomic inequalities in diet and bodyweight has been descriptive, and has focused on identifying the nature, extent, and direction of the inequalities. These types of studies are clearly necessary and important. We need however to move beyond description of the problem and focus much more on the question of why inequalities in diet and bodyweight exist. Furthering our understanding of this question will provide the necessary evidence-base to develop effective interventions to reduce the inequalities. The challenge of tackling dietary inequalities however doesn’t finish here: a maximally effective approach will also require equity-based policies that address the unequal population-distribution of social and economic resources, which is the fundamental root-cause of dietary and bodyweight inequalities.