Proposal for modernization of Robert evaporators

Hans Joachim Praus

It is proposed to convert existing Robert evaporators into Trebor evaporators. Trebor evaporators work as falling film evaporators with the well-known thermal and technological advantages. When converting a Robert evaporator into a Trebor evaporator, the heating steam inlet and the vapour outlet as well as the condensate drain remain in their original positions. If necessary, the positions of the juice inlet and outlet nozzles are changed, and two additional nozzles and a circulation juice pump are required. These changes are cheaper than installing a new falling film evaporator.

2021 (146) 51–54
Language: ENG

Process design and equipment selection for optimized steam and power concepts – the “zero” process steam sugar factory

Boris Morgenroth; Thomas Stark; Julian Pelster; Harjeet Singh Bola

maximize sugar recovery and export power along with manpower optimization is a must for sugar factories to survive under difficult conditions and to earn additional revenues. The process steam demand of greenfield and revamped plants has been reduced to levels of 32–38% from originally more than 50% steam on cane in the case of the brownfield plants. In addition, significant improvement in the power requirement of the plants has been achieved. Bagasse drying offers a good potential to improve the power export. Different available concepts are compared with a focus on bagasse steam drying and low temperature bagasse drying. In order to set up an optimized highly efficient plant or to optimize an existing plant to achieve competitive benchmarks, good process design and the right equipment selection are very important. Experience has been gained with multiple stage or double effect crystallization in the beet sugar industry offering further steam optimization potential. Vapour recompression is also an option to substitute live steam by electrical power. This even provides options to reduce the steam demand from the power plant for the sugar process down to zero. Key aspects concerning the process design and equipment selection are described.

2021 (146) 40–50
Language: ENG

Structure and chemical composition of exopolysaccharides of frost-damaged sugar beet

Aneta Antczak-Chrobot; Maciej Wojtczak

In this research paper, development of a procedure of isolation of exopolysaccharides from frost-damaged beet and an analysis of structural and chemical composition of polymers isolated from sugar beet of different origin are presented. Total acid hydrolysis degradation integrated with HPAEC-ED analysis has been utilized to confirm the monomeric composition of the separated polysaccharides. The implementation of NMR spectral analysis and SEC chromatography of the structure of exopolysaccharides has been investigated. The results demonstrate that the chemical composition and structure of exopolysaccharides depend on their origin. Typical exopolysaccharides from Central European beet roots consist mainly of glucose monomers – and they have low branched structure – about 90% of a-1,6 linkage which is typical for dextran. The exopolysaccharides isolated from Swedish beet are characterized by 50–60% fructose monomers. They contain only about 65% a-1,6 linkages. Exopolysaccharides extracted from various origin beet differ in average molecular mass. The molecular distribution is not normal.

2021 (146) 34–39
Language: ENG

Direct production of less than 50 IU white sugar at a cane sugar plant

Narendranath Mullapudi

With the selection of available process equipment and practicing best operating conditions, sugar of less than 50 IU can be produced at a cane mill without back-end refinery. Cane diffusers are being used which are energy efficient and produce cane juice with low suspended solids. The double sulphitation process is followed using the ejector system to obtain a better colour and turbidity removal. High efficiency, low residence time and low turbulence settling clarifier is being used for juice clarification. Syrup clarification is also used to polish the syrup further without using any colour precipitants. A 3½ stage crystallization scheme is employed. For A massecuite a seed magma of B2 sugar is used. B2 sugar is produced from B sugar as seed and syrup and dissolved B and C sugar is used. Purity of Amassecuite is maintained around 90% producing a sugar of below 50 IU with 70% of the crystallizate having a size of 1200–1700 µm with low residual SO2 content.

2020 (145) 729–735
Language: ENG

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